diff options
Diffstat (limited to 'kernel')
169 files changed, 16075 insertions, 8943 deletions
diff --git a/kernel/.gitignore b/kernel/.gitignore index ab4f1090f437..b3097bde4e9c 100644 --- a/kernel/.gitignore +++ b/kernel/.gitignore @@ -4,3 +4,4 @@ config_data.h config_data.gz timeconst.h +hz.bc diff --git a/kernel/Makefile b/kernel/Makefile index 6c072b6da239..271fd3119af9 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -7,7 +7,7 @@ obj-y = fork.o exec_domain.o panic.o printk.o \ sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \ signal.o sys.o kmod.o workqueue.o pid.o task_work.o \ rcupdate.o extable.o params.o posix-timers.o \ - kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \ + kthread.o wait.o sys_ni.o posix-cpu-timers.o mutex.o \ hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \ notifier.o ksysfs.o cred.o \ async.o range.o groups.o lglock.o smpboot.o @@ -24,10 +24,9 @@ endif obj-y += sched/ obj-y += power/ +obj-y += cpu/ -ifeq ($(CONFIG_CHECKPOINT_RESTORE),y) -obj-$(CONFIG_X86) += kcmp.o -endif +obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o obj-$(CONFIG_FREEZER) += freezer.o obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_STACKTRACE) += stacktrace.o @@ -127,11 +126,19 @@ $(obj)/config_data.h: $(obj)/config_data.gz FORCE $(obj)/time.o: $(obj)/timeconst.h -quiet_cmd_timeconst = TIMEC $@ - cmd_timeconst = $(PERL) $< $(CONFIG_HZ) > $@ +quiet_cmd_hzfile = HZFILE $@ + cmd_hzfile = echo "hz=$(CONFIG_HZ)" > $@ + +targets += hz.bc +$(obj)/hz.bc: $(objtree)/include/config/hz.h FORCE + $(call if_changed,hzfile) + +quiet_cmd_bc = BC $@ + cmd_bc = bc -q $(filter-out FORCE,$^) > $@ + targets += timeconst.h -$(obj)/timeconst.h: $(src)/timeconst.pl FORCE - $(call if_changed,timeconst) +$(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE + $(call if_changed,bc) ifeq ($(CONFIG_MODULE_SIG),y) # @@ -153,23 +160,7 @@ kernel/modsign_certificate.o: signing_key.x509 extra_certificates # fail and that the kernel may be used afterwards. # ############################################################################### -sign_key_with_hash := -ifeq ($(CONFIG_MODULE_SIG_SHA1),y) -sign_key_with_hash := -sha1 -endif -ifeq ($(CONFIG_MODULE_SIG_SHA224),y) -sign_key_with_hash := -sha224 -endif -ifeq ($(CONFIG_MODULE_SIG_SHA256),y) -sign_key_with_hash := -sha256 -endif -ifeq ($(CONFIG_MODULE_SIG_SHA384),y) -sign_key_with_hash := -sha384 -endif -ifeq ($(CONFIG_MODULE_SIG_SHA512),y) -sign_key_with_hash := -sha512 -endif -ifeq ($(sign_key_with_hash),) +ifndef CONFIG_MODULE_SIG_HASH $(error Could not determine digest type to use from kernel config) endif @@ -182,10 +173,10 @@ signing_key.priv signing_key.x509: x509.genkey @echo "### needs to be run as root, and uses a hardware random" @echo "### number generator if one is available." @echo "###" - openssl req -new -nodes -utf8 $(sign_key_with_hash) -days 36500 -batch \ - -x509 -config x509.genkey \ + openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \ + -batch -x509 -config x509.genkey \ -outform DER -out signing_key.x509 \ - -keyout signing_key.priv + -keyout signing_key.priv 2>&1 @echo "###" @echo "### Key pair generated." @echo "###" diff --git a/kernel/acct.c b/kernel/acct.c index 051e071a06e7..8d6e145138bb 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -205,7 +205,7 @@ static int acct_on(struct filename *pathname) if (IS_ERR(file)) return PTR_ERR(file); - if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) { + if (!S_ISREG(file_inode(file)->i_mode)) { filp_close(file, NULL); return -EACCES; } @@ -540,6 +540,12 @@ static void do_acct_process(struct bsd_acct_struct *acct, ac.ac_swaps = encode_comp_t(0); /* + * Get freeze protection. If the fs is frozen, just skip the write + * as we could deadlock the system otherwise. + */ + if (!file_start_write_trylock(file)) + goto out; + /* * Kernel segment override to datasegment and write it * to the accounting file. */ @@ -554,6 +560,7 @@ static void do_acct_process(struct bsd_acct_struct *acct, sizeof(acct_t), &file->f_pos); current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim; set_fs(fs); + file_end_write(file); out: revert_creds(orig_cred); } @@ -566,6 +573,7 @@ out: void acct_collect(long exitcode, int group_dead) { struct pacct_struct *pacct = ¤t->signal->pacct; + cputime_t utime, stime; unsigned long vsize = 0; if (group_dead && current->mm) { @@ -593,8 +601,9 @@ void acct_collect(long exitcode, int group_dead) pacct->ac_flag |= ACORE; if (current->flags & PF_SIGNALED) pacct->ac_flag |= AXSIG; - pacct->ac_utime += current->utime; - pacct->ac_stime += current->stime; + task_cputime(current, &utime, &stime); + pacct->ac_utime += utime; + pacct->ac_stime += stime; pacct->ac_minflt += current->min_flt; pacct->ac_majflt += current->maj_flt; spin_unlock_irq(¤t->sighand->siglock); diff --git a/kernel/async.c b/kernel/async.c index 6f34904a0b53..61f023ce0228 100644 --- a/kernel/async.c +++ b/kernel/async.c @@ -57,65 +57,48 @@ asynchronous and synchronous parts of the kernel. #include <linux/slab.h> #include <linux/workqueue.h> +#include "workqueue_internal.h" + static async_cookie_t next_cookie = 1; -#define MAX_WORK 32768 +#define MAX_WORK 32768 +#define ASYNC_COOKIE_MAX ULLONG_MAX /* infinity cookie */ -static LIST_HEAD(async_pending); -static ASYNC_DOMAIN(async_running); -static LIST_HEAD(async_domains); +static LIST_HEAD(async_global_pending); /* pending from all registered doms */ +static ASYNC_DOMAIN(async_dfl_domain); static DEFINE_SPINLOCK(async_lock); -static DEFINE_MUTEX(async_register_mutex); struct async_entry { - struct list_head list; + struct list_head domain_list; + struct list_head global_list; struct work_struct work; async_cookie_t cookie; - async_func_ptr *func; + async_func_t func; void *data; - struct async_domain *running; + struct async_domain *domain; }; static DECLARE_WAIT_QUEUE_HEAD(async_done); static atomic_t entry_count; - -/* - * MUST be called with the lock held! - */ -static async_cookie_t __lowest_in_progress(struct async_domain *running) +static async_cookie_t lowest_in_progress(struct async_domain *domain) { - async_cookie_t first_running = next_cookie; /* infinity value */ - async_cookie_t first_pending = next_cookie; /* ditto */ - struct async_entry *entry; - - /* - * Both running and pending lists are sorted but not disjoint. - * Take the first cookies from both and return the min. - */ - if (!list_empty(&running->domain)) { - entry = list_first_entry(&running->domain, typeof(*entry), list); - first_running = entry->cookie; - } + struct list_head *pending; + async_cookie_t ret = ASYNC_COOKIE_MAX; + unsigned long flags; - list_for_each_entry(entry, &async_pending, list) { - if (entry->running == running) { - first_pending = entry->cookie; - break; - } - } + spin_lock_irqsave(&async_lock, flags); - return min(first_running, first_pending); -} + if (domain) + pending = &domain->pending; + else + pending = &async_global_pending; -static async_cookie_t lowest_in_progress(struct async_domain *running) -{ - unsigned long flags; - async_cookie_t ret; + if (!list_empty(pending)) + ret = list_first_entry(pending, struct async_entry, + domain_list)->cookie; - spin_lock_irqsave(&async_lock, flags); - ret = __lowest_in_progress(running); spin_unlock_irqrestore(&async_lock, flags); return ret; } @@ -127,20 +110,10 @@ static void async_run_entry_fn(struct work_struct *work) { struct async_entry *entry = container_of(work, struct async_entry, work); - struct async_entry *pos; unsigned long flags; ktime_t uninitialized_var(calltime), delta, rettime; - struct async_domain *running = entry->running; - /* 1) move self to the running queue, make sure it stays sorted */ - spin_lock_irqsave(&async_lock, flags); - list_for_each_entry_reverse(pos, &running->domain, list) - if (entry->cookie < pos->cookie) - break; - list_move_tail(&entry->list, &pos->list); - spin_unlock_irqrestore(&async_lock, flags); - - /* 2) run (and print duration) */ + /* 1) run (and print duration) */ if (initcall_debug && system_state == SYSTEM_BOOTING) { printk(KERN_DEBUG "calling %lli_%pF @ %i\n", (long long)entry->cookie, @@ -157,23 +130,22 @@ static void async_run_entry_fn(struct work_struct *work) (long long)ktime_to_ns(delta) >> 10); } - /* 3) remove self from the running queue */ + /* 2) remove self from the pending queues */ spin_lock_irqsave(&async_lock, flags); - list_del(&entry->list); - if (running->registered && --running->count == 0) - list_del_init(&running->node); + list_del_init(&entry->domain_list); + list_del_init(&entry->global_list); - /* 4) free the entry */ + /* 3) free the entry */ kfree(entry); atomic_dec(&entry_count); spin_unlock_irqrestore(&async_lock, flags); - /* 5) wake up any waiters */ + /* 4) wake up any waiters */ wake_up(&async_done); } -static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct async_domain *running) +static async_cookie_t __async_schedule(async_func_t func, void *data, struct async_domain *domain) { struct async_entry *entry; unsigned long flags; @@ -193,19 +165,25 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct a spin_unlock_irqrestore(&async_lock, flags); /* low on memory.. run synchronously */ - ptr(data, newcookie); + func(data, newcookie); return newcookie; } + INIT_LIST_HEAD(&entry->domain_list); + INIT_LIST_HEAD(&entry->global_list); INIT_WORK(&entry->work, async_run_entry_fn); - entry->func = ptr; + entry->func = func; entry->data = data; - entry->running = running; + entry->domain = domain; spin_lock_irqsave(&async_lock, flags); + + /* allocate cookie and queue */ newcookie = entry->cookie = next_cookie++; - list_add_tail(&entry->list, &async_pending); - if (running->registered && running->count++ == 0) - list_add_tail(&running->node, &async_domains); + + list_add_tail(&entry->domain_list, &domain->pending); + if (domain->registered) + list_add_tail(&entry->global_list, &async_global_pending); + atomic_inc(&entry_count); spin_unlock_irqrestore(&async_lock, flags); @@ -220,34 +198,34 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct a /** * async_schedule - schedule a function for asynchronous execution - * @ptr: function to execute asynchronously + * @func: function to execute asynchronously * @data: data pointer to pass to the function * * Returns an async_cookie_t that may be used for checkpointing later. * Note: This function may be called from atomic or non-atomic contexts. */ -async_cookie_t async_schedule(async_func_ptr *ptr, void *data) +async_cookie_t async_schedule(async_func_t func, void *data) { - return __async_schedule(ptr, data, &async_running); + return __async_schedule(func, data, &async_dfl_domain); } EXPORT_SYMBOL_GPL(async_schedule); /** * async_schedule_domain - schedule a function for asynchronous execution within a certain domain - * @ptr: function to execute asynchronously + * @func: function to execute asynchronously * @data: data pointer to pass to the function - * @running: running list for the domain + * @domain: the domain * * Returns an async_cookie_t that may be used for checkpointing later. - * @running may be used in the async_synchronize_*_domain() functions - * to wait within a certain synchronization domain rather than globally. - * A synchronization domain is specified via the running queue @running to use. - * Note: This function may be called from atomic or non-atomic contexts. + * @domain may be used in the async_synchronize_*_domain() functions to + * wait within a certain synchronization domain rather than globally. A + * synchronization domain is specified via @domain. Note: This function + * may be called from atomic or non-atomic contexts. */ -async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data, - struct async_domain *running) +async_cookie_t async_schedule_domain(async_func_t func, void *data, + struct async_domain *domain) { - return __async_schedule(ptr, data, running); + return __async_schedule(func, data, domain); } EXPORT_SYMBOL_GPL(async_schedule_domain); @@ -258,18 +236,7 @@ EXPORT_SYMBOL_GPL(async_schedule_domain); */ void async_synchronize_full(void) { - mutex_lock(&async_register_mutex); - do { - struct async_domain *domain = NULL; - - spin_lock_irq(&async_lock); - if (!list_empty(&async_domains)) - domain = list_first_entry(&async_domains, typeof(*domain), node); - spin_unlock_irq(&async_lock); - - async_synchronize_cookie_domain(next_cookie, domain); - } while (!list_empty(&async_domains)); - mutex_unlock(&async_register_mutex); + async_synchronize_full_domain(NULL); } EXPORT_SYMBOL_GPL(async_synchronize_full); @@ -284,51 +251,45 @@ EXPORT_SYMBOL_GPL(async_synchronize_full); */ void async_unregister_domain(struct async_domain *domain) { - mutex_lock(&async_register_mutex); spin_lock_irq(&async_lock); - WARN_ON(!domain->registered || !list_empty(&domain->node) || - !list_empty(&domain->domain)); + WARN_ON(!domain->registered || !list_empty(&domain->pending)); domain->registered = 0; spin_unlock_irq(&async_lock); - mutex_unlock(&async_register_mutex); } EXPORT_SYMBOL_GPL(async_unregister_domain); /** * async_synchronize_full_domain - synchronize all asynchronous function within a certain domain - * @domain: running list to synchronize on + * @domain: the domain to synchronize * * This function waits until all asynchronous function calls for the - * synchronization domain specified by the running list @domain have been done. + * synchronization domain specified by @domain have been done. */ void async_synchronize_full_domain(struct async_domain *domain) { - async_synchronize_cookie_domain(next_cookie, domain); + async_synchronize_cookie_domain(ASYNC_COOKIE_MAX, domain); } EXPORT_SYMBOL_GPL(async_synchronize_full_domain); /** * async_synchronize_cookie_domain - synchronize asynchronous function calls within a certain domain with cookie checkpointing * @cookie: async_cookie_t to use as checkpoint - * @running: running list to synchronize on + * @domain: the domain to synchronize (%NULL for all registered domains) * * This function waits until all asynchronous function calls for the - * synchronization domain specified by running list @running submitted - * prior to @cookie have been done. + * synchronization domain specified by @domain submitted prior to @cookie + * have been done. */ -void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain *running) +void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain *domain) { ktime_t uninitialized_var(starttime), delta, endtime; - if (!running) - return; - if (initcall_debug && system_state == SYSTEM_BOOTING) { printk(KERN_DEBUG "async_waiting @ %i\n", task_pid_nr(current)); starttime = ktime_get(); } - wait_event(async_done, lowest_in_progress(running) >= cookie); + wait_event(async_done, lowest_in_progress(domain) >= cookie); if (initcall_debug && system_state == SYSTEM_BOOTING) { endtime = ktime_get(); @@ -350,6 +311,18 @@ EXPORT_SYMBOL_GPL(async_synchronize_cookie_domain); */ void async_synchronize_cookie(async_cookie_t cookie) { - async_synchronize_cookie_domain(cookie, &async_running); + async_synchronize_cookie_domain(cookie, &async_dfl_domain); } EXPORT_SYMBOL_GPL(async_synchronize_cookie); + +/** + * current_is_async - is %current an async worker task? + * + * Returns %true if %current is an async worker task. + */ +bool current_is_async(void) +{ + struct worker *worker = current_wq_worker(); + + return worker && worker->current_func == async_run_entry_fn; +} diff --git a/kernel/audit.c b/kernel/audit.c index 5c7e62ff4795..21c7fa615bd3 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -60,7 +60,7 @@ #ifdef CONFIG_SECURITY #include <linux/security.h> #endif -#include <linux/netlink.h> +#include <net/netlink.h> #include <linux/freezer.h> #include <linux/tty.h> #include <linux/pid_namespace.h> @@ -646,14 +646,14 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) /* As soon as there's any sign of userspace auditd, * start kauditd to talk to it */ - if (!kauditd_task) + if (!kauditd_task) { kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); - if (IS_ERR(kauditd_task)) { - err = PTR_ERR(kauditd_task); - kauditd_task = NULL; - return err; + if (IS_ERR(kauditd_task)) { + err = PTR_ERR(kauditd_task); + kauditd_task = NULL; + return err; + } } - seq = nlh->nlmsg_seq; data = nlmsg_data(nlh); @@ -859,7 +859,7 @@ static void audit_receive_skb(struct sk_buff *skb) { struct nlmsghdr *nlh; /* - * len MUST be signed for NLMSG_NEXT to be able to dec it below 0 + * len MUST be signed for nlmsg_next to be able to dec it below 0 * if the nlmsg_len was not aligned */ int len; @@ -868,13 +868,13 @@ static void audit_receive_skb(struct sk_buff *skb) nlh = nlmsg_hdr(skb); len = skb->len; - while (NLMSG_OK(nlh, len)) { + while (nlmsg_ok(nlh, len)) { err = audit_receive_msg(skb, nlh); /* if err or if this message says it wants a response */ if (err || (nlh->nlmsg_flags & NLM_F_ACK)) netlink_ack(skb, nlh, err); - nlh = NLMSG_NEXT(nlh, len); + nlh = nlmsg_next(nlh, &len); } } @@ -1667,7 +1667,7 @@ void audit_log_end(struct audit_buffer *ab) audit_log_lost("rate limit exceeded"); } else { struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); - nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0); + nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN; if (audit_pid) { skb_queue_tail(&audit_skb_queue, ab->skb); diff --git a/kernel/audit.h b/kernel/audit.h index 45c8325de5bb..1c95131ef760 100644 --- a/kernel/audit.h +++ b/kernel/audit.h @@ -205,8 +205,6 @@ struct audit_context { #endif }; -#ifdef CONFIG_AUDIT -extern int audit_enabled; extern int audit_ever_enabled; extern void audit_copy_inode(struct audit_names *name, @@ -218,7 +216,6 @@ extern void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name); extern void audit_log_name(struct audit_context *context, struct audit_names *n, struct path *path, int record_num, int *call_panic); -#endif extern int audit_pid; diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c index 642a89c4f3d6..a291aa23fb3f 100644 --- a/kernel/audit_tree.c +++ b/kernel/audit_tree.c @@ -617,9 +617,9 @@ void audit_trim_trees(void) } spin_unlock(&hash_lock); trim_marked(tree); - put_tree(tree); drop_collected_mounts(root_mnt); skip_it: + put_tree(tree); mutex_lock(&audit_filter_mutex); } list_del(&cursor); diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index bc6595fe952e..83a2970295d1 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -533,6 +533,10 @@ exit_nofree: return entry; exit_free: + if (entry->rule.watch) + audit_put_watch(entry->rule.watch); /* matches initial get */ + if (entry->rule.tree) + audit_put_tree(entry->rule.tree); /* that's the temporary one */ audit_free_rule(entry); return ERR_PTR(err); } diff --git a/kernel/capability.c b/kernel/capability.c index 493d97259484..f6c2ce5701e1 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -393,6 +393,30 @@ bool ns_capable(struct user_namespace *ns, int cap) EXPORT_SYMBOL(ns_capable); /** + * file_ns_capable - Determine if the file's opener had a capability in effect + * @file: The file we want to check + * @ns: The usernamespace we want the capability in + * @cap: The capability to be tested for + * + * Return true if task that opened the file had a capability in effect + * when the file was opened. + * + * This does not set PF_SUPERPRIV because the caller may not + * actually be privileged. + */ +bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap) +{ + if (WARN_ON_ONCE(!cap_valid(cap))) + return false; + + if (security_capable(file->f_cred, ns, cap) == 0) + return true; + + return false; +} +EXPORT_SYMBOL(file_ns_capable); + +/** * capable - Determine if the current task has a superior capability in effect * @cap: The capability to be tested for * diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 4855892798fd..2a9926275f80 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -30,7 +30,6 @@ #include <linux/cred.h> #include <linux/ctype.h> #include <linux/errno.h> -#include <linux/fs.h> #include <linux/init_task.h> #include <linux/kernel.h> #include <linux/list.h> @@ -52,14 +51,14 @@ #include <linux/module.h> #include <linux/delayacct.h> #include <linux/cgroupstats.h> -#include <linux/hash.h> +#include <linux/hashtable.h> #include <linux/namei.h> #include <linux/pid_namespace.h> #include <linux/idr.h> #include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */ #include <linux/eventfd.h> #include <linux/poll.h> -#include <linux/flex_array.h> /* used in cgroup_attach_proc */ +#include <linux/flex_array.h> /* used in cgroup_attach_task */ #include <linux/kthread.h> #include <linux/atomic.h> @@ -83,7 +82,13 @@ * B happens only through cgroup_show_options() and using cgroup_root_mutex * breaks it. */ +#ifdef CONFIG_PROVE_RCU +DEFINE_MUTEX(cgroup_mutex); +EXPORT_SYMBOL_GPL(cgroup_mutex); /* only for task_subsys_state_check() */ +#else static DEFINE_MUTEX(cgroup_mutex); +#endif + static DEFINE_MUTEX(cgroup_root_mutex); /* @@ -98,56 +103,6 @@ static struct cgroup_subsys *subsys[CGROUP_SUBSYS_COUNT] = { #include <linux/cgroup_subsys.h> }; -#define MAX_CGROUP_ROOT_NAMELEN 64 - -/* - * A cgroupfs_root represents the root of a cgroup hierarchy, - * and may be associated with a superblock to form an active - * hierarchy - */ -struct cgroupfs_root { - struct super_block *sb; - - /* - * The bitmask of subsystems intended to be attached to this - * hierarchy - */ - unsigned long subsys_mask; - - /* Unique id for this hierarchy. */ - int hierarchy_id; - - /* The bitmask of subsystems currently attached to this hierarchy */ - unsigned long actual_subsys_mask; - - /* A list running through the attached subsystems */ - struct list_head subsys_list; - - /* The root cgroup for this hierarchy */ - struct cgroup top_cgroup; - - /* Tracks how many cgroups are currently defined in hierarchy.*/ - int number_of_cgroups; - - /* A list running through the active hierarchies */ - struct list_head root_list; - - /* All cgroups on this root, cgroup_mutex protected */ - struct list_head allcg_list; - - /* Hierarchy-specific flags */ - unsigned long flags; - - /* IDs for cgroups in this hierarchy */ - struct ida cgroup_ida; - - /* The path to use for release notifications. */ - char release_agent_path[PATH_MAX]; - - /* The name for this hierarchy - may be empty */ - char name[MAX_CGROUP_ROOT_NAMELEN]; -}; - /* * The "rootnode" hierarchy is the "dummy hierarchy", reserved for the * subsystems that are otherwise unattached - it never has more than a @@ -162,6 +117,9 @@ struct cfent { struct list_head node; struct dentry *dentry; struct cftype *type; + + /* file xattrs */ + struct simple_xattrs xattrs; }; /* @@ -238,6 +196,8 @@ static DEFINE_SPINLOCK(hierarchy_id_lock); /* dummytop is a shorthand for the dummy hierarchy's top cgroup */ #define dummytop (&rootnode.top_cgroup) +static struct cgroup_name root_cgroup_name = { .name = "/" }; + /* This flag indicates whether tasks in the fork and exit paths should * check for fork/exit handlers to call. This avoids us having to do * extra work in the fork/exit path if none of the subsystems need to @@ -249,20 +209,6 @@ static int cgroup_destroy_locked(struct cgroup *cgrp); static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys, struct cftype cfts[], bool is_add); -#ifdef CONFIG_PROVE_LOCKING -int cgroup_lock_is_held(void) -{ - return lockdep_is_held(&cgroup_mutex); -} -#else /* #ifdef CONFIG_PROVE_LOCKING */ -int cgroup_lock_is_held(void) -{ - return mutex_is_locked(&cgroup_mutex); -} -#endif /* #else #ifdef CONFIG_PROVE_LOCKING */ - -EXPORT_SYMBOL_GPL(cgroup_lock_is_held); - static int css_unbias_refcnt(int refcnt) { return refcnt >= 0 ? refcnt : refcnt - CSS_DEACT_BIAS; @@ -282,11 +228,25 @@ inline int cgroup_is_removed(const struct cgroup *cgrp) return test_bit(CGRP_REMOVED, &cgrp->flags); } -/* bits in struct cgroupfs_root flags field */ -enum { - ROOT_NOPREFIX, /* mounted subsystems have no named prefix */ - ROOT_XATTR, /* supports extended attributes */ -}; +/** + * cgroup_is_descendant - test ancestry + * @cgrp: the cgroup to be tested + * @ancestor: possible ancestor of @cgrp + * + * Test whether @cgrp is a descendant of @ancestor. It also returns %true + * if @cgrp == @ancestor. This function is safe to call as long as @cgrp + * and @ancestor are accessible. + */ +bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor) +{ + while (cgrp) { + if (cgrp == ancestor) + return true; + cgrp = cgrp->parent; + } + return false; +} +EXPORT_SYMBOL_GPL(cgroup_is_descendant); static int cgroup_is_releasable(const struct cgroup *cgrp) { @@ -327,6 +287,23 @@ static inline struct cftype *__d_cft(struct dentry *dentry) return __d_cfe(dentry)->type; } +/** + * cgroup_lock_live_group - take cgroup_mutex and check that cgrp is alive. + * @cgrp: the cgroup to be checked for liveness + * + * On success, returns true; the mutex should be later unlocked. On + * failure returns false with no lock held. + */ +static bool cgroup_lock_live_group(struct cgroup *cgrp) +{ + mutex_lock(&cgroup_mutex); + if (cgroup_is_removed(cgrp)) { + mutex_unlock(&cgroup_mutex); + return false; + } + return true; +} + /* the list of cgroups eligible for automatic release. Protected by * release_list_lock */ static LIST_HEAD(release_list); @@ -376,22 +353,18 @@ static int css_set_count; * account cgroups in empty hierarchies. */ #define CSS_SET_HASH_BITS 7 -#define CSS_SET_TABLE_SIZE (1 << CSS_SET_HASH_BITS) -static struct hlist_head css_set_table[CSS_SET_TABLE_SIZE]; +static DEFINE_HASHTABLE(css_set_table, CSS_SET_HASH_BITS); -static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[]) +static unsigned long css_set_hash(struct cgroup_subsys_state *css[]) { int i; - int index; - unsigned long tmp = 0UL; + unsigned long key = 0UL; for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) - tmp += (unsigned long)css[i]; - tmp = (tmp >> 16) ^ tmp; + key += (unsigned long)css[i]; + key = (key >> 16) ^ key; - index = hash_long(tmp, CSS_SET_HASH_BITS); - - return &css_set_table[index]; + return key; } /* We don't maintain the lists running through each css_set to its @@ -418,7 +391,7 @@ static void __put_css_set(struct css_set *cg, int taskexit) } /* This css_set is dead. unlink it and release cgroup refcounts */ - hlist_del(&cg->hlist); + hash_del(&cg->hlist); css_set_count--; list_for_each_entry_safe(link, saved_link, &cg->cg_links, @@ -426,12 +399,20 @@ static void __put_css_set(struct css_set *cg, int taskexit) struct cgroup *cgrp = link->cgrp; list_del(&link->cg_link_list); list_del(&link->cgrp_link_list); + + /* + * We may not be holding cgroup_mutex, and if cgrp->count is + * dropped to 0 the cgroup can be destroyed at any time, hence + * rcu_read_lock is used to keep it alive. + */ + rcu_read_lock(); if (atomic_dec_and_test(&cgrp->count) && notify_on_release(cgrp)) { if (taskexit) set_bit(CGRP_RELEASABLE, &cgrp->flags); check_for_release(cgrp); } + rcu_read_unlock(); kfree(link); } @@ -550,9 +531,8 @@ static struct css_set *find_existing_css_set( { int i; struct cgroupfs_root *root = cgrp->root; - struct hlist_head *hhead; - struct hlist_node *node; struct css_set *cg; + unsigned long key; /* * Build the set of subsystem state objects that we want to see in the @@ -572,8 +552,8 @@ static struct css_set *find_existing_css_set( } } - hhead = css_set_hash(template); - hlist_for_each_entry(cg, node, hhead, hlist) { + key = css_set_hash(template); + hash_for_each_possible(css_set_table, cg, hlist, key) { if (!compare_css_sets(cg, oldcg, cgrp, template)) continue; @@ -657,8 +637,8 @@ static struct css_set *find_css_set( struct list_head tmp_cg_links; - struct hlist_head *hhead; struct cg_cgroup_link *link; + unsigned long key; /* First see if we already have a cgroup group that matches * the desired set */ @@ -704,8 +684,8 @@ static struct css_set *find_css_set( css_set_count++; /* Add this cgroup group to the hash table */ - hhead = css_set_hash(res->subsys); - hlist_add_head(&res->hlist, hhead); + key = css_set_hash(res->subsys); + hash_add(css_set_table, &res->hlist, key); write_unlock(&css_set_lock); @@ -797,27 +777,6 @@ static struct cgroup *task_cgroup_from_root(struct task_struct *task, * update of a tasks cgroup pointer by cgroup_attach_task() */ -/** - * cgroup_lock - lock out any changes to cgroup structures - * - */ -void cgroup_lock(void) -{ - mutex_lock(&cgroup_mutex); -} -EXPORT_SYMBOL_GPL(cgroup_lock); - -/** - * cgroup_unlock - release lock on cgroup changes - * - * Undo the lock taken in a previous cgroup_lock() call. - */ -void cgroup_unlock(void) -{ - mutex_unlock(&cgroup_mutex); -} -EXPORT_SYMBOL_GPL(cgroup_unlock); - /* * A couple of forward declarations required, due to cyclic reference loop: * cgroup_mkdir -> cgroup_create -> cgroup_populate_dir -> @@ -856,57 +815,84 @@ static struct inode *cgroup_new_inode(umode_t mode, struct super_block *sb) return inode; } -static void cgroup_diput(struct dentry *dentry, struct inode *inode) +static struct cgroup_name *cgroup_alloc_name(struct dentry *dentry) { - /* is dentry a directory ? if so, kfree() associated cgroup */ - if (S_ISDIR(inode->i_mode)) { - struct cgroup *cgrp = dentry->d_fsdata; - struct cgroup_subsys *ss; - BUG_ON(!(cgroup_is_removed(cgrp))); - /* It's possible for external users to be holding css - * reference counts on a cgroup; css_put() needs to - * be able to access the cgroup after decrementing - * the reference count in order to know if it needs to - * queue the cgroup to be handled by the release - * agent */ - synchronize_rcu(); + struct cgroup_name *name; - mutex_lock(&cgroup_mutex); - /* - * Release the subsystem state objects. - */ - for_each_subsys(cgrp->root, ss) - ss->css_free(cgrp); + name = kmalloc(sizeof(*name) + dentry->d_name.len + 1, GFP_KERNEL); + if (!name) + return NULL; + strcpy(name->name, dentry->d_name.name); + return name; +} - cgrp->root->number_of_cgroups--; - mutex_unlock(&cgroup_mutex); +static void cgroup_free_fn(struct work_struct *work) +{ + struct cgroup *cgrp = container_of(work, struct cgroup, free_work); + struct cgroup_subsys *ss; - /* - * Drop the active superblock reference that we took when we - * created the cgroup - */ - deactivate_super(cgrp->root->sb); + mutex_lock(&cgroup_mutex); + /* + * Release the subsystem state objects. + */ + for_each_subsys(cgrp->root, ss) + ss->css_free(cgrp); - /* - * if we're getting rid of the cgroup, refcount should ensure - * that there are no pidlists left. - */ - BUG_ON(!list_empty(&cgrp->pidlists)); + cgrp->root->number_of_cgroups--; + mutex_unlock(&cgroup_mutex); + + /* + * We get a ref to the parent's dentry, and put the ref when + * this cgroup is being freed, so it's guaranteed that the + * parent won't be destroyed before its children. + */ + dput(cgrp->parent->dentry); + + ida_simple_remove(&cgrp->root->cgroup_ida, cgrp->id); + + /* + * Drop the active superblock reference that we took when we + * created the cgroup. This will free cgrp->root, if we are + * holding the last reference to @sb. + */ + deactivate_super(cgrp->root->sb); + + /* + * if we're getting rid of the cgroup, refcount should ensure + * that there are no pidlists left. + */ + BUG_ON(!list_empty(&cgrp->pidlists)); + + simple_xattrs_free(&cgrp->xattrs); - simple_xattrs_free(&cgrp->xattrs); + kfree(rcu_dereference_raw(cgrp->name)); + kfree(cgrp); +} + +static void cgroup_free_rcu(struct rcu_head *head) +{ + struct cgroup *cgrp = container_of(head, struct cgroup, rcu_head); + + schedule_work(&cgrp->free_work); +} + +static void cgroup_diput(struct dentry *dentry, struct inode *inode) +{ + /* is dentry a directory ? if so, kfree() associated cgroup */ + if (S_ISDIR(inode->i_mode)) { + struct cgroup *cgrp = dentry->d_fsdata; - ida_simple_remove(&cgrp->root->cgroup_ida, cgrp->id); - kfree_rcu(cgrp, rcu_head); + BUG_ON(!(cgroup_is_removed(cgrp))); + call_rcu(&cgrp->rcu_head, cgroup_free_rcu); } else { struct cfent *cfe = __d_cfe(dentry); struct cgroup *cgrp = dentry->d_parent->d_fsdata; - struct cftype *cft = cfe->type; WARN_ONCE(!list_empty(&cfe->node) && cgrp != &cgrp->root->top_cgroup, "cfe still linked for %s\n", cfe->type->name); + simple_xattrs_free(&cfe->xattrs); kfree(cfe); - simple_xattrs_free(&cft->xattrs); } iput(inode); } @@ -925,13 +911,17 @@ static void remove_dir(struct dentry *d) dput(parent); } -static int cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft) +static void cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft) { struct cfent *cfe; lockdep_assert_held(&cgrp->dentry->d_inode->i_mutex); lockdep_assert_held(&cgroup_mutex); + /* + * If we're doing cleanup due to failure of cgroup_create(), + * the corresponding @cfe may not exist. + */ list_for_each_entry(cfe, &cgrp->files, node) { struct dentry *d = cfe->dentry; @@ -944,9 +934,8 @@ static int cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft) list_del_init(&cfe->node); dput(d); - return 0; + break; } - return -ENOENT; } /** @@ -1083,7 +1072,6 @@ static int rebind_subsystems(struct cgroupfs_root *root, } } root->subsys_mask = root->actual_subsys_mask = final_subsys_mask; - synchronize_rcu(); return 0; } @@ -1096,9 +1084,11 @@ static int cgroup_show_options(struct seq_file *seq, struct dentry *dentry) mutex_lock(&cgroup_root_mutex); for_each_subsys(root, ss) seq_printf(seq, ",%s", ss->name); - if (test_bit(ROOT_NOPREFIX, &root->flags)) + if (root->flags & CGRP_ROOT_SANE_BEHAVIOR) + seq_puts(seq, ",sane_behavior"); + if (root->flags & CGRP_ROOT_NOPREFIX) seq_puts(seq, ",noprefix"); - if (test_bit(ROOT_XATTR, &root->flags)) + if (root->flags & CGRP_ROOT_XATTR) seq_puts(seq, ",xattr"); if (strlen(root->release_agent_path)) seq_printf(seq, ",release_agent=%s", root->release_agent_path); @@ -1160,8 +1150,12 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) all_ss = true; continue; } + if (!strcmp(token, "__DEVEL__sane_behavior")) { + opts->flags |= CGRP_ROOT_SANE_BEHAVIOR; + continue; + } if (!strcmp(token, "noprefix")) { - set_bit(ROOT_NOPREFIX, &opts->flags); + opts->flags |= CGRP_ROOT_NOPREFIX; continue; } if (!strcmp(token, "clone_children")) { @@ -1169,7 +1163,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) continue; } if (!strcmp(token, "xattr")) { - set_bit(ROOT_XATTR, &opts->flags); + opts->flags |= CGRP_ROOT_XATTR; continue; } if (!strncmp(token, "release_agent=", 14)) { @@ -1247,13 +1241,26 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) /* Consistency checks */ + if (opts->flags & CGRP_ROOT_SANE_BEHAVIOR) { + pr_warning("cgroup: sane_behavior: this is still under development and its behaviors will change, proceed at your own risk\n"); + + if (opts->flags & CGRP_ROOT_NOPREFIX) { + pr_err("cgroup: sane_behavior: noprefix is not allowed\n"); + return -EINVAL; + } + + if (opts->cpuset_clone_children) { + pr_err("cgroup: sane_behavior: clone_children is not allowed\n"); + return -EINVAL; + } + } + /* * Option noprefix was introduced just for backward compatibility * with the old cpuset, so we allow noprefix only if mounting just * the cpuset subsystem. */ - if (test_bit(ROOT_NOPREFIX, &opts->flags) && - (opts->subsys_mask & mask)) + if ((opts->flags & CGRP_ROOT_NOPREFIX) && (opts->subsys_mask & mask)) return -EINVAL; @@ -1324,6 +1331,11 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) struct cgroup_sb_opts opts; unsigned long added_mask, removed_mask; + if (root->flags & CGRP_ROOT_SANE_BEHAVIOR) { + pr_err("cgroup: sane_behavior: remount is not allowed\n"); + return -EINVAL; + } + mutex_lock(&cgrp->dentry->d_inode->i_mutex); mutex_lock(&cgroup_mutex); mutex_lock(&cgroup_root_mutex); @@ -1393,6 +1405,7 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) INIT_LIST_HEAD(&cgrp->allcg_node); INIT_LIST_HEAD(&cgrp->release_list); INIT_LIST_HEAD(&cgrp->pidlists); + INIT_WORK(&cgrp->free_work, cgroup_free_fn); mutex_init(&cgrp->pidlist_mutex); INIT_LIST_HEAD(&cgrp->event_list); spin_lock_init(&cgrp->event_list_lock); @@ -1408,7 +1421,7 @@ static void init_cgroup_root(struct cgroupfs_root *root) INIT_LIST_HEAD(&root->allcg_list); root->number_of_cgroups = 1; cgrp->root = root; - cgrp->top_cgroup = cgrp; + cgrp->name = &root_cgroup_name; init_cgroup_housekeeping(cgrp); list_add_tail(&cgrp->allcg_node, &root->allcg_list); } @@ -1597,6 +1610,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, struct cgroupfs_root *existing_root; const struct cred *cred; int i; + struct css_set *cg; BUG_ON(sb->s_root != NULL); @@ -1650,14 +1664,8 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, /* Link the top cgroup in this hierarchy into all * the css_set objects */ write_lock(&css_set_lock); - for (i = 0; i < CSS_SET_TABLE_SIZE; i++) { - struct hlist_head *hhead = &css_set_table[i]; - struct hlist_node *node; - struct css_set *cg; - - hlist_for_each_entry(cg, node, hhead, hlist) - link_css_set(&tmp_cg_links, cg, root_cgrp); - } + hash_for_each(css_set_table, i, cg, hlist) + link_css_set(&tmp_cg_links, cg, root_cgrp); write_unlock(&css_set_lock); free_cg_links(&tmp_cg_links); @@ -1677,6 +1685,14 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, * any) is not needed */ cgroup_drop_root(opts.new_root); + + if (((root->flags | opts.flags) & CGRP_ROOT_SANE_BEHAVIOR) && + root->flags != opts.flags) { + pr_err("cgroup: sane_behavior: new mount options should match the existing superblock\n"); + ret = -EINVAL; + goto drop_new_super; + } + /* no subsys rebinding, so refcounts don't change */ drop_parsed_module_refcounts(opts.subsys_mask); } @@ -1761,49 +1777,48 @@ static struct kobject *cgroup_kobj; * @buf: the buffer to write the path into * @buflen: the length of the buffer * - * Called with cgroup_mutex held or else with an RCU-protected cgroup - * reference. Writes path of cgroup into buf. Returns 0 on success, - * -errno on error. + * Writes path of cgroup into buf. Returns 0 on success, -errno on error. + * + * We can't generate cgroup path using dentry->d_name, as accessing + * dentry->name must be protected by irq-unsafe dentry->d_lock or parent + * inode's i_mutex, while on the other hand cgroup_path() can be called + * with some irq-safe spinlocks held. */ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen) { - struct dentry *dentry = cgrp->dentry; + int ret = -ENAMETOOLONG; char *start; - rcu_lockdep_assert(rcu_read_lock_held() || cgroup_lock_is_held(), - "cgroup_path() called without proper locking"); - - if (!dentry || cgrp == dummytop) { - /* - * Inactive subsystems have no dentry for their root - * cgroup - */ - strcpy(buf, "/"); + if (!cgrp->parent) { + if (strlcpy(buf, "/", buflen) >= buflen) + return -ENAMETOOLONG; return 0; } start = buf + buflen - 1; - *start = '\0'; - for (;;) { - int len = dentry->d_name.len; + rcu_read_lock(); + do { + const char *name = cgroup_name(cgrp); + int len; + + len = strlen(name); if ((start -= len) < buf) - return -ENAMETOOLONG; - memcpy(start, dentry->d_name.name, len); - cgrp = cgrp->parent; - if (!cgrp) - break; + goto out; + memcpy(start, name, len); - dentry = cgrp->dentry; - if (!cgrp->parent) - continue; if (--start < buf) - return -ENAMETOOLONG; + goto out; *start = '/'; - } + + cgrp = cgrp->parent; + } while (cgrp->parent); + ret = 0; memmove(buf, start, buf + buflen - start); - return 0; +out: + rcu_read_unlock(); + return ret; } EXPORT_SYMBOL_GPL(cgroup_path); @@ -1892,7 +1907,7 @@ EXPORT_SYMBOL_GPL(cgroup_taskset_size); * * Must be called with cgroup_mutex and threadgroup locked. */ -static void cgroup_task_migrate(struct cgroup *cgrp, struct cgroup *oldcgrp, +static void cgroup_task_migrate(struct cgroup *oldcgrp, struct task_struct *tsk, struct css_set *newcg) { struct css_set *oldcg; @@ -1925,122 +1940,22 @@ static void cgroup_task_migrate(struct cgroup *cgrp, struct cgroup *oldcgrp, } /** - * cgroup_attach_task - attach task 'tsk' to cgroup 'cgrp' - * @cgrp: the cgroup the task is attaching to - * @tsk: the task to be attached - * - * Call with cgroup_mutex and threadgroup locked. May take task_lock of - * @tsk during call. - */ -int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) -{ - int retval = 0; - struct cgroup_subsys *ss, *failed_ss = NULL; - struct cgroup *oldcgrp; - struct cgroupfs_root *root = cgrp->root; - struct cgroup_taskset tset = { }; - struct css_set *newcg; - - /* @tsk either already exited or can't exit until the end */ - if (tsk->flags & PF_EXITING) - return -ESRCH; - - /* Nothing to do if the task is already in that cgroup */ - oldcgrp = task_cgroup_from_root(tsk, root); - if (cgrp == oldcgrp) - return 0; - - tset.single.task = tsk; - tset.single.cgrp = oldcgrp; - - for_each_subsys(root, ss) { - if (ss->can_attach) { - retval = ss->can_attach(cgrp, &tset); - if (retval) { - /* - * Remember on which subsystem the can_attach() - * failed, so that we only call cancel_attach() - * against the subsystems whose can_attach() - * succeeded. (See below) - */ - failed_ss = ss; - goto out; - } - } - } - - newcg = find_css_set(tsk->cgroups, cgrp); - if (!newcg) { - retval = -ENOMEM; - goto out; - } - - cgroup_task_migrate(cgrp, oldcgrp, tsk, newcg); - - for_each_subsys(root, ss) { - if (ss->attach) - ss->attach(cgrp, &tset); - } - - synchronize_rcu(); -out: - if (retval) { - for_each_subsys(root, ss) { - if (ss == failed_ss) - /* - * This subsystem was the one that failed the - * can_attach() check earlier, so we don't need - * to call cancel_attach() against it or any - * remaining subsystems. - */ - break; - if (ss->cancel_attach) - ss->cancel_attach(cgrp, &tset); - } - } - return retval; -} - -/** - * cgroup_attach_task_all - attach task 'tsk' to all cgroups of task 'from' - * @from: attach to all cgroups of a given task - * @tsk: the task to be attached - */ -int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) -{ - struct cgroupfs_root *root; - int retval = 0; - - cgroup_lock(); - for_each_active_root(root) { - struct cgroup *from_cg = task_cgroup_from_root(from, root); - - retval = cgroup_attach_task(from_cg, tsk); - if (retval) - break; - } - cgroup_unlock(); - - return retval; -} -EXPORT_SYMBOL_GPL(cgroup_attach_task_all); - -/** - * cgroup_attach_proc - attach all threads in a threadgroup to a cgroup + * cgroup_attach_task - attach a task or a whole threadgroup to a cgroup * @cgrp: the cgroup to attach to - * @leader: the threadgroup leader task_struct of the group to be attached + * @tsk: the task or the leader of the threadgroup to be attached + * @threadgroup: attach the whole threadgroup? * * Call holding cgroup_mutex and the group_rwsem of the leader. Will take - * task_lock of each thread in leader's threadgroup individually in turn. + * task_lock of @tsk or each thread in the threadgroup individually in turn. */ -static int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) +static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk, + bool threadgroup) { int retval, i, group_size; struct cgroup_subsys *ss, *failed_ss = NULL; - /* guaranteed to be initialized later, but the compiler needs this */ struct cgroupfs_root *root = cgrp->root; /* threadgroup list cursor and array */ - struct task_struct *tsk; + struct task_struct *leader = tsk; struct task_and_cgroup *tc; struct flex_array *group; struct cgroup_taskset tset = { }; @@ -2052,17 +1967,19 @@ static int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) * group - group_rwsem prevents new threads from appearing, and if * threads exit, this will just be an over-estimate. */ - group_size = get_nr_threads(leader); + if (threadgroup) + group_size = get_nr_threads(tsk); + else + group_size = 1; /* flex_array supports very large thread-groups better than kmalloc. */ group = flex_array_alloc(sizeof(*tc), group_size, GFP_KERNEL); if (!group) return -ENOMEM; /* pre-allocate to guarantee space while iterating in rcu read-side. */ - retval = flex_array_prealloc(group, 0, group_size - 1, GFP_KERNEL); + retval = flex_array_prealloc(group, 0, group_size, GFP_KERNEL); if (retval) goto out_free_group_list; - tsk = leader; i = 0; /* * Prevent freeing of tasks while we take a snapshot. Tasks that are @@ -2091,6 +2008,9 @@ static int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) retval = flex_array_put(group, i, &ent, GFP_ATOMIC); BUG_ON(retval != 0); i++; + + if (!threadgroup) + break; } while_each_thread(leader, tsk); rcu_read_unlock(); /* remember the number of threads in the array for later. */ @@ -2136,7 +2056,7 @@ static int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) */ for (i = 0; i < group_size; i++) { tc = flex_array_get(group, i); - cgroup_task_migrate(cgrp, tc->cgrp, tc->task, tc->cg); + cgroup_task_migrate(tc->cgrp, tc->task, tc->cg); } /* nothing is sensitive to fork() after this point. */ @@ -2151,7 +2071,6 @@ static int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) /* * step 5: success! and cleanup */ - synchronize_rcu(); retval = 0; out_put_css_set_refs: if (retval) { @@ -2218,11 +2137,11 @@ retry_find_task: tsk = tsk->group_leader; /* - * Workqueue threads may acquire PF_THREAD_BOUND and become + * Workqueue threads may acquire PF_NO_SETAFFINITY and become * trapped in a cpuset, or RT worker may be born in a cgroup * with no rt_runtime allocated. Just say no. */ - if (tsk == kthreadd_task || (tsk->flags & PF_THREAD_BOUND)) { + if (tsk == kthreadd_task || (tsk->flags & PF_NO_SETAFFINITY)) { ret = -EINVAL; rcu_read_unlock(); goto out_unlock_cgroup; @@ -2245,17 +2164,42 @@ retry_find_task: put_task_struct(tsk); goto retry_find_task; } - ret = cgroup_attach_proc(cgrp, tsk); - } else - ret = cgroup_attach_task(cgrp, tsk); + } + + ret = cgroup_attach_task(cgrp, tsk, threadgroup); + threadgroup_unlock(tsk); put_task_struct(tsk); out_unlock_cgroup: - cgroup_unlock(); + mutex_unlock(&cgroup_mutex); return ret; } +/** + * cgroup_attach_task_all - attach task 'tsk' to all cgroups of task 'from' + * @from: attach to all cgroups of a given task + * @tsk: the task to be attached + */ +int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) +{ + struct cgroupfs_root *root; + int retval = 0; + + mutex_lock(&cgroup_mutex); + for_each_active_root(root) { + struct cgroup *from_cg = task_cgroup_from_root(from, root); + + retval = cgroup_attach_task(from_cg, tsk, false); + if (retval) + break; + } + mutex_unlock(&cgroup_mutex); + + return retval; +} +EXPORT_SYMBOL_GPL(cgroup_attach_task_all); + static int cgroup_tasks_write(struct cgroup *cgrp, struct cftype *cft, u64 pid) { return attach_task_by_pid(cgrp, pid, false); @@ -2266,24 +2210,6 @@ static int cgroup_procs_write(struct cgroup *cgrp, struct cftype *cft, u64 tgid) return attach_task_by_pid(cgrp, tgid, true); } -/** - * cgroup_lock_live_group - take cgroup_mutex and check that cgrp is alive. - * @cgrp: the cgroup to be checked for liveness - * - * On success, returns true; the lock should be later released with - * cgroup_unlock(). On failure returns false with no lock held. - */ -bool cgroup_lock_live_group(struct cgroup *cgrp) -{ - mutex_lock(&cgroup_mutex); - if (cgroup_is_removed(cgrp)) { - mutex_unlock(&cgroup_mutex); - return false; - } - return true; -} -EXPORT_SYMBOL_GPL(cgroup_lock_live_group); - static int cgroup_release_agent_write(struct cgroup *cgrp, struct cftype *cft, const char *buffer) { @@ -2295,7 +2221,7 @@ static int cgroup_release_agent_write(struct cgroup *cgrp, struct cftype *cft, mutex_lock(&cgroup_root_mutex); strcpy(cgrp->root->release_agent_path, buffer); mutex_unlock(&cgroup_root_mutex); - cgroup_unlock(); + mutex_unlock(&cgroup_mutex); return 0; } @@ -2306,7 +2232,14 @@ static int cgroup_release_agent_show(struct cgroup *cgrp, struct cftype *cft, return -ENODEV; seq_puts(seq, cgrp->root->release_agent_path); seq_putc(seq, '\n'); - cgroup_unlock(); + mutex_unlock(&cgroup_mutex); + return 0; +} + +static int cgroup_sane_behavior_show(struct cgroup *cgrp, struct cftype *cft, + struct seq_file *seq) +{ + seq_printf(seq, "%d\n", cgroup_sane_behavior(cgrp)); return 0; } @@ -2531,13 +2464,40 @@ static int cgroup_file_release(struct inode *inode, struct file *file) static int cgroup_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { + int ret; + struct cgroup_name *name, *old_name; + struct cgroup *cgrp; + + /* + * It's convinient to use parent dir's i_mutex to protected + * cgrp->name. + */ + lockdep_assert_held(&old_dir->i_mutex); + if (!S_ISDIR(old_dentry->d_inode->i_mode)) return -ENOTDIR; if (new_dentry->d_inode) return -EEXIST; if (old_dir != new_dir) return -EIO; - return simple_rename(old_dir, old_dentry, new_dir, new_dentry); + + cgrp = __d_cgrp(old_dentry); + + name = cgroup_alloc_name(new_dentry); + if (!name) + return -ENOMEM; + + ret = simple_rename(old_dir, old_dentry, new_dir, new_dentry); + if (ret) { + kfree(name); + return ret; + } + + old_name = cgrp->name; + rcu_assign_pointer(cgrp->name, name); + + kfree_rcu(old_name, rcu_head); + return 0; } static struct simple_xattrs *__d_xattrs(struct dentry *dentry) @@ -2545,13 +2505,13 @@ static struct simple_xattrs *__d_xattrs(struct dentry *dentry) if (S_ISDIR(dentry->d_inode->i_mode)) return &__d_cgrp(dentry)->xattrs; else - return &__d_cft(dentry)->xattrs; + return &__d_cfe(dentry)->xattrs; } static inline int xattr_enabled(struct dentry *dentry) { struct cgroupfs_root *root = dentry->d_sb->s_fs_info; - return test_bit(ROOT_XATTR, &root->flags); + return root->flags & CGRP_ROOT_XATTR; } static bool is_valid_xattr(const char *name) @@ -2637,7 +2597,7 @@ static struct dentry *cgroup_lookup(struct inode *dir, struct dentry *dentry, un */ static inline struct cftype *__file_cft(struct file *file) { - if (file->f_dentry->d_inode->i_fop != &cgroup_file_operations) + if (file_inode(file)->i_fop != &cgroup_file_operations) return ERR_PTR(-EINVAL); return __d_cft(file->f_dentry); } @@ -2721,9 +2681,7 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, umode_t mode; char name[MAX_CGROUP_TYPE_NAMELEN + MAX_CFTYPE_NAME + 2] = { 0 }; - simple_xattrs_init(&cft->xattrs); - - if (subsys && !test_bit(ROOT_NOPREFIX, &cgrp->root->flags)) { + if (subsys && !(cgrp->root->flags & CGRP_ROOT_NOPREFIX)) { strcpy(name, subsys->name); strcat(name, "."); } @@ -2747,6 +2705,7 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, cfe->type = (void *)cft; cfe->dentry = dentry; dentry->d_fsdata = cfe; + simple_xattrs_init(&cfe->xattrs); list_add_tail(&cfe->node, &parent->files); cfe = NULL; } @@ -2764,19 +2723,21 @@ static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys, for (cft = cfts; cft->name[0] != '\0'; cft++) { /* does cft->flags tell us to skip this file on @cgrp? */ + if ((cft->flags & CFTYPE_INSANE) && cgroup_sane_behavior(cgrp)) + continue; if ((cft->flags & CFTYPE_NOT_ON_ROOT) && !cgrp->parent) continue; if ((cft->flags & CFTYPE_ONLY_ON_ROOT) && cgrp->parent) continue; - if (is_add) + if (is_add) { err = cgroup_add_file(cgrp, subsys, cft); - else - err = cgroup_rm_file(cgrp, cft); - if (err) { - pr_warning("cgroup_addrm_files: failed to %s %s, err=%d\n", - is_add ? "add" : "remove", cft->name, err); + if (err) + pr_warn("cgroup_addrm_files: failed to add %s, err=%d\n", + cft->name, err); ret = err; + } else { + cgroup_rm_file(cgrp, cft); } } return ret; @@ -3017,6 +2978,32 @@ struct cgroup *cgroup_next_descendant_pre(struct cgroup *pos, } EXPORT_SYMBOL_GPL(cgroup_next_descendant_pre); +/** + * cgroup_rightmost_descendant - return the rightmost descendant of a cgroup + * @pos: cgroup of interest + * + * Return the rightmost descendant of @pos. If there's no descendant, + * @pos is returned. This can be used during pre-order traversal to skip + * subtree of @pos. + */ +struct cgroup *cgroup_rightmost_descendant(struct cgroup *pos) +{ + struct cgroup *last, *tmp; + + WARN_ON_ONCE(!rcu_read_lock_held()); + + do { + last = pos; + /* ->prev isn't RCU safe, walk ->next till the end */ + pos = NULL; + list_for_each_entry_rcu(tmp, &last->children, sibling) + pos = tmp; + } while (pos); + + return last; +} +EXPORT_SYMBOL_GPL(cgroup_rightmost_descendant); + static struct cgroup *cgroup_leftmost_descendant(struct cgroup *pos) { struct cgroup *last; @@ -3268,6 +3255,34 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan) return 0; } +static void cgroup_transfer_one_task(struct task_struct *task, + struct cgroup_scanner *scan) +{ + struct cgroup *new_cgroup = scan->data; + + mutex_lock(&cgroup_mutex); + cgroup_attach_task(new_cgroup, task, false); + mutex_unlock(&cgroup_mutex); +} + +/** + * cgroup_trasnsfer_tasks - move tasks from one cgroup to another + * @to: cgroup to which the tasks will be moved + * @from: cgroup in which the tasks currently reside + */ +int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) +{ + struct cgroup_scanner scan; + + scan.cg = from; + scan.test_task = NULL; /* select all tasks in cgroup */ + scan.process_task = cgroup_transfer_one_task; + scan.heap = NULL; + scan.data = to; + + return cgroup_scan_tasks(&scan); +} + /* * Stuff for reading the 'tasks'/'procs' files. * @@ -3330,35 +3345,14 @@ static void pidlist_free(void *p) else kfree(p); } -static void *pidlist_resize(void *p, int newcount) -{ - void *newlist; - /* note: if new alloc fails, old p will still be valid either way */ - if (is_vmalloc_addr(p)) { - newlist = vmalloc(newcount * sizeof(pid_t)); - if (!newlist) - return NULL; - memcpy(newlist, p, newcount * sizeof(pid_t)); - vfree(p); - } else { - newlist = krealloc(p, newcount * sizeof(pid_t), GFP_KERNEL); - } - return newlist; -} /* * pidlist_uniq - given a kmalloc()ed list, strip out all duplicate entries - * If the new stripped list is sufficiently smaller and there's enough memory - * to allocate a new buffer, will let go of the unneeded memory. Returns the - * number of unique elements. + * Returns the number of unique elements. */ -/* is the size difference enough that we should re-allocate the array? */ -#define PIDLIST_REALLOC_DIFFERENCE(old, new) ((old) - PAGE_SIZE >= (new)) -static int pidlist_uniq(pid_t **p, int length) +static int pidlist_uniq(pid_t *list, int length) { int src, dest = 1; - pid_t *list = *p; - pid_t *newlist; /* * we presume the 0th element is unique, so i starts at 1. trivial @@ -3379,16 +3373,6 @@ static int pidlist_uniq(pid_t **p, int length) dest++; } after: - /* - * if the length difference is large enough, we want to allocate a - * smaller buffer to save memory. if this fails due to out of memory, - * we'll just stay with what we've got. - */ - if (PIDLIST_REALLOC_DIFFERENCE(length, dest)) { - newlist = pidlist_resize(list, dest); - if (newlist) - *p = newlist; - } return dest; } @@ -3484,7 +3468,7 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type, /* now sort & (if procs) strip out duplicates */ sort(array, length, sizeof(pid_t), cmppid, NULL); if (type == CGROUP_FILE_PROCS) - length = pidlist_uniq(&array, length); + length = pidlist_uniq(array, length); l = cgroup_pidlist_find(cgrp, type); if (!l) { pidlist_free(array); @@ -3752,8 +3736,13 @@ static void cgroup_event_remove(struct work_struct *work) remove); struct cgroup *cgrp = event->cgrp; + remove_wait_queue(event->wqh, &event->wait); + event->cft->unregister_event(cgrp, event->cft, event->eventfd); + /* Notify userspace the event is going away. */ + eventfd_signal(event->eventfd, 1); + eventfd_ctx_put(event->eventfd); kfree(event); dput(cgrp->dentry); @@ -3773,15 +3762,25 @@ static int cgroup_event_wake(wait_queue_t *wait, unsigned mode, unsigned long flags = (unsigned long)key; if (flags & POLLHUP) { - __remove_wait_queue(event->wqh, &event->wait); - spin_lock(&cgrp->event_list_lock); - list_del_init(&event->list); - spin_unlock(&cgrp->event_list_lock); /* - * We are in atomic context, but cgroup_event_remove() may - * sleep, so we have to call it in workqueue. + * If the event has been detached at cgroup removal, we + * can simply return knowing the other side will cleanup + * for us. + * + * We can't race against event freeing since the other + * side will require wqh->lock via remove_wait_queue(), + * which we hold. */ - schedule_work(&event->remove); + spin_lock(&cgrp->event_list_lock); + if (!list_empty(&event->list)) { + list_del_init(&event->list); + /* + * We are in atomic context, but cgroup_event_remove() + * may sleep, so we have to call it in workqueue. + */ + schedule_work(&event->remove); + } + spin_unlock(&cgrp->event_list_lock); } return 0; @@ -3807,6 +3806,7 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft, const char *buffer) { struct cgroup_event *event = NULL; + struct cgroup *cgrp_cfile; unsigned int efd, cfd; struct file *efile = NULL; struct file *cfile = NULL; @@ -3852,7 +3852,7 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft, /* the process need read permission on control file */ /* AV: shouldn't we check that it's been opened for read instead? */ - ret = inode_permission(cfile->f_path.dentry->d_inode, MAY_READ); + ret = inode_permission(file_inode(cfile), MAY_READ); if (ret < 0) goto fail; @@ -3862,6 +3862,16 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft, goto fail; } + /* + * The file to be monitored must be in the same cgroup as + * cgroup.event_control is. + */ + cgrp_cfile = __d_cgrp(cfile->f_dentry->d_parent); + if (cgrp_cfile != cgrp) { + ret = -EINVAL; + goto fail; + } + if (!event->cft->register_event || !event->cft->unregister_event) { ret = -EINVAL; goto fail; @@ -3872,11 +3882,7 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft, if (ret) goto fail; - if (efile->f_op->poll(efile, &event->pt) & POLLHUP) { - event->cft->unregister_event(cgrp, event->cft, event->eventfd); - ret = 0; - goto fail; - } + efile->f_op->poll(efile, &event->pt); /* * Events should be removed after rmdir of cgroup directory, but before @@ -3958,10 +3964,16 @@ static struct cftype files[] = { }, { .name = "cgroup.clone_children", + .flags = CFTYPE_INSANE, .read_u64 = cgroup_clone_children_read, .write_u64 = cgroup_clone_children_write, }, { + .name = "cgroup.sane_behavior", + .flags = CFTYPE_ONLY_ON_ROOT, + .read_seq_string = cgroup_sane_behavior_show, + }, + { .name = "release_agent", .flags = CFTYPE_ONLY_ON_ROOT, .read_seq_string = cgroup_release_agent_show, @@ -4073,17 +4085,8 @@ static void offline_css(struct cgroup_subsys *ss, struct cgroup *cgrp) if (!(css->flags & CSS_ONLINE)) return; - /* - * css_offline() should be called with cgroup_mutex unlocked. See - * 3fa59dfbc3 ("cgroup: fix potential deadlock in pre_destroy") for - * details. This temporary unlocking should go away once - * cgroup_mutex is unexported from controllers. - */ - if (ss->css_offline) { - mutex_unlock(&cgroup_mutex); + if (ss->css_offline) ss->css_offline(cgrp); - mutex_lock(&cgroup_mutex); - } cgrp->subsys[ss->subsys_id]->flags &= ~CSS_ONLINE; } @@ -4100,6 +4103,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, umode_t mode) { struct cgroup *cgrp; + struct cgroup_name *name; struct cgroupfs_root *root = parent->root; int err = 0; struct cgroup_subsys *ss; @@ -4110,9 +4114,14 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, if (!cgrp) return -ENOMEM; + name = cgroup_alloc_name(dentry); + if (!name) + goto err_free_cgrp; + rcu_assign_pointer(cgrp->name, name); + cgrp->id = ida_simple_get(&root->cgroup_ida, 1, 0, GFP_KERNEL); if (cgrp->id < 0) - goto err_free_cgrp; + goto err_free_name; /* * Only live parents can have children. Note that the liveliness @@ -4135,9 +4144,11 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, init_cgroup_housekeeping(cgrp); + dentry->d_fsdata = cgrp; + cgrp->dentry = dentry; + cgrp->parent = parent; cgrp->root = parent->root; - cgrp->top_cgroup = parent->top_cgroup; if (notify_on_release(parent)) set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); @@ -4172,8 +4183,6 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, lockdep_assert_held(&dentry->d_inode->i_mutex); /* allocation complete, commit to creation */ - dentry->d_fsdata = cgrp; - cgrp->dentry = dentry; list_add_tail(&cgrp->allcg_node, &root->allcg_list); list_add_tail_rcu(&cgrp->sibling, &cgrp->parent->children); root->number_of_cgroups++; @@ -4182,6 +4191,9 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, for_each_subsys(root, ss) dget(dentry); + /* hold a ref to the parent's dentry */ + dget(parent->dentry); + /* creation succeeded, notify subsystems */ for_each_subsys(root, ss) { err = online_css(ss, cgrp); @@ -4217,6 +4229,8 @@ err_free_all: deactivate_super(sb); err_free_id: ida_simple_remove(&root->cgroup_ida, cgrp->id); +err_free_name: + kfree(rcu_dereference_raw(cgrp->name)); err_free_cgrp: kfree(cgrp); return err; @@ -4236,56 +4250,13 @@ static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) return cgroup_create(c_parent, dentry, mode | S_IFDIR); } -/* - * Check the reference count on each subsystem. Since we already - * established that there are no tasks in the cgroup, if the css refcount - * is also 1, then there should be no outstanding references, so the - * subsystem is safe to destroy. We scan across all subsystems rather than - * using the per-hierarchy linked list of mounted subsystems since we can - * be called via check_for_release() with no synchronization other than - * RCU, and the subsystem linked list isn't RCU-safe. - */ -static int cgroup_has_css_refs(struct cgroup *cgrp) -{ - int i; - - /* - * We won't need to lock the subsys array, because the subsystems - * we're concerned about aren't going anywhere since our cgroup root - * has a reference on them. - */ - for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { - struct cgroup_subsys *ss = subsys[i]; - struct cgroup_subsys_state *css; - - /* Skip subsystems not present or not in this hierarchy */ - if (ss == NULL || ss->root != cgrp->root) - continue; - - css = cgrp->subsys[ss->subsys_id]; - /* - * When called from check_for_release() it's possible - * that by this point the cgroup has been removed - * and the css deleted. But a false-positive doesn't - * matter, since it can only happen if the cgroup - * has been deleted and hence no longer needs the - * release agent to be called anyway. - */ - if (css && css_refcnt(css) > 1) - return 1; - } - return 0; -} - static int cgroup_destroy_locked(struct cgroup *cgrp) __releases(&cgroup_mutex) __acquires(&cgroup_mutex) { struct dentry *d = cgrp->dentry; struct cgroup *parent = cgrp->parent; - DEFINE_WAIT(wait); struct cgroup_event *event, *tmp; struct cgroup_subsys *ss; - LIST_HEAD(tmp_list); lockdep_assert_held(&d->d_inode->i_mutex); lockdep_assert_held(&cgroup_mutex); @@ -4340,20 +4311,14 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) /* * Unregister events and notify userspace. * Notify userspace about cgroup removing only after rmdir of cgroup - * directory to avoid race between userspace and kernelspace. Use - * a temporary list to avoid a deadlock with cgroup_event_wake(). Since - * cgroup_event_wake() is called with the wait queue head locked, - * remove_wait_queue() cannot be called while holding event_list_lock. + * directory to avoid race between userspace and kernelspace. */ spin_lock(&cgrp->event_list_lock); - list_splice_init(&cgrp->event_list, &tmp_list); - spin_unlock(&cgrp->event_list_lock); - list_for_each_entry_safe(event, tmp, &tmp_list, list) { + list_for_each_entry_safe(event, tmp, &cgrp->event_list, list) { list_del_init(&event->list); - remove_wait_queue(event->wqh, &event->wait); - eventfd_signal(event->eventfd, 1); schedule_work(&event->remove); } + spin_unlock(&cgrp->event_list_lock); return 0; } @@ -4415,7 +4380,6 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss) * need to invoke fork callbacks here. */ BUG_ON(!list_empty(&init_task.tasks)); - ss->active = 1; BUG_ON(online_css(ss, dummytop)); mutex_unlock(&cgroup_mutex); @@ -4438,6 +4402,9 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss) { struct cgroup_subsys_state *css; int i, ret; + struct hlist_node *tmp; + struct css_set *cg; + unsigned long key; /* check name and function validity */ if (ss->name == NULL || strlen(ss->name) > MAX_CGROUP_TYPE_NAMELEN || @@ -4503,27 +4470,20 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss) * this is all done under the css_set_lock. */ write_lock(&css_set_lock); - for (i = 0; i < CSS_SET_TABLE_SIZE; i++) { - struct css_set *cg; - struct hlist_node *node, *tmp; - struct hlist_head *bucket = &css_set_table[i], *new_bucket; - - hlist_for_each_entry_safe(cg, node, tmp, bucket, hlist) { - /* skip entries that we already rehashed */ - if (cg->subsys[ss->subsys_id]) - continue; - /* remove existing entry */ - hlist_del(&cg->hlist); - /* set new value */ - cg->subsys[ss->subsys_id] = css; - /* recompute hash and restore entry */ - new_bucket = css_set_hash(cg->subsys); - hlist_add_head(&cg->hlist, new_bucket); - } + hash_for_each_safe(css_set_table, i, tmp, cg, hlist) { + /* skip entries that we already rehashed */ + if (cg->subsys[ss->subsys_id]) + continue; + /* remove existing entry */ + hash_del(&cg->hlist); + /* set new value */ + cg->subsys[ss->subsys_id] = css; + /* recompute hash and restore entry */ + key = css_set_hash(cg->subsys); + hash_add(css_set_table, &cg->hlist, key); } write_unlock(&css_set_lock); - ss->active = 1; ret = online_css(ss, dummytop); if (ret) goto err_unload; @@ -4551,7 +4511,6 @@ EXPORT_SYMBOL_GPL(cgroup_load_subsys); void cgroup_unload_subsys(struct cgroup_subsys *ss) { struct cg_cgroup_link *link; - struct hlist_head *hhead; BUG_ON(ss->module == NULL); @@ -4565,12 +4524,9 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss) mutex_lock(&cgroup_mutex); offline_css(ss, dummytop); - ss->active = 0; - if (ss->use_id) { - idr_remove_all(&ss->idr); + if (ss->use_id) idr_destroy(&ss->idr); - } /* deassign the subsys_id */ subsys[ss->subsys_id] = NULL; @@ -4585,11 +4541,12 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss) write_lock(&css_set_lock); list_for_each_entry(link, &dummytop->css_sets, cgrp_link_list) { struct css_set *cg = link->cg; + unsigned long key; - hlist_del(&cg->hlist); + hash_del(&cg->hlist); cg->subsys[ss->subsys_id] = NULL; - hhead = css_set_hash(cg->subsys); - hlist_add_head(&cg->hlist, hhead); + key = css_set_hash(cg->subsys); + hash_add(css_set_table, &cg->hlist, key); } write_unlock(&css_set_lock); @@ -4631,9 +4588,6 @@ int __init cgroup_init_early(void) list_add(&init_css_set_link.cg_link_list, &init_css_set.cg_links); - for (i = 0; i < CSS_SET_TABLE_SIZE; i++) - INIT_HLIST_HEAD(&css_set_table[i]); - for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; @@ -4667,7 +4621,7 @@ int __init cgroup_init(void) { int err; int i; - struct hlist_head *hhead; + unsigned long key; err = bdi_init(&cgroup_backing_dev_info); if (err) @@ -4686,8 +4640,8 @@ int __init cgroup_init(void) } /* Add init_css_set to the hash table */ - hhead = css_set_hash(init_css_set.subsys); - hlist_add_head(&init_css_set.hlist, hhead); + key = css_set_hash(init_css_set.subsys); + hash_add(css_set_table, &init_css_set.hlist, key); BUG_ON(!init_root_id(&rootnode)); cgroup_kobj = kobject_create_and_add("cgroup", fs_kobj); @@ -4724,7 +4678,7 @@ out: */ /* TODO: Use a proper seq_file iterator */ -static int proc_cgroup_show(struct seq_file *m, void *v) +int proc_cgroup_show(struct seq_file *m, void *v) { struct pid *pid; struct task_struct *tsk; @@ -4776,19 +4730,6 @@ out: return retval; } -static int cgroup_open(struct inode *inode, struct file *file) -{ - struct pid *pid = PROC_I(inode)->pid; - return single_open(file, proc_cgroup_show, pid); -} - -const struct file_operations proc_cgroup_operations = { - .open = cgroup_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - /* Display information about each subsystem and each hierarchy */ static int proc_cgroupstats_show(struct seq_file *m, void *v) { @@ -4890,17 +4831,17 @@ void cgroup_post_fork(struct task_struct *child) * and addition to css_set. */ if (need_forkexit_callback) { - for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { + /* + * fork/exit callbacks are supported only for builtin + * subsystems, and the builtin section of the subsys + * array is immutable, so we don't need to lock the + * subsys array here. On the other hand, modular section + * of the array can be freed at module unload, so we + * can't touch that. + */ + for (i = 0; i < CGROUP_BUILTIN_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; - /* - * fork/exit callbacks are supported only for - * builtin subsystems and we don't need further - * synchronization as they never go away. - */ - if (!ss || ss->module) - continue; - if (ss->fork) ss->fork(child); } @@ -4965,13 +4906,13 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks) tsk->cgroups = &init_css_set; if (run_callbacks && need_forkexit_callback) { - for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { + /* + * fork/exit callbacks are supported only for builtin + * subsystems, see cgroup_post_fork() for details. + */ + for (i = 0; i < CGROUP_BUILTIN_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; - /* modular subsystems can't use callbacks */ - if (!ss || ss->module) - continue; - if (ss->exit) { struct cgroup *old_cgrp = rcu_dereference_raw(cg->subsys[i])->cgroup; @@ -4982,48 +4923,22 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks) } task_unlock(tsk); - if (cg) - put_css_set_taskexit(cg); -} - -/** - * cgroup_is_descendant - see if @cgrp is a descendant of @task's cgrp - * @cgrp: the cgroup in question - * @task: the task in question - * - * See if @cgrp is a descendant of @task's cgroup in the appropriate - * hierarchy. - * - * If we are sending in dummytop, then presumably we are creating - * the top cgroup in the subsystem. - * - * Called only by the ns (nsproxy) cgroup. - */ -int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task) -{ - int ret; - struct cgroup *target; - - if (cgrp == dummytop) - return 1; - - target = task_cgroup_from_root(task, cgrp->root); - while (cgrp != target && cgrp!= cgrp->top_cgroup) - cgrp = cgrp->parent; - ret = (cgrp == target); - return ret; + put_css_set_taskexit(cg); } static void check_for_release(struct cgroup *cgrp) { /* All of these checks rely on RCU to keep the cgroup * structure alive */ - if (cgroup_is_releasable(cgrp) && !atomic_read(&cgrp->count) - && list_empty(&cgrp->children) && !cgroup_has_css_refs(cgrp)) { - /* Control Group is currently removeable. If it's not + if (cgroup_is_releasable(cgrp) && + !atomic_read(&cgrp->count) && list_empty(&cgrp->children)) { + /* + * Control Group is currently removeable. If it's not * already queued for a userspace notification, queue - * it now */ + * it now + */ int need_schedule_work = 0; + raw_spin_lock(&release_list_lock); if (!cgroup_is_removed(cgrp) && list_empty(&cgrp->release_list)) { @@ -5056,24 +4971,11 @@ EXPORT_SYMBOL_GPL(__css_tryget); /* Caller must verify that the css is not for root cgroup */ void __css_put(struct cgroup_subsys_state *css) { - struct cgroup *cgrp = css->cgroup; int v; - rcu_read_lock(); v = css_unbias_refcnt(atomic_dec_return(&css->refcnt)); - - switch (v) { - case 1: - if (notify_on_release(cgrp)) { - set_bit(CGRP_RELEASABLE, &cgrp->flags); - check_for_release(cgrp); - } - break; - case 0: + if (v == 0) schedule_work(&css->dput_work); - break; - } - rcu_read_unlock(); } EXPORT_SYMBOL_GPL(__css_put); @@ -5274,7 +5176,7 @@ EXPORT_SYMBOL_GPL(free_css_id); static struct css_id *get_new_cssid(struct cgroup_subsys *ss, int depth) { struct css_id *newid; - int myid, error, size; + int ret, size; BUG_ON(!ss->use_id); @@ -5282,35 +5184,24 @@ static struct css_id *get_new_cssid(struct cgroup_subsys *ss, int depth) newid = kzalloc(size, GFP_KERNEL); if (!newid) return ERR_PTR(-ENOMEM); - /* get id */ - if (unlikely(!idr_pre_get(&ss->idr, GFP_KERNEL))) { - error = -ENOMEM; - goto err_out; - } + + idr_preload(GFP_KERNEL); spin_lock(&ss->id_lock); /* Don't use 0. allocates an ID of 1-65535 */ - error = idr_get_new_above(&ss->idr, newid, 1, &myid); + ret = idr_alloc(&ss->idr, newid, 1, CSS_ID_MAX + 1, GFP_NOWAIT); spin_unlock(&ss->id_lock); + idr_preload_end(); /* Returns error when there are no free spaces for new ID.*/ - if (error) { - error = -ENOSPC; + if (ret < 0) goto err_out; - } - if (myid > CSS_ID_MAX) - goto remove_idr; - newid->id = myid; + newid->id = ret; newid->depth = depth; return newid; -remove_idr: - error = -ENOSPC; - spin_lock(&ss->id_lock); - idr_remove(&ss->idr, myid); - spin_unlock(&ss->id_lock); err_out: kfree(newid); - return ERR_PTR(error); + return ERR_PTR(ret); } @@ -5383,55 +5274,6 @@ struct cgroup_subsys_state *css_lookup(struct cgroup_subsys *ss, int id) } EXPORT_SYMBOL_GPL(css_lookup); -/** - * css_get_next - lookup next cgroup under specified hierarchy. - * @ss: pointer to subsystem - * @id: current position of iteration. - * @root: pointer to css. search tree under this. - * @foundid: position of found object. - * - * Search next css under the specified hierarchy of rootid. Calling under - * rcu_read_lock() is necessary. Returns NULL if it reaches the end. - */ -struct cgroup_subsys_state * -css_get_next(struct cgroup_subsys *ss, int id, - struct cgroup_subsys_state *root, int *foundid) -{ - struct cgroup_subsys_state *ret = NULL; - struct css_id *tmp; - int tmpid; - int rootid = css_id(root); - int depth = css_depth(root); - - if (!rootid) - return NULL; - - BUG_ON(!ss->use_id); - WARN_ON_ONCE(!rcu_read_lock_held()); - - /* fill start point for scan */ - tmpid = id; - while (1) { - /* - * scan next entry from bitmap(tree), tmpid is updated after - * idr_get_next(). - */ - tmp = idr_get_next(&ss->idr, &tmpid); - if (!tmp) - break; - if (tmp->depth >= depth && tmp->stack[depth] == rootid) { - ret = rcu_dereference(tmp->css); - if (ret) { - *foundid = tmpid; - break; - } - } - /* continue to scan from next id */ - tmpid = tmpid + 1; - } - return ret; -} - /* * get corresponding css from file open on cgroupfs directory */ @@ -5441,7 +5283,7 @@ struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id) struct inode *inode; struct cgroup_subsys_state *css; - inode = f->f_dentry->d_inode; + inode = file_inode(f); /* check in cgroup filesystem dir */ if (inode->i_op != &cgroup_dir_inode_operations) return ERR_PTR(-EBADF); diff --git a/kernel/compat.c b/kernel/compat.c index 36700e9e2be9..0a09e481b70b 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -290,8 +290,8 @@ static inline long put_compat_itimerval(struct compat_itimerval __user *o, __put_user(i->it_value.tv_usec, &o->it_value.tv_usec))); } -asmlinkage long compat_sys_getitimer(int which, - struct compat_itimerval __user *it) +COMPAT_SYSCALL_DEFINE2(getitimer, int, which, + struct compat_itimerval __user *, it) { struct itimerval kit; int error; @@ -302,9 +302,9 @@ asmlinkage long compat_sys_getitimer(int which, return error; } -asmlinkage long compat_sys_setitimer(int which, - struct compat_itimerval __user *in, - struct compat_itimerval __user *out) +COMPAT_SYSCALL_DEFINE3(setitimer, int, which, + struct compat_itimerval __user *, in, + struct compat_itimerval __user *, out) { struct itimerval kin, kout; int error; @@ -381,9 +381,9 @@ static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set) memcpy(blocked->sig, &set, sizeof(set)); } -asmlinkage long compat_sys_sigprocmask(int how, - compat_old_sigset_t __user *nset, - compat_old_sigset_t __user *oset) +COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how, + compat_old_sigset_t __user *, nset, + compat_old_sigset_t __user *, oset) { old_sigset_t old_set, new_set; sigset_t new_blocked; @@ -516,25 +516,6 @@ int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru) return 0; } -asmlinkage long compat_sys_getrusage(int who, struct compat_rusage __user *ru) -{ - struct rusage r; - int ret; - mm_segment_t old_fs = get_fs(); - - set_fs(KERNEL_DS); - ret = sys_getrusage(who, (struct rusage __user *) &r); - set_fs(old_fs); - - if (ret) - return ret; - - if (put_compat_rusage(&r, ru)) - return -EFAULT; - - return 0; -} - COMPAT_SYSCALL_DEFINE4(wait4, compat_pid_t, pid, compat_uint_t __user *, stat_addr, @@ -593,7 +574,7 @@ COMPAT_SYSCALL_DEFINE5(waitid, else ret = put_compat_rusage(&ru, uru); if (ret) - return ret; + return -EFAULT; } BUG_ON(info.si_code & __SI_MASK); @@ -971,7 +952,7 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, } void -sigset_from_compat (sigset_t *set, compat_sigset_t *compat) +sigset_from_compat(sigset_t *set, const compat_sigset_t *compat) { switch (_NSIG_WORDS) { case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 ); @@ -982,10 +963,20 @@ sigset_from_compat (sigset_t *set, compat_sigset_t *compat) } EXPORT_SYMBOL_GPL(sigset_from_compat); -asmlinkage long -compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese, - struct compat_siginfo __user *uinfo, - struct compat_timespec __user *uts, compat_size_t sigsetsize) +void +sigset_to_compat(compat_sigset_t *compat, const sigset_t *set) +{ + switch (_NSIG_WORDS) { + case 4: compat->sig[7] = (set->sig[3] >> 32); compat->sig[6] = set->sig[3]; + case 3: compat->sig[5] = (set->sig[2] >> 32); compat->sig[4] = set->sig[2]; + case 2: compat->sig[3] = (set->sig[1] >> 32); compat->sig[2] = set->sig[1]; + case 1: compat->sig[1] = (set->sig[0] >> 32); compat->sig[0] = set->sig[0]; + } +} + +COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese, + struct compat_siginfo __user *, uinfo, + struct compat_timespec __user *, uts, compat_size_t, sigsetsize) { compat_sigset_t s32; sigset_t s; @@ -1013,18 +1004,6 @@ compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese, } return ret; - -} - -asmlinkage long -compat_sys_rt_tgsigqueueinfo(compat_pid_t tgid, compat_pid_t pid, int sig, - struct compat_siginfo __user *uinfo) -{ - siginfo_t info; - - if (copy_siginfo_from_user32(&info, uinfo)) - return -EFAULT; - return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); } #ifdef __ARCH_WANT_COMPAT_SYS_TIME @@ -1067,23 +1046,6 @@ asmlinkage long compat_sys_stime(compat_time_t __user *tptr) #endif /* __ARCH_WANT_COMPAT_SYS_TIME */ -#ifdef __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND -asmlinkage long compat_sys_rt_sigsuspend(compat_sigset_t __user *unewset, compat_size_t sigsetsize) -{ - sigset_t newset; - compat_sigset_t newset32; - - /* XXX: Don't preclude handling different sized sigset_t's. */ - if (sigsetsize != sizeof(sigset_t)) - return -EINVAL; - - if (copy_from_user(&newset32, unewset, sizeof(compat_sigset_t))) - return -EFAULT; - sigset_from_compat(&newset, &newset32); - return sigsuspend(&newset); -} -#endif /* __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND */ - asmlinkage long compat_sys_adjtimex(struct compat_timex __user *utp) { struct timex txc; @@ -1157,74 +1119,9 @@ asmlinkage long compat_sys_migrate_pages(compat_pid_t pid, } #endif -struct compat_sysinfo { - s32 uptime; - u32 loads[3]; - u32 totalram; - u32 freeram; - u32 sharedram; - u32 bufferram; - u32 totalswap; - u32 freeswap; - u16 procs; - u16 pad; - u32 totalhigh; - u32 freehigh; - u32 mem_unit; - char _f[20-2*sizeof(u32)-sizeof(int)]; -}; - -asmlinkage long -compat_sys_sysinfo(struct compat_sysinfo __user *info) -{ - struct sysinfo s; - - do_sysinfo(&s); - - /* Check to see if any memory value is too large for 32-bit and scale - * down if needed - */ - if ((s.totalram >> 32) || (s.totalswap >> 32)) { - int bitcount = 0; - - while (s.mem_unit < PAGE_SIZE) { - s.mem_unit <<= 1; - bitcount++; - } - - s.totalram >>= bitcount; - s.freeram >>= bitcount; - s.sharedram >>= bitcount; - s.bufferram >>= bitcount; - s.totalswap >>= bitcount; - s.freeswap >>= bitcount; - s.totalhigh >>= bitcount; - s.freehigh >>= bitcount; - } - - if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) || - __put_user (s.uptime, &info->uptime) || - __put_user (s.loads[0], &info->loads[0]) || - __put_user (s.loads[1], &info->loads[1]) || - __put_user (s.loads[2], &info->loads[2]) || - __put_user (s.totalram, &info->totalram) || - __put_user (s.freeram, &info->freeram) || - __put_user (s.sharedram, &info->sharedram) || - __put_user (s.bufferram, &info->bufferram) || - __put_user (s.totalswap, &info->totalswap) || - __put_user (s.freeswap, &info->freeswap) || - __put_user (s.procs, &info->procs) || - __put_user (s.totalhigh, &info->totalhigh) || - __put_user (s.freehigh, &info->freehigh) || - __put_user (s.mem_unit, &info->mem_unit)) - return -EFAULT; - - return 0; -} - -#ifdef __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL -asmlinkage long compat_sys_sched_rr_get_interval(compat_pid_t pid, - struct compat_timespec __user *interval) +COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval, + compat_pid_t, pid, + struct compat_timespec __user *, interval) { struct timespec t; int ret; @@ -1237,7 +1134,6 @@ asmlinkage long compat_sys_sched_rr_get_interval(compat_pid_t pid, return -EFAULT; return ret; } -#endif /* __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL */ /* * Allocate user-space memory for the duration of a single system call, diff --git a/kernel/configs.c b/kernel/configs.c index 42e8fa075eed..c18b1f1ae515 100644 --- a/kernel/configs.c +++ b/kernel/configs.c @@ -79,7 +79,7 @@ static int __init ikconfig_init(void) if (!entry) return -ENOMEM; - entry->size = kernel_config_data_size; + proc_set_size(entry, kernel_config_data_size); return 0; } diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index e0e07fd55508..65349f07b878 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -1,29 +1,41 @@ +/* + * Context tracking: Probe on high level context boundaries such as kernel + * and userspace. This includes syscalls and exceptions entry/exit. + * + * This is used by RCU to remove its dependency on the timer tick while a CPU + * runs in userspace. + * + * Started by Frederic Weisbecker: + * + * Copyright (C) 2012 Red Hat, Inc., Frederic Weisbecker <fweisbec@redhat.com> + * + * Many thanks to Gilad Ben-Yossef, Paul McKenney, Ingo Molnar, Andrew Morton, + * Steven Rostedt, Peter Zijlstra for suggestions and improvements. + * + */ + #include <linux/context_tracking.h> +#include <linux/kvm_host.h> #include <linux/rcupdate.h> #include <linux/sched.h> -#include <linux/percpu.h> #include <linux/hardirq.h> +#include <linux/export.h> -struct context_tracking { - /* - * When active is false, hooks are not set to - * minimize overhead: TIF flags are cleared - * and calls to user_enter/exit are ignored. This - * may be further optimized using static keys. - */ - bool active; - enum { - IN_KERNEL = 0, - IN_USER, - } state; -}; - -static DEFINE_PER_CPU(struct context_tracking, context_tracking) = { +DEFINE_PER_CPU(struct context_tracking, context_tracking) = { #ifdef CONFIG_CONTEXT_TRACKING_FORCE .active = true, #endif }; +/** + * user_enter - Inform the context tracking that the CPU is going to + * enter userspace mode. + * + * This function must be called right before we switch from the kernel + * to userspace, when it's guaranteed the remaining kernel instructions + * to execute won't use any RCU read side critical section because this + * function sets RCU in extended quiescent state. + */ void user_enter(void) { unsigned long flags; @@ -39,40 +51,90 @@ void user_enter(void) if (in_interrupt()) return; + /* Kernel threads aren't supposed to go to userspace */ WARN_ON_ONCE(!current->mm); local_irq_save(flags); if (__this_cpu_read(context_tracking.active) && __this_cpu_read(context_tracking.state) != IN_USER) { - __this_cpu_write(context_tracking.state, IN_USER); + /* + * At this stage, only low level arch entry code remains and + * then we'll run in userspace. We can assume there won't be + * any RCU read-side critical section until the next call to + * user_exit() or rcu_irq_enter(). Let's remove RCU's dependency + * on the tick. + */ + vtime_user_enter(current); rcu_user_enter(); + __this_cpu_write(context_tracking.state, IN_USER); } local_irq_restore(flags); } + +/** + * user_exit - Inform the context tracking that the CPU is + * exiting userspace mode and entering the kernel. + * + * This function must be called after we entered the kernel from userspace + * before any use of RCU read side critical section. This potentially include + * any high level kernel code like syscalls, exceptions, signal handling, etc... + * + * This call supports re-entrancy. This way it can be called from any exception + * handler without needing to know if we came from userspace or not. + */ void user_exit(void) { unsigned long flags; - /* - * Some contexts may involve an exception occuring in an irq, - * leading to that nesting: - * rcu_irq_enter() rcu_user_exit() rcu_user_exit() rcu_irq_exit() - * This would mess up the dyntick_nesting count though. And rcu_irq_*() - * helpers are enough to protect RCU uses inside the exception. So - * just return immediately if we detect we are in an IRQ. - */ if (in_interrupt()) return; local_irq_save(flags); if (__this_cpu_read(context_tracking.state) == IN_USER) { - __this_cpu_write(context_tracking.state, IN_KERNEL); + /* + * We are going to run code that may use RCU. Inform + * RCU core about that (ie: we may need the tick again). + */ rcu_user_exit(); + vtime_user_exit(current); + __this_cpu_write(context_tracking.state, IN_KERNEL); } local_irq_restore(flags); } +void guest_enter(void) +{ + if (vtime_accounting_enabled()) + vtime_guest_enter(current); + else + __guest_enter(); +} +EXPORT_SYMBOL_GPL(guest_enter); + +void guest_exit(void) +{ + if (vtime_accounting_enabled()) + vtime_guest_exit(current); + else + __guest_exit(); +} +EXPORT_SYMBOL_GPL(guest_exit); + + +/** + * context_tracking_task_switch - context switch the syscall callbacks + * @prev: the task that is being switched out + * @next: the task that is being switched in + * + * The context tracking uses the syscall slow path to implement its user-kernel + * boundaries probes on syscalls. This way it doesn't impact the syscall fast + * path on CPUs that don't do context tracking. + * + * But we need to clear the flag on the previous task because it may later + * migrate to some CPU that doesn't do the context tracking. As such the TIF + * flag may not be desired there. + */ void context_tracking_task_switch(struct task_struct *prev, struct task_struct *next) { diff --git a/kernel/cpu.c b/kernel/cpu.c index 3046a503242c..b5e4ab2d427e 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -224,11 +224,13 @@ void clear_tasks_mm_cpumask(int cpu) static inline void check_for_tasks(int cpu) { struct task_struct *p; + cputime_t utime, stime; write_lock_irq(&tasklist_lock); for_each_process(p) { + task_cputime(p, &utime, &stime); if (task_cpu(p) == cpu && p->state == TASK_RUNNING && - (p->utime || p->stime)) + (utime || stime)) printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d " "(state = %ld, flags = %x)\n", p->comm, task_pid_nr(p), cpu, @@ -254,6 +256,8 @@ static int __ref take_cpu_down(void *_param) return err; cpu_notify(CPU_DYING | param->mod, param->hcpu); + /* Park the stopper thread */ + kthread_park(current); return 0; } diff --git a/kernel/cpu/Makefile b/kernel/cpu/Makefile new file mode 100644 index 000000000000..59ab052ef7a0 --- /dev/null +++ b/kernel/cpu/Makefile @@ -0,0 +1 @@ +obj-y = idle.o diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c new file mode 100644 index 000000000000..8b86c0c68edf --- /dev/null +++ b/kernel/cpu/idle.c @@ -0,0 +1,116 @@ +/* + * Generic entry point for the idle threads + */ +#include <linux/sched.h> +#include <linux/cpu.h> +#include <linux/tick.h> +#include <linux/mm.h> + +#include <asm/tlb.h> + +#include <trace/events/power.h> + +static int __read_mostly cpu_idle_force_poll; + +void cpu_idle_poll_ctrl(bool enable) +{ + if (enable) { + cpu_idle_force_poll++; + } else { + cpu_idle_force_poll--; + WARN_ON_ONCE(cpu_idle_force_poll < 0); + } +} + +#ifdef CONFIG_GENERIC_IDLE_POLL_SETUP +static int __init cpu_idle_poll_setup(char *__unused) +{ + cpu_idle_force_poll = 1; + return 1; +} +__setup("nohlt", cpu_idle_poll_setup); + +static int __init cpu_idle_nopoll_setup(char *__unused) +{ + cpu_idle_force_poll = 0; + return 1; +} +__setup("hlt", cpu_idle_nopoll_setup); +#endif + +static inline int cpu_idle_poll(void) +{ + trace_cpu_idle_rcuidle(0, smp_processor_id()); + local_irq_enable(); + while (!need_resched()) + cpu_relax(); + trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); + return 1; +} + +/* Weak implementations for optional arch specific functions */ +void __weak arch_cpu_idle_prepare(void) { } +void __weak arch_cpu_idle_enter(void) { } +void __weak arch_cpu_idle_exit(void) { } +void __weak arch_cpu_idle_dead(void) { } +void __weak arch_cpu_idle(void) +{ + cpu_idle_force_poll = 1; +} + +/* + * Generic idle loop implementation + */ +static void cpu_idle_loop(void) +{ + while (1) { + tick_nohz_idle_enter(); + + while (!need_resched()) { + check_pgt_cache(); + rmb(); + + if (cpu_is_offline(smp_processor_id())) + arch_cpu_idle_dead(); + + local_irq_disable(); + arch_cpu_idle_enter(); + + /* + * In poll mode we reenable interrupts and spin. + * + * Also if we detected in the wakeup from idle + * path that the tick broadcast device expired + * for us, we don't want to go deep idle as we + * know that the IPI is going to arrive right + * away + */ + if (cpu_idle_force_poll || tick_check_broadcast_expired()) { + cpu_idle_poll(); + } else { + current_clr_polling(); + if (!need_resched()) { + stop_critical_timings(); + rcu_idle_enter(); + arch_cpu_idle(); + WARN_ON_ONCE(irqs_disabled()); + rcu_idle_exit(); + start_critical_timings(); + } else { + local_irq_enable(); + } + current_set_polling(); + } + arch_cpu_idle_exit(); + } + tick_nohz_idle_exit(); + schedule_preempt_disabled(); + } +} + +void cpu_startup_entry(enum cpuhp_state state) +{ + current_set_polling(); + arch_cpu_idle_prepare(); + cpu_idle_loop(); +} diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 7bb63eea6eb8..64b3f791bbe5 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -61,14 +61,6 @@ #include <linux/cgroup.h> /* - * Workqueue for cpuset related tasks. - * - * Using kevent workqueue may cause deadlock when memory_migrate - * is set. So we create a separate workqueue thread for cpuset. - */ -static struct workqueue_struct *cpuset_wq; - -/* * Tracks how many cpusets are currently defined in system. * When there is only one cpuset (the root cpuset) we can * short circuit some hooks. @@ -95,18 +87,21 @@ struct cpuset { cpumask_var_t cpus_allowed; /* CPUs allowed to tasks in cpuset */ nodemask_t mems_allowed; /* Memory Nodes allowed to tasks */ - struct cpuset *parent; /* my parent */ - struct fmeter fmeter; /* memory_pressure filter */ + /* + * Tasks are being attached to this cpuset. Used to prevent + * zeroing cpus/mems_allowed between ->can_attach() and ->attach(). + */ + int attach_in_progress; + /* partition number for rebuild_sched_domains() */ int pn; /* for custom sched domain */ int relax_domain_level; - /* used for walking a cpuset hierarchy */ - struct list_head stack_list; + struct work_struct hotplug_work; }; /* Retrieve the cpuset for a cgroup */ @@ -123,6 +118,15 @@ static inline struct cpuset *task_cs(struct task_struct *task) struct cpuset, css); } +static inline struct cpuset *parent_cs(const struct cpuset *cs) +{ + struct cgroup *pcgrp = cs->css.cgroup->parent; + + if (pcgrp) + return cgroup_cs(pcgrp); + return NULL; +} + #ifdef CONFIG_NUMA static inline bool task_has_mempolicy(struct task_struct *task) { @@ -138,6 +142,7 @@ static inline bool task_has_mempolicy(struct task_struct *task) /* bits in struct cpuset flags field */ typedef enum { + CS_ONLINE, CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE, CS_MEM_HARDWALL, @@ -147,13 +152,12 @@ typedef enum { CS_SPREAD_SLAB, } cpuset_flagbits_t; -/* the type of hotplug event */ -enum hotplug_event { - CPUSET_CPU_OFFLINE, - CPUSET_MEM_OFFLINE, -}; - /* convenient tests for these bits */ +static inline bool is_cpuset_online(const struct cpuset *cs) +{ + return test_bit(CS_ONLINE, &cs->flags); +} + static inline int is_cpu_exclusive(const struct cpuset *cs) { return test_bit(CS_CPU_EXCLUSIVE, &cs->flags); @@ -190,27 +194,52 @@ static inline int is_spread_slab(const struct cpuset *cs) } static struct cpuset top_cpuset = { - .flags = ((1 << CS_CPU_EXCLUSIVE) | (1 << CS_MEM_EXCLUSIVE)), + .flags = ((1 << CS_ONLINE) | (1 << CS_CPU_EXCLUSIVE) | + (1 << CS_MEM_EXCLUSIVE)), }; +/** + * cpuset_for_each_child - traverse online children of a cpuset + * @child_cs: loop cursor pointing to the current child + * @pos_cgrp: used for iteration + * @parent_cs: target cpuset to walk children of + * + * Walk @child_cs through the online children of @parent_cs. Must be used + * with RCU read locked. + */ +#define cpuset_for_each_child(child_cs, pos_cgrp, parent_cs) \ + cgroup_for_each_child((pos_cgrp), (parent_cs)->css.cgroup) \ + if (is_cpuset_online(((child_cs) = cgroup_cs((pos_cgrp))))) + +/** + * cpuset_for_each_descendant_pre - pre-order walk of a cpuset's descendants + * @des_cs: loop cursor pointing to the current descendant + * @pos_cgrp: used for iteration + * @root_cs: target cpuset to walk ancestor of + * + * Walk @des_cs through the online descendants of @root_cs. Must be used + * with RCU read locked. The caller may modify @pos_cgrp by calling + * cgroup_rightmost_descendant() to skip subtree. + */ +#define cpuset_for_each_descendant_pre(des_cs, pos_cgrp, root_cs) \ + cgroup_for_each_descendant_pre((pos_cgrp), (root_cs)->css.cgroup) \ + if (is_cpuset_online(((des_cs) = cgroup_cs((pos_cgrp))))) + /* - * There are two global mutexes guarding cpuset structures. The first - * is the main control groups cgroup_mutex, accessed via - * cgroup_lock()/cgroup_unlock(). The second is the cpuset-specific - * callback_mutex, below. They can nest. It is ok to first take - * cgroup_mutex, then nest callback_mutex. We also require taking - * task_lock() when dereferencing a task's cpuset pointer. See "The - * task_lock() exception", at the end of this comment. - * - * A task must hold both mutexes to modify cpusets. If a task - * holds cgroup_mutex, then it blocks others wanting that mutex, - * ensuring that it is the only task able to also acquire callback_mutex - * and be able to modify cpusets. It can perform various checks on - * the cpuset structure first, knowing nothing will change. It can - * also allocate memory while just holding cgroup_mutex. While it is - * performing these checks, various callback routines can briefly - * acquire callback_mutex to query cpusets. Once it is ready to make - * the changes, it takes callback_mutex, blocking everyone else. + * There are two global mutexes guarding cpuset structures - cpuset_mutex + * and callback_mutex. The latter may nest inside the former. We also + * require taking task_lock() when dereferencing a task's cpuset pointer. + * See "The task_lock() exception", at the end of this comment. + * + * A task must hold both mutexes to modify cpusets. If a task holds + * cpuset_mutex, then it blocks others wanting that mutex, ensuring that it + * is the only task able to also acquire callback_mutex and be able to + * modify cpusets. It can perform various checks on the cpuset structure + * first, knowing nothing will change. It can also allocate memory while + * just holding cpuset_mutex. While it is performing these checks, various + * callback routines can briefly acquire callback_mutex to query cpusets. + * Once it is ready to make the changes, it takes callback_mutex, blocking + * everyone else. * * Calls to the kernel memory allocator can not be made while holding * callback_mutex, as that would risk double tripping on callback_mutex @@ -232,18 +261,19 @@ static struct cpuset top_cpuset = { * guidelines for accessing subsystem state in kernel/cgroup.c */ +static DEFINE_MUTEX(cpuset_mutex); static DEFINE_MUTEX(callback_mutex); /* - * cpuset_buffer_lock protects both the cpuset_name and cpuset_nodelist - * buffers. They are statically allocated to prevent using excess stack - * when calling cpuset_print_task_mems_allowed(). + * CPU / memory hotplug is handled asynchronously. */ -#define CPUSET_NAME_LEN (128) -#define CPUSET_NODELIST_LEN (256) -static char cpuset_name[CPUSET_NAME_LEN]; -static char cpuset_nodelist[CPUSET_NODELIST_LEN]; -static DEFINE_SPINLOCK(cpuset_buffer_lock); +static struct workqueue_struct *cpuset_propagate_hotplug_wq; + +static void cpuset_hotplug_workfn(struct work_struct *work); +static void cpuset_propagate_hotplug_workfn(struct work_struct *work); +static void schedule_cpuset_propagate_hotplug(struct cpuset *cs); + +static DECLARE_WORK(cpuset_hotplug_work, cpuset_hotplug_workfn); /* * This is ugly, but preserves the userspace API for existing cpuset @@ -289,7 +319,7 @@ static void guarantee_online_cpus(const struct cpuset *cs, struct cpumask *pmask) { while (cs && !cpumask_intersects(cs->cpus_allowed, cpu_online_mask)) - cs = cs->parent; + cs = parent_cs(cs); if (cs) cpumask_and(pmask, cs->cpus_allowed, cpu_online_mask); else @@ -314,7 +344,7 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask) { while (cs && !nodes_intersects(cs->mems_allowed, node_states[N_MEMORY])) - cs = cs->parent; + cs = parent_cs(cs); if (cs) nodes_and(*pmask, cs->mems_allowed, node_states[N_MEMORY]); @@ -326,7 +356,7 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask) /* * update task's spread flag if cpuset's page/slab spread flag is set * - * Called with callback_mutex/cgroup_mutex held + * Called with callback_mutex/cpuset_mutex held */ static void cpuset_update_task_spread_flag(struct cpuset *cs, struct task_struct *tsk) @@ -346,7 +376,7 @@ static void cpuset_update_task_spread_flag(struct cpuset *cs, * * One cpuset is a subset of another if all its allowed CPUs and * Memory Nodes are a subset of the other, and its exclusive flags - * are only set if the other's are set. Call holding cgroup_mutex. + * are only set if the other's are set. Call holding cpuset_mutex. */ static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q) @@ -395,7 +425,7 @@ static void free_trial_cpuset(struct cpuset *trial) * If we replaced the flag and mask values of the current cpuset * (cur) with those values in the trial cpuset (trial), would * our various subset and exclusive rules still be valid? Presumes - * cgroup_mutex held. + * cpuset_mutex held. * * 'cur' is the address of an actual, in-use cpuset. Operations * such as list traversal that depend on the actual address of the @@ -412,48 +442,58 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial) { struct cgroup *cont; struct cpuset *c, *par; + int ret; + + rcu_read_lock(); /* Each of our child cpusets must be a subset of us */ - list_for_each_entry(cont, &cur->css.cgroup->children, sibling) { - if (!is_cpuset_subset(cgroup_cs(cont), trial)) - return -EBUSY; - } + ret = -EBUSY; + cpuset_for_each_child(c, cont, cur) + if (!is_cpuset_subset(c, trial)) + goto out; /* Remaining checks don't apply to root cpuset */ + ret = 0; if (cur == &top_cpuset) - return 0; + goto out; - par = cur->parent; + par = parent_cs(cur); /* We must be a subset of our parent cpuset */ + ret = -EACCES; if (!is_cpuset_subset(trial, par)) - return -EACCES; + goto out; /* * If either I or some sibling (!= me) is exclusive, we can't * overlap */ - list_for_each_entry(cont, &par->css.cgroup->children, sibling) { - c = cgroup_cs(cont); + ret = -EINVAL; + cpuset_for_each_child(c, cont, par) { if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) && c != cur && cpumask_intersects(trial->cpus_allowed, c->cpus_allowed)) - return -EINVAL; + goto out; if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) && c != cur && nodes_intersects(trial->mems_allowed, c->mems_allowed)) - return -EINVAL; + goto out; } - /* Cpusets with tasks can't have empty cpus_allowed or mems_allowed */ - if (cgroup_task_count(cur->css.cgroup)) { - if (cpumask_empty(trial->cpus_allowed) || - nodes_empty(trial->mems_allowed)) { - return -ENOSPC; - } - } + /* + * Cpusets with tasks - existing or newly being attached - can't + * have empty cpus_allowed or mems_allowed. + */ + ret = -ENOSPC; + if ((cgroup_task_count(cur->css.cgroup) || cur->attach_in_progress) && + (cpumask_empty(trial->cpus_allowed) || + nodes_empty(trial->mems_allowed))) + goto out; - return 0; + ret = 0; +out: + rcu_read_unlock(); + return ret; } #ifdef CONFIG_SMP @@ -474,31 +514,24 @@ update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c) return; } -static void -update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c) +static void update_domain_attr_tree(struct sched_domain_attr *dattr, + struct cpuset *root_cs) { - LIST_HEAD(q); - - list_add(&c->stack_list, &q); - while (!list_empty(&q)) { - struct cpuset *cp; - struct cgroup *cont; - struct cpuset *child; - - cp = list_first_entry(&q, struct cpuset, stack_list); - list_del(q.next); + struct cpuset *cp; + struct cgroup *pos_cgrp; - if (cpumask_empty(cp->cpus_allowed)) + rcu_read_lock(); + cpuset_for_each_descendant_pre(cp, pos_cgrp, root_cs) { + /* skip the whole subtree if @cp doesn't have any CPU */ + if (cpumask_empty(cp->cpus_allowed)) { + pos_cgrp = cgroup_rightmost_descendant(pos_cgrp); continue; + } if (is_sched_load_balance(cp)) update_domain_attr(dattr, cp); - - list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { - child = cgroup_cs(cont); - list_add_tail(&child->stack_list, &q); - } } + rcu_read_unlock(); } /* @@ -520,7 +553,7 @@ update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c) * domains when operating in the severe memory shortage situations * that could cause allocation failures below. * - * Must be called with cgroup_lock held. + * Must be called with cpuset_mutex held. * * The three key local variables below are: * q - a linked-list queue of cpuset pointers, used to implement a @@ -558,7 +591,6 @@ update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c) static int generate_sched_domains(cpumask_var_t **domains, struct sched_domain_attr **attributes) { - LIST_HEAD(q); /* queue of cpusets to be scanned */ struct cpuset *cp; /* scans q */ struct cpuset **csa; /* array of all cpuset ptrs */ int csn; /* how many cpuset ptrs in csa so far */ @@ -567,6 +599,7 @@ static int generate_sched_domains(cpumask_var_t **domains, struct sched_domain_attr *dattr; /* attributes for custom domains */ int ndoms = 0; /* number of sched domains in result */ int nslot; /* next empty doms[] struct cpumask slot */ + struct cgroup *pos_cgrp; doms = NULL; dattr = NULL; @@ -594,33 +627,27 @@ static int generate_sched_domains(cpumask_var_t **domains, goto done; csn = 0; - list_add(&top_cpuset.stack_list, &q); - while (!list_empty(&q)) { - struct cgroup *cont; - struct cpuset *child; /* scans child cpusets of cp */ - - cp = list_first_entry(&q, struct cpuset, stack_list); - list_del(q.next); - - if (cpumask_empty(cp->cpus_allowed)) - continue; - + rcu_read_lock(); + cpuset_for_each_descendant_pre(cp, pos_cgrp, &top_cpuset) { /* - * All child cpusets contain a subset of the parent's cpus, so - * just skip them, and then we call update_domain_attr_tree() - * to calc relax_domain_level of the corresponding sched - * domain. + * Continue traversing beyond @cp iff @cp has some CPUs and + * isn't load balancing. The former is obvious. The + * latter: All child cpusets contain a subset of the + * parent's cpus, so just skip them, and then we call + * update_domain_attr_tree() to calc relax_domain_level of + * the corresponding sched domain. */ - if (is_sched_load_balance(cp)) { - csa[csn++] = cp; + if (!cpumask_empty(cp->cpus_allowed) && + !is_sched_load_balance(cp)) continue; - } - list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { - child = cgroup_cs(cont); - list_add_tail(&child->stack_list, &q); - } - } + if (is_sched_load_balance(cp)) + csa[csn++] = cp; + + /* skip @cp's subtree */ + pos_cgrp = cgroup_rightmost_descendant(pos_cgrp); + } + rcu_read_unlock(); for (i = 0; i < csn; i++) csa[i]->pn = i; @@ -725,82 +752,50 @@ done: /* * Rebuild scheduler domains. * - * Call with neither cgroup_mutex held nor within get_online_cpus(). - * Takes both cgroup_mutex and get_online_cpus(). + * If the flag 'sched_load_balance' of any cpuset with non-empty + * 'cpus' changes, or if the 'cpus' allowed changes in any cpuset + * which has that flag enabled, or if any cpuset with a non-empty + * 'cpus' is removed, then call this routine to rebuild the + * scheduler's dynamic sched domains. * - * Cannot be directly called from cpuset code handling changes - * to the cpuset pseudo-filesystem, because it cannot be called - * from code that already holds cgroup_mutex. + * Call with cpuset_mutex held. Takes get_online_cpus(). */ -static void do_rebuild_sched_domains(struct work_struct *unused) +static void rebuild_sched_domains_locked(void) { struct sched_domain_attr *attr; cpumask_var_t *doms; int ndoms; + lockdep_assert_held(&cpuset_mutex); get_online_cpus(); + /* + * We have raced with CPU hotplug. Don't do anything to avoid + * passing doms with offlined cpu to partition_sched_domains(). + * Anyways, hotplug work item will rebuild sched domains. + */ + if (!cpumask_equal(top_cpuset.cpus_allowed, cpu_active_mask)) + goto out; + /* Generate domain masks and attrs */ - cgroup_lock(); ndoms = generate_sched_domains(&doms, &attr); - cgroup_unlock(); /* Have scheduler rebuild the domains */ partition_sched_domains(ndoms, doms, attr); - +out: put_online_cpus(); } #else /* !CONFIG_SMP */ -static void do_rebuild_sched_domains(struct work_struct *unused) -{ -} - -static int generate_sched_domains(cpumask_var_t **domains, - struct sched_domain_attr **attributes) +static void rebuild_sched_domains_locked(void) { - *domains = NULL; - return 1; } #endif /* CONFIG_SMP */ -static DECLARE_WORK(rebuild_sched_domains_work, do_rebuild_sched_domains); - -/* - * Rebuild scheduler domains, asynchronously via workqueue. - * - * If the flag 'sched_load_balance' of any cpuset with non-empty - * 'cpus' changes, or if the 'cpus' allowed changes in any cpuset - * which has that flag enabled, or if any cpuset with a non-empty - * 'cpus' is removed, then call this routine to rebuild the - * scheduler's dynamic sched domains. - * - * The rebuild_sched_domains() and partition_sched_domains() - * routines must nest cgroup_lock() inside get_online_cpus(), - * but such cpuset changes as these must nest that locking the - * other way, holding cgroup_lock() for much of the code. - * - * So in order to avoid an ABBA deadlock, the cpuset code handling - * these user changes delegates the actual sched domain rebuilding - * to a separate workqueue thread, which ends up processing the - * above do_rebuild_sched_domains() function. - */ -static void async_rebuild_sched_domains(void) -{ - queue_work(cpuset_wq, &rebuild_sched_domains_work); -} - -/* - * Accomplishes the same scheduler domain rebuild as the above - * async_rebuild_sched_domains(), however it directly calls the - * rebuild routine synchronously rather than calling it via an - * asynchronous work thread. - * - * This can only be called from code that is not holding - * cgroup_mutex (not nested in a cgroup_lock() call.) - */ void rebuild_sched_domains(void) { - do_rebuild_sched_domains(NULL); + mutex_lock(&cpuset_mutex); + rebuild_sched_domains_locked(); + mutex_unlock(&cpuset_mutex); } /** @@ -808,7 +803,7 @@ void rebuild_sched_domains(void) * @tsk: task to test * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner * - * Call with cgroup_mutex held. May take callback_mutex during call. + * Call with cpuset_mutex held. May take callback_mutex during call. * Called for each task in a cgroup by cgroup_scan_tasks(). * Return nonzero if this tasks's cpus_allowed mask should be changed (in other * words, if its mask is not equal to its cpuset's mask). @@ -829,7 +824,7 @@ static int cpuset_test_cpumask(struct task_struct *tsk, * cpus_allowed mask needs to be changed. * * We don't need to re-check for the cgroup/cpuset membership, since we're - * holding cgroup_lock() at this point. + * holding cpuset_mutex at this point. */ static void cpuset_change_cpumask(struct task_struct *tsk, struct cgroup_scanner *scan) @@ -842,7 +837,7 @@ static void cpuset_change_cpumask(struct task_struct *tsk, * @cs: the cpuset in which each task's cpus_allowed mask needs to be changed * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks() * - * Called with cgroup_mutex held + * Called with cpuset_mutex held * * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, * calling callback functions for each. @@ -920,7 +915,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, heap_free(&heap); if (is_load_balanced) - async_rebuild_sched_domains(); + rebuild_sched_domains_locked(); return 0; } @@ -932,7 +927,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, * Temporarilly set tasks mems_allowed to target nodes of migration, * so that the migration code can allocate pages on these nodes. * - * Call holding cgroup_mutex, so current's cpuset won't change + * Call holding cpuset_mutex, so current's cpuset won't change * during this call, as manage_mutex holds off any cpuset_attach() * calls. Therefore we don't need to take task_lock around the * call to guarantee_online_mems(), as we know no one is changing @@ -1007,7 +1002,7 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk, /* * Update task's mems_allowed and rebind its mempolicy and vmas' mempolicy * of it to cpuset's new mems_allowed, and migrate pages to new nodes if - * memory_migrate flag is set. Called with cgroup_mutex held. + * memory_migrate flag is set. Called with cpuset_mutex held. */ static void cpuset_change_nodemask(struct task_struct *p, struct cgroup_scanner *scan) @@ -1016,7 +1011,7 @@ static void cpuset_change_nodemask(struct task_struct *p, struct cpuset *cs; int migrate; const nodemask_t *oldmem = scan->data; - static nodemask_t newmems; /* protected by cgroup_mutex */ + static nodemask_t newmems; /* protected by cpuset_mutex */ cs = cgroup_cs(scan->cg); guarantee_online_mems(cs, &newmems); @@ -1043,7 +1038,7 @@ static void *cpuset_being_rebound; * @oldmem: old mems_allowed of cpuset cs * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks() * - * Called with cgroup_mutex held + * Called with cpuset_mutex held * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0 * if @heap != NULL. */ @@ -1065,7 +1060,7 @@ static void update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem, * take while holding tasklist_lock. Forks can happen - the * mpol_dup() cpuset_being_rebound check will catch such forks, * and rebind their vma mempolicies too. Because we still hold - * the global cgroup_mutex, we know that no other rebind effort + * the global cpuset_mutex, we know that no other rebind effort * will be contending for the global variable cpuset_being_rebound. * It's ok if we rebind the same mm twice; mpol_rebind_mm() * is idempotent. Also migrate pages in each mm to new nodes. @@ -1084,7 +1079,7 @@ static void update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem, * mempolicies and if the cpuset is marked 'memory_migrate', * migrate the tasks pages to the new memory. * - * Call with cgroup_mutex held. May take callback_mutex during call. + * Call with cpuset_mutex held. May take callback_mutex during call. * Will take tasklist_lock, scan tasklist for tasks in cpuset cs, * lock each such tasks mm->mmap_sem, scan its vma's and rebind * their mempolicies to the cpusets new mems_allowed. @@ -1168,7 +1163,7 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val) cs->relax_domain_level = val; if (!cpumask_empty(cs->cpus_allowed) && is_sched_load_balance(cs)) - async_rebuild_sched_domains(); + rebuild_sched_domains_locked(); } return 0; @@ -1182,7 +1177,7 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val) * Called by cgroup_scan_tasks() for each task in a cgroup. * * We don't need to re-check for the cgroup/cpuset membership, since we're - * holding cgroup_lock() at this point. + * holding cpuset_mutex at this point. */ static void cpuset_change_flag(struct task_struct *tsk, struct cgroup_scanner *scan) @@ -1195,7 +1190,7 @@ static void cpuset_change_flag(struct task_struct *tsk, * @cs: the cpuset in which each task's spread flags needs to be changed * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks() * - * Called with cgroup_mutex held + * Called with cpuset_mutex held * * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, * calling callback functions for each. @@ -1220,7 +1215,7 @@ static void update_tasks_flags(struct cpuset *cs, struct ptr_heap *heap) * cs: the cpuset to update * turning_on: whether the flag is being set or cleared * - * Call with cgroup_mutex held. + * Call with cpuset_mutex held. */ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, @@ -1260,7 +1255,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, mutex_unlock(&callback_mutex); if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed) - async_rebuild_sched_domains(); + rebuild_sched_domains_locked(); if (spread_flag_changed) update_tasks_flags(cs, &heap); @@ -1368,54 +1363,68 @@ static int fmeter_getrate(struct fmeter *fmp) return val; } -/* - * Protected by cgroup_lock. The nodemasks must be stored globally because - * dynamically allocating them is not allowed in can_attach, and they must - * persist until attach. - */ -static cpumask_var_t cpus_attach; -static nodemask_t cpuset_attach_nodemask_from; -static nodemask_t cpuset_attach_nodemask_to; - -/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */ +/* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */ static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) { struct cpuset *cs = cgroup_cs(cgrp); struct task_struct *task; int ret; + mutex_lock(&cpuset_mutex); + + ret = -ENOSPC; if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) - return -ENOSPC; + goto out_unlock; cgroup_taskset_for_each(task, cgrp, tset) { /* - * Kthreads bound to specific cpus cannot be moved to a new - * cpuset; we cannot change their cpu affinity and - * isolating such threads by their set of allowed nodes is - * unnecessary. Thus, cpusets are not applicable for such - * threads. This prevents checking for success of - * set_cpus_allowed_ptr() on all attached tasks before - * cpus_allowed may be changed. + * Kthreads which disallow setaffinity shouldn't be moved + * to a new cpuset; we don't want to change their cpu + * affinity and isolating such threads by their set of + * allowed nodes is unnecessary. Thus, cpusets are not + * applicable for such threads. This prevents checking for + * success of set_cpus_allowed_ptr() on all attached tasks + * before cpus_allowed may be changed. */ - if (task->flags & PF_THREAD_BOUND) - return -EINVAL; - if ((ret = security_task_setscheduler(task))) - return ret; + ret = -EINVAL; + if (task->flags & PF_NO_SETAFFINITY) + goto out_unlock; + ret = security_task_setscheduler(task); + if (ret) + goto out_unlock; } - /* prepare for attach */ - if (cs == &top_cpuset) - cpumask_copy(cpus_attach, cpu_possible_mask); - else - guarantee_online_cpus(cs, cpus_attach); - - guarantee_online_mems(cs, &cpuset_attach_nodemask_to); + /* + * Mark attach is in progress. This makes validate_change() fail + * changes which zero cpus/mems_allowed. + */ + cs->attach_in_progress++; + ret = 0; +out_unlock: + mutex_unlock(&cpuset_mutex); + return ret; +} - return 0; +static void cpuset_cancel_attach(struct cgroup *cgrp, + struct cgroup_taskset *tset) +{ + mutex_lock(&cpuset_mutex); + cgroup_cs(cgrp)->attach_in_progress--; + mutex_unlock(&cpuset_mutex); } +/* + * Protected by cpuset_mutex. cpus_attach is used only by cpuset_attach() + * but we can't allocate it dynamically there. Define it global and + * allocate from cpuset_init(). + */ +static cpumask_var_t cpus_attach; + static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) { + /* static bufs protected by cpuset_mutex */ + static nodemask_t cpuset_attach_nodemask_from; + static nodemask_t cpuset_attach_nodemask_to; struct mm_struct *mm; struct task_struct *task; struct task_struct *leader = cgroup_taskset_first(tset); @@ -1423,6 +1432,16 @@ static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) struct cpuset *cs = cgroup_cs(cgrp); struct cpuset *oldcs = cgroup_cs(oldcgrp); + mutex_lock(&cpuset_mutex); + + /* prepare for attach */ + if (cs == &top_cpuset) + cpumask_copy(cpus_attach, cpu_possible_mask); + else + guarantee_online_cpus(cs, cpus_attach); + + guarantee_online_mems(cs, &cpuset_attach_nodemask_to); + cgroup_taskset_for_each(task, cgrp, tset) { /* * can_attach beforehand should guarantee that this doesn't @@ -1448,6 +1467,18 @@ static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) &cpuset_attach_nodemask_to); mmput(mm); } + + cs->attach_in_progress--; + + /* + * We may have raced with CPU/memory hotunplug. Trigger hotplug + * propagation if @cs doesn't have any CPU or memory. It will move + * the newly added tasks to the nearest parent which can execute. + */ + if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) + schedule_cpuset_propagate_hotplug(cs); + + mutex_unlock(&cpuset_mutex); } /* The various types of files and directories in a cpuset file system */ @@ -1469,12 +1500,13 @@ typedef enum { static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) { - int retval = 0; struct cpuset *cs = cgroup_cs(cgrp); cpuset_filetype_t type = cft->private; + int retval = -ENODEV; - if (!cgroup_lock_live_group(cgrp)) - return -ENODEV; + mutex_lock(&cpuset_mutex); + if (!is_cpuset_online(cs)) + goto out_unlock; switch (type) { case FILE_CPU_EXCLUSIVE: @@ -1508,18 +1540,20 @@ static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) retval = -EINVAL; break; } - cgroup_unlock(); +out_unlock: + mutex_unlock(&cpuset_mutex); return retval; } static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val) { - int retval = 0; struct cpuset *cs = cgroup_cs(cgrp); cpuset_filetype_t type = cft->private; + int retval = -ENODEV; - if (!cgroup_lock_live_group(cgrp)) - return -ENODEV; + mutex_lock(&cpuset_mutex); + if (!is_cpuset_online(cs)) + goto out_unlock; switch (type) { case FILE_SCHED_RELAX_DOMAIN_LEVEL: @@ -1529,7 +1563,8 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val) retval = -EINVAL; break; } - cgroup_unlock(); +out_unlock: + mutex_unlock(&cpuset_mutex); return retval; } @@ -1539,17 +1574,36 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val) static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft, const char *buf) { - int retval = 0; struct cpuset *cs = cgroup_cs(cgrp); struct cpuset *trialcs; + int retval = -ENODEV; - if (!cgroup_lock_live_group(cgrp)) - return -ENODEV; + /* + * CPU or memory hotunplug may leave @cs w/o any execution + * resources, in which case the hotplug code asynchronously updates + * configuration and transfers all tasks to the nearest ancestor + * which can execute. + * + * As writes to "cpus" or "mems" may restore @cs's execution + * resources, wait for the previously scheduled operations before + * proceeding, so that we don't end up keep removing tasks added + * after execution capability is restored. + * + * Flushing cpuset_hotplug_work is enough to synchronize against + * hotplug hanlding; however, cpuset_attach() may schedule + * propagation work directly. Flush the workqueue too. + */ + flush_work(&cpuset_hotplug_work); + flush_workqueue(cpuset_propagate_hotplug_wq); + + mutex_lock(&cpuset_mutex); + if (!is_cpuset_online(cs)) + goto out_unlock; trialcs = alloc_trial_cpuset(cs); if (!trialcs) { retval = -ENOMEM; - goto out; + goto out_unlock; } switch (cft->private) { @@ -1565,8 +1619,8 @@ static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft, } free_trial_cpuset(trialcs); -out: - cgroup_unlock(); +out_unlock: + mutex_unlock(&cpuset_mutex); return retval; } @@ -1790,15 +1844,12 @@ static struct cftype files[] = { static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont) { - struct cgroup *parent_cg = cont->parent; - struct cgroup *tmp_cg; - struct cpuset *parent, *cs; + struct cpuset *cs; - if (!parent_cg) + if (!cont->parent) return &top_cpuset.css; - parent = cgroup_cs(parent_cg); - cs = kmalloc(sizeof(*cs), GFP_KERNEL); + cs = kzalloc(sizeof(*cs), GFP_KERNEL); if (!cs) return ERR_PTR(-ENOMEM); if (!alloc_cpumask_var(&cs->cpus_allowed, GFP_KERNEL)) { @@ -1806,22 +1857,38 @@ static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont) return ERR_PTR(-ENOMEM); } - cs->flags = 0; - if (is_spread_page(parent)) - set_bit(CS_SPREAD_PAGE, &cs->flags); - if (is_spread_slab(parent)) - set_bit(CS_SPREAD_SLAB, &cs->flags); set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags); cpumask_clear(cs->cpus_allowed); nodes_clear(cs->mems_allowed); fmeter_init(&cs->fmeter); + INIT_WORK(&cs->hotplug_work, cpuset_propagate_hotplug_workfn); cs->relax_domain_level = -1; - cs->parent = parent; + return &cs->css; +} + +static int cpuset_css_online(struct cgroup *cgrp) +{ + struct cpuset *cs = cgroup_cs(cgrp); + struct cpuset *parent = parent_cs(cs); + struct cpuset *tmp_cs; + struct cgroup *pos_cg; + + if (!parent) + return 0; + + mutex_lock(&cpuset_mutex); + + set_bit(CS_ONLINE, &cs->flags); + if (is_spread_page(parent)) + set_bit(CS_SPREAD_PAGE, &cs->flags); + if (is_spread_slab(parent)) + set_bit(CS_SPREAD_SLAB, &cs->flags); + number_of_cpusets++; - if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cont->flags)) - goto skip_clone; + if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags)) + goto out_unlock; /* * Clone @parent's configuration if CGRP_CPUSET_CLONE_CHILDREN is @@ -1836,35 +1903,49 @@ static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont) * changed to grant parent->cpus_allowed-sibling_cpus_exclusive * (and likewise for mems) to the new cgroup. */ - list_for_each_entry(tmp_cg, &parent_cg->children, sibling) { - struct cpuset *tmp_cs = cgroup_cs(tmp_cg); - - if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs)) - goto skip_clone; + rcu_read_lock(); + cpuset_for_each_child(tmp_cs, pos_cg, parent) { + if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs)) { + rcu_read_unlock(); + goto out_unlock; + } } + rcu_read_unlock(); mutex_lock(&callback_mutex); cs->mems_allowed = parent->mems_allowed; cpumask_copy(cs->cpus_allowed, parent->cpus_allowed); mutex_unlock(&callback_mutex); -skip_clone: - return &cs->css; +out_unlock: + mutex_unlock(&cpuset_mutex); + return 0; +} + +static void cpuset_css_offline(struct cgroup *cgrp) +{ + struct cpuset *cs = cgroup_cs(cgrp); + + mutex_lock(&cpuset_mutex); + + if (is_sched_load_balance(cs)) + update_flag(CS_SCHED_LOAD_BALANCE, cs, 0); + + number_of_cpusets--; + clear_bit(CS_ONLINE, &cs->flags); + + mutex_unlock(&cpuset_mutex); } /* * If the cpuset being removed has its flag 'sched_load_balance' * enabled, then simulate turning sched_load_balance off, which - * will call async_rebuild_sched_domains(). + * will call rebuild_sched_domains_locked(). */ static void cpuset_css_free(struct cgroup *cont) { struct cpuset *cs = cgroup_cs(cont); - if (is_sched_load_balance(cs)) - update_flag(CS_SCHED_LOAD_BALANCE, cs, 0); - - number_of_cpusets--; free_cpumask_var(cs->cpus_allowed); kfree(cs); } @@ -1872,8 +1953,11 @@ static void cpuset_css_free(struct cgroup *cont) struct cgroup_subsys cpuset_subsys = { .name = "cpuset", .css_alloc = cpuset_css_alloc, + .css_online = cpuset_css_online, + .css_offline = cpuset_css_offline, .css_free = cpuset_css_free, .can_attach = cpuset_can_attach, + .cancel_attach = cpuset_cancel_attach, .attach = cpuset_attach, .subsys_id = cpuset_subsys_id, .base_cftypes = files, @@ -1911,220 +1995,204 @@ int __init cpuset_init(void) return 0; } -/** - * cpuset_do_move_task - move a given task to another cpuset - * @tsk: pointer to task_struct the task to move - * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner - * - * Called by cgroup_scan_tasks() for each task in a cgroup. - * Return nonzero to stop the walk through the tasks. - */ -static void cpuset_do_move_task(struct task_struct *tsk, - struct cgroup_scanner *scan) -{ - struct cgroup *new_cgroup = scan->data; - - cgroup_attach_task(new_cgroup, tsk); -} - -/** - * move_member_tasks_to_cpuset - move tasks from one cpuset to another - * @from: cpuset in which the tasks currently reside - * @to: cpuset to which the tasks will be moved - * - * Called with cgroup_mutex held - * callback_mutex must not be held, as cpuset_attach() will take it. - * - * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, - * calling callback functions for each. - */ -static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to) -{ - struct cgroup_scanner scan; - - scan.cg = from->css.cgroup; - scan.test_task = NULL; /* select all tasks in cgroup */ - scan.process_task = cpuset_do_move_task; - scan.heap = NULL; - scan.data = to->css.cgroup; - - if (cgroup_scan_tasks(&scan)) - printk(KERN_ERR "move_member_tasks_to_cpuset: " - "cgroup_scan_tasks failed\n"); -} - /* * If CPU and/or memory hotplug handlers, below, unplug any CPUs * or memory nodes, we need to walk over the cpuset hierarchy, * removing that CPU or node from all cpusets. If this removes the * last CPU or node from a cpuset, then move the tasks in the empty * cpuset to its next-highest non-empty parent. - * - * Called with cgroup_mutex held - * callback_mutex must not be held, as cpuset_attach() will take it. */ static void remove_tasks_in_empty_cpuset(struct cpuset *cs) { struct cpuset *parent; /* - * The cgroup's css_sets list is in use if there are tasks - * in the cpuset; the list is empty if there are none; - * the cs->css.refcnt seems always 0. - */ - if (list_empty(&cs->css.cgroup->css_sets)) - return; - - /* * Find its next-highest non-empty parent, (top cpuset * has online cpus, so can't be empty). */ - parent = cs->parent; + parent = parent_cs(cs); while (cpumask_empty(parent->cpus_allowed) || nodes_empty(parent->mems_allowed)) - parent = parent->parent; + parent = parent_cs(parent); - move_member_tasks_to_cpuset(cs, parent); + if (cgroup_transfer_tasks(parent->css.cgroup, cs->css.cgroup)) { + rcu_read_lock(); + printk(KERN_ERR "cpuset: failed to transfer tasks out of empty cpuset %s\n", + cgroup_name(cs->css.cgroup)); + rcu_read_unlock(); + } } -/* - * Helper function to traverse cpusets. - * It can be used to walk the cpuset tree from top to bottom, completing - * one layer before dropping down to the next (thus always processing a - * node before any of its children). +/** + * cpuset_propagate_hotplug_workfn - propagate CPU/memory hotplug to a cpuset + * @cs: cpuset in interest + * + * Compare @cs's cpu and mem masks against top_cpuset and if some have gone + * offline, update @cs accordingly. If @cs ends up with no CPU or memory, + * all its tasks are moved to the nearest ancestor with both resources. */ -static struct cpuset *cpuset_next(struct list_head *queue) +static void cpuset_propagate_hotplug_workfn(struct work_struct *work) { - struct cpuset *cp; - struct cpuset *child; /* scans child cpusets of cp */ - struct cgroup *cont; + static cpumask_t off_cpus; + static nodemask_t off_mems, tmp_mems; + struct cpuset *cs = container_of(work, struct cpuset, hotplug_work); + bool is_empty; - if (list_empty(queue)) - return NULL; + mutex_lock(&cpuset_mutex); + + cpumask_andnot(&off_cpus, cs->cpus_allowed, top_cpuset.cpus_allowed); + nodes_andnot(off_mems, cs->mems_allowed, top_cpuset.mems_allowed); + + /* remove offline cpus from @cs */ + if (!cpumask_empty(&off_cpus)) { + mutex_lock(&callback_mutex); + cpumask_andnot(cs->cpus_allowed, cs->cpus_allowed, &off_cpus); + mutex_unlock(&callback_mutex); + update_tasks_cpumask(cs, NULL); + } - cp = list_first_entry(queue, struct cpuset, stack_list); - list_del(queue->next); - list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { - child = cgroup_cs(cont); - list_add_tail(&child->stack_list, queue); + /* remove offline mems from @cs */ + if (!nodes_empty(off_mems)) { + tmp_mems = cs->mems_allowed; + mutex_lock(&callback_mutex); + nodes_andnot(cs->mems_allowed, cs->mems_allowed, off_mems); + mutex_unlock(&callback_mutex); + update_tasks_nodemask(cs, &tmp_mems, NULL); } - return cp; + is_empty = cpumask_empty(cs->cpus_allowed) || + nodes_empty(cs->mems_allowed); + + mutex_unlock(&cpuset_mutex); + + /* + * If @cs became empty, move tasks to the nearest ancestor with + * execution resources. This is full cgroup operation which will + * also call back into cpuset. Should be done outside any lock. + */ + if (is_empty) + remove_tasks_in_empty_cpuset(cs); + + /* the following may free @cs, should be the last operation */ + css_put(&cs->css); } +/** + * schedule_cpuset_propagate_hotplug - schedule hotplug propagation to a cpuset + * @cs: cpuset of interest + * + * Schedule cpuset_propagate_hotplug_workfn() which will update CPU and + * memory masks according to top_cpuset. + */ +static void schedule_cpuset_propagate_hotplug(struct cpuset *cs) +{ + /* + * Pin @cs. The refcnt will be released when the work item + * finishes executing. + */ + if (!css_tryget(&cs->css)) + return; -/* - * Walk the specified cpuset subtree upon a hotplug operation (CPU/Memory - * online/offline) and update the cpusets accordingly. - * For regular CPU/Mem hotplug, look for empty cpusets; the tasks of such - * cpuset must be moved to a parent cpuset. + /* + * Queue @cs->hotplug_work. If already pending, lose the css ref. + * cpuset_propagate_hotplug_wq is ordered and propagation will + * happen in the order this function is called. + */ + if (!queue_work(cpuset_propagate_hotplug_wq, &cs->hotplug_work)) + css_put(&cs->css); +} + +/** + * cpuset_hotplug_workfn - handle CPU/memory hotunplug for a cpuset * - * Called with cgroup_mutex held. We take callback_mutex to modify - * cpus_allowed and mems_allowed. + * This function is called after either CPU or memory configuration has + * changed and updates cpuset accordingly. The top_cpuset is always + * synchronized to cpu_active_mask and N_MEMORY, which is necessary in + * order to make cpusets transparent (of no affect) on systems that are + * actively using CPU hotplug but making no active use of cpusets. * - * This walk processes the tree from top to bottom, completing one layer - * before dropping down to the next. It always processes a node before - * any of its children. + * Non-root cpusets are only affected by offlining. If any CPUs or memory + * nodes have been taken down, cpuset_propagate_hotplug() is invoked on all + * descendants. * - * In the case of memory hot-unplug, it will remove nodes from N_MEMORY - * if all present pages from a node are offlined. + * Note that CPU offlining during suspend is ignored. We don't modify + * cpusets across suspend/resume cycles at all. */ -static void -scan_cpusets_upon_hotplug(struct cpuset *root, enum hotplug_event event) +static void cpuset_hotplug_workfn(struct work_struct *work) { - LIST_HEAD(queue); - struct cpuset *cp; /* scans cpusets being updated */ - static nodemask_t oldmems; /* protected by cgroup_mutex */ + static cpumask_t new_cpus, tmp_cpus; + static nodemask_t new_mems, tmp_mems; + bool cpus_updated, mems_updated; + bool cpus_offlined, mems_offlined; - list_add_tail((struct list_head *)&root->stack_list, &queue); + mutex_lock(&cpuset_mutex); - switch (event) { - case CPUSET_CPU_OFFLINE: - while ((cp = cpuset_next(&queue)) != NULL) { + /* fetch the available cpus/mems and find out which changed how */ + cpumask_copy(&new_cpus, cpu_active_mask); + new_mems = node_states[N_MEMORY]; - /* Continue past cpusets with all cpus online */ - if (cpumask_subset(cp->cpus_allowed, cpu_active_mask)) - continue; + cpus_updated = !cpumask_equal(top_cpuset.cpus_allowed, &new_cpus); + cpus_offlined = cpumask_andnot(&tmp_cpus, top_cpuset.cpus_allowed, + &new_cpus); - /* Remove offline cpus from this cpuset. */ - mutex_lock(&callback_mutex); - cpumask_and(cp->cpus_allowed, cp->cpus_allowed, - cpu_active_mask); - mutex_unlock(&callback_mutex); + mems_updated = !nodes_equal(top_cpuset.mems_allowed, new_mems); + nodes_andnot(tmp_mems, top_cpuset.mems_allowed, new_mems); + mems_offlined = !nodes_empty(tmp_mems); - /* Move tasks from the empty cpuset to a parent */ - if (cpumask_empty(cp->cpus_allowed)) - remove_tasks_in_empty_cpuset(cp); - else - update_tasks_cpumask(cp, NULL); - } - break; + /* synchronize cpus_allowed to cpu_active_mask */ + if (cpus_updated) { + mutex_lock(&callback_mutex); + cpumask_copy(top_cpuset.cpus_allowed, &new_cpus); + mutex_unlock(&callback_mutex); + /* we don't mess with cpumasks of tasks in top_cpuset */ + } - case CPUSET_MEM_OFFLINE: - while ((cp = cpuset_next(&queue)) != NULL) { + /* synchronize mems_allowed to N_MEMORY */ + if (mems_updated) { + tmp_mems = top_cpuset.mems_allowed; + mutex_lock(&callback_mutex); + top_cpuset.mems_allowed = new_mems; + mutex_unlock(&callback_mutex); + update_tasks_nodemask(&top_cpuset, &tmp_mems, NULL); + } - /* Continue past cpusets with all mems online */ - if (nodes_subset(cp->mems_allowed, - node_states[N_MEMORY])) - continue; + /* if cpus or mems went down, we need to propagate to descendants */ + if (cpus_offlined || mems_offlined) { + struct cpuset *cs; + struct cgroup *pos_cgrp; - oldmems = cp->mems_allowed; + rcu_read_lock(); + cpuset_for_each_descendant_pre(cs, pos_cgrp, &top_cpuset) + schedule_cpuset_propagate_hotplug(cs); + rcu_read_unlock(); + } - /* Remove offline mems from this cpuset. */ - mutex_lock(&callback_mutex); - nodes_and(cp->mems_allowed, cp->mems_allowed, - node_states[N_MEMORY]); - mutex_unlock(&callback_mutex); + mutex_unlock(&cpuset_mutex); - /* Move tasks from the empty cpuset to a parent */ - if (nodes_empty(cp->mems_allowed)) - remove_tasks_in_empty_cpuset(cp); - else - update_tasks_nodemask(cp, &oldmems, NULL); - } - } + /* wait for propagations to finish */ + flush_workqueue(cpuset_propagate_hotplug_wq); + + /* rebuild sched domains if cpus_allowed has changed */ + if (cpus_updated) + rebuild_sched_domains(); } -/* - * The top_cpuset tracks what CPUs and Memory Nodes are online, - * period. This is necessary in order to make cpusets transparent - * (of no affect) on systems that are actively using CPU hotplug - * but making no active use of cpusets. - * - * The only exception to this is suspend/resume, where we don't - * modify cpusets at all. - * - * This routine ensures that top_cpuset.cpus_allowed tracks - * cpu_active_mask on each CPU hotplug (cpuhp) event. - * - * Called within get_online_cpus(). Needs to call cgroup_lock() - * before calling generate_sched_domains(). - * - * @cpu_online: Indicates whether this is a CPU online event (true) or - * a CPU offline event (false). - */ void cpuset_update_active_cpus(bool cpu_online) { - struct sched_domain_attr *attr; - cpumask_var_t *doms; - int ndoms; - - cgroup_lock(); - mutex_lock(&callback_mutex); - cpumask_copy(top_cpuset.cpus_allowed, cpu_active_mask); - mutex_unlock(&callback_mutex); - - if (!cpu_online) - scan_cpusets_upon_hotplug(&top_cpuset, CPUSET_CPU_OFFLINE); - - ndoms = generate_sched_domains(&doms, &attr); - cgroup_unlock(); - - /* Have scheduler rebuild the domains */ - partition_sched_domains(ndoms, doms, attr); + /* + * We're inside cpu hotplug critical region which usually nests + * inside cgroup synchronization. Bounce actual hotplug processing + * to a work item to avoid reverse locking order. + * + * We still need to do partition_sched_domains() synchronously; + * otherwise, the scheduler will get confused and put tasks to the + * dead CPU. Fall back to the default single domain. + * cpuset_hotplug_workfn() will rebuild it as necessary. + */ + partition_sched_domains(1, NULL, NULL); + schedule_work(&cpuset_hotplug_work); } -#ifdef CONFIG_MEMORY_HOTPLUG /* * Keep top_cpuset.mems_allowed tracking node_states[N_MEMORY]. * Call this routine anytime after node_states[N_MEMORY] changes. @@ -2133,48 +2201,30 @@ void cpuset_update_active_cpus(bool cpu_online) static int cpuset_track_online_nodes(struct notifier_block *self, unsigned long action, void *arg) { - static nodemask_t oldmems; /* protected by cgroup_mutex */ - - cgroup_lock(); - switch (action) { - case MEM_ONLINE: - oldmems = top_cpuset.mems_allowed; - mutex_lock(&callback_mutex); - top_cpuset.mems_allowed = node_states[N_MEMORY]; - mutex_unlock(&callback_mutex); - update_tasks_nodemask(&top_cpuset, &oldmems, NULL); - break; - case MEM_OFFLINE: - /* - * needn't update top_cpuset.mems_allowed explicitly because - * scan_cpusets_upon_hotplug() will update it. - */ - scan_cpusets_upon_hotplug(&top_cpuset, CPUSET_MEM_OFFLINE); - break; - default: - break; - } - cgroup_unlock(); - + schedule_work(&cpuset_hotplug_work); return NOTIFY_OK; } -#endif + +static struct notifier_block cpuset_track_online_nodes_nb = { + .notifier_call = cpuset_track_online_nodes, + .priority = 10, /* ??! */ +}; /** * cpuset_init_smp - initialize cpus_allowed * * Description: Finish top cpuset after cpu, node maps are initialized - **/ - + */ void __init cpuset_init_smp(void) { cpumask_copy(top_cpuset.cpus_allowed, cpu_active_mask); top_cpuset.mems_allowed = node_states[N_MEMORY]; - hotplug_memory_notifier(cpuset_track_online_nodes, 10); + register_hotmemory_notifier(&cpuset_track_online_nodes_nb); - cpuset_wq = create_singlethread_workqueue("cpuset"); - BUG_ON(!cpuset_wq); + cpuset_propagate_hotplug_wq = + alloc_ordered_workqueue("cpuset_hotplug", 0); + BUG_ON(!cpuset_propagate_hotplug_wq); } /** @@ -2273,8 +2323,8 @@ int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask) */ static const struct cpuset *nearest_hardwall_ancestor(const struct cpuset *cs) { - while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && cs->parent) - cs = cs->parent; + while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && parent_cs(cs)) + cs = parent_cs(cs); return cs; } @@ -2412,17 +2462,6 @@ int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask) } /** - * cpuset_unlock - release lock on cpuset changes - * - * Undo the lock taken in a previous cpuset_lock() call. - */ - -void cpuset_unlock(void) -{ - mutex_unlock(&callback_mutex); -} - -/** * cpuset_mem_spread_node() - On which node to begin search for a file page * cpuset_slab_spread_node() - On which node to begin search for a slab page * @@ -2497,6 +2536,8 @@ int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, return nodes_intersects(tsk1->mems_allowed, tsk2->mems_allowed); } +#define CPUSET_NODELIST_LEN (256) + /** * cpuset_print_task_mems_allowed - prints task's cpuset and mems_allowed * @task: pointer to task_struct of some task. @@ -2507,17 +2548,22 @@ int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, */ void cpuset_print_task_mems_allowed(struct task_struct *tsk) { - struct dentry *dentry; + /* Statically allocated to prevent using excess stack. */ + static char cpuset_nodelist[CPUSET_NODELIST_LEN]; + static DEFINE_SPINLOCK(cpuset_buffer_lock); + + struct cgroup *cgrp = task_cs(tsk)->css.cgroup; - dentry = task_cs(tsk)->css.cgroup->dentry; + rcu_read_lock(); spin_lock(&cpuset_buffer_lock); - snprintf(cpuset_name, CPUSET_NAME_LEN, - dentry ? (const char *)dentry->d_name.name : "/"); + nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN, tsk->mems_allowed); printk(KERN_INFO "%s cpuset=%s mems_allowed=%s\n", - tsk->comm, cpuset_name, cpuset_nodelist); + tsk->comm, cgroup_name(cgrp), cpuset_nodelist); + spin_unlock(&cpuset_buffer_lock); + rcu_read_unlock(); } /* @@ -2560,10 +2606,10 @@ void __cpuset_memory_pressure_bump(void) * - Used for /proc/<pid>/cpuset. * - No need to task_lock(tsk) on this tsk->cpuset reference, as it * doesn't really matter if tsk->cpuset changes after we read it, - * and we take cgroup_mutex, keeping cpuset_attach() from changing it + * and we take cpuset_mutex, keeping cpuset_attach() from changing it * anyway. */ -static int proc_cpuset_show(struct seq_file *m, void *unused_v) +int proc_cpuset_show(struct seq_file *m, void *unused_v) { struct pid *pid; struct task_struct *tsk; @@ -2582,35 +2628,21 @@ static int proc_cpuset_show(struct seq_file *m, void *unused_v) if (!tsk) goto out_free; - retval = -EINVAL; - cgroup_lock(); + rcu_read_lock(); css = task_subsys_state(tsk, cpuset_subsys_id); retval = cgroup_path(css->cgroup, buf, PAGE_SIZE); + rcu_read_unlock(); if (retval < 0) - goto out_unlock; + goto out_put_task; seq_puts(m, buf); seq_putc(m, '\n'); -out_unlock: - cgroup_unlock(); +out_put_task: put_task_struct(tsk); out_free: kfree(buf); out: return retval; } - -static int cpuset_open(struct inode *inode, struct file *file) -{ - struct pid *pid = PROC_I(inode)->pid; - return single_open(file, proc_cpuset_show, pid); -} - -const struct file_operations proc_cpuset_operations = { - .open = cpuset_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; #endif /* CONFIG_PROC_PID_CPUSET */ /* Display task mems_allowed in /proc/<pid>/status file. */ diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 9a61738cefc8..0506d447aed2 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -29,6 +29,7 @@ */ #include <linux/pid_namespace.h> #include <linux/clocksource.h> +#include <linux/serial_core.h> #include <linux/interrupt.h> #include <linux/spinlock.h> #include <linux/console.h> @@ -774,7 +775,7 @@ static void sysrq_handle_dbg(int key) static struct sysrq_key_op sysrq_dbg_op = { .handler = sysrq_handle_dbg, - .help_msg = "debug(G)", + .help_msg = "debug(g)", .action_msg = "DEBUG", }; #endif diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h index 3494c28a7e7a..2235967e78b0 100644 --- a/kernel/debug/debug_core.h +++ b/kernel/debug/debug_core.h @@ -72,6 +72,8 @@ extern int dbg_kdb_mode; #ifdef CONFIG_KGDB_KDB extern int kdb_stub(struct kgdb_state *ks); extern int kdb_parse(const char *cmdstr); +extern int kdb_common_init_state(struct kgdb_state *ks); +extern int kdb_common_deinit_state(void); #else /* ! CONFIG_KGDB_KDB */ static inline int kdb_stub(struct kgdb_state *ks) { diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c index ce615e064482..19d9a578c753 100644 --- a/kernel/debug/gdbstub.c +++ b/kernel/debug/gdbstub.c @@ -31,6 +31,7 @@ #include <linux/kernel.h> #include <linux/kgdb.h> #include <linux/kdb.h> +#include <linux/serial_core.h> #include <linux/reboot.h> #include <linux/uaccess.h> #include <asm/cacheflush.h> @@ -782,7 +783,10 @@ static void gdb_cmd_query(struct kgdb_state *ks) len = len / 2; remcom_out_buffer[len++] = 0; + kdb_common_init_state(ks); kdb_parse(remcom_out_buffer); + kdb_common_deinit_state(); + strcpy(remcom_out_buffer, "OK"); } break; diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c index 8418c2f8ec5d..70a504601dc3 100644 --- a/kernel/debug/kdb/kdb_bp.c +++ b/kernel/debug/kdb/kdb_bp.c @@ -486,11 +486,9 @@ static int kdb_bc(int argc, const char **argv) /* * kdb_ss * - * Process the 'ss' (Single Step) and 'ssb' (Single Step to Branch) - * commands. + * Process the 'ss' (Single Step) command. * * ss - * ssb * * Parameters: * argc Argument count @@ -498,35 +496,23 @@ static int kdb_bc(int argc, const char **argv) * Outputs: * None. * Returns: - * KDB_CMD_SS[B] for success, a kdb error if failure. + * KDB_CMD_SS for success, a kdb error if failure. * Locking: * None. * Remarks: * * Set the arch specific option to trigger a debug trap after the next * instruction. - * - * For 'ssb', set the trace flag in the debug trap handler - * after printing the current insn and return directly without - * invoking the kdb command processor, until a branch instruction - * is encountered. */ static int kdb_ss(int argc, const char **argv) { - int ssb = 0; - - ssb = (strcmp(argv[0], "ssb") == 0); if (argc != 0) return KDB_ARGCOUNT; /* * Set trace flag and go. */ KDB_STATE_SET(DOING_SS); - if (ssb) { - KDB_STATE_SET(DOING_SSB); - return KDB_CMD_SSB; - } return KDB_CMD_SS; } @@ -561,8 +547,6 @@ void __init kdb_initbptab(void) kdb_register_repeat("ss", kdb_ss, "", "Single Step", 1, KDB_REPEAT_NO_ARGS); - kdb_register_repeat("ssb", kdb_ss, "", - "Single step to branch/call", 0, KDB_REPEAT_NO_ARGS); /* * Architecture dependent initialization. */ diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c index be7b33b73d30..328d18ef31e4 100644 --- a/kernel/debug/kdb/kdb_debugger.c +++ b/kernel/debug/kdb/kdb_debugger.c @@ -34,6 +34,22 @@ EXPORT_SYMBOL_GPL(kdb_poll_idx); static struct kgdb_state *kdb_ks; +int kdb_common_init_state(struct kgdb_state *ks) +{ + kdb_initial_cpu = atomic_read(&kgdb_active); + kdb_current_task = kgdb_info[ks->cpu].task; + kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo; + return 0; +} + +int kdb_common_deinit_state(void) +{ + kdb_initial_cpu = -1; + kdb_current_task = NULL; + kdb_current_regs = NULL; + return 0; +} + int kdb_stub(struct kgdb_state *ks) { int error = 0; @@ -94,13 +110,10 @@ int kdb_stub(struct kgdb_state *ks) } /* Set initial kdb state variables */ KDB_STATE_CLEAR(KGDB_TRANS); - kdb_initial_cpu = atomic_read(&kgdb_active); - kdb_current_task = kgdb_info[ks->cpu].task; - kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo; + kdb_common_init_state(ks); /* Remove any breakpoints as needed by kdb and clear single step */ kdb_bp_remove(); KDB_STATE_CLEAR(DOING_SS); - KDB_STATE_CLEAR(DOING_SSB); KDB_STATE_SET(PAGER); /* zero out any offline cpu data */ for_each_present_cpu(i) { @@ -125,9 +138,7 @@ int kdb_stub(struct kgdb_state *ks) * Upon exit from the kdb main loop setup break points and restart * the system based on the requested continue state */ - kdb_initial_cpu = -1; - kdb_current_task = NULL; - kdb_current_regs = NULL; + kdb_common_deinit_state(); KDB_STATE_CLEAR(PAGER); kdbnearsym_cleanup(); if (error == KDB_CMD_KGDB) { diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 8875254120b6..00eb8f7fbf41 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -124,7 +124,7 @@ static kdbmsg_t kdbmsgs[] = { }; #undef KDBMSG -static const int __nkdb_err = sizeof(kdbmsgs) / sizeof(kdbmsg_t); +static const int __nkdb_err = ARRAY_SIZE(kdbmsgs); /* @@ -175,7 +175,7 @@ static char *__env[] = { (char *)0, }; -static const int __nenv = (sizeof(__env) / sizeof(char *)); +static const int __nenv = ARRAY_SIZE(__env); struct task_struct *kdb_curr_task(int cpu) { @@ -681,34 +681,50 @@ static int kdb_defcmd(int argc, const char **argv) } if (argc != 3) return KDB_ARGCOUNT; - defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set), - GFP_KDB); - if (!defcmd_set) { - kdb_printf("Could not allocate new defcmd_set entry for %s\n", - argv[1]); - defcmd_set = save_defcmd_set; + if (in_dbg_master()) { + kdb_printf("Command only available during kdb_init()\n"); return KDB_NOTIMP; } + defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set), + GFP_KDB); + if (!defcmd_set) + goto fail_defcmd; memcpy(defcmd_set, save_defcmd_set, defcmd_set_count * sizeof(*defcmd_set)); - kfree(save_defcmd_set); s = defcmd_set + defcmd_set_count; memset(s, 0, sizeof(*s)); s->usable = 1; s->name = kdb_strdup(argv[1], GFP_KDB); + if (!s->name) + goto fail_name; s->usage = kdb_strdup(argv[2], GFP_KDB); + if (!s->usage) + goto fail_usage; s->help = kdb_strdup(argv[3], GFP_KDB); + if (!s->help) + goto fail_help; if (s->usage[0] == '"') { - strcpy(s->usage, s->usage+1); + strcpy(s->usage, argv[2]+1); s->usage[strlen(s->usage)-1] = '\0'; } if (s->help[0] == '"') { - strcpy(s->help, s->help+1); + strcpy(s->help, argv[3]+1); s->help[strlen(s->help)-1] = '\0'; } ++defcmd_set_count; defcmd_in_progress = 1; + kfree(save_defcmd_set); return 0; +fail_help: + kfree(s->usage); +fail_usage: + kfree(s->name); +fail_name: + kfree(defcmd_set); +fail_defcmd: + kdb_printf("Could not allocate new defcmd_set entry for %s\n", argv[1]); + defcmd_set = save_defcmd_set; + return KDB_NOTIMP; } /* @@ -1112,7 +1128,6 @@ void kdb_set_current_task(struct task_struct *p) * KDB_CMD_GO User typed 'go'. * KDB_CMD_CPU User switched to another cpu. * KDB_CMD_SS Single step. - * KDB_CMD_SSB Single step until branch. */ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs, kdb_dbtrap_t db_result) @@ -1151,14 +1166,6 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs, kdb_printf("due to Debug @ " kdb_machreg_fmt "\n", instruction_pointer(regs)); break; - case KDB_DB_SSB: - /* - * In the midst of ssb command. Just return. - */ - KDB_DEBUG_STATE("kdb_local 3", reason); - return KDB_CMD_SSB; /* Continue with SSB command */ - - break; case KDB_DB_SS: break; case KDB_DB_SSBPT: @@ -1281,7 +1288,6 @@ do_full_getstr: if (diag == KDB_CMD_GO || diag == KDB_CMD_CPU || diag == KDB_CMD_SS - || diag == KDB_CMD_SSB || diag == KDB_CMD_KGDB) break; @@ -1368,12 +1374,6 @@ int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error, break; } - if (result == KDB_CMD_SSB) { - KDB_STATE_SET(DOING_SS); - KDB_STATE_SET(DOING_SSB); - break; - } - if (result == KDB_CMD_KGDB) { if (!KDB_STATE(DOING_KGDB)) kdb_printf("Entering please attach debugger " @@ -2350,69 +2350,6 @@ static int kdb_pid(int argc, const char **argv) return 0; } -/* - * kdb_ll - This function implements the 'll' command which follows a - * linked list and executes an arbitrary command for each - * element. - */ -static int kdb_ll(int argc, const char **argv) -{ - int diag = 0; - unsigned long addr; - long offset = 0; - unsigned long va; - unsigned long linkoffset; - int nextarg; - const char *command; - - if (argc != 3) - return KDB_ARGCOUNT; - - nextarg = 1; - diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL); - if (diag) - return diag; - - diag = kdbgetularg(argv[2], &linkoffset); - if (diag) - return diag; - - /* - * Using the starting address as - * the first element in the list, and assuming that - * the list ends with a null pointer. - */ - - va = addr; - command = kdb_strdup(argv[3], GFP_KDB); - if (!command) { - kdb_printf("%s: cannot duplicate command\n", __func__); - return 0; - } - /* Recursive use of kdb_parse, do not use argv after this point */ - argv = NULL; - - while (va) { - char buf[80]; - - if (KDB_FLAG(CMD_INTERRUPT)) - goto out; - - sprintf(buf, "%s " kdb_machreg_fmt "\n", command, va); - diag = kdb_parse(buf); - if (diag) - goto out; - - addr = va + linkoffset; - if (kdb_getword(&va, addr, sizeof(va))) - goto out; - } - -out: - kfree(command); - return diag; -} - static int kdb_kgdb(int argc, const char **argv) { return KDB_CMD_KGDB; @@ -2430,11 +2367,15 @@ static int kdb_help(int argc, const char **argv) kdb_printf("-----------------------------" "-----------------------------\n"); for_each_kdbcmd(kt, i) { - if (kt->cmd_name) - kdb_printf("%-15.15s %-20.20s %s\n", kt->cmd_name, - kt->cmd_usage, kt->cmd_help); + char *space = ""; if (KDB_FLAG(CMD_INTERRUPT)) return 0; + if (!kt->cmd_name) + continue; + if (strlen(kt->cmd_usage) > 20) + space = "\n "; + kdb_printf("%-15.15s %-20s%s%s\n", kt->cmd_name, + kt->cmd_usage, space, kt->cmd_help); } return 0; } @@ -2739,7 +2680,7 @@ int kdb_register_repeat(char *cmd, (kdb_max_commands - KDB_BASE_CMD_MAX) * sizeof(*new)); kfree(kdb_commands); } - memset(new + kdb_max_commands, 0, + memset(new + kdb_max_commands - KDB_BASE_CMD_MAX, 0, kdb_command_extend * sizeof(*new)); kdb_commands = new; kp = kdb_commands + kdb_max_commands - KDB_BASE_CMD_MAX; @@ -2843,15 +2784,13 @@ static void __init kdb_inittab(void) "Stack traceback", 1, KDB_REPEAT_NONE); kdb_register_repeat("btp", kdb_bt, "<pid>", "Display stack for process <pid>", 0, KDB_REPEAT_NONE); - kdb_register_repeat("bta", kdb_bt, "[DRSTCZEUIMA]", - "Display stack all processes", 0, KDB_REPEAT_NONE); + kdb_register_repeat("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]", + "Backtrace all processes matching state flag", 0, KDB_REPEAT_NONE); kdb_register_repeat("btc", kdb_bt, "", "Backtrace current process on each cpu", 0, KDB_REPEAT_NONE); kdb_register_repeat("btt", kdb_bt, "<vaddr>", "Backtrace process given its struct task address", 0, KDB_REPEAT_NONE); - kdb_register_repeat("ll", kdb_ll, "<first-element> <linkoffset> <cmd>", - "Execute cmd for each element in linked list", 0, KDB_REPEAT_NONE); kdb_register_repeat("env", kdb_env, "", "Show environment variables", 0, KDB_REPEAT_NONE); kdb_register_repeat("set", kdb_set, "", diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h index 392ec6a25844..7afd3c8c41d5 100644 --- a/kernel/debug/kdb/kdb_private.h +++ b/kernel/debug/kdb/kdb_private.h @@ -19,7 +19,6 @@ #define KDB_CMD_GO (-1001) #define KDB_CMD_CPU (-1002) #define KDB_CMD_SS (-1003) -#define KDB_CMD_SSB (-1004) #define KDB_CMD_KGDB (-1005) /* Internal debug flags */ @@ -125,8 +124,6 @@ extern int kdb_state; * kdb control */ #define KDB_STATE_HOLD_CPU 0x00000010 /* Hold this cpu inside kdb */ #define KDB_STATE_DOING_SS 0x00000020 /* Doing ss command */ -#define KDB_STATE_DOING_SSB 0x00000040 /* Doing ssb command, - * DOING_SS is also set */ #define KDB_STATE_SSBPT 0x00000080 /* Install breakpoint * after one ss, independent of * DOING_SS */ @@ -191,7 +188,6 @@ extern void kdb_bp_remove(void); typedef enum { KDB_DB_BPT, /* Breakpoint */ KDB_DB_SS, /* Single-step trap */ - KDB_DB_SSB, /* Single step to branch */ KDB_DB_SSBPT, /* Single step over breakpoint */ KDB_DB_NOBPT /* Spurious breakpoint */ } kdb_dbtrap_t; diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 418b3f7053aa..d473988c1d0b 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -106,6 +106,7 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) unsigned long long t2, t3; unsigned long flags; struct timespec ts; + cputime_t utime, stime, stimescaled, utimescaled; /* Though tsk->delays accessed later, early exit avoids * unnecessary returning of other data @@ -114,12 +115,14 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) goto done; tmp = (s64)d->cpu_run_real_total; - cputime_to_timespec(tsk->utime + tsk->stime, &ts); + task_cputime(tsk, &utime, &stime); + cputime_to_timespec(utime + stime, &ts); tmp += timespec_to_ns(&ts); d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp; tmp = (s64)d->cpu_scaled_run_real_total; - cputime_to_timespec(tsk->utimescaled + tsk->stimescaled, &ts); + task_cputime_scaled(tsk, &utimescaled, &stimescaled); + cputime_to_timespec(utimescaled + stimescaled, &ts); tmp += timespec_to_ns(&ts); d->cpu_scaled_run_real_total = (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp; diff --git a/kernel/events/core.c b/kernel/events/core.c index 7b6646a8c067..6b41c1899a8b 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -18,6 +18,7 @@ #include <linux/poll.h> #include <linux/slab.h> #include <linux/hash.h> +#include <linux/tick.h> #include <linux/sysfs.h> #include <linux/dcache.h> #include <linux/percpu.h> @@ -37,6 +38,7 @@ #include <linux/ftrace_event.h> #include <linux/hw_breakpoint.h> #include <linux/mm_types.h> +#include <linux/cgroup.h> #include "internal.h" @@ -234,6 +236,20 @@ static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, #ifdef CONFIG_CGROUP_PERF /* + * perf_cgroup_info keeps track of time_enabled for a cgroup. + * This is a per-cpu dynamically allocated data structure. + */ +struct perf_cgroup_info { + u64 time; + u64 timestamp; +}; + +struct perf_cgroup { + struct cgroup_subsys_state css; + struct perf_cgroup_info __percpu *info; +}; + +/* * Must ensure cgroup is pinned (css_get) before calling * this function. In other words, we cannot call this function * if there is no cgroup event for the current CPU context. @@ -251,7 +267,22 @@ perf_cgroup_match(struct perf_event *event) struct perf_event_context *ctx = event->ctx; struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); - return !event->cgrp || event->cgrp == cpuctx->cgrp; + /* @event doesn't care about cgroup */ + if (!event->cgrp) + return true; + + /* wants specific cgroup scope but @cpuctx isn't associated with any */ + if (!cpuctx->cgrp) + return false; + + /* + * Cgroup scoping is recursive. An event enabled for a cgroup is + * also enabled for all its descendant cgroups. If @cpuctx's + * cgroup is a descendant of @event's (the test covers identity + * case), it's a match. + */ + return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, + event->cgrp->css.cgroup); } static inline bool perf_tryget_cgroup(struct perf_event *event) @@ -655,8 +686,12 @@ static void perf_pmu_rotate_start(struct pmu *pmu) WARN_ON(!irqs_disabled()); - if (list_empty(&cpuctx->rotation_list)) + if (list_empty(&cpuctx->rotation_list)) { + int was_empty = list_empty(head); list_add(&cpuctx->rotation_list, head); + if (was_empty) + tick_nohz_full_kick(); + } } static void get_ctx(struct perf_event_context *ctx) @@ -961,9 +996,15 @@ static void perf_event__header_size(struct perf_event *event) if (sample_type & PERF_SAMPLE_PERIOD) size += sizeof(data->period); + if (sample_type & PERF_SAMPLE_WEIGHT) + size += sizeof(data->weight); + if (sample_type & PERF_SAMPLE_READ) size += event->read_size; + if (sample_type & PERF_SAMPLE_DATA_SRC) + size += sizeof(data->data_src.val); + event->header_size = size; } @@ -2555,6 +2596,16 @@ done: list_del_init(&cpuctx->rotation_list); } +#ifdef CONFIG_NO_HZ_FULL +bool perf_event_can_stop_tick(void) +{ + if (list_empty(&__get_cpu_var(rotation_list))) + return true; + else + return false; +} +#endif + void perf_event_task_tick(void) { struct list_head *head = &__get_cpu_var(rotation_list); @@ -3691,7 +3742,7 @@ unlock: static int perf_fasync(int fd, struct file *filp, int on) { - struct inode *inode = filp->f_path.dentry->d_inode; + struct inode *inode = file_inode(filp); struct perf_event *event = filp->private_data; int retval; @@ -4178,6 +4229,12 @@ void perf_output_sample(struct perf_output_handle *handle, perf_output_sample_ustack(handle, data->stack_user_size, data->regs_user.regs); + + if (sample_type & PERF_SAMPLE_WEIGHT) + perf_output_put(handle, data->weight); + + if (sample_type & PERF_SAMPLE_DATA_SRC) + perf_output_put(handle, data->data_src.val); } void perf_prepare_sample(struct perf_event_header *header, @@ -4434,12 +4491,15 @@ static void perf_event_task_event(struct perf_task_event *task_event) if (ctxn < 0) goto next; ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); + if (ctx) + perf_event_task_ctx(ctx, task_event); } - if (ctx) - perf_event_task_ctx(ctx, task_event); next: put_cpu_ptr(pmu->pmu_cpu_context); } + if (task_event->task_ctx) + perf_event_task_ctx(task_event->task_ctx, task_event); + rcu_read_unlock(); } @@ -4593,6 +4653,7 @@ void perf_event_comm(struct task_struct *task) struct perf_event_context *ctx; int ctxn; + rcu_read_lock(); for_each_task_context_nr(ctxn) { ctx = task->perf_event_ctxp[ctxn]; if (!ctx) @@ -4600,6 +4661,7 @@ void perf_event_comm(struct task_struct *task) perf_event_enable_on_exec(ctx); } + rcu_read_unlock(); if (!atomic_read(&nr_comm_events)) return; @@ -4734,7 +4796,8 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) } else { if (arch_vma_name(mmap_event->vma)) { name = strncpy(tmp, arch_vma_name(mmap_event->vma), - sizeof(tmp)); + sizeof(tmp) - 1); + tmp[sizeof(tmp) - 1] = '\0'; goto got_name; } @@ -4761,6 +4824,9 @@ got_name: mmap_event->file_name = name; mmap_event->file_size = size; + if (!(vma->vm_flags & VM_EXEC)) + mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; + mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; rcu_read_lock(); @@ -5126,7 +5192,6 @@ static void do_perf_sw_event(enum perf_type_id type, u32 event_id, { struct swevent_htable *swhash = &__get_cpu_var(swevent_htable); struct perf_event *event; - struct hlist_node *node; struct hlist_head *head; rcu_read_lock(); @@ -5134,7 +5199,7 @@ static void do_perf_sw_event(enum perf_type_id type, u32 event_id, if (!head) goto end; - hlist_for_each_entry_rcu(event, node, head, hlist_entry) { + hlist_for_each_entry_rcu(event, head, hlist_entry) { if (perf_swevent_match(event, type, event_id, data, regs)) perf_swevent_event(event, nr, data, regs); } @@ -5328,7 +5393,7 @@ static void sw_perf_event_destroy(struct perf_event *event) static int perf_swevent_init(struct perf_event *event) { - int event_id = event->attr.config; + u64 event_id = event->attr.config; if (event->attr.type != PERF_TYPE_SOFTWARE) return -ENOENT; @@ -5419,7 +5484,6 @@ void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, { struct perf_sample_data data; struct perf_event *event; - struct hlist_node *node; struct perf_raw_record raw = { .size = entry_size, @@ -5429,7 +5493,7 @@ void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, perf_sample_data_init(&data, addr, 0); data.raw = &raw; - hlist_for_each_entry_rcu(event, node, head, hlist_entry) { + hlist_for_each_entry_rcu(event, head, hlist_entry) { if (perf_tp_event_match(event, &data, regs)) perf_swevent_event(event, count, &data, regs); } @@ -5649,6 +5713,7 @@ static void perf_swevent_init_hrtimer(struct perf_event *event) event->attr.sample_period = NSEC_PER_SEC / freq; hwc->sample_period = event->attr.sample_period; local64_set(&hwc->period_left, hwc->sample_period); + hwc->last_period = hwc->sample_period; event->attr.freq = 0; } } @@ -5965,13 +6030,9 @@ int perf_pmu_register(struct pmu *pmu, char *name, int type) pmu->name = name; if (type < 0) { - int err = idr_pre_get(&pmu_idr, GFP_KERNEL); - if (!err) - goto free_pdc; - - err = idr_get_new_above(&pmu_idr, pmu, PERF_TYPE_MAX, &type); - if (err) { - ret = err; + type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL); + if (type < 0) { + ret = type; goto free_pdc; } } @@ -5988,6 +6049,7 @@ skip_type: if (pmu->pmu_cpu_context) goto got_cpu_context; + ret = -ENOMEM; pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); if (!pmu->pmu_cpu_context) goto free_dev; @@ -6171,11 +6233,14 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, if (task) { event->attach_state = PERF_ATTACH_TASK; + + if (attr->type == PERF_TYPE_TRACEPOINT) + event->hw.tp_target = task; #ifdef CONFIG_HAVE_HW_BREAKPOINT /* * hw_breakpoint is a bit difficult here.. */ - if (attr->type == PERF_TYPE_BREAKPOINT) + else if (attr->type == PERF_TYPE_BREAKPOINT) event->hw.bp_target = task; #endif } @@ -7512,12 +7577,5 @@ struct cgroup_subsys perf_subsys = { .css_free = perf_cgroup_css_free, .exit = perf_cgroup_exit, .attach = perf_cgroup_attach, - - /* - * perf_event cgroup doesn't handle nesting correctly. - * ctx->nr_cgroups adjustments should be propagated through the - * cgroup hierarchy. Fix it and remove the following. - */ - .broken_hierarchy = true, }; #endif /* CONFIG_CGROUP_PERF */ diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index fe8a916507ed..a64f8aeb5c1f 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -676,7 +676,7 @@ int __init init_hw_breakpoint(void) err_alloc: for_each_possible_cpu(err_cpu) { for (i = 0; i < TYPE_MAX; i++) - kfree(per_cpu(nr_task_bp_pinned[i], cpu)); + kfree(per_cpu(nr_task_bp_pinned[i], err_cpu)); if (err_cpu == cpu) break; } diff --git a/kernel/events/internal.h b/kernel/events/internal.h index d56a64c99a8b..eb675c4d59df 100644 --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -16,7 +16,7 @@ struct ring_buffer { int page_order; /* allocation order */ #endif int nr_pages; /* nr of data pages */ - int writable; /* are we writable */ + int overwrite; /* can overwrite itself */ atomic_t poll; /* POLL_ for wakeups */ diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index 23cb34ff3973..cd55144270b5 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -18,12 +18,24 @@ static bool perf_output_space(struct ring_buffer *rb, unsigned long tail, unsigned long offset, unsigned long head) { - unsigned long mask; + unsigned long sz = perf_data_size(rb); + unsigned long mask = sz - 1; - if (!rb->writable) + /* + * check if user-writable + * overwrite : over-write its own tail + * !overwrite: buffer possibly drops events. + */ + if (rb->overwrite) return true; - mask = perf_data_size(rb) - 1; + /* + * verify that payload is not bigger than buffer + * otherwise masking logic may fail to detect + * the "not enough space" condition + */ + if ((head - offset) > sz) + return false; offset = (offset - tail) & mask; head = (head - tail) & mask; @@ -212,7 +224,9 @@ ring_buffer_init(struct ring_buffer *rb, long watermark, int flags) rb->watermark = max_size / 2; if (flags & RING_BUFFER_WRITABLE) - rb->writable = 1; + rb->overwrite = 0; + else + rb->overwrite = 1; atomic_set(&rb->refcount, 1); @@ -312,11 +326,16 @@ void rb_free(struct ring_buffer *rb) } #else +static int data_page_nr(struct ring_buffer *rb) +{ + return rb->nr_pages << page_order(rb); +} struct page * perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff) { - if (pgoff > (1UL << page_order(rb))) + /* The '>' counts in the user page. */ + if (pgoff > data_page_nr(rb)) return NULL; return vmalloc_to_page((void *)rb->user_page + pgoff * PAGE_SIZE); @@ -336,10 +355,11 @@ static void rb_free_work(struct work_struct *work) int i, nr; rb = container_of(work, struct ring_buffer, work); - nr = 1 << page_order(rb); + nr = data_page_nr(rb); base = rb->user_page; - for (i = 0; i < nr + 1; i++) + /* The '<=' counts in the user page. */ + for (i = 0; i <= nr; i++) perf_mmap_unmark_page(base + (i * PAGE_SIZE)); vfree(base); @@ -373,7 +393,7 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags) rb->user_page = all_buf; rb->data_pages[0] = all_buf + PAGE_SIZE; rb->page_order = ilog2(nr_pages); - rb->nr_pages = 1; + rb->nr_pages = !!nr_pages; ring_buffer_init(rb, watermark, flags); diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index dea7acfbb071..f3569747d629 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -27,6 +27,7 @@ #include <linux/pagemap.h> /* read_mapping_page */ #include <linux/slab.h> #include <linux/sched.h> +#include <linux/export.h> #include <linux/rmap.h> /* anon_vma_prepare */ #include <linux/mmu_notifier.h> /* set_pte_at_notify */ #include <linux/swap.h> /* try_to_free_swap */ @@ -41,58 +42,31 @@ #define MAX_UPROBE_XOL_SLOTS UINSNS_PER_PAGE static struct rb_root uprobes_tree = RB_ROOT; - -static DEFINE_SPINLOCK(uprobes_treelock); /* serialize rbtree access */ - -#define UPROBES_HASH_SZ 13 - /* - * We need separate register/unregister and mmap/munmap lock hashes because - * of mmap_sem nesting. - * - * uprobe_register() needs to install probes on (potentially) all processes - * and thus needs to acquire multiple mmap_sems (consequtively, not - * concurrently), whereas uprobe_mmap() is called while holding mmap_sem - * for the particular process doing the mmap. - * - * uprobe_register()->register_for_each_vma() needs to drop/acquire mmap_sem - * because of lock order against i_mmap_mutex. This means there's a hole in - * the register vma iteration where a mmap() can happen. - * - * Thus uprobe_register() can race with uprobe_mmap() and we can try and - * install a probe where one is already installed. + * allows us to skip the uprobe_mmap if there are no uprobe events active + * at this time. Probably a fine grained per inode count is better? */ +#define no_uprobe_events() RB_EMPTY_ROOT(&uprobes_tree) -/* serialize (un)register */ -static struct mutex uprobes_mutex[UPROBES_HASH_SZ]; - -#define uprobes_hash(v) (&uprobes_mutex[((unsigned long)(v)) % UPROBES_HASH_SZ]) +static DEFINE_SPINLOCK(uprobes_treelock); /* serialize rbtree access */ +#define UPROBES_HASH_SZ 13 /* serialize uprobe->pending_list */ static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ]; #define uprobes_mmap_hash(v) (&uprobes_mmap_mutex[((unsigned long)(v)) % UPROBES_HASH_SZ]) static struct percpu_rw_semaphore dup_mmap_sem; -/* - * uprobe_events allows us to skip the uprobe_mmap if there are no uprobe - * events active at this time. Probably a fine grained per inode count is - * better? - */ -static atomic_t uprobe_events = ATOMIC_INIT(0); - /* Have a copy of original instruction */ #define UPROBE_COPY_INSN 0 -/* Dont run handlers when first register/ last unregister in progress*/ -#define UPROBE_RUN_HANDLER 1 /* Can skip singlestep */ -#define UPROBE_SKIP_SSTEP 2 +#define UPROBE_SKIP_SSTEP 1 struct uprobe { struct rb_node rb_node; /* node in the rb tree */ atomic_t ref; + struct rw_semaphore register_rwsem; struct rw_semaphore consumer_rwsem; - struct mutex copy_mutex; /* TODO: kill me and UPROBE_COPY_INSN */ struct list_head pending_list; struct uprobe_consumer *consumers; struct inode *inode; /* Also hold a ref to inode */ @@ -101,6 +75,15 @@ struct uprobe { struct arch_uprobe arch; }; +struct return_instance { + struct uprobe *uprobe; + unsigned long func; + unsigned long orig_ret_vaddr; /* original return address */ + bool chained; /* true, if instance is nested */ + + struct return_instance *next; /* keep as stack */ +}; + /* * valid_vma: Verify if the specified vma is an executable vma * Relax restrictions while unregistering: vm_flags might have @@ -199,10 +182,31 @@ bool __weak is_swbp_insn(uprobe_opcode_t *insn) return *insn == UPROBE_SWBP_INSN; } -static void copy_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *opcode) +/** + * is_trap_insn - check if instruction is breakpoint instruction. + * @insn: instruction to be checked. + * Default implementation of is_trap_insn + * Returns true if @insn is a breakpoint instruction. + * + * This function is needed for the case where an architecture has multiple + * trap instructions (like powerpc). + */ +bool __weak is_trap_insn(uprobe_opcode_t *insn) +{ + return is_swbp_insn(insn); +} + +static void copy_from_page(struct page *page, unsigned long vaddr, void *dst, int len) { void *kaddr = kmap_atomic(page); - memcpy(opcode, kaddr + (vaddr & ~PAGE_MASK), UPROBE_SWBP_INSN_SIZE); + memcpy(dst, kaddr + (vaddr & ~PAGE_MASK), len); + kunmap_atomic(kaddr); +} + +static void copy_to_page(struct page *page, unsigned long vaddr, const void *src, int len) +{ + void *kaddr = kmap_atomic(page); + memcpy(kaddr + (vaddr & ~PAGE_MASK), src, len); kunmap_atomic(kaddr); } @@ -211,7 +215,16 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t uprobe_opcode_t old_opcode; bool is_swbp; - copy_opcode(page, vaddr, &old_opcode); + /* + * Note: We only check if the old_opcode is UPROBE_SWBP_INSN here. + * We do not check if it is any other 'trap variant' which could + * be conditional trap instruction such as the one powerpc supports. + * + * The logic is that we do not care if the underlying instruction + * is a trap variant; uprobes always wins over any other (gdb) + * breakpoint. + */ + copy_from_page(page, vaddr, &old_opcode, UPROBE_SWBP_INSN_SIZE); is_swbp = is_swbp_insn(&old_opcode); if (is_swbp_insn(new_opcode)) { @@ -230,7 +243,7 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t * Expect the breakpoint instruction to be the smallest size instruction for * the architecture. If an arch has variable length instruction and the * breakpoint instruction is not of the smallest length instruction - * supported by that architecture then we need to modify is_swbp_at_addr and + * supported by that architecture then we need to modify is_trap_at_addr and * write_opcode accordingly. This would never be a problem for archs that * have fixed length instructions. */ @@ -251,7 +264,6 @@ static int write_opcode(struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t opcode) { struct page *old_page, *new_page; - void *vaddr_old, *vaddr_new; struct vm_area_struct *vma; int ret; @@ -272,15 +284,8 @@ retry: __SetPageUptodate(new_page); - /* copy the page now that we've got it stable */ - vaddr_old = kmap_atomic(old_page); - vaddr_new = kmap_atomic(new_page); - - memcpy(vaddr_new, vaddr_old, PAGE_SIZE); - memcpy(vaddr_new + (vaddr & ~PAGE_MASK), &opcode, UPROBE_SWBP_INSN_SIZE); - - kunmap_atomic(vaddr_new); - kunmap_atomic(vaddr_old); + copy_highpage(new_page, old_page); + copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE); ret = anon_vma_prepare(vma); if (ret) @@ -430,9 +435,6 @@ static struct uprobe *insert_uprobe(struct uprobe *uprobe) u = __insert_uprobe(uprobe); spin_unlock(&uprobes_treelock); - /* For now assume that the instruction need not be single-stepped */ - __set_bit(UPROBE_SKIP_SSTEP, &uprobe->flags); - return u; } @@ -452,8 +454,10 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset) uprobe->inode = igrab(inode); uprobe->offset = offset; + init_rwsem(&uprobe->register_rwsem); init_rwsem(&uprobe->consumer_rwsem); - mutex_init(&uprobe->copy_mutex); + /* For now assume that the instruction need not be single-stepped */ + __set_bit(UPROBE_SKIP_SSTEP, &uprobe->flags); /* add to uprobes_tree, sorted on inode:offset */ cur_uprobe = insert_uprobe(uprobe); @@ -463,38 +467,17 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset) kfree(uprobe); uprobe = cur_uprobe; iput(inode); - } else { - atomic_inc(&uprobe_events); } return uprobe; } -static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs) -{ - struct uprobe_consumer *uc; - - if (!test_bit(UPROBE_RUN_HANDLER, &uprobe->flags)) - return; - - down_read(&uprobe->consumer_rwsem); - for (uc = uprobe->consumers; uc; uc = uc->next) { - if (!uc->filter || uc->filter(uc, current)) - uc->handler(uc, regs); - } - up_read(&uprobe->consumer_rwsem); -} - -/* Returns the previous consumer */ -static struct uprobe_consumer * -consumer_add(struct uprobe *uprobe, struct uprobe_consumer *uc) +static void consumer_add(struct uprobe *uprobe, struct uprobe_consumer *uc) { down_write(&uprobe->consumer_rwsem); uc->next = uprobe->consumers; uprobe->consumers = uc; up_write(&uprobe->consumer_rwsem); - - return uc->next; } /* @@ -525,30 +508,18 @@ __copy_insn(struct address_space *mapping, struct file *filp, char *insn, unsigned long nbytes, loff_t offset) { struct page *page; - void *vaddr; - unsigned long off; - pgoff_t idx; - - if (!filp) - return -EINVAL; if (!mapping->a_ops->readpage) return -EIO; - - idx = offset >> PAGE_CACHE_SHIFT; - off = offset & ~PAGE_MASK; - /* * Ensure that the page that has the original instruction is * populated and in page-cache. */ - page = read_mapping_page(mapping, idx, filp); + page = read_mapping_page(mapping, offset >> PAGE_CACHE_SHIFT, filp); if (IS_ERR(page)) return PTR_ERR(page); - vaddr = kmap_atomic(page); - memcpy(insn, vaddr + off, nbytes); - kunmap_atomic(vaddr); + copy_from_page(page, offset, insn, nbytes); page_cache_release(page); return 0; @@ -588,7 +559,8 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, if (test_bit(UPROBE_COPY_INSN, &uprobe->flags)) return ret; - mutex_lock(&uprobe->copy_mutex); + /* TODO: move this into _register, until then we abuse this sem. */ + down_write(&uprobe->consumer_rwsem); if (test_bit(UPROBE_COPY_INSN, &uprobe->flags)) goto out; @@ -597,7 +569,7 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, goto out; ret = -ENOTSUPP; - if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn)) + if (is_trap_insn((uprobe_opcode_t *)uprobe->arch.insn)) goto out; ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, vaddr); @@ -612,7 +584,30 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, set_bit(UPROBE_COPY_INSN, &uprobe->flags); out: - mutex_unlock(&uprobe->copy_mutex); + up_write(&uprobe->consumer_rwsem); + + return ret; +} + +static inline bool consumer_filter(struct uprobe_consumer *uc, + enum uprobe_filter_ctx ctx, struct mm_struct *mm) +{ + return !uc->filter || uc->filter(uc, ctx, mm); +} + +static bool filter_chain(struct uprobe *uprobe, + enum uprobe_filter_ctx ctx, struct mm_struct *mm) +{ + struct uprobe_consumer *uc; + bool ret = false; + + down_read(&uprobe->consumer_rwsem); + for (uc = uprobe->consumers; uc; uc = uc->next) { + ret = consumer_filter(uc, ctx, mm); + if (ret) + break; + } + up_read(&uprobe->consumer_rwsem); return ret; } @@ -624,16 +619,6 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, bool first_uprobe; int ret; - /* - * If probe is being deleted, unregister thread could be done with - * the vma-rmap-walk through. Adding a probe now can be fatal since - * nobody will be able to cleanup. Also we could be from fork or - * mremap path, where the probe might have already been inserted. - * Hence behave as if probe already existed. - */ - if (!uprobe->consumers) - return 0; - ret = prepare_uprobe(uprobe, vma->vm_file, mm, vaddr); if (ret) return ret; @@ -658,14 +643,14 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, static int remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr) { - /* can happen if uprobe_register() fails */ - if (!test_bit(MMF_HAS_UPROBES, &mm->flags)) - return 0; - set_bit(MMF_RECALC_UPROBES, &mm->flags); return set_orig_insn(&uprobe->arch, mm, vaddr); } +static inline bool uprobe_is_active(struct uprobe *uprobe) +{ + return !RB_EMPTY_NODE(&uprobe->rb_node); +} /* * There could be threads that have already hit the breakpoint. They * will recheck the current insn and restart if find_uprobe() fails. @@ -673,12 +658,15 @@ remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vad */ static void delete_uprobe(struct uprobe *uprobe) { + if (WARN_ON(!uprobe_is_active(uprobe))) + return; + spin_lock(&uprobes_treelock); rb_erase(&uprobe->rb_node, &uprobes_tree); spin_unlock(&uprobes_treelock); + RB_CLEAR_NODE(&uprobe->rb_node); /* for uprobe_is_active() */ iput(uprobe->inode); put_uprobe(uprobe); - atomic_dec(&uprobe_events); } struct map_info { @@ -764,8 +752,10 @@ build_map_info(struct address_space *mapping, loff_t offset, bool is_register) return curr; } -static int register_for_each_vma(struct uprobe *uprobe, bool is_register) +static int +register_for_each_vma(struct uprobe *uprobe, struct uprobe_consumer *new) { + bool is_register = !!new; struct map_info *info; int err = 0; @@ -787,17 +777,23 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) down_write(&mm->mmap_sem); vma = find_vma(mm, info->vaddr); if (!vma || !valid_vma(vma, is_register) || - vma->vm_file->f_mapping->host != uprobe->inode) + file_inode(vma->vm_file) != uprobe->inode) goto unlock; if (vma->vm_start > info->vaddr || vaddr_to_offset(vma, info->vaddr) != uprobe->offset) goto unlock; - if (is_register) - err = install_breakpoint(uprobe, mm, vma, info->vaddr); - else - err |= remove_breakpoint(uprobe, mm, info->vaddr); + if (is_register) { + /* consult only the "caller", new consumer. */ + if (consumer_filter(new, + UPROBE_FILTER_REGISTER, mm)) + err = install_breakpoint(uprobe, mm, vma, info->vaddr); + } else if (test_bit(MMF_HAS_UPROBES, &mm->flags)) { + if (!filter_chain(uprobe, + UPROBE_FILTER_UNREGISTER, mm)) + err |= remove_breakpoint(uprobe, mm, info->vaddr); + } unlock: up_write(&mm->mmap_sem); @@ -810,17 +806,23 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) return err; } -static int __uprobe_register(struct uprobe *uprobe) +static int __uprobe_register(struct uprobe *uprobe, struct uprobe_consumer *uc) { - return register_for_each_vma(uprobe, true); + consumer_add(uprobe, uc); + return register_for_each_vma(uprobe, uc); } -static void __uprobe_unregister(struct uprobe *uprobe) +static void __uprobe_unregister(struct uprobe *uprobe, struct uprobe_consumer *uc) { - if (!register_for_each_vma(uprobe, false)) - delete_uprobe(uprobe); + int err; + if (!consumer_del(uprobe, uc)) /* WARN? */ + return; + + err = register_for_each_vma(uprobe, NULL); /* TODO : cant unregister? schedule a worker thread */ + if (!uprobe->consumers && !err) + delete_uprobe(uprobe); } /* @@ -845,31 +847,63 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer * struct uprobe *uprobe; int ret; - if (!inode || !uc || uc->next) + /* Uprobe must have at least one set consumer */ + if (!uc->handler && !uc->ret_handler) return -EINVAL; + /* Racy, just to catch the obvious mistakes */ if (offset > i_size_read(inode)) return -EINVAL; - ret = 0; - mutex_lock(uprobes_hash(inode)); + retry: uprobe = alloc_uprobe(inode, offset); - - if (!uprobe) { - ret = -ENOMEM; - } else if (!consumer_add(uprobe, uc)) { - ret = __uprobe_register(uprobe); - if (ret) { - uprobe->consumers = NULL; - __uprobe_unregister(uprobe); - } else { - set_bit(UPROBE_RUN_HANDLER, &uprobe->flags); - } + if (!uprobe) + return -ENOMEM; + /* + * We can race with uprobe_unregister()->delete_uprobe(). + * Check uprobe_is_active() and retry if it is false. + */ + down_write(&uprobe->register_rwsem); + ret = -EAGAIN; + if (likely(uprobe_is_active(uprobe))) { + ret = __uprobe_register(uprobe, uc); + if (ret) + __uprobe_unregister(uprobe, uc); } + up_write(&uprobe->register_rwsem); + put_uprobe(uprobe); - mutex_unlock(uprobes_hash(inode)); - if (uprobe) - put_uprobe(uprobe); + if (unlikely(ret == -EAGAIN)) + goto retry; + return ret; +} +EXPORT_SYMBOL_GPL(uprobe_register); + +/* + * uprobe_apply - unregister a already registered probe. + * @inode: the file in which the probe has to be removed. + * @offset: offset from the start of the file. + * @uc: consumer which wants to add more or remove some breakpoints + * @add: add or remove the breakpoints + */ +int uprobe_apply(struct inode *inode, loff_t offset, + struct uprobe_consumer *uc, bool add) +{ + struct uprobe *uprobe; + struct uprobe_consumer *con; + int ret = -ENOENT; + + uprobe = find_uprobe(inode, offset); + if (!uprobe) + return ret; + + down_write(&uprobe->register_rwsem); + for (con = uprobe->consumers; con && con != uc ; con = con->next) + ; + if (con) + ret = register_for_each_vma(uprobe, add ? uc : NULL); + up_write(&uprobe->register_rwsem); + put_uprobe(uprobe); return ret; } @@ -884,25 +918,42 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume { struct uprobe *uprobe; - if (!inode || !uc) - return; - uprobe = find_uprobe(inode, offset); if (!uprobe) return; - mutex_lock(uprobes_hash(inode)); + down_write(&uprobe->register_rwsem); + __uprobe_unregister(uprobe, uc); + up_write(&uprobe->register_rwsem); + put_uprobe(uprobe); +} +EXPORT_SYMBOL_GPL(uprobe_unregister); - if (consumer_del(uprobe, uc)) { - if (!uprobe->consumers) { - __uprobe_unregister(uprobe); - clear_bit(UPROBE_RUN_HANDLER, &uprobe->flags); - } +static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm) +{ + struct vm_area_struct *vma; + int err = 0; + + down_read(&mm->mmap_sem); + for (vma = mm->mmap; vma; vma = vma->vm_next) { + unsigned long vaddr; + loff_t offset; + + if (!valid_vma(vma, false) || + file_inode(vma->vm_file) != uprobe->inode) + continue; + + offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; + if (uprobe->offset < offset || + uprobe->offset >= offset + vma->vm_end - vma->vm_start) + continue; + + vaddr = offset_to_vaddr(vma, uprobe->offset); + err |= remove_breakpoint(uprobe, mm, vaddr); } + up_read(&mm->mmap_sem); - mutex_unlock(uprobes_hash(inode)); - if (uprobe) - put_uprobe(uprobe); + return err; } static struct rb_node * @@ -979,18 +1030,23 @@ int uprobe_mmap(struct vm_area_struct *vma) struct uprobe *uprobe, *u; struct inode *inode; - if (!atomic_read(&uprobe_events) || !valid_vma(vma, true)) + if (no_uprobe_events() || !valid_vma(vma, true)) return 0; - inode = vma->vm_file->f_mapping->host; + inode = file_inode(vma->vm_file); if (!inode) return 0; mutex_lock(uprobes_mmap_hash(inode)); build_probe_list(inode, vma, vma->vm_start, vma->vm_end, &tmp_list); - + /* + * We can race with uprobe_unregister(), this uprobe can be already + * removed. But in this case filter_chain() must return false, all + * consumers have gone away. + */ list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) { - if (!fatal_signal_pending(current)) { + if (!fatal_signal_pending(current) && + filter_chain(uprobe, UPROBE_FILTER_MMAP, vma->vm_mm)) { unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset); install_breakpoint(uprobe, vma->vm_mm, vma, vaddr); } @@ -1008,7 +1064,7 @@ vma_has_uprobes(struct vm_area_struct *vma, unsigned long start, unsigned long e struct inode *inode; struct rb_node *n; - inode = vma->vm_file->f_mapping->host; + inode = file_inode(vma->vm_file); min = vaddr_to_offset(vma, start); max = min + (end - start) - 1; @@ -1025,7 +1081,7 @@ vma_has_uprobes(struct vm_area_struct *vma, unsigned long start, unsigned long e */ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end) { - if (!atomic_read(&uprobe_events) || !valid_vma(vma, false)) + if (no_uprobe_events() || !valid_vma(vma, false)) return; if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */ @@ -1042,22 +1098,14 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon /* Slot allocation for XOL */ static int xol_add_vma(struct xol_area *area) { - struct mm_struct *mm; - int ret; - - area->page = alloc_page(GFP_HIGHUSER); - if (!area->page) - return -ENOMEM; - - ret = -EALREADY; - mm = current->mm; + struct mm_struct *mm = current->mm; + int ret = -EALREADY; down_write(&mm->mmap_sem); if (mm->uprobes_state.xol_area) goto fail; ret = -ENOMEM; - /* Try to map as high as possible, this is only a hint. */ area->vaddr = get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE, PAGE_SIZE, 0, 0); if (area->vaddr & ~PAGE_MASK) { @@ -1073,54 +1121,59 @@ static int xol_add_vma(struct xol_area *area) smp_wmb(); /* pairs with get_xol_area() */ mm->uprobes_state.xol_area = area; ret = 0; - -fail: + fail: up_write(&mm->mmap_sem); - if (ret) - __free_page(area->page); return ret; } -static struct xol_area *get_xol_area(struct mm_struct *mm) -{ - struct xol_area *area; - - area = mm->uprobes_state.xol_area; - smp_read_barrier_depends(); /* pairs with wmb in xol_add_vma() */ - - return area; -} - /* - * xol_alloc_area - Allocate process's xol_area. - * This area will be used for storing instructions for execution out of - * line. + * get_xol_area - Allocate process's xol_area if necessary. + * This area will be used for storing instructions for execution out of line. * * Returns the allocated area or NULL. */ -static struct xol_area *xol_alloc_area(void) +static struct xol_area *get_xol_area(void) { + struct mm_struct *mm = current->mm; struct xol_area *area; + uprobe_opcode_t insn = UPROBE_SWBP_INSN; + + area = mm->uprobes_state.xol_area; + if (area) + goto ret; area = kzalloc(sizeof(*area), GFP_KERNEL); if (unlikely(!area)) - return NULL; + goto out; area->bitmap = kzalloc(BITS_TO_LONGS(UINSNS_PER_PAGE) * sizeof(long), GFP_KERNEL); - if (!area->bitmap) - goto fail; + goto free_area; + + area->page = alloc_page(GFP_HIGHUSER); + if (!area->page) + goto free_bitmap; + /* allocate first slot of task's xol_area for the return probes */ + set_bit(0, area->bitmap); + copy_to_page(area->page, 0, &insn, UPROBE_SWBP_INSN_SIZE); + atomic_set(&area->slot_count, 1); init_waitqueue_head(&area->wq); + if (!xol_add_vma(area)) return area; -fail: + __free_page(area->page); + free_bitmap: kfree(area->bitmap); + free_area: kfree(area); - - return get_xol_area(current->mm); + out: + area = mm->uprobes_state.xol_area; + ret: + smp_read_barrier_depends(); /* pairs with wmb in xol_add_vma() */ + return area; } /* @@ -1186,43 +1239,31 @@ static unsigned long xol_take_insn_slot(struct xol_area *area) } /* - * xol_get_insn_slot - If was not allocated a slot, then - * allocate a slot. + * xol_get_insn_slot - allocate a slot for xol. * Returns the allocated slot address or 0. */ -static unsigned long xol_get_insn_slot(struct uprobe *uprobe, unsigned long slot_addr) +static unsigned long xol_get_insn_slot(struct uprobe *uprobe) { struct xol_area *area; - unsigned long offset; - void *vaddr; + unsigned long xol_vaddr; - area = get_xol_area(current->mm); - if (!area) { - area = xol_alloc_area(); - if (!area) - return 0; - } - current->utask->xol_vaddr = xol_take_insn_slot(area); + area = get_xol_area(); + if (!area) + return 0; - /* - * Initialize the slot if xol_vaddr points to valid - * instruction slot. - */ - if (unlikely(!current->utask->xol_vaddr)) + xol_vaddr = xol_take_insn_slot(area); + if (unlikely(!xol_vaddr)) return 0; - current->utask->vaddr = slot_addr; - offset = current->utask->xol_vaddr & ~PAGE_MASK; - vaddr = kmap_atomic(area->page); - memcpy(vaddr + offset, uprobe->arch.insn, MAX_UINSN_BYTES); - kunmap_atomic(vaddr); + /* Initialize the slot */ + copy_to_page(area->page, xol_vaddr, uprobe->arch.insn, MAX_UINSN_BYTES); /* * We probably need flush_icache_user_range() but it needs vma. * This should work on supported architectures too. */ flush_dcache_page(area->page); - return current->utask->xol_vaddr; + return xol_vaddr; } /* @@ -1240,8 +1281,7 @@ static void xol_free_insn_slot(struct task_struct *tsk) return; slot_addr = tsk->utask->xol_vaddr; - - if (unlikely(!slot_addr || IS_ERR_VALUE(slot_addr))) + if (unlikely(!slot_addr)) return; area = tsk->mm->uprobes_state.xol_area; @@ -1282,6 +1322,7 @@ unsigned long __weak uprobe_get_swbp_addr(struct pt_regs *regs) void uprobe_free_utask(struct task_struct *t) { struct uprobe_task *utask = t->utask; + struct return_instance *ri, *tmp; if (!utask) return; @@ -1289,6 +1330,15 @@ void uprobe_free_utask(struct task_struct *t) if (utask->active_uprobe) put_uprobe(utask->active_uprobe); + ri = utask->return_instances; + while (ri) { + tmp = ri; + ri = ri->next; + + put_uprobe(tmp->uprobe); + kfree(tmp); + } + xol_free_insn_slot(t); kfree(utask); t->utask = NULL; @@ -1303,33 +1353,135 @@ void uprobe_copy_process(struct task_struct *t) } /* - * Allocate a uprobe_task object for the task. - * Called when the thread hits a breakpoint for the first time. + * Allocate a uprobe_task object for the task if if necessary. + * Called when the thread hits a breakpoint. * * Returns: * - pointer to new uprobe_task on success * - NULL otherwise */ -static struct uprobe_task *add_utask(void) +static struct uprobe_task *get_utask(void) { + if (!current->utask) + current->utask = kzalloc(sizeof(struct uprobe_task), GFP_KERNEL); + return current->utask; +} + +/* + * Current area->vaddr notion assume the trampoline address is always + * equal area->vaddr. + * + * Returns -1 in case the xol_area is not allocated. + */ +static unsigned long get_trampoline_vaddr(void) +{ + struct xol_area *area; + unsigned long trampoline_vaddr = -1; + + area = current->mm->uprobes_state.xol_area; + smp_read_barrier_depends(); + if (area) + trampoline_vaddr = area->vaddr; + + return trampoline_vaddr; +} + +static void prepare_uretprobe(struct uprobe *uprobe, struct pt_regs *regs) +{ + struct return_instance *ri; struct uprobe_task *utask; + unsigned long orig_ret_vaddr, trampoline_vaddr; + bool chained = false; - utask = kzalloc(sizeof *utask, GFP_KERNEL); - if (unlikely(!utask)) - return NULL; + if (!get_xol_area()) + return; + + utask = get_utask(); + if (!utask) + return; - current->utask = utask; - return utask; + if (utask->depth >= MAX_URETPROBE_DEPTH) { + printk_ratelimited(KERN_INFO "uprobe: omit uretprobe due to" + " nestedness limit pid/tgid=%d/%d\n", + current->pid, current->tgid); + return; + } + + ri = kzalloc(sizeof(struct return_instance), GFP_KERNEL); + if (!ri) + goto fail; + + trampoline_vaddr = get_trampoline_vaddr(); + orig_ret_vaddr = arch_uretprobe_hijack_return_addr(trampoline_vaddr, regs); + if (orig_ret_vaddr == -1) + goto fail; + + /* + * We don't want to keep trampoline address in stack, rather keep the + * original return address of first caller thru all the consequent + * instances. This also makes breakpoint unwrapping easier. + */ + if (orig_ret_vaddr == trampoline_vaddr) { + if (!utask->return_instances) { + /* + * This situation is not possible. Likely we have an + * attack from user-space. + */ + pr_warn("uprobe: unable to set uretprobe pid/tgid=%d/%d\n", + current->pid, current->tgid); + goto fail; + } + + chained = true; + orig_ret_vaddr = utask->return_instances->orig_ret_vaddr; + } + + atomic_inc(&uprobe->ref); + ri->uprobe = uprobe; + ri->func = instruction_pointer(regs); + ri->orig_ret_vaddr = orig_ret_vaddr; + ri->chained = chained; + + utask->depth++; + + /* add instance to the stack */ + ri->next = utask->return_instances; + utask->return_instances = ri; + + return; + + fail: + kfree(ri); } /* Prepare to single-step probed instruction out of line. */ static int -pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long vaddr) +pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long bp_vaddr) { - if (xol_get_insn_slot(uprobe, vaddr) && !arch_uprobe_pre_xol(&uprobe->arch, regs)) - return 0; + struct uprobe_task *utask; + unsigned long xol_vaddr; + int err; - return -EFAULT; + utask = get_utask(); + if (!utask) + return -ENOMEM; + + xol_vaddr = xol_get_insn_slot(uprobe); + if (!xol_vaddr) + return -ENOMEM; + + utask->xol_vaddr = xol_vaddr; + utask->vaddr = bp_vaddr; + + err = arch_uprobe_pre_xol(&uprobe->arch, regs); + if (unlikely(err)) { + xol_free_insn_slot(current); + return err; + } + + utask->active_uprobe = uprobe; + utask->state = UTASK_SSTEP; + return 0; } /* @@ -1391,6 +1543,7 @@ static void mmf_recalc_uprobes(struct mm_struct *mm) * This is not strictly accurate, we can race with * uprobe_unregister() and see the already removed * uprobe if delete_uprobe() was not yet called. + * Or this uprobe can be filtered out. */ if (vma_has_uprobes(vma, vma->vm_start, vma->vm_end)) return; @@ -1399,7 +1552,7 @@ static void mmf_recalc_uprobes(struct mm_struct *mm) clear_bit(MMF_HAS_UPROBES, &mm->flags); } -static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr) +static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr) { struct page *page; uprobe_opcode_t opcode; @@ -1417,10 +1570,11 @@ static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr) if (result < 0) return result; - copy_opcode(page, vaddr, &opcode); + copy_from_page(page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE); put_page(page); out: - return is_swbp_insn(&opcode); + /* This needs to return true for any variant of the trap insn */ + return is_trap_insn(&opcode); } static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp) @@ -1433,14 +1587,14 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp) vma = find_vma(mm, bp_vaddr); if (vma && vma->vm_start <= bp_vaddr) { if (valid_vma(vma, false)) { - struct inode *inode = vma->vm_file->f_mapping->host; + struct inode *inode = file_inode(vma->vm_file); loff_t offset = vaddr_to_offset(vma, bp_vaddr); uprobe = find_uprobe(inode, offset); } if (!uprobe) - *is_swbp = is_swbp_at_addr(mm, bp_vaddr); + *is_swbp = is_trap_at_addr(mm, bp_vaddr); } else { *is_swbp = -EFAULT; } @@ -1452,20 +1606,116 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp) return uprobe; } +static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs) +{ + struct uprobe_consumer *uc; + int remove = UPROBE_HANDLER_REMOVE; + bool need_prep = false; /* prepare return uprobe, when needed */ + + down_read(&uprobe->register_rwsem); + for (uc = uprobe->consumers; uc; uc = uc->next) { + int rc = 0; + + if (uc->handler) { + rc = uc->handler(uc, regs); + WARN(rc & ~UPROBE_HANDLER_MASK, + "bad rc=0x%x from %pf()\n", rc, uc->handler); + } + + if (uc->ret_handler) + need_prep = true; + + remove &= rc; + } + + if (need_prep && !remove) + prepare_uretprobe(uprobe, regs); /* put bp at return */ + + if (remove && uprobe->consumers) { + WARN_ON(!uprobe_is_active(uprobe)); + unapply_uprobe(uprobe, current->mm); + } + up_read(&uprobe->register_rwsem); +} + +static void +handle_uretprobe_chain(struct return_instance *ri, struct pt_regs *regs) +{ + struct uprobe *uprobe = ri->uprobe; + struct uprobe_consumer *uc; + + down_read(&uprobe->register_rwsem); + for (uc = uprobe->consumers; uc; uc = uc->next) { + if (uc->ret_handler) + uc->ret_handler(uc, ri->func, regs); + } + up_read(&uprobe->register_rwsem); +} + +static bool handle_trampoline(struct pt_regs *regs) +{ + struct uprobe_task *utask; + struct return_instance *ri, *tmp; + bool chained; + + utask = current->utask; + if (!utask) + return false; + + ri = utask->return_instances; + if (!ri) + return false; + + /* + * TODO: we should throw out return_instance's invalidated by + * longjmp(), currently we assume that the probed function always + * returns. + */ + instruction_pointer_set(regs, ri->orig_ret_vaddr); + + for (;;) { + handle_uretprobe_chain(ri, regs); + + chained = ri->chained; + put_uprobe(ri->uprobe); + + tmp = ri; + ri = ri->next; + kfree(tmp); + + if (!chained) + break; + + utask->depth--; + + BUG_ON(!ri); + } + + utask->return_instances = ri; + + return true; +} + /* * Run handler and ask thread to singlestep. * Ensure all non-fatal signals cannot interrupt thread while it singlesteps. */ static void handle_swbp(struct pt_regs *regs) { - struct uprobe_task *utask; struct uprobe *uprobe; unsigned long bp_vaddr; int uninitialized_var(is_swbp); bp_vaddr = uprobe_get_swbp_addr(regs); - uprobe = find_active_uprobe(bp_vaddr, &is_swbp); + if (bp_vaddr == get_trampoline_vaddr()) { + if (handle_trampoline(regs)) + return; + + pr_warn("uprobe: unable to handle uretprobe pid/tgid=%d/%d\n", + current->pid, current->tgid); + } + uprobe = find_active_uprobe(bp_vaddr, &is_swbp); if (!uprobe) { if (is_swbp > 0) { /* No matching uprobe; signal SIGTRAP. */ @@ -1483,6 +1733,10 @@ static void handle_swbp(struct pt_regs *regs) } return; } + + /* change it in advance for ->handler() and restart */ + instruction_pointer_set(regs, bp_vaddr); + /* * TODO: move copy_insn/etc into _register and remove this hack. * After we hit the bp, _unregister + _register can install the @@ -1490,32 +1744,16 @@ static void handle_swbp(struct pt_regs *regs) */ smp_rmb(); /* pairs with wmb() in install_breakpoint() */ if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags))) - goto restart; - - utask = current->utask; - if (!utask) { - utask = add_utask(); - /* Cannot allocate; re-execute the instruction. */ - if (!utask) - goto restart; - } + goto out; handler_chain(uprobe, regs); if (can_skip_sstep(uprobe, regs)) goto out; - if (!pre_ssout(uprobe, regs, bp_vaddr)) { - utask->active_uprobe = uprobe; - utask->state = UTASK_SSTEP; + if (!pre_ssout(uprobe, regs, bp_vaddr)) return; - } -restart: - /* - * cannot singlestep; cannot skip instruction; - * re-execute the instruction. - */ - instruction_pointer_set(regs, bp_vaddr); + /* can_skip_sstep() succeeded, or restart if can't singlestep */ out: put_uprobe(uprobe); } @@ -1576,7 +1814,11 @@ void uprobe_notify_resume(struct pt_regs *regs) */ int uprobe_pre_sstep_notifier(struct pt_regs *regs) { - if (!current->mm || !test_bit(MMF_HAS_UPROBES, ¤t->mm->flags)) + if (!current->mm) + return 0; + + if (!test_bit(MMF_HAS_UPROBES, ¤t->mm->flags) && + (!current->utask || !current->utask->return_instances)) return 0; set_thread_flag(TIF_UPROBE); @@ -1609,10 +1851,8 @@ static int __init init_uprobes(void) { int i; - for (i = 0; i < UPROBES_HASH_SZ; i++) { - mutex_init(&uprobes_mutex[i]); + for (i = 0; i < UPROBES_HASH_SZ; i++) mutex_init(&uprobes_mmap_mutex[i]); - } if (percpu_init_rwsem(&dup_mmap_sem)) return -ENOMEM; diff --git a/kernel/exit.c b/kernel/exit.c index b4df21937216..af2eb3cbd499 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -20,6 +20,7 @@ #include <linux/tsacct_kern.h> #include <linux/file.h> #include <linux/fdtable.h> +#include <linux/freezer.h> #include <linux/binfmts.h> #include <linux/nsproxy.h> #include <linux/pid_namespace.h> @@ -31,7 +32,6 @@ #include <linux/mempolicy.h> #include <linux/taskstats_kern.h> #include <linux/delayacct.h> -#include <linux/freezer.h> #include <linux/cgroup.h> #include <linux/syscalls.h> #include <linux/signal.h> @@ -85,6 +85,7 @@ static void __exit_signal(struct task_struct *tsk) bool group_dead = thread_group_leader(tsk); struct sighand_struct *sighand; struct tty_struct *uninitialized_var(tty); + cputime_t utime, stime; sighand = rcu_dereference_check(tsk->sighand, lockdep_tasklist_lock_is_held()); @@ -123,9 +124,10 @@ static void __exit_signal(struct task_struct *tsk) * We won't ever get here for the group leader, since it * will have been the last reference on the signal_struct. */ - sig->utime += tsk->utime; - sig->stime += tsk->stime; - sig->gtime += tsk->gtime; + task_cputime(tsk, &utime, &stime); + sig->utime += utime; + sig->stime += stime; + sig->gtime += task_gtime(tsk); sig->min_flt += tsk->min_flt; sig->maj_flt += tsk->maj_flt; sig->nvcsw += tsk->nvcsw; @@ -483,7 +485,7 @@ static void exit_mm(struct task_struct * tsk) set_task_state(tsk, TASK_UNINTERRUPTIBLE); if (!self.task) /* see coredump_finish() */ break; - schedule(); + freezable_schedule(); } __set_task_state(tsk, TASK_RUNNING); down_read(&mm->mmap_sem); @@ -845,7 +847,7 @@ void do_exit(long code) exit_io_context(tsk); if (tsk->splice_pipe) - __free_pipe_info(tsk->splice_pipe); + free_pipe_info(tsk->splice_pipe); if (tsk->task_frag.page) put_page(tsk->task_frag.page); @@ -1092,7 +1094,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) sig = p->signal; psig->cutime += tgutime + sig->cutime; psig->cstime += tgstime + sig->cstime; - psig->cgtime += p->gtime + sig->gtime + sig->cgtime; + psig->cgtime += task_gtime(p) + sig->gtime + sig->cgtime; psig->cmin_flt += p->min_flt + sig->min_flt + sig->cmin_flt; psig->cmaj_flt += @@ -1627,9 +1629,6 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, } put_pid(pid); - - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(5, ret, which, upid, infop, options, ru); return ret; } @@ -1667,8 +1666,6 @@ SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr, ret = do_wait(&wo); put_pid(pid); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(4, ret, upid, stat_addr, options, ru); return ret; } diff --git a/kernel/extable.c b/kernel/extable.c index fe35a634bf76..67460b93b1a1 100644 --- a/kernel/extable.c +++ b/kernel/extable.c @@ -41,10 +41,10 @@ u32 __initdata main_extable_sort_needed = 1; /* Sort the kernel's built-in exception table */ void __init sort_main_extable(void) { - if (main_extable_sort_needed) + if (main_extable_sort_needed) { + pr_notice("Sorting __ex_table...\n"); sort_extable(__start___ex_table, __stop___ex_table); - else - pr_notice("__ex_table already sorted, skipping sort\n"); + } } /* Given an address, look for it in the exception tables. */ diff --git a/kernel/fork.c b/kernel/fork.c index c535f33bbb9c..987b28a1f01b 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -70,6 +70,7 @@ #include <linux/khugepaged.h> #include <linux/signalfd.h> #include <linux/uprobes.h> +#include <linux/aio.h> #include <asm/pgtable.h> #include <asm/pgalloc.h> @@ -413,7 +414,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) tmp->vm_next = tmp->vm_prev = NULL; file = tmp->vm_file; if (file) { - struct inode *inode = file->f_path.dentry->d_inode; + struct inode *inode = file_inode(file); struct address_space *mapping = file->f_mapping; get_file(file); @@ -1141,6 +1142,9 @@ static struct task_struct *copy_process(unsigned long clone_flags, if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS)) return ERR_PTR(-EINVAL); + if ((clone_flags & (CLONE_NEWUSER|CLONE_FS)) == (CLONE_NEWUSER|CLONE_FS)) + return ERR_PTR(-EINVAL); + /* * Thread groups must share signals as well, and detached threads * can only be started up within the thread group. @@ -1230,9 +1234,15 @@ static struct task_struct *copy_process(unsigned long clone_flags, p->utime = p->stime = p->gtime = 0; p->utimescaled = p->stimescaled = 0; -#ifndef CONFIG_VIRT_CPU_ACCOUNTING +#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE p->prev_cputime.utime = p->prev_cputime.stime = 0; #endif +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN + seqlock_init(&p->vtime_seqlock); + p->vtime_snap = 0; + p->vtime_snap_whence = VTIME_SLEEPING; +#endif + #if defined(SPLIT_RSS_COUNTING) memset(&p->rss_stat, 0, sizeof(p->rss_stat)); #endif @@ -1294,6 +1304,10 @@ static struct task_struct *copy_process(unsigned long clone_flags, p->memcg_batch.do_batch = 0; p->memcg_batch.memcg = NULL; #endif +#ifdef CONFIG_BCACHE + p->sequential_io = 0; + p->sequential_io_avg = 0; +#endif /* Perform scheduler related setup. Assign this task to a CPU. */ sched_fork(p); @@ -1668,10 +1682,7 @@ SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp, int, tls_val) #endif { - long ret = do_fork(clone_flags, newsp, 0, parent_tidptr, child_tidptr); - asmlinkage_protect(5, ret, clone_flags, newsp, - parent_tidptr, child_tidptr, tls_val); - return ret; + return do_fork(clone_flags, newsp, 0, parent_tidptr, child_tidptr); } #endif @@ -1801,7 +1812,7 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags) * If unsharing a user namespace must also unshare the thread. */ if (unshare_flags & CLONE_NEWUSER) - unshare_flags |= CLONE_THREAD; + unshare_flags |= CLONE_THREAD | CLONE_FS; /* * If unsharing a pid namespace must also unshare the thread. */ @@ -1855,10 +1866,8 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags) exit_sem(current); } - if (new_nsproxy) { + if (new_nsproxy) switch_task_namespaces(current, new_nsproxy); - new_nsproxy = NULL; - } task_lock(current); @@ -1888,9 +1897,6 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags) } } - if (new_nsproxy) - put_nsproxy(new_nsproxy); - bad_unshare_cleanup_cred: if (new_cred) put_cred(new_cred); diff --git a/kernel/futex.c b/kernel/futex.c index 19eb089ca003..b26dcfc02c94 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -60,6 +60,7 @@ #include <linux/pid.h> #include <linux/nsproxy.h> #include <linux/ptrace.h> +#include <linux/sched/rt.h> #include <asm/futex.h> @@ -222,10 +223,11 @@ static void drop_futex_key_refs(union futex_key *key) * @rw: mapping needs to be read/write (values: VERIFY_READ, * VERIFY_WRITE) * - * Returns a negative error code or 0 + * Return: a negative error code or 0 + * * The key words are stored in *key on success. * - * For shared mappings, it's (page->index, vma->vm_file->f_path.dentry->d_inode, + * For shared mappings, it's (page->index, file_inode(vma->vm_file), * offset_within_page). For private mappings, it's (uaddr, current->mm). * We can usually work out the index without swapping in the page. * @@ -704,9 +706,9 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb, * be "current" except in the case of requeue pi. * @set_waiters: force setting the FUTEX_WAITERS bit (1) or not (0) * - * Returns: - * 0 - ready to wait - * 1 - acquired the lock + * Return: + * 0 - ready to wait; + * 1 - acquired the lock; * <0 - error * * The hb->lock and futex_key refs shall be held by the caller. @@ -1190,9 +1192,9 @@ void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key, * then direct futex_lock_pi_atomic() to force setting the FUTEX_WAITERS bit. * hb1 and hb2 must be held by the caller. * - * Returns: - * 0 - failed to acquire the lock atomicly - * 1 - acquired the lock + * Return: + * 0 - failed to acquire the lock atomically; + * 1 - acquired the lock; * <0 - error */ static int futex_proxy_trylock_atomic(u32 __user *pifutex, @@ -1253,8 +1255,8 @@ static int futex_proxy_trylock_atomic(u32 __user *pifutex, * Requeue waiters on uaddr1 to uaddr2. In the requeue_pi case, try to acquire * uaddr2 atomically on behalf of the top waiter. * - * Returns: - * >=0 - on success, the number of tasks requeued or woken + * Return: + * >=0 - on success, the number of tasks requeued or woken; * <0 - on error */ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, @@ -1535,8 +1537,8 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb) * The q->lock_ptr must not be held by the caller. A call to unqueue_me() must * be paired with exactly one earlier call to queue_me(). * - * Returns: - * 1 - if the futex_q was still queued (and we removed unqueued it) + * Return: + * 1 - if the futex_q was still queued (and we removed unqueued it); * 0 - if the futex_q was already removed by the waking thread */ static int unqueue_me(struct futex_q *q) @@ -1706,9 +1708,9 @@ static long futex_wait_restart(struct restart_block *restart); * the pi_state owner as well as handle race conditions that may allow us to * acquire the lock. Must be called with the hb lock held. * - * Returns: - * 1 - success, lock taken - * 0 - success, lock not taken + * Return: + * 1 - success, lock taken; + * 0 - success, lock not taken; * <0 - on error (-EFAULT) */ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked) @@ -1823,8 +1825,8 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q, * Return with the hb lock held and a q.key reference on success, and unlocked * with no q.key reference on failure. * - * Returns: - * 0 - uaddr contains val and hb has been locked + * Return: + * 0 - uaddr contains val and hb has been locked; * <1 - -EFAULT or -EWOULDBLOCK (uaddr does not contain val) and hb is unlocked */ static int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags, @@ -2202,9 +2204,9 @@ pi_faulted: * the wakeup and return the appropriate error code to the caller. Must be * called with the hb lock held. * - * Returns - * 0 - no early wakeup detected - * <0 - -ETIMEDOUT or -ERESTARTNOINTR + * Return: + * 0 = no early wakeup detected; + * <0 = -ETIMEDOUT or -ERESTARTNOINTR */ static inline int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb, @@ -2246,7 +2248,6 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb, * @val: the expected value of uaddr * @abs_time: absolute timeout * @bitset: 32 bit wakeup bitset set by userspace, defaults to all - * @clockrt: whether to use CLOCK_REALTIME (1) or CLOCK_MONOTONIC (0) * @uaddr2: the pi futex we will take prior to returning to user-space * * The caller will wait on uaddr and will be requeued by futex_requeue() to @@ -2257,7 +2258,7 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb, * there was a need to. * * We call schedule in futex_wait_queue_me() when we enqueue and return there - * via the following: + * via the following-- * 1) wakeup on uaddr2 after an atomic lock acquisition by futex_requeue() * 2) wakeup on uaddr2 after a requeue * 3) signal @@ -2275,8 +2276,8 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb, * * If 4 or 7, we cleanup and return with -ETIMEDOUT. * - * Returns: - * 0 - On success + * Return: + * 0 - On success; * <0 - On error */ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, @@ -2471,8 +2472,6 @@ SYSCALL_DEFINE3(get_robust_list, int, pid, if (!futex_cmpxchg_enabled) return -ENOSYS; - WARN_ONCE(1, "deprecated: get_robust_list will be deleted in 2013.\n"); - rcu_read_lock(); ret = -ESRCH; diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c index 83e368b005fc..f9f44fd4d34d 100644 --- a/kernel/futex_compat.c +++ b/kernel/futex_compat.c @@ -11,6 +11,7 @@ #include <linux/nsproxy.h> #include <linux/futex.h> #include <linux/ptrace.h> +#include <linux/syscalls.h> #include <asm/uaccess.h> @@ -116,9 +117,9 @@ void compat_exit_robust_list(struct task_struct *curr) } } -asmlinkage long -compat_sys_set_robust_list(struct compat_robust_list_head __user *head, - compat_size_t len) +COMPAT_SYSCALL_DEFINE2(set_robust_list, + struct compat_robust_list_head __user *, head, + compat_size_t, len) { if (!futex_cmpxchg_enabled) return -ENOSYS; @@ -131,9 +132,9 @@ compat_sys_set_robust_list(struct compat_robust_list_head __user *head, return 0; } -asmlinkage long -compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr, - compat_size_t __user *len_ptr) +COMPAT_SYSCALL_DEFINE3(get_robust_list, int, pid, + compat_uptr_t __user *, head_ptr, + compat_size_t __user *, len_ptr) { struct compat_robust_list_head __user *head; unsigned long ret; @@ -142,8 +143,6 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr, if (!futex_cmpxchg_enabled) return -ENOSYS; - WARN_ONCE(1, "deprecated: get_robust_list will be deleted in 2013.\n"); - rcu_read_lock(); ret = -ESRCH; @@ -172,9 +171,9 @@ err_unlock: return ret; } -asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val, - struct compat_timespec __user *utime, u32 __user *uaddr2, - u32 val3) +COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val, + struct compat_timespec __user *, utime, u32 __user *, uaddr2, + u32, val3) { struct timespec ts; ktime_t t, *tp = NULL; diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig index a92028196cc1..d4da55d1fb65 100644 --- a/kernel/gcov/Kconfig +++ b/kernel/gcov/Kconfig @@ -35,7 +35,7 @@ config GCOV_KERNEL config GCOV_PROFILE_ALL bool "Profile entire Kernel" depends on GCOV_KERNEL - depends on SUPERH || S390 || X86 || (PPC && EXPERIMENTAL) || MICROBLAZE + depends on SUPERH || S390 || X86 || PPC || MICROBLAZE default n ---help--- This options activates profiling for the entire kernel. diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 6db7a5ed52b5..fd4b13b131f8 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -44,6 +44,8 @@ #include <linux/err.h> #include <linux/debugobjects.h> #include <linux/sched.h> +#include <linux/sched/sysctl.h> +#include <linux/sched/rt.h> #include <linux/timer.h> #include <asm/uaccess.h> @@ -61,6 +63,7 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = { + .lock = __RAW_SPIN_LOCK_UNLOCKED(hrtimer_bases.lock), .clock_base = { { @@ -81,6 +84,12 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = .get_time = &ktime_get_boottime, .resolution = KTIME_LOW_RES, }, + { + .index = HRTIMER_BASE_TAI, + .clockid = CLOCK_TAI, + .get_time = &ktime_get_clocktai, + .resolution = KTIME_LOW_RES, + }, } }; @@ -88,6 +97,7 @@ static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = { [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME, [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC, [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME, + [CLOCK_TAI] = HRTIMER_BASE_TAI, }; static inline int hrtimer_clockid_to_base(clockid_t clock_id) @@ -104,8 +114,10 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) { ktime_t xtim, mono, boot; struct timespec xts, tom, slp; + s32 tai_offset; get_xtime_and_monotonic_and_sleep_offset(&xts, &tom, &slp); + tai_offset = timekeeping_get_tai_offset(); xtim = timespec_to_ktime(xts); mono = ktime_add(xtim, timespec_to_ktime(tom)); @@ -113,6 +125,8 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) base->clock_base[HRTIMER_BASE_REALTIME].softirq_time = xtim; base->clock_base[HRTIMER_BASE_MONOTONIC].softirq_time = mono; base->clock_base[HRTIMER_BASE_BOOTTIME].softirq_time = boot; + base->clock_base[HRTIMER_BASE_TAI].softirq_time = + ktime_add(xtim, ktime_set(tai_offset, 0)); } /* @@ -158,7 +172,7 @@ struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer, */ static int hrtimer_get_target(int this_cpu, int pinned) { -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON if (!pinned && get_sysctl_timer_migration() && idle_cpu(this_cpu)) return get_nohz_timer_target(); #endif @@ -273,6 +287,10 @@ ktime_t ktime_add_ns(const ktime_t kt, u64 nsec) } else { unsigned long rem = do_div(nsec, NSEC_PER_SEC); + /* Make sure nsec fits into long */ + if (unlikely(nsec > KTIME_SEC_MAX)) + return (ktime_t){ .tv64 = KTIME_MAX }; + tmp = ktime_set((long)nsec, rem); } @@ -640,29 +658,18 @@ static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) * and expiry check is done in the hrtimer_interrupt or in the softirq. */ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, - struct hrtimer_clock_base *base, - int wakeup) + struct hrtimer_clock_base *base) { - if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) { - if (wakeup) { - raw_spin_unlock(&base->cpu_base->lock); - raise_softirq_irqoff(HRTIMER_SOFTIRQ); - raw_spin_lock(&base->cpu_base->lock); - } else - __raise_softirq_irqoff(HRTIMER_SOFTIRQ); - - return 1; - } - - return 0; + return base->cpu_base->hres_active && hrtimer_reprogram(timer, base); } static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base) { ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset; ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset; + ktime_t *offs_tai = &base->clock_base[HRTIMER_BASE_TAI].offset; - return ktime_get_update_offsets(offs_real, offs_boot); + return ktime_get_update_offsets(offs_real, offs_boot, offs_tai); } /* @@ -735,8 +742,7 @@ static inline int hrtimer_switch_to_hres(void) { return 0; } static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { } static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, - struct hrtimer_clock_base *base, - int wakeup) + struct hrtimer_clock_base *base) { return 0; } @@ -995,8 +1001,21 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, * * XXX send_remote_softirq() ? */ - if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases)) - hrtimer_enqueue_reprogram(timer, new_base, wakeup); + if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases) + && hrtimer_enqueue_reprogram(timer, new_base)) { + if (wakeup) { + /* + * We need to drop cpu_base->lock to avoid a + * lock ordering issue vs. rq->lock. + */ + raw_spin_unlock(&new_base->cpu_base->lock); + raise_softirq_irqoff(HRTIMER_SOFTIRQ); + local_irq_restore(flags); + return ret; + } else { + __raise_softirq_irqoff(HRTIMER_SOFTIRQ); + } + } unlock_hrtimer_base(timer, &flags); @@ -1008,7 +1027,8 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, * @timer: the timer to be added * @tim: expiry time * @delta_ns: "slack" range for the timer - * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL) + * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or + * relative (HRTIMER_MODE_REL) * * Returns: * 0 on success @@ -1025,7 +1045,8 @@ EXPORT_SYMBOL_GPL(hrtimer_start_range_ns); * hrtimer_start - (re)start an hrtimer on the current CPU * @timer: the timer to be added * @tim: expiry time - * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL) + * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or + * relative (HRTIMER_MODE_REL) * * Returns: * 0 on success @@ -1104,7 +1125,7 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer) } EXPORT_SYMBOL_GPL(hrtimer_get_remaining); -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON /** * hrtimer_get_next_event - get the time until next expiry event * @@ -1307,6 +1328,8 @@ retry: expires = ktime_sub(hrtimer_get_expires(timer), base->offset); + if (expires.tv64 < 0) + expires.tv64 = KTIME_MAX; if (expires.tv64 < expires_next.tv64) expires_next = expires; break; @@ -1640,8 +1663,6 @@ static void __cpuinit init_hrtimers_cpu(int cpu) struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); int i; - raw_spin_lock_init(&cpu_base->lock); - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { cpu_base->clock_base[i].cpu_base = cpu_base; timerqueue_init_head(&cpu_base->clock_base[i].active); diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 3aca9f29d30e..cbd97ce0b000 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -90,27 +90,41 @@ int irq_set_handler_data(unsigned int irq, void *data) EXPORT_SYMBOL(irq_set_handler_data); /** - * irq_set_msi_desc - set MSI descriptor data for an irq - * @irq: Interrupt number - * @entry: Pointer to MSI descriptor data + * irq_set_msi_desc_off - set MSI descriptor data for an irq at offset + * @irq_base: Interrupt number base + * @irq_offset: Interrupt number offset + * @entry: Pointer to MSI descriptor data * - * Set the MSI descriptor entry for an irq + * Set the MSI descriptor entry for an irq at offset */ -int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry) +int irq_set_msi_desc_off(unsigned int irq_base, unsigned int irq_offset, + struct msi_desc *entry) { unsigned long flags; - struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); + struct irq_desc *desc = irq_get_desc_lock(irq_base + irq_offset, &flags, IRQ_GET_DESC_CHECK_GLOBAL); if (!desc) return -EINVAL; desc->irq_data.msi_desc = entry; - if (entry) - entry->irq = irq; + if (entry && !irq_offset) + entry->irq = irq_base; irq_put_desc_unlock(desc, flags); return 0; } /** + * irq_set_msi_desc - set MSI descriptor data for an irq + * @irq: Interrupt number + * @entry: Pointer to MSI descriptor data + * + * Set the MSI descriptor entry for an irq + */ +int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry) +{ + return irq_set_msi_desc_off(irq, 0, entry); +} + +/** * irq_set_chip_data - set irq chip data for an irq * @irq: Interrupt number * @data: Pointer to chip specific data diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 96f3a1d9c379..5a83dde8ca0c 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -462,9 +462,23 @@ int irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base, if (domain->ops->map) { ret = domain->ops->map(domain, virq, hwirq); if (ret != 0) { - pr_err("irq-%i==>hwirq-0x%lx mapping failed: %d\n", - virq, hwirq, ret); - WARN_ON(1); + /* + * If map() returns -EPERM, this interrupt is protected + * by the firmware or some other service and shall not + * be mapped. + * + * Since on some platforms we blindly try to map everything + * we end up with a log full of backtraces. + * + * So instead, we silently fail on -EPERM, it is the + * responsibility of the PIC driver to display a relevant + * message if needed. + */ + if (ret != -EPERM) { + pr_err("irq-%i==>hwirq-0x%lx mapping failed: %d\n", + virq, hwirq, ret); + WARN_ON(1); + } irq_data->domain = NULL; irq_data->hwirq = 0; goto err_unmap; diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index e49a288fa479..fa17855ca65a 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -16,6 +16,7 @@ #include <linux/interrupt.h> #include <linux/slab.h> #include <linux/sched.h> +#include <linux/sched/rt.h> #include <linux/task_work.h> #include "internals.h" @@ -1524,6 +1525,7 @@ void enable_percpu_irq(unsigned int irq, unsigned int type) out: irq_put_desc_unlock(desc, flags); } +EXPORT_SYMBOL_GPL(enable_percpu_irq); void disable_percpu_irq(unsigned int irq) { @@ -1537,6 +1539,7 @@ void disable_percpu_irq(unsigned int irq) irq_percpu_disable(desc, cpu); irq_put_desc_unlock(desc, flags); } +EXPORT_SYMBOL_GPL(disable_percpu_irq); /* * Internal function to unregister a percpu irqaction. diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index 4bd4faa6323a..19ed5c425c3b 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -76,7 +76,7 @@ static int irq_affinity_list_proc_show(struct seq_file *m, void *v) static ssize_t write_irq_affinity(int type, struct file *file, const char __user *buffer, size_t count, loff_t *pos) { - unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data; + unsigned int irq = (int)(long)PDE_DATA(file_inode(file)); cpumask_var_t new_value; int err; @@ -131,17 +131,17 @@ static ssize_t irq_affinity_list_proc_write(struct file *file, static int irq_affinity_proc_open(struct inode *inode, struct file *file) { - return single_open(file, irq_affinity_proc_show, PDE(inode)->data); + return single_open(file, irq_affinity_proc_show, PDE_DATA(inode)); } static int irq_affinity_list_proc_open(struct inode *inode, struct file *file) { - return single_open(file, irq_affinity_list_proc_show, PDE(inode)->data); + return single_open(file, irq_affinity_list_proc_show, PDE_DATA(inode)); } static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file) { - return single_open(file, irq_affinity_hint_proc_show, PDE(inode)->data); + return single_open(file, irq_affinity_hint_proc_show, PDE_DATA(inode)); } static const struct file_operations irq_affinity_proc_fops = { @@ -212,7 +212,7 @@ out: static int default_affinity_open(struct inode *inode, struct file *file) { - return single_open(file, default_affinity_show, PDE(inode)->data); + return single_open(file, default_affinity_show, PDE_DATA(inode)); } static const struct file_operations default_affinity_proc_fops = { @@ -233,7 +233,7 @@ static int irq_node_proc_show(struct seq_file *m, void *v) static int irq_node_proc_open(struct inode *inode, struct file *file) { - return single_open(file, irq_node_proc_show, PDE(inode)->data); + return single_open(file, irq_node_proc_show, PDE_DATA(inode)); } static const struct file_operations irq_node_proc_fops = { @@ -256,7 +256,7 @@ static int irq_spurious_proc_show(struct seq_file *m, void *v) static int irq_spurious_proc_open(struct inode *inode, struct file *file) { - return single_open(file, irq_spurious_proc_show, PDE(inode)->data); + return single_open(file, irq_spurious_proc_show, PDE_DATA(inode)); } static const struct file_operations irq_spurious_proc_fops = { @@ -366,11 +366,7 @@ void unregister_irq_proc(unsigned int irq, struct irq_desc *desc) void unregister_handler_proc(unsigned int irq, struct irqaction *action) { - if (action->dir) { - struct irq_desc *desc = irq_to_desc(irq); - - remove_proc_entry(action->dir->name, desc->dir); - } + proc_remove(action->dir); } static void register_default_affinity_proc(void) diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 611cd6003c45..7b5f012bde9d 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -80,13 +80,11 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force) /* * All handlers must agree on IRQF_SHARED, so we test just the - * first. Check for action->next as well. + * first. */ action = desc->action; if (!action || !(action->flags & IRQF_SHARED) || - (action->flags & __IRQF_TIMER) || - (action->handler(irq, action->dev_id) == IRQ_HANDLED) || - !action->next) + (action->flags & __IRQF_TIMER)) goto out; /* Already running on another processor */ @@ -104,6 +102,7 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force) do { if (handle_irq_event(desc) == IRQ_HANDLED) ret = IRQ_HANDLED; + /* Make sure that there is still a valid action */ action = desc->action; } while ((desc->istate & IRQS_PENDING) && action); desc->istate &= ~IRQS_POLL_INPROGRESS; diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 1588e3b2871b..55fcce6065cf 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -12,37 +12,36 @@ #include <linux/percpu.h> #include <linux/hardirq.h> #include <linux/irqflags.h> +#include <linux/sched.h> +#include <linux/tick.h> +#include <linux/cpu.h> +#include <linux/notifier.h> #include <asm/processor.h> -/* - * An entry can be in one of four states: - * - * free NULL, 0 -> {claimed} : free to be used - * claimed NULL, 3 -> {pending} : claimed to be enqueued - * pending next, 3 -> {busy} : queued, pending callback - * busy NULL, 2 -> {free, claimed} : callback in progress, can be claimed - */ - -#define IRQ_WORK_PENDING 1UL -#define IRQ_WORK_BUSY 2UL -#define IRQ_WORK_FLAGS 3UL static DEFINE_PER_CPU(struct llist_head, irq_work_list); +static DEFINE_PER_CPU(int, irq_work_raised); /* * Claim the entry so that no one else will poke at it. */ static bool irq_work_claim(struct irq_work *work) { - unsigned long flags, nflags; + unsigned long flags, oflags, nflags; + /* + * Start with our best wish as a premise but only trust any + * flag value after cmpxchg() result. + */ + flags = work->flags & ~IRQ_WORK_PENDING; for (;;) { - flags = work->flags; - if (flags & IRQ_WORK_PENDING) - return false; nflags = flags | IRQ_WORK_FLAGS; - if (cmpxchg(&work->flags, flags, nflags) == flags) + oflags = cmpxchg(&work->flags, flags, nflags); + if (oflags == flags) break; + if (oflags & IRQ_WORK_PENDING) + return false; + flags = oflags; cpu_relax(); } @@ -57,57 +56,69 @@ void __weak arch_irq_work_raise(void) } /* - * Queue the entry and raise the IPI if needed. + * Enqueue the irq_work @entry unless it's already pending + * somewhere. + * + * Can be re-enqueued while the callback is still in progress. */ -static void __irq_work_queue(struct irq_work *work) +void irq_work_queue(struct irq_work *work) { - bool empty; + /* Only queue if not already pending */ + if (!irq_work_claim(work)) + return; + /* Queue the entry and raise the IPI if needed. */ preempt_disable(); - empty = llist_add(&work->llnode, &__get_cpu_var(irq_work_list)); - /* The list was empty, raise self-interrupt to start processing. */ - if (empty) - arch_irq_work_raise(); + llist_add(&work->llnode, &__get_cpu_var(irq_work_list)); + + /* + * If the work is not "lazy" or the tick is stopped, raise the irq + * work interrupt (if supported by the arch), otherwise, just wait + * for the next tick. + */ + if (!(work->flags & IRQ_WORK_LAZY) || tick_nohz_tick_stopped()) { + if (!this_cpu_cmpxchg(irq_work_raised, 0, 1)) + arch_irq_work_raise(); + } preempt_enable(); } +EXPORT_SYMBOL_GPL(irq_work_queue); -/* - * Enqueue the irq_work @entry, returns true on success, failure when the - * @entry was already enqueued by someone else. - * - * Can be re-enqueued while the callback is still in progress. - */ -bool irq_work_queue(struct irq_work *work) +bool irq_work_needs_cpu(void) { - if (!irq_work_claim(work)) { - /* - * Already enqueued, can't do! - */ + struct llist_head *this_list; + + this_list = &__get_cpu_var(irq_work_list); + if (llist_empty(this_list)) return false; - } - __irq_work_queue(work); + /* All work should have been flushed before going offline */ + WARN_ON_ONCE(cpu_is_offline(smp_processor_id())); + return true; } -EXPORT_SYMBOL_GPL(irq_work_queue); -/* - * Run the irq_work entries on this cpu. Requires to be ran from hardirq - * context with local IRQs disabled. - */ -void irq_work_run(void) +static void __irq_work_run(void) { + unsigned long flags; struct irq_work *work; struct llist_head *this_list; struct llist_node *llnode; + + /* + * Reset the "raised" state right before we check the list because + * an NMI may enqueue after we find the list empty from the runner. + */ + __this_cpu_write(irq_work_raised, 0); + barrier(); + this_list = &__get_cpu_var(irq_work_list); if (llist_empty(this_list)) return; - BUG_ON(!in_irq()); BUG_ON(!irqs_disabled()); llnode = llist_del_all(this_list); @@ -119,16 +130,31 @@ void irq_work_run(void) /* * Clear the PENDING bit, after this point the @work * can be re-used. + * Make it immediately visible so that other CPUs trying + * to claim that work don't rely on us to handle their data + * while we are in the middle of the func. */ - work->flags = IRQ_WORK_BUSY; + flags = work->flags & ~IRQ_WORK_PENDING; + xchg(&work->flags, flags); + work->func(work); /* * Clear the BUSY bit and return to the free state if * no-one else claimed it meanwhile. */ - (void)cmpxchg(&work->flags, IRQ_WORK_BUSY, 0); + (void)cmpxchg(&work->flags, flags, flags & ~IRQ_WORK_BUSY); } } + +/* + * Run the irq_work entries on this cpu. Requires to be ran from hardirq + * context with local IRQs disabled. + */ +void irq_work_run(void) +{ + BUG_ON(!in_irq()); + __irq_work_run(); +} EXPORT_SYMBOL_GPL(irq_work_run); /* @@ -143,3 +169,35 @@ void irq_work_sync(struct irq_work *work) cpu_relax(); } EXPORT_SYMBOL_GPL(irq_work_sync); + +#ifdef CONFIG_HOTPLUG_CPU +static int irq_work_cpu_notify(struct notifier_block *self, + unsigned long action, void *hcpu) +{ + long cpu = (long)hcpu; + + switch (action) { + case CPU_DYING: + /* Called from stop_machine */ + if (WARN_ON_ONCE(cpu != smp_processor_id())) + break; + __irq_work_run(); + break; + default: + break; + } + return NOTIFY_OK; +} + +static struct notifier_block cpu_notify; + +static __init int irq_work_init_cpu_notifier(void) +{ + cpu_notify.notifier_call = irq_work_cpu_notify; + cpu_notify.priority = 0; + register_cpu_notifier(&cpu_notify); + return 0; +} +device_initcall(irq_work_init_cpu_notifier); + +#endif /* CONFIG_HOTPLUG_CPU */ diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 2169feeba529..3127ad52cdb2 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -84,9 +84,11 @@ static int is_ksym_addr(unsigned long addr) /* * Expand a compressed symbol data into the resulting uncompressed string, + * if uncompressed string is too long (>= maxlen), it will be truncated, * given the offset to where the symbol is in the compressed stream. */ -static unsigned int kallsyms_expand_symbol(unsigned int off, char *result) +static unsigned int kallsyms_expand_symbol(unsigned int off, + char *result, size_t maxlen) { int len, skipped_first = 0; const u8 *tptr, *data; @@ -113,15 +115,20 @@ static unsigned int kallsyms_expand_symbol(unsigned int off, char *result) while (*tptr) { if (skipped_first) { + if (maxlen <= 1) + goto tail; *result = *tptr; result++; + maxlen--; } else skipped_first = 1; tptr++; } } - *result = '\0'; +tail: + if (maxlen) + *result = '\0'; /* Return to offset to the next symbol. */ return off; @@ -176,7 +183,7 @@ unsigned long kallsyms_lookup_name(const char *name) unsigned int off; for (i = 0, off = 0; i < kallsyms_num_syms; i++) { - off = kallsyms_expand_symbol(off, namebuf); + off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); if (strcmp(namebuf, name) == 0) return kallsyms_addresses[i]; @@ -195,7 +202,7 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, int ret; for (i = 0, off = 0; i < kallsyms_num_syms; i++) { - off = kallsyms_expand_symbol(off, namebuf); + off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); ret = fn(data, namebuf, NULL, kallsyms_addresses[i]); if (ret != 0) return ret; @@ -294,7 +301,8 @@ const char *kallsyms_lookup(unsigned long addr, pos = get_symbol_pos(addr, symbolsize, offset); /* Grab name */ - kallsyms_expand_symbol(get_symbol_offset(pos), namebuf); + kallsyms_expand_symbol(get_symbol_offset(pos), + namebuf, KSYM_NAME_LEN); if (modname) *modname = NULL; return namebuf; @@ -315,7 +323,8 @@ int lookup_symbol_name(unsigned long addr, char *symname) pos = get_symbol_pos(addr, NULL, NULL); /* Grab name */ - kallsyms_expand_symbol(get_symbol_offset(pos), symname); + kallsyms_expand_symbol(get_symbol_offset(pos), + symname, KSYM_NAME_LEN); return 0; } /* See if it's in a module. */ @@ -333,7 +342,8 @@ int lookup_symbol_attrs(unsigned long addr, unsigned long *size, pos = get_symbol_pos(addr, size, offset); /* Grab name */ - kallsyms_expand_symbol(get_symbol_offset(pos), name); + kallsyms_expand_symbol(get_symbol_offset(pos), + name, KSYM_NAME_LEN); modname[0] = '\0'; return 0; } @@ -463,7 +473,7 @@ static unsigned long get_ksymbol_core(struct kallsym_iter *iter) iter->type = kallsyms_get_symbol_type(off); - off = kallsyms_expand_symbol(off, iter->name); + off = kallsyms_expand_symbol(off, iter->name, ARRAY_SIZE(iter->name)); return off - iter->nameoff; } diff --git a/kernel/kexec.c b/kernel/kexec.c index 5e4bd7864c5d..59f7b55ba745 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -54,6 +54,12 @@ struct resource crashk_res = { .end = 0, .flags = IORESOURCE_BUSY | IORESOURCE_MEM }; +struct resource crashk_low_res = { + .name = "Crash kernel", + .start = 0, + .end = 0, + .flags = IORESOURCE_BUSY | IORESOURCE_MEM +}; int kexec_should_crash(struct task_struct *p) { @@ -223,6 +229,8 @@ out: } +static void kimage_free_page_list(struct list_head *list); + static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry, unsigned long nr_segments, struct kexec_segment __user *segments) @@ -236,8 +244,6 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry, if (result) goto out; - *rimage = image; - /* * Find a location for the control code buffer, and add it * the vector of segments so that it's pages will also be @@ -248,22 +254,22 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry, get_order(KEXEC_CONTROL_PAGE_SIZE)); if (!image->control_code_page) { printk(KERN_ERR "Could not allocate control_code_buffer\n"); - goto out; + goto out_free; } image->swap_page = kimage_alloc_control_pages(image, 0); if (!image->swap_page) { printk(KERN_ERR "Could not allocate swap buffer\n"); - goto out; + goto out_free; } - result = 0; - out: - if (result == 0) - *rimage = image; - else - kfree(image); + *rimage = image; + return 0; +out_free: + kimage_free_page_list(&image->control_pages); + kfree(image); +out: return result; } @@ -310,7 +316,7 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry, mend = mstart + image->segment[i].memsz - 1; /* Ensure we are within the crash kernel limits */ if ((mstart < crashk_res.start) || (mend > crashk_res.end)) - goto out; + goto out_free; } /* @@ -323,16 +329,15 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry, get_order(KEXEC_CONTROL_PAGE_SIZE)); if (!image->control_code_page) { printk(KERN_ERR "Could not allocate control_code_buffer\n"); - goto out; + goto out_free; } - result = 0; -out: - if (result == 0) - *rimage = image; - else - kfree(image); + *rimage = image; + return 0; +out_free: + kfree(image); +out: return result; } @@ -497,8 +502,6 @@ static struct page *kimage_alloc_crash_control_pages(struct kimage *image, if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT) break; - if (hole_end > crashk_res.end) - break; /* See if I overlap any of the segments */ for (i = 0; i < image->nr_segments; i++) { unsigned long mstart, mend; @@ -783,7 +786,7 @@ static int kimage_load_normal_segment(struct kimage *image, struct kexec_segment *segment) { unsigned long maddr; - unsigned long ubytes, mbytes; + size_t ubytes, mbytes; int result; unsigned char __user *buf; @@ -816,13 +819,9 @@ static int kimage_load_normal_segment(struct kimage *image, /* Start with a clear page */ clear_page(ptr); ptr += maddr & ~PAGE_MASK; - mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK); - if (mchunk > mbytes) - mchunk = mbytes; - - uchunk = mchunk; - if (uchunk > ubytes) - uchunk = ubytes; + mchunk = min_t(size_t, mbytes, + PAGE_SIZE - (maddr & ~PAGE_MASK)); + uchunk = min(ubytes, mchunk); result = copy_from_user(ptr, buf, uchunk); kunmap(page); @@ -847,7 +846,7 @@ static int kimage_load_crash_segment(struct kimage *image, * We do things a page at a time for the sake of kmap. */ unsigned long maddr; - unsigned long ubytes, mbytes; + size_t ubytes, mbytes; int result; unsigned char __user *buf; @@ -868,13 +867,10 @@ static int kimage_load_crash_segment(struct kimage *image, } ptr = kmap(page); ptr += maddr & ~PAGE_MASK; - mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK); - if (mchunk > mbytes) - mchunk = mbytes; - - uchunk = mchunk; - if (uchunk > ubytes) { - uchunk = ubytes; + mchunk = min_t(size_t, mbytes, + PAGE_SIZE - (maddr & ~PAGE_MASK)); + uchunk = min(ubytes, mchunk); + if (mchunk > uchunk) { /* Zero the trailing part of the page */ memset(ptr + uchunk, 0, mchunk - uchunk); } @@ -1115,12 +1111,8 @@ void __weak crash_free_reserved_phys_range(unsigned long begin, { unsigned long addr; - for (addr = begin; addr < end; addr += PAGE_SIZE) { - ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT)); - init_page_count(pfn_to_page(addr >> PAGE_SHIFT)); - free_page((unsigned long)__va(addr)); - totalram_pages++; - } + for (addr = begin; addr < end; addr += PAGE_SIZE) + free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT)); } int crash_shrink_memory(unsigned long new_size) @@ -1365,34 +1357,114 @@ static int __init parse_crashkernel_simple(char *cmdline, return 0; } +#define SUFFIX_HIGH 0 +#define SUFFIX_LOW 1 +#define SUFFIX_NULL 2 +static __initdata char *suffix_tbl[] = { + [SUFFIX_HIGH] = ",high", + [SUFFIX_LOW] = ",low", + [SUFFIX_NULL] = NULL, +}; + /* - * That function is the entry point for command line parsing and should be - * called from the arch-specific code. + * That function parses "suffix" crashkernel command lines like + * + * crashkernel=size,[high|low] + * + * It returns 0 on success and -EINVAL on failure. */ -int __init parse_crashkernel(char *cmdline, +static int __init parse_crashkernel_suffix(char *cmdline, + unsigned long long *crash_size, + unsigned long long *crash_base, + const char *suffix) +{ + char *cur = cmdline; + + *crash_size = memparse(cmdline, &cur); + if (cmdline == cur) { + pr_warn("crashkernel: memory value expected\n"); + return -EINVAL; + } + + /* check with suffix */ + if (strncmp(cur, suffix, strlen(suffix))) { + pr_warn("crashkernel: unrecognized char\n"); + return -EINVAL; + } + cur += strlen(suffix); + if (*cur != ' ' && *cur != '\0') { + pr_warn("crashkernel: unrecognized char\n"); + return -EINVAL; + } + + return 0; +} + +static __init char *get_last_crashkernel(char *cmdline, + const char *name, + const char *suffix) +{ + char *p = cmdline, *ck_cmdline = NULL; + + /* find crashkernel and use the last one if there are more */ + p = strstr(p, name); + while (p) { + char *end_p = strchr(p, ' '); + char *q; + + if (!end_p) + end_p = p + strlen(p); + + if (!suffix) { + int i; + + /* skip the one with any known suffix */ + for (i = 0; suffix_tbl[i]; i++) { + q = end_p - strlen(suffix_tbl[i]); + if (!strncmp(q, suffix_tbl[i], + strlen(suffix_tbl[i]))) + goto next; + } + ck_cmdline = p; + } else { + q = end_p - strlen(suffix); + if (!strncmp(q, suffix, strlen(suffix))) + ck_cmdline = p; + } +next: + p = strstr(p+1, name); + } + + if (!ck_cmdline) + return NULL; + + return ck_cmdline; +} + +static int __init __parse_crashkernel(char *cmdline, unsigned long long system_ram, unsigned long long *crash_size, - unsigned long long *crash_base) + unsigned long long *crash_base, + const char *name, + const char *suffix) { - char *p = cmdline, *ck_cmdline = NULL; char *first_colon, *first_space; + char *ck_cmdline; BUG_ON(!crash_size || !crash_base); *crash_size = 0; *crash_base = 0; - /* find crashkernel and use the last one if there are more */ - p = strstr(p, "crashkernel="); - while (p) { - ck_cmdline = p; - p = strstr(p+1, "crashkernel="); - } + ck_cmdline = get_last_crashkernel(cmdline, name, suffix); if (!ck_cmdline) return -EINVAL; - ck_cmdline += 12; /* strlen("crashkernel=") */ + ck_cmdline += strlen(name); + if (suffix) + return parse_crashkernel_suffix(ck_cmdline, crash_size, + crash_base, suffix); /* * if the commandline contains a ':', then that's the extended * syntax -- if not, it must be the classic syntax @@ -1409,6 +1481,36 @@ int __init parse_crashkernel(char *cmdline, return 0; } +/* + * That function is the entry point for command line parsing and should be + * called from the arch-specific code. + */ +int __init parse_crashkernel(char *cmdline, + unsigned long long system_ram, + unsigned long long *crash_size, + unsigned long long *crash_base) +{ + return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, + "crashkernel=", NULL); +} + +int __init parse_crashkernel_high(char *cmdline, + unsigned long long system_ram, + unsigned long long *crash_size, + unsigned long long *crash_base) +{ + return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, + "crashkernel=", suffix_tbl[SUFFIX_HIGH]); +} + +int __init parse_crashkernel_low(char *cmdline, + unsigned long long system_ram, + unsigned long long *crash_size, + unsigned long long *crash_base) +{ + return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, + "crashkernel=", suffix_tbl[SUFFIX_LOW]); +} static void update_vmcoreinfo_note(void) { @@ -1431,14 +1533,13 @@ void vmcoreinfo_append_str(const char *fmt, ...) { va_list args; char buf[0x50]; - int r; + size_t r; va_start(args, fmt); r = vsnprintf(buf, sizeof(buf), fmt, args); va_end(args); - if (r + vmcoreinfo_size > vmcoreinfo_max_size) - r = vmcoreinfo_max_size - vmcoreinfo_size; + r = min(r, vmcoreinfo_max_size - vmcoreinfo_size); memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r); @@ -1468,7 +1569,7 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_SYMBOL(swapper_pg_dir); #endif VMCOREINFO_SYMBOL(_stext); - VMCOREINFO_SYMBOL(vmlist); + VMCOREINFO_SYMBOL(vmap_area_list); #ifndef CONFIG_NEED_MULTIPLE_NODES VMCOREINFO_SYMBOL(mem_map); @@ -1490,6 +1591,8 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_OFFSET(page, _count); VMCOREINFO_OFFSET(page, mapping); VMCOREINFO_OFFSET(page, lru); + VMCOREINFO_OFFSET(page, _mapcount); + VMCOREINFO_OFFSET(page, private); VMCOREINFO_OFFSET(pglist_data, node_zones); VMCOREINFO_OFFSET(pglist_data, nr_zones); #ifdef CONFIG_FLAT_NODE_MEM_MAP @@ -1504,7 +1607,8 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_OFFSET(free_area, free_list); VMCOREINFO_OFFSET(list_head, next); VMCOREINFO_OFFSET(list_head, prev); - VMCOREINFO_OFFSET(vm_struct, addr); + VMCOREINFO_OFFSET(vmap_area, va_start); + VMCOREINFO_OFFSET(vmap_area, list); VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER); log_buf_kexec_setup(); VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); @@ -1512,6 +1616,11 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_NUMBER(PG_lru); VMCOREINFO_NUMBER(PG_private); VMCOREINFO_NUMBER(PG_swapcache); + VMCOREINFO_NUMBER(PG_slab); +#ifdef CONFIG_MEMORY_FAILURE + VMCOREINFO_NUMBER(PG_hwpoison); +#endif + VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); arch_crash_save_vmcoreinfo(); update_vmcoreinfo_note(); diff --git a/kernel/kfifo.c b/kernel/kfifo.c deleted file mode 100644 index 59dcf5b81d24..000000000000 --- a/kernel/kfifo.c +++ /dev/null @@ -1,609 +0,0 @@ -/* - * A generic kernel FIFO implementation - * - * Copyright (C) 2009/2010 Stefani Seibold <stefani@seibold.net> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - * - */ - -#include <linux/kernel.h> -#include <linux/export.h> -#include <linux/slab.h> -#include <linux/err.h> -#include <linux/log2.h> -#include <linux/uaccess.h> -#include <linux/kfifo.h> - -/* - * internal helper to calculate the unused elements in a fifo - */ -static inline unsigned int kfifo_unused(struct __kfifo *fifo) -{ - return (fifo->mask + 1) - (fifo->in - fifo->out); -} - -int __kfifo_alloc(struct __kfifo *fifo, unsigned int size, - size_t esize, gfp_t gfp_mask) -{ - /* - * round down to the next power of 2, since our 'let the indices - * wrap' technique works only in this case. - */ - if (!is_power_of_2(size)) - size = rounddown_pow_of_two(size); - - fifo->in = 0; - fifo->out = 0; - fifo->esize = esize; - - if (size < 2) { - fifo->data = NULL; - fifo->mask = 0; - return -EINVAL; - } - - fifo->data = kmalloc(size * esize, gfp_mask); - - if (!fifo->data) { - fifo->mask = 0; - return -ENOMEM; - } - fifo->mask = size - 1; - - return 0; -} -EXPORT_SYMBOL(__kfifo_alloc); - -void __kfifo_free(struct __kfifo *fifo) -{ - kfree(fifo->data); - fifo->in = 0; - fifo->out = 0; - fifo->esize = 0; - fifo->data = NULL; - fifo->mask = 0; -} -EXPORT_SYMBOL(__kfifo_free); - -int __kfifo_init(struct __kfifo *fifo, void *buffer, - unsigned int size, size_t esize) -{ - size /= esize; - - if (!is_power_of_2(size)) - size = rounddown_pow_of_two(size); - - fifo->in = 0; - fifo->out = 0; - fifo->esize = esize; - fifo->data = buffer; - - if (size < 2) { - fifo->mask = 0; - return -EINVAL; - } - fifo->mask = size - 1; - - return 0; -} -EXPORT_SYMBOL(__kfifo_init); - -static void kfifo_copy_in(struct __kfifo *fifo, const void *src, - unsigned int len, unsigned int off) -{ - unsigned int size = fifo->mask + 1; - unsigned int esize = fifo->esize; - unsigned int l; - - off &= fifo->mask; - if (esize != 1) { - off *= esize; - size *= esize; - len *= esize; - } - l = min(len, size - off); - - memcpy(fifo->data + off, src, l); - memcpy(fifo->data, src + l, len - l); - /* - * make sure that the data in the fifo is up to date before - * incrementing the fifo->in index counter - */ - smp_wmb(); -} - -unsigned int __kfifo_in(struct __kfifo *fifo, - const void *buf, unsigned int len) -{ - unsigned int l; - - l = kfifo_unused(fifo); - if (len > l) - len = l; - - kfifo_copy_in(fifo, buf, len, fifo->in); - fifo->in += len; - return len; -} -EXPORT_SYMBOL(__kfifo_in); - -static void kfifo_copy_out(struct __kfifo *fifo, void *dst, - unsigned int len, unsigned int off) -{ - unsigned int size = fifo->mask + 1; - unsigned int esize = fifo->esize; - unsigned int l; - - off &= fifo->mask; - if (esize != 1) { - off *= esize; - size *= esize; - len *= esize; - } - l = min(len, size - off); - - memcpy(dst, fifo->data + off, l); - memcpy(dst + l, fifo->data, len - l); - /* - * make sure that the data is copied before - * incrementing the fifo->out index counter - */ - smp_wmb(); -} - -unsigned int __kfifo_out_peek(struct __kfifo *fifo, - void *buf, unsigned int len) -{ - unsigned int l; - - l = fifo->in - fifo->out; - if (len > l) - len = l; - - kfifo_copy_out(fifo, buf, len, fifo->out); - return len; -} -EXPORT_SYMBOL(__kfifo_out_peek); - -unsigned int __kfifo_out(struct __kfifo *fifo, - void *buf, unsigned int len) -{ - len = __kfifo_out_peek(fifo, buf, len); - fifo->out += len; - return len; -} -EXPORT_SYMBOL(__kfifo_out); - -static unsigned long kfifo_copy_from_user(struct __kfifo *fifo, - const void __user *from, unsigned int len, unsigned int off, - unsigned int *copied) -{ - unsigned int size = fifo->mask + 1; - unsigned int esize = fifo->esize; - unsigned int l; - unsigned long ret; - - off &= fifo->mask; - if (esize != 1) { - off *= esize; - size *= esize; - len *= esize; - } - l = min(len, size - off); - - ret = copy_from_user(fifo->data + off, from, l); - if (unlikely(ret)) - ret = DIV_ROUND_UP(ret + len - l, esize); - else { - ret = copy_from_user(fifo->data, from + l, len - l); - if (unlikely(ret)) - ret = DIV_ROUND_UP(ret, esize); - } - /* - * make sure that the data in the fifo is up to date before - * incrementing the fifo->in index counter - */ - smp_wmb(); - *copied = len - ret; - /* return the number of elements which are not copied */ - return ret; -} - -int __kfifo_from_user(struct __kfifo *fifo, const void __user *from, - unsigned long len, unsigned int *copied) -{ - unsigned int l; - unsigned long ret; - unsigned int esize = fifo->esize; - int err; - - if (esize != 1) - len /= esize; - - l = kfifo_unused(fifo); - if (len > l) - len = l; - - ret = kfifo_copy_from_user(fifo, from, len, fifo->in, copied); - if (unlikely(ret)) { - len -= ret; - err = -EFAULT; - } else - err = 0; - fifo->in += len; - return err; -} -EXPORT_SYMBOL(__kfifo_from_user); - -static unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to, - unsigned int len, unsigned int off, unsigned int *copied) -{ - unsigned int l; - unsigned long ret; - unsigned int size = fifo->mask + 1; - unsigned int esize = fifo->esize; - - off &= fifo->mask; - if (esize != 1) { - off *= esize; - size *= esize; - len *= esize; - } - l = min(len, size - off); - - ret = copy_to_user(to, fifo->data + off, l); - if (unlikely(ret)) - ret = DIV_ROUND_UP(ret + len - l, esize); - else { - ret = copy_to_user(to + l, fifo->data, len - l); - if (unlikely(ret)) - ret = DIV_ROUND_UP(ret, esize); - } - /* - * make sure that the data is copied before - * incrementing the fifo->out index counter - */ - smp_wmb(); - *copied = len - ret; - /* return the number of elements which are not copied */ - return ret; -} - -int __kfifo_to_user(struct __kfifo *fifo, void __user *to, - unsigned long len, unsigned int *copied) -{ - unsigned int l; - unsigned long ret; - unsigned int esize = fifo->esize; - int err; - - if (esize != 1) - len /= esize; - - l = fifo->in - fifo->out; - if (len > l) - len = l; - ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied); - if (unlikely(ret)) { - len -= ret; - err = -EFAULT; - } else - err = 0; - fifo->out += len; - return err; -} -EXPORT_SYMBOL(__kfifo_to_user); - -static int setup_sgl_buf(struct scatterlist *sgl, void *buf, - int nents, unsigned int len) -{ - int n; - unsigned int l; - unsigned int off; - struct page *page; - - if (!nents) - return 0; - - if (!len) - return 0; - - n = 0; - page = virt_to_page(buf); - off = offset_in_page(buf); - l = 0; - - while (len >= l + PAGE_SIZE - off) { - struct page *npage; - - l += PAGE_SIZE; - buf += PAGE_SIZE; - npage = virt_to_page(buf); - if (page_to_phys(page) != page_to_phys(npage) - l) { - sg_set_page(sgl, page, l - off, off); - sgl = sg_next(sgl); - if (++n == nents || sgl == NULL) - return n; - page = npage; - len -= l - off; - l = off = 0; - } - } - sg_set_page(sgl, page, len, off); - return n + 1; -} - -static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl, - int nents, unsigned int len, unsigned int off) -{ - unsigned int size = fifo->mask + 1; - unsigned int esize = fifo->esize; - unsigned int l; - unsigned int n; - - off &= fifo->mask; - if (esize != 1) { - off *= esize; - size *= esize; - len *= esize; - } - l = min(len, size - off); - - n = setup_sgl_buf(sgl, fifo->data + off, nents, l); - n += setup_sgl_buf(sgl + n, fifo->data, nents - n, len - l); - - return n; -} - -unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo, - struct scatterlist *sgl, int nents, unsigned int len) -{ - unsigned int l; - - l = kfifo_unused(fifo); - if (len > l) - len = l; - - return setup_sgl(fifo, sgl, nents, len, fifo->in); -} -EXPORT_SYMBOL(__kfifo_dma_in_prepare); - -unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo, - struct scatterlist *sgl, int nents, unsigned int len) -{ - unsigned int l; - - l = fifo->in - fifo->out; - if (len > l) - len = l; - - return setup_sgl(fifo, sgl, nents, len, fifo->out); -} -EXPORT_SYMBOL(__kfifo_dma_out_prepare); - -unsigned int __kfifo_max_r(unsigned int len, size_t recsize) -{ - unsigned int max = (1 << (recsize << 3)) - 1; - - if (len > max) - return max; - return len; -} -EXPORT_SYMBOL(__kfifo_max_r); - -#define __KFIFO_PEEK(data, out, mask) \ - ((data)[(out) & (mask)]) -/* - * __kfifo_peek_n internal helper function for determinate the length of - * the next record in the fifo - */ -static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize) -{ - unsigned int l; - unsigned int mask = fifo->mask; - unsigned char *data = fifo->data; - - l = __KFIFO_PEEK(data, fifo->out, mask); - - if (--recsize) - l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8; - - return l; -} - -#define __KFIFO_POKE(data, in, mask, val) \ - ( \ - (data)[(in) & (mask)] = (unsigned char)(val) \ - ) - -/* - * __kfifo_poke_n internal helper function for storeing the length of - * the record into the fifo - */ -static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize) -{ - unsigned int mask = fifo->mask; - unsigned char *data = fifo->data; - - __KFIFO_POKE(data, fifo->in, mask, n); - - if (recsize > 1) - __KFIFO_POKE(data, fifo->in + 1, mask, n >> 8); -} - -unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize) -{ - return __kfifo_peek_n(fifo, recsize); -} -EXPORT_SYMBOL(__kfifo_len_r); - -unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf, - unsigned int len, size_t recsize) -{ - if (len + recsize > kfifo_unused(fifo)) - return 0; - - __kfifo_poke_n(fifo, len, recsize); - - kfifo_copy_in(fifo, buf, len, fifo->in + recsize); - fifo->in += len + recsize; - return len; -} -EXPORT_SYMBOL(__kfifo_in_r); - -static unsigned int kfifo_out_copy_r(struct __kfifo *fifo, - void *buf, unsigned int len, size_t recsize, unsigned int *n) -{ - *n = __kfifo_peek_n(fifo, recsize); - - if (len > *n) - len = *n; - - kfifo_copy_out(fifo, buf, len, fifo->out + recsize); - return len; -} - -unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, void *buf, - unsigned int len, size_t recsize) -{ - unsigned int n; - - if (fifo->in == fifo->out) - return 0; - - return kfifo_out_copy_r(fifo, buf, len, recsize, &n); -} -EXPORT_SYMBOL(__kfifo_out_peek_r); - -unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf, - unsigned int len, size_t recsize) -{ - unsigned int n; - - if (fifo->in == fifo->out) - return 0; - - len = kfifo_out_copy_r(fifo, buf, len, recsize, &n); - fifo->out += n + recsize; - return len; -} -EXPORT_SYMBOL(__kfifo_out_r); - -void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize) -{ - unsigned int n; - - n = __kfifo_peek_n(fifo, recsize); - fifo->out += n + recsize; -} -EXPORT_SYMBOL(__kfifo_skip_r); - -int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from, - unsigned long len, unsigned int *copied, size_t recsize) -{ - unsigned long ret; - - len = __kfifo_max_r(len, recsize); - - if (len + recsize > kfifo_unused(fifo)) { - *copied = 0; - return 0; - } - - __kfifo_poke_n(fifo, len, recsize); - - ret = kfifo_copy_from_user(fifo, from, len, fifo->in + recsize, copied); - if (unlikely(ret)) { - *copied = 0; - return -EFAULT; - } - fifo->in += len + recsize; - return 0; -} -EXPORT_SYMBOL(__kfifo_from_user_r); - -int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to, - unsigned long len, unsigned int *copied, size_t recsize) -{ - unsigned long ret; - unsigned int n; - - if (fifo->in == fifo->out) { - *copied = 0; - return 0; - } - - n = __kfifo_peek_n(fifo, recsize); - if (len > n) - len = n; - - ret = kfifo_copy_to_user(fifo, to, len, fifo->out + recsize, copied); - if (unlikely(ret)) { - *copied = 0; - return -EFAULT; - } - fifo->out += n + recsize; - return 0; -} -EXPORT_SYMBOL(__kfifo_to_user_r); - -unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo, - struct scatterlist *sgl, int nents, unsigned int len, size_t recsize) -{ - if (!nents) - BUG(); - - len = __kfifo_max_r(len, recsize); - - if (len + recsize > kfifo_unused(fifo)) - return 0; - - return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize); -} -EXPORT_SYMBOL(__kfifo_dma_in_prepare_r); - -void __kfifo_dma_in_finish_r(struct __kfifo *fifo, - unsigned int len, size_t recsize) -{ - len = __kfifo_max_r(len, recsize); - __kfifo_poke_n(fifo, len, recsize); - fifo->in += len + recsize; -} -EXPORT_SYMBOL(__kfifo_dma_in_finish_r); - -unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo, - struct scatterlist *sgl, int nents, unsigned int len, size_t recsize) -{ - if (!nents) - BUG(); - - len = __kfifo_max_r(len, recsize); - - if (len + recsize > fifo->in - fifo->out) - return 0; - - return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize); -} -EXPORT_SYMBOL(__kfifo_dma_out_prepare_r); - -void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize) -{ - unsigned int len; - - len = __kfifo_peek_n(fifo, recsize); - fifo->out += len + recsize; -} -EXPORT_SYMBOL(__kfifo_dma_out_finish_r); diff --git a/kernel/kmod.c b/kernel/kmod.c index 0023a87e8de6..1296e72e4161 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -38,6 +38,7 @@ #include <linux/suspend.h> #include <linux/rwsem.h> #include <linux/ptrace.h> +#include <linux/async.h> #include <asm/uaccess.h> #include <trace/events/module.h> @@ -76,6 +77,7 @@ static void free_modprobe_argv(struct subprocess_info *info) static int call_modprobe(char *module_name, int wait) { + struct subprocess_info *info; static char *envp[] = { "HOME=/", "TERM=linux", @@ -97,8 +99,15 @@ static int call_modprobe(char *module_name, int wait) argv[3] = module_name; /* check free_modprobe_argv() */ argv[4] = NULL; - return call_usermodehelper_fns(modprobe_path, argv, envp, - wait | UMH_KILLABLE, NULL, free_modprobe_argv, NULL); + info = call_usermodehelper_setup(modprobe_path, argv, envp, GFP_KERNEL, + NULL, free_modprobe_argv, NULL); + if (!info) + goto free_module_name; + + return call_usermodehelper_exec(info, wait | UMH_KILLABLE); + +free_module_name: + kfree(module_name); free_argv: kfree(argv); out: @@ -130,6 +139,14 @@ int __request_module(bool wait, const char *fmt, ...) #define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */ static int kmod_loop_msg; + /* + * We don't allow synchronous module loading from async. Module + * init may invoke async_synchronize_full() which will end up + * waiting for this task which already is waiting for the module + * loading to complete, leading to a deadlock. + */ + WARN_ON_ONCE(wait && current_is_async()); + va_start(args, fmt); ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args); va_end(args); @@ -493,14 +510,28 @@ static void helper_unlock(void) * @argv: arg vector for process * @envp: environment for process * @gfp_mask: gfp mask for memory allocation + * @cleanup: a cleanup function + * @init: an init function + * @data: arbitrary context sensitive data * * Returns either %NULL on allocation failure, or a subprocess_info * structure. This should be passed to call_usermodehelper_exec to * exec the process and free the structure. + * + * The init function is used to customize the helper process prior to + * exec. A non-zero return code causes the process to error out, exit, + * and return the failure to the calling process + * + * The cleanup function is just before ethe subprocess_info is about to + * be freed. This can be used for freeing the argv and envp. The + * Function must be runnable in either a process context or the + * context in which call_usermodehelper_exec is called. */ -static struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, - char **envp, gfp_t gfp_mask) + char **envp, gfp_t gfp_mask, + int (*init)(struct subprocess_info *info, struct cred *new), + void (*cleanup)(struct subprocess_info *info), + void *data) { struct subprocess_info *sub_info; sub_info = kzalloc(sizeof(struct subprocess_info), gfp_mask); @@ -511,50 +542,27 @@ struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, sub_info->path = path; sub_info->argv = argv; sub_info->envp = envp; + + sub_info->cleanup = cleanup; + sub_info->init = init; + sub_info->data = data; out: return sub_info; } - -/** - * call_usermodehelper_setfns - set a cleanup/init function - * @info: a subprocess_info returned by call_usermodehelper_setup - * @cleanup: a cleanup function - * @init: an init function - * @data: arbitrary context sensitive data - * - * The init function is used to customize the helper process prior to - * exec. A non-zero return code causes the process to error out, exit, - * and return the failure to the calling process - * - * The cleanup function is just before ethe subprocess_info is about to - * be freed. This can be used for freeing the argv and envp. The - * Function must be runnable in either a process context or the - * context in which call_usermodehelper_exec is called. - */ -static -void call_usermodehelper_setfns(struct subprocess_info *info, - int (*init)(struct subprocess_info *info, struct cred *new), - void (*cleanup)(struct subprocess_info *info), - void *data) -{ - info->cleanup = cleanup; - info->init = init; - info->data = data; -} +EXPORT_SYMBOL(call_usermodehelper_setup); /** * call_usermodehelper_exec - start a usermode application * @sub_info: information about the subprocessa * @wait: wait for the application to finish and return status. - * when -1 don't wait at all, but you get no useful error back when - * the program couldn't be exec'ed. This makes it safe to call + * when UMH_NO_WAIT don't wait at all, but you get no useful error back + * when the program couldn't be exec'ed. This makes it safe to call * from interrupt context. * * Runs a user-space application. The application is started * asynchronously if wait is not set, and runs as a child of keventd. * (ie. it runs with full root capabilities). */ -static int call_usermodehelper_exec(struct subprocess_info *sub_info, int wait) { DECLARE_COMPLETION_ONSTACK(done); @@ -606,31 +614,34 @@ unlock: helper_unlock(); return retval; } +EXPORT_SYMBOL(call_usermodehelper_exec); -/* - * call_usermodehelper_fns() will not run the caller-provided cleanup function - * if a memory allocation failure is experienced. So the caller might need to - * check the call_usermodehelper_fns() return value: if it is -ENOMEM, perform - * the necessaary cleanup within the caller. +/** + * call_usermodehelper() - prepare and start a usermode application + * @path: path to usermode executable + * @argv: arg vector for process + * @envp: environment for process + * @wait: wait for the application to finish and return status. + * when UMH_NO_WAIT don't wait at all, but you get no useful error back + * when the program couldn't be exec'ed. This makes it safe to call + * from interrupt context. + * + * This function is the equivalent to use call_usermodehelper_setup() and + * call_usermodehelper_exec(). */ -int call_usermodehelper_fns( - char *path, char **argv, char **envp, int wait, - int (*init)(struct subprocess_info *info, struct cred *new), - void (*cleanup)(struct subprocess_info *), void *data) +int call_usermodehelper(char *path, char **argv, char **envp, int wait) { struct subprocess_info *info; gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL; - info = call_usermodehelper_setup(path, argv, envp, gfp_mask); - + info = call_usermodehelper_setup(path, argv, envp, gfp_mask, + NULL, NULL, NULL); if (info == NULL) return -ENOMEM; - call_usermodehelper_setfns(info, init, cleanup, data); - return call_usermodehelper_exec(info, wait); } -EXPORT_SYMBOL(call_usermodehelper_fns); +EXPORT_SYMBOL(call_usermodehelper); static int proc_cap_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 098f396aa409..3fed7f0cbcdf 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -334,11 +334,10 @@ static inline void reset_kprobe_instance(void) struct kprobe __kprobes *get_kprobe(void *addr) { struct hlist_head *head; - struct hlist_node *node; struct kprobe *p; head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; - hlist_for_each_entry_rcu(p, node, head, hlist) { + hlist_for_each_entry_rcu(p, head, hlist) { if (p->addr == addr) return p; } @@ -471,7 +470,6 @@ static LIST_HEAD(unoptimizing_list); static void kprobe_optimizer(struct work_struct *work); static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); -static DECLARE_COMPLETION(optimizer_comp); #define OPTIMIZE_DELAY 5 /* @@ -552,8 +550,7 @@ static __kprobes void do_free_cleaned_kprobes(struct list_head *free_list) /* Start optimizer after OPTIMIZE_DELAY passed */ static __kprobes void kick_kprobe_optimizer(void) { - if (!delayed_work_pending(&optimizing_work)) - schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); + schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); } /* Kprobe jump optimizer */ @@ -592,16 +589,25 @@ static __kprobes void kprobe_optimizer(struct work_struct *work) /* Step 5: Kick optimizer again if needed */ if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) kick_kprobe_optimizer(); - else - /* Wake up all waiters */ - complete_all(&optimizer_comp); } /* Wait for completing optimization and unoptimization */ static __kprobes void wait_for_kprobe_optimizer(void) { - if (delayed_work_pending(&optimizing_work)) - wait_for_completion(&optimizer_comp); + mutex_lock(&kprobe_mutex); + + while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) { + mutex_unlock(&kprobe_mutex); + + /* this will also make optimizing_work execute immmediately */ + flush_delayed_work(&optimizing_work); + /* @optimizing_work might not have been queued yet, relax */ + cpu_relax(); + + mutex_lock(&kprobe_mutex); + } + + mutex_unlock(&kprobe_mutex); } /* Optimize kprobe if p is ready to be optimized */ @@ -788,53 +794,58 @@ out: } #ifdef CONFIG_SYSCTL -/* This should be called with kprobe_mutex locked */ static void __kprobes optimize_all_kprobes(void) { struct hlist_head *head; - struct hlist_node *node; struct kprobe *p; unsigned int i; + mutex_lock(&kprobe_mutex); /* If optimization is already allowed, just return */ if (kprobes_allow_optimization) - return; + goto out; kprobes_allow_optimization = true; for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; - hlist_for_each_entry_rcu(p, node, head, hlist) + hlist_for_each_entry_rcu(p, head, hlist) if (!kprobe_disabled(p)) optimize_kprobe(p); } printk(KERN_INFO "Kprobes globally optimized\n"); +out: + mutex_unlock(&kprobe_mutex); } -/* This should be called with kprobe_mutex locked */ static void __kprobes unoptimize_all_kprobes(void) { struct hlist_head *head; - struct hlist_node *node; struct kprobe *p; unsigned int i; + mutex_lock(&kprobe_mutex); /* If optimization is already prohibited, just return */ - if (!kprobes_allow_optimization) + if (!kprobes_allow_optimization) { + mutex_unlock(&kprobe_mutex); return; + } kprobes_allow_optimization = false; for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; - hlist_for_each_entry_rcu(p, node, head, hlist) { + hlist_for_each_entry_rcu(p, head, hlist) { if (!kprobe_disabled(p)) unoptimize_kprobe(p, false); } } + mutex_unlock(&kprobe_mutex); + /* Wait for unoptimizing completion */ wait_for_kprobe_optimizer(); printk(KERN_INFO "Kprobes globally unoptimized\n"); } +static DEFINE_MUTEX(kprobe_sysctl_mutex); int sysctl_kprobes_optimization; int proc_kprobes_optimization_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, @@ -842,7 +853,7 @@ int proc_kprobes_optimization_handler(struct ctl_table *table, int write, { int ret; - mutex_lock(&kprobe_mutex); + mutex_lock(&kprobe_sysctl_mutex); sysctl_kprobes_optimization = kprobes_allow_optimization ? 1 : 0; ret = proc_dointvec_minmax(table, write, buffer, length, ppos); @@ -850,7 +861,7 @@ int proc_kprobes_optimization_handler(struct ctl_table *table, int write, optimize_all_kprobes(); else unoptimize_all_kprobes(); - mutex_unlock(&kprobe_mutex); + mutex_unlock(&kprobe_sysctl_mutex); return ret; } @@ -919,7 +930,7 @@ static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p) } #endif /* CONFIG_OPTPROBES */ -#ifdef KPROBES_CAN_USE_FTRACE +#ifdef CONFIG_KPROBES_ON_FTRACE static struct ftrace_ops kprobe_ftrace_ops __read_mostly = { .func = kprobe_ftrace_handler, .flags = FTRACE_OPS_FL_SAVE_REGS, @@ -964,7 +975,7 @@ static void __kprobes disarm_kprobe_ftrace(struct kprobe *p) (unsigned long)p->addr, 1, 0); WARN(ret < 0, "Failed to disarm kprobe-ftrace at %p (%d)\n", p->addr, ret); } -#else /* !KPROBES_CAN_USE_FTRACE */ +#else /* !CONFIG_KPROBES_ON_FTRACE */ #define prepare_kprobe(p) arch_prepare_kprobe(p) #define arm_kprobe_ftrace(p) do {} while (0) #define disarm_kprobe_ftrace(p) do {} while (0) @@ -1141,7 +1152,7 @@ void __kprobes kprobe_flush_task(struct task_struct *tk) { struct kretprobe_instance *ri; struct hlist_head *head, empty_rp; - struct hlist_node *node, *tmp; + struct hlist_node *tmp; unsigned long hash, flags = 0; if (unlikely(!kprobes_initialized)) @@ -1152,12 +1163,12 @@ void __kprobes kprobe_flush_task(struct task_struct *tk) hash = hash_ptr(tk, KPROBE_HASH_BITS); head = &kretprobe_inst_table[hash]; kretprobe_table_lock(hash, &flags); - hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { + hlist_for_each_entry_safe(ri, tmp, head, hlist) { if (ri->task == tk) recycle_rp_inst(ri, &empty_rp); } kretprobe_table_unlock(hash, &flags); - hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { + hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { hlist_del(&ri->hlist); kfree(ri); } @@ -1166,9 +1177,9 @@ void __kprobes kprobe_flush_task(struct task_struct *tk) static inline void free_rp_inst(struct kretprobe *rp) { struct kretprobe_instance *ri; - struct hlist_node *pos, *next; + struct hlist_node *next; - hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) { + hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) { hlist_del(&ri->hlist); kfree(ri); } @@ -1178,14 +1189,14 @@ static void __kprobes cleanup_rp_inst(struct kretprobe *rp) { unsigned long flags, hash; struct kretprobe_instance *ri; - struct hlist_node *pos, *next; + struct hlist_node *next; struct hlist_head *head; /* No race here */ for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { kretprobe_table_lock(hash, &flags); head = &kretprobe_inst_table[hash]; - hlist_for_each_entry_safe(ri, pos, next, head, hlist) { + hlist_for_each_entry_safe(ri, next, head, hlist) { if (ri->rp == rp) ri->rp = NULL; } @@ -1414,12 +1425,12 @@ static __kprobes int check_kprobe_address_safe(struct kprobe *p, */ ftrace_addr = ftrace_location((unsigned long)p->addr); if (ftrace_addr) { -#ifdef KPROBES_CAN_USE_FTRACE +#ifdef CONFIG_KPROBES_ON_FTRACE /* Given address is not on the instruction boundary */ if ((unsigned long)p->addr != ftrace_addr) return -EILSEQ; p->flags |= KPROBE_FLAG_FTRACE; -#else /* !KPROBES_CAN_USE_FTRACE */ +#else /* !CONFIG_KPROBES_ON_FTRACE */ return -EINVAL; #endif } @@ -2021,7 +2032,6 @@ static int __kprobes kprobes_module_callback(struct notifier_block *nb, { struct module *mod = data; struct hlist_head *head; - struct hlist_node *node; struct kprobe *p; unsigned int i; int checkcore = (val == MODULE_STATE_GOING); @@ -2038,7 +2048,7 @@ static int __kprobes kprobes_module_callback(struct notifier_block *nb, mutex_lock(&kprobe_mutex); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; - hlist_for_each_entry_rcu(p, node, head, hlist) + hlist_for_each_entry_rcu(p, head, hlist) if (within_module_init((unsigned long)p->addr, mod) || (checkcore && within_module_core((unsigned long)p->addr, mod))) { @@ -2185,7 +2195,6 @@ static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v) static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) { struct hlist_head *head; - struct hlist_node *node; struct kprobe *p, *kp; const char *sym = NULL; unsigned int i = *(loff_t *) v; @@ -2194,7 +2203,7 @@ static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) head = &kprobe_table[i]; preempt_disable(); - hlist_for_each_entry_rcu(p, node, head, hlist) { + hlist_for_each_entry_rcu(p, head, hlist) { sym = kallsyms_lookup((unsigned long)p->addr, NULL, &offset, &modname, namebuf); if (kprobe_aggrprobe(p)) { @@ -2229,7 +2238,6 @@ static const struct file_operations debugfs_kprobes_operations = { static void __kprobes arm_all_kprobes(void) { struct hlist_head *head; - struct hlist_node *node; struct kprobe *p; unsigned int i; @@ -2242,7 +2250,7 @@ static void __kprobes arm_all_kprobes(void) /* Arming kprobes doesn't optimize kprobe itself */ for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; - hlist_for_each_entry_rcu(p, node, head, hlist) + hlist_for_each_entry_rcu(p, head, hlist) if (!kprobe_disabled(p)) arm_kprobe(p); } @@ -2258,7 +2266,6 @@ already_enabled: static void __kprobes disarm_all_kprobes(void) { struct hlist_head *head; - struct hlist_node *node; struct kprobe *p; unsigned int i; @@ -2275,7 +2282,7 @@ static void __kprobes disarm_all_kprobes(void) for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; - hlist_for_each_entry_rcu(p, node, head, hlist) { + hlist_for_each_entry_rcu(p, head, hlist) { if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) disarm_kprobe(p, false); } diff --git a/kernel/kthread.c b/kernel/kthread.c index 691dc2ef9baf..760e86df8c20 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -17,6 +17,7 @@ #include <linux/slab.h> #include <linux/freezer.h> #include <linux/ptrace.h> +#include <linux/uaccess.h> #include <trace/events/sched.h> static DEFINE_SPINLOCK(kthread_create_lock); @@ -52,8 +53,21 @@ enum KTHREAD_BITS { KTHREAD_IS_PARKED, }; -#define to_kthread(tsk) \ - container_of((tsk)->vfork_done, struct kthread, exited) +#define __to_kthread(vfork) \ + container_of(vfork, struct kthread, exited) + +static inline struct kthread *to_kthread(struct task_struct *k) +{ + return __to_kthread(k->vfork_done); +} + +static struct kthread *to_live_kthread(struct task_struct *k) +{ + struct completion *vfork = ACCESS_ONCE(k->vfork_done); + if (likely(vfork)) + return __to_kthread(vfork); + return NULL; +} /** * kthread_should_stop - should this kthread return now? @@ -122,14 +136,32 @@ void *kthread_data(struct task_struct *task) return to_kthread(task)->data; } +/** + * probe_kthread_data - speculative version of kthread_data() + * @task: possible kthread task in question + * + * @task could be a kthread task. Return the data value specified when it + * was created if accessible. If @task isn't a kthread task or its data is + * inaccessible for any reason, %NULL is returned. This function requires + * that @task itself is safe to dereference. + */ +void *probe_kthread_data(struct task_struct *task) +{ + struct kthread *kthread = to_kthread(task); + void *data = NULL; + + probe_kernel_read(&data, &kthread->data, sizeof(data)); + return data; +} + static void __kthread_parkme(struct kthread *self) { - __set_current_state(TASK_INTERRUPTIBLE); + __set_current_state(TASK_PARKED); while (test_bit(KTHREAD_SHOULD_PARK, &self->flags)) { if (!test_and_set_bit(KTHREAD_IS_PARKED, &self->flags)) complete(&self->parked); schedule(); - __set_current_state(TASK_INTERRUPTIBLE); + __set_current_state(TASK_PARKED); } clear_bit(KTHREAD_IS_PARKED, &self->flags); __set_current_state(TASK_RUNNING); @@ -256,11 +288,16 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), } EXPORT_SYMBOL(kthread_create_on_node); -static void __kthread_bind(struct task_struct *p, unsigned int cpu) +static void __kthread_bind(struct task_struct *p, unsigned int cpu, long state) { + /* Must have done schedule() in kthread() before we set_task_cpu */ + if (!wait_task_inactive(p, state)) { + WARN_ON(1); + return; + } /* It's safe because the task is inactive. */ do_set_cpus_allowed(p, cpumask_of(cpu)); - p->flags |= PF_THREAD_BOUND; + p->flags |= PF_NO_SETAFFINITY; } /** @@ -274,12 +311,7 @@ static void __kthread_bind(struct task_struct *p, unsigned int cpu) */ void kthread_bind(struct task_struct *p, unsigned int cpu) { - /* Must have done schedule() in kthread() before we set_task_cpu */ - if (!wait_task_inactive(p, TASK_UNINTERRUPTIBLE)) { - WARN_ON(1); - return; - } - __kthread_bind(p, cpu); + __kthread_bind(p, cpu, TASK_UNINTERRUPTIBLE); } EXPORT_SYMBOL(kthread_bind); @@ -311,17 +343,20 @@ struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data), return p; } -static struct kthread *task_get_live_kthread(struct task_struct *k) +static void __kthread_unpark(struct task_struct *k, struct kthread *kthread) { - struct kthread *kthread; - - get_task_struct(k); - kthread = to_kthread(k); - /* It might have exited */ - barrier(); - if (k->vfork_done != NULL) - return kthread; - return NULL; + clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags); + /* + * We clear the IS_PARKED bit here as we don't wait + * until the task has left the park code. So if we'd + * park before that happens we'd see the IS_PARKED bit + * which might be about to be cleared. + */ + if (test_and_clear_bit(KTHREAD_IS_PARKED, &kthread->flags)) { + if (test_bit(KTHREAD_IS_PER_CPU, &kthread->flags)) + __kthread_bind(k, kthread->cpu, TASK_PARKED); + wake_up_state(k, TASK_PARKED); + } } /** @@ -334,23 +369,10 @@ static struct kthread *task_get_live_kthread(struct task_struct *k) */ void kthread_unpark(struct task_struct *k) { - struct kthread *kthread = task_get_live_kthread(k); + struct kthread *kthread = to_live_kthread(k); - if (kthread) { - clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags); - /* - * We clear the IS_PARKED bit here as we don't wait - * until the task has left the park code. So if we'd - * park before that happens we'd see the IS_PARKED bit - * which might be about to be cleared. - */ - if (test_and_clear_bit(KTHREAD_IS_PARKED, &kthread->flags)) { - if (test_bit(KTHREAD_IS_PER_CPU, &kthread->flags)) - __kthread_bind(k, kthread->cpu); - wake_up_process(k); - } - } - put_task_struct(k); + if (kthread) + __kthread_unpark(k, kthread); } /** @@ -367,7 +389,7 @@ void kthread_unpark(struct task_struct *k) */ int kthread_park(struct task_struct *k) { - struct kthread *kthread = task_get_live_kthread(k); + struct kthread *kthread = to_live_kthread(k); int ret = -ENOSYS; if (kthread) { @@ -380,7 +402,6 @@ int kthread_park(struct task_struct *k) } ret = 0; } - put_task_struct(k); return ret; } @@ -401,21 +422,23 @@ int kthread_park(struct task_struct *k) */ int kthread_stop(struct task_struct *k) { - struct kthread *kthread = task_get_live_kthread(k); + struct kthread *kthread; int ret; trace_sched_kthread_stop(k); + + get_task_struct(k); + kthread = to_live_kthread(k); if (kthread) { set_bit(KTHREAD_SHOULD_STOP, &kthread->flags); - clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags); + __kthread_unpark(k, kthread); wake_up_process(k); wait_for_completion(&kthread->exited); } ret = k->exit_code; - put_task_struct(k); - trace_sched_kthread_stop_ret(ret); + trace_sched_kthread_stop_ret(ret); return ret; } EXPORT_SYMBOL(kthread_stop); diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 7981e5b2350d..1f3186b37fd5 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -380,6 +380,13 @@ static int verbose(struct lock_class *class) unsigned long nr_stack_trace_entries; static unsigned long stack_trace[MAX_STACK_TRACE_ENTRIES]; +static void print_lockdep_off(const char *bug_msg) +{ + printk(KERN_DEBUG "%s\n", bug_msg); + printk(KERN_DEBUG "turning off the locking correctness validator.\n"); + printk(KERN_DEBUG "Please attach the output of /proc/lock_stat to the bug report\n"); +} + static int save_trace(struct stack_trace *trace) { trace->nr_entries = 0; @@ -409,8 +416,7 @@ static int save_trace(struct stack_trace *trace) if (!debug_locks_off_graph_unlock()) return 0; - printk("BUG: MAX_STACK_TRACE_ENTRIES too low!\n"); - printk("turning off the locking correctness validator.\n"); + print_lockdep_off("BUG: MAX_STACK_TRACE_ENTRIES too low!"); dump_stack(); return 0; @@ -763,8 +769,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force) } raw_local_irq_restore(flags); - printk("BUG: MAX_LOCKDEP_KEYS too low!\n"); - printk("turning off the locking correctness validator.\n"); + print_lockdep_off("BUG: MAX_LOCKDEP_KEYS too low!"); dump_stack(); return NULL; } @@ -834,8 +839,7 @@ static struct lock_list *alloc_list_entry(void) if (!debug_locks_off_graph_unlock()) return NULL; - printk("BUG: MAX_LOCKDEP_ENTRIES too low!\n"); - printk("turning off the locking correctness validator.\n"); + print_lockdep_off("BUG: MAX_LOCKDEP_ENTRIES too low!"); dump_stack(); return NULL; } @@ -2000,7 +2004,7 @@ static inline int lookup_chain_cache(struct task_struct *curr, struct lock_class *class = hlock_class(hlock); struct list_head *hash_head = chainhashentry(chain_key); struct lock_chain *chain; - struct held_lock *hlock_curr, *hlock_next; + struct held_lock *hlock_curr; int i, j; /* @@ -2048,8 +2052,7 @@ cache_hit: if (!debug_locks_off_graph_unlock()) return 0; - printk("BUG: MAX_LOCKDEP_CHAINS too low!\n"); - printk("turning off the locking correctness validator.\n"); + print_lockdep_off("BUG: MAX_LOCKDEP_CHAINS too low!"); dump_stack(); return 0; } @@ -2057,12 +2060,10 @@ cache_hit: chain->chain_key = chain_key; chain->irq_context = hlock->irq_context; /* Find the first held_lock of current chain */ - hlock_next = hlock; for (i = curr->lockdep_depth - 1; i >= 0; i--) { hlock_curr = curr->held_locks + i; - if (hlock_curr->irq_context != hlock_next->irq_context) + if (hlock_curr->irq_context != hlock->irq_context) break; - hlock_next = hlock; } i++; chain->depth = curr->lockdep_depth + 1 - i; @@ -2997,6 +2998,7 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name, EXPORT_SYMBOL_GPL(lockdep_init_map); struct lock_class_key __lockdep_no_validate__; +EXPORT_SYMBOL_GPL(__lockdep_no_validate__); static int print_lock_nested_lock_not_held(struct task_struct *curr, @@ -3190,9 +3192,14 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, #endif if (unlikely(curr->lockdep_depth >= MAX_LOCK_DEPTH)) { debug_locks_off(); - printk("BUG: MAX_LOCK_DEPTH too low!\n"); - printk("turning off the locking correctness validator.\n"); + print_lockdep_off("BUG: MAX_LOCK_DEPTH too low!"); + printk(KERN_DEBUG "depth: %i max: %lu!\n", + curr->lockdep_depth, MAX_LOCK_DEPTH); + + lockdep_print_held_locks(current); + debug_show_all_locks(); dump_stack(); + return 0; } @@ -3203,7 +3210,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, } static int -print_unlock_inbalance_bug(struct task_struct *curr, struct lockdep_map *lock, +print_unlock_imbalance_bug(struct task_struct *curr, struct lockdep_map *lock, unsigned long ip) { if (!debug_locks_off()) @@ -3246,7 +3253,7 @@ static int check_unlock(struct task_struct *curr, struct lockdep_map *lock, return 0; if (curr->lockdep_depth <= 0) - return print_unlock_inbalance_bug(curr, lock, ip); + return print_unlock_imbalance_bug(curr, lock, ip); return 1; } @@ -3317,7 +3324,7 @@ __lock_set_class(struct lockdep_map *lock, const char *name, goto found_it; prev_hlock = hlock; } - return print_unlock_inbalance_bug(curr, lock, ip); + return print_unlock_imbalance_bug(curr, lock, ip); found_it: lockdep_init_map(lock, name, key, 0); @@ -3384,7 +3391,7 @@ lock_release_non_nested(struct task_struct *curr, goto found_it; prev_hlock = hlock; } - return print_unlock_inbalance_bug(curr, lock, ip); + return print_unlock_imbalance_bug(curr, lock, ip); found_it: if (hlock->instance == lock) diff --git a/kernel/modsign_certificate.S b/kernel/modsign_certificate.S index 246b4c6e6135..4a9a86d12c8b 100644 --- a/kernel/modsign_certificate.S +++ b/kernel/modsign_certificate.S @@ -1,15 +1,8 @@ -/* SYMBOL_PREFIX defined on commandline from CONFIG_SYMBOL_PREFIX */ -#ifndef SYMBOL_PREFIX -#define ASM_SYMBOL(sym) sym -#else -#define PASTE2(x,y) x##y -#define PASTE(x,y) PASTE2(x,y) -#define ASM_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym) -#endif +#include <linux/export.h> #define GLOBAL(name) \ - .globl ASM_SYMBOL(name); \ - ASM_SYMBOL(name): + .globl VMLINUX_SYMBOL(name); \ + VMLINUX_SYMBOL(name): .section ".init.data","aw" diff --git a/kernel/module.c b/kernel/module.c index eab08274ec9b..b049939177f6 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -197,9 +197,10 @@ static inline int strong_try_module_get(struct module *mod) return -ENOENT; } -static inline void add_taint_module(struct module *mod, unsigned flag) +static inline void add_taint_module(struct module *mod, unsigned flag, + enum lockdep_ok lockdep_ok) { - add_taint(flag); + add_taint(flag, lockdep_ok); mod->taints |= (1U << flag); } @@ -727,7 +728,7 @@ static inline int try_force_unload(unsigned int flags) { int ret = (flags & O_TRUNC); if (ret) - add_taint(TAINT_FORCED_RMMOD); + add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE); return ret; } #else @@ -1138,7 +1139,7 @@ static int try_to_force_load(struct module *mod, const char *reason) if (!test_taint(TAINT_FORCED_MODULE)) printk(KERN_WARNING "%s: %s: kernel tainted.\n", mod->name, reason); - add_taint_module(mod, TAINT_FORCED_MODULE); + add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE); return 0; #else return -ENOEXEC; @@ -1208,10 +1209,11 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs, /* Since this should be found in kernel (which can't be removed), * no locking is necessary. */ - if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL, + if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL, &crc, true, false)) BUG(); - return check_version(sechdrs, versindex, "module_layout", mod, crc, + return check_version(sechdrs, versindex, + VMLINUX_SYMBOL_STR(module_layout), mod, crc, NULL); } @@ -1860,12 +1862,12 @@ static void free_module(struct module *mod) { trace_module_free(mod); - /* Delete from various lists */ - mutex_lock(&module_mutex); - stop_machine(__unlink_module, mod, NULL); - mutex_unlock(&module_mutex); mod_sysfs_teardown(mod); + /* We leave it in list to prevent duplicate loads, but make sure + * that noone uses it while it's being deconstructed. */ + mod->state = MODULE_STATE_UNFORMED; + /* Remove dynamic debug info */ ddebug_remove_module(mod->name); @@ -1878,6 +1880,11 @@ static void free_module(struct module *mod) /* Free any allocated parameters. */ destroy_params(mod->kp, mod->num_kp); + /* Now we can delete it from the lists */ + mutex_lock(&module_mutex); + stop_machine(__unlink_module, mod, NULL); + mutex_unlock(&module_mutex); + /* This may be NULL, but that's OK */ unset_module_init_ro_nx(mod); module_free(mod, mod->module_init); @@ -2147,7 +2154,8 @@ static void set_license(struct module *mod, const char *license) if (!test_taint(TAINT_PROPRIETARY_MODULE)) printk(KERN_WARNING "%s: module license '%s' taints " "kernel.\n", mod->name, license); - add_taint_module(mod, TAINT_PROPRIETARY_MODULE); + add_taint_module(mod, TAINT_PROPRIETARY_MODULE, + LOCKDEP_NOW_UNRELIABLE); } } @@ -2539,7 +2547,7 @@ static int copy_module_from_fd(int fd, struct load_info *info) if (err) goto out; - err = vfs_getattr(file->f_vfsmnt, file->f_dentry, &stat); + err = vfs_getattr(&file->f_path, &stat); if (err) goto out; @@ -2700,10 +2708,10 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags) } if (!get_modinfo(info, "intree")) - add_taint_module(mod, TAINT_OOT_MODULE); + add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK); if (get_modinfo(info, "staging")) { - add_taint_module(mod, TAINT_CRAP); + add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK); printk(KERN_WARNING "%s: module is from the staging directory," " the quality is unknown, you have been warned.\n", mod->name); @@ -2869,15 +2877,17 @@ static int check_module_license_and_versions(struct module *mod) * using GPL-only symbols it needs. */ if (strcmp(mod->name, "ndiswrapper") == 0) - add_taint(TAINT_PROPRIETARY_MODULE); + add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE); /* driverloader was caught wrongly pretending to be under GPL */ if (strcmp(mod->name, "driverloader") == 0) - add_taint_module(mod, TAINT_PROPRIETARY_MODULE); + add_taint_module(mod, TAINT_PROPRIETARY_MODULE, + LOCKDEP_NOW_UNRELIABLE); /* lve claims to be GPL but upstream won't provide source */ if (strcmp(mod->name, "lve") == 0) - add_taint_module(mod, TAINT_PROPRIETARY_MODULE); + add_taint_module(mod, TAINT_PROPRIETARY_MODULE, + LOCKDEP_NOW_UNRELIABLE); #ifdef CONFIG_MODVERSIONS if ((mod->num_syms && !mod->crcs) @@ -3141,12 +3151,72 @@ static int may_init_module(void) return 0; } +/* + * We try to place it in the list now to make sure it's unique before + * we dedicate too many resources. In particular, temporary percpu + * memory exhaustion. + */ +static int add_unformed_module(struct module *mod) +{ + int err; + struct module *old; + + mod->state = MODULE_STATE_UNFORMED; + +again: + mutex_lock(&module_mutex); + if ((old = find_module_all(mod->name, true)) != NULL) { + if (old->state == MODULE_STATE_COMING + || old->state == MODULE_STATE_UNFORMED) { + /* Wait in case it fails to load. */ + mutex_unlock(&module_mutex); + err = wait_event_interruptible(module_wq, + finished_loading(mod->name)); + if (err) + goto out_unlocked; + goto again; + } + err = -EEXIST; + goto out; + } + list_add_rcu(&mod->list, &modules); + err = 0; + +out: + mutex_unlock(&module_mutex); +out_unlocked: + return err; +} + +static int complete_formation(struct module *mod, struct load_info *info) +{ + int err; + + mutex_lock(&module_mutex); + + /* Find duplicate symbols (must be called under lock). */ + err = verify_export_symbols(mod); + if (err < 0) + goto out; + + /* This relies on module_mutex for list integrity. */ + module_bug_finalize(info->hdr, info->sechdrs, mod); + + /* Mark state as coming so strong_try_module_get() ignores us, + * but kallsyms etc. can see us. */ + mod->state = MODULE_STATE_COMING; + +out: + mutex_unlock(&module_mutex); + return err; +} + /* Allocate and load the module: note that size of section 0 is always zero, and we rely on this for optional sections. */ static int load_module(struct load_info *info, const char __user *uargs, int flags) { - struct module *mod, *old; + struct module *mod; long err; err = module_sig_check(info); @@ -3164,36 +3234,20 @@ static int load_module(struct load_info *info, const char __user *uargs, goto free_copy; } - /* - * We try to place it in the list now to make sure it's unique - * before we dedicate too many resources. In particular, - * temporary percpu memory exhaustion. - */ - mod->state = MODULE_STATE_UNFORMED; -again: - mutex_lock(&module_mutex); - if ((old = find_module_all(mod->name, true)) != NULL) { - if (old->state == MODULE_STATE_COMING - || old->state == MODULE_STATE_UNFORMED) { - /* Wait in case it fails to load. */ - mutex_unlock(&module_mutex); - err = wait_event_interruptible(module_wq, - finished_loading(mod->name)); - if (err) - goto free_module; - goto again; - } - err = -EEXIST; - mutex_unlock(&module_mutex); + /* Reserve our place in the list. */ + err = add_unformed_module(mod); + if (err) goto free_module; - } - list_add_rcu(&mod->list, &modules); - mutex_unlock(&module_mutex); #ifdef CONFIG_MODULE_SIG mod->sig_ok = info->sig_ok; - if (!mod->sig_ok) - add_taint_module(mod, TAINT_FORCED_MODULE); + if (!mod->sig_ok) { + printk_once(KERN_NOTICE + "%s: module verification failed: signature and/or" + " required key missing - tainting kernel\n", + mod->name); + add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_STILL_OK); + } #endif /* Now module is in final location, initialize linked lists, etc. */ @@ -3236,21 +3290,11 @@ again: dynamic_debug_setup(info->debug, info->num_debug); - mutex_lock(&module_mutex); - /* Find duplicate symbols (must be called under lock). */ - err = verify_export_symbols(mod); - if (err < 0) + /* Finally it's fully formed, ready to start executing. */ + err = complete_formation(mod, info); + if (err) goto ddebug_cleanup; - /* This relies on module_mutex for list integrity. */ - module_bug_finalize(info->hdr, info->sechdrs, mod); - - /* Mark state as coming so strong_try_module_get() ignores us, - * but kallsyms etc. can see us. */ - mod->state = MODULE_STATE_COMING; - - mutex_unlock(&module_mutex); - /* Module is ready to execute: parsing args may do that. */ err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, -32768, 32767, &ddebug_dyndbg_module_param_cb); @@ -3274,8 +3318,8 @@ again: /* module_bug_cleanup needs module_mutex protection */ mutex_lock(&module_mutex); module_bug_cleanup(mod); - ddebug_cleanup: mutex_unlock(&module_mutex); + ddebug_cleanup: dynamic_debug_remove(info->debug); synchronize_sched(); kfree(mod->args); diff --git a/kernel/mutex.c b/kernel/mutex.c index a307cc9c9526..ad53a664f113 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -19,6 +19,7 @@ */ #include <linux/mutex.h> #include <linux/sched.h> +#include <linux/sched/rt.h> #include <linux/export.h> #include <linux/spinlock.h> #include <linux/interrupt.h> @@ -36,6 +37,12 @@ # include <asm/mutex.h> #endif +/* + * A negative mutex count indicates that waiters are sleeping waiting for the + * mutex. + */ +#define MUTEX_SHOW_NO_WAITER(mutex) (atomic_read(&(mutex)->count) >= 0) + void __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key) { @@ -43,6 +50,9 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key) spin_lock_init(&lock->wait_lock); INIT_LIST_HEAD(&lock->wait_list); mutex_clear_owner(lock); +#ifdef CONFIG_MUTEX_SPIN_ON_OWNER + lock->spin_mlock = NULL; +#endif debug_mutex_init(lock, name, key); } @@ -94,6 +104,124 @@ void __sched mutex_lock(struct mutex *lock) EXPORT_SYMBOL(mutex_lock); #endif +#ifdef CONFIG_MUTEX_SPIN_ON_OWNER +/* + * In order to avoid a stampede of mutex spinners from acquiring the mutex + * more or less simultaneously, the spinners need to acquire a MCS lock + * first before spinning on the owner field. + * + * We don't inline mspin_lock() so that perf can correctly account for the + * time spent in this lock function. + */ +struct mspin_node { + struct mspin_node *next ; + int locked; /* 1 if lock acquired */ +}; +#define MLOCK(mutex) ((struct mspin_node **)&((mutex)->spin_mlock)) + +static noinline +void mspin_lock(struct mspin_node **lock, struct mspin_node *node) +{ + struct mspin_node *prev; + + /* Init node */ + node->locked = 0; + node->next = NULL; + + prev = xchg(lock, node); + if (likely(prev == NULL)) { + /* Lock acquired */ + node->locked = 1; + return; + } + ACCESS_ONCE(prev->next) = node; + smp_wmb(); + /* Wait until the lock holder passes the lock down */ + while (!ACCESS_ONCE(node->locked)) + arch_mutex_cpu_relax(); +} + +static void mspin_unlock(struct mspin_node **lock, struct mspin_node *node) +{ + struct mspin_node *next = ACCESS_ONCE(node->next); + + if (likely(!next)) { + /* + * Release the lock by setting it to NULL + */ + if (cmpxchg(lock, node, NULL) == node) + return; + /* Wait until the next pointer is set */ + while (!(next = ACCESS_ONCE(node->next))) + arch_mutex_cpu_relax(); + } + ACCESS_ONCE(next->locked) = 1; + smp_wmb(); +} + +/* + * Mutex spinning code migrated from kernel/sched/core.c + */ + +static inline bool owner_running(struct mutex *lock, struct task_struct *owner) +{ + if (lock->owner != owner) + return false; + + /* + * Ensure we emit the owner->on_cpu, dereference _after_ checking + * lock->owner still matches owner, if that fails, owner might + * point to free()d memory, if it still matches, the rcu_read_lock() + * ensures the memory stays valid. + */ + barrier(); + + return owner->on_cpu; +} + +/* + * Look out! "owner" is an entirely speculative pointer + * access and not reliable. + */ +static noinline +int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner) +{ + rcu_read_lock(); + while (owner_running(lock, owner)) { + if (need_resched()) + break; + + arch_mutex_cpu_relax(); + } + rcu_read_unlock(); + + /* + * We break out the loop above on need_resched() and when the + * owner changed, which is a sign for heavy contention. Return + * success only when lock->owner is NULL. + */ + return lock->owner == NULL; +} + +/* + * Initial check for entering the mutex spinning loop + */ +static inline int mutex_can_spin_on_owner(struct mutex *lock) +{ + int retval = 1; + + rcu_read_lock(); + if (lock->owner) + retval = lock->owner->on_cpu; + rcu_read_unlock(); + /* + * if lock->owner is not set, the mutex owner may have just acquired + * it and not set the owner yet or the mutex has been released. + */ + return retval; +} +#endif + static __used noinline void __sched __mutex_unlock_slowpath(atomic_t *lock_count); /** @@ -157,25 +285,39 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, * * We can't do this for DEBUG_MUTEXES because that relies on wait_lock * to serialize everything. + * + * The mutex spinners are queued up using MCS lock so that only one + * spinner can compete for the mutex. However, if mutex spinning isn't + * going to happen, there is no point in going through the lock/unlock + * overhead. */ + if (!mutex_can_spin_on_owner(lock)) + goto slowpath; for (;;) { struct task_struct *owner; + struct mspin_node node; /* * If there's an owner, wait for it to either * release the lock or go to sleep. */ + mspin_lock(MLOCK(lock), &node); owner = ACCESS_ONCE(lock->owner); - if (owner && !mutex_spin_on_owner(lock, owner)) + if (owner && !mutex_spin_on_owner(lock, owner)) { + mspin_unlock(MLOCK(lock), &node); break; + } - if (atomic_cmpxchg(&lock->count, 1, 0) == 1) { + if ((atomic_read(&lock->count) == 1) && + (atomic_cmpxchg(&lock->count, 1, 0) == 1)) { lock_acquired(&lock->dep_map, ip); mutex_set_owner(lock); + mspin_unlock(MLOCK(lock), &node); preempt_enable(); return 0; } + mspin_unlock(MLOCK(lock), &node); /* * When there's no owner, we might have preempted between the @@ -194,6 +336,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, */ arch_mutex_cpu_relax(); } +slowpath: #endif spin_lock_mutex(&lock->wait_lock, flags); @@ -204,7 +347,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, list_add_tail(&waiter.list, &lock->wait_list); waiter.task = task; - if (atomic_xchg(&lock->count, -1) == 1) + if (MUTEX_SHOW_NO_WAITER(lock) && (atomic_xchg(&lock->count, -1) == 1)) goto done; lock_contended(&lock->dep_map, ip); @@ -219,7 +362,8 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, * that when we release the lock, we properly wake up the * other waiters: */ - if (atomic_xchg(&lock->count, -1) == 1) + if (MUTEX_SHOW_NO_WAITER(lock) && + (atomic_xchg(&lock->count, -1) == 1)) break; /* diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index 78e2ecb20165..364ceab15f0c 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -22,7 +22,7 @@ #include <linux/pid_namespace.h> #include <net/net_namespace.h> #include <linux/ipc_namespace.h> -#include <linux/proc_fs.h> +#include <linux/proc_ns.h> #include <linux/file.h> #include <linux/syscalls.h> @@ -153,8 +153,7 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk) goto out; } - new_ns = create_new_namespaces(flags, tsk, - task_cred_xxx(tsk, user_ns), tsk->fs); + new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs); if (IS_ERR(new_ns)) { err = PTR_ERR(new_ns); goto out; @@ -242,7 +241,7 @@ SYSCALL_DEFINE2(setns, int, fd, int, nstype) const struct proc_ns_operations *ops; struct task_struct *tsk = current; struct nsproxy *new_nsproxy; - struct proc_inode *ei; + struct proc_ns *ei; struct file *file; int err; @@ -251,7 +250,7 @@ SYSCALL_DEFINE2(setns, int, fd, int, nstype) return PTR_ERR(file); err = -EINVAL; - ei = PROC_I(file->f_dentry->d_inode); + ei = get_proc_ns(file_inode(file)); ops = ei->ns_ops; if (nstype && (ops->type != nstype)) goto out; diff --git a/kernel/panic.c b/kernel/panic.c index e1b2822fff97..167ec097ce8b 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -22,7 +22,6 @@ #include <linux/sysrq.h> #include <linux/init.h> #include <linux/nmi.h> -#include <linux/dmi.h> #define PANIC_TIMER_STEP 100 #define PANIC_BLINK_SPD 18 @@ -259,26 +258,19 @@ unsigned long get_taint(void) return tainted_mask; } -void add_taint(unsigned flag) +/** + * add_taint: add a taint flag if not already set. + * @flag: one of the TAINT_* constants. + * @lockdep_ok: whether lock debugging is still OK. + * + * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for + * some notewortht-but-not-corrupting cases, it can be set to true. + */ +void add_taint(unsigned flag, enum lockdep_ok lockdep_ok) { - /* - * Can't trust the integrity of the kernel anymore. - * We don't call directly debug_locks_off() because the issue - * is not necessarily serious enough to set oops_in_progress to 1 - * Also we want to keep up lockdep for staging/out-of-tree - * development and post-warning case. - */ - switch (flag) { - case TAINT_CRAP: - case TAINT_OOT_MODULE: - case TAINT_WARN: - case TAINT_FIRMWARE_WORKAROUND: - break; - - default: - if (__debug_locks_off()) - printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n"); - } + if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off()) + printk(KERN_WARNING + "Disabling lock debugging due to kernel taint\n"); set_bit(flag, &tainted_mask); } @@ -407,13 +399,8 @@ struct slowpath_args { static void warn_slowpath_common(const char *file, int line, void *caller, unsigned taint, struct slowpath_args *args) { - const char *board; - printk(KERN_WARNING "------------[ cut here ]------------\n"); printk(KERN_WARNING "WARNING: at %s:%d %pS()\n", file, line, caller); - board = dmi_get_system_info(DMI_PRODUCT_NAME); - if (board) - printk(KERN_WARNING "Hardware name: %s\n", board); if (args) vprintk(args->fmt, args->args); @@ -421,7 +408,8 @@ static void warn_slowpath_common(const char *file, int line, void *caller, print_modules(); dump_stack(); print_oops_end_marker(); - add_taint(taint); + /* Just a warning, don't kill lockdep. */ + add_taint(taint, LOCKDEP_STILL_OK); } void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...) diff --git a/kernel/params.c b/kernel/params.c index ed35345be536..53b958fcd639 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -613,10 +613,13 @@ static __modinit int add_sysfs_param(struct module_kobject *mk, sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1), GFP_KERNEL); if (!new) { - kfree(mk->mp); + kfree(attrs); err = -ENOMEM; goto fail; } + /* Despite looking like the typical realloc() bug, this is safe. + * We *want* the old 'attrs' to be freed either way, and we'll store + * the new one in the success case. */ attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL); if (!attrs) { err = -ENOMEM; diff --git a/kernel/pid.c b/kernel/pid.c index f2c6a6825098..0db3e791a06d 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -36,6 +36,7 @@ #include <linux/pid_namespace.h> #include <linux/init_task.h> #include <linux/syscalls.h> +#include <linux/proc_ns.h> #include <linux/proc_fs.h> #define pid_hashfn(nr, ns) \ @@ -51,9 +52,6 @@ int pid_max = PID_MAX_DEFAULT; int pid_max_min = RESERVED_PIDS + 1; int pid_max_max = PID_MAX_LIMIT; -#define BITS_PER_PAGE (PAGE_SIZE*8) -#define BITS_PER_PAGE_MASK (BITS_PER_PAGE-1) - static inline int mk_pid(struct pid_namespace *pid_ns, struct pidmap *map, int off) { @@ -183,15 +181,19 @@ static int alloc_pidmap(struct pid_namespace *pid_ns) break; } if (likely(atomic_read(&map->nr_free))) { - do { + for ( ; ; ) { if (!test_and_set_bit(offset, map->page)) { atomic_dec(&map->nr_free); set_last_pid(pid_ns, last, pid); return pid; } offset = find_next_offset(map, offset); + if (offset >= BITS_PER_PAGE) + break; pid = mk_pid(pid_ns, map, offset); - } while (offset < BITS_PER_PAGE && pid < pid_max); + if (pid >= pid_max) + break; + } } if (map < &pid_ns->pidmap[(pid_max-1)/BITS_PER_PAGE]) { ++map; @@ -350,10 +352,9 @@ void disable_pid_allocation(struct pid_namespace *ns) struct pid *find_pid_ns(int nr, struct pid_namespace *ns) { - struct hlist_node *elem; struct upid *pnr; - hlist_for_each_entry_rcu(pnr, elem, + hlist_for_each_entry_rcu(pnr, &pid_hash[pid_hashfn(nr, ns)], pid_chain) if (pnr->nr == nr && pnr->ns == ns) return container_of(pnr, struct pid, diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index c1c3dc1c6023..6917e8edb48e 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -15,12 +15,10 @@ #include <linux/err.h> #include <linux/acct.h> #include <linux/slab.h> -#include <linux/proc_fs.h> +#include <linux/proc_ns.h> #include <linux/reboot.h> #include <linux/export.h> -#define BITS_PER_PAGE (PAGE_SIZE*8) - struct pid_cache { int nr_ids; char name[16]; @@ -181,6 +179,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) int nr; int rc; struct task_struct *task, *me = current; + int init_pids = thread_group_leader(me) ? 1 : 2; /* Don't allow any more processes into the pid namespace */ disable_pid_allocation(pid_ns); @@ -230,7 +229,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) */ for (;;) { set_current_state(TASK_UNINTERRUPTIBLE); - if (pid_ns->nr_hashed == 1) + if (pid_ns->nr_hashed == init_pids) break; schedule(); } diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index a278cad1d5d6..42670e9b44e0 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -10,6 +10,8 @@ #include <linux/kernel_stat.h> #include <trace/events/timer.h> #include <linux/random.h> +#include <linux/tick.h> +#include <linux/workqueue.h> /* * Called after updating RLIMIT_CPU to run cpu timer and update @@ -153,13 +155,36 @@ static void bump_cpu_timer(struct k_itimer *timer, } } +/** + * task_cputime_zero - Check a task_cputime struct for all zero fields. + * + * @cputime: The struct to compare. + * + * Checks @cputime to see if all fields are zero. Returns true if all fields + * are zero, false if any field is nonzero. + */ +static inline int task_cputime_zero(const struct task_cputime *cputime) +{ + if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime) + return 1; + return 0; +} + static inline cputime_t prof_ticks(struct task_struct *p) { - return p->utime + p->stime; + cputime_t utime, stime; + + task_cputime(p, &utime, &stime); + + return utime + stime; } static inline cputime_t virt_ticks(struct task_struct *p) { - return p->utime; + cputime_t utime; + + task_cputime(p, &utime, NULL); + + return utime; } static int @@ -471,18 +496,23 @@ static void cleanup_timers(struct list_head *head, */ void posix_cpu_timers_exit(struct task_struct *tsk) { + cputime_t utime, stime; + add_device_randomness((const void*) &tsk->se.sum_exec_runtime, sizeof(unsigned long long)); + task_cputime(tsk, &utime, &stime); cleanup_timers(tsk->cpu_timers, - tsk->utime, tsk->stime, tsk->se.sum_exec_runtime); + utime, stime, tsk->se.sum_exec_runtime); } void posix_cpu_timers_exit_group(struct task_struct *tsk) { struct signal_struct *const sig = tsk->signal; + cputime_t utime, stime; + task_cputime(tsk, &utime, &stime); cleanup_timers(tsk->signal->cpu_timers, - tsk->utime + sig->utime, tsk->stime + sig->stime, + utime + sig->utime, stime + sig->stime, tsk->se.sum_exec_runtime + sig->sum_sched_runtime); } @@ -623,6 +653,37 @@ static int cpu_timer_sample_group(const clockid_t which_clock, return 0; } +#ifdef CONFIG_NO_HZ_FULL +static void nohz_kick_work_fn(struct work_struct *work) +{ + tick_nohz_full_kick_all(); +} + +static DECLARE_WORK(nohz_kick_work, nohz_kick_work_fn); + +/* + * We need the IPIs to be sent from sane process context. + * The posix cpu timers are always set with irqs disabled. + */ +static void posix_cpu_timer_kick_nohz(void) +{ + schedule_work(&nohz_kick_work); +} + +bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk) +{ + if (!task_cputime_zero(&tsk->cputime_expires)) + return false; + + if (tsk->signal->cputimer.running) + return false; + + return true; +} +#else +static inline void posix_cpu_timer_kick_nohz(void) { } +#endif + /* * Guts of sys_timer_settime for CPU timers. * This is called with the timer locked and interrupts disabled. @@ -781,6 +842,8 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int flags, sample_to_timespec(timer->it_clock, old_incr, &old->it_interval); } + if (!ret) + posix_cpu_timer_kick_nohz(); return ret; } @@ -995,21 +1058,6 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, } } -/** - * task_cputime_zero - Check a task_cputime struct for all zero fields. - * - * @cputime: The struct to compare. - * - * Checks @cputime to see if all fields are zero. Returns true if all fields - * are zero, false if any field is nonzero. - */ -static inline int task_cputime_zero(const struct task_cputime *cputime) -{ - if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime) - return 1; - return 0; -} - /* * Check for any per-thread CPU timers that have fired and move them * off the tsk->*_timers list onto the firing list. Per-thread timers @@ -1226,11 +1274,14 @@ static inline int task_cputime_expired(const struct task_cputime *sample, static inline int fastpath_timer_check(struct task_struct *tsk) { struct signal_struct *sig; + cputime_t utime, stime; + + task_cputime(tsk, &utime, &stime); if (!task_cputime_zero(&tsk->cputime_expires)) { struct task_cputime task_sample = { - .utime = tsk->utime, - .stime = tsk->stime, + .utime = utime, + .stime = stime, .sum_exec_runtime = tsk->se.sum_exec_runtime }; @@ -1320,6 +1371,13 @@ void run_posix_cpu_timers(struct task_struct *tsk) cpu_timer_fire(timer); spin_unlock(&timer->it_lock); } + + /* + * In case some timers were rescheduled after the queue got emptied, + * wake up full dynticks CPUs. + */ + if (tsk->signal->cputimer.running) + posix_cpu_timer_kick_nohz(); } /* @@ -1350,7 +1408,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, } if (!*newval) - return; + goto out; *newval += now.cpu; } @@ -1368,6 +1426,8 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, tsk->signal->cputime_expires.virt_exp = *newval; break; } +out: + posix_cpu_timer_kick_nohz(); } static int do_cpu_nanosleep(const clockid_t which_clock, int flags, @@ -1401,8 +1461,10 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags, while (!signal_pending(current)) { if (timer.it.cpu.expires.sched == 0) { /* - * Our timer fired and was reset. + * Our timer fired and was reset, below + * deletion can not fail. */ + posix_cpu_timer_del(&timer); spin_unlock_irq(&timer.it_lock); return 0; } @@ -1420,9 +1482,26 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags, * We were interrupted by a signal. */ sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp); - posix_cpu_timer_set(&timer, 0, &zero_it, it); + error = posix_cpu_timer_set(&timer, 0, &zero_it, it); + if (!error) { + /* + * Timer is now unarmed, deletion can not fail. + */ + posix_cpu_timer_del(&timer); + } spin_unlock_irq(&timer.it_lock); + while (error == TIMER_RETRY) { + /* + * We need to handle case when timer was or is in the + * middle of firing. In other cases we already freed + * resources. + */ + spin_lock_irq(&timer.it_lock); + error = posix_cpu_timer_del(&timer); + spin_unlock_irq(&timer.it_lock); + } + if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) { /* * It actually did fire already. diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 69185ae6b701..424c2d4265c9 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -40,38 +40,31 @@ #include <linux/list.h> #include <linux/init.h> #include <linux/compiler.h> -#include <linux/idr.h> +#include <linux/hash.h> #include <linux/posix-clock.h> #include <linux/posix-timers.h> #include <linux/syscalls.h> #include <linux/wait.h> #include <linux/workqueue.h> #include <linux/export.h> +#include <linux/hashtable.h> /* - * Management arrays for POSIX timers. Timers are kept in slab memory - * Timer ids are allocated by an external routine that keeps track of the - * id and the timer. The external interface is: - * - * void *idr_find(struct idr *idp, int id); to find timer_id <id> - * int idr_get_new(struct idr *idp, void *ptr); to get a new id and - * related it to <ptr> - * void idr_remove(struct idr *idp, int id); to release <id> - * void idr_init(struct idr *idp); to initialize <idp> - * which we supply. - * The idr_get_new *may* call slab for more memory so it must not be - * called under a spin lock. Likewise idr_remore may release memory - * (but it may be ok to do this under a lock...). - * idr_find is just a memory look up and is quite fast. A -1 return - * indicates that the requested id does not exist. + * Management arrays for POSIX timers. Timers are now kept in static hash table + * with 512 entries. + * Timer ids are allocated by local routine, which selects proper hash head by + * key, constructed from current->signal address and per signal struct counter. + * This keeps timer ids unique per process, but now they can intersect between + * processes. */ /* * Lets keep our timers in a slab cache :-) */ static struct kmem_cache *posix_timers_cache; -static struct idr posix_timers_id; -static DEFINE_SPINLOCK(idr_lock); + +static DEFINE_HASHTABLE(posix_timers_hashtable, 9); +static DEFINE_SPINLOCK(hash_lock); /* * we assume that the new SIGEV_THREAD_ID shares no bits with the other @@ -152,6 +145,56 @@ static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags); __timr; \ }) +static int hash(struct signal_struct *sig, unsigned int nr) +{ + return hash_32(hash32_ptr(sig) ^ nr, HASH_BITS(posix_timers_hashtable)); +} + +static struct k_itimer *__posix_timers_find(struct hlist_head *head, + struct signal_struct *sig, + timer_t id) +{ + struct k_itimer *timer; + + hlist_for_each_entry_rcu(timer, head, t_hash) { + if ((timer->it_signal == sig) && (timer->it_id == id)) + return timer; + } + return NULL; +} + +static struct k_itimer *posix_timer_by_id(timer_t id) +{ + struct signal_struct *sig = current->signal; + struct hlist_head *head = &posix_timers_hashtable[hash(sig, id)]; + + return __posix_timers_find(head, sig, id); +} + +static int posix_timer_add(struct k_itimer *timer) +{ + struct signal_struct *sig = current->signal; + int first_free_id = sig->posix_timer_id; + struct hlist_head *head; + int ret = -ENOENT; + + do { + spin_lock(&hash_lock); + head = &posix_timers_hashtable[hash(sig, sig->posix_timer_id)]; + if (!__posix_timers_find(head, sig, sig->posix_timer_id)) { + hlist_add_head_rcu(&timer->t_hash, head); + ret = sig->posix_timer_id; + } + if (++sig->posix_timer_id < 0) + sig->posix_timer_id = 0; + if ((sig->posix_timer_id == first_free_id) && (ret == -ENOENT)) + /* Loop over all possible ids completed */ + ret = -EAGAIN; + spin_unlock(&hash_lock); + } while (ret == -ENOENT); + return ret; +} + static inline void unlock_timer(struct k_itimer *timr, unsigned long flags) { spin_unlock_irqrestore(&timr->it_lock, flags); @@ -221,6 +264,11 @@ static int posix_get_boottime(const clockid_t which_clock, struct timespec *tp) return 0; } +static int posix_get_tai(clockid_t which_clock, struct timespec *tp) +{ + timekeeping_clocktai(tp); + return 0; +} /* * Initialize everything, well, just everything in Posix clocks/timers ;) @@ -261,6 +309,16 @@ static __init int init_posix_timers(void) .clock_getres = posix_get_coarse_res, .clock_get = posix_get_monotonic_coarse, }; + struct k_clock clock_tai = { + .clock_getres = hrtimer_get_res, + .clock_get = posix_get_tai, + .nsleep = common_nsleep, + .nsleep_restart = hrtimer_nanosleep_restart, + .timer_create = common_timer_create, + .timer_set = common_timer_set, + .timer_get = common_timer_get, + .timer_del = common_timer_del, + }; struct k_clock clock_boottime = { .clock_getres = hrtimer_get_res, .clock_get = posix_get_boottime, @@ -278,11 +336,11 @@ static __init int init_posix_timers(void) posix_timers_register_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse); posix_timers_register_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse); posix_timers_register_clock(CLOCK_BOOTTIME, &clock_boottime); + posix_timers_register_clock(CLOCK_TAI, &clock_tai); posix_timers_cache = kmem_cache_create("posix_timers_cache", sizeof (struct k_itimer), 0, SLAB_PANIC, NULL); - idr_init(&posix_timers_id); return 0; } @@ -504,9 +562,9 @@ static void release_posix_timer(struct k_itimer *tmr, int it_id_set) { if (it_id_set) { unsigned long flags; - spin_lock_irqsave(&idr_lock, flags); - idr_remove(&posix_timers_id, tmr->it_id); - spin_unlock_irqrestore(&idr_lock, flags); + spin_lock_irqsave(&hash_lock, flags); + hlist_del_rcu(&tmr->t_hash); + spin_unlock_irqrestore(&hash_lock, flags); } put_pid(tmr->it_pid); sigqueue_free(tmr->sigq); @@ -552,22 +610,9 @@ SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock, return -EAGAIN; spin_lock_init(&new_timer->it_lock); - retry: - if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) { - error = -EAGAIN; - goto out; - } - spin_lock_irq(&idr_lock); - error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id); - spin_unlock_irq(&idr_lock); - if (error) { - if (error == -EAGAIN) - goto retry; - /* - * Weird looking, but we return EAGAIN if the IDR is - * full (proper POSIX return value for this) - */ - error = -EAGAIN; + new_timer_id = posix_timer_add(new_timer); + if (new_timer_id < 0) { + error = new_timer_id; goto out; } @@ -639,8 +684,15 @@ static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags) { struct k_itimer *timr; + /* + * timer_t could be any type >= int and we want to make sure any + * @timer_id outside positive int range fails lookup. + */ + if ((unsigned long long)timer_id > INT_MAX) + return NULL; + rcu_read_lock(); - timr = idr_find(&posix_timers_id, (int)timer_id); + timr = posix_timer_by_id(timer_id); if (timr) { spin_lock_irqsave(&timr->it_lock, *flags); if (timr->it_signal == current->signal) { @@ -997,7 +1049,7 @@ SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock, err = kc->clock_adj(which_clock, &ktx); - if (!err && copy_to_user(utx, &ktx, sizeof(ktx))) + if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx))) return -EFAULT; return err; diff --git a/kernel/power/autosleep.c b/kernel/power/autosleep.c index ca304046d9e2..c6422ffeda9a 100644 --- a/kernel/power/autosleep.c +++ b/kernel/power/autosleep.c @@ -66,7 +66,7 @@ static DECLARE_WORK(suspend_work, try_to_suspend); void queue_up_suspend_work(void) { - if (!work_pending(&suspend_work) && autosleep_state > PM_SUSPEND_ON) + if (autosleep_state > PM_SUSPEND_ON) queue_work(autosleep_wq, &suspend_work); } diff --git a/kernel/power/console.c b/kernel/power/console.c index b1dc456474b5..463aa6736751 100644 --- a/kernel/power/console.c +++ b/kernel/power/console.c @@ -4,6 +4,7 @@ * Originally from swsusp. */ +#include <linux/console.h> #include <linux/vt_kern.h> #include <linux/kbd_kern.h> #include <linux/vt.h> @@ -14,8 +15,120 @@ static int orig_fgconsole, orig_kmsg; +static DEFINE_MUTEX(vt_switch_mutex); + +struct pm_vt_switch { + struct list_head head; + struct device *dev; + bool required; +}; + +static LIST_HEAD(pm_vt_switch_list); + + +/** + * pm_vt_switch_required - indicate VT switch at suspend requirements + * @dev: device + * @required: if true, caller needs VT switch at suspend/resume time + * + * The different console drivers may or may not require VT switches across + * suspend/resume, depending on how they handle restoring video state and + * what may be running. + * + * Drivers can indicate support for switchless suspend/resume, which can + * save time and flicker, by using this routine and passing 'false' as + * the argument. If any loaded driver needs VT switching, or the + * no_console_suspend argument has been passed on the command line, VT + * switches will occur. + */ +void pm_vt_switch_required(struct device *dev, bool required) +{ + struct pm_vt_switch *entry, *tmp; + + mutex_lock(&vt_switch_mutex); + list_for_each_entry(tmp, &pm_vt_switch_list, head) { + if (tmp->dev == dev) { + /* already registered, update requirement */ + tmp->required = required; + goto out; + } + } + + entry = kmalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + goto out; + + entry->required = required; + entry->dev = dev; + + list_add(&entry->head, &pm_vt_switch_list); +out: + mutex_unlock(&vt_switch_mutex); +} +EXPORT_SYMBOL(pm_vt_switch_required); + +/** + * pm_vt_switch_unregister - stop tracking a device's VT switching needs + * @dev: device + * + * Remove @dev from the vt switch list. + */ +void pm_vt_switch_unregister(struct device *dev) +{ + struct pm_vt_switch *tmp; + + mutex_lock(&vt_switch_mutex); + list_for_each_entry(tmp, &pm_vt_switch_list, head) { + if (tmp->dev == dev) { + list_del(&tmp->head); + break; + } + } + mutex_unlock(&vt_switch_mutex); +} +EXPORT_SYMBOL(pm_vt_switch_unregister); + +/* + * There are three cases when a VT switch on suspend/resume are required: + * 1) no driver has indicated a requirement one way or another, so preserve + * the old behavior + * 2) console suspend is disabled, we want to see debug messages across + * suspend/resume + * 3) any registered driver indicates it needs a VT switch + * + * If none of these conditions is present, meaning we have at least one driver + * that doesn't need the switch, and none that do, we can avoid it to make + * resume look a little prettier (and suspend too, but that's usually hidden, + * e.g. when closing the lid on a laptop). + */ +static bool pm_vt_switch(void) +{ + struct pm_vt_switch *entry; + bool ret = true; + + mutex_lock(&vt_switch_mutex); + if (list_empty(&pm_vt_switch_list)) + goto out; + + if (!console_suspend_enabled) + goto out; + + list_for_each_entry(entry, &pm_vt_switch_list, head) { + if (entry->required) + goto out; + } + + ret = false; +out: + mutex_unlock(&vt_switch_mutex); + return ret; +} + int pm_prepare_console(void) { + if (!pm_vt_switch()) + return 0; + orig_fgconsole = vt_move_to_console(SUSPEND_CONSOLE, 1); if (orig_fgconsole < 0) return 1; @@ -26,6 +139,9 @@ int pm_prepare_console(void) void pm_restore_console(void) { + if (!pm_vt_switch()) + return; + if (orig_fgconsole >= 0) { vt_move_to_console(orig_fgconsole, 0); vt_kmsg_redirect(orig_kmsg); diff --git a/kernel/power/main.c b/kernel/power/main.c index 1c16f9167de1..d77663bfedeb 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -313,7 +313,7 @@ static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr, static suspend_state_t decode_state(const char *buf, size_t n) { #ifdef CONFIG_SUSPEND - suspend_state_t state = PM_SUSPEND_STANDBY; + suspend_state_t state = PM_SUSPEND_MIN; const char * const *s; #endif char *p; @@ -553,6 +553,30 @@ power_attr(pm_trace_dev_match); #endif /* CONFIG_PM_TRACE */ +#ifdef CONFIG_FREEZER +static ssize_t pm_freeze_timeout_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%u\n", freeze_timeout_msecs); +} + +static ssize_t pm_freeze_timeout_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t n) +{ + unsigned long val; + + if (kstrtoul(buf, 10, &val)) + return -EINVAL; + + freeze_timeout_msecs = val; + return n; +} + +power_attr(pm_freeze_timeout); + +#endif /* CONFIG_FREEZER*/ + static struct attribute * g[] = { &state_attr.attr, #ifdef CONFIG_PM_TRACE @@ -576,6 +600,9 @@ static struct attribute * g[] = { &pm_print_times_attr.attr, #endif #endif +#ifdef CONFIG_FREEZER + &pm_freeze_timeout_attr.attr, +#endif NULL, }; diff --git a/kernel/power/poweroff.c b/kernel/power/poweroff.c index 68197a4e8fc9..7ef6866b521d 100644 --- a/kernel/power/poweroff.c +++ b/kernel/power/poweroff.c @@ -32,7 +32,7 @@ static void handle_poweroff(int key) static struct sysrq_key_op sysrq_poweroff_op = { .handler = handle_poweroff, - .help_msg = "powerOff", + .help_msg = "poweroff(o)", .action_msg = "Power Off", .enable_mask = SYSRQ_ENABLE_BOOT, }; diff --git a/kernel/power/process.c b/kernel/power/process.c index d5a258b60c6f..98088e0e71e8 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -21,7 +21,7 @@ /* * Timeout for stopping processes */ -#define TIMEOUT (20 * HZ) +unsigned int __read_mostly freeze_timeout_msecs = 20 * MSEC_PER_SEC; static int try_to_freeze_tasks(bool user_only) { @@ -36,7 +36,7 @@ static int try_to_freeze_tasks(bool user_only) do_gettimeofday(&start); - end_time = jiffies + TIMEOUT; + end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs); if (!user_only) freeze_workqueues_begin(); diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 9322ff7eaad6..587dddeebf15 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -359,8 +359,7 @@ void pm_qos_update_request(struct pm_qos_request *req, return; } - if (delayed_work_pending(&req->work)) - cancel_delayed_work_sync(&req->work); + cancel_delayed_work_sync(&req->work); if (new_value != req->node.prio) pm_qos_update_target( @@ -386,8 +385,7 @@ void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, "%s called for unknown object.", __func__)) return; - if (delayed_work_pending(&req->work)) - cancel_delayed_work_sync(&req->work); + cancel_delayed_work_sync(&req->work); if (new_value != req->node.prio) pm_qos_update_target( @@ -416,8 +414,7 @@ void pm_qos_remove_request(struct pm_qos_request *req) return; } - if (delayed_work_pending(&req->work)) - cancel_delayed_work_sync(&req->work); + cancel_delayed_work_sync(&req->work); pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, &req->node, PM_QOS_REMOVE_REQ, diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index c8b7446b27df..bef86d121eb2 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -30,12 +30,38 @@ #include "power.h" const char *const pm_states[PM_SUSPEND_MAX] = { + [PM_SUSPEND_FREEZE] = "freeze", [PM_SUSPEND_STANDBY] = "standby", [PM_SUSPEND_MEM] = "mem", }; static const struct platform_suspend_ops *suspend_ops; +static bool need_suspend_ops(suspend_state_t state) +{ + return !!(state > PM_SUSPEND_FREEZE); +} + +static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head); +static bool suspend_freeze_wake; + +static void freeze_begin(void) +{ + suspend_freeze_wake = false; +} + +static void freeze_enter(void) +{ + wait_event(suspend_freeze_wait_head, suspend_freeze_wake); +} + +void freeze_wake(void) +{ + suspend_freeze_wake = true; + wake_up(&suspend_freeze_wait_head); +} +EXPORT_SYMBOL_GPL(freeze_wake); + /** * suspend_set_ops - Set the global suspend method table. * @ops: Suspend operations to use. @@ -50,8 +76,23 @@ EXPORT_SYMBOL_GPL(suspend_set_ops); bool valid_state(suspend_state_t state) { + if (state == PM_SUSPEND_FREEZE) { +#ifdef CONFIG_PM_DEBUG + if (pm_test_level != TEST_NONE && + pm_test_level != TEST_FREEZER && + pm_test_level != TEST_DEVICES && + pm_test_level != TEST_PLATFORM) { + printk(KERN_WARNING "Unsupported pm_test mode for " + "freeze state, please choose " + "none/freezer/devices/platform.\n"); + return false; + } +#endif + return true; + } /* - * All states need lowlevel support and need to be valid to the lowlevel + * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel + * support and need to be valid to the lowlevel * implementation, no valid callback implies that none are valid. */ return suspend_ops && suspend_ops->valid && suspend_ops->valid(state); @@ -89,11 +130,11 @@ static int suspend_test(int level) * hibernation). Run suspend notifiers, allocate the "suspend" console and * freeze processes. */ -static int suspend_prepare(void) +static int suspend_prepare(suspend_state_t state) { int error; - if (!suspend_ops || !suspend_ops->enter) + if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter)) return -EPERM; pm_prepare_console(); @@ -137,7 +178,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) { int error; - if (suspend_ops->prepare) { + if (need_suspend_ops(state) && suspend_ops->prepare) { error = suspend_ops->prepare(); if (error) goto Platform_finish; @@ -149,7 +190,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) goto Platform_finish; } - if (suspend_ops->prepare_late) { + if (need_suspend_ops(state) && suspend_ops->prepare_late) { error = suspend_ops->prepare_late(); if (error) goto Platform_wake; @@ -158,6 +199,17 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) if (suspend_test(TEST_PLATFORM)) goto Platform_wake; + /* + * PM_SUSPEND_FREEZE equals + * frozen processes + suspended devices + idle processors. + * Thus we should invoke freeze_enter() soon after + * all the devices are suspended. + */ + if (state == PM_SUSPEND_FREEZE) { + freeze_enter(); + goto Platform_wake; + } + error = disable_nonboot_cpus(); if (error || suspend_test(TEST_CPUS)) goto Enable_cpus; @@ -182,13 +234,13 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) enable_nonboot_cpus(); Platform_wake: - if (suspend_ops->wake) + if (need_suspend_ops(state) && suspend_ops->wake) suspend_ops->wake(); dpm_resume_start(PMSG_RESUME); Platform_finish: - if (suspend_ops->finish) + if (need_suspend_ops(state) && suspend_ops->finish) suspend_ops->finish(); return error; @@ -203,11 +255,11 @@ int suspend_devices_and_enter(suspend_state_t state) int error; bool wakeup = false; - if (!suspend_ops) + if (need_suspend_ops(state) && !suspend_ops) return -ENOSYS; trace_machine_suspend(state); - if (suspend_ops->begin) { + if (need_suspend_ops(state) && suspend_ops->begin) { error = suspend_ops->begin(state); if (error) goto Close; @@ -226,7 +278,7 @@ int suspend_devices_and_enter(suspend_state_t state) do { error = suspend_enter(state, &wakeup); - } while (!error && !wakeup + } while (!error && !wakeup && need_suspend_ops(state) && suspend_ops->suspend_again && suspend_ops->suspend_again()); Resume_devices: @@ -236,13 +288,13 @@ int suspend_devices_and_enter(suspend_state_t state) ftrace_start(); resume_console(); Close: - if (suspend_ops->end) + if (need_suspend_ops(state) && suspend_ops->end) suspend_ops->end(); trace_machine_suspend(PWR_EVENT_EXIT); return error; Recover_platform: - if (suspend_ops->recover) + if (need_suspend_ops(state) && suspend_ops->recover) suspend_ops->recover(); goto Resume_devices; } @@ -278,12 +330,15 @@ static int enter_state(suspend_state_t state) if (!mutex_trylock(&pm_mutex)) return -EBUSY; + if (state == PM_SUSPEND_FREEZE) + freeze_begin(); + printk(KERN_INFO "PM: Syncing filesystems ... "); sys_sync(); printk("done.\n"); pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); - error = suspend_prepare(); + error = suspend_prepare(state); if (error) goto Unlock; diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c index 25596e450ac7..9b2a1d58558d 100644 --- a/kernel/power/suspend_test.c +++ b/kernel/power/suspend_test.c @@ -112,7 +112,7 @@ static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state) rtc_set_alarm(rtc, &alm); } -static int __init has_wakealarm(struct device *dev, void *name_ptr) +static int __init has_wakealarm(struct device *dev, const void *data) { struct rtc_device *candidate = to_rtc_device(dev); @@ -121,7 +121,6 @@ static int __init has_wakealarm(struct device *dev, void *name_ptr) if (!device_may_wakeup(candidate->dev.parent)) return 0; - *(const char **)name_ptr = dev_name(dev); return 1; } @@ -159,8 +158,8 @@ static int __init test_suspend(void) static char warn_no_rtc[] __initdata = KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n"; - char *pony = NULL; struct rtc_device *rtc = NULL; + struct device *dev; /* PM is initialized by now; is that state testable? */ if (test_state == PM_SUSPEND_ON) @@ -171,9 +170,9 @@ static int __init test_suspend(void) } /* RTCs have initialized by now too ... can we use one? */ - class_find_device(rtc_class, NULL, &pony, has_wakealarm); - if (pony) - rtc = rtc_class_open(pony); + dev = class_find_device(rtc_class, NULL, NULL, has_wakealarm); + if (dev) + rtc = rtc_class_open(dev_name(dev)); if (!rtc) { printk(warn_no_rtc); goto done; diff --git a/kernel/printk.c b/kernel/printk.c index 267ce780abe8..fa36e1494420 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -32,6 +32,7 @@ #include <linux/security.h> #include <linux/bootmem.h> #include <linux/memblock.h> +#include <linux/aio.h> #include <linux/syscalls.h> #include <linux/kexec.h> #include <linux/kdb.h> @@ -42,19 +43,14 @@ #include <linux/notifier.h> #include <linux/rculist.h> #include <linux/poll.h> +#include <linux/irq_work.h> +#include <linux/utsname.h> #include <asm/uaccess.h> #define CREATE_TRACE_POINTS #include <trace/events/printk.h> -/* - * Architectures can override it: - */ -void asmlinkage __attribute__((weak)) early_printk(const char *fmt, ...) -{ -} - /* printk's without a loglevel use this.. */ #define DEFAULT_MESSAGE_LOGLEVEL CONFIG_DEFAULT_MESSAGE_LOGLEVEL @@ -62,8 +58,6 @@ void asmlinkage __attribute__((weak)) early_printk(const char *fmt, ...) #define MINIMUM_CONSOLE_LOGLEVEL 1 /* Minimum loglevel we let people use */ #define DEFAULT_CONSOLE_LOGLEVEL 7 /* anything MORE serious than KERN_DEBUG */ -DECLARE_WAIT_QUEUE_HEAD(log_wait); - int console_printk[4] = { DEFAULT_CONSOLE_LOGLEVEL, /* console_loglevel */ DEFAULT_MESSAGE_LOGLEVEL, /* default_message_loglevel */ @@ -87,6 +81,12 @@ static DEFINE_SEMAPHORE(console_sem); struct console *console_drivers; EXPORT_SYMBOL_GPL(console_drivers); +#ifdef CONFIG_LOCKDEP +static struct lockdep_map console_lock_dep_map = { + .name = "console_lock" +}; +#endif + /* * This is used for debugging the mess that is the VT code by * keeping track if we have the console semaphore held. It's @@ -217,6 +217,7 @@ struct log { static DEFINE_RAW_SPINLOCK(logbuf_lock); #ifdef CONFIG_PRINTK +DECLARE_WAIT_QUEUE_HEAD(log_wait); /* the next printk record to read by syslog(READ) or /proc/kmsg */ static u64 syslog_seq; static u32 syslog_idx; @@ -602,7 +603,8 @@ static unsigned int devkmsg_poll(struct file *file, poll_table *wait) /* return error when data has vanished underneath us */ if (user->seq < log_first_seq) ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI; - ret = POLLIN|POLLRDNORM; + else + ret = POLLIN|POLLRDNORM; } raw_spin_unlock_irq(&logbuf_lock); @@ -1259,7 +1261,7 @@ static void call_console_drivers(int level, const char *text, size_t len) { struct console *con; - trace_console(text, 0, len, len); + trace_console(text, len); if (level >= console_loglevel && !ignore_loglevel) return; @@ -1717,6 +1719,29 @@ static size_t cont_print_text(char *text, size_t size) { return 0; } #endif /* CONFIG_PRINTK */ +#ifdef CONFIG_EARLY_PRINTK +struct console *early_console; + +void early_vprintk(const char *fmt, va_list ap) +{ + if (early_console) { + char buf[512]; + int n = vscnprintf(buf, sizeof(buf), fmt, ap); + + early_console->write(early_console, buf, n); + } +} + +asmlinkage void early_printk(const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + early_vprintk(fmt, ap); + va_end(ap); +} +#endif + static int __add_preferred_console(char *name, int idx, char *options, char *brl_options) { @@ -1918,6 +1943,7 @@ void console_lock(void) return; console_locked = 1; console_may_schedule = 1; + mutex_acquire(&console_lock_dep_map, 0, 0, _RET_IP_); } EXPORT_SYMBOL(console_lock); @@ -1939,6 +1965,7 @@ int console_trylock(void) } console_locked = 1; console_may_schedule = 0; + mutex_acquire(&console_lock_dep_map, 0, 1, _RET_IP_); return 1; } EXPORT_SYMBOL(console_trylock); @@ -1948,43 +1975,6 @@ int is_console_locked(void) return console_locked; } -/* - * Delayed printk version, for scheduler-internal messages: - */ -#define PRINTK_BUF_SIZE 512 - -#define PRINTK_PENDING_WAKEUP 0x01 -#define PRINTK_PENDING_SCHED 0x02 - -static DEFINE_PER_CPU(int, printk_pending); -static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf); - -void printk_tick(void) -{ - if (__this_cpu_read(printk_pending)) { - int pending = __this_cpu_xchg(printk_pending, 0); - if (pending & PRINTK_PENDING_SCHED) { - char *buf = __get_cpu_var(printk_sched_buf); - printk(KERN_WARNING "[sched_delayed] %s", buf); - } - if (pending & PRINTK_PENDING_WAKEUP) - wake_up_interruptible(&log_wait); - } -} - -int printk_needs_cpu(int cpu) -{ - if (cpu_is_offline(cpu)) - printk_tick(); - return __this_cpu_read(printk_pending); -} - -void wake_up_klogd(void) -{ - if (waitqueue_active(&log_wait)) - this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP); -} - static void console_cont_flush(char *text, size_t size) { unsigned long flags; @@ -2099,6 +2089,7 @@ skip: local_irq_restore(flags); } console_locked = 0; + mutex_release(&console_lock_dep_map, 1, _RET_IP_); /* Release the exclusive_console once it is used */ if (unlikely(exclusive_console)) @@ -2446,6 +2437,44 @@ static int __init printk_late_init(void) late_initcall(printk_late_init); #if defined CONFIG_PRINTK +/* + * Delayed printk version, for scheduler-internal messages: + */ +#define PRINTK_BUF_SIZE 512 + +#define PRINTK_PENDING_WAKEUP 0x01 +#define PRINTK_PENDING_SCHED 0x02 + +static DEFINE_PER_CPU(int, printk_pending); +static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf); + +static void wake_up_klogd_work_func(struct irq_work *irq_work) +{ + int pending = __this_cpu_xchg(printk_pending, 0); + + if (pending & PRINTK_PENDING_SCHED) { + char *buf = __get_cpu_var(printk_sched_buf); + printk(KERN_WARNING "[sched_delayed] %s", buf); + } + + if (pending & PRINTK_PENDING_WAKEUP) + wake_up_interruptible(&log_wait); +} + +static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) = { + .func = wake_up_klogd_work_func, + .flags = IRQ_WORK_LAZY, +}; + +void wake_up_klogd(void) +{ + preempt_disable(); + if (waitqueue_active(&log_wait)) { + this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP); + irq_work_queue(&__get_cpu_var(wake_up_klogd_work)); + } + preempt_enable(); +} int printk_sched(const char *fmt, ...) { @@ -2462,6 +2491,7 @@ int printk_sched(const char *fmt, ...) va_end(args); __this_cpu_or(printk_pending, PRINTK_PENDING_SCHED); + irq_work_queue(&__get_cpu_var(wake_up_klogd_work)); local_irq_restore(flags); return r; @@ -2821,4 +2851,65 @@ void kmsg_dump_rewind(struct kmsg_dumper *dumper) raw_spin_unlock_irqrestore(&logbuf_lock, flags); } EXPORT_SYMBOL_GPL(kmsg_dump_rewind); + +static char dump_stack_arch_desc_str[128]; + +/** + * dump_stack_set_arch_desc - set arch-specific str to show with task dumps + * @fmt: printf-style format string + * @...: arguments for the format string + * + * The configured string will be printed right after utsname during task + * dumps. Usually used to add arch-specific system identifiers. If an + * arch wants to make use of such an ID string, it should initialize this + * as soon as possible during boot. + */ +void __init dump_stack_set_arch_desc(const char *fmt, ...) +{ + va_list args; + + va_start(args, fmt); + vsnprintf(dump_stack_arch_desc_str, sizeof(dump_stack_arch_desc_str), + fmt, args); + va_end(args); +} + +/** + * dump_stack_print_info - print generic debug info for dump_stack() + * @log_lvl: log level + * + * Arch-specific dump_stack() implementations can use this function to + * print out the same debug information as the generic dump_stack(). + */ +void dump_stack_print_info(const char *log_lvl) +{ + printk("%sCPU: %d PID: %d Comm: %.20s %s %s %.*s\n", + log_lvl, raw_smp_processor_id(), current->pid, current->comm, + print_tainted(), init_utsname()->release, + (int)strcspn(init_utsname()->version, " "), + init_utsname()->version); + + if (dump_stack_arch_desc_str[0] != '\0') + printk("%sHardware name: %s\n", + log_lvl, dump_stack_arch_desc_str); + + print_worker_info(log_lvl, current); +} + +/** + * show_regs_print_info - print generic debug info for show_regs() + * @log_lvl: log level + * + * show_regs() implementations can use this function to print out generic + * debug information. + */ +void show_regs_print_info(const char *log_lvl) +{ + dump_stack_print_info(log_lvl); + + printk("%stask: %p ti: %p task.ti: %p\n", + log_lvl, current, current_thread_info(), + task_thread_info(current)); +} + #endif diff --git a/kernel/profile.c b/kernel/profile.c index 1f391819c42f..0bf400737660 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -37,9 +37,6 @@ struct profile_hit { #define NR_PROFILE_HIT (PAGE_SIZE/sizeof(struct profile_hit)) #define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ) -/* Oprofile timer tick hook */ -static int (*timer_hook)(struct pt_regs *) __read_mostly; - static atomic_t *prof_buffer; static unsigned long prof_len, prof_shift; @@ -208,25 +205,6 @@ int profile_event_unregister(enum profile_type type, struct notifier_block *n) } EXPORT_SYMBOL_GPL(profile_event_unregister); -int register_timer_hook(int (*hook)(struct pt_regs *)) -{ - if (timer_hook) - return -EBUSY; - timer_hook = hook; - return 0; -} -EXPORT_SYMBOL_GPL(register_timer_hook); - -void unregister_timer_hook(int (*hook)(struct pt_regs *)) -{ - WARN_ON(hook != timer_hook); - timer_hook = NULL; - /* make sure all CPUs see the NULL hook */ - synchronize_sched(); /* Allow ongoing interrupts to complete. */ -} -EXPORT_SYMBOL_GPL(unregister_timer_hook); - - #ifdef CONFIG_SMP /* * Each cpu has a pair of open-addressed hashtables for pending @@ -436,8 +414,6 @@ void profile_tick(int type) { struct pt_regs *regs = get_irq_regs(); - if (type == CPU_PROFILING && timer_hook) - timer_hook(regs); if (!user_mode(regs) && prof_cpu_mask != NULL && cpumask_test_cpu(smp_processor_id(), prof_cpu_mask)) profile_hit(type, (void *)profile_pc(regs)); @@ -486,10 +462,10 @@ static const struct file_operations prof_cpu_mask_proc_fops = { .write = prof_cpu_mask_proc_write, }; -void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir) +void create_prof_cpu_mask(void) { /* create /proc/irq/prof_cpu_mask */ - proc_create("prof_cpu_mask", 0600, root_irq_dir, &prof_cpu_mask_proc_fops); + proc_create("irq/prof_cpu_mask", 0600, NULL, &prof_cpu_mask_proc_fops); } /* @@ -624,7 +600,7 @@ int __ref create_proc_profile(void) /* false positive from hotcpu_notifier */ NULL, &proc_profile_operations); if (!entry) return 0; - entry->size = (1+prof_len) * sizeof(atomic_t); + proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t)); hotcpu_notifier(profile_cpu_callback, 0); return 0; } diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 6cbeaae4406d..aed981a3f69c 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -17,6 +17,7 @@ #include <linux/ptrace.h> #include <linux/security.h> #include <linux/signal.h> +#include <linux/uio.h> #include <linux/audit.h> #include <linux/pid_namespace.h> #include <linux/syscalls.h> @@ -24,6 +25,7 @@ #include <linux/regset.h> #include <linux/hw_breakpoint.h> #include <linux/cn_proc.h> +#include <linux/compat.h> static int ptrace_trapping_sleep_fn(void *flags) @@ -618,6 +620,81 @@ static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) return error; } +static int ptrace_peek_siginfo(struct task_struct *child, + unsigned long addr, + unsigned long data) +{ + struct ptrace_peeksiginfo_args arg; + struct sigpending *pending; + struct sigqueue *q; + int ret, i; + + ret = copy_from_user(&arg, (void __user *) addr, + sizeof(struct ptrace_peeksiginfo_args)); + if (ret) + return -EFAULT; + + if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) + return -EINVAL; /* unknown flags */ + + if (arg.nr < 0) + return -EINVAL; + + if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) + pending = &child->signal->shared_pending; + else + pending = &child->pending; + + for (i = 0; i < arg.nr; ) { + siginfo_t info; + s32 off = arg.off + i; + + spin_lock_irq(&child->sighand->siglock); + list_for_each_entry(q, &pending->list, list) { + if (!off--) { + copy_siginfo(&info, &q->info); + break; + } + } + spin_unlock_irq(&child->sighand->siglock); + + if (off >= 0) /* beyond the end of the list */ + break; + +#ifdef CONFIG_COMPAT + if (unlikely(is_compat_task())) { + compat_siginfo_t __user *uinfo = compat_ptr(data); + + ret = copy_siginfo_to_user32(uinfo, &info); + ret |= __put_user(info.si_code, &uinfo->si_code); + } else +#endif + { + siginfo_t __user *uinfo = (siginfo_t __user *) data; + + ret = copy_siginfo_to_user(uinfo, &info); + ret |= __put_user(info.si_code, &uinfo->si_code); + } + + if (ret) { + ret = -EFAULT; + break; + } + + data += sizeof(siginfo_t); + i++; + + if (signal_pending(current)) + break; + + cond_resched(); + } + + if (i > 0) + return i; + + return ret; +} #ifdef PTRACE_SINGLESTEP #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) @@ -712,6 +789,12 @@ static int ptrace_regset(struct task_struct *task, int req, unsigned int type, kiov->iov_len, kiov->iov_base); } +/* + * This is declared in linux/regset.h and defined in machine-dependent + * code. We put the export here, near the primary machine-neutral use, + * to ensure no machine forgets it. + */ +EXPORT_SYMBOL_GPL(task_user_regset_view); #endif int ptrace_request(struct task_struct *child, long request, @@ -742,6 +825,10 @@ int ptrace_request(struct task_struct *child, long request, ret = put_user(child->ptrace_message, datalp); break; + case PTRACE_PEEKSIGINFO: + ret = ptrace_peek_siginfo(child, addr, data); + break; + case PTRACE_GETSIGINFO: ret = ptrace_getsiginfo(child, &siginfo); if (!ret) diff --git a/kernel/range.c b/kernel/range.c index 9b8ae2d6ed68..071b0ab455cb 100644 --- a/kernel/range.c +++ b/kernel/range.c @@ -97,7 +97,8 @@ void subtract_range(struct range *range, int az, u64 start, u64 end) range[i].end = range[j].end; range[i].start = end; } else { - printk(KERN_ERR "run of slot in ranges\n"); + pr_err("%s: run out of slot in ranges\n", + __func__); } range[j].end = start; continue; diff --git a/kernel/rcu.h b/kernel/rcu.h index 20dfba576c2b..7f8e7590e3e5 100644 --- a/kernel/rcu.h +++ b/kernel/rcu.h @@ -111,4 +111,11 @@ static inline bool __rcu_reclaim(char *rn, struct rcu_head *head) extern int rcu_expedited; +#ifdef CONFIG_RCU_STALL_COMMON + +extern int rcu_cpu_stall_suppress; +int rcu_jiffies_till_stall_check(void); + +#endif /* #ifdef CONFIG_RCU_STALL_COMMON */ + #endif /* __LINUX_RCU_H */ diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index a2cf76177b44..48ab70384a4c 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -404,11 +404,65 @@ EXPORT_SYMBOL_GPL(rcuhead_debug_descr); #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ #if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU) || defined(CONFIG_RCU_TRACE) -void do_trace_rcu_torture_read(char *rcutorturename, struct rcu_head *rhp) +void do_trace_rcu_torture_read(char *rcutorturename, struct rcu_head *rhp, + unsigned long secs, + unsigned long c_old, unsigned long c) { - trace_rcu_torture_read(rcutorturename, rhp); + trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c); } EXPORT_SYMBOL_GPL(do_trace_rcu_torture_read); #else -#define do_trace_rcu_torture_read(rcutorturename, rhp) do { } while (0) +#define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \ + do { } while (0) #endif + +#ifdef CONFIG_RCU_STALL_COMMON + +#ifdef CONFIG_PROVE_RCU +#define RCU_STALL_DELAY_DELTA (5 * HZ) +#else +#define RCU_STALL_DELAY_DELTA 0 +#endif + +int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */ +int rcu_cpu_stall_timeout __read_mostly = CONFIG_RCU_CPU_STALL_TIMEOUT; + +module_param(rcu_cpu_stall_suppress, int, 0644); +module_param(rcu_cpu_stall_timeout, int, 0644); + +int rcu_jiffies_till_stall_check(void) +{ + int till_stall_check = ACCESS_ONCE(rcu_cpu_stall_timeout); + + /* + * Limit check must be consistent with the Kconfig limits + * for CONFIG_RCU_CPU_STALL_TIMEOUT. + */ + if (till_stall_check < 3) { + ACCESS_ONCE(rcu_cpu_stall_timeout) = 3; + till_stall_check = 3; + } else if (till_stall_check > 300) { + ACCESS_ONCE(rcu_cpu_stall_timeout) = 300; + till_stall_check = 300; + } + return till_stall_check * HZ + RCU_STALL_DELAY_DELTA; +} + +static int rcu_panic(struct notifier_block *this, unsigned long ev, void *ptr) +{ + rcu_cpu_stall_suppress = 1; + return NOTIFY_DONE; +} + +static struct notifier_block rcu_panic_block = { + .notifier_call = rcu_panic, +}; + +static int __init check_cpu_stall_init(void) +{ + atomic_notifier_chain_register(&panic_notifier_list, &rcu_panic_block); + return 0; +} +early_initcall(check_cpu_stall_init); + +#endif /* #ifdef CONFIG_RCU_STALL_COMMON */ diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c index e7dce58f9c2a..a0714a51b6d7 100644 --- a/kernel/rcutiny.c +++ b/kernel/rcutiny.c @@ -51,10 +51,10 @@ static void __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu), struct rcu_ctrlblk *rcp); -#include "rcutiny_plugin.h" - static long long rcu_dynticks_nesting = DYNTICK_TASK_EXIT_IDLE; +#include "rcutiny_plugin.h" + /* Common code for rcu_idle_enter() and rcu_irq_exit(), see kernel/rcutree.c. */ static void rcu_idle_enter_common(long long newval) { @@ -193,7 +193,7 @@ EXPORT_SYMBOL(rcu_is_cpu_idle); * interrupts don't count, we must be running at the first interrupt * level. */ -int rcu_is_cpu_rrupt_from_idle(void) +static int rcu_is_cpu_rrupt_from_idle(void) { return rcu_dynticks_nesting <= 1; } @@ -205,6 +205,7 @@ int rcu_is_cpu_rrupt_from_idle(void) */ static int rcu_qsctr_help(struct rcu_ctrlblk *rcp) { + reset_cpu_stall_ticks(rcp); if (rcp->rcucblist != NULL && rcp->donetail != rcp->curtail) { rcp->donetail = rcp->curtail; @@ -251,6 +252,7 @@ void rcu_bh_qs(int cpu) */ void rcu_check_callbacks(int cpu, int user) { + check_cpu_stalls(); if (user || rcu_is_cpu_rrupt_from_idle()) rcu_sched_qs(cpu); else if (!in_softirq()) diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h index f85016a2309b..8a233002faeb 100644 --- a/kernel/rcutiny_plugin.h +++ b/kernel/rcutiny_plugin.h @@ -33,6 +33,9 @@ struct rcu_ctrlblk { struct rcu_head **donetail; /* ->next pointer of last "done" CB. */ struct rcu_head **curtail; /* ->next pointer of last CB. */ RCU_TRACE(long qlen); /* Number of pending CBs. */ + RCU_TRACE(unsigned long gp_start); /* Start time for stalls. */ + RCU_TRACE(unsigned long ticks_this_gp); /* Statistic for stalls. */ + RCU_TRACE(unsigned long jiffies_stall); /* Jiffies at next stall. */ RCU_TRACE(char *name); /* Name of RCU type. */ }; @@ -54,6 +57,51 @@ int rcu_scheduler_active __read_mostly; EXPORT_SYMBOL_GPL(rcu_scheduler_active); #endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ +#ifdef CONFIG_RCU_TRACE + +static void check_cpu_stall(struct rcu_ctrlblk *rcp) +{ + unsigned long j; + unsigned long js; + + if (rcu_cpu_stall_suppress) + return; + rcp->ticks_this_gp++; + j = jiffies; + js = rcp->jiffies_stall; + if (*rcp->curtail && ULONG_CMP_GE(j, js)) { + pr_err("INFO: %s stall on CPU (%lu ticks this GP) idle=%llx (t=%lu jiffies q=%ld)\n", + rcp->name, rcp->ticks_this_gp, rcu_dynticks_nesting, + jiffies - rcp->gp_start, rcp->qlen); + dump_stack(); + } + if (*rcp->curtail && ULONG_CMP_GE(j, js)) + rcp->jiffies_stall = jiffies + + 3 * rcu_jiffies_till_stall_check() + 3; + else if (ULONG_CMP_GE(j, js)) + rcp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check(); +} + +static void check_cpu_stall_preempt(void); + +#endif /* #ifdef CONFIG_RCU_TRACE */ + +static void reset_cpu_stall_ticks(struct rcu_ctrlblk *rcp) +{ +#ifdef CONFIG_RCU_TRACE + rcp->ticks_this_gp = 0; + rcp->gp_start = jiffies; + rcp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check(); +#endif /* #ifdef CONFIG_RCU_TRACE */ +} + +static void check_cpu_stalls(void) +{ + RCU_TRACE(check_cpu_stall(&rcu_bh_ctrlblk)); + RCU_TRACE(check_cpu_stall(&rcu_sched_ctrlblk)); + RCU_TRACE(check_cpu_stall_preempt()); +} + #ifdef CONFIG_TINY_PREEMPT_RCU #include <linux/delay.h> @@ -448,6 +496,7 @@ static void rcu_preempt_start_gp(void) /* Official start of GP. */ rcu_preempt_ctrlblk.gpnum++; RCU_TRACE(rcu_preempt_ctrlblk.n_grace_periods++); + reset_cpu_stall_ticks(&rcu_preempt_ctrlblk.rcb); /* Any blocked RCU readers block new GP. */ if (rcu_preempt_blocked_readers_any()) @@ -1054,4 +1103,11 @@ MODULE_AUTHOR("Paul E. McKenney"); MODULE_DESCRIPTION("Read-Copy Update tracing for tiny implementation"); MODULE_LICENSE("GPL"); +static void check_cpu_stall_preempt(void) +{ +#ifdef CONFIG_TINY_PREEMPT_RCU + check_cpu_stall(&rcu_preempt_ctrlblk.rcb); +#endif /* #ifdef CONFIG_TINY_PREEMPT_RCU */ +} + #endif /* #ifdef CONFIG_RCU_TRACE */ diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 31dea01c85fd..e1f3a8c96724 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -46,6 +46,7 @@ #include <linux/stat.h> #include <linux/srcu.h> #include <linux/slab.h> +#include <linux/trace_clock.h> #include <asm/byteorder.h> MODULE_LICENSE("GPL"); @@ -207,6 +208,20 @@ MODULE_PARM_DESC(rcutorture_runnable, "Start rcutorture at boot"); #define rcu_can_boost() 0 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ +#ifdef CONFIG_RCU_TRACE +static u64 notrace rcu_trace_clock_local(void) +{ + u64 ts = trace_clock_local(); + unsigned long __maybe_unused ts_rem = do_div(ts, NSEC_PER_USEC); + return ts; +} +#else /* #ifdef CONFIG_RCU_TRACE */ +static u64 notrace rcu_trace_clock_local(void) +{ + return 0ULL; +} +#endif /* #else #ifdef CONFIG_RCU_TRACE */ + static unsigned long shutdown_time; /* jiffies to system shutdown. */ static unsigned long boost_starttime; /* jiffies of next boost test start. */ DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ @@ -845,7 +860,7 @@ static int rcu_torture_boost(void *arg) /* Wait for the next test interval. */ oldstarttime = boost_starttime; while (ULONG_CMP_LT(jiffies, oldstarttime)) { - schedule_timeout_uninterruptible(1); + schedule_timeout_interruptible(oldstarttime - jiffies); rcu_stutter_wait("rcu_torture_boost"); if (kthread_should_stop() || fullstop != FULLSTOP_DONTSTOP) @@ -1028,7 +1043,6 @@ void rcutorture_trace_dump(void) return; if (atomic_xchg(&beenhere, 1) != 0) return; - do_trace_rcu_torture_read(cur_ops->name, (struct rcu_head *)~0UL); ftrace_dump(DUMP_ALL); } @@ -1042,13 +1056,16 @@ static void rcu_torture_timer(unsigned long unused) { int idx; int completed; + int completed_end; static DEFINE_RCU_RANDOM(rand); static DEFINE_SPINLOCK(rand_lock); struct rcu_torture *p; int pipe_count; + unsigned long long ts; idx = cur_ops->readlock(); completed = cur_ops->completed(); + ts = rcu_trace_clock_local(); p = rcu_dereference_check(rcu_torture_current, rcu_read_lock_bh_held() || rcu_read_lock_sched_held() || @@ -1058,7 +1075,6 @@ static void rcu_torture_timer(unsigned long unused) cur_ops->readunlock(idx); return; } - do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu); if (p->rtort_mbtest == 0) atomic_inc(&n_rcu_torture_mberror); spin_lock(&rand_lock); @@ -1071,10 +1087,14 @@ static void rcu_torture_timer(unsigned long unused) /* Should not happen, but... */ pipe_count = RCU_TORTURE_PIPE_LEN; } - if (pipe_count > 1) + completed_end = cur_ops->completed(); + if (pipe_count > 1) { + do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts, + completed, completed_end); rcutorture_trace_dump(); + } __this_cpu_inc(rcu_torture_count[pipe_count]); - completed = cur_ops->completed() - completed; + completed = completed_end - completed; if (completed > RCU_TORTURE_PIPE_LEN) { /* Should not happen, but... */ completed = RCU_TORTURE_PIPE_LEN; @@ -1094,11 +1114,13 @@ static int rcu_torture_reader(void *arg) { int completed; + int completed_end; int idx; DEFINE_RCU_RANDOM(rand); struct rcu_torture *p; int pipe_count; struct timer_list t; + unsigned long long ts; VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); set_user_nice(current, 19); @@ -1112,6 +1134,7 @@ rcu_torture_reader(void *arg) } idx = cur_ops->readlock(); completed = cur_ops->completed(); + ts = rcu_trace_clock_local(); p = rcu_dereference_check(rcu_torture_current, rcu_read_lock_bh_held() || rcu_read_lock_sched_held() || @@ -1122,7 +1145,6 @@ rcu_torture_reader(void *arg) schedule_timeout_interruptible(HZ); continue; } - do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu); if (p->rtort_mbtest == 0) atomic_inc(&n_rcu_torture_mberror); cur_ops->read_delay(&rand); @@ -1132,10 +1154,14 @@ rcu_torture_reader(void *arg) /* Should not happen, but... */ pipe_count = RCU_TORTURE_PIPE_LEN; } - if (pipe_count > 1) + completed_end = cur_ops->completed(); + if (pipe_count > 1) { + do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, + ts, completed, completed_end); rcutorture_trace_dump(); + } __this_cpu_inc(rcu_torture_count[pipe_count]); - completed = cur_ops->completed() - completed; + completed = completed_end - completed; if (completed > RCU_TORTURE_PIPE_LEN) { /* Should not happen, but... */ completed = RCU_TORTURE_PIPE_LEN; @@ -1301,19 +1327,35 @@ static void rcu_torture_shuffle_tasks(void) set_cpus_allowed_ptr(reader_tasks[i], shuffle_tmp_mask); } - if (fakewriter_tasks) { for (i = 0; i < nfakewriters; i++) if (fakewriter_tasks[i]) set_cpus_allowed_ptr(fakewriter_tasks[i], shuffle_tmp_mask); } - if (writer_task) set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask); - if (stats_task) set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask); + if (stutter_task) + set_cpus_allowed_ptr(stutter_task, shuffle_tmp_mask); + if (fqs_task) + set_cpus_allowed_ptr(fqs_task, shuffle_tmp_mask); + if (shutdown_task) + set_cpus_allowed_ptr(shutdown_task, shuffle_tmp_mask); +#ifdef CONFIG_HOTPLUG_CPU + if (onoff_task) + set_cpus_allowed_ptr(onoff_task, shuffle_tmp_mask); +#endif /* #ifdef CONFIG_HOTPLUG_CPU */ + if (stall_task) + set_cpus_allowed_ptr(stall_task, shuffle_tmp_mask); + if (barrier_cbs_tasks) + for (i = 0; i < n_barrier_cbs; i++) + if (barrier_cbs_tasks[i]) + set_cpus_allowed_ptr(barrier_cbs_tasks[i], + shuffle_tmp_mask); + if (barrier_task) + set_cpus_allowed_ptr(barrier_task, shuffle_tmp_mask); if (rcu_idle_cpu == -1) rcu_idle_cpu = num_online_cpus() - 1; @@ -1749,7 +1791,7 @@ static int rcu_torture_barrier_init(void) barrier_cbs_wq = kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]), GFP_KERNEL); - if (barrier_cbs_tasks == NULL || barrier_cbs_wq == 0) + if (barrier_cbs_tasks == NULL || !barrier_cbs_wq) return -ENOMEM; for (i = 0; i < n_barrier_cbs; i++) { init_waitqueue_head(&barrier_cbs_wq[i]); diff --git a/kernel/rcutree.c b/kernel/rcutree.c index e441b77b614e..16ea67925015 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -64,7 +64,7 @@ static struct lock_class_key rcu_node_class[RCU_NUM_LVLS]; static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS]; -#define RCU_STATE_INITIALIZER(sname, cr) { \ +#define RCU_STATE_INITIALIZER(sname, sabbr, cr) { \ .level = { &sname##_state.node[0] }, \ .call = cr, \ .fqs_state = RCU_GP_IDLE, \ @@ -76,13 +76,14 @@ static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS]; .barrier_mutex = __MUTEX_INITIALIZER(sname##_state.barrier_mutex), \ .onoff_mutex = __MUTEX_INITIALIZER(sname##_state.onoff_mutex), \ .name = #sname, \ + .abbr = sabbr, \ } struct rcu_state rcu_sched_state = - RCU_STATE_INITIALIZER(rcu_sched, call_rcu_sched); + RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched); DEFINE_PER_CPU(struct rcu_data, rcu_sched_data); -struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh, call_rcu_bh); +struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh, 'b', call_rcu_bh); DEFINE_PER_CPU(struct rcu_data, rcu_bh_data); static struct rcu_state *rcu_state; @@ -105,7 +106,7 @@ int rcu_num_nodes __read_mostly = NUM_RCU_NODES; /* Total # rcu_nodes in use. */ * The rcu_scheduler_active variable transitions from zero to one just * before the first task is spawned. So when this variable is zero, RCU * can assume that there is but one task, allowing RCU to (for example) - * optimized synchronize_sched() to a simple barrier(). When this variable + * optimize synchronize_sched() to a simple barrier(). When this variable * is one, RCU must actually do all the hard work required to detect real * grace periods. This variable is also used to suppress boot-time false * positives from lockdep-RCU error checking. @@ -217,18 +218,14 @@ module_param(blimit, long, 0444); module_param(qhimark, long, 0444); module_param(qlowmark, long, 0444); -int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */ -int rcu_cpu_stall_timeout __read_mostly = CONFIG_RCU_CPU_STALL_TIMEOUT; - -module_param(rcu_cpu_stall_suppress, int, 0644); -module_param(rcu_cpu_stall_timeout, int, 0644); - static ulong jiffies_till_first_fqs = RCU_JIFFIES_TILL_FORCE_QS; static ulong jiffies_till_next_fqs = RCU_JIFFIES_TILL_FORCE_QS; module_param(jiffies_till_first_fqs, ulong, 0644); module_param(jiffies_till_next_fqs, ulong, 0644); +static void rcu_start_gp_advanced(struct rcu_state *rsp, struct rcu_node *rnp, + struct rcu_data *rdp); static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *)); static void force_quiescent_state(struct rcu_state *rsp); static int rcu_pending(int cpu); @@ -305,17 +302,29 @@ cpu_has_callbacks_ready_to_invoke(struct rcu_data *rdp) } /* - * Does the current CPU require a yet-as-unscheduled grace period? + * Does the current CPU require a not-yet-started grace period? + * The caller must have disabled interrupts to prevent races with + * normal callback registry. */ static int cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp) { - struct rcu_head **ntp; + int i; - ntp = rdp->nxttail[RCU_DONE_TAIL + - (ACCESS_ONCE(rsp->completed) != rdp->completed)]; - return rdp->nxttail[RCU_DONE_TAIL] && ntp && *ntp && - !rcu_gp_in_progress(rsp); + if (rcu_gp_in_progress(rsp)) + return 0; /* No, a grace period is already in progress. */ + if (rcu_nocb_needs_gp(rsp)) + return 1; /* Yes, a no-CBs CPU needs one. */ + if (!rdp->nxttail[RCU_NEXT_TAIL]) + return 0; /* No, this is a no-CBs (or offline) CPU. */ + if (*rdp->nxttail[RCU_NEXT_READY_TAIL]) + return 1; /* Yes, this CPU has newly registered callbacks. */ + for (i = RCU_WAIT_TAIL; i < RCU_NEXT_TAIL; i++) + if (rdp->nxttail[i - 1] != rdp->nxttail[i] && + ULONG_CMP_LT(ACCESS_ONCE(rsp->completed), + rdp->nxtcompleted[i])) + return 1; /* Yes, CBs for future grace period. */ + return 0; /* No grace period needed. */ } /* @@ -336,7 +345,7 @@ static struct rcu_node *rcu_get_root(struct rcu_state *rsp) static void rcu_eqs_enter_common(struct rcu_dynticks *rdtp, long long oldval, bool user) { - trace_rcu_dyntick("Start", oldval, 0); + trace_rcu_dyntick("Start", oldval, rdtp->dynticks_nesting); if (!user && !is_idle_task(current)) { struct task_struct *idle = idle_task(smp_processor_id()); @@ -727,7 +736,7 @@ EXPORT_SYMBOL_GPL(rcu_lockdep_current_cpu_online); * interrupt from idle, return true. The caller must have at least * disabled preemption. */ -int rcu_is_cpu_rrupt_from_idle(void) +static int rcu_is_cpu_rrupt_from_idle(void) { return __get_cpu_var(rcu_dynticks).dynticks_nesting <= 1; } @@ -790,31 +799,23 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) rdp->offline_fqs++; return 1; } - return 0; -} - -static int jiffies_till_stall_check(void) -{ - int till_stall_check = ACCESS_ONCE(rcu_cpu_stall_timeout); /* - * Limit check must be consistent with the Kconfig limits - * for CONFIG_RCU_CPU_STALL_TIMEOUT. + * There is a possibility that a CPU in adaptive-ticks state + * might run in the kernel with the scheduling-clock tick disabled + * for an extended time period. Invoke rcu_kick_nohz_cpu() to + * force the CPU to restart the scheduling-clock tick in this + * CPU is in this state. */ - if (till_stall_check < 3) { - ACCESS_ONCE(rcu_cpu_stall_timeout) = 3; - till_stall_check = 3; - } else if (till_stall_check > 300) { - ACCESS_ONCE(rcu_cpu_stall_timeout) = 300; - till_stall_check = 300; - } - return till_stall_check * HZ + RCU_STALL_DELAY_DELTA; + rcu_kick_nohz_cpu(rdp->cpu); + + return 0; } static void record_gp_stall_check_time(struct rcu_state *rsp) { rsp->gp_start = jiffies; - rsp->jiffies_stall = jiffies + jiffies_till_stall_check(); + rsp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check(); } /* @@ -857,7 +858,7 @@ static void print_other_cpu_stall(struct rcu_state *rsp) raw_spin_unlock_irqrestore(&rnp->lock, flags); return; } - rsp->jiffies_stall = jiffies + 3 * jiffies_till_stall_check() + 3; + rsp->jiffies_stall = jiffies + 3 * rcu_jiffies_till_stall_check() + 3; raw_spin_unlock_irqrestore(&rnp->lock, flags); /* @@ -935,7 +936,7 @@ static void print_cpu_stall(struct rcu_state *rsp) raw_spin_lock_irqsave(&rnp->lock, flags); if (ULONG_CMP_GE(jiffies, rsp->jiffies_stall)) rsp->jiffies_stall = jiffies + - 3 * jiffies_till_stall_check() + 3; + 3 * rcu_jiffies_till_stall_check() + 3; raw_spin_unlock_irqrestore(&rnp->lock, flags); set_need_resched(); /* kick ourselves to get things going. */ @@ -966,12 +967,6 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) } } -static int rcu_panic(struct notifier_block *this, unsigned long ev, void *ptr) -{ - rcu_cpu_stall_suppress = 1; - return NOTIFY_DONE; -} - /** * rcu_cpu_stall_reset - prevent further stall warnings in current grace period * @@ -989,15 +984,6 @@ void rcu_cpu_stall_reset(void) rsp->jiffies_stall = jiffies + ULONG_MAX / 2; } -static struct notifier_block rcu_panic_block = { - .notifier_call = rcu_panic, -}; - -static void __init check_cpu_stall_init(void) -{ - atomic_notifier_chain_register(&panic_notifier_list, &rcu_panic_block); -} - /* * Update CPU-local rcu_data state to record the newly noticed grace period. * This is used both when we started the grace period and when we notice @@ -1064,10 +1050,266 @@ static void init_callback_list(struct rcu_data *rdp) { int i; + if (init_nocb_callback_list(rdp)) + return; rdp->nxtlist = NULL; for (i = 0; i < RCU_NEXT_SIZE; i++) rdp->nxttail[i] = &rdp->nxtlist; - init_nocb_callback_list(rdp); +} + +/* + * Determine the value that ->completed will have at the end of the + * next subsequent grace period. This is used to tag callbacks so that + * a CPU can invoke callbacks in a timely fashion even if that CPU has + * been dyntick-idle for an extended period with callbacks under the + * influence of RCU_FAST_NO_HZ. + * + * The caller must hold rnp->lock with interrupts disabled. + */ +static unsigned long rcu_cbs_completed(struct rcu_state *rsp, + struct rcu_node *rnp) +{ + /* + * If RCU is idle, we just wait for the next grace period. + * But we can only be sure that RCU is idle if we are looking + * at the root rcu_node structure -- otherwise, a new grace + * period might have started, but just not yet gotten around + * to initializing the current non-root rcu_node structure. + */ + if (rcu_get_root(rsp) == rnp && rnp->gpnum == rnp->completed) + return rnp->completed + 1; + + /* + * Otherwise, wait for a possible partial grace period and + * then the subsequent full grace period. + */ + return rnp->completed + 2; +} + +/* + * Trace-event helper function for rcu_start_future_gp() and + * rcu_nocb_wait_gp(). + */ +static void trace_rcu_future_gp(struct rcu_node *rnp, struct rcu_data *rdp, + unsigned long c, char *s) +{ + trace_rcu_future_grace_period(rdp->rsp->name, rnp->gpnum, + rnp->completed, c, rnp->level, + rnp->grplo, rnp->grphi, s); +} + +/* + * Start some future grace period, as needed to handle newly arrived + * callbacks. The required future grace periods are recorded in each + * rcu_node structure's ->need_future_gp field. + * + * The caller must hold the specified rcu_node structure's ->lock. + */ +static unsigned long __maybe_unused +rcu_start_future_gp(struct rcu_node *rnp, struct rcu_data *rdp) +{ + unsigned long c; + int i; + struct rcu_node *rnp_root = rcu_get_root(rdp->rsp); + + /* + * Pick up grace-period number for new callbacks. If this + * grace period is already marked as needed, return to the caller. + */ + c = rcu_cbs_completed(rdp->rsp, rnp); + trace_rcu_future_gp(rnp, rdp, c, "Startleaf"); + if (rnp->need_future_gp[c & 0x1]) { + trace_rcu_future_gp(rnp, rdp, c, "Prestartleaf"); + return c; + } + + /* + * If either this rcu_node structure or the root rcu_node structure + * believe that a grace period is in progress, then we must wait + * for the one following, which is in "c". Because our request + * will be noticed at the end of the current grace period, we don't + * need to explicitly start one. + */ + if (rnp->gpnum != rnp->completed || + ACCESS_ONCE(rnp->gpnum) != ACCESS_ONCE(rnp->completed)) { + rnp->need_future_gp[c & 0x1]++; + trace_rcu_future_gp(rnp, rdp, c, "Startedleaf"); + return c; + } + + /* + * There might be no grace period in progress. If we don't already + * hold it, acquire the root rcu_node structure's lock in order to + * start one (if needed). + */ + if (rnp != rnp_root) + raw_spin_lock(&rnp_root->lock); + + /* + * Get a new grace-period number. If there really is no grace + * period in progress, it will be smaller than the one we obtained + * earlier. Adjust callbacks as needed. Note that even no-CBs + * CPUs have a ->nxtcompleted[] array, so no no-CBs checks needed. + */ + c = rcu_cbs_completed(rdp->rsp, rnp_root); + for (i = RCU_DONE_TAIL; i < RCU_NEXT_TAIL; i++) + if (ULONG_CMP_LT(c, rdp->nxtcompleted[i])) + rdp->nxtcompleted[i] = c; + + /* + * If the needed for the required grace period is already + * recorded, trace and leave. + */ + if (rnp_root->need_future_gp[c & 0x1]) { + trace_rcu_future_gp(rnp, rdp, c, "Prestartedroot"); + goto unlock_out; + } + + /* Record the need for the future grace period. */ + rnp_root->need_future_gp[c & 0x1]++; + + /* If a grace period is not already in progress, start one. */ + if (rnp_root->gpnum != rnp_root->completed) { + trace_rcu_future_gp(rnp, rdp, c, "Startedleafroot"); + } else { + trace_rcu_future_gp(rnp, rdp, c, "Startedroot"); + rcu_start_gp_advanced(rdp->rsp, rnp_root, rdp); + } +unlock_out: + if (rnp != rnp_root) + raw_spin_unlock(&rnp_root->lock); + return c; +} + +/* + * Clean up any old requests for the just-ended grace period. Also return + * whether any additional grace periods have been requested. Also invoke + * rcu_nocb_gp_cleanup() in order to wake up any no-callbacks kthreads + * waiting for this grace period to complete. + */ +static int rcu_future_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp) +{ + int c = rnp->completed; + int needmore; + struct rcu_data *rdp = this_cpu_ptr(rsp->rda); + + rcu_nocb_gp_cleanup(rsp, rnp); + rnp->need_future_gp[c & 0x1] = 0; + needmore = rnp->need_future_gp[(c + 1) & 0x1]; + trace_rcu_future_gp(rnp, rdp, c, needmore ? "CleanupMore" : "Cleanup"); + return needmore; +} + +/* + * If there is room, assign a ->completed number to any callbacks on + * this CPU that have not already been assigned. Also accelerate any + * callbacks that were previously assigned a ->completed number that has + * since proven to be too conservative, which can happen if callbacks get + * assigned a ->completed number while RCU is idle, but with reference to + * a non-root rcu_node structure. This function is idempotent, so it does + * not hurt to call it repeatedly. + * + * The caller must hold rnp->lock with interrupts disabled. + */ +static void rcu_accelerate_cbs(struct rcu_state *rsp, struct rcu_node *rnp, + struct rcu_data *rdp) +{ + unsigned long c; + int i; + + /* If the CPU has no callbacks, nothing to do. */ + if (!rdp->nxttail[RCU_NEXT_TAIL] || !*rdp->nxttail[RCU_DONE_TAIL]) + return; + + /* + * Starting from the sublist containing the callbacks most + * recently assigned a ->completed number and working down, find the + * first sublist that is not assignable to an upcoming grace period. + * Such a sublist has something in it (first two tests) and has + * a ->completed number assigned that will complete sooner than + * the ->completed number for newly arrived callbacks (last test). + * + * The key point is that any later sublist can be assigned the + * same ->completed number as the newly arrived callbacks, which + * means that the callbacks in any of these later sublist can be + * grouped into a single sublist, whether or not they have already + * been assigned a ->completed number. + */ + c = rcu_cbs_completed(rsp, rnp); + for (i = RCU_NEXT_TAIL - 1; i > RCU_DONE_TAIL; i--) + if (rdp->nxttail[i] != rdp->nxttail[i - 1] && + !ULONG_CMP_GE(rdp->nxtcompleted[i], c)) + break; + + /* + * If there are no sublist for unassigned callbacks, leave. + * At the same time, advance "i" one sublist, so that "i" will + * index into the sublist where all the remaining callbacks should + * be grouped into. + */ + if (++i >= RCU_NEXT_TAIL) + return; + + /* + * Assign all subsequent callbacks' ->completed number to the next + * full grace period and group them all in the sublist initially + * indexed by "i". + */ + for (; i <= RCU_NEXT_TAIL; i++) { + rdp->nxttail[i] = rdp->nxttail[RCU_NEXT_TAIL]; + rdp->nxtcompleted[i] = c; + } + /* Record any needed additional grace periods. */ + rcu_start_future_gp(rnp, rdp); + + /* Trace depending on how much we were able to accelerate. */ + if (!*rdp->nxttail[RCU_WAIT_TAIL]) + trace_rcu_grace_period(rsp->name, rdp->gpnum, "AccWaitCB"); + else + trace_rcu_grace_period(rsp->name, rdp->gpnum, "AccReadyCB"); +} + +/* + * Move any callbacks whose grace period has completed to the + * RCU_DONE_TAIL sublist, then compact the remaining sublists and + * assign ->completed numbers to any callbacks in the RCU_NEXT_TAIL + * sublist. This function is idempotent, so it does not hurt to + * invoke it repeatedly. As long as it is not invoked -too- often... + * + * The caller must hold rnp->lock with interrupts disabled. + */ +static void rcu_advance_cbs(struct rcu_state *rsp, struct rcu_node *rnp, + struct rcu_data *rdp) +{ + int i, j; + + /* If the CPU has no callbacks, nothing to do. */ + if (!rdp->nxttail[RCU_NEXT_TAIL] || !*rdp->nxttail[RCU_DONE_TAIL]) + return; + + /* + * Find all callbacks whose ->completed numbers indicate that they + * are ready to invoke, and put them into the RCU_DONE_TAIL sublist. + */ + for (i = RCU_WAIT_TAIL; i < RCU_NEXT_TAIL; i++) { + if (ULONG_CMP_LT(rnp->completed, rdp->nxtcompleted[i])) + break; + rdp->nxttail[RCU_DONE_TAIL] = rdp->nxttail[i]; + } + /* Clean up any sublist tail pointers that were misordered above. */ + for (j = RCU_WAIT_TAIL; j < i; j++) + rdp->nxttail[j] = rdp->nxttail[RCU_DONE_TAIL]; + + /* Copy down callbacks to fill in empty sublists. */ + for (j = RCU_WAIT_TAIL; i < RCU_NEXT_TAIL; i++, j++) { + if (rdp->nxttail[j] == rdp->nxttail[RCU_NEXT_TAIL]) + break; + rdp->nxttail[j] = rdp->nxttail[i]; + rdp->nxtcompleted[j] = rdp->nxtcompleted[i]; + } + + /* Classify any remaining callbacks. */ + rcu_accelerate_cbs(rsp, rnp, rdp); } /* @@ -1080,12 +1322,15 @@ static void __rcu_process_gp_end(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp) { /* Did another grace period end? */ - if (rdp->completed != rnp->completed) { + if (rdp->completed == rnp->completed) { + + /* No, so just accelerate recent callbacks. */ + rcu_accelerate_cbs(rsp, rnp, rdp); + + } else { - /* Advance callbacks. No harm if list empty. */ - rdp->nxttail[RCU_DONE_TAIL] = rdp->nxttail[RCU_WAIT_TAIL]; - rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_READY_TAIL]; - rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL]; + /* Advance callbacks. */ + rcu_advance_cbs(rsp, rnp, rdp); /* Remember that we saw this grace-period completion. */ rdp->completed = rnp->completed; @@ -1195,9 +1440,9 @@ static int rcu_gp_init(struct rcu_state *rsp) rdp = this_cpu_ptr(rsp->rda); rcu_preempt_check_blocked_tasks(rnp); rnp->qsmask = rnp->qsmaskinit; - rnp->gpnum = rsp->gpnum; + ACCESS_ONCE(rnp->gpnum) = rsp->gpnum; WARN_ON_ONCE(rnp->completed != rsp->completed); - rnp->completed = rsp->completed; + ACCESS_ONCE(rnp->completed) = rsp->completed; if (rnp == rdp->mynode) rcu_start_gp_per_cpu(rsp, rnp, rdp); rcu_preempt_boost_start_gp(rnp); @@ -1206,7 +1451,8 @@ static int rcu_gp_init(struct rcu_state *rsp) rnp->grphi, rnp->qsmask); raw_spin_unlock_irq(&rnp->lock); #ifdef CONFIG_PROVE_RCU_DELAY - if ((random32() % (rcu_num_nodes * 8)) == 0) + if ((prandom_u32() % (rcu_num_nodes * 8)) == 0 && + system_state == SYSTEM_RUNNING) schedule_timeout_uninterruptible(2); #endif /* #ifdef CONFIG_PROVE_RCU_DELAY */ cond_resched(); @@ -1248,6 +1494,7 @@ int rcu_gp_fqs(struct rcu_state *rsp, int fqs_state_in) static void rcu_gp_cleanup(struct rcu_state *rsp) { unsigned long gp_duration; + int nocb = 0; struct rcu_data *rdp; struct rcu_node *rnp = rcu_get_root(rsp); @@ -1277,17 +1524,23 @@ static void rcu_gp_cleanup(struct rcu_state *rsp) */ rcu_for_each_node_breadth_first(rsp, rnp) { raw_spin_lock_irq(&rnp->lock); - rnp->completed = rsp->gpnum; + ACCESS_ONCE(rnp->completed) = rsp->gpnum; + rdp = this_cpu_ptr(rsp->rda); + if (rnp == rdp->mynode) + __rcu_process_gp_end(rsp, rnp, rdp); + nocb += rcu_future_gp_cleanup(rsp, rnp); raw_spin_unlock_irq(&rnp->lock); cond_resched(); } rnp = rcu_get_root(rsp); raw_spin_lock_irq(&rnp->lock); + rcu_nocb_gp_set(rnp, nocb); rsp->completed = rsp->gpnum; /* Declare grace period done. */ trace_rcu_grace_period(rsp->name, rsp->completed, "end"); rsp->fqs_state = RCU_GP_IDLE; rdp = this_cpu_ptr(rsp->rda); + rcu_advance_cbs(rsp, rnp, rdp); /* Reduce false positives below. */ if (cpu_needs_another_gp(rsp, rdp)) rsp->gp_flags = 1; raw_spin_unlock_irq(&rnp->lock); @@ -1363,64 +1616,62 @@ static int __noreturn rcu_gp_kthread(void *arg) /* * Start a new RCU grace period if warranted, re-initializing the hierarchy * in preparation for detecting the next grace period. The caller must hold - * the root node's ->lock, which is released before return. Hard irqs must - * be disabled. + * the root node's ->lock and hard irqs must be disabled. * * Note that it is legal for a dying CPU (which is marked as offline) to * invoke this function. This can happen when the dying CPU reports its * quiescent state. */ static void -rcu_start_gp(struct rcu_state *rsp, unsigned long flags) - __releases(rcu_get_root(rsp)->lock) +rcu_start_gp_advanced(struct rcu_state *rsp, struct rcu_node *rnp, + struct rcu_data *rdp) { - struct rcu_data *rdp = this_cpu_ptr(rsp->rda); - struct rcu_node *rnp = rcu_get_root(rsp); - - if (!rsp->gp_kthread || - !cpu_needs_another_gp(rsp, rdp)) { + if (!rsp->gp_kthread || !cpu_needs_another_gp(rsp, rdp)) { /* * Either we have not yet spawned the grace-period * task, this CPU does not need another grace period, * or a grace period is already in progress. * Either way, don't start a new grace period. */ - raw_spin_unlock_irqrestore(&rnp->lock, flags); return; } - - /* - * Because there is no grace period in progress right now, - * any callbacks we have up to this point will be satisfied - * by the next grace period. So promote all callbacks to be - * handled after the end of the next grace period. If the - * CPU is not yet aware of the end of the previous grace period, - * we need to allow for the callback advancement that will - * occur when it does become aware. Deadlock prevents us from - * making it aware at this point: We cannot acquire a leaf - * rcu_node ->lock while holding the root rcu_node ->lock. - */ - rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL]; - if (rdp->completed == rsp->completed) - rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL]; - rsp->gp_flags = RCU_GP_FLAG_INIT; - raw_spin_unlock(&rnp->lock); /* Interrupts remain disabled. */ - - /* Ensure that CPU is aware of completion of last grace period. */ - rcu_process_gp_end(rsp, rdp); - local_irq_restore(flags); /* Wake up rcu_gp_kthread() to start the grace period. */ wake_up(&rsp->gp_wq); } /* + * Similar to rcu_start_gp_advanced(), but also advance the calling CPU's + * callbacks. Note that rcu_start_gp_advanced() cannot do this because it + * is invoked indirectly from rcu_advance_cbs(), which would result in + * endless recursion -- or would do so if it wasn't for the self-deadlock + * that is encountered beforehand. + */ +static void +rcu_start_gp(struct rcu_state *rsp) +{ + struct rcu_data *rdp = this_cpu_ptr(rsp->rda); + struct rcu_node *rnp = rcu_get_root(rsp); + + /* + * If there is no grace period in progress right now, any + * callbacks we have up to this point will be satisfied by the + * next grace period. Also, advancing the callbacks reduces the + * probability of false positives from cpu_needs_another_gp() + * resulting in pointless grace periods. So, advance callbacks + * then start the grace period! + */ + rcu_advance_cbs(rsp, rnp, rdp); + rcu_start_gp_advanced(rsp, rnp, rdp); +} + +/* * Report a full set of quiescent states to the specified rcu_state * data structure. This involves cleaning up after the prior grace * period and letting rcu_start_gp() start up the next grace period - * if one is needed. Note that the caller must hold rnp->lock, as - * required by rcu_start_gp(), which will release it. + * if one is needed. Note that the caller must hold rnp->lock, which + * is released before return. */ static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags) __releases(rcu_get_root(rsp)->lock) @@ -1527,7 +1778,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp) * This GP can't end until cpu checks in, so all of our * callbacks can be processed during the next GP. */ - rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL]; + rcu_accelerate_cbs(rsp, rnp, rdp); rcu_report_qs_rnp(mask, rsp, rnp, flags); /* rlses rnp->lock */ } @@ -1579,7 +1830,7 @@ rcu_send_cbs_to_orphanage(int cpu, struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp) { /* No-CBs CPUs do not have orphanable callbacks. */ - if (is_nocb_cpu(rdp->cpu)) + if (rcu_is_nocb_cpu(rdp->cpu)) return; /* @@ -1779,7 +2030,7 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp) long bl, count, count_lazy; int i; - /* If no callbacks are ready, just return.*/ + /* If no callbacks are ready, just return. */ if (!cpu_has_callbacks_ready_to_invoke(rdp)) { trace_rcu_batch_start(rsp->name, rdp->qlen_lazy, rdp->qlen, 0); trace_rcu_batch_end(rsp->name, 0, !!ACCESS_ONCE(rdp->nxtlist), @@ -2008,19 +2259,20 @@ __rcu_process_callbacks(struct rcu_state *rsp) WARN_ON_ONCE(rdp->beenonline == 0); - /* - * Advance callbacks in response to end of earlier grace - * period that some other CPU ended. - */ + /* Handle the end of a grace period that some other CPU ended. */ rcu_process_gp_end(rsp, rdp); /* Update RCU state based on any recent quiescent states. */ rcu_check_quiescent_state(rsp, rdp); /* Does this CPU require a not-yet-started grace period? */ + local_irq_save(flags); if (cpu_needs_another_gp(rsp, rdp)) { - raw_spin_lock_irqsave(&rcu_get_root(rsp)->lock, flags); - rcu_start_gp(rsp, flags); /* releases above lock */ + raw_spin_lock(&rcu_get_root(rsp)->lock); /* irqs disabled. */ + rcu_start_gp(rsp); + raw_spin_unlock_irqrestore(&rcu_get_root(rsp)->lock, flags); + } else { + local_irq_restore(flags); } /* If there are callbacks ready, invoke them. */ @@ -2063,7 +2315,8 @@ static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp) static void invoke_rcu_core(void) { - raise_softirq(RCU_SOFTIRQ); + if (cpu_online(smp_processor_id())) + raise_softirq(RCU_SOFTIRQ); } /* @@ -2098,11 +2351,11 @@ static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp, /* Start a new grace period if one not already started. */ if (!rcu_gp_in_progress(rsp)) { - unsigned long nestflag; struct rcu_node *rnp_root = rcu_get_root(rsp); - raw_spin_lock_irqsave(&rnp_root->lock, nestflag); - rcu_start_gp(rsp, nestflag); /* rlses rnp_root->lock */ + raw_spin_lock(&rnp_root->lock); + rcu_start_gp(rsp); + raw_spin_unlock(&rnp_root->lock); } else { /* Give the grace period a kick. */ rdp->blimit = LONG_MAX; @@ -2522,19 +2775,27 @@ static int rcu_pending(int cpu) } /* - * Check to see if any future RCU-related work will need to be done - * by the current CPU, even if none need be done immediately, returning - * 1 if so. + * Return true if the specified CPU has any callback. If all_lazy is + * non-NULL, store an indication of whether all callbacks are lazy. + * (If there are no callbacks, all of them are deemed to be lazy.) */ -static int rcu_cpu_has_callbacks(int cpu) +static int rcu_cpu_has_callbacks(int cpu, bool *all_lazy) { + bool al = true; + bool hc = false; + struct rcu_data *rdp; struct rcu_state *rsp; - /* RCU callbacks either ready or pending? */ - for_each_rcu_flavor(rsp) - if (per_cpu_ptr(rsp->rda, cpu)->nxtlist) - return 1; - return 0; + for_each_rcu_flavor(rsp) { + rdp = per_cpu_ptr(rsp->rda, cpu); + if (rdp->qlen != rdp->qlen_lazy) + al = false; + if (rdp->nxtlist) + hc = true; + } + if (all_lazy) + *all_lazy = al; + return hc; } /* @@ -2641,10 +2902,10 @@ static void _rcu_barrier(struct rcu_state *rsp) * corresponding CPU's preceding callbacks have been invoked. */ for_each_possible_cpu(cpu) { - if (!cpu_online(cpu) && !is_nocb_cpu(cpu)) + if (!cpu_online(cpu) && !rcu_is_nocb_cpu(cpu)) continue; rdp = per_cpu_ptr(rsp->rda, cpu); - if (is_nocb_cpu(cpu)) { + if (rcu_is_nocb_cpu(cpu)) { _rcu_barrier_trace(rsp, "OnlineNoCB", cpu, rsp->n_barrier_done); atomic_inc(&rsp->barrier_cpu_count); @@ -2719,9 +2980,6 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) rdp->dynticks = &per_cpu(rcu_dynticks, cpu); WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != DYNTICK_TASK_EXIT_IDLE); WARN_ON_ONCE(atomic_read(&rdp->dynticks->dynticks) != 1); -#ifdef CONFIG_RCU_USER_QS - WARN_ON_ONCE(rdp->dynticks->in_user); -#endif rdp->cpu = cpu; rdp->rsp = rsp; rcu_boot_init_nocb_percpu_data(rdp); @@ -2756,7 +3014,6 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible) rdp->dynticks->dynticks_nesting = DYNTICK_TASK_EXIT_IDLE; atomic_set(&rdp->dynticks->dynticks, (atomic_read(&rdp->dynticks->dynticks) & ~0x1) + 1); - rcu_prepare_for_idle_init(cpu); raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ /* Add CPU to rcu_node bitmasks. */ @@ -2806,7 +3063,6 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, cpu); struct rcu_node *rnp = rdp->mynode; struct rcu_state *rsp; - int ret = NOTIFY_OK; trace_rcu_utilization("Start CPU hotplug"); switch (action) { @@ -2820,21 +3076,12 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, rcu_boost_kthread_setaffinity(rnp, -1); break; case CPU_DOWN_PREPARE: - if (nocb_cpu_expendable(cpu)) - rcu_boost_kthread_setaffinity(rnp, cpu); - else - ret = NOTIFY_BAD; + rcu_boost_kthread_setaffinity(rnp, cpu); break; case CPU_DYING: case CPU_DYING_FROZEN: - /* - * The whole machine is "stopped" except this CPU, so we can - * touch any data without introducing corruption. We send the - * dying CPU's callbacks to an arbitrarily chosen online CPU. - */ for_each_rcu_flavor(rsp) rcu_cleanup_dying_cpu(rsp); - rcu_cleanup_after_idle(cpu); break; case CPU_DEAD: case CPU_DEAD_FROZEN: @@ -2847,7 +3094,7 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, break; } trace_rcu_utilization("End CPU hotplug"); - return ret; + return NOTIFY_OK; } /* @@ -2938,6 +3185,10 @@ static void __init rcu_init_one(struct rcu_state *rsp, BUILD_BUG_ON(MAX_RCU_LVLS > ARRAY_SIZE(buf)); /* Fix buf[] init! */ + /* Silence gcc 4.8 warning about array index out of range. */ + if (rcu_num_lvls > RCU_NUM_LVLS) + panic("rcu_init_one: rcu_num_lvls overflow"); + /* Initialize the level-tracking arrays. */ for (i = 0; i < rcu_num_lvls; i++) @@ -2978,6 +3229,7 @@ static void __init rcu_init_one(struct rcu_state *rsp, } rnp->level = i; INIT_LIST_HEAD(&rnp->blkd_tasks); + rcu_init_one_nocb(rnp); } } @@ -3063,8 +3315,7 @@ void __init rcu_init(void) rcu_init_one(&rcu_sched_state, &rcu_sched_data); rcu_init_one(&rcu_bh_state, &rcu_bh_data); __rcu_init_preempt(); - rcu_init_nocb(); - open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); + open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); /* * We don't need protection against CPU-hotplug here because @@ -3074,7 +3325,6 @@ void __init rcu_init(void) cpu_notifier(rcu_cpu_notify, 0); for_each_online_cpu(cpu) rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu); - check_cpu_stall_init(); } #include "rcutree_plugin.h" diff --git a/kernel/rcutree.h b/kernel/rcutree.h index 4b69291b093d..da77a8f57ff9 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -88,24 +88,15 @@ struct rcu_dynticks { int dynticks_nmi_nesting; /* Track NMI nesting level. */ atomic_t dynticks; /* Even value for idle, else odd. */ #ifdef CONFIG_RCU_FAST_NO_HZ - int dyntick_drain; /* Prepare-for-idle state variable. */ - unsigned long dyntick_holdoff; - /* No retries for the jiffy of failure. */ - struct timer_list idle_gp_timer; - /* Wake up CPU sleeping with callbacks. */ - unsigned long idle_gp_timer_expires; - /* When to wake up CPU (for repost). */ - bool idle_first_pass; /* First pass of attempt to go idle? */ + bool all_lazy; /* Are all CPU's CBs lazy? */ unsigned long nonlazy_posted; /* # times non-lazy CBs posted to CPU. */ unsigned long nonlazy_posted_snap; /* idle-period nonlazy_posted snapshot. */ + unsigned long last_accelerate; + /* Last jiffy CBs were accelerated. */ int tick_nohz_enabled_snap; /* Previously seen value from sysfs. */ #endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */ -#ifdef CONFIG_RCU_USER_QS - bool ignore_user_qs; /* Treat userspace as extended QS or not */ - bool in_user; /* Is the CPU in userland from RCU POV? */ -#endif }; /* RCU's kthread states for tracing. */ @@ -138,9 +129,6 @@ struct rcu_node { /* elements that need to drain to allow the */ /* current expedited grace period to */ /* complete (only for TREE_PREEMPT_RCU). */ - atomic_t wakemask; /* CPUs whose kthread needs to be awakened. */ - /* Since this has meaning only for leaf */ - /* rcu_node structures, 32 bits suffices. */ unsigned long qsmaskinit; /* Per-GP initial value for qsmask & expmask. */ unsigned long grpmask; /* Mask to apply to parent qsmask. */ @@ -200,6 +188,12 @@ struct rcu_node { /* Refused to boost: not sure why, though. */ /* This can happen due to race conditions. */ #endif /* #ifdef CONFIG_RCU_BOOST */ +#ifdef CONFIG_RCU_NOCB_CPU + wait_queue_head_t nocb_gp_wq[2]; + /* Place for rcu_nocb_kthread() to wait GP. */ +#endif /* #ifdef CONFIG_RCU_NOCB_CPU */ + int need_future_gp[2]; + /* Counts of upcoming no-CB GP requests. */ raw_spinlock_t fqslock ____cacheline_internodealigned_in_smp; } ____cacheline_internodealigned_in_smp; @@ -282,6 +276,8 @@ struct rcu_data { */ struct rcu_head *nxtlist; struct rcu_head **nxttail[RCU_NEXT_SIZE]; + unsigned long nxtcompleted[RCU_NEXT_SIZE]; + /* grace periods for sublists. */ long qlen_lazy; /* # of lazy queued callbacks */ long qlen; /* # of queued callbacks, incl lazy */ long qlen_last_fqs_check; @@ -330,6 +326,11 @@ struct rcu_data { struct task_struct *nocb_kthread; #endif /* #ifdef CONFIG_RCU_NOCB_CPU */ + /* 8) RCU CPU stall data. */ +#ifdef CONFIG_RCU_CPU_STALL_INFO + unsigned int softirq_snap; /* Snapshot of softirq activity. */ +#endif /* #ifdef CONFIG_RCU_CPU_STALL_INFO */ + int cpu; struct rcu_state *rsp; }; @@ -343,11 +344,6 @@ struct rcu_data { #define RCU_JIFFIES_TILL_FORCE_QS 3 /* for rsp->jiffies_force_qs */ -#ifdef CONFIG_PROVE_RCU -#define RCU_STALL_DELAY_DELTA (5 * HZ) -#else -#define RCU_STALL_DELAY_DELTA 0 -#endif #define RCU_STALL_RAT_DELAY 2 /* Allow other CPUs time */ /* to take at least one */ /* scheduling clock irq */ @@ -382,12 +378,6 @@ struct rcu_state { struct rcu_data __percpu *rda; /* pointer of percu rcu_data. */ void (*call)(struct rcu_head *head, /* call_rcu() flavor. */ void (*func)(struct rcu_head *head)); -#ifdef CONFIG_RCU_NOCB_CPU - void (*call_remote)(struct rcu_head *head, - void (*func)(struct rcu_head *head)); - /* call_rcu() flavor, but for */ - /* placing on remote CPU. */ -#endif /* #ifdef CONFIG_RCU_NOCB_CPU */ /* The following fields are guarded by the root rcu_node's lock. */ @@ -450,6 +440,7 @@ struct rcu_state { unsigned long gp_max; /* Maximum GP duration in */ /* jiffies. */ char *name; /* Name of structure. */ + char abbr; /* Abbreviated name. */ struct list_head flavors; /* List of RCU flavors. */ }; @@ -527,7 +518,6 @@ static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp, struct rcu_node *rnp); #endif /* #ifdef CONFIG_RCU_BOOST */ static void __cpuinit rcu_prepare_kthreads(int cpu); -static void rcu_prepare_for_idle_init(int cpu); static void rcu_cleanup_after_idle(int cpu); static void rcu_prepare_for_idle(int cpu); static void rcu_idle_count_callbacks_posted(void); @@ -536,16 +526,18 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu); static void print_cpu_stall_info_end(void); static void zero_cpu_stall_ticks(struct rcu_data *rdp); static void increment_cpu_stall_ticks(void); -static bool is_nocb_cpu(int cpu); +static int rcu_nocb_needs_gp(struct rcu_state *rsp); +static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq); +static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp); +static void rcu_init_one_nocb(struct rcu_node *rnp); static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp, bool lazy); static bool rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp, struct rcu_data *rdp); -static bool nocb_cpu_expendable(int cpu); static void rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp); static void rcu_spawn_nocb_kthreads(struct rcu_state *rsp); -static void init_nocb_callback_list(struct rcu_data *rdp); -static void __init rcu_init_nocb(void); +static void rcu_kick_nohz_cpu(int cpu); +static bool init_nocb_callback_list(struct rcu_data *rdp); #endif /* #ifndef RCU_TREE_NONCORE */ diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index c1cc7e17ff9d..170814dc418f 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -28,6 +28,7 @@ #include <linux/gfp.h> #include <linux/oom.h> #include <linux/smpboot.h> +#include <linux/tick.h> #define RCU_KTHREAD_PRIO 1 @@ -85,11 +86,21 @@ static void __init rcu_bootup_announce_oddness(void) if (nr_cpu_ids != NR_CPUS) printk(KERN_INFO "\tRCU restricting CPUs from NR_CPUS=%d to nr_cpu_ids=%d.\n", NR_CPUS, nr_cpu_ids); #ifdef CONFIG_RCU_NOCB_CPU +#ifndef CONFIG_RCU_NOCB_CPU_NONE + if (!have_rcu_nocb_mask) { + alloc_bootmem_cpumask_var(&rcu_nocb_mask); + have_rcu_nocb_mask = true; + } +#ifdef CONFIG_RCU_NOCB_CPU_ZERO + pr_info("\tExperimental no-CBs CPU 0\n"); + cpumask_set_cpu(0, rcu_nocb_mask); +#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ZERO */ +#ifdef CONFIG_RCU_NOCB_CPU_ALL + pr_info("\tExperimental no-CBs for all CPUs\n"); + cpumask_setall(rcu_nocb_mask); +#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ALL */ +#endif /* #ifndef CONFIG_RCU_NOCB_CPU_NONE */ if (have_rcu_nocb_mask) { - if (cpumask_test_cpu(0, rcu_nocb_mask)) { - cpumask_clear_cpu(0, rcu_nocb_mask); - pr_info("\tCPU 0: illegal no-CBs CPU (cleared).\n"); - } cpulist_scnprintf(nocb_buf, sizeof(nocb_buf), rcu_nocb_mask); pr_info("\tExperimental no-CBs CPUs: %s.\n", nocb_buf); if (rcu_nocb_poll) @@ -101,7 +112,7 @@ static void __init rcu_bootup_announce_oddness(void) #ifdef CONFIG_TREE_PREEMPT_RCU struct rcu_state rcu_preempt_state = - RCU_STATE_INITIALIZER(rcu_preempt, call_rcu); + RCU_STATE_INITIALIZER(rcu_preempt, 'p', call_rcu); DEFINE_PER_CPU(struct rcu_data, rcu_preempt_data); static struct rcu_state *rcu_state = &rcu_preempt_state; @@ -1533,14 +1544,7 @@ static void __cpuinit rcu_prepare_kthreads(int cpu) int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) { *delta_jiffies = ULONG_MAX; - return rcu_cpu_has_callbacks(cpu); -} - -/* - * Because we do not have RCU_FAST_NO_HZ, don't bother initializing for it. - */ -static void rcu_prepare_for_idle_init(int cpu) -{ + return rcu_cpu_has_callbacks(cpu, NULL); } /* @@ -1577,16 +1581,6 @@ static void rcu_idle_count_callbacks_posted(void) * * The following three proprocessor symbols control this state machine: * - * RCU_IDLE_FLUSHES gives the maximum number of times that we will attempt - * to satisfy RCU. Beyond this point, it is better to incur a periodic - * scheduling-clock interrupt than to loop through the state machine - * at full power. - * RCU_IDLE_OPT_FLUSHES gives the number of RCU_IDLE_FLUSHES that are - * optional if RCU does not need anything immediately from this - * CPU, even if this CPU still has RCU callbacks queued. The first - * times through the state machine are mandatory: we need to give - * the state machine a chance to communicate a quiescent state - * to the RCU core. * RCU_IDLE_GP_DELAY gives the number of jiffies that a CPU is permitted * to sleep in dyntick-idle mode with RCU callbacks pending. This * is sized to be roughly one RCU grace period. Those energy-efficiency @@ -1602,186 +1596,108 @@ static void rcu_idle_count_callbacks_posted(void) * adjustment, they can be converted into kernel config parameters, though * making the state machine smarter might be a better option. */ -#define RCU_IDLE_FLUSHES 5 /* Number of dyntick-idle tries. */ -#define RCU_IDLE_OPT_FLUSHES 3 /* Optional dyntick-idle tries. */ #define RCU_IDLE_GP_DELAY 4 /* Roughly one grace period. */ #define RCU_IDLE_LAZY_GP_DELAY (6 * HZ) /* Roughly six seconds. */ -extern int tick_nohz_enabled; - -/* - * Does the specified flavor of RCU have non-lazy callbacks pending on - * the specified CPU? Both RCU flavor and CPU are specified by the - * rcu_data structure. - */ -static bool __rcu_cpu_has_nonlazy_callbacks(struct rcu_data *rdp) -{ - return rdp->qlen != rdp->qlen_lazy; -} +static int rcu_idle_gp_delay = RCU_IDLE_GP_DELAY; +module_param(rcu_idle_gp_delay, int, 0644); +static int rcu_idle_lazy_gp_delay = RCU_IDLE_LAZY_GP_DELAY; +module_param(rcu_idle_lazy_gp_delay, int, 0644); -#ifdef CONFIG_TREE_PREEMPT_RCU +extern int tick_nohz_enabled; /* - * Are there non-lazy RCU-preempt callbacks? (There cannot be if there - * is no RCU-preempt in the kernel.) + * Try to advance callbacks for all flavors of RCU on the current CPU. + * Afterwards, if there are any callbacks ready for immediate invocation, + * return true. */ -static bool rcu_preempt_cpu_has_nonlazy_callbacks(int cpu) +static bool rcu_try_advance_all_cbs(void) { - struct rcu_data *rdp = &per_cpu(rcu_preempt_data, cpu); - - return __rcu_cpu_has_nonlazy_callbacks(rdp); -} - -#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */ + bool cbs_ready = false; + struct rcu_data *rdp; + struct rcu_node *rnp; + struct rcu_state *rsp; -static bool rcu_preempt_cpu_has_nonlazy_callbacks(int cpu) -{ - return 0; -} + for_each_rcu_flavor(rsp) { + rdp = this_cpu_ptr(rsp->rda); + rnp = rdp->mynode; -#endif /* else #ifdef CONFIG_TREE_PREEMPT_RCU */ + /* + * Don't bother checking unless a grace period has + * completed since we last checked and there are + * callbacks not yet ready to invoke. + */ + if (rdp->completed != rnp->completed && + rdp->nxttail[RCU_DONE_TAIL] != rdp->nxttail[RCU_NEXT_TAIL]) + rcu_process_gp_end(rsp, rdp); -/* - * Does any flavor of RCU have non-lazy callbacks on the specified CPU? - */ -static bool rcu_cpu_has_nonlazy_callbacks(int cpu) -{ - return __rcu_cpu_has_nonlazy_callbacks(&per_cpu(rcu_sched_data, cpu)) || - __rcu_cpu_has_nonlazy_callbacks(&per_cpu(rcu_bh_data, cpu)) || - rcu_preempt_cpu_has_nonlazy_callbacks(cpu); + if (cpu_has_callbacks_ready_to_invoke(rdp)) + cbs_ready = true; + } + return cbs_ready; } /* - * Allow the CPU to enter dyntick-idle mode if either: (1) There are no - * callbacks on this CPU, (2) this CPU has not yet attempted to enter - * dyntick-idle mode, or (3) this CPU is in the process of attempting to - * enter dyntick-idle mode. Otherwise, if we have recently tried and failed - * to enter dyntick-idle mode, we refuse to try to enter it. After all, - * it is better to incur scheduling-clock interrupts than to spin - * continuously for the same time duration! + * Allow the CPU to enter dyntick-idle mode unless it has callbacks ready + * to invoke. If the CPU has callbacks, try to advance them. Tell the + * caller to set the timeout based on whether or not there are non-lazy + * callbacks. * - * The delta_jiffies argument is used to store the time when RCU is - * going to need the CPU again if it still has callbacks. The reason - * for this is that rcu_prepare_for_idle() might need to post a timer, - * but if so, it will do so after tick_nohz_stop_sched_tick() has set - * the wakeup time for this CPU. This means that RCU's timer can be - * delayed until the wakeup time, which defeats the purpose of posting - * a timer. + * The caller must have disabled interrupts. */ -int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) +int rcu_needs_cpu(int cpu, unsigned long *dj) { struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu); - /* Flag a new idle sojourn to the idle-entry state machine. */ - rdtp->idle_first_pass = 1; + /* Snapshot to detect later posting of non-lazy callback. */ + rdtp->nonlazy_posted_snap = rdtp->nonlazy_posted; + /* If no callbacks, RCU doesn't need the CPU. */ - if (!rcu_cpu_has_callbacks(cpu)) { - *delta_jiffies = ULONG_MAX; + if (!rcu_cpu_has_callbacks(cpu, &rdtp->all_lazy)) { + *dj = ULONG_MAX; return 0; } - if (rdtp->dyntick_holdoff == jiffies) { - /* RCU recently tried and failed, so don't try again. */ - *delta_jiffies = 1; + + /* Attempt to advance callbacks. */ + if (rcu_try_advance_all_cbs()) { + /* Some ready to invoke, so initiate later invocation. */ + invoke_rcu_core(); return 1; } - /* Set up for the possibility that RCU will post a timer. */ - if (rcu_cpu_has_nonlazy_callbacks(cpu)) { - *delta_jiffies = round_up(RCU_IDLE_GP_DELAY + jiffies, - RCU_IDLE_GP_DELAY) - jiffies; + rdtp->last_accelerate = jiffies; + + /* Request timer delay depending on laziness, and round. */ + if (rdtp->all_lazy) { + *dj = round_up(rcu_idle_gp_delay + jiffies, + rcu_idle_gp_delay) - jiffies; } else { - *delta_jiffies = jiffies + RCU_IDLE_LAZY_GP_DELAY; - *delta_jiffies = round_jiffies(*delta_jiffies) - jiffies; + *dj = round_jiffies(rcu_idle_lazy_gp_delay + jiffies) - jiffies; } return 0; } /* - * Handler for smp_call_function_single(). The only point of this - * handler is to wake the CPU up, so the handler does only tracing. - */ -void rcu_idle_demigrate(void *unused) -{ - trace_rcu_prep_idle("Demigrate"); -} - -/* - * Timer handler used to force CPU to start pushing its remaining RCU - * callbacks in the case where it entered dyntick-idle mode with callbacks - * pending. The hander doesn't really need to do anything because the - * real work is done upon re-entry to idle, or by the next scheduling-clock - * interrupt should idle not be re-entered. - * - * One special case: the timer gets migrated without awakening the CPU - * on which the timer was scheduled on. In this case, we must wake up - * that CPU. We do so with smp_call_function_single(). - */ -static void rcu_idle_gp_timer_func(unsigned long cpu_in) -{ - int cpu = (int)cpu_in; - - trace_rcu_prep_idle("Timer"); - if (cpu != smp_processor_id()) - smp_call_function_single(cpu, rcu_idle_demigrate, NULL, 0); - else - WARN_ON_ONCE(1); /* Getting here can hang the system... */ -} - -/* - * Initialize the timer used to pull CPUs out of dyntick-idle mode. - */ -static void rcu_prepare_for_idle_init(int cpu) -{ - struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu); - - rdtp->dyntick_holdoff = jiffies - 1; - setup_timer(&rdtp->idle_gp_timer, rcu_idle_gp_timer_func, cpu); - rdtp->idle_gp_timer_expires = jiffies - 1; - rdtp->idle_first_pass = 1; -} - -/* - * Clean up for exit from idle. Because we are exiting from idle, there - * is no longer any point to ->idle_gp_timer, so cancel it. This will - * do nothing if this timer is not active, so just cancel it unconditionally. - */ -static void rcu_cleanup_after_idle(int cpu) -{ - struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu); - - del_timer(&rdtp->idle_gp_timer); - trace_rcu_prep_idle("Cleanup after idle"); - rdtp->tick_nohz_enabled_snap = ACCESS_ONCE(tick_nohz_enabled); -} - -/* - * Check to see if any RCU-related work can be done by the current CPU, - * and if so, schedule a softirq to get it done. This function is part - * of the RCU implementation; it is -not- an exported member of the RCU API. - * - * The idea is for the current CPU to clear out all work required by the - * RCU core for the current grace period, so that this CPU can be permitted - * to enter dyntick-idle mode. In some cases, it will need to be awakened - * at the end of the grace period by whatever CPU ends the grace period. - * This allows CPUs to go dyntick-idle more quickly, and to reduce the - * number of wakeups by a modest integer factor. - * - * Because it is not legal to invoke rcu_process_callbacks() with irqs - * disabled, we do one pass of force_quiescent_state(), then do a - * invoke_rcu_core() to cause rcu_process_callbacks() to be invoked - * later. The ->dyntick_drain field controls the sequencing. + * Prepare a CPU for idle from an RCU perspective. The first major task + * is to sense whether nohz mode has been enabled or disabled via sysfs. + * The second major task is to check to see if a non-lazy callback has + * arrived at a CPU that previously had only lazy callbacks. The third + * major task is to accelerate (that is, assign grace-period numbers to) + * any recently arrived callbacks. * * The caller must have disabled interrupts. */ static void rcu_prepare_for_idle(int cpu) { - struct timer_list *tp; + struct rcu_data *rdp; struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu); + struct rcu_node *rnp; + struct rcu_state *rsp; int tne; /* Handle nohz enablement switches conservatively. */ tne = ACCESS_ONCE(tick_nohz_enabled); if (tne != rdtp->tick_nohz_enabled_snap) { - if (rcu_cpu_has_callbacks(cpu)) + if (rcu_cpu_has_callbacks(cpu, NULL)) invoke_rcu_core(); /* force nohz to see update. */ rdtp->tick_nohz_enabled_snap = tne; return; @@ -1789,125 +1705,56 @@ static void rcu_prepare_for_idle(int cpu) if (!tne) return; - /* Adaptive-tick mode, where usermode execution is idle to RCU. */ - if (!is_idle_task(current)) { - rdtp->dyntick_holdoff = jiffies - 1; - if (rcu_cpu_has_nonlazy_callbacks(cpu)) { - trace_rcu_prep_idle("User dyntick with callbacks"); - rdtp->idle_gp_timer_expires = - round_up(jiffies + RCU_IDLE_GP_DELAY, - RCU_IDLE_GP_DELAY); - } else if (rcu_cpu_has_callbacks(cpu)) { - rdtp->idle_gp_timer_expires = - round_jiffies(jiffies + RCU_IDLE_LAZY_GP_DELAY); - trace_rcu_prep_idle("User dyntick with lazy callbacks"); - } else { - return; - } - tp = &rdtp->idle_gp_timer; - mod_timer_pinned(tp, rdtp->idle_gp_timer_expires); + /* If this is a no-CBs CPU, no callbacks, just return. */ + if (rcu_is_nocb_cpu(cpu)) return; - } /* - * If this is an idle re-entry, for example, due to use of - * RCU_NONIDLE() or the new idle-loop tracing API within the idle - * loop, then don't take any state-machine actions, unless the - * momentary exit from idle queued additional non-lazy callbacks. - * Instead, repost the ->idle_gp_timer if this CPU has callbacks - * pending. + * If a non-lazy callback arrived at a CPU having only lazy + * callbacks, invoke RCU core for the side-effect of recalculating + * idle duration on re-entry to idle. */ - if (!rdtp->idle_first_pass && - (rdtp->nonlazy_posted == rdtp->nonlazy_posted_snap)) { - if (rcu_cpu_has_callbacks(cpu)) { - tp = &rdtp->idle_gp_timer; - mod_timer_pinned(tp, rdtp->idle_gp_timer_expires); - } + if (rdtp->all_lazy && + rdtp->nonlazy_posted != rdtp->nonlazy_posted_snap) { + invoke_rcu_core(); return; } - rdtp->idle_first_pass = 0; - rdtp->nonlazy_posted_snap = rdtp->nonlazy_posted - 1; /* - * If there are no callbacks on this CPU, enter dyntick-idle mode. - * Also reset state to avoid prejudicing later attempts. + * If we have not yet accelerated this jiffy, accelerate all + * callbacks on this CPU. */ - if (!rcu_cpu_has_callbacks(cpu)) { - rdtp->dyntick_holdoff = jiffies - 1; - rdtp->dyntick_drain = 0; - trace_rcu_prep_idle("No callbacks"); + if (rdtp->last_accelerate == jiffies) return; + rdtp->last_accelerate = jiffies; + for_each_rcu_flavor(rsp) { + rdp = per_cpu_ptr(rsp->rda, cpu); + if (!*rdp->nxttail[RCU_DONE_TAIL]) + continue; + rnp = rdp->mynode; + raw_spin_lock(&rnp->lock); /* irqs already disabled. */ + rcu_accelerate_cbs(rsp, rnp, rdp); + raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ } +} - /* - * If in holdoff mode, just return. We will presumably have - * refrained from disabling the scheduling-clock tick. - */ - if (rdtp->dyntick_holdoff == jiffies) { - trace_rcu_prep_idle("In holdoff"); - return; - } +/* + * Clean up for exit from idle. Attempt to advance callbacks based on + * any grace periods that elapsed while the CPU was idle, and if any + * callbacks are now ready to invoke, initiate invocation. + */ +static void rcu_cleanup_after_idle(int cpu) +{ + struct rcu_data *rdp; + struct rcu_state *rsp; - /* Check and update the ->dyntick_drain sequencing. */ - if (rdtp->dyntick_drain <= 0) { - /* First time through, initialize the counter. */ - rdtp->dyntick_drain = RCU_IDLE_FLUSHES; - } else if (rdtp->dyntick_drain <= RCU_IDLE_OPT_FLUSHES && - !rcu_pending(cpu) && - !local_softirq_pending()) { - /* Can we go dyntick-idle despite still having callbacks? */ - rdtp->dyntick_drain = 0; - rdtp->dyntick_holdoff = jiffies; - if (rcu_cpu_has_nonlazy_callbacks(cpu)) { - trace_rcu_prep_idle("Dyntick with callbacks"); - rdtp->idle_gp_timer_expires = - round_up(jiffies + RCU_IDLE_GP_DELAY, - RCU_IDLE_GP_DELAY); - } else { - rdtp->idle_gp_timer_expires = - round_jiffies(jiffies + RCU_IDLE_LAZY_GP_DELAY); - trace_rcu_prep_idle("Dyntick with lazy callbacks"); - } - tp = &rdtp->idle_gp_timer; - mod_timer_pinned(tp, rdtp->idle_gp_timer_expires); - rdtp->nonlazy_posted_snap = rdtp->nonlazy_posted; - return; /* Nothing more to do immediately. */ - } else if (--(rdtp->dyntick_drain) <= 0) { - /* We have hit the limit, so time to give up. */ - rdtp->dyntick_holdoff = jiffies; - trace_rcu_prep_idle("Begin holdoff"); - invoke_rcu_core(); /* Force the CPU out of dyntick-idle. */ + if (rcu_is_nocb_cpu(cpu)) return; - } - - /* - * Do one step of pushing the remaining RCU callbacks through - * the RCU core state machine. - */ -#ifdef CONFIG_TREE_PREEMPT_RCU - if (per_cpu(rcu_preempt_data, cpu).nxtlist) { - rcu_preempt_qs(cpu); - force_quiescent_state(&rcu_preempt_state); - } -#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ - if (per_cpu(rcu_sched_data, cpu).nxtlist) { - rcu_sched_qs(cpu); - force_quiescent_state(&rcu_sched_state); - } - if (per_cpu(rcu_bh_data, cpu).nxtlist) { - rcu_bh_qs(cpu); - force_quiescent_state(&rcu_bh_state); - } - - /* - * If RCU callbacks are still pending, RCU still needs this CPU. - * So try forcing the callbacks through the grace period. - */ - if (rcu_cpu_has_callbacks(cpu)) { - trace_rcu_prep_idle("More callbacks"); - invoke_rcu_core(); - } else { - trace_rcu_prep_idle("Callbacks drained"); + rcu_try_advance_all_cbs(); + for_each_rcu_flavor(rsp) { + rdp = per_cpu_ptr(rsp->rda, cpu); + if (cpu_has_callbacks_ready_to_invoke(rdp)) + invoke_rcu_core(); } } @@ -2015,16 +1862,13 @@ early_initcall(rcu_register_oom_notifier); static void print_cpu_stall_fast_no_hz(char *cp, int cpu) { struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu); - struct timer_list *tltp = &rdtp->idle_gp_timer; - char c; + unsigned long nlpd = rdtp->nonlazy_posted - rdtp->nonlazy_posted_snap; - c = rdtp->dyntick_holdoff == jiffies ? 'H' : '.'; - if (timer_pending(tltp)) - sprintf(cp, "drain=%d %c timer=%lu", - rdtp->dyntick_drain, c, tltp->expires - jiffies); - else - sprintf(cp, "drain=%d %c timer not pending", - rdtp->dyntick_drain, c); + sprintf(cp, "last_accelerate: %04lx/%04lx, nonlazy_posted: %ld, %c%c", + rdtp->last_accelerate & 0xffff, jiffies & 0xffff, + ulong2long(nlpd), + rdtp->all_lazy ? 'L' : '.', + rdtp->tick_nohz_enabled_snap ? '.' : 'D'); } #else /* #ifdef CONFIG_RCU_FAST_NO_HZ */ @@ -2070,10 +1914,11 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu) ticks_value = rsp->gpnum - rdp->gpnum; } print_cpu_stall_fast_no_hz(fast_no_hz, cpu); - printk(KERN_ERR "\t%d: (%lu %s) idle=%03x/%llx/%d %s\n", + printk(KERN_ERR "\t%d: (%lu %s) idle=%03x/%llx/%d softirq=%u/%u %s\n", cpu, ticks_value, ticks_title, atomic_read(&rdtp->dynticks) & 0xfff, rdtp->dynticks_nesting, rdtp->dynticks_nmi_nesting, + rdp->softirq_snap, kstat_softirqs_cpu(RCU_SOFTIRQ, cpu), fast_no_hz); } @@ -2087,6 +1932,7 @@ static void print_cpu_stall_info_end(void) static void zero_cpu_stall_ticks(struct rcu_data *rdp) { rdp->ticks_this_gp = 0; + rdp->softirq_snap = kstat_softirqs_cpu(RCU_SOFTIRQ, smp_processor_id()); } /* Increment ->ticks_this_gp for all flavors of RCU. */ @@ -2165,8 +2011,49 @@ static int __init parse_rcu_nocb_poll(char *arg) } early_param("rcu_nocb_poll", parse_rcu_nocb_poll); +/* + * Do any no-CBs CPUs need another grace period? + * + * Interrupts must be disabled. If the caller does not hold the root + * rnp_node structure's ->lock, the results are advisory only. + */ +static int rcu_nocb_needs_gp(struct rcu_state *rsp) +{ + struct rcu_node *rnp = rcu_get_root(rsp); + + return rnp->need_future_gp[(ACCESS_ONCE(rnp->completed) + 1) & 0x1]; +} + +/* + * Wake up any no-CBs CPUs' kthreads that were waiting on the just-ended + * grace period. + */ +static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp) +{ + wake_up_all(&rnp->nocb_gp_wq[rnp->completed & 0x1]); +} + +/* + * Set the root rcu_node structure's ->need_future_gp field + * based on the sum of those of all rcu_node structures. This does + * double-count the root rcu_node structure's requests, but this + * is necessary to handle the possibility of a rcu_nocb_kthread() + * having awakened during the time that the rcu_node structures + * were being updated for the end of the previous grace period. + */ +static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq) +{ + rnp->need_future_gp[(rnp->completed + 1) & 0x1] += nrq; +} + +static void rcu_init_one_nocb(struct rcu_node *rnp) +{ + init_waitqueue_head(&rnp->nocb_gp_wq[0]); + init_waitqueue_head(&rnp->nocb_gp_wq[1]); +} + /* Is the specified CPU a no-CPUs CPU? */ -static bool is_nocb_cpu(int cpu) +bool rcu_is_nocb_cpu(int cpu) { if (have_rcu_nocb_mask) return cpumask_test_cpu(cpu, rcu_nocb_mask); @@ -2224,9 +2111,16 @@ static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp, bool lazy) { - if (!is_nocb_cpu(rdp->cpu)) + if (!rcu_is_nocb_cpu(rdp->cpu)) return 0; __call_rcu_nocb_enqueue(rdp, rhp, &rhp->next, 1, lazy); + if (__is_kfree_rcu_offset((unsigned long)rhp->func)) + trace_rcu_kfree_callback(rdp->rsp->name, rhp, + (unsigned long)rhp->func, + rdp->qlen_lazy, rdp->qlen); + else + trace_rcu_callback(rdp->rsp->name, rhp, + rdp->qlen_lazy, rdp->qlen); return 1; } @@ -2241,7 +2135,7 @@ static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp, long qll = rsp->qlen_lazy; /* If this is not a no-CBs CPU, tell the caller to do it the old way. */ - if (!is_nocb_cpu(smp_processor_id())) + if (!rcu_is_nocb_cpu(smp_processor_id())) return 0; rsp->qlen = 0; rsp->qlen_lazy = 0; @@ -2265,95 +2159,36 @@ static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp, } /* - * There must be at least one non-no-CBs CPU in operation at any given - * time, because no-CBs CPUs are not capable of initiating grace periods - * independently. This function therefore complains if the specified - * CPU is the last non-no-CBs CPU, allowing the CPU-hotplug system to - * avoid offlining the last such CPU. (Recursion is a wonderful thing, - * but you have to have a base case!) + * If necessary, kick off a new grace period, and either way wait + * for a subsequent grace period to complete. */ -static bool nocb_cpu_expendable(int cpu) +static void rcu_nocb_wait_gp(struct rcu_data *rdp) { - cpumask_var_t non_nocb_cpus; - int ret; + unsigned long c; + bool d; + unsigned long flags; + struct rcu_node *rnp = rdp->mynode; + + raw_spin_lock_irqsave(&rnp->lock, flags); + c = rcu_start_future_gp(rnp, rdp); + raw_spin_unlock_irqrestore(&rnp->lock, flags); /* - * If there are no no-CB CPUs or if this CPU is not a no-CB CPU, - * then offlining this CPU is harmless. Let it happen. + * Wait for the grace period. Do so interruptibly to avoid messing + * up the load average. */ - if (!have_rcu_nocb_mask || is_nocb_cpu(cpu)) - return 1; - - /* If no memory, play it safe and keep the CPU around. */ - if (!alloc_cpumask_var(&non_nocb_cpus, GFP_NOIO)) - return 0; - cpumask_andnot(non_nocb_cpus, cpu_online_mask, rcu_nocb_mask); - cpumask_clear_cpu(cpu, non_nocb_cpus); - ret = !cpumask_empty(non_nocb_cpus); - free_cpumask_var(non_nocb_cpus); - return ret; -} - -/* - * Helper structure for remote registry of RCU callbacks. - * This is needed for when a no-CBs CPU needs to start a grace period. - * If it just invokes call_rcu(), the resulting callback will be queued, - * which can result in deadlock. - */ -struct rcu_head_remote { - struct rcu_head *rhp; - call_rcu_func_t *crf; - void (*func)(struct rcu_head *rhp); -}; - -/* - * Register a callback as specified by the rcu_head_remote struct. - * This function is intended to be invoked via smp_call_function_single(). - */ -static void call_rcu_local(void *arg) -{ - struct rcu_head_remote *rhrp = - container_of(arg, struct rcu_head_remote, rhp); - - rhrp->crf(rhrp->rhp, rhrp->func); -} - -/* - * Set up an rcu_head_remote structure and the invoke call_rcu_local() - * on CPU 0 (which is guaranteed to be a non-no-CBs CPU) via - * smp_call_function_single(). - */ -static void invoke_crf_remote(struct rcu_head *rhp, - void (*func)(struct rcu_head *rhp), - call_rcu_func_t crf) -{ - struct rcu_head_remote rhr; - - rhr.rhp = rhp; - rhr.crf = crf; - rhr.func = func; - smp_call_function_single(0, call_rcu_local, &rhr, 1); -} - -/* - * Helper functions to be passed to wait_rcu_gp(), each of which - * invokes invoke_crf_remote() to register a callback appropriately. - */ -static void __maybe_unused -call_rcu_preempt_remote(struct rcu_head *rhp, - void (*func)(struct rcu_head *rhp)) -{ - invoke_crf_remote(rhp, func, call_rcu); -} -static void call_rcu_bh_remote(struct rcu_head *rhp, - void (*func)(struct rcu_head *rhp)) -{ - invoke_crf_remote(rhp, func, call_rcu_bh); -} -static void call_rcu_sched_remote(struct rcu_head *rhp, - void (*func)(struct rcu_head *rhp)) -{ - invoke_crf_remote(rhp, func, call_rcu_sched); + trace_rcu_future_gp(rnp, rdp, c, "StartWait"); + for (;;) { + wait_event_interruptible( + rnp->nocb_gp_wq[c & 0x1], + (d = ULONG_CMP_GE(ACCESS_ONCE(rnp->completed), c))); + if (likely(d)) + break; + flush_signals(current); + trace_rcu_future_gp(rnp, rdp, c, "ResumeWait"); + } + trace_rcu_future_gp(rnp, rdp, c, "EndWait"); + smp_mb(); /* Ensure that CB invocation happens after GP end. */ } /* @@ -2390,7 +2225,7 @@ static int rcu_nocb_kthread(void *arg) cl = atomic_long_xchg(&rdp->nocb_q_count_lazy, 0); ACCESS_ONCE(rdp->nocb_p_count) += c; ACCESS_ONCE(rdp->nocb_p_count_lazy) += cl; - wait_rcu_gp(rdp->rsp->call_remote); + rcu_nocb_wait_gp(rdp); /* Each pass through the following loop invokes a callback. */ trace_rcu_batch_start(rdp->rsp->name, cl, c, -1); @@ -2436,36 +2271,40 @@ static void __init rcu_spawn_nocb_kthreads(struct rcu_state *rsp) return; for_each_cpu(cpu, rcu_nocb_mask) { rdp = per_cpu_ptr(rsp->rda, cpu); - t = kthread_run(rcu_nocb_kthread, rdp, "rcuo%d", cpu); + t = kthread_run(rcu_nocb_kthread, rdp, + "rcuo%c/%d", rsp->abbr, cpu); BUG_ON(IS_ERR(t)); ACCESS_ONCE(rdp->nocb_kthread) = t; } } /* Prevent __call_rcu() from enqueuing callbacks on no-CBs CPUs */ -static void init_nocb_callback_list(struct rcu_data *rdp) +static bool init_nocb_callback_list(struct rcu_data *rdp) { if (rcu_nocb_mask == NULL || !cpumask_test_cpu(rdp->cpu, rcu_nocb_mask)) - return; + return false; rdp->nxttail[RCU_NEXT_TAIL] = NULL; + return true; } -/* Initialize the ->call_remote fields in the rcu_state structures. */ -static void __init rcu_init_nocb(void) +#else /* #ifdef CONFIG_RCU_NOCB_CPU */ + +static int rcu_nocb_needs_gp(struct rcu_state *rsp) { -#ifdef CONFIG_PREEMPT_RCU - rcu_preempt_state.call_remote = call_rcu_preempt_remote; -#endif /* #ifdef CONFIG_PREEMPT_RCU */ - rcu_bh_state.call_remote = call_rcu_bh_remote; - rcu_sched_state.call_remote = call_rcu_sched_remote; + return 0; } -#else /* #ifdef CONFIG_RCU_NOCB_CPU */ +static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp) +{ +} -static bool is_nocb_cpu(int cpu) +static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq) +{ +} + +static void rcu_init_one_nocb(struct rcu_node *rnp) { - return false; } static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp, @@ -2480,11 +2319,6 @@ static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp, return 0; } -static bool nocb_cpu_expendable(int cpu) -{ - return 1; -} - static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp) { } @@ -2493,12 +2327,26 @@ static void __init rcu_spawn_nocb_kthreads(struct rcu_state *rsp) { } -static void init_nocb_callback_list(struct rcu_data *rdp) +static bool init_nocb_callback_list(struct rcu_data *rdp) { + return false; } -static void __init rcu_init_nocb(void) +#endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */ + +/* + * An adaptive-ticks CPU can potentially execute in kernel mode for an + * arbitrarily long period of time with the scheduling-clock tick turned + * off. RCU will be paying attention to this CPU because it is in the + * kernel, but the CPU cannot be guaranteed to be executing the RCU state + * machine because the scheduling-clock tick has been disabled. Therefore, + * if an adaptive-ticks CPU is failing to respond to the current grace + * period and has not be idle from an RCU perspective, kick it. + */ +static void rcu_kick_nohz_cpu(int cpu) { +#ifdef CONFIG_NO_HZ_FULL + if (tick_nohz_full_cpu(cpu)) + smp_send_reschedule(cpu); +#endif /* #ifdef CONFIG_NO_HZ_FULL */ } - -#endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */ diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c index 0d095dcaa670..cf6c17412932 100644 --- a/kernel/rcutree_trace.c +++ b/kernel/rcutree_trace.c @@ -46,8 +46,6 @@ #define RCU_TREE_NONCORE #include "rcutree.h" -#define ulong2long(a) (*(long *)(&(a))) - static int r_open(struct inode *inode, struct file *file, const struct seq_operations *op) { @@ -97,7 +95,7 @@ static const struct file_operations rcubarrier_fops = { .open = rcubarrier_open, .read = seq_read, .llseek = no_llseek, - .release = seq_release, + .release = single_release, }; #ifdef CONFIG_RCU_BOOST @@ -208,7 +206,7 @@ static const struct file_operations rcuexp_fops = { .open = rcuexp_open, .read = seq_read, .llseek = no_llseek, - .release = seq_release, + .release = single_release, }; #ifdef CONFIG_RCU_BOOST @@ -308,7 +306,7 @@ static const struct file_operations rcuhier_fops = { .open = rcuhier_open, .read = seq_read, .llseek = no_llseek, - .release = seq_release, + .release = single_release, }; static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp) @@ -350,7 +348,7 @@ static const struct file_operations rcugp_fops = { .open = rcugp_open, .read = seq_read, .llseek = no_llseek, - .release = seq_release, + .release = single_release, }; static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp) diff --git a/kernel/relay.c b/kernel/relay.c index e8cd2027abbd..b91488ba2e5a 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -234,7 +234,6 @@ static void relay_destroy_buf(struct rchan_buf *buf) static void relay_remove_buf(struct kref *kref) { struct rchan_buf *buf = container_of(kref, struct rchan_buf, kref); - buf->chan->cb->remove_buf_file(buf->dentry); relay_destroy_buf(buf); } @@ -484,6 +483,7 @@ static void relay_close_buf(struct rchan_buf *buf) { buf->finalized = 1; del_timer_sync(&buf->timer); + buf->chan->cb->remove_buf_file(buf->dentry); kref_put(&buf->kref, relay_remove_buf); } @@ -588,7 +588,7 @@ struct rchan *relay_open(const char *base_filename, chan->version = RELAYFS_CHANNEL_VERSION; chan->n_subbufs = n_subbufs; chan->subbuf_size = subbuf_size; - chan->alloc_size = FIX_SIZE(subbuf_size * n_subbufs); + chan->alloc_size = PAGE_ALIGN(subbuf_size * n_subbufs); chan->parent = parent; chan->private_data = private_data; if (base_filename) { @@ -1099,8 +1099,7 @@ static size_t relay_file_read_end_pos(struct rchan_buf *buf, static int subbuf_read_actor(size_t read_start, struct rchan_buf *buf, size_t avail, - read_descriptor_t *desc, - read_actor_t actor) + read_descriptor_t *desc) { void *from; int ret = 0; @@ -1121,15 +1120,13 @@ static int subbuf_read_actor(size_t read_start, typedef int (*subbuf_actor_t) (size_t read_start, struct rchan_buf *buf, size_t avail, - read_descriptor_t *desc, - read_actor_t actor); + read_descriptor_t *desc); /* * relay_file_read_subbufs - read count bytes, bridging subbuf boundaries */ static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos, subbuf_actor_t subbuf_actor, - read_actor_t actor, read_descriptor_t *desc) { struct rchan_buf *buf = filp->private_data; @@ -1139,7 +1136,7 @@ static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos, if (!desc->count) return 0; - mutex_lock(&filp->f_path.dentry->d_inode->i_mutex); + mutex_lock(&file_inode(filp)->i_mutex); do { if (!relay_file_read_avail(buf, *ppos)) break; @@ -1150,7 +1147,7 @@ static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos, break; avail = min(desc->count, avail); - ret = subbuf_actor(read_start, buf, avail, desc, actor); + ret = subbuf_actor(read_start, buf, avail, desc); if (desc->error < 0) break; @@ -1159,7 +1156,7 @@ static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos, *ppos = relay_file_read_end_pos(buf, read_start, ret); } } while (desc->count && ret); - mutex_unlock(&filp->f_path.dentry->d_inode->i_mutex); + mutex_unlock(&file_inode(filp)->i_mutex); return desc->written; } @@ -1174,8 +1171,7 @@ static ssize_t relay_file_read(struct file *filp, desc.count = count; desc.arg.buf = buffer; desc.error = 0; - return relay_file_read_subbufs(filp, ppos, subbuf_read_actor, - NULL, &desc); + return relay_file_read_subbufs(filp, ppos, subbuf_read_actor, &desc); } static void relay_consume_bytes(struct rchan_buf *rbuf, int bytes_consumed) diff --git a/kernel/resource.c b/kernel/resource.c index 73f35d4b30b9..d7386986e10e 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -21,6 +21,7 @@ #include <linux/seq_file.h> #include <linux/device.h> #include <linux/pfn.h> +#include <linux/mm.h> #include <asm/io.h> @@ -50,6 +51,14 @@ struct resource_constraint { static DEFINE_RWLOCK(resource_lock); +/* + * For memory hotplug, there is no way to free resource entries allocated + * by boot mem after the system is up. So for reusing the resource entry + * we need to remember the resource. + */ +static struct resource *bootmem_resource_free; +static DEFINE_SPINLOCK(bootmem_resource_lock); + static void *r_next(struct seq_file *m, void *v, loff_t *pos) { struct resource *p = v; @@ -151,6 +160,40 @@ __initcall(ioresources_init); #endif /* CONFIG_PROC_FS */ +static void free_resource(struct resource *res) +{ + if (!res) + return; + + if (!PageSlab(virt_to_head_page(res))) { + spin_lock(&bootmem_resource_lock); + res->sibling = bootmem_resource_free; + bootmem_resource_free = res; + spin_unlock(&bootmem_resource_lock); + } else { + kfree(res); + } +} + +static struct resource *alloc_resource(gfp_t flags) +{ + struct resource *res = NULL; + + spin_lock(&bootmem_resource_lock); + if (bootmem_resource_free) { + res = bootmem_resource_free; + bootmem_resource_free = res->sibling; + } + spin_unlock(&bootmem_resource_lock); + + if (res) + memset(res, 0, sizeof(struct resource)); + else + res = kzalloc(sizeof(struct resource), flags); + + return res; +} + /* Return the conflict entry if you can't request it */ static struct resource * __request_resource(struct resource *root, struct resource *new) { @@ -706,24 +749,13 @@ void insert_resource_expand_to_fit(struct resource *root, struct resource *new) write_unlock(&resource_lock); } -/** - * adjust_resource - modify a resource's start and size - * @res: resource to modify - * @start: new start value - * @size: new size - * - * Given an existing resource, change its start and size to match the - * arguments. Returns 0 on success, -EBUSY if it can't fit. - * Existing children of the resource are assumed to be immutable. - */ -int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size) +static int __adjust_resource(struct resource *res, resource_size_t start, + resource_size_t size) { struct resource *tmp, *parent = res->parent; resource_size_t end = start + size - 1; int result = -EBUSY; - write_lock(&resource_lock); - if (!parent) goto skip; @@ -751,6 +783,26 @@ skip: result = 0; out: + return result; +} + +/** + * adjust_resource - modify a resource's start and size + * @res: resource to modify + * @start: new start value + * @size: new size + * + * Given an existing resource, change its start and size to match the + * arguments. Returns 0 on success, -EBUSY if it can't fit. + * Existing children of the resource are assumed to be immutable. + */ +int adjust_resource(struct resource *res, resource_size_t start, + resource_size_t size) +{ + int result; + + write_lock(&resource_lock); + result = __adjust_resource(res, start, size); write_unlock(&resource_lock); return result; } @@ -762,7 +814,7 @@ static void __init __reserve_region_with_split(struct resource *root, { struct resource *parent = root; struct resource *conflict; - struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC); + struct resource *res = alloc_resource(GFP_ATOMIC); struct resource *next_res = NULL; if (!res) @@ -787,7 +839,7 @@ static void __init __reserve_region_with_split(struct resource *root, /* conflict covered whole area */ if (conflict->start <= res->start && conflict->end >= res->end) { - kfree(res); + free_resource(res); WARN_ON(next_res); break; } @@ -797,10 +849,9 @@ static void __init __reserve_region_with_split(struct resource *root, end = res->end; res->end = conflict->start - 1; if (conflict->end < end) { - next_res = kzalloc(sizeof(*next_res), - GFP_ATOMIC); + next_res = alloc_resource(GFP_ATOMIC); if (!next_res) { - kfree(res); + free_resource(res); break; } next_res->name = name; @@ -890,7 +941,7 @@ struct resource * __request_region(struct resource *parent, const char *name, int flags) { DECLARE_WAITQUEUE(wait, current); - struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); + struct resource *res = alloc_resource(GFP_KERNEL); if (!res) return NULL; @@ -924,7 +975,7 @@ struct resource * __request_region(struct resource *parent, continue; } /* Uhhuh, that didn't work out.. */ - kfree(res); + free_resource(res); res = NULL; break; } @@ -958,7 +1009,7 @@ int __check_region(struct resource *parent, resource_size_t start, return -EBUSY; release_resource(res); - kfree(res); + free_resource(res); return 0; } EXPORT_SYMBOL(__check_region); @@ -998,7 +1049,7 @@ void __release_region(struct resource *parent, resource_size_t start, write_unlock(&resource_lock); if (res->flags & IORESOURCE_MUXED) wake_up(&muxed_resource_wait); - kfree(res); + free_resource(res); return; } p = &res->sibling; @@ -1012,6 +1063,109 @@ void __release_region(struct resource *parent, resource_size_t start, } EXPORT_SYMBOL(__release_region); +#ifdef CONFIG_MEMORY_HOTREMOVE +/** + * release_mem_region_adjustable - release a previously reserved memory region + * @parent: parent resource descriptor + * @start: resource start address + * @size: resource region size + * + * This interface is intended for memory hot-delete. The requested region + * is released from a currently busy memory resource. The requested region + * must either match exactly or fit into a single busy resource entry. In + * the latter case, the remaining resource is adjusted accordingly. + * Existing children of the busy memory resource must be immutable in the + * request. + * + * Note: + * - Additional release conditions, such as overlapping region, can be + * supported after they are confirmed as valid cases. + * - When a busy memory resource gets split into two entries, the code + * assumes that all children remain in the lower address entry for + * simplicity. Enhance this logic when necessary. + */ +int release_mem_region_adjustable(struct resource *parent, + resource_size_t start, resource_size_t size) +{ + struct resource **p; + struct resource *res; + struct resource *new_res; + resource_size_t end; + int ret = -EINVAL; + + end = start + size - 1; + if ((start < parent->start) || (end > parent->end)) + return ret; + + /* The alloc_resource() result gets checked later */ + new_res = alloc_resource(GFP_KERNEL); + + p = &parent->child; + write_lock(&resource_lock); + + while ((res = *p)) { + if (res->start >= end) + break; + + /* look for the next resource if it does not fit into */ + if (res->start > start || res->end < end) { + p = &res->sibling; + continue; + } + + if (!(res->flags & IORESOURCE_MEM)) + break; + + if (!(res->flags & IORESOURCE_BUSY)) { + p = &res->child; + continue; + } + + /* found the target resource; let's adjust accordingly */ + if (res->start == start && res->end == end) { + /* free the whole entry */ + *p = res->sibling; + free_resource(res); + ret = 0; + } else if (res->start == start && res->end != end) { + /* adjust the start */ + ret = __adjust_resource(res, end + 1, + res->end - end); + } else if (res->start != start && res->end == end) { + /* adjust the end */ + ret = __adjust_resource(res, res->start, + start - res->start); + } else { + /* split into two entries */ + if (!new_res) { + ret = -ENOMEM; + break; + } + new_res->name = res->name; + new_res->start = end + 1; + new_res->end = res->end; + new_res->flags = res->flags; + new_res->parent = res->parent; + new_res->sibling = res->sibling; + new_res->child = NULL; + + ret = __adjust_resource(res, res->start, + start - res->start); + if (ret) + break; + res->sibling = new_res; + new_res = NULL; + } + + break; + } + + write_unlock(&resource_lock); + free_resource(new_res); + return ret; +} +#endif /* CONFIG_MEMORY_HOTREMOVE */ + /* * Managed region resource */ diff --git a/kernel/rtmutex-debug.c b/kernel/rtmutex-debug.c index 16502d3a71c8..13b243a323fa 100644 --- a/kernel/rtmutex-debug.c +++ b/kernel/rtmutex-debug.c @@ -17,6 +17,7 @@ * See rt.c in preempt-rt for proper credits and further information */ #include <linux/sched.h> +#include <linux/sched/rt.h> #include <linux/delay.h> #include <linux/export.h> #include <linux/spinlock.h> diff --git a/kernel/rtmutex-tester.c b/kernel/rtmutex-tester.c index 98ec49475460..1d96dd0d93c1 100644 --- a/kernel/rtmutex-tester.c +++ b/kernel/rtmutex-tester.c @@ -10,9 +10,11 @@ #include <linux/kthread.h> #include <linux/export.h> #include <linux/sched.h> +#include <linux/sched/rt.h> #include <linux/spinlock.h> #include <linux/timer.h> #include <linux/freezer.h> +#include <linux/stat.h> #include "rtmutex.h" @@ -365,8 +367,8 @@ static ssize_t sysfs_test_status(struct device *dev, struct device_attribute *at return curr - buf; } -static DEVICE_ATTR(status, 0600, sysfs_test_status, NULL); -static DEVICE_ATTR(command, 0600, NULL, sysfs_test_command); +static DEVICE_ATTR(status, S_IRUSR, sysfs_test_status, NULL); +static DEVICE_ATTR(command, S_IWUSR, NULL, sysfs_test_command); static struct bus_type rttest_subsys = { .name = "rttest", diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c index a242e691c993..1e09308bf2a1 100644 --- a/kernel/rtmutex.c +++ b/kernel/rtmutex.c @@ -13,6 +13,7 @@ #include <linux/spinlock.h> #include <linux/export.h> #include <linux/sched.h> +#include <linux/sched/rt.h> #include <linux/timer.h> #include "rtmutex_common.h" diff --git a/kernel/rwsem.c b/kernel/rwsem.c index b3c6c3fcd847..cfff1435bdfb 100644 --- a/kernel/rwsem.c +++ b/kernel/rwsem.c @@ -126,6 +126,15 @@ void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest) EXPORT_SYMBOL(_down_write_nest_lock); +void down_read_non_owner(struct rw_semaphore *sem) +{ + might_sleep(); + + __down_read(sem); +} + +EXPORT_SYMBOL(down_read_non_owner); + void down_write_nested(struct rw_semaphore *sem, int subclass) { might_sleep(); @@ -136,6 +145,13 @@ void down_write_nested(struct rw_semaphore *sem, int subclass) EXPORT_SYMBOL(down_write_nested); +void up_read_non_owner(struct rw_semaphore *sem) +{ + __up_read(sem); +} + +EXPORT_SYMBOL(up_read_non_owner); + #endif diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile index f06d249e103b..deaf90e4a1de 100644 --- a/kernel/sched/Makefile +++ b/kernel/sched/Makefile @@ -16,3 +16,4 @@ obj-$(CONFIG_SMP) += cpupri.o obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o obj-$(CONFIG_SCHEDSTATS) += stats.o obj-$(CONFIG_SCHED_DEBUG) += debug.o +obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o diff --git a/kernel/sched/auto_group.c b/kernel/sched/auto_group.c index 0984a21076a3..64de5f8b0c9e 100644 --- a/kernel/sched/auto_group.c +++ b/kernel/sched/auto_group.c @@ -35,6 +35,7 @@ static inline void autogroup_destroy(struct kref *kref) ag->tg->rt_se = NULL; ag->tg->rt_rq = NULL; #endif + sched_offline_group(ag->tg); sched_destroy_group(ag->tg); } @@ -76,6 +77,8 @@ static inline struct autogroup *autogroup_create(void) if (IS_ERR(tg)) goto out_free; + sched_online_group(tg, &root_task_group); + kref_init(&ag->kref); init_rwsem(&ag->lock); ag->id = atomic_inc_return(&autogroup_seq_nr); diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c index c685e31492df..c3ae1446461c 100644 --- a/kernel/sched/clock.c +++ b/kernel/sched/clock.c @@ -176,10 +176,36 @@ static u64 sched_clock_remote(struct sched_clock_data *scd) u64 this_clock, remote_clock; u64 *ptr, old_val, val; +#if BITS_PER_LONG != 64 +again: + /* + * Careful here: The local and the remote clock values need to + * be read out atomic as we need to compare the values and + * then update either the local or the remote side. So the + * cmpxchg64 below only protects one readout. + * + * We must reread via sched_clock_local() in the retry case on + * 32bit as an NMI could use sched_clock_local() via the + * tracer and hit between the readout of + * the low32bit and the high 32bit portion. + */ + this_clock = sched_clock_local(my_scd); + /* + * We must enforce atomic readout on 32bit, otherwise the + * update on the remote cpu can hit inbetween the readout of + * the low32bit and the high 32bit portion. + */ + remote_clock = cmpxchg64(&scd->clock, 0, 0); +#else + /* + * On 64bit the read of [my]scd->clock is atomic versus the + * update, so we can avoid the above 32bit dance. + */ sched_clock_local(my_scd); again: this_clock = my_scd->clock; remote_clock = scd->clock; +#endif /* * Use the opportunity that we have both locks diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 26058d0bebba..58453b8272fd 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -83,7 +83,7 @@ #endif #include "sched.h" -#include "../workqueue_sched.h" +#include "../workqueue_internal.h" #include "../smpboot.h" #define CREATE_TRACE_POINTS @@ -512,11 +512,6 @@ static inline void init_hrtick(void) * the target CPU. */ #ifdef CONFIG_SMP - -#ifndef tsk_is_polling -#define tsk_is_polling(t) 0 -#endif - void resched_task(struct task_struct *p) { int cpu; @@ -549,7 +544,7 @@ void resched_cpu(int cpu) raw_spin_unlock_irqrestore(&rq->lock, flags); } -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON /* * In the semi idle case, use the nearest busy cpu for migrating timers * from an idle cpu. This is good for power-savings. @@ -587,7 +582,7 @@ unlock: * account when the CPU goes back to idle and evaluates the timer * wheel for the next timer event. */ -void wake_up_idle_cpu(int cpu) +static void wake_up_idle_cpu(int cpu) { struct rq *rq = cpu_rq(cpu); @@ -617,20 +612,56 @@ void wake_up_idle_cpu(int cpu) smp_send_reschedule(cpu); } +static bool wake_up_full_nohz_cpu(int cpu) +{ + if (tick_nohz_full_cpu(cpu)) { + if (cpu != smp_processor_id() || + tick_nohz_tick_stopped()) + smp_send_reschedule(cpu); + return true; + } + + return false; +} + +void wake_up_nohz_cpu(int cpu) +{ + if (!wake_up_full_nohz_cpu(cpu)) + wake_up_idle_cpu(cpu); +} + static inline bool got_nohz_idle_kick(void) { int cpu = smp_processor_id(); return idle_cpu(cpu) && test_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu)); } -#else /* CONFIG_NO_HZ */ +#else /* CONFIG_NO_HZ_COMMON */ static inline bool got_nohz_idle_kick(void) { return false; } -#endif /* CONFIG_NO_HZ */ +#endif /* CONFIG_NO_HZ_COMMON */ + +#ifdef CONFIG_NO_HZ_FULL +bool sched_can_stop_tick(void) +{ + struct rq *rq; + + rq = this_rq(); + + /* Make sure rq->nr_running update is visible after the IPI */ + smp_rmb(); + + /* More than one running task need preemption */ + if (rq->nr_running > 1) + return false; + + return true; +} +#endif /* CONFIG_NO_HZ_FULL */ void sched_avg_update(struct rq *rq) { @@ -1132,18 +1163,28 @@ EXPORT_SYMBOL_GPL(kick_process); */ static int select_fallback_rq(int cpu, struct task_struct *p) { - const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); + int nid = cpu_to_node(cpu); + const struct cpumask *nodemask = NULL; enum { cpuset, possible, fail } state = cpuset; int dest_cpu; - /* Look for allowed, online CPU in same node. */ - for_each_cpu(dest_cpu, nodemask) { - if (!cpu_online(dest_cpu)) - continue; - if (!cpu_active(dest_cpu)) - continue; - if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) - return dest_cpu; + /* + * If the node that the cpu is on has been offlined, cpu_to_node() + * will return -1. There is no cpu on the node, and we should + * select the cpu on the other node. + */ + if (nid != -1) { + nodemask = cpumask_of_node(nid); + + /* Look for allowed, online CPU in same node. */ + for_each_cpu(dest_cpu, nodemask) { + if (!cpu_online(dest_cpu)) + continue; + if (!cpu_active(dest_cpu)) + continue; + if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) + return dest_cpu; + } } for (;;) { @@ -1278,8 +1319,8 @@ static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) static void ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) { - trace_sched_wakeup(p, true); check_preempt_curr(rq, p, wake_flags); + trace_sched_wakeup(p, true); p->state = TASK_RUNNING; #ifdef CONFIG_SMP @@ -1352,7 +1393,8 @@ static void sched_ttwu_pending(void) void scheduler_ipi(void) { - if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick()) + if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick() + && !tick_nohz_full_cpu(smp_processor_id())) return; /* @@ -1369,6 +1411,7 @@ void scheduler_ipi(void) * somewhat pessimize the simple resched case. */ irq_enter(); + tick_nohz_full_check(); sched_ttwu_pending(); /* @@ -1488,8 +1531,10 @@ static void try_to_wake_up_local(struct task_struct *p) { struct rq *rq = task_rq(p); - BUG_ON(rq != this_rq()); - BUG_ON(p == current); + if (WARN_ON_ONCE(rq != this_rq()) || + WARN_ON_ONCE(p == current)) + return; + lockdep_assert_held(&rq->lock); if (!raw_spin_trylock(&p->pi_lock)) { @@ -1742,9 +1787,8 @@ EXPORT_SYMBOL_GPL(preempt_notifier_unregister); static void fire_sched_in_preempt_notifiers(struct task_struct *curr) { struct preempt_notifier *notifier; - struct hlist_node *node; - hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) + hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) notifier->ops->sched_in(notifier, raw_smp_processor_id()); } @@ -1753,9 +1797,8 @@ fire_sched_out_preempt_notifiers(struct task_struct *curr, struct task_struct *next) { struct preempt_notifier *notifier; - struct hlist_node *node; - hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) + hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) notifier->ops->sched_out(notifier, next); } @@ -1850,6 +1893,8 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev) kprobe_flush_task(prev); put_task_struct(prev); } + + tick_nohz_task_switch(current); } #ifdef CONFIG_SMP @@ -1969,11 +2014,10 @@ context_switch(struct rq *rq, struct task_struct *prev, } /* - * nr_running, nr_uninterruptible and nr_context_switches: + * nr_running and nr_context_switches: * * externally visible scheduler statistics: current number of runnable - * threads, current number of uninterruptible-sleeping threads, total - * number of context switches performed since bootup. + * threads, total number of context switches performed since bootup. */ unsigned long nr_running(void) { @@ -1985,23 +2029,6 @@ unsigned long nr_running(void) return sum; } -unsigned long nr_uninterruptible(void) -{ - unsigned long i, sum = 0; - - for_each_possible_cpu(i) - sum += cpu_rq(i)->nr_uninterruptible; - - /* - * Since we read the counters lockless, it might be slightly - * inaccurate. Do not allow it to go below zero though: - */ - if (unlikely((long)sum < 0)) - sum = 0; - - return sum; -} - unsigned long long nr_context_switches(void) { int i; @@ -2131,7 +2158,7 @@ calc_load(unsigned long load, unsigned long exp, unsigned long active) return load >> FSHIFT; } -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON /* * Handle NO_HZ for the global load-average. * @@ -2357,12 +2384,12 @@ static void calc_global_nohz(void) smp_wmb(); calc_load_idx++; } -#else /* !CONFIG_NO_HZ */ +#else /* !CONFIG_NO_HZ_COMMON */ static inline long calc_load_fold_idle(void) { return 0; } static inline void calc_global_nohz(void) { } -#endif /* CONFIG_NO_HZ */ +#endif /* CONFIG_NO_HZ_COMMON */ /* * calc_load - update the avenrun load estimates 10 ticks after the @@ -2522,7 +2549,7 @@ static void __update_cpu_load(struct rq *this_rq, unsigned long this_load, sched_avg_update(this_rq); } -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON /* * There is no sane way to deal with nohz on smp when using jiffies because the * cpu doing the jiffies update might drift wrt the cpu doing the jiffy reading @@ -2582,7 +2609,7 @@ void update_cpu_load_nohz(void) } raw_spin_unlock(&this_rq->lock); } -#endif /* CONFIG_NO_HZ */ +#endif /* CONFIG_NO_HZ_COMMON */ /* * Called from scheduler_tick() @@ -2709,7 +2736,34 @@ void scheduler_tick(void) rq->idle_balance = idle_cpu(cpu); trigger_load_balance(rq, cpu); #endif + rq_last_tick_reset(rq); +} + +#ifdef CONFIG_NO_HZ_FULL +/** + * scheduler_tick_max_deferment + * + * Keep at least one tick per second when a single + * active task is running because the scheduler doesn't + * yet completely support full dynticks environment. + * + * This makes sure that uptime, CFS vruntime, load + * balancing, etc... continue to move forward, even + * with a very low granularity. + */ +u64 scheduler_tick_max_deferment(void) +{ + struct rq *rq = this_rq(); + unsigned long next, now = ACCESS_ONCE(jiffies); + + next = rq->last_sched_tick + HZ; + + if (time_before_eq(next, now)) + return 0; + + return jiffies_to_usecs(next - now) * NSEC_PER_USEC; } +#endif notrace unsigned long get_parent_ip(unsigned long addr) { @@ -2786,7 +2840,7 @@ static noinline void __schedule_bug(struct task_struct *prev) if (irqs_disabled()) print_irqtrace_events(prev); dump_stack(); - add_taint(TAINT_WARN); + add_taint(TAINT_WARN, LOCKDEP_STILL_OK); } /* @@ -3007,51 +3061,6 @@ void __sched schedule_preempt_disabled(void) preempt_disable(); } -#ifdef CONFIG_MUTEX_SPIN_ON_OWNER - -static inline bool owner_running(struct mutex *lock, struct task_struct *owner) -{ - if (lock->owner != owner) - return false; - - /* - * Ensure we emit the owner->on_cpu, dereference _after_ checking - * lock->owner still matches owner, if that fails, owner might - * point to free()d memory, if it still matches, the rcu_read_lock() - * ensures the memory stays valid. - */ - barrier(); - - return owner->on_cpu; -} - -/* - * Look out! "owner" is an entirely speculative pointer - * access and not reliable. - */ -int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner) -{ - if (!sched_feat(OWNER_SPIN)) - return 0; - - rcu_read_lock(); - while (owner_running(lock, owner)) { - if (need_resched()) - break; - - arch_mutex_cpu_relax(); - } - rcu_read_unlock(); - - /* - * We break out the loop above on need_resched() and when the - * owner changed, which is a sign for heavy contention. Return - * success only when lock->owner is NULL. - */ - return lock->owner == NULL; -} -#endif - #ifdef CONFIG_PREEMPT /* * this is the entry point to schedule() from in-kernel preemption @@ -3092,11 +3101,13 @@ EXPORT_SYMBOL(preempt_schedule); asmlinkage void __sched preempt_schedule_irq(void) { struct thread_info *ti = current_thread_info(); + enum ctx_state prev_state; /* Catch callers which need to be fixed */ BUG_ON(ti->preempt_count || !irqs_disabled()); - user_exit(); + prev_state = exception_enter(); + do { add_preempt_count(PREEMPT_ACTIVE); local_irq_enable(); @@ -3110,6 +3121,8 @@ asmlinkage void __sched preempt_schedule_irq(void) */ barrier(); } while (need_resched()); + + exception_exit(prev_state); } #endif /* CONFIG_PREEMPT */ @@ -3268,7 +3281,8 @@ void complete_all(struct completion *x) EXPORT_SYMBOL(complete_all); static inline long __sched -do_wait_for_common(struct completion *x, long timeout, int state) +do_wait_for_common(struct completion *x, + long (*action)(long), long timeout, int state) { if (!x->done) { DECLARE_WAITQUEUE(wait, current); @@ -3281,7 +3295,7 @@ do_wait_for_common(struct completion *x, long timeout, int state) } __set_current_state(state); spin_unlock_irq(&x->wait.lock); - timeout = schedule_timeout(timeout); + timeout = action(timeout); spin_lock_irq(&x->wait.lock); } while (!x->done && timeout); __remove_wait_queue(&x->wait, &wait); @@ -3292,17 +3306,30 @@ do_wait_for_common(struct completion *x, long timeout, int state) return timeout ?: 1; } -static long __sched -wait_for_common(struct completion *x, long timeout, int state) +static inline long __sched +__wait_for_common(struct completion *x, + long (*action)(long), long timeout, int state) { might_sleep(); spin_lock_irq(&x->wait.lock); - timeout = do_wait_for_common(x, timeout, state); + timeout = do_wait_for_common(x, action, timeout, state); spin_unlock_irq(&x->wait.lock); return timeout; } +static long __sched +wait_for_common(struct completion *x, long timeout, int state) +{ + return __wait_for_common(x, schedule_timeout, timeout, state); +} + +static long __sched +wait_for_common_io(struct completion *x, long timeout, int state) +{ + return __wait_for_common(x, io_schedule_timeout, timeout, state); +} + /** * wait_for_completion: - waits for completion of a task * @x: holds the state of this particular completion @@ -3339,6 +3366,39 @@ wait_for_completion_timeout(struct completion *x, unsigned long timeout) EXPORT_SYMBOL(wait_for_completion_timeout); /** + * wait_for_completion_io: - waits for completion of a task + * @x: holds the state of this particular completion + * + * This waits to be signaled for completion of a specific task. It is NOT + * interruptible and there is no timeout. The caller is accounted as waiting + * for IO. + */ +void __sched wait_for_completion_io(struct completion *x) +{ + wait_for_common_io(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); +} +EXPORT_SYMBOL(wait_for_completion_io); + +/** + * wait_for_completion_io_timeout: - waits for completion of a task (w/timeout) + * @x: holds the state of this particular completion + * @timeout: timeout value in jiffies + * + * This waits for either a completion of a specific task to be signaled or for a + * specified timeout to expire. The timeout is in jiffies. It is not + * interruptible. The caller is accounted as waiting for IO. + * + * The return value is 0 if timed out, and positive (at least 1, or number of + * jiffies left till timeout) if completed. + */ +unsigned long __sched +wait_for_completion_io_timeout(struct completion *x, unsigned long timeout) +{ + return wait_for_common_io(x, timeout, TASK_UNINTERRUPTIBLE); +} +EXPORT_SYMBOL(wait_for_completion_io_timeout); + +/** * wait_for_completion_interruptible: - waits for completion of a task (w/intr) * @x: holds the state of this particular completion * @@ -4089,6 +4149,10 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) get_task_struct(p); rcu_read_unlock(); + if (p->flags & PF_NO_SETAFFINITY) { + retval = -EINVAL; + goto out_put_task; + } if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { retval = -ENOMEM; goto out_put_task; @@ -4364,20 +4428,32 @@ EXPORT_SYMBOL(yield); * It's the caller's job to ensure that the target task struct * can't go away on us before we can do any checks. * - * Returns true if we indeed boosted the target task. + * Returns: + * true (>0) if we indeed boosted the target task. + * false (0) if we failed to boost the target. + * -ESRCH if there's no task to yield to. */ bool __sched yield_to(struct task_struct *p, bool preempt) { struct task_struct *curr = current; struct rq *rq, *p_rq; unsigned long flags; - bool yielded = 0; + int yielded = 0; local_irq_save(flags); rq = this_rq(); again: p_rq = task_rq(p); + /* + * If we're the only runnable task on the rq and target rq also + * has only one task, there's absolutely no point in yielding. + */ + if (rq->nr_running == 1 && p_rq->nr_running == 1) { + yielded = -ESRCH; + goto out_irq; + } + double_rq_lock(rq, p_rq); while (task_rq(p) != p_rq) { double_rq_unlock(rq, p_rq); @@ -4385,13 +4461,13 @@ again: } if (!curr->sched_class->yield_to_task) - goto out; + goto out_unlock; if (curr->sched_class != p->sched_class) - goto out; + goto out_unlock; if (task_running(p_rq, p) || p->state) - goto out; + goto out_unlock; yielded = curr->sched_class->yield_to_task(rq, p, preempt); if (yielded) { @@ -4404,11 +4480,12 @@ again: resched_task(p_rq->curr); } -out: +out_unlock: double_rq_unlock(rq, p_rq); +out_irq: local_irq_restore(flags); - if (yielded) + if (yielded > 0) schedule(); return yielded; @@ -4576,6 +4653,7 @@ void sched_show_task(struct task_struct *p) task_pid_nr(p), ppid, (unsigned long)task_thread_info(p)->flags); + print_worker_info(KERN_INFO, p); show_stack(p, NULL); } @@ -4667,6 +4745,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu) */ idle->sched_class = &idle_sched_class; ftrace_graph_init_idle_task(idle, cpu); + vtime_init_idle(idle); #if defined(CONFIG_SMP) sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu); #endif @@ -4722,11 +4801,6 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) goto out; } - if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) { - ret = -EINVAL; - goto out; - } - do_set_cpus_allowed(p, new_mask); /* Can the task run on the task's current CPU? If so, we're done */ @@ -4948,7 +5022,7 @@ static void sd_free_ctl_entry(struct ctl_table **tablep) } static int min_load_idx = 0; -static int max_load_idx = CPU_LOAD_IDX_MAX; +static int max_load_idx = CPU_LOAD_IDX_MAX-1; static void set_table_entry(struct ctl_table *entry, @@ -6197,7 +6271,7 @@ static void sched_init_numa(void) * 'level' contains the number of unique distances, excluding the * identity distance node_distance(i,i). * - * The sched_domains_nume_distance[] array includes the actual distance + * The sched_domains_numa_distance[] array includes the actual distance * numbers. */ @@ -6810,11 +6884,15 @@ int in_sched_functions(unsigned long addr) } #ifdef CONFIG_CGROUP_SCHED +/* + * Default task group. + * Every task in system belongs to this group at bootup. + */ struct task_group root_task_group; LIST_HEAD(task_groups); #endif -DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask); +DECLARE_PER_CPU(cpumask_var_t, load_balance_mask); void __init sched_init(void) { @@ -6851,7 +6929,7 @@ void __init sched_init(void) #endif /* CONFIG_RT_GROUP_SCHED */ #ifdef CONFIG_CPUMASK_OFFSTACK for_each_possible_cpu(i) { - per_cpu(load_balance_tmpmask, i) = (void *)ptr; + per_cpu(load_balance_mask, i) = (void *)ptr; ptr += cpumask_size(); } #endif /* CONFIG_CPUMASK_OFFSTACK */ @@ -6877,12 +6955,6 @@ void __init sched_init(void) #endif /* CONFIG_CGROUP_SCHED */ -#ifdef CONFIG_CGROUP_CPUACCT - root_cpuacct.cpustat = &kernel_cpustat; - root_cpuacct.cpuusage = alloc_percpu(u64); - /* Too early, not expected to fail */ - BUG_ON(!root_cpuacct.cpuusage); -#endif for_each_possible_cpu(i) { struct rq *rq; @@ -6946,9 +7018,12 @@ void __init sched_init(void) INIT_LIST_HEAD(&rq->cfs_tasks); rq_attach_root(rq, &def_root_domain); -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON rq->nohz_flags = 0; #endif +#ifdef CONFIG_NO_HZ_FULL + rq->last_sched_tick = 0; +#endif #endif init_rq_hrtick(rq); atomic_set(&rq->nr_iowait, 0); @@ -7160,7 +7235,6 @@ static void free_sched_group(struct task_group *tg) struct task_group *sched_create_group(struct task_group *parent) { struct task_group *tg; - unsigned long flags; tg = kzalloc(sizeof(*tg), GFP_KERNEL); if (!tg) @@ -7172,6 +7246,17 @@ struct task_group *sched_create_group(struct task_group *parent) if (!alloc_rt_sched_group(tg, parent)) goto err; + return tg; + +err: + free_sched_group(tg); + return ERR_PTR(-ENOMEM); +} + +void sched_online_group(struct task_group *tg, struct task_group *parent) +{ + unsigned long flags; + spin_lock_irqsave(&task_group_lock, flags); list_add_rcu(&tg->list, &task_groups); @@ -7181,12 +7266,6 @@ struct task_group *sched_create_group(struct task_group *parent) INIT_LIST_HEAD(&tg->children); list_add_rcu(&tg->siblings, &parent->children); spin_unlock_irqrestore(&task_group_lock, flags); - - return tg; - -err: - free_sched_group(tg); - return ERR_PTR(-ENOMEM); } /* rcu callback to free various structures associated with a task group */ @@ -7199,6 +7278,12 @@ static void free_sched_group_rcu(struct rcu_head *rhp) /* Destroy runqueue etc associated with a task group */ void sched_destroy_group(struct task_group *tg) { + /* wait for possible concurrent references to cfs_rqs complete */ + call_rcu(&tg->rcu, free_sched_group_rcu); +} + +void sched_offline_group(struct task_group *tg) +{ unsigned long flags; int i; @@ -7210,9 +7295,6 @@ void sched_destroy_group(struct task_group *tg) list_del_rcu(&tg->list); list_del_rcu(&tg->siblings); spin_unlock_irqrestore(&task_group_lock, flags); - - /* wait for possible concurrent references to cfs_rqs complete */ - call_rcu(&tg->rcu, free_sched_group_rcu); } /* change task's runqueue when it moves between groups. @@ -7397,7 +7479,7 @@ unlock: return err; } -int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) +static int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) { u64 rt_runtime, rt_period; @@ -7409,7 +7491,7 @@ int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); } -long sched_group_rt_runtime(struct task_group *tg) +static long sched_group_rt_runtime(struct task_group *tg) { u64 rt_runtime_us; @@ -7421,7 +7503,7 @@ long sched_group_rt_runtime(struct task_group *tg) return rt_runtime_us; } -int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) +static int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) { u64 rt_runtime, rt_period; @@ -7434,7 +7516,7 @@ int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); } -long sched_group_rt_period(struct task_group *tg) +static long sched_group_rt_period(struct task_group *tg) { u64 rt_period_us; @@ -7469,7 +7551,7 @@ static int sched_rt_global_constraints(void) return ret; } -int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) +static int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) { /* Don't accept realtime tasks when there is no way for them to run */ if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) @@ -7508,6 +7590,25 @@ static int sched_rt_global_constraints(void) } #endif /* CONFIG_RT_GROUP_SCHED */ +int sched_rr_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + int ret; + static DEFINE_MUTEX(mutex); + + mutex_lock(&mutex); + ret = proc_dointvec(table, write, buffer, lenp, ppos); + /* make sure that internally we keep jiffies */ + /* also, writing zero resets timeslice to default */ + if (!ret && write) { + sched_rr_timeslice = sched_rr_timeslice <= 0 ? + RR_TIMESLICE : msecs_to_jiffies(sched_rr_timeslice); + } + mutex_unlock(&mutex); + return ret; +} + int sched_rt_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) @@ -7564,6 +7665,19 @@ static struct cgroup_subsys_state *cpu_cgroup_css_alloc(struct cgroup *cgrp) return &tg->css; } +static int cpu_cgroup_css_online(struct cgroup *cgrp) +{ + struct task_group *tg = cgroup_tg(cgrp); + struct task_group *parent; + + if (!cgrp->parent) + return 0; + + parent = cgroup_tg(cgrp->parent); + sched_online_group(tg, parent); + return 0; +} + static void cpu_cgroup_css_free(struct cgroup *cgrp) { struct task_group *tg = cgroup_tg(cgrp); @@ -7571,6 +7685,13 @@ static void cpu_cgroup_css_free(struct cgroup *cgrp) sched_destroy_group(tg); } +static void cpu_cgroup_css_offline(struct cgroup *cgrp) +{ + struct task_group *tg = cgroup_tg(cgrp); + + sched_offline_group(tg); +} + static int cpu_cgroup_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) { @@ -7926,6 +8047,8 @@ struct cgroup_subsys cpu_cgroup_subsys = { .name = "cpu", .css_alloc = cpu_cgroup_css_alloc, .css_free = cpu_cgroup_css_free, + .css_online = cpu_cgroup_css_online, + .css_offline = cpu_cgroup_css_offline, .can_attach = cpu_cgroup_can_attach, .attach = cpu_cgroup_attach, .exit = cpu_cgroup_exit, @@ -7936,226 +8059,6 @@ struct cgroup_subsys cpu_cgroup_subsys = { #endif /* CONFIG_CGROUP_SCHED */ -#ifdef CONFIG_CGROUP_CPUACCT - -/* - * CPU accounting code for task groups. - * - * Based on the work by Paul Menage (menage@google.com) and Balbir Singh - * (balbir@in.ibm.com). - */ - -struct cpuacct root_cpuacct; - -/* create a new cpu accounting group */ -static struct cgroup_subsys_state *cpuacct_css_alloc(struct cgroup *cgrp) -{ - struct cpuacct *ca; - - if (!cgrp->parent) - return &root_cpuacct.css; - - ca = kzalloc(sizeof(*ca), GFP_KERNEL); - if (!ca) - goto out; - - ca->cpuusage = alloc_percpu(u64); - if (!ca->cpuusage) - goto out_free_ca; - - ca->cpustat = alloc_percpu(struct kernel_cpustat); - if (!ca->cpustat) - goto out_free_cpuusage; - - return &ca->css; - -out_free_cpuusage: - free_percpu(ca->cpuusage); -out_free_ca: - kfree(ca); -out: - return ERR_PTR(-ENOMEM); -} - -/* destroy an existing cpu accounting group */ -static void cpuacct_css_free(struct cgroup *cgrp) -{ - struct cpuacct *ca = cgroup_ca(cgrp); - - free_percpu(ca->cpustat); - free_percpu(ca->cpuusage); - kfree(ca); -} - -static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) -{ - u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); - u64 data; - -#ifndef CONFIG_64BIT - /* - * Take rq->lock to make 64-bit read safe on 32-bit platforms. - */ - raw_spin_lock_irq(&cpu_rq(cpu)->lock); - data = *cpuusage; - raw_spin_unlock_irq(&cpu_rq(cpu)->lock); -#else - data = *cpuusage; -#endif - - return data; -} - -static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) -{ - u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); - -#ifndef CONFIG_64BIT - /* - * Take rq->lock to make 64-bit write safe on 32-bit platforms. - */ - raw_spin_lock_irq(&cpu_rq(cpu)->lock); - *cpuusage = val; - raw_spin_unlock_irq(&cpu_rq(cpu)->lock); -#else - *cpuusage = val; -#endif -} - -/* return total cpu usage (in nanoseconds) of a group */ -static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) -{ - struct cpuacct *ca = cgroup_ca(cgrp); - u64 totalcpuusage = 0; - int i; - - for_each_present_cpu(i) - totalcpuusage += cpuacct_cpuusage_read(ca, i); - - return totalcpuusage; -} - -static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, - u64 reset) -{ - struct cpuacct *ca = cgroup_ca(cgrp); - int err = 0; - int i; - - if (reset) { - err = -EINVAL; - goto out; - } - - for_each_present_cpu(i) - cpuacct_cpuusage_write(ca, i, 0); - -out: - return err; -} - -static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, - struct seq_file *m) -{ - struct cpuacct *ca = cgroup_ca(cgroup); - u64 percpu; - int i; - - for_each_present_cpu(i) { - percpu = cpuacct_cpuusage_read(ca, i); - seq_printf(m, "%llu ", (unsigned long long) percpu); - } - seq_printf(m, "\n"); - return 0; -} - -static const char *cpuacct_stat_desc[] = { - [CPUACCT_STAT_USER] = "user", - [CPUACCT_STAT_SYSTEM] = "system", -}; - -static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, - struct cgroup_map_cb *cb) -{ - struct cpuacct *ca = cgroup_ca(cgrp); - int cpu; - s64 val = 0; - - for_each_online_cpu(cpu) { - struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu); - val += kcpustat->cpustat[CPUTIME_USER]; - val += kcpustat->cpustat[CPUTIME_NICE]; - } - val = cputime64_to_clock_t(val); - cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_USER], val); - - val = 0; - for_each_online_cpu(cpu) { - struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu); - val += kcpustat->cpustat[CPUTIME_SYSTEM]; - val += kcpustat->cpustat[CPUTIME_IRQ]; - val += kcpustat->cpustat[CPUTIME_SOFTIRQ]; - } - - val = cputime64_to_clock_t(val); - cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val); - - return 0; -} - -static struct cftype files[] = { - { - .name = "usage", - .read_u64 = cpuusage_read, - .write_u64 = cpuusage_write, - }, - { - .name = "usage_percpu", - .read_seq_string = cpuacct_percpu_seq_read, - }, - { - .name = "stat", - .read_map = cpuacct_stats_show, - }, - { } /* terminate */ -}; - -/* - * charge this task's execution time to its accounting group. - * - * called with rq->lock held. - */ -void cpuacct_charge(struct task_struct *tsk, u64 cputime) -{ - struct cpuacct *ca; - int cpu; - - if (unlikely(!cpuacct_subsys.active)) - return; - - cpu = task_cpu(tsk); - - rcu_read_lock(); - - ca = task_ca(tsk); - - for (; ca; ca = parent_ca(ca)) { - u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); - *cpuusage += cputime; - } - - rcu_read_unlock(); -} - -struct cgroup_subsys cpuacct_subsys = { - .name = "cpuacct", - .css_alloc = cpuacct_css_alloc, - .css_free = cpuacct_css_free, - .subsys_id = cpuacct_subsys_id, - .base_cftypes = files, -}; -#endif /* CONFIG_CGROUP_CPUACCT */ - void dump_cpu_task(int cpu) { pr_info("Task dump for CPU %d:\n", cpu); diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c new file mode 100644 index 000000000000..dbb7e2cd95eb --- /dev/null +++ b/kernel/sched/cpuacct.c @@ -0,0 +1,296 @@ +#include <linux/cgroup.h> +#include <linux/slab.h> +#include <linux/percpu.h> +#include <linux/spinlock.h> +#include <linux/cpumask.h> +#include <linux/seq_file.h> +#include <linux/rcupdate.h> +#include <linux/kernel_stat.h> +#include <linux/err.h> + +#include "sched.h" + +/* + * CPU accounting code for task groups. + * + * Based on the work by Paul Menage (menage@google.com) and Balbir Singh + * (balbir@in.ibm.com). + */ + +/* Time spent by the tasks of the cpu accounting group executing in ... */ +enum cpuacct_stat_index { + CPUACCT_STAT_USER, /* ... user mode */ + CPUACCT_STAT_SYSTEM, /* ... kernel mode */ + + CPUACCT_STAT_NSTATS, +}; + +/* track cpu usage of a group of tasks and its child groups */ +struct cpuacct { + struct cgroup_subsys_state css; + /* cpuusage holds pointer to a u64-type object on every cpu */ + u64 __percpu *cpuusage; + struct kernel_cpustat __percpu *cpustat; +}; + +/* return cpu accounting group corresponding to this container */ +static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) +{ + return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), + struct cpuacct, css); +} + +/* return cpu accounting group to which this task belongs */ +static inline struct cpuacct *task_ca(struct task_struct *tsk) +{ + return container_of(task_subsys_state(tsk, cpuacct_subsys_id), + struct cpuacct, css); +} + +static inline struct cpuacct *__parent_ca(struct cpuacct *ca) +{ + return cgroup_ca(ca->css.cgroup->parent); +} + +static inline struct cpuacct *parent_ca(struct cpuacct *ca) +{ + if (!ca->css.cgroup->parent) + return NULL; + return cgroup_ca(ca->css.cgroup->parent); +} + +static DEFINE_PER_CPU(u64, root_cpuacct_cpuusage); +static struct cpuacct root_cpuacct = { + .cpustat = &kernel_cpustat, + .cpuusage = &root_cpuacct_cpuusage, +}; + +/* create a new cpu accounting group */ +static struct cgroup_subsys_state *cpuacct_css_alloc(struct cgroup *cgrp) +{ + struct cpuacct *ca; + + if (!cgrp->parent) + return &root_cpuacct.css; + + ca = kzalloc(sizeof(*ca), GFP_KERNEL); + if (!ca) + goto out; + + ca->cpuusage = alloc_percpu(u64); + if (!ca->cpuusage) + goto out_free_ca; + + ca->cpustat = alloc_percpu(struct kernel_cpustat); + if (!ca->cpustat) + goto out_free_cpuusage; + + return &ca->css; + +out_free_cpuusage: + free_percpu(ca->cpuusage); +out_free_ca: + kfree(ca); +out: + return ERR_PTR(-ENOMEM); +} + +/* destroy an existing cpu accounting group */ +static void cpuacct_css_free(struct cgroup *cgrp) +{ + struct cpuacct *ca = cgroup_ca(cgrp); + + free_percpu(ca->cpustat); + free_percpu(ca->cpuusage); + kfree(ca); +} + +static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) +{ + u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); + u64 data; + +#ifndef CONFIG_64BIT + /* + * Take rq->lock to make 64-bit read safe on 32-bit platforms. + */ + raw_spin_lock_irq(&cpu_rq(cpu)->lock); + data = *cpuusage; + raw_spin_unlock_irq(&cpu_rq(cpu)->lock); +#else + data = *cpuusage; +#endif + + return data; +} + +static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) +{ + u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); + +#ifndef CONFIG_64BIT + /* + * Take rq->lock to make 64-bit write safe on 32-bit platforms. + */ + raw_spin_lock_irq(&cpu_rq(cpu)->lock); + *cpuusage = val; + raw_spin_unlock_irq(&cpu_rq(cpu)->lock); +#else + *cpuusage = val; +#endif +} + +/* return total cpu usage (in nanoseconds) of a group */ +static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) +{ + struct cpuacct *ca = cgroup_ca(cgrp); + u64 totalcpuusage = 0; + int i; + + for_each_present_cpu(i) + totalcpuusage += cpuacct_cpuusage_read(ca, i); + + return totalcpuusage; +} + +static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, + u64 reset) +{ + struct cpuacct *ca = cgroup_ca(cgrp); + int err = 0; + int i; + + if (reset) { + err = -EINVAL; + goto out; + } + + for_each_present_cpu(i) + cpuacct_cpuusage_write(ca, i, 0); + +out: + return err; +} + +static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, + struct seq_file *m) +{ + struct cpuacct *ca = cgroup_ca(cgroup); + u64 percpu; + int i; + + for_each_present_cpu(i) { + percpu = cpuacct_cpuusage_read(ca, i); + seq_printf(m, "%llu ", (unsigned long long) percpu); + } + seq_printf(m, "\n"); + return 0; +} + +static const char * const cpuacct_stat_desc[] = { + [CPUACCT_STAT_USER] = "user", + [CPUACCT_STAT_SYSTEM] = "system", +}; + +static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, + struct cgroup_map_cb *cb) +{ + struct cpuacct *ca = cgroup_ca(cgrp); + int cpu; + s64 val = 0; + + for_each_online_cpu(cpu) { + struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu); + val += kcpustat->cpustat[CPUTIME_USER]; + val += kcpustat->cpustat[CPUTIME_NICE]; + } + val = cputime64_to_clock_t(val); + cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_USER], val); + + val = 0; + for_each_online_cpu(cpu) { + struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu); + val += kcpustat->cpustat[CPUTIME_SYSTEM]; + val += kcpustat->cpustat[CPUTIME_IRQ]; + val += kcpustat->cpustat[CPUTIME_SOFTIRQ]; + } + + val = cputime64_to_clock_t(val); + cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val); + + return 0; +} + +static struct cftype files[] = { + { + .name = "usage", + .read_u64 = cpuusage_read, + .write_u64 = cpuusage_write, + }, + { + .name = "usage_percpu", + .read_seq_string = cpuacct_percpu_seq_read, + }, + { + .name = "stat", + .read_map = cpuacct_stats_show, + }, + { } /* terminate */ +}; + +/* + * charge this task's execution time to its accounting group. + * + * called with rq->lock held. + */ +void cpuacct_charge(struct task_struct *tsk, u64 cputime) +{ + struct cpuacct *ca; + int cpu; + + cpu = task_cpu(tsk); + + rcu_read_lock(); + + ca = task_ca(tsk); + + while (true) { + u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); + *cpuusage += cputime; + + ca = parent_ca(ca); + if (!ca) + break; + } + + rcu_read_unlock(); +} + +/* + * Add user/system time to cpuacct. + * + * Note: it's the caller that updates the account of the root cgroup. + */ +void cpuacct_account_field(struct task_struct *p, int index, u64 val) +{ + struct kernel_cpustat *kcpustat; + struct cpuacct *ca; + + rcu_read_lock(); + ca = task_ca(p); + while (ca != &root_cpuacct) { + kcpustat = this_cpu_ptr(ca->cpustat); + kcpustat->cpustat[index] += val; + ca = __parent_ca(ca); + } + rcu_read_unlock(); +} + +struct cgroup_subsys cpuacct_subsys = { + .name = "cpuacct", + .css_alloc = cpuacct_css_alloc, + .css_free = cpuacct_css_free, + .subsys_id = cpuacct_subsys_id, + .base_cftypes = files, + .early_init = 1, +}; diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h new file mode 100644 index 000000000000..ed605624a5e7 --- /dev/null +++ b/kernel/sched/cpuacct.h @@ -0,0 +1,17 @@ +#ifdef CONFIG_CGROUP_CPUACCT + +extern void cpuacct_charge(struct task_struct *tsk, u64 cputime); +extern void cpuacct_account_field(struct task_struct *p, int index, u64 val); + +#else + +static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) +{ +} + +static inline void +cpuacct_account_field(struct task_struct *p, int index, u64 val) +{ +} + +#endif diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c index 23aa789c53ee..1095e878a46f 100644 --- a/kernel/sched/cpupri.c +++ b/kernel/sched/cpupri.c @@ -28,6 +28,8 @@ */ #include <linux/gfp.h> +#include <linux/sched.h> +#include <linux/sched/rt.h> #include "cpupri.h" /* Convert between a 140 based task->prio, and our 102 based cpupri */ diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 293b202fcf79..cc2dc3eea8a3 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -3,6 +3,7 @@ #include <linux/tsacct_kern.h> #include <linux/kernel_stat.h> #include <linux/static_key.h> +#include <linux/context_tracking.h> #include "sched.h" @@ -114,10 +115,6 @@ static int irqtime_account_si_update(void) static inline void task_group_account_field(struct task_struct *p, int index, u64 tmp) { -#ifdef CONFIG_CGROUP_CPUACCT - struct kernel_cpustat *kcpustat; - struct cpuacct *ca; -#endif /* * Since all updates are sure to touch the root cgroup, we * get ourselves ahead and touch it first. If the root cgroup @@ -126,19 +123,7 @@ static inline void task_group_account_field(struct task_struct *p, int index, */ __get_cpu_var(kernel_cpustat).cpustat[index] += tmp; -#ifdef CONFIG_CGROUP_CPUACCT - if (unlikely(!cpuacct_subsys.active)) - return; - - rcu_read_lock(); - ca = task_ca(p); - while (ca && (ca != &root_cpuacct)) { - kcpustat = this_cpu_ptr(ca->cpustat); - kcpustat->cpustat[index] += tmp; - ca = parent_ca(ca); - } - rcu_read_unlock(); -#endif + cpuacct_account_field(p, index, tmp); } /* @@ -163,7 +148,7 @@ void account_user_time(struct task_struct *p, cputime_t cputime, task_group_account_field(p, index, (__force u64) cputime); /* Account for user time used */ - acct_update_integrals(p); + acct_account_cputime(p); } /* @@ -213,7 +198,7 @@ void __account_system_time(struct task_struct *p, cputime_t cputime, task_group_account_field(p, index, (__force u64) cputime); /* Account for system time used */ - acct_update_integrals(p); + acct_account_cputime(p); } /* @@ -295,6 +280,7 @@ static __always_inline bool steal_account_process_tick(void) void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times) { struct signal_struct *sig = tsk->signal; + cputime_t utime, stime; struct task_struct *t; times->utime = sig->utime; @@ -308,16 +294,15 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times) t = tsk; do { - times->utime += t->utime; - times->stime += t->stime; + task_cputime(t, &utime, &stime); + times->utime += utime; + times->stime += stime; times->sum_exec_runtime += task_sched_runtime(t); } while_each_thread(tsk, t); out: rcu_read_unlock(); } -#ifndef CONFIG_VIRT_CPU_ACCOUNTING - #ifdef CONFIG_IRQ_TIME_ACCOUNTING /* * Account a tick to a process and cpustat @@ -382,12 +367,90 @@ static void irqtime_account_idle_ticks(int ticks) irqtime_account_process_tick(current, 0, rq); } #else /* CONFIG_IRQ_TIME_ACCOUNTING */ -static void irqtime_account_idle_ticks(int ticks) {} -static void irqtime_account_process_tick(struct task_struct *p, int user_tick, +static inline void irqtime_account_idle_ticks(int ticks) {} +static inline void irqtime_account_process_tick(struct task_struct *p, int user_tick, struct rq *rq) {} #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ /* + * Use precise platform statistics if available: + */ +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + +#ifndef __ARCH_HAS_VTIME_TASK_SWITCH +void vtime_task_switch(struct task_struct *prev) +{ + if (!vtime_accounting_enabled()) + return; + + if (is_idle_task(prev)) + vtime_account_idle(prev); + else + vtime_account_system(prev); + +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE + vtime_account_user(prev); +#endif + arch_vtime_task_switch(prev); +} +#endif + +/* + * Archs that account the whole time spent in the idle task + * (outside irq) as idle time can rely on this and just implement + * vtime_account_system() and vtime_account_idle(). Archs that + * have other meaning of the idle time (s390 only includes the + * time spent by the CPU when it's in low power mode) must override + * vtime_account(). + */ +#ifndef __ARCH_HAS_VTIME_ACCOUNT +void vtime_account_irq_enter(struct task_struct *tsk) +{ + if (!vtime_accounting_enabled()) + return; + + if (!in_interrupt()) { + /* + * If we interrupted user, context_tracking_in_user() + * is 1 because the context tracking don't hook + * on irq entry/exit. This way we know if + * we need to flush user time on kernel entry. + */ + if (context_tracking_in_user()) { + vtime_account_user(tsk); + return; + } + + if (is_idle_task(tsk)) { + vtime_account_idle(tsk); + return; + } + } + vtime_account_system(tsk); +} +EXPORT_SYMBOL_GPL(vtime_account_irq_enter); +#endif /* __ARCH_HAS_VTIME_ACCOUNT */ +#endif /* CONFIG_VIRT_CPU_ACCOUNTING */ + + +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE +void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st) +{ + *ut = p->utime; + *st = p->stime; +} + +void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st) +{ + struct task_cputime cputime; + + thread_group_cputime(p, &cputime); + + *ut = cputime.utime; + *st = cputime.stime; +} +#else /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */ +/* * Account a single tick of cpu time. * @p: the process that the cpu time gets accounted to * @user_tick: indicates if the tick is a user or a system tick @@ -397,6 +460,9 @@ void account_process_tick(struct task_struct *p, int user_tick) cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); struct rq *rq = this_rq(); + if (vtime_accounting_enabled()) + return; + if (sched_clock_irqtime) { irqtime_account_process_tick(p, user_tick, rq); return; @@ -439,88 +505,49 @@ void account_idle_ticks(unsigned long ticks) account_idle_time(jiffies_to_cputime(ticks)); } -#endif - /* - * Use precise platform statistics if available: + * Perform (stime * rtime) / total, but avoid multiplication overflow by + * loosing precision when the numbers are big. */ -#ifdef CONFIG_VIRT_CPU_ACCOUNTING -void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st) -{ - *ut = p->utime; - *st = p->stime; -} - -void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st) -{ - struct task_cputime cputime; - - thread_group_cputime(p, &cputime); - - *ut = cputime.utime; - *st = cputime.stime; -} - -void vtime_account_system_irqsafe(struct task_struct *tsk) +static cputime_t scale_stime(u64 stime, u64 rtime, u64 total) { - unsigned long flags; - - local_irq_save(flags); - vtime_account_system(tsk); - local_irq_restore(flags); -} -EXPORT_SYMBOL_GPL(vtime_account_system_irqsafe); - -#ifndef __ARCH_HAS_VTIME_TASK_SWITCH -void vtime_task_switch(struct task_struct *prev) -{ - if (is_idle_task(prev)) - vtime_account_idle(prev); - else - vtime_account_system(prev); - - vtime_account_user(prev); - arch_vtime_task_switch(prev); -} -#endif - -/* - * Archs that account the whole time spent in the idle task - * (outside irq) as idle time can rely on this and just implement - * vtime_account_system() and vtime_account_idle(). Archs that - * have other meaning of the idle time (s390 only includes the - * time spent by the CPU when it's in low power mode) must override - * vtime_account(). - */ -#ifndef __ARCH_HAS_VTIME_ACCOUNT -void vtime_account(struct task_struct *tsk) -{ - if (in_interrupt() || !is_idle_task(tsk)) - vtime_account_system(tsk); - else - vtime_account_idle(tsk); -} -EXPORT_SYMBOL_GPL(vtime_account); -#endif /* __ARCH_HAS_VTIME_ACCOUNT */ - -#else - -#ifndef nsecs_to_cputime -# define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs) -#endif - -static cputime_t scale_utime(cputime_t utime, cputime_t rtime, cputime_t total) -{ - u64 temp = (__force u64) rtime; - - temp *= (__force u64) utime; - - if (sizeof(cputime_t) == 4) - temp = div_u64(temp, (__force u32) total); - else - temp = div64_u64(temp, (__force u64) total); + u64 scaled; + + for (;;) { + /* Make sure "rtime" is the bigger of stime/rtime */ + if (stime > rtime) { + u64 tmp = rtime; rtime = stime; stime = tmp; + } + + /* Make sure 'total' fits in 32 bits */ + if (total >> 32) + goto drop_precision; + + /* Does rtime (and thus stime) fit in 32 bits? */ + if (!(rtime >> 32)) + break; + + /* Can we just balance rtime/stime rather than dropping bits? */ + if (stime >> 31) + goto drop_precision; + + /* We can grow stime and shrink rtime and try to make them both fit */ + stime <<= 1; + rtime >>= 1; + continue; + +drop_precision: + /* We drop from rtime, it has more bits than stime */ + rtime >>= 1; + total >>= 1; + } - return (__force cputime_t) temp; + /* + * Make sure gcc understands that this is a 32x32->64 multiply, + * followed by a 64/32->64 divide. + */ + scaled = div_u64((u64) (u32) stime * (u64) (u32) rtime, (u32)total); + return (__force cputime_t) scaled; } /* @@ -531,10 +558,16 @@ static void cputime_adjust(struct task_cputime *curr, struct cputime *prev, cputime_t *ut, cputime_t *st) { - cputime_t rtime, utime, total; + cputime_t rtime, stime, utime, total; + + if (vtime_accounting_enabled()) { + *ut = curr->utime; + *st = curr->stime; + return; + } - utime = curr->utime; - total = utime + curr->stime; + stime = curr->stime; + total = stime + curr->utime; /* * Tick based cputime accounting depend on random scheduling @@ -548,19 +581,32 @@ static void cputime_adjust(struct task_cputime *curr, */ rtime = nsecs_to_cputime(curr->sum_exec_runtime); - if (total) - utime = scale_utime(utime, rtime, total); - else - utime = rtime; + /* + * Update userspace visible utime/stime values only if actual execution + * time is bigger than already exported. Note that can happen, that we + * provided bigger values due to scaling inaccuracy on big numbers. + */ + if (prev->stime + prev->utime >= rtime) + goto out; + + if (total) { + stime = scale_stime((__force u64)stime, + (__force u64)rtime, (__force u64)total); + utime = rtime - stime; + } else { + stime = rtime; + utime = 0; + } /* * If the tick based count grows faster than the scheduler one, * the result of the scaling may go backward. * Let's enforce monotonicity. */ + prev->stime = max(prev->stime, stime); prev->utime = max(prev->utime, utime); - prev->stime = max(prev->stime, rtime - prev->utime); +out: *ut = prev->utime; *st = prev->stime; } @@ -568,11 +614,10 @@ static void cputime_adjust(struct task_cputime *curr, void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st) { struct task_cputime cputime = { - .utime = p->utime, - .stime = p->stime, .sum_exec_runtime = p->se.sum_exec_runtime, }; + task_cputime(p, &cputime.utime, &cputime.stime); cputime_adjust(&cputime, &p->prev_cputime, ut, st); } @@ -586,4 +631,221 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime thread_group_cputime(p, &cputime); cputime_adjust(&cputime, &p->signal->prev_cputime, ut, st); } -#endif +#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */ + +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN +static unsigned long long vtime_delta(struct task_struct *tsk) +{ + unsigned long long clock; + + clock = local_clock(); + if (clock < tsk->vtime_snap) + return 0; + + return clock - tsk->vtime_snap; +} + +static cputime_t get_vtime_delta(struct task_struct *tsk) +{ + unsigned long long delta = vtime_delta(tsk); + + WARN_ON_ONCE(tsk->vtime_snap_whence == VTIME_SLEEPING); + tsk->vtime_snap += delta; + + /* CHECKME: always safe to convert nsecs to cputime? */ + return nsecs_to_cputime(delta); +} + +static void __vtime_account_system(struct task_struct *tsk) +{ + cputime_t delta_cpu = get_vtime_delta(tsk); + + account_system_time(tsk, irq_count(), delta_cpu, cputime_to_scaled(delta_cpu)); +} + +void vtime_account_system(struct task_struct *tsk) +{ + if (!vtime_accounting_enabled()) + return; + + write_seqlock(&tsk->vtime_seqlock); + __vtime_account_system(tsk); + write_sequnlock(&tsk->vtime_seqlock); +} + +void vtime_account_irq_exit(struct task_struct *tsk) +{ + if (!vtime_accounting_enabled()) + return; + + write_seqlock(&tsk->vtime_seqlock); + if (context_tracking_in_user()) + tsk->vtime_snap_whence = VTIME_USER; + __vtime_account_system(tsk); + write_sequnlock(&tsk->vtime_seqlock); +} + +void vtime_account_user(struct task_struct *tsk) +{ + cputime_t delta_cpu; + + if (!vtime_accounting_enabled()) + return; + + delta_cpu = get_vtime_delta(tsk); + + write_seqlock(&tsk->vtime_seqlock); + tsk->vtime_snap_whence = VTIME_SYS; + account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu)); + write_sequnlock(&tsk->vtime_seqlock); +} + +void vtime_user_enter(struct task_struct *tsk) +{ + if (!vtime_accounting_enabled()) + return; + + write_seqlock(&tsk->vtime_seqlock); + tsk->vtime_snap_whence = VTIME_USER; + __vtime_account_system(tsk); + write_sequnlock(&tsk->vtime_seqlock); +} + +void vtime_guest_enter(struct task_struct *tsk) +{ + write_seqlock(&tsk->vtime_seqlock); + __vtime_account_system(tsk); + current->flags |= PF_VCPU; + write_sequnlock(&tsk->vtime_seqlock); +} + +void vtime_guest_exit(struct task_struct *tsk) +{ + write_seqlock(&tsk->vtime_seqlock); + __vtime_account_system(tsk); + current->flags &= ~PF_VCPU; + write_sequnlock(&tsk->vtime_seqlock); +} + +void vtime_account_idle(struct task_struct *tsk) +{ + cputime_t delta_cpu = get_vtime_delta(tsk); + + account_idle_time(delta_cpu); +} + +bool vtime_accounting_enabled(void) +{ + return context_tracking_active(); +} + +void arch_vtime_task_switch(struct task_struct *prev) +{ + write_seqlock(&prev->vtime_seqlock); + prev->vtime_snap_whence = VTIME_SLEEPING; + write_sequnlock(&prev->vtime_seqlock); + + write_seqlock(¤t->vtime_seqlock); + current->vtime_snap_whence = VTIME_SYS; + current->vtime_snap = sched_clock(); + write_sequnlock(¤t->vtime_seqlock); +} + +void vtime_init_idle(struct task_struct *t) +{ + unsigned long flags; + + write_seqlock_irqsave(&t->vtime_seqlock, flags); + t->vtime_snap_whence = VTIME_SYS; + t->vtime_snap = sched_clock(); + write_sequnlock_irqrestore(&t->vtime_seqlock, flags); +} + +cputime_t task_gtime(struct task_struct *t) +{ + unsigned int seq; + cputime_t gtime; + + do { + seq = read_seqbegin(&t->vtime_seqlock); + + gtime = t->gtime; + if (t->flags & PF_VCPU) + gtime += vtime_delta(t); + + } while (read_seqretry(&t->vtime_seqlock, seq)); + + return gtime; +} + +/* + * Fetch cputime raw values from fields of task_struct and + * add up the pending nohz execution time since the last + * cputime snapshot. + */ +static void +fetch_task_cputime(struct task_struct *t, + cputime_t *u_dst, cputime_t *s_dst, + cputime_t *u_src, cputime_t *s_src, + cputime_t *udelta, cputime_t *sdelta) +{ + unsigned int seq; + unsigned long long delta; + + do { + *udelta = 0; + *sdelta = 0; + + seq = read_seqbegin(&t->vtime_seqlock); + + if (u_dst) + *u_dst = *u_src; + if (s_dst) + *s_dst = *s_src; + + /* Task is sleeping, nothing to add */ + if (t->vtime_snap_whence == VTIME_SLEEPING || + is_idle_task(t)) + continue; + + delta = vtime_delta(t); + + /* + * Task runs either in user or kernel space, add pending nohz time to + * the right place. + */ + if (t->vtime_snap_whence == VTIME_USER || t->flags & PF_VCPU) { + *udelta = delta; + } else { + if (t->vtime_snap_whence == VTIME_SYS) + *sdelta = delta; + } + } while (read_seqretry(&t->vtime_seqlock, seq)); +} + + +void task_cputime(struct task_struct *t, cputime_t *utime, cputime_t *stime) +{ + cputime_t udelta, sdelta; + + fetch_task_cputime(t, utime, stime, &t->utime, + &t->stime, &udelta, &sdelta); + if (utime) + *utime += udelta; + if (stime) + *stime += sdelta; +} + +void task_cputime_scaled(struct task_struct *t, + cputime_t *utimescaled, cputime_t *stimescaled) +{ + cputime_t udelta, sdelta; + + fetch_task_cputime(t, utimescaled, stimescaled, + &t->utimescaled, &t->stimescaled, &udelta, &sdelta); + if (utimescaled) + *utimescaled += cputime_to_scaled(udelta); + if (stimescaled) + *stimescaled += cputime_to_scaled(sdelta); +} +#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */ diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 7ae4c4c5420e..75024a673520 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -110,13 +110,6 @@ static char *task_group_path(struct task_group *tg) if (autogroup_path(tg, group_path, PATH_MAX)) return group_path; - /* - * May be NULL if the underlying cgroup isn't fully-created yet - */ - if (!tg->css.cgroup) { - group_path[0] = '\0'; - return group_path; - } cgroup_path(tg->css.cgroup, group_path, PATH_MAX); return group_path; } @@ -269,11 +262,11 @@ static void print_cpu(struct seq_file *m, int cpu) { unsigned int freq = cpu_khz ? : 1; - SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n", + SEQ_printf(m, "cpu#%d, %u.%03u MHz\n", cpu, freq / 1000, (freq % 1000)); } #else - SEQ_printf(m, "\ncpu#%d\n", cpu); + SEQ_printf(m, "cpu#%d\n", cpu); #endif #define P(x) \ @@ -330,6 +323,7 @@ do { \ print_rq(m, rq, cpu); rcu_read_unlock(); spin_unlock_irqrestore(&sched_debug_lock, flags); + SEQ_printf(m, "\n"); } static const char *sched_tunable_scaling_names[] = { @@ -338,11 +332,10 @@ static const char *sched_tunable_scaling_names[] = { "linear" }; -static int sched_debug_show(struct seq_file *m, void *v) +static void sched_debug_header(struct seq_file *m) { u64 ktime, sched_clk, cpu_clk; unsigned long flags; - int cpu; local_irq_save(flags); ktime = ktime_to_ns(ktime_get()); @@ -384,33 +377,101 @@ static int sched_debug_show(struct seq_file *m, void *v) #undef PN #undef P - SEQ_printf(m, " .%-40s: %d (%s)\n", "sysctl_sched_tunable_scaling", + SEQ_printf(m, " .%-40s: %d (%s)\n", + "sysctl_sched_tunable_scaling", sysctl_sched_tunable_scaling, sched_tunable_scaling_names[sysctl_sched_tunable_scaling]); + SEQ_printf(m, "\n"); +} - for_each_online_cpu(cpu) - print_cpu(m, cpu); +static int sched_debug_show(struct seq_file *m, void *v) +{ + int cpu = (unsigned long)(v - 2); - SEQ_printf(m, "\n"); + if (cpu != -1) + print_cpu(m, cpu); + else + sched_debug_header(m); return 0; } void sysrq_sched_debug_show(void) { - sched_debug_show(NULL, NULL); + int cpu; + + sched_debug_header(NULL); + for_each_online_cpu(cpu) + print_cpu(NULL, cpu); + +} + +/* + * This itererator needs some explanation. + * It returns 1 for the header position. + * This means 2 is cpu 0. + * In a hotplugged system some cpus, including cpu 0, may be missing so we have + * to use cpumask_* to iterate over the cpus. + */ +static void *sched_debug_start(struct seq_file *file, loff_t *offset) +{ + unsigned long n = *offset; + + if (n == 0) + return (void *) 1; + + n--; + + if (n > 0) + n = cpumask_next(n - 1, cpu_online_mask); + else + n = cpumask_first(cpu_online_mask); + + *offset = n + 1; + + if (n < nr_cpu_ids) + return (void *)(unsigned long)(n + 2); + return NULL; +} + +static void *sched_debug_next(struct seq_file *file, void *data, loff_t *offset) +{ + (*offset)++; + return sched_debug_start(file, offset); +} + +static void sched_debug_stop(struct seq_file *file, void *data) +{ +} + +static const struct seq_operations sched_debug_sops = { + .start = sched_debug_start, + .next = sched_debug_next, + .stop = sched_debug_stop, + .show = sched_debug_show, +}; + +static int sched_debug_release(struct inode *inode, struct file *file) +{ + seq_release(inode, file); + + return 0; } static int sched_debug_open(struct inode *inode, struct file *filp) { - return single_open(filp, sched_debug_show, NULL); + int ret = 0; + + ret = seq_open(filp, &sched_debug_sops); + + return ret; } static const struct file_operations sched_debug_fops = { .open = sched_debug_open, .read = seq_read, .llseek = seq_lseek, - .release = single_release, + .release = sched_debug_release, }; static int __init init_sched_debug_procfs(void) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 81fa53643409..c61a614465c8 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -431,13 +431,13 @@ void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, unsigned long delta_exec); * Scheduling class tree data structure manipulation methods: */ -static inline u64 max_vruntime(u64 min_vruntime, u64 vruntime) +static inline u64 max_vruntime(u64 max_vruntime, u64 vruntime) { - s64 delta = (s64)(vruntime - min_vruntime); + s64 delta = (s64)(vruntime - max_vruntime); if (delta > 0) - min_vruntime = vruntime; + max_vruntime = vruntime; - return min_vruntime; + return max_vruntime; } static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime) @@ -473,6 +473,7 @@ static void update_min_vruntime(struct cfs_rq *cfs_rq) vruntime = min_vruntime(vruntime, se->vruntime); } + /* ensure we never gain time by being placed backwards. */ cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime); #ifndef CONFIG_64BIT smp_wmb(); @@ -652,7 +653,7 @@ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) } /* - * We calculate the vruntime slice of a to be inserted task + * We calculate the vruntime slice of a to-be-inserted task. * * vs = s/w */ @@ -1562,6 +1563,27 @@ static inline void dequeue_entity_load_avg(struct cfs_rq *cfs_rq, se->avg.decay_count = atomic64_read(&cfs_rq->decay_counter); } /* migrations, e.g. sleep=0 leave decay_count == 0 */ } + +/* + * Update the rq's load with the elapsed running time before entering + * idle. if the last scheduled task is not a CFS task, idle_enter will + * be the only way to update the runnable statistic. + */ +void idle_enter_fair(struct rq *this_rq) +{ + update_rq_runnable_avg(this_rq, 1); +} + +/* + * Update the rq's load with the elapsed idle time before a task is + * scheduled. if the newly scheduled task is not a CFS task, idle_exit will + * be the only way to update the runnable statistic. + */ +void idle_exit_fair(struct rq *this_rq) +{ + update_rq_runnable_avg(this_rq, 0); +} + #else static inline void update_entity_load_avg(struct sched_entity *se, int update_cfs_rq) {} @@ -1680,9 +1702,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) } /* ensure we never gain time by being placed backwards. */ - vruntime = max_vruntime(se->vruntime, vruntime); - - se->vruntime = vruntime; + se->vruntime = max_vruntime(se->vruntime, vruntime); } static void check_enqueue_throttle(struct cfs_rq *cfs_rq); @@ -3254,25 +3274,18 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) */ static int select_idle_sibling(struct task_struct *p, int target) { - int cpu = smp_processor_id(); - int prev_cpu = task_cpu(p); struct sched_domain *sd; struct sched_group *sg; - int i; + int i = task_cpu(p); - /* - * If the task is going to be woken-up on this cpu and if it is - * already idle, then it is the right target. - */ - if (target == cpu && idle_cpu(cpu)) - return cpu; + if (idle_cpu(target)) + return target; /* - * If the task is going to be woken-up on the cpu where it previously - * ran and if it is currently idle, then it the right target. + * If the prevous cpu is cache affine and idle, don't be stupid. */ - if (target == prev_cpu && idle_cpu(prev_cpu)) - return prev_cpu; + if (i != target && cpus_share_cache(i, target) && idle_cpu(i)) + return i; /* * Otherwise, iterate the domains and find an elegible idle cpu. @@ -3286,7 +3299,7 @@ static int select_idle_sibling(struct task_struct *p, int target) goto next; for_each_cpu(i, sched_group_cpus(sg)) { - if (!idle_cpu(i)) + if (i == target || !idle_cpu(i)) goto next; } @@ -3883,12 +3896,16 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) int tsk_cache_hot = 0; /* * We do not migrate tasks that are: - * 1) running (obviously), or + * 1) throttled_lb_pair, or * 2) cannot be migrated to this CPU due to cpus_allowed, or - * 3) are cache-hot on their current CPU. + * 3) running (obviously), or + * 4) are cache-hot on their current CPU. */ + if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu)) + return 0; + if (!cpumask_test_cpu(env->dst_cpu, tsk_cpus_allowed(p))) { - int new_dst_cpu; + int cpu; schedstat_inc(p, se.statistics.nr_failed_migrations_affine); @@ -3903,12 +3920,15 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) if (!env->dst_grpmask || (env->flags & LBF_SOME_PINNED)) return 0; - new_dst_cpu = cpumask_first_and(env->dst_grpmask, - tsk_cpus_allowed(p)); - if (new_dst_cpu < nr_cpu_ids) { - env->flags |= LBF_SOME_PINNED; - env->new_dst_cpu = new_dst_cpu; + /* Prevent to re-select dst_cpu via env's cpus */ + for_each_cpu_and(cpu, env->dst_grpmask, env->cpus) { + if (cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) { + env->flags |= LBF_SOME_PINNED; + env->new_dst_cpu = cpu; + break; + } } + return 0; } @@ -3929,20 +3949,17 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) tsk_cache_hot = task_hot(p, env->src_rq->clock_task, env->sd); if (!tsk_cache_hot || env->sd->nr_balance_failed > env->sd->cache_nice_tries) { -#ifdef CONFIG_SCHEDSTATS + if (tsk_cache_hot) { schedstat_inc(env->sd, lb_hot_gained[env->idle]); schedstat_inc(p, se.statistics.nr_forced_migrations); } -#endif + return 1; } - if (tsk_cache_hot) { - schedstat_inc(p, se.statistics.nr_failed_migrations_hot); - return 0; - } - return 1; + schedstat_inc(p, se.statistics.nr_failed_migrations_hot); + return 0; } /* @@ -3957,9 +3974,6 @@ static int move_one_task(struct lb_env *env) struct task_struct *p, *n; list_for_each_entry_safe(p, n, &env->src_rq->cfs_tasks, se.group_node) { - if (throttled_lb_pair(task_group(p), env->src_rq->cpu, env->dst_cpu)) - continue; - if (!can_migrate_task(p, env)) continue; @@ -4011,7 +4025,7 @@ static int move_tasks(struct lb_env *env) break; } - if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu)) + if (!can_migrate_task(p, env)) goto next; load = task_h_load(p); @@ -4022,9 +4036,6 @@ static int move_tasks(struct lb_env *env) if ((load / 2) > env->imbalance) goto next; - if (!can_migrate_task(p, env)) - goto next; - move_task(p, env); pulled++; env->imbalance -= load; @@ -4254,7 +4265,7 @@ static inline int get_sd_load_idx(struct sched_domain *sd, return load_idx; } -unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu) +static unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu) { return SCHED_POWER_SCALE; } @@ -4264,7 +4275,7 @@ unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu) return default_scale_freq_power(sd, cpu); } -unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu) +static unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu) { unsigned long weight = sd->span_weight; unsigned long smt_gain = sd->smt_gain; @@ -4279,7 +4290,7 @@ unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu) return default_scale_smt_power(sd, cpu); } -unsigned long scale_rt_power(int cpu) +static unsigned long scale_rt_power(int cpu) { struct rq *rq = cpu_rq(cpu); u64 total, available, age_stamp, avg; @@ -4969,7 +4980,7 @@ static struct rq *find_busiest_queue(struct lb_env *env, #define MAX_PINNED_INTERVAL 512 /* Working cpumask for load_balance and load_balance_newidle. */ -DEFINE_PER_CPU(cpumask_var_t, load_balance_tmpmask); +DEFINE_PER_CPU(cpumask_var_t, load_balance_mask); static int need_active_balance(struct lb_env *env) { @@ -5000,11 +5011,10 @@ static int load_balance(int this_cpu, struct rq *this_rq, int *balance) { int ld_moved, cur_ld_moved, active_balance = 0; - int lb_iterations, max_lb_iterations; struct sched_group *group; struct rq *busiest; unsigned long flags; - struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); + struct cpumask *cpus = __get_cpu_var(load_balance_mask); struct lb_env env = { .sd = sd, @@ -5016,8 +5026,14 @@ static int load_balance(int this_cpu, struct rq *this_rq, .cpus = cpus, }; + /* + * For NEWLY_IDLE load_balancing, we don't need to consider + * other cpus in our group + */ + if (idle == CPU_NEWLY_IDLE) + env.dst_grpmask = NULL; + cpumask_copy(cpus, cpu_active_mask); - max_lb_iterations = cpumask_weight(env.dst_grpmask); schedstat_inc(sd, lb_count[idle]); @@ -5043,7 +5059,6 @@ redo: schedstat_add(sd, lb_imbalance[idle], env.imbalance); ld_moved = 0; - lb_iterations = 1; if (busiest->nr_running > 1) { /* * Attempt to move tasks. If find_busiest_group has found @@ -5070,17 +5085,17 @@ more_balance: double_rq_unlock(env.dst_rq, busiest); local_irq_restore(flags); - if (env.flags & LBF_NEED_BREAK) { - env.flags &= ~LBF_NEED_BREAK; - goto more_balance; - } - /* * some other cpu did the load balance for us. */ if (cur_ld_moved && env.dst_cpu != smp_processor_id()) resched_cpu(env.dst_cpu); + if (env.flags & LBF_NEED_BREAK) { + env.flags &= ~LBF_NEED_BREAK; + goto more_balance; + } + /* * Revisit (affine) tasks on src_cpu that couldn't be moved to * us and move them to an alternate dst_cpu in our sched_group @@ -5100,14 +5115,17 @@ more_balance: * moreover subsequent load balance cycles should correct the * excess load moved. */ - if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0 && - lb_iterations++ < max_lb_iterations) { + if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) { env.dst_rq = cpu_rq(env.new_dst_cpu); env.dst_cpu = env.new_dst_cpu; env.flags &= ~LBF_SOME_PINNED; env.loop = 0; env.loop_break = sched_nr_migrate_break; + + /* Prevent to re-select dst_cpu via env's cpus */ + cpumask_clear_cpu(env.dst_cpu, env.cpus); + /* * Go back to "more_balance" rather than "redo" since we * need to continue with same src_cpu. @@ -5228,8 +5246,6 @@ void idle_balance(int this_cpu, struct rq *this_rq) if (this_rq->avg_idle < sysctl_sched_migration_cost) return; - update_rq_runnable_avg(this_rq, 1); - /* * Drop the rq->lock, but keep IRQ/preempt disabled. */ @@ -5339,7 +5355,7 @@ out_unlock: return 0; } -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON /* * idle load balancing details * - When one of the busy CPUs notice that there may be an idle rebalancing @@ -5404,13 +5420,16 @@ static inline void set_cpu_sd_state_busy(void) struct sched_domain *sd; int cpu = smp_processor_id(); - if (!test_bit(NOHZ_IDLE, nohz_flags(cpu))) - return; - clear_bit(NOHZ_IDLE, nohz_flags(cpu)); - rcu_read_lock(); - for_each_domain(cpu, sd) + sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); + + if (!sd || !sd->nohz_idle) + goto unlock; + sd->nohz_idle = 0; + + for (; sd; sd = sd->parent) atomic_inc(&sd->groups->sgp->nr_busy_cpus); +unlock: rcu_read_unlock(); } @@ -5419,13 +5438,16 @@ void set_cpu_sd_state_idle(void) struct sched_domain *sd; int cpu = smp_processor_id(); - if (test_bit(NOHZ_IDLE, nohz_flags(cpu))) - return; - set_bit(NOHZ_IDLE, nohz_flags(cpu)); - rcu_read_lock(); - for_each_domain(cpu, sd) + sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); + + if (!sd || sd->nohz_idle) + goto unlock; + sd->nohz_idle = 1; + + for (; sd; sd = sd->parent) atomic_dec(&sd->groups->sgp->nr_busy_cpus); +unlock: rcu_read_unlock(); } @@ -5477,7 +5499,7 @@ void update_max_interval(void) * It checks each scheduling domain to see if it is due to be balanced, * and initiates a balancing operation if so. * - * Balancing parameters are set up in arch_init_sched_domains. + * Balancing parameters are set up in init_sched_domains. */ static void rebalance_domains(int cpu, enum cpu_idle_type idle) { @@ -5515,10 +5537,11 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle) if (time_after_eq(jiffies, sd->last_balance + interval)) { if (load_balance(cpu, rq, sd, idle, &balance)) { /* - * We've pulled tasks over so either we're no - * longer idle. + * The LBF_SOME_PINNED logic could have changed + * env->dst_cpu, so we can't know our idle + * state even if we migrated tasks. Update it. */ - idle = CPU_NOT_IDLE; + idle = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE; } sd->last_balance = jiffies; } @@ -5549,9 +5572,9 @@ out: rq->next_balance = next_balance; } -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON /* - * In CONFIG_NO_HZ case, the idle balance kickee will do the + * In CONFIG_NO_HZ_COMMON case, the idle balance kickee will do the * rebalancing for all the cpus for whom scheduler ticks are stopped. */ static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle) @@ -5694,7 +5717,7 @@ void trigger_load_balance(struct rq *rq, int cpu) if (time_after_eq(jiffies, rq->next_balance) && likely(!on_null_domain(cpu))) raise_softirq(SCHED_SOFTIRQ); -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON if (nohz_kick_needed(rq, cpu) && likely(!on_null_domain(cpu))) nohz_balancer_kick(cpu); #endif @@ -6101,7 +6124,7 @@ static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task * idle runqueue: */ if (rq->cfs.load.weight) - rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); + rr_interval = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se)); return rr_interval; } @@ -6164,7 +6187,7 @@ __init void init_sched_fair_class(void) #ifdef CONFIG_SMP open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON nohz.next_balance = jiffies; zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT); cpu_notifier(sched_ilb_notifier, 0); diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 1ad1d2b5395f..99399f8e4799 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -46,13 +46,6 @@ SCHED_FEAT(DOUBLE_TICK, false) SCHED_FEAT(LB_BIAS, true) /* - * Spin-wait on mutex acquisition when the mutex owner is running on - * another cpu -- assumes that when the owner is running, it will soon - * release the lock. Decreases scheduling overhead. - */ -SCHED_FEAT(OWNER_SPIN, true) - -/* * Decrement CPU power based on time not spent running tasks */ SCHED_FEAT(NONTASK_POWER, true) diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c index b6baf370cae9..d8da01008d39 100644 --- a/kernel/sched/idle_task.c +++ b/kernel/sched/idle_task.c @@ -13,6 +13,17 @@ select_task_rq_idle(struct task_struct *p, int sd_flag, int flags) { return task_cpu(p); /* IDLE tasks as never migrated */ } + +static void pre_schedule_idle(struct rq *rq, struct task_struct *prev) +{ + idle_exit_fair(rq); + rq_last_tick_reset(rq); +} + +static void post_schedule_idle(struct rq *rq) +{ + idle_enter_fair(rq); +} #endif /* CONFIG_SMP */ /* * Idle tasks are unconditionally rescheduled: @@ -25,6 +36,10 @@ static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int fl static struct task_struct *pick_next_task_idle(struct rq *rq) { schedstat_inc(rq, sched_goidle); +#ifdef CONFIG_SMP + /* Trigger the post schedule to do an idle_enter for CFS */ + rq->post_schedule = 1; +#endif return rq->idle; } @@ -86,6 +101,8 @@ const struct sched_class idle_sched_class = { #ifdef CONFIG_SMP .select_task_rq = select_task_rq_idle, + .pre_schedule = pre_schedule_idle, + .post_schedule = post_schedule_idle, #endif .set_curr_task = set_curr_task_idle, diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 4f02b2847357..127a2c4cf4ab 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -7,6 +7,8 @@ #include <linux/slab.h> +int sched_rr_timeslice = RR_TIMESLICE; + static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); struct rt_bandwidth def_rt_bandwidth; @@ -925,8 +927,8 @@ static void update_curr_rt(struct rq *rq) return; delta_exec = rq->clock_task - curr->se.exec_start; - if (unlikely((s64)delta_exec < 0)) - delta_exec = 0; + if (unlikely((s64)delta_exec <= 0)) + return; schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec)); @@ -1427,8 +1429,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p) static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) { if (!task_running(rq, p) && - (cpu < 0 || cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) && - (p->nr_cpus_allowed > 1)) + cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) return 1; return 0; } @@ -1889,8 +1890,11 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p) * we may need to handle the pulling of RT tasks * now. */ - if (p->on_rq && !rq->rt.rt_nr_running) - pull_rt_task(rq); + if (!p->on_rq || rq->rt.rt_nr_running) + return; + + if (pull_rt_task(rq)) + resched_task(rq->curr); } void init_sched_rt_class(void) @@ -1985,7 +1989,11 @@ static void watchdog(struct rq *rq, struct task_struct *p) if (soft != RLIM_INFINITY) { unsigned long next; - p->rt.timeout++; + if (p->rt.watchdog_stamp != jiffies) { + p->rt.timeout++; + p->rt.watchdog_stamp = jiffies; + } + next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); if (p->rt.timeout > next) p->cputime_expires.sched_exp = p->se.sum_exec_runtime; @@ -2010,7 +2018,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) if (--p->rt.time_slice) return; - p->rt.time_slice = RR_TIMESLICE; + p->rt.time_slice = sched_rr_timeslice; /* * Requeue to the end of queue if we (and all of our ancestors) are the @@ -2041,7 +2049,7 @@ static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) * Time slice is 0 for SCHED_FIFO tasks */ if (task->policy == SCHED_RR) - return RR_TIMESLICE; + return sched_rr_timeslice; else return 0; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index fc886441436a..ce39224d6155 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1,10 +1,14 @@ #include <linux/sched.h> +#include <linux/sched/sysctl.h> +#include <linux/sched/rt.h> #include <linux/mutex.h> #include <linux/spinlock.h> #include <linux/stop_machine.h> +#include <linux/tick.h> #include "cpupri.h" +#include "cpuacct.h" extern __read_mostly int scheduler_running; @@ -31,6 +35,31 @@ extern __read_mostly int scheduler_running; */ #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) +/* + * Increase resolution of nice-level calculations for 64-bit architectures. + * The extra resolution improves shares distribution and load balancing of + * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup + * hierarchies, especially on larger systems. This is not a user-visible change + * and does not change the user-interface for setting shares/weights. + * + * We increase resolution only if we have enough bits to allow this increased + * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution + * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the + * increased costs. + */ +#if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */ +# define SCHED_LOAD_RESOLUTION 10 +# define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION) +# define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION) +#else +# define SCHED_LOAD_RESOLUTION 0 +# define scale_load(w) (w) +# define scale_load_down(w) (w) +#endif + +#define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION) +#define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT) + #define NICE_0_LOAD SCHED_LOAD_SCALE #define NICE_0_SHIFT SCHED_LOAD_SHIFT @@ -152,11 +181,6 @@ struct task_group { #define MAX_SHARES (1UL << 18) #endif -/* Default task group. - * Every task in system belong to this group at bootup. - */ -extern struct task_group root_task_group; - typedef int (*tg_visitor)(struct task_group *, void *); extern int walk_tg_tree_from(struct task_group *from, @@ -194,6 +218,18 @@ extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int cpu, struct sched_rt_entity *parent); +extern struct task_group *sched_create_group(struct task_group *parent); +extern void sched_online_group(struct task_group *tg, + struct task_group *parent); +extern void sched_destroy_group(struct task_group *tg); +extern void sched_offline_group(struct task_group *tg); + +extern void sched_move_task(struct task_struct *tsk); + +#ifdef CONFIG_FAIR_GROUP_SCHED +extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); +#endif + #else /* CONFIG_CGROUP_SCHED */ struct cfs_bandwidth { }; @@ -370,10 +406,13 @@ struct rq { #define CPU_LOAD_IDX_MAX 5 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; unsigned long last_load_update_tick; -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON u64 nohz_stamp; unsigned long nohz_flags; #endif +#ifdef CONFIG_NO_HZ_FULL + unsigned long last_sched_tick; +#endif int skip_clock_update; /* capture load from *all* tasks on this cpu: */ @@ -545,6 +584,62 @@ static inline struct sched_domain *highest_flag_domain(int cpu, int flag) DECLARE_PER_CPU(struct sched_domain *, sd_llc); DECLARE_PER_CPU(int, sd_llc_id); +struct sched_group_power { + atomic_t ref; + /* + * CPU power of this group, SCHED_LOAD_SCALE being max power for a + * single CPU. + */ + unsigned int power, power_orig; + unsigned long next_update; + /* + * Number of busy cpus in this group. + */ + atomic_t nr_busy_cpus; + + unsigned long cpumask[0]; /* iteration mask */ +}; + +struct sched_group { + struct sched_group *next; /* Must be a circular list */ + atomic_t ref; + + unsigned int group_weight; + struct sched_group_power *sgp; + + /* + * The CPUs this group covers. + * + * NOTE: this field is variable length. (Allocated dynamically + * by attaching extra space to the end of the structure, + * depending on how many CPUs the kernel has booted up with) + */ + unsigned long cpumask[0]; +}; + +static inline struct cpumask *sched_group_cpus(struct sched_group *sg) +{ + return to_cpumask(sg->cpumask); +} + +/* + * cpumask masking which cpus in the group are allowed to iterate up the domain + * tree. + */ +static inline struct cpumask *sched_group_mask(struct sched_group *sg) +{ + return to_cpumask(sg->sgp->cpumask); +} + +/** + * group_first_cpu - Returns the first cpu in the cpumask of a sched_group. + * @group: The group whose first cpu is to be returned. + */ +static inline unsigned int group_first_cpu(struct sched_group *group) +{ + return cpumask_first(sched_group_cpus(group)); +} + extern int group_balance_cpu(struct sched_group *sg); #endif /* CONFIG_SMP */ @@ -782,6 +877,12 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) } #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ +/* + * wake flags + */ +#define WF_SYNC 0x01 /* waker goes to sleep after wakeup */ +#define WF_FORK 0x02 /* child wakeup after fork */ +#define WF_MIGRATED 0x4 /* internal use, task got migrated */ static inline void update_load_add(struct load_weight *lw, unsigned long inc) { @@ -854,14 +955,61 @@ static const u32 prio_to_wmult[40] = { /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, }; -/* Time spent by the tasks of the cpu accounting group executing in ... */ -enum cpuacct_stat_index { - CPUACCT_STAT_USER, /* ... user mode */ - CPUACCT_STAT_SYSTEM, /* ... kernel mode */ +#define ENQUEUE_WAKEUP 1 +#define ENQUEUE_HEAD 2 +#ifdef CONFIG_SMP +#define ENQUEUE_WAKING 4 /* sched_class::task_waking was called */ +#else +#define ENQUEUE_WAKING 0 +#endif - CPUACCT_STAT_NSTATS, -}; +#define DEQUEUE_SLEEP 1 +struct sched_class { + const struct sched_class *next; + + void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); + void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); + void (*yield_task) (struct rq *rq); + bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt); + + void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags); + + struct task_struct * (*pick_next_task) (struct rq *rq); + void (*put_prev_task) (struct rq *rq, struct task_struct *p); + +#ifdef CONFIG_SMP + int (*select_task_rq)(struct task_struct *p, int sd_flag, int flags); + void (*migrate_task_rq)(struct task_struct *p, int next_cpu); + + void (*pre_schedule) (struct rq *this_rq, struct task_struct *task); + void (*post_schedule) (struct rq *this_rq); + void (*task_waking) (struct task_struct *task); + void (*task_woken) (struct rq *this_rq, struct task_struct *task); + + void (*set_cpus_allowed)(struct task_struct *p, + const struct cpumask *newmask); + + void (*rq_online)(struct rq *rq); + void (*rq_offline)(struct rq *rq); +#endif + + void (*set_curr_task) (struct rq *rq); + void (*task_tick) (struct rq *rq, struct task_struct *p, int queued); + void (*task_fork) (struct task_struct *p); + + void (*switched_from) (struct rq *this_rq, struct task_struct *task); + void (*switched_to) (struct rq *this_rq, struct task_struct *task); + void (*prio_changed) (struct rq *this_rq, struct task_struct *task, + int oldprio); + + unsigned int (*get_rr_interval) (struct rq *rq, + struct task_struct *task); + +#ifdef CONFIG_FAIR_GROUP_SCHED + void (*task_move_group) (struct task_struct *p, int on_rq); +#endif +}; #define sched_class_highest (&stop_sched_class) #define for_each_class(class) \ @@ -875,9 +1023,23 @@ extern const struct sched_class idle_sched_class; #ifdef CONFIG_SMP +extern void update_group_power(struct sched_domain *sd, int cpu); + extern void trigger_load_balance(struct rq *rq, int cpu); extern void idle_balance(int this_cpu, struct rq *this_rq); +/* + * Only depends on SMP, FAIR_GROUP_SCHED may be removed when runnable_avg + * becomes useful in lb + */ +#if defined(CONFIG_FAIR_GROUP_SCHED) +extern void idle_enter_fair(struct rq *this_rq); +extern void idle_exit_fair(struct rq *this_rq); +#else +static inline void idle_enter_fair(struct rq *this_rq) {} +static inline void idle_exit_fair(struct rq *this_rq) {} +#endif + #else /* CONFIG_SMP */ static inline void idle_balance(int cpu, struct rq *rq) @@ -889,7 +1051,6 @@ static inline void idle_balance(int cpu, struct rq *rq) extern void sysrq_sched_debug_show(void); extern void sched_init_granularity(void); extern void update_max_interval(void); -extern void update_group_power(struct sched_domain *sd, int cpu); extern int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu); extern void init_sched_rt_class(void); extern void init_sched_fair_class(void); @@ -902,45 +1063,6 @@ extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime extern void update_idle_cpu_load(struct rq *this_rq); -#ifdef CONFIG_CGROUP_CPUACCT -#include <linux/cgroup.h> -/* track cpu usage of a group of tasks and its child groups */ -struct cpuacct { - struct cgroup_subsys_state css; - /* cpuusage holds pointer to a u64-type object on every cpu */ - u64 __percpu *cpuusage; - struct kernel_cpustat __percpu *cpustat; -}; - -extern struct cgroup_subsys cpuacct_subsys; -extern struct cpuacct root_cpuacct; - -/* return cpu accounting group corresponding to this container */ -static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) -{ - return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), - struct cpuacct, css); -} - -/* return cpu accounting group to which this task belongs */ -static inline struct cpuacct *task_ca(struct task_struct *tsk) -{ - return container_of(task_subsys_state(tsk, cpuacct_subsys_id), - struct cpuacct, css); -} - -static inline struct cpuacct *parent_ca(struct cpuacct *ca) -{ - if (!ca || !ca->css.cgroup->parent) - return NULL; - return cgroup_ca(ca->css.cgroup->parent); -} - -extern void cpuacct_charge(struct task_struct *tsk, u64 cputime); -#else -static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} -#endif - #ifdef CONFIG_PARAVIRT static inline u64 steal_ticks(u64 steal) { @@ -954,6 +1076,16 @@ static inline u64 steal_ticks(u64 steal) static inline void inc_nr_running(struct rq *rq) { rq->nr_running++; + +#ifdef CONFIG_NO_HZ_FULL + if (rq->nr_running == 2) { + if (tick_nohz_full_cpu(rq->cpu)) { + /* Order rq->nr_running write against the IPI */ + smp_wmb(); + smp_send_reschedule(rq->cpu); + } + } +#endif } static inline void dec_nr_running(struct rq *rq) @@ -961,6 +1093,13 @@ static inline void dec_nr_running(struct rq *rq) rq->nr_running--; } +static inline void rq_last_tick_reset(struct rq *rq) +{ +#ifdef CONFIG_NO_HZ_FULL + rq->last_sched_tick = jiffies; +#endif +} + extern void update_rq_clock(struct rq *rq); extern void activate_task(struct rq *rq, struct task_struct *p, int flags); @@ -1181,11 +1320,10 @@ extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq); extern void account_cfs_bandwidth_used(int enabled, int was_enabled); -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON enum rq_nohz_flag_bits { NOHZ_TICK_STOPPED, NOHZ_BALANCE_KICK, - NOHZ_IDLE, }; #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c index 903ffa9e8872..da98af347e8b 100644 --- a/kernel/sched/stats.c +++ b/kernel/sched/stats.c @@ -21,14 +21,17 @@ static int show_schedstat(struct seq_file *seq, void *v) if (mask_str == NULL) return -ENOMEM; - seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION); - seq_printf(seq, "timestamp %lu\n", jiffies); - for_each_online_cpu(cpu) { - struct rq *rq = cpu_rq(cpu); + if (v == (void *)1) { + seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION); + seq_printf(seq, "timestamp %lu\n", jiffies); + } else { + struct rq *rq; #ifdef CONFIG_SMP struct sched_domain *sd; int dcount = 0; #endif + cpu = (unsigned long)(v - 2); + rq = cpu_rq(cpu); /* runqueue-specific stats */ seq_printf(seq, @@ -77,30 +80,61 @@ static int show_schedstat(struct seq_file *seq, void *v) return 0; } -static int schedstat_open(struct inode *inode, struct file *file) +/* + * This itererator needs some explanation. + * It returns 1 for the header position. + * This means 2 is cpu 0. + * In a hotplugged system some cpus, including cpu 0, may be missing so we have + * to use cpumask_* to iterate over the cpus. + */ +static void *schedstat_start(struct seq_file *file, loff_t *offset) { - unsigned int size = PAGE_SIZE * (1 + num_online_cpus() / 32); - char *buf = kmalloc(size, GFP_KERNEL); - struct seq_file *m; - int res; + unsigned long n = *offset; - if (!buf) - return -ENOMEM; - res = single_open(file, show_schedstat, NULL); - if (!res) { - m = file->private_data; - m->buf = buf; - m->size = size; - } else - kfree(buf); - return res; + if (n == 0) + return (void *) 1; + + n--; + + if (n > 0) + n = cpumask_next(n - 1, cpu_online_mask); + else + n = cpumask_first(cpu_online_mask); + + *offset = n + 1; + + if (n < nr_cpu_ids) + return (void *)(unsigned long)(n + 2); + return NULL; +} + +static void *schedstat_next(struct seq_file *file, void *data, loff_t *offset) +{ + (*offset)++; + return schedstat_start(file, offset); +} + +static void schedstat_stop(struct seq_file *file, void *data) +{ +} + +static const struct seq_operations schedstat_sops = { + .start = schedstat_start, + .next = schedstat_next, + .stop = schedstat_stop, + .show = show_schedstat, +}; + +static int schedstat_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &schedstat_sops); } static const struct file_operations proc_schedstat_operations = { .open = schedstat_open, .read = seq_read, .llseek = seq_lseek, - .release = single_release, + .release = seq_release, }; static int __init proc_schedstat_init(void) diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 5af44b593770..b7a10048a32c 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -160,6 +160,8 @@ static int seccomp_check_filter(struct sock_filter *filter, unsigned int flen) case BPF_S_ALU_AND_X: case BPF_S_ALU_OR_K: case BPF_S_ALU_OR_X: + case BPF_S_ALU_XOR_K: + case BPF_S_ALU_XOR_X: case BPF_S_ALU_LSH_K: case BPF_S_ALU_LSH_X: case BPF_S_ALU_RSH_K: diff --git a/kernel/semaphore.c b/kernel/semaphore.c index 4567fc020fe3..6815171a4fff 100644 --- a/kernel/semaphore.c +++ b/kernel/semaphore.c @@ -193,7 +193,7 @@ EXPORT_SYMBOL(up); struct semaphore_waiter { struct list_head list; struct task_struct *task; - int up; + bool up; }; /* @@ -209,12 +209,12 @@ static inline int __sched __down_common(struct semaphore *sem, long state, list_add_tail(&waiter.list, &sem->wait_list); waiter.task = task; - waiter.up = 0; + waiter.up = false; for (;;) { if (signal_pending_state(state, task)) goto interrupted; - if (timeout <= 0) + if (unlikely(timeout <= 0)) goto timed_out; __set_task_state(task, state); raw_spin_unlock_irq(&sem->lock); @@ -258,6 +258,6 @@ static noinline void __sched __up(struct semaphore *sem) struct semaphore_waiter *waiter = list_first_entry(&sem->wait_list, struct semaphore_waiter, list); list_del(&waiter->list); - waiter->up = 1; + waiter->up = true; wake_up_process(waiter->task); } diff --git a/kernel/signal.c b/kernel/signal.c index 3d09cf6cde75..113411bfe8b1 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -32,6 +32,7 @@ #include <linux/user_namespace.h> #include <linux/uprobes.h> #include <linux/compat.h> +#include <linux/cn_proc.h> #define CREATE_TRACE_POINTS #include <trace/events/signal.h> @@ -485,6 +486,9 @@ flush_signal_handlers(struct task_struct *t, int force_default) if (force_default || ka->sa.sa_handler != SIG_IGN) ka->sa.sa_handler = SIG_DFL; ka->sa.sa_flags = 0; +#ifdef __ARCH_HAS_SA_RESTORER + ka->sa.sa_restorer = NULL; +#endif sigemptyset(&ka->sa.sa_mask); ka++; } @@ -851,12 +855,14 @@ static void ptrace_trap_notify(struct task_struct *t) * Returns true if the signal should be actually delivered, otherwise * it should be dropped. */ -static int prepare_signal(int sig, struct task_struct *p, bool force) +static bool prepare_signal(int sig, struct task_struct *p, bool force) { struct signal_struct *signal = p->signal; struct task_struct *t; - if (unlikely(signal->flags & SIGNAL_GROUP_EXIT)) { + if (signal->flags & (SIGNAL_GROUP_EXIT | SIGNAL_GROUP_COREDUMP)) { + if (signal->flags & SIGNAL_GROUP_COREDUMP) + return sig == SIGKILL; /* * The process is in the middle of dying, nothing to do. */ @@ -1157,11 +1163,10 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t, static void print_fatal_signal(int signr) { struct pt_regs *regs = signal_pt_regs(); - printk("%s/%d: potentially unexpected fatal signal %d.\n", - current->comm, task_pid_nr(current), signr); + printk(KERN_INFO "potentially unexpected fatal signal %d.\n", signr); #if defined(__i386__) && !defined(__arch_um__) - printk("code at %08lx: ", regs->ip); + printk(KERN_INFO "code at %08lx: ", regs->ip); { int i; for (i = 0; i < 16; i++) { @@ -1169,11 +1174,11 @@ static void print_fatal_signal(int signr) if (get_user(insn, (unsigned char *)(regs->ip + i))) break; - printk("%02x ", insn); + printk(KERN_CONT "%02x ", insn); } } + printk(KERN_CONT "\n"); #endif - printk("\n"); preempt_disable(); show_regs(regs); preempt_enable(); @@ -1632,6 +1637,7 @@ bool do_notify_parent(struct task_struct *tsk, int sig) unsigned long flags; struct sighand_struct *psig; bool autoreap = false; + cputime_t utime, stime; BUG_ON(sig == -1); @@ -1669,8 +1675,9 @@ bool do_notify_parent(struct task_struct *tsk, int sig) task_uid(tsk)); rcu_read_unlock(); - info.si_utime = cputime_to_clock_t(tsk->utime + tsk->signal->utime); - info.si_stime = cputime_to_clock_t(tsk->stime + tsk->signal->stime); + task_cputime(tsk, &utime, &stime); + info.si_utime = cputime_to_clock_t(utime + tsk->signal->utime); + info.si_stime = cputime_to_clock_t(stime + tsk->signal->stime); info.si_status = tsk->exit_code & 0x7f; if (tsk->exit_code & 0x80) @@ -1734,6 +1741,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, unsigned long flags; struct task_struct *parent; struct sighand_struct *sighand; + cputime_t utime, stime; if (for_ptracer) { parent = tsk->parent; @@ -1752,8 +1760,9 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk)); rcu_read_unlock(); - info.si_utime = cputime_to_clock_t(tsk->utime); - info.si_stime = cputime_to_clock_t(tsk->stime); + task_cputime(tsk, &utime, &stime); + info.si_utime = cputime_to_clock_t(utime); + info.si_stime = cputime_to_clock_t(stime); info.si_code = why; switch (why) { @@ -2343,6 +2352,7 @@ relock: if (sig_kernel_coredump(signr)) { if (print_fatal_signals) print_fatal_signal(info->si_signo); + proc_coredump_connector(current); /* * If it was able to dump core, this kills all * other threads in the group and synchronizes with @@ -2395,6 +2405,15 @@ void signal_delivered(int sig, siginfo_t *info, struct k_sigaction *ka, tracehook_signal_handler(sig, info, ka, regs, stepping); } +void signal_setup_done(int failed, struct ksignal *ksig, int stepping) +{ + if (failed) + force_sigsegv(ksig->sig, current); + else + signal_delivered(ksig->sig, &ksig->info, &ksig->ka, + signal_pt_regs(), stepping); +} + /* * It could be that complete_signal() picked us to notify about the * group-wide signal. Other threads should be notified now to take @@ -2612,40 +2631,95 @@ SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset, return 0; } -long do_sigpending(void __user *set, unsigned long sigsetsize) +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset, + compat_sigset_t __user *, oset, compat_size_t, sigsetsize) { - long error = -EINVAL; - sigset_t pending; +#ifdef __BIG_ENDIAN + sigset_t old_set = current->blocked; + + /* XXX: Don't preclude handling different sized sigset_t's. */ + if (sigsetsize != sizeof(sigset_t)) + return -EINVAL; + + if (nset) { + compat_sigset_t new32; + sigset_t new_set; + int error; + if (copy_from_user(&new32, nset, sizeof(compat_sigset_t))) + return -EFAULT; + + sigset_from_compat(&new_set, &new32); + sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); + + error = sigprocmask(how, &new_set, NULL); + if (error) + return error; + } + if (oset) { + compat_sigset_t old32; + sigset_to_compat(&old32, &old_set); + if (copy_to_user(oset, &old32, sizeof(compat_sigset_t))) + return -EFAULT; + } + return 0; +#else + return sys_rt_sigprocmask(how, (sigset_t __user *)nset, + (sigset_t __user *)oset, sigsetsize); +#endif +} +#endif +static int do_sigpending(void *set, unsigned long sigsetsize) +{ if (sigsetsize > sizeof(sigset_t)) - goto out; + return -EINVAL; spin_lock_irq(¤t->sighand->siglock); - sigorsets(&pending, ¤t->pending.signal, + sigorsets(set, ¤t->pending.signal, ¤t->signal->shared_pending.signal); spin_unlock_irq(¤t->sighand->siglock); /* Outside the lock because only this thread touches it. */ - sigandsets(&pending, ¤t->blocked, &pending); - - error = -EFAULT; - if (!copy_to_user(set, &pending, sigsetsize)) - error = 0; - -out: - return error; + sigandsets(set, ¤t->blocked, set); + return 0; } /** * sys_rt_sigpending - examine a pending signal that has been raised * while blocked - * @set: stores pending signals + * @uset: stores pending signals * @sigsetsize: size of sigset_t type or larger */ -SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, set, size_t, sigsetsize) +SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, uset, size_t, sigsetsize) { - return do_sigpending(set, sigsetsize); + sigset_t set; + int err = do_sigpending(&set, sigsetsize); + if (!err && copy_to_user(uset, &set, sigsetsize)) + err = -EFAULT; + return err; +} + +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE2(rt_sigpending, compat_sigset_t __user *, uset, + compat_size_t, sigsetsize) +{ +#ifdef __BIG_ENDIAN + sigset_t set; + int err = do_sigpending(&set, sigsetsize); + if (!err) { + compat_sigset_t set32; + sigset_to_compat(&set32, &set); + /* we can get here only if sigsetsize <= sizeof(set) */ + if (copy_to_user(uset, &set32, sigsetsize)) + err = -EFAULT; + } + return err; +#else + return sys_rt_sigpending((sigset_t __user *)uset, sigsetsize); +#endif } +#endif #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER @@ -2877,7 +2951,7 @@ do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) static int do_tkill(pid_t tgid, pid_t pid, int sig) { - struct siginfo info; + struct siginfo info = {}; info.si_signo = sig; info.si_errno = 0; @@ -2923,6 +2997,23 @@ SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig) return do_tkill(0, pid, sig); } +static int do_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t *info) +{ + /* Not even root can pretend to send signals from the kernel. + * Nor can they impersonate a kill()/tgkill(), which adds source info. + */ + if ((info->si_code >= 0 || info->si_code == SI_TKILL) && + (task_pid_vnr(current) != pid)) { + /* We used to allow any < 0 si_code */ + WARN_ON_ONCE(info->si_code < 0); + return -EPERM; + } + info->si_signo = sig; + + /* POSIX.1b doesn't mention process groups. */ + return kill_proc_info(sig, info, pid); +} + /** * sys_rt_sigqueueinfo - send signal information to a signal * @pid: the PID of the thread @@ -2933,25 +3024,26 @@ SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, siginfo_t __user *, uinfo) { siginfo_t info; - if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) return -EFAULT; + return do_rt_sigqueueinfo(pid, sig, &info); +} - /* Not even root can pretend to send signals from the kernel. - * Nor can they impersonate a kill()/tgkill(), which adds source info. - */ - if (info.si_code >= 0 || info.si_code == SI_TKILL) { - /* We used to allow any < 0 si_code */ - WARN_ON_ONCE(info.si_code < 0); - return -EPERM; - } - info.si_signo = sig; - - /* POSIX.1b doesn't mention process groups. */ - return kill_proc_info(sig, &info, pid); +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE3(rt_sigqueueinfo, + compat_pid_t, pid, + int, sig, + struct compat_siginfo __user *, uinfo) +{ + siginfo_t info; + int ret = copy_siginfo_from_user32(&info, uinfo); + if (unlikely(ret)) + return ret; + return do_rt_sigqueueinfo(pid, sig, &info); } +#endif -long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) +static int do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) { /* This is only valid for single tasks */ if (pid <= 0 || tgid <= 0) @@ -2960,7 +3052,8 @@ long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) /* Not even root can pretend to send signals from the kernel. * Nor can they impersonate a kill()/tgkill(), which adds source info. */ - if (info->si_code >= 0 || info->si_code == SI_TKILL) { + if (((info->si_code >= 0 || info->si_code == SI_TKILL)) && + (task_pid_vnr(current) != pid)) { /* We used to allow any < 0 si_code */ WARN_ON_ONCE(info->si_code < 0); return -EPERM; @@ -2981,6 +3074,21 @@ SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig, return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); } +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo, + compat_pid_t, tgid, + compat_pid_t, pid, + int, sig, + struct compat_siginfo __user *, uinfo) +{ + siginfo_t info; + + if (copy_siginfo_from_user32(&info, uinfo)) + return -EFAULT; + return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); +} +#endif + int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) { struct task_struct *t = current; @@ -3026,7 +3134,7 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) return 0; } -int +static int do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp) { stack_t oss; @@ -3091,12 +3199,10 @@ do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long s out: return error; } -#ifdef CONFIG_GENERIC_SIGALTSTACK SYSCALL_DEFINE2(sigaltstack,const stack_t __user *,uss, stack_t __user *,uoss) { return do_sigaltstack(uss, uoss, current_user_stack_pointer()); } -#endif int restore_altstack(const stack_t __user *uss) { @@ -3114,7 +3220,6 @@ int __save_altstack(stack_t __user *uss, unsigned long sp) } #ifdef CONFIG_COMPAT -#ifdef CONFIG_GENERIC_SIGALTSTACK COMPAT_SYSCALL_DEFINE2(sigaltstack, const compat_stack_t __user *, uss_ptr, compat_stack_t __user *, uoss_ptr) @@ -3164,7 +3269,6 @@ int __compat_save_altstack(compat_stack_t __user *uss, unsigned long sp) __put_user(t->sas_ss_size, &uss->ss_size); } #endif -#endif #ifdef __ARCH_WANT_SYS_SIGPENDING @@ -3174,7 +3278,7 @@ int __compat_save_altstack(compat_stack_t __user *uss, unsigned long sp) */ SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set) { - return do_sigpending(set, sizeof(*set)); + return sys_rt_sigpending((sigset_t __user *)set, sizeof(old_sigset_t)); } #endif @@ -3230,7 +3334,7 @@ SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, nset, } #endif /* __ARCH_WANT_SYS_SIGPROCMASK */ -#ifdef __ARCH_WANT_SYS_RT_SIGACTION +#ifndef CONFIG_ODD_RT_SIGACTION /** * sys_rt_sigaction - alter an action taken by a process * @sig: signal to be sent @@ -3264,7 +3368,132 @@ SYSCALL_DEFINE4(rt_sigaction, int, sig, out: return ret; } -#endif /* __ARCH_WANT_SYS_RT_SIGACTION */ +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE4(rt_sigaction, int, sig, + const struct compat_sigaction __user *, act, + struct compat_sigaction __user *, oact, + compat_size_t, sigsetsize) +{ + struct k_sigaction new_ka, old_ka; + compat_sigset_t mask; +#ifdef __ARCH_HAS_SA_RESTORER + compat_uptr_t restorer; +#endif + int ret; + + /* XXX: Don't preclude handling different sized sigset_t's. */ + if (sigsetsize != sizeof(compat_sigset_t)) + return -EINVAL; + + if (act) { + compat_uptr_t handler; + ret = get_user(handler, &act->sa_handler); + new_ka.sa.sa_handler = compat_ptr(handler); +#ifdef __ARCH_HAS_SA_RESTORER + ret |= get_user(restorer, &act->sa_restorer); + new_ka.sa.sa_restorer = compat_ptr(restorer); +#endif + ret |= copy_from_user(&mask, &act->sa_mask, sizeof(mask)); + ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags); + if (ret) + return -EFAULT; + sigset_from_compat(&new_ka.sa.sa_mask, &mask); + } + + ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); + if (!ret && oact) { + sigset_to_compat(&mask, &old_ka.sa.sa_mask); + ret = put_user(ptr_to_compat(old_ka.sa.sa_handler), + &oact->sa_handler); + ret |= copy_to_user(&oact->sa_mask, &mask, sizeof(mask)); + ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags); +#ifdef __ARCH_HAS_SA_RESTORER + ret |= put_user(ptr_to_compat(old_ka.sa.sa_restorer), + &oact->sa_restorer); +#endif + } + return ret; +} +#endif +#endif /* !CONFIG_ODD_RT_SIGACTION */ + +#ifdef CONFIG_OLD_SIGACTION +SYSCALL_DEFINE3(sigaction, int, sig, + const struct old_sigaction __user *, act, + struct old_sigaction __user *, oact) +{ + struct k_sigaction new_ka, old_ka; + int ret; + + if (act) { + old_sigset_t mask; + if (!access_ok(VERIFY_READ, act, sizeof(*act)) || + __get_user(new_ka.sa.sa_handler, &act->sa_handler) || + __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) || + __get_user(new_ka.sa.sa_flags, &act->sa_flags) || + __get_user(mask, &act->sa_mask)) + return -EFAULT; +#ifdef __ARCH_HAS_KA_RESTORER + new_ka.ka_restorer = NULL; +#endif + siginitset(&new_ka.sa.sa_mask, mask); + } + + ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); + + if (!ret && oact) { + if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || + __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || + __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) || + __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || + __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) + return -EFAULT; + } + + return ret; +} +#endif +#ifdef CONFIG_COMPAT_OLD_SIGACTION +COMPAT_SYSCALL_DEFINE3(sigaction, int, sig, + const struct compat_old_sigaction __user *, act, + struct compat_old_sigaction __user *, oact) +{ + struct k_sigaction new_ka, old_ka; + int ret; + compat_old_sigset_t mask; + compat_uptr_t handler, restorer; + + if (act) { + if (!access_ok(VERIFY_READ, act, sizeof(*act)) || + __get_user(handler, &act->sa_handler) || + __get_user(restorer, &act->sa_restorer) || + __get_user(new_ka.sa.sa_flags, &act->sa_flags) || + __get_user(mask, &act->sa_mask)) + return -EFAULT; + +#ifdef __ARCH_HAS_KA_RESTORER + new_ka.ka_restorer = NULL; +#endif + new_ka.sa.sa_handler = compat_ptr(handler); + new_ka.sa.sa_restorer = compat_ptr(restorer); + siginitset(&new_ka.sa.sa_mask, mask); + } + + ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); + + if (!ret && oact) { + if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || + __put_user(ptr_to_compat(old_ka.sa.sa_handler), + &oact->sa_handler) || + __put_user(ptr_to_compat(old_ka.sa.sa_restorer), + &oact->sa_restorer) || + __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || + __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) + return -EFAULT; + } + return ret; +} +#endif #ifdef __ARCH_WANT_SYS_SGETMASK @@ -3332,7 +3561,6 @@ int sigsuspend(sigset_t *set) return -ERESTARTNOHAND; } -#ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND /** * sys_rt_sigsuspend - replace the signal mask for a value with the * @unewset value until a signal is received @@ -3351,7 +3579,45 @@ SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize) return -EFAULT; return sigsuspend(&newset); } -#endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */ + +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE2(rt_sigsuspend, compat_sigset_t __user *, unewset, compat_size_t, sigsetsize) +{ +#ifdef __BIG_ENDIAN + sigset_t newset; + compat_sigset_t newset32; + + /* XXX: Don't preclude handling different sized sigset_t's. */ + if (sigsetsize != sizeof(sigset_t)) + return -EINVAL; + + if (copy_from_user(&newset32, unewset, sizeof(compat_sigset_t))) + return -EFAULT; + sigset_from_compat(&newset, &newset32); + return sigsuspend(&newset); +#else + /* on little-endian bitmaps don't care about granularity */ + return sys_rt_sigsuspend((sigset_t __user *)unewset, sigsetsize); +#endif +} +#endif + +#ifdef CONFIG_OLD_SIGSUSPEND +SYSCALL_DEFINE1(sigsuspend, old_sigset_t, mask) +{ + sigset_t blocked; + siginitset(&blocked, mask); + return sigsuspend(&blocked); +} +#endif +#ifdef CONFIG_OLD_SIGSUSPEND3 +SYSCALL_DEFINE3(sigsuspend, int, unused1, int, unused2, old_sigset_t, mask) +{ + sigset_t blocked; + siginitset(&blocked, mask); + return sigsuspend(&blocked); +} +#endif __attribute__((weak)) const char *arch_vma_name(struct vm_area_struct *vma) { diff --git a/kernel/smp.c b/kernel/smp.c index 69f38bd98b42..4dba0f7b72ad 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -16,22 +16,12 @@ #include "smpboot.h" #ifdef CONFIG_USE_GENERIC_SMP_HELPERS -static struct { - struct list_head queue; - raw_spinlock_t lock; -} call_function __cacheline_aligned_in_smp = - { - .queue = LIST_HEAD_INIT(call_function.queue), - .lock = __RAW_SPIN_LOCK_UNLOCKED(call_function.lock), - }; - enum { CSD_FLAG_LOCK = 0x01, }; struct call_function_data { - struct call_single_data csd; - atomic_t refs; + struct call_single_data __percpu *csd; cpumask_var_t cpumask; cpumask_var_t cpumask_ipi; }; @@ -60,6 +50,11 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu) if (!zalloc_cpumask_var_node(&cfd->cpumask_ipi, GFP_KERNEL, cpu_to_node(cpu))) return notifier_from_errno(-ENOMEM); + cfd->csd = alloc_percpu(struct call_single_data); + if (!cfd->csd) { + free_cpumask_var(cfd->cpumask); + return notifier_from_errno(-ENOMEM); + } break; #ifdef CONFIG_HOTPLUG_CPU @@ -70,6 +65,7 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu) case CPU_DEAD_FROZEN: free_cpumask_var(cfd->cpumask); free_cpumask_var(cfd->cpumask_ipi); + free_percpu(cfd->csd); break; #endif }; @@ -104,16 +100,16 @@ void __init call_function_init(void) * previous function call. For multi-cpu calls its even more interesting * as we'll have to ensure no other cpu is observing our csd. */ -static void csd_lock_wait(struct call_single_data *data) +static void csd_lock_wait(struct call_single_data *csd) { - while (data->flags & CSD_FLAG_LOCK) + while (csd->flags & CSD_FLAG_LOCK) cpu_relax(); } -static void csd_lock(struct call_single_data *data) +static void csd_lock(struct call_single_data *csd) { - csd_lock_wait(data); - data->flags = CSD_FLAG_LOCK; + csd_lock_wait(csd); + csd->flags |= CSD_FLAG_LOCK; /* * prevent CPU from reordering the above assignment @@ -123,16 +119,16 @@ static void csd_lock(struct call_single_data *data) smp_mb(); } -static void csd_unlock(struct call_single_data *data) +static void csd_unlock(struct call_single_data *csd) { - WARN_ON(!(data->flags & CSD_FLAG_LOCK)); + WARN_ON(!(csd->flags & CSD_FLAG_LOCK)); /* * ensure we're all done before releasing data: */ smp_mb(); - data->flags &= ~CSD_FLAG_LOCK; + csd->flags &= ~CSD_FLAG_LOCK; } /* @@ -141,7 +137,7 @@ static void csd_unlock(struct call_single_data *data) * ->func, ->info, and ->flags set. */ static -void generic_exec_single(int cpu, struct call_single_data *data, int wait) +void generic_exec_single(int cpu, struct call_single_data *csd, int wait) { struct call_single_queue *dst = &per_cpu(call_single_queue, cpu); unsigned long flags; @@ -149,7 +145,7 @@ void generic_exec_single(int cpu, struct call_single_data *data, int wait) raw_spin_lock_irqsave(&dst->lock, flags); ipi = list_empty(&dst->list); - list_add_tail(&data->list, &dst->list); + list_add_tail(&csd->list, &dst->list); raw_spin_unlock_irqrestore(&dst->lock, flags); /* @@ -167,86 +163,7 @@ void generic_exec_single(int cpu, struct call_single_data *data, int wait) arch_send_call_function_single_ipi(cpu); if (wait) - csd_lock_wait(data); -} - -/* - * Invoked by arch to handle an IPI for call function. Must be called with - * interrupts disabled. - */ -void generic_smp_call_function_interrupt(void) -{ - struct call_function_data *data; - int cpu = smp_processor_id(); - - /* - * Shouldn't receive this interrupt on a cpu that is not yet online. - */ - WARN_ON_ONCE(!cpu_online(cpu)); - - /* - * Ensure entry is visible on call_function_queue after we have - * entered the IPI. See comment in smp_call_function_many. - * If we don't have this, then we may miss an entry on the list - * and never get another IPI to process it. - */ - smp_mb(); - - /* - * It's ok to use list_for_each_rcu() here even though we may - * delete 'pos', since list_del_rcu() doesn't clear ->next - */ - list_for_each_entry_rcu(data, &call_function.queue, csd.list) { - int refs; - smp_call_func_t func; - - /* - * Since we walk the list without any locks, we might - * see an entry that was completed, removed from the - * list and is in the process of being reused. - * - * We must check that the cpu is in the cpumask before - * checking the refs, and both must be set before - * executing the callback on this cpu. - */ - - if (!cpumask_test_cpu(cpu, data->cpumask)) - continue; - - smp_rmb(); - - if (atomic_read(&data->refs) == 0) - continue; - - func = data->csd.func; /* save for later warn */ - func(data->csd.info); - - /* - * If the cpu mask is not still set then func enabled - * interrupts (BUG), and this cpu took another smp call - * function interrupt and executed func(info) twice - * on this cpu. That nested execution decremented refs. - */ - if (!cpumask_test_and_clear_cpu(cpu, data->cpumask)) { - WARN(1, "%pf enabled interrupts and double executed\n", func); - continue; - } - - refs = atomic_dec_return(&data->refs); - WARN_ON(refs < 0); - - if (refs) - continue; - - WARN_ON(!cpumask_empty(data->cpumask)); - - raw_spin_lock(&call_function.lock); - list_del_rcu(&data->csd.list); - raw_spin_unlock(&call_function.lock); - - csd_unlock(&data->csd); - } - + csd_lock_wait(csd); } /* @@ -256,7 +173,6 @@ void generic_smp_call_function_interrupt(void) void generic_smp_call_function_single_interrupt(void) { struct call_single_queue *q = &__get_cpu_var(call_single_queue); - unsigned int data_flags; LIST_HEAD(list); /* @@ -269,25 +185,26 @@ void generic_smp_call_function_single_interrupt(void) raw_spin_unlock(&q->lock); while (!list_empty(&list)) { - struct call_single_data *data; + struct call_single_data *csd; + unsigned int csd_flags; - data = list_entry(list.next, struct call_single_data, list); - list_del(&data->list); + csd = list_entry(list.next, struct call_single_data, list); + list_del(&csd->list); /* - * 'data' can be invalid after this call if flags == 0 + * 'csd' can be invalid after this call if flags == 0 * (when called through generic_exec_single()), * so save them away before making the call: */ - data_flags = data->flags; + csd_flags = csd->flags; - data->func(data->info); + csd->func(csd->info); /* * Unlocked CSDs are valid through generic_exec_single(): */ - if (data_flags & CSD_FLAG_LOCK) - csd_unlock(data); + if (csd_flags & CSD_FLAG_LOCK) + csd_unlock(csd); } } @@ -332,16 +249,16 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info, local_irq_restore(flags); } else { if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) { - struct call_single_data *data = &d; + struct call_single_data *csd = &d; if (!wait) - data = &__get_cpu_var(csd_data); + csd = &__get_cpu_var(csd_data); - csd_lock(data); + csd_lock(csd); - data->func = func; - data->info = info; - generic_exec_single(cpu, data, wait); + csd->func = func; + csd->info = info; + generic_exec_single(cpu, csd, wait); } else { err = -ENXIO; /* CPU not online */ } @@ -408,7 +325,7 @@ EXPORT_SYMBOL_GPL(smp_call_function_any); * pre-allocated data structure. Useful for embedding @data inside * other structures, for instance. */ -void __smp_call_function_single(int cpu, struct call_single_data *data, +void __smp_call_function_single(int cpu, struct call_single_data *csd, int wait) { unsigned int this_cpu; @@ -426,11 +343,11 @@ void __smp_call_function_single(int cpu, struct call_single_data *data, if (cpu == this_cpu) { local_irq_save(flags); - data->func(data->info); + csd->func(csd->info); local_irq_restore(flags); } else { - csd_lock(data); - generic_exec_single(cpu, data, wait); + csd_lock(csd); + generic_exec_single(cpu, csd, wait); } put_cpu(); } @@ -452,9 +369,8 @@ void __smp_call_function_single(int cpu, struct call_single_data *data, void smp_call_function_many(const struct cpumask *mask, smp_call_func_t func, void *info, bool wait) { - struct call_function_data *data; - unsigned long flags; - int refs, cpu, next_cpu, this_cpu = smp_processor_id(); + struct call_function_data *cfd; + int cpu, next_cpu, this_cpu = smp_processor_id(); /* * Can deadlock when called with interrupts disabled. @@ -485,86 +401,48 @@ void smp_call_function_many(const struct cpumask *mask, return; } - data = &__get_cpu_var(cfd_data); - csd_lock(&data->csd); - - /* This BUG_ON verifies our reuse assertions and can be removed */ - BUG_ON(atomic_read(&data->refs) || !cpumask_empty(data->cpumask)); - - /* - * The global call function queue list add and delete are protected - * by a lock, but the list is traversed without any lock, relying - * on the rcu list add and delete to allow safe concurrent traversal. - * We reuse the call function data without waiting for any grace - * period after some other cpu removes it from the global queue. - * This means a cpu might find our data block as it is being - * filled out. - * - * We hold off the interrupt handler on the other cpu by - * ordering our writes to the cpu mask vs our setting of the - * refs counter. We assert only the cpu owning the data block - * will set a bit in cpumask, and each bit will only be cleared - * by the subject cpu. Each cpu must first find its bit is - * set and then check that refs is set indicating the element is - * ready to be processed, otherwise it must skip the entry. - * - * On the previous iteration refs was set to 0 by another cpu. - * To avoid the use of transitivity, set the counter to 0 here - * so the wmb will pair with the rmb in the interrupt handler. - */ - atomic_set(&data->refs, 0); /* convert 3rd to 1st party write */ - - data->csd.func = func; - data->csd.info = info; - - /* Ensure 0 refs is visible before mask. Also orders func and info */ - smp_wmb(); + cfd = &__get_cpu_var(cfd_data); - /* We rely on the "and" being processed before the store */ - cpumask_and(data->cpumask, mask, cpu_online_mask); - cpumask_clear_cpu(this_cpu, data->cpumask); - refs = cpumask_weight(data->cpumask); + cpumask_and(cfd->cpumask, mask, cpu_online_mask); + cpumask_clear_cpu(this_cpu, cfd->cpumask); /* Some callers race with other cpus changing the passed mask */ - if (unlikely(!refs)) { - csd_unlock(&data->csd); + if (unlikely(!cpumask_weight(cfd->cpumask))) return; - } /* - * After we put an entry into the list, data->cpumask - * may be cleared again when another CPU sends another IPI for - * a SMP function call, so data->cpumask will be zero. - */ - cpumask_copy(data->cpumask_ipi, data->cpumask); - raw_spin_lock_irqsave(&call_function.lock, flags); - /* - * Place entry at the _HEAD_ of the list, so that any cpu still - * observing the entry in generic_smp_call_function_interrupt() - * will not miss any other list entries: - */ - list_add_rcu(&data->csd.list, &call_function.queue); - /* - * We rely on the wmb() in list_add_rcu to complete our writes - * to the cpumask before this write to refs, which indicates - * data is on the list and is ready to be processed. + * After we put an entry into the list, cfd->cpumask may be cleared + * again when another CPU sends another IPI for a SMP function call, so + * cfd->cpumask will be zero. */ - atomic_set(&data->refs, refs); - raw_spin_unlock_irqrestore(&call_function.lock, flags); + cpumask_copy(cfd->cpumask_ipi, cfd->cpumask); - /* - * Make the list addition visible before sending the ipi. - * (IPIs must obey or appear to obey normal Linux cache - * coherency rules -- see comment in generic_exec_single). - */ - smp_mb(); + for_each_cpu(cpu, cfd->cpumask) { + struct call_single_data *csd = per_cpu_ptr(cfd->csd, cpu); + struct call_single_queue *dst = + &per_cpu(call_single_queue, cpu); + unsigned long flags; + + csd_lock(csd); + csd->func = func; + csd->info = info; + + raw_spin_lock_irqsave(&dst->lock, flags); + list_add_tail(&csd->list, &dst->list); + raw_spin_unlock_irqrestore(&dst->lock, flags); + } /* Send a message to all CPUs in the map */ - arch_send_call_function_ipi_mask(data->cpumask_ipi); + arch_send_call_function_ipi_mask(cfd->cpumask_ipi); - /* Optionally wait for the CPUs to complete */ - if (wait) - csd_lock_wait(&data->csd); + if (wait) { + for_each_cpu(cpu, cfd->cpumask) { + struct call_single_data *csd; + + csd = per_cpu_ptr(cfd->csd, cpu); + csd_lock_wait(csd); + } + } } EXPORT_SYMBOL(smp_call_function_many); diff --git a/kernel/smpboot.c b/kernel/smpboot.c index d6c5fc054242..02fc5c933673 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -183,9 +183,20 @@ __smpboot_create_thread(struct smp_hotplug_thread *ht, unsigned int cpu) kfree(td); return PTR_ERR(tsk); } - get_task_struct(tsk); *per_cpu_ptr(ht->store, cpu) = tsk; + if (ht->create) { + /* + * Make sure that the task has actually scheduled out + * into park position, before calling the create + * callback. At least the migration thread callback + * requires that the task is off the runqueue. + */ + if (!wait_task_inactive(tsk, TASK_PARKED)) + WARN_ON(1); + else + ht->create(cpu); + } return 0; } @@ -208,6 +219,8 @@ static void smpboot_unpark_thread(struct smp_hotplug_thread *ht, unsigned int cp { struct task_struct *tsk = *per_cpu_ptr(ht->store, cpu); + if (ht->pre_unpark) + ht->pre_unpark(cpu); kthread_unpark(tsk); } @@ -225,7 +238,7 @@ static void smpboot_park_thread(struct smp_hotplug_thread *ht, unsigned int cpu) { struct task_struct *tsk = *per_cpu_ptr(ht->store, cpu); - if (tsk) + if (tsk && !ht->selfparking) kthread_park(tsk); } diff --git a/kernel/softirq.c b/kernel/softirq.c index ed567babe789..b5197dcb0dad 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -195,21 +195,21 @@ void local_bh_enable_ip(unsigned long ip) EXPORT_SYMBOL(local_bh_enable_ip); /* - * We restart softirq processing MAX_SOFTIRQ_RESTART times, - * and we fall back to softirqd after that. + * We restart softirq processing for at most 2 ms, + * and if need_resched() is not set. * - * This number has been established via experimentation. + * These limits have been established via experimentation. * The two things to balance is latency against fairness - * we want to handle softirqs as soon as possible, but they * should not be able to lock up the box. */ -#define MAX_SOFTIRQ_RESTART 10 +#define MAX_SOFTIRQ_TIME msecs_to_jiffies(2) asmlinkage void __do_softirq(void) { struct softirq_action *h; __u32 pending; - int max_restart = MAX_SOFTIRQ_RESTART; + unsigned long end = jiffies + MAX_SOFTIRQ_TIME; int cpu; unsigned long old_flags = current->flags; @@ -221,7 +221,7 @@ asmlinkage void __do_softirq(void) current->flags &= ~PF_MEMALLOC; pending = local_softirq_pending(); - vtime_account_irq_enter(current); + account_irq_enter_time(current); __local_bh_disable((unsigned long)__builtin_return_address(0), SOFTIRQ_OFFSET); @@ -264,15 +264,16 @@ restart: local_irq_disable(); pending = local_softirq_pending(); - if (pending && --max_restart) - goto restart; + if (pending) { + if (time_before(jiffies, end) && !need_resched()) + goto restart; - if (pending) wakeup_softirqd(); + } lockdep_softirq_exit(); - vtime_account_irq_exit(current); + account_irq_exit_time(current); __local_bh_enable(SOFTIRQ_OFFSET); tsk_restore_flags(current, old_flags, PF_MEMALLOC); } @@ -322,18 +323,23 @@ void irq_enter(void) static inline void invoke_softirq(void) { - if (!force_irqthreads) { -#ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED + if (!force_irqthreads) __do_softirq(); -#else - do_softirq(); -#endif - } else { - __local_bh_disable((unsigned long)__builtin_return_address(0), - SOFTIRQ_OFFSET); + else wakeup_softirqd(); - __local_bh_enable(SOFTIRQ_OFFSET); +} + +static inline void tick_irq_exit(void) +{ +#ifdef CONFIG_NO_HZ_COMMON + int cpu = smp_processor_id(); + + /* Make sure that timer wheel updates are propagated */ + if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu)) { + if (!in_interrupt()) + tick_nohz_irq_exit(); } +#endif } /* @@ -341,19 +347,20 @@ static inline void invoke_softirq(void) */ void irq_exit(void) { - vtime_account_irq_exit(current); +#ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED + local_irq_disable(); +#else + WARN_ON_ONCE(!irqs_disabled()); +#endif + + account_irq_exit_time(current); trace_hardirq_exit(); - sub_preempt_count(IRQ_EXIT_OFFSET); + sub_preempt_count(HARDIRQ_OFFSET); if (!in_interrupt() && local_softirq_pending()) invoke_softirq(); -#ifdef CONFIG_NO_HZ - /* Make sure that timer wheel updates are propagated */ - if (idle_cpu(smp_processor_id()) && !in_interrupt() && !need_resched()) - tick_nohz_irq_exit(); -#endif + tick_irq_exit(); rcu_irq_exit(); - sched_preempt_enable_no_resched(); } /* @@ -622,8 +629,7 @@ static void remote_softirq_receive(void *data) unsigned long flags; int softirq; - softirq = cp->priv; - + softirq = *(int *)cp->info; local_irq_save(flags); __local_trigger(cp, softirq); local_irq_restore(flags); @@ -633,9 +639,8 @@ static int __try_remote_softirq(struct call_single_data *cp, int cpu, int softir { if (cpu_online(cpu)) { cp->func = remote_softirq_receive; - cp->info = cp; + cp->info = &softirq; cp->flags = 0; - cp->priv = softirq; __smp_call_function_single(cpu, cp, 0); return 0; diff --git a/kernel/srcu.c b/kernel/srcu.c index 2b859828cdc3..01d5ccb8bfe3 100644 --- a/kernel/srcu.c +++ b/kernel/srcu.c @@ -282,12 +282,8 @@ static int srcu_readers_active(struct srcu_struct *sp) */ void cleanup_srcu_struct(struct srcu_struct *sp) { - int sum; - - sum = srcu_readers_active(sp); - WARN_ON(sum); /* Leakage unless caller handles error. */ - if (sum != 0) - return; + if (WARN_ON(srcu_readers_active(sp))) + return; /* Leakage unless caller handles error. */ free_percpu(sp->per_cpu_ref); sp->per_cpu_ref = NULL; } @@ -302,9 +298,8 @@ int __srcu_read_lock(struct srcu_struct *sp) { int idx; + idx = ACCESS_ONCE(sp->completed) & 0x1; preempt_disable(); - idx = rcu_dereference_index_check(sp->completed, - rcu_read_lock_sched_held()) & 0x1; ACCESS_ONCE(this_cpu_ptr(sp->per_cpu_ref)->c[idx]) += 1; smp_mb(); /* B */ /* Avoid leaking the critical section. */ ACCESS_ONCE(this_cpu_ptr(sp->per_cpu_ref)->seq[idx]) += 1; @@ -321,10 +316,8 @@ EXPORT_SYMBOL_GPL(__srcu_read_lock); */ void __srcu_read_unlock(struct srcu_struct *sp, int idx) { - preempt_disable(); smp_mb(); /* C */ /* Avoid leaking the critical section. */ - ACCESS_ONCE(this_cpu_ptr(sp->per_cpu_ref)->c[idx]) -= 1; - preempt_enable(); + this_cpu_dec(sp->per_cpu_ref->c[idx]); } EXPORT_SYMBOL_GPL(__srcu_read_unlock); @@ -423,6 +416,7 @@ static void __synchronize_srcu(struct srcu_struct *sp, int trycount) !lock_is_held(&rcu_sched_lock_map), "Illegal synchronize_srcu() in same-type SRCU (or RCU) read-side critical section"); + might_sleep(); init_completion(&rcu.completion); head->next = NULL; @@ -455,10 +449,12 @@ static void __synchronize_srcu(struct srcu_struct *sp, int trycount) * synchronize_srcu - wait for prior SRCU read-side critical-section completion * @sp: srcu_struct with which to synchronize. * - * Flip the completed counter, and wait for the old count to drain to zero. - * As with classic RCU, the updater must use some separate means of - * synchronizing concurrent updates. Can block; must be called from - * process context. + * Wait for the count to drain to zero of both indexes. To avoid the + * possible starvation of synchronize_srcu(), it waits for the count of + * the index=((->completed & 1) ^ 1) to drain to zero at first, + * and then flip the completed and wait for the count of the other index. + * + * Can block; must be called from process context. * * Note that it is illegal to call synchronize_srcu() from the corresponding * SRCU read-side critical section; doing so will result in deadlock. @@ -480,12 +476,11 @@ EXPORT_SYMBOL_GPL(synchronize_srcu); * Wait for an SRCU grace period to elapse, but be more aggressive about * spinning rather than blocking when waiting. * - * Note that it is illegal to call this function while holding any lock - * that is acquired by a CPU-hotplug notifier. It is also illegal to call - * synchronize_srcu_expedited() from the corresponding SRCU read-side - * critical section; doing so will result in deadlock. However, it is - * perfectly legal to call synchronize_srcu_expedited() on one srcu_struct - * from some other srcu_struct's read-side critical section, as long as + * Note that it is also illegal to call synchronize_srcu_expedited() + * from the corresponding SRCU read-side critical section; + * doing so will result in deadlock. However, it is perfectly legal + * to call synchronize_srcu_expedited() on one srcu_struct from some + * other srcu_struct's read-side critical section, as long as * the resulting graph of srcu_structs is acyclic. */ void synchronize_srcu_expedited(struct srcu_struct *sp) diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 2f194e965715..c09f2955ae30 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -18,7 +18,7 @@ #include <linux/stop_machine.h> #include <linux/interrupt.h> #include <linux/kallsyms.h> - +#include <linux/smpboot.h> #include <linux/atomic.h> /* @@ -37,10 +37,10 @@ struct cpu_stopper { spinlock_t lock; bool enabled; /* is this stopper enabled? */ struct list_head works; /* list of pending works */ - struct task_struct *thread; /* stopper thread */ }; static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper); +static DEFINE_PER_CPU(struct task_struct *, cpu_stopper_task); static bool stop_machine_initialized = false; static void cpu_stop_init_done(struct cpu_stop_done *done, unsigned int nr_todo) @@ -62,16 +62,18 @@ static void cpu_stop_signal_done(struct cpu_stop_done *done, bool executed) } /* queue @work to @stopper. if offline, @work is completed immediately */ -static void cpu_stop_queue_work(struct cpu_stopper *stopper, - struct cpu_stop_work *work) +static void cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work) { + struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); + struct task_struct *p = per_cpu(cpu_stopper_task, cpu); + unsigned long flags; spin_lock_irqsave(&stopper->lock, flags); if (stopper->enabled) { list_add_tail(&work->list, &stopper->works); - wake_up_process(stopper->thread); + wake_up_process(p); } else cpu_stop_signal_done(work->done, false); @@ -108,7 +110,7 @@ int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done }; cpu_stop_init_done(&done, 1); - cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), &work); + cpu_stop_queue_work(cpu, &work); wait_for_completion(&done.completion); return done.executed ? done.ret : -ENOENT; } @@ -130,7 +132,7 @@ void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, struct cpu_stop_work *work_buf) { *work_buf = (struct cpu_stop_work){ .fn = fn, .arg = arg, }; - cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), work_buf); + cpu_stop_queue_work(cpu, work_buf); } /* static data for stop_cpus */ @@ -159,8 +161,7 @@ static void queue_stop_cpus_work(const struct cpumask *cpumask, */ preempt_disable(); for_each_cpu(cpu, cpumask) - cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), - &per_cpu(stop_cpus_work, cpu)); + cpu_stop_queue_work(cpu, &per_cpu(stop_cpus_work, cpu)); preempt_enable(); } @@ -244,20 +245,25 @@ int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg) return ret; } -static int cpu_stopper_thread(void *data) +static int cpu_stop_should_run(unsigned int cpu) +{ + struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); + unsigned long flags; + int run; + + spin_lock_irqsave(&stopper->lock, flags); + run = !list_empty(&stopper->works); + spin_unlock_irqrestore(&stopper->lock, flags); + return run; +} + +static void cpu_stopper_thread(unsigned int cpu) { - struct cpu_stopper *stopper = data; + struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); struct cpu_stop_work *work; int ret; repeat: - set_current_state(TASK_INTERRUPTIBLE); /* mb paired w/ kthread_stop */ - - if (kthread_should_stop()) { - __set_current_state(TASK_RUNNING); - return 0; - } - work = NULL; spin_lock_irq(&stopper->lock); if (!list_empty(&stopper->works)) { @@ -273,8 +279,6 @@ repeat: struct cpu_stop_done *done = work->done; char ksym_buf[KSYM_NAME_LEN] __maybe_unused; - __set_current_state(TASK_RUNNING); - /* cpu stop callbacks are not allowed to sleep */ preempt_disable(); @@ -290,88 +294,55 @@ repeat: ksym_buf), arg); cpu_stop_signal_done(done, true); - } else - schedule(); - - goto repeat; + goto repeat; + } } extern void sched_set_stop_task(int cpu, struct task_struct *stop); -/* manage stopper for a cpu, mostly lifted from sched migration thread mgmt */ -static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb, - unsigned long action, void *hcpu) +static void cpu_stop_create(unsigned int cpu) +{ + sched_set_stop_task(cpu, per_cpu(cpu_stopper_task, cpu)); +} + +static void cpu_stop_park(unsigned int cpu) { - unsigned int cpu = (unsigned long)hcpu; struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); - struct task_struct *p; - - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_UP_PREPARE: - BUG_ON(stopper->thread || stopper->enabled || - !list_empty(&stopper->works)); - p = kthread_create_on_node(cpu_stopper_thread, - stopper, - cpu_to_node(cpu), - "migration/%d", cpu); - if (IS_ERR(p)) - return notifier_from_errno(PTR_ERR(p)); - get_task_struct(p); - kthread_bind(p, cpu); - sched_set_stop_task(cpu, p); - stopper->thread = p; - break; - - case CPU_ONLINE: - /* strictly unnecessary, as first user will wake it */ - wake_up_process(stopper->thread); - /* mark enabled */ - spin_lock_irq(&stopper->lock); - stopper->enabled = true; - spin_unlock_irq(&stopper->lock); - break; - -#ifdef CONFIG_HOTPLUG_CPU - case CPU_UP_CANCELED: - case CPU_POST_DEAD: - { - struct cpu_stop_work *work; - - sched_set_stop_task(cpu, NULL); - /* kill the stopper */ - kthread_stop(stopper->thread); - /* drain remaining works */ - spin_lock_irq(&stopper->lock); - list_for_each_entry(work, &stopper->works, list) - cpu_stop_signal_done(work->done, false); - stopper->enabled = false; - spin_unlock_irq(&stopper->lock); - /* release the stopper */ - put_task_struct(stopper->thread); - stopper->thread = NULL; - break; - } -#endif - } + struct cpu_stop_work *work; + unsigned long flags; - return NOTIFY_OK; + /* drain remaining works */ + spin_lock_irqsave(&stopper->lock, flags); + list_for_each_entry(work, &stopper->works, list) + cpu_stop_signal_done(work->done, false); + stopper->enabled = false; + spin_unlock_irqrestore(&stopper->lock, flags); } -/* - * Give it a higher priority so that cpu stopper is available to other - * cpu notifiers. It currently shares the same priority as sched - * migration_notifier. - */ -static struct notifier_block __cpuinitdata cpu_stop_cpu_notifier = { - .notifier_call = cpu_stop_cpu_callback, - .priority = 10, +static void cpu_stop_unpark(unsigned int cpu) +{ + struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); + + spin_lock_irq(&stopper->lock); + stopper->enabled = true; + spin_unlock_irq(&stopper->lock); +} + +static struct smp_hotplug_thread cpu_stop_threads = { + .store = &cpu_stopper_task, + .thread_should_run = cpu_stop_should_run, + .thread_fn = cpu_stopper_thread, + .thread_comm = "migration/%u", + .create = cpu_stop_create, + .setup = cpu_stop_unpark, + .park = cpu_stop_park, + .pre_unpark = cpu_stop_unpark, + .selfparking = true, }; static int __init cpu_stop_init(void) { - void *bcpu = (void *)(long)smp_processor_id(); unsigned int cpu; - int err; for_each_possible_cpu(cpu) { struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); @@ -380,15 +351,8 @@ static int __init cpu_stop_init(void) INIT_LIST_HEAD(&stopper->works); } - /* start one for the boot cpu */ - err = cpu_stop_cpu_callback(&cpu_stop_cpu_notifier, CPU_UP_PREPARE, - bcpu); - BUG_ON(err != NOTIFY_OK); - cpu_stop_cpu_callback(&cpu_stop_cpu_notifier, CPU_ONLINE, bcpu); - register_cpu_notifier(&cpu_stop_cpu_notifier); - + BUG_ON(smpboot_register_percpu_thread(&cpu_stop_threads)); stop_machine_initialized = true; - return 0; } early_initcall(cpu_stop_init); diff --git a/kernel/sys.c b/kernel/sys.c index 265b37690421..b95d3c72ba21 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -47,6 +47,12 @@ #include <linux/syscalls.h> #include <linux/kprobes.h> #include <linux/user_namespace.h> +#include <linux/binfmts.h> + +#include <linux/sched.h> +#include <linux/rcupdate.h> +#include <linux/uidgid.h> +#include <linux/cred.h> #include <linux/kmsg_dump.h> /* Move somewhere else to avoid recompiling? */ @@ -323,7 +329,6 @@ void kernel_restart_prepare(char *cmd) system_state = SYSTEM_RESTART; usermodehelper_disable(); device_shutdown(); - syscore_shutdown(); } /** @@ -369,6 +374,7 @@ void kernel_restart(char *cmd) { kernel_restart_prepare(cmd); disable_nonboot_cpus(); + syscore_shutdown(); if (!cmd) printk(KERN_EMERG "Restarting system.\n"); else @@ -394,6 +400,7 @@ static void kernel_shutdown_prepare(enum system_states state) void kernel_halt(void) { kernel_shutdown_prepare(SYSTEM_HALT); + disable_nonboot_cpus(); syscore_shutdown(); printk(KERN_EMERG "System halted.\n"); kmsg_dump(KMSG_DUMP_HALT); @@ -433,11 +440,12 @@ static DEFINE_MUTEX(reboot_mutex); SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, void __user *, arg) { + struct pid_namespace *pid_ns = task_active_pid_ns(current); char buffer[256]; int ret = 0; /* We only trust the superuser with rebooting the system. */ - if (!capable(CAP_SYS_BOOT)) + if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT)) return -EPERM; /* For safety, we require "magic" arguments. */ @@ -453,7 +461,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, * pid_namespace, the command is handled by reboot_pid_ns() which will * call do_exit(). */ - ret = reboot_pid_ns(task_active_pid_ns(current), cmd); + ret = reboot_pid_ns(pid_ns, cmd); if (ret) return ret; @@ -1041,6 +1049,67 @@ change_okay: return old_fsgid; } +/** + * sys_getpid - return the thread group id of the current process + * + * Note, despite the name, this returns the tgid not the pid. The tgid and + * the pid are identical unless CLONE_THREAD was specified on clone() in + * which case the tgid is the same in all threads of the same group. + * + * This is SMP safe as current->tgid does not change. + */ +SYSCALL_DEFINE0(getpid) +{ + return task_tgid_vnr(current); +} + +/* Thread ID - the internal kernel "pid" */ +SYSCALL_DEFINE0(gettid) +{ + return task_pid_vnr(current); +} + +/* + * Accessing ->real_parent is not SMP-safe, it could + * change from under us. However, we can use a stale + * value of ->real_parent under rcu_read_lock(), see + * release_task()->call_rcu(delayed_put_task_struct). + */ +SYSCALL_DEFINE0(getppid) +{ + int pid; + + rcu_read_lock(); + pid = task_tgid_vnr(rcu_dereference(current->real_parent)); + rcu_read_unlock(); + + return pid; +} + +SYSCALL_DEFINE0(getuid) +{ + /* Only we change this so SMP safe */ + return from_kuid_munged(current_user_ns(), current_uid()); +} + +SYSCALL_DEFINE0(geteuid) +{ + /* Only we change this so SMP safe */ + return from_kuid_munged(current_user_ns(), current_euid()); +} + +SYSCALL_DEFINE0(getgid) +{ + /* Only we change this so SMP safe */ + return from_kgid_munged(current_user_ns(), current_gid()); +} + +SYSCALL_DEFINE0(getegid) +{ + /* Only we change this so SMP safe */ + return from_kgid_munged(current_user_ns(), current_egid()); +} + void do_sys_times(struct tms *tms) { cputime_t tgutime, tgstime, cutime, cstime; @@ -1782,24 +1851,37 @@ SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) return getrusage(current, who, ru); } +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) +{ + struct rusage r; + + if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && + who != RUSAGE_THREAD) + return -EINVAL; + + k_getrusage(current, who, &r); + return put_compat_rusage(&r, ru); +} +#endif + SYSCALL_DEFINE1(umask, int, mask) { mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); return mask; } -#ifdef CONFIG_CHECKPOINT_RESTORE static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) { struct fd exe; - struct dentry *dentry; + struct inode *inode; int err; exe = fdget(fd); if (!exe.file) return -EBADF; - dentry = exe.file->f_path.dentry; + inode = file_inode(exe.file); /* * Because the original mm->exe_file points to executable file, make @@ -1807,11 +1889,11 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) * overall picture. */ err = -EACCES; - if (!S_ISREG(dentry->d_inode->i_mode) || + if (!S_ISREG(inode->i_mode) || exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC) goto exit; - err = inode_permission(dentry->d_inode, MAY_EXEC); + err = inode_permission(inode, MAY_EXEC); if (err) goto exit; @@ -1982,17 +2064,12 @@ out: return error; } +#ifdef CONFIG_CHECKPOINT_RESTORE static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) { return put_user(me->clear_child_tid, tid_addr); } - -#else /* CONFIG_CHECKPOINT_RESTORE */ -static int prctl_set_mm(int opt, unsigned long addr, - unsigned long arg4, unsigned long arg5) -{ - return -EINVAL; -} +#else static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) { return -EINVAL; @@ -2012,160 +2089,159 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, error = 0; switch (option) { - case PR_SET_PDEATHSIG: - if (!valid_signal(arg2)) { - error = -EINVAL; - break; - } - me->pdeath_signal = arg2; - break; - case PR_GET_PDEATHSIG: - error = put_user(me->pdeath_signal, (int __user *)arg2); - break; - case PR_GET_DUMPABLE: - error = get_dumpable(me->mm); + case PR_SET_PDEATHSIG: + if (!valid_signal(arg2)) { + error = -EINVAL; break; - case PR_SET_DUMPABLE: - if (arg2 < 0 || arg2 > 1) { - error = -EINVAL; - break; - } - set_dumpable(me->mm, arg2); + } + me->pdeath_signal = arg2; + break; + case PR_GET_PDEATHSIG: + error = put_user(me->pdeath_signal, (int __user *)arg2); + break; + case PR_GET_DUMPABLE: + error = get_dumpable(me->mm); + break; + case PR_SET_DUMPABLE: + if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { + error = -EINVAL; break; + } + set_dumpable(me->mm, arg2); + break; - case PR_SET_UNALIGN: - error = SET_UNALIGN_CTL(me, arg2); - break; - case PR_GET_UNALIGN: - error = GET_UNALIGN_CTL(me, arg2); - break; - case PR_SET_FPEMU: - error = SET_FPEMU_CTL(me, arg2); - break; - case PR_GET_FPEMU: - error = GET_FPEMU_CTL(me, arg2); - break; - case PR_SET_FPEXC: - error = SET_FPEXC_CTL(me, arg2); - break; - case PR_GET_FPEXC: - error = GET_FPEXC_CTL(me, arg2); - break; - case PR_GET_TIMING: - error = PR_TIMING_STATISTICAL; - break; - case PR_SET_TIMING: - if (arg2 != PR_TIMING_STATISTICAL) - error = -EINVAL; - break; - case PR_SET_NAME: - comm[sizeof(me->comm)-1] = 0; - if (strncpy_from_user(comm, (char __user *)arg2, - sizeof(me->comm) - 1) < 0) - return -EFAULT; - set_task_comm(me, comm); - proc_comm_connector(me); - break; - case PR_GET_NAME: - get_task_comm(comm, me); - if (copy_to_user((char __user *)arg2, comm, - sizeof(comm))) - return -EFAULT; - break; - case PR_GET_ENDIAN: - error = GET_ENDIAN(me, arg2); - break; - case PR_SET_ENDIAN: - error = SET_ENDIAN(me, arg2); - break; - case PR_GET_SECCOMP: - error = prctl_get_seccomp(); - break; - case PR_SET_SECCOMP: - error = prctl_set_seccomp(arg2, (char __user *)arg3); - break; - case PR_GET_TSC: - error = GET_TSC_CTL(arg2); - break; - case PR_SET_TSC: - error = SET_TSC_CTL(arg2); - break; - case PR_TASK_PERF_EVENTS_DISABLE: - error = perf_event_task_disable(); - break; - case PR_TASK_PERF_EVENTS_ENABLE: - error = perf_event_task_enable(); - break; - case PR_GET_TIMERSLACK: - error = current->timer_slack_ns; - break; - case PR_SET_TIMERSLACK: - if (arg2 <= 0) - current->timer_slack_ns = + case PR_SET_UNALIGN: + error = SET_UNALIGN_CTL(me, arg2); + break; + case PR_GET_UNALIGN: + error = GET_UNALIGN_CTL(me, arg2); + break; + case PR_SET_FPEMU: + error = SET_FPEMU_CTL(me, arg2); + break; + case PR_GET_FPEMU: + error = GET_FPEMU_CTL(me, arg2); + break; + case PR_SET_FPEXC: + error = SET_FPEXC_CTL(me, arg2); + break; + case PR_GET_FPEXC: + error = GET_FPEXC_CTL(me, arg2); + break; + case PR_GET_TIMING: + error = PR_TIMING_STATISTICAL; + break; + case PR_SET_TIMING: + if (arg2 != PR_TIMING_STATISTICAL) + error = -EINVAL; + break; + case PR_SET_NAME: + comm[sizeof(me->comm) - 1] = 0; + if (strncpy_from_user(comm, (char __user *)arg2, + sizeof(me->comm) - 1) < 0) + return -EFAULT; + set_task_comm(me, comm); + proc_comm_connector(me); + break; + case PR_GET_NAME: + get_task_comm(comm, me); + if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) + return -EFAULT; + break; + case PR_GET_ENDIAN: + error = GET_ENDIAN(me, arg2); + break; + case PR_SET_ENDIAN: + error = SET_ENDIAN(me, arg2); + break; + case PR_GET_SECCOMP: + error = prctl_get_seccomp(); + break; + case PR_SET_SECCOMP: + error = prctl_set_seccomp(arg2, (char __user *)arg3); + break; + case PR_GET_TSC: + error = GET_TSC_CTL(arg2); + break; + case PR_SET_TSC: + error = SET_TSC_CTL(arg2); + break; + case PR_TASK_PERF_EVENTS_DISABLE: + error = perf_event_task_disable(); + break; + case PR_TASK_PERF_EVENTS_ENABLE: + error = perf_event_task_enable(); + break; + case PR_GET_TIMERSLACK: + error = current->timer_slack_ns; + break; + case PR_SET_TIMERSLACK: + if (arg2 <= 0) + current->timer_slack_ns = current->default_timer_slack_ns; - else - current->timer_slack_ns = arg2; - break; - case PR_MCE_KILL: - if (arg4 | arg5) - return -EINVAL; - switch (arg2) { - case PR_MCE_KILL_CLEAR: - if (arg3 != 0) - return -EINVAL; - current->flags &= ~PF_MCE_PROCESS; - break; - case PR_MCE_KILL_SET: - current->flags |= PF_MCE_PROCESS; - if (arg3 == PR_MCE_KILL_EARLY) - current->flags |= PF_MCE_EARLY; - else if (arg3 == PR_MCE_KILL_LATE) - current->flags &= ~PF_MCE_EARLY; - else if (arg3 == PR_MCE_KILL_DEFAULT) - current->flags &= - ~(PF_MCE_EARLY|PF_MCE_PROCESS); - else - return -EINVAL; - break; - default: + else + current->timer_slack_ns = arg2; + break; + case PR_MCE_KILL: + if (arg4 | arg5) + return -EINVAL; + switch (arg2) { + case PR_MCE_KILL_CLEAR: + if (arg3 != 0) return -EINVAL; - } + current->flags &= ~PF_MCE_PROCESS; break; - case PR_MCE_KILL_GET: - if (arg2 | arg3 | arg4 | arg5) - return -EINVAL; - if (current->flags & PF_MCE_PROCESS) - error = (current->flags & PF_MCE_EARLY) ? - PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; + case PR_MCE_KILL_SET: + current->flags |= PF_MCE_PROCESS; + if (arg3 == PR_MCE_KILL_EARLY) + current->flags |= PF_MCE_EARLY; + else if (arg3 == PR_MCE_KILL_LATE) + current->flags &= ~PF_MCE_EARLY; + else if (arg3 == PR_MCE_KILL_DEFAULT) + current->flags &= + ~(PF_MCE_EARLY|PF_MCE_PROCESS); else - error = PR_MCE_KILL_DEFAULT; - break; - case PR_SET_MM: - error = prctl_set_mm(arg2, arg3, arg4, arg5); - break; - case PR_GET_TID_ADDRESS: - error = prctl_get_tid_address(me, (int __user **)arg2); - break; - case PR_SET_CHILD_SUBREAPER: - me->signal->is_child_subreaper = !!arg2; - break; - case PR_GET_CHILD_SUBREAPER: - error = put_user(me->signal->is_child_subreaper, - (int __user *) arg2); - break; - case PR_SET_NO_NEW_PRIVS: - if (arg2 != 1 || arg3 || arg4 || arg5) return -EINVAL; - - current->no_new_privs = 1; break; - case PR_GET_NO_NEW_PRIVS: - if (arg2 || arg3 || arg4 || arg5) - return -EINVAL; - return current->no_new_privs ? 1 : 0; default: - error = -EINVAL; - break; + return -EINVAL; + } + break; + case PR_MCE_KILL_GET: + if (arg2 | arg3 | arg4 | arg5) + return -EINVAL; + if (current->flags & PF_MCE_PROCESS) + error = (current->flags & PF_MCE_EARLY) ? + PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; + else + error = PR_MCE_KILL_DEFAULT; + break; + case PR_SET_MM: + error = prctl_set_mm(arg2, arg3, arg4, arg5); + break; + case PR_GET_TID_ADDRESS: + error = prctl_get_tid_address(me, (int __user **)arg2); + break; + case PR_SET_CHILD_SUBREAPER: + me->signal->is_child_subreaper = !!arg2; + break; + case PR_GET_CHILD_SUBREAPER: + error = put_user(me->signal->is_child_subreaper, + (int __user *)arg2); + break; + case PR_SET_NO_NEW_PRIVS: + if (arg2 != 1 || arg3 || arg4 || arg5) + return -EINVAL; + + current->no_new_privs = 1; + break; + case PR_GET_NO_NEW_PRIVS: + if (arg2 || arg3 || arg4 || arg5) + return -EINVAL; + return current->no_new_privs ? 1 : 0; + default: + error = -EINVAL; + break; } return error; } @@ -2184,14 +2260,8 @@ SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; -static void argv_cleanup(struct subprocess_info *info) -{ - argv_free(info->argv); -} - -static int __orderly_poweroff(void) +static int __orderly_poweroff(bool force) { - int argc; char **argv; static char *envp[] = { "HOME=/", @@ -2200,21 +2270,40 @@ static int __orderly_poweroff(void) }; int ret; - argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); - if (argv == NULL) { + argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL); + if (argv) { + ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); + argv_free(argv); + } else { printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", - __func__, poweroff_cmd); - return -ENOMEM; + __func__, poweroff_cmd); + ret = -ENOMEM; } - ret = call_usermodehelper_fns(argv[0], argv, envp, UMH_WAIT_EXEC, - NULL, argv_cleanup, NULL); - if (ret == -ENOMEM) - argv_free(argv); + if (ret && force) { + printk(KERN_WARNING "Failed to start orderly shutdown: " + "forcing the issue\n"); + /* + * I guess this should try to kick off some daemon to sync and + * poweroff asap. Or not even bother syncing if we're doing an + * emergency shutdown? + */ + emergency_sync(); + kernel_power_off(); + } return ret; } +static bool poweroff_force; + +static void poweroff_work_func(struct work_struct *work) +{ + __orderly_poweroff(poweroff_force); +} + +static DECLARE_WORK(poweroff_work, poweroff_work_func); + /** * orderly_poweroff - Trigger an orderly system poweroff * @force: force poweroff if command execution fails @@ -2224,21 +2313,154 @@ static int __orderly_poweroff(void) */ int orderly_poweroff(bool force) { - int ret = __orderly_poweroff(); + if (force) /* do not override the pending "true" */ + poweroff_force = true; + schedule_work(&poweroff_work); + return 0; +} +EXPORT_SYMBOL_GPL(orderly_poweroff); - if (ret && force) { - printk(KERN_WARNING "Failed to start orderly shutdown: " - "forcing the issue\n"); +/** + * do_sysinfo - fill in sysinfo struct + * @info: pointer to buffer to fill + */ +static int do_sysinfo(struct sysinfo *info) +{ + unsigned long mem_total, sav_total; + unsigned int mem_unit, bitcount; + struct timespec tp; - /* - * I guess this should try to kick off some daemon to sync and - * poweroff asap. Or not even bother syncing if we're doing an - * emergency shutdown? - */ - emergency_sync(); - kernel_power_off(); + memset(info, 0, sizeof(struct sysinfo)); + + ktime_get_ts(&tp); + monotonic_to_bootbased(&tp); + info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); + + get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); + + info->procs = nr_threads; + + si_meminfo(info); + si_swapinfo(info); + + /* + * If the sum of all the available memory (i.e. ram + swap) + * is less than can be stored in a 32 bit unsigned long then + * we can be binary compatible with 2.2.x kernels. If not, + * well, in that case 2.2.x was broken anyways... + * + * -Erik Andersen <andersee@debian.org> + */ + + mem_total = info->totalram + info->totalswap; + if (mem_total < info->totalram || mem_total < info->totalswap) + goto out; + bitcount = 0; + mem_unit = info->mem_unit; + while (mem_unit > 1) { + bitcount++; + mem_unit >>= 1; + sav_total = mem_total; + mem_total <<= 1; + if (mem_total < sav_total) + goto out; } - return ret; + /* + * If mem_total did not overflow, multiply all memory values by + * info->mem_unit and set it to 1. This leaves things compatible + * with 2.2.x, and also retains compatibility with earlier 2.4.x + * kernels... + */ + + info->mem_unit = 1; + info->totalram <<= bitcount; + info->freeram <<= bitcount; + info->sharedram <<= bitcount; + info->bufferram <<= bitcount; + info->totalswap <<= bitcount; + info->freeswap <<= bitcount; + info->totalhigh <<= bitcount; + info->freehigh <<= bitcount; + +out: + return 0; } -EXPORT_SYMBOL_GPL(orderly_poweroff); + +SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) +{ + struct sysinfo val; + + do_sysinfo(&val); + + if (copy_to_user(info, &val, sizeof(struct sysinfo))) + return -EFAULT; + + return 0; +} + +#ifdef CONFIG_COMPAT +struct compat_sysinfo { + s32 uptime; + u32 loads[3]; + u32 totalram; + u32 freeram; + u32 sharedram; + u32 bufferram; + u32 totalswap; + u32 freeswap; + u16 procs; + u16 pad; + u32 totalhigh; + u32 freehigh; + u32 mem_unit; + char _f[20-2*sizeof(u32)-sizeof(int)]; +}; + +COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) +{ + struct sysinfo s; + + do_sysinfo(&s); + + /* Check to see if any memory value is too large for 32-bit and scale + * down if needed + */ + if ((s.totalram >> 32) || (s.totalswap >> 32)) { + int bitcount = 0; + + while (s.mem_unit < PAGE_SIZE) { + s.mem_unit <<= 1; + bitcount++; + } + + s.totalram >>= bitcount; + s.freeram >>= bitcount; + s.sharedram >>= bitcount; + s.bufferram >>= bitcount; + s.totalswap >>= bitcount; + s.freeswap >>= bitcount; + s.totalhigh >>= bitcount; + s.freehigh >>= bitcount; + } + + if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) || + __put_user(s.uptime, &info->uptime) || + __put_user(s.loads[0], &info->loads[0]) || + __put_user(s.loads[1], &info->loads[1]) || + __put_user(s.loads[2], &info->loads[2]) || + __put_user(s.totalram, &info->totalram) || + __put_user(s.freeram, &info->freeram) || + __put_user(s.sharedram, &info->sharedram) || + __put_user(s.bufferram, &info->bufferram) || + __put_user(s.totalswap, &info->totalswap) || + __put_user(s.freeswap, &info->freeswap) || + __put_user(s.procs, &info->procs) || + __put_user(s.totalhigh, &info->totalhigh) || + __put_user(s.freehigh, &info->freehigh) || + __put_user(s.mem_unit, &info->mem_unit)) + return -EFAULT; + + return 0; +} +#endif /* CONFIG_COMPAT */ diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 395084d4ce16..7078052284fd 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -20,6 +20,7 @@ cond_syscall(sys_quotactl); cond_syscall(sys32_quotactl); cond_syscall(sys_acct); cond_syscall(sys_lookup_dcookie); +cond_syscall(compat_sys_lookup_dcookie); cond_syscall(sys_swapon); cond_syscall(sys_swapoff); cond_syscall(sys_kexec_load); @@ -155,7 +156,7 @@ cond_syscall(compat_sys_process_vm_writev); cond_syscall(sys_pciconfig_read); cond_syscall(sys_pciconfig_write); cond_syscall(sys_pciconfig_iobase); -cond_syscall(sys32_ipc); +cond_syscall(compat_sys_s390_ipc); cond_syscall(ppc_rtas); cond_syscall(sys_spu_run); cond_syscall(sys_spu_create); @@ -199,6 +200,7 @@ cond_syscall(sys_perf_event_open); /* fanotify! */ cond_syscall(sys_fanotify_init); cond_syscall(sys_fanotify_mark); +cond_syscall(compat_sys_fanotify_mark); /* open by handle */ cond_syscall(sys_name_to_handle_at); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index c88878db491e..9edcf456e0fc 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -61,6 +61,7 @@ #include <linux/kmod.h> #include <linux/capability.h> #include <linux/binfmts.h> +#include <linux/sched/sysctl.h> #include <asm/uaccess.h> #include <asm/processor.h> @@ -104,9 +105,7 @@ extern char core_pattern[]; extern unsigned int core_pipe_limit; #endif extern int pid_max; -extern int min_free_kbytes; extern int pid_max_min, pid_max_max; -extern int sysctl_drop_caches; extern int percpu_pagelist_fraction; extern int compat_log; extern int latencytop_enabled; @@ -157,14 +156,20 @@ extern int sysctl_tsb_ratio; #ifdef __hppa__ extern int pwrsw_enabled; +#endif + +#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW extern int unaligned_enabled; #endif #ifdef CONFIG_IA64 -extern int no_unaligned_warning; extern int unaligned_dump_stack; #endif +#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN +extern int no_unaligned_warning; +#endif + #ifdef CONFIG_PROC_SYSCTL static int proc_do_cad_pid(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); @@ -403,6 +408,13 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = sched_rt_handler, }, + { + .procname = "sched_rr_timeslice_ms", + .data = &sched_rr_timeslice, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = sched_rr_handler, + }, #ifdef CONFIG_SCHED_AUTOGROUP { .procname = "sched_autogroup_enabled", @@ -545,6 +557,8 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, +#endif +#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW { .procname = "unaligned-trap", .data = &unaligned_enabled, @@ -911,7 +925,7 @@ static struct ctl_table kern_table[] = { .proc_handler = proc_doulongvec_minmax, }, #endif -#ifdef CONFIG_IA64 +#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN { .procname = "ignore-unaligned-usertrap", .data = &no_unaligned_warning, @@ -919,6 +933,8 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, +#endif +#ifdef CONFIG_IA64 { .procname = "unaligned-dump-stack", .data = &unaligned_dump_stack, @@ -1413,6 +1429,20 @@ static struct ctl_table vm_table[] = { .extra2 = &one, }, #endif + { + .procname = "user_reserve_kbytes", + .data = &sysctl_user_reserve_kbytes, + .maxlen = sizeof(sysctl_user_reserve_kbytes), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + }, + { + .procname = "admin_reserve_kbytes", + .data = &sysctl_admin_reserve_kbytes, + .maxlen = sizeof(sysctl_admin_reserve_kbytes), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + }, { } }; @@ -2006,7 +2036,7 @@ static int proc_taint(struct ctl_table *table, int write, int i; for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) { if ((tmptaint >> i) & 1) - add_taint(i); + add_taint(i, LOCKDEP_STILL_OK); } } @@ -2083,7 +2113,7 @@ int proc_dointvec_minmax(struct ctl_table *table, int write, static void validate_coredump_safety(void) { #ifdef CONFIG_COREDUMP - if (suid_dumpable == SUID_DUMPABLE_SAFE && + if (suid_dumpable == SUID_DUMP_ROOT && core_pattern[0] != '/' && core_pattern[0] != '|') { printk(KERN_WARNING "Unsafe core_pattern used with "\ "suid_dumpable=2. Pipe handler or fully qualified "\ diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c index 5a6384450501..aea4a9ea6fc8 100644 --- a/kernel/sysctl_binary.c +++ b/kernel/sysctl_binary.c @@ -15,6 +15,7 @@ #include <linux/netdevice.h> #include <linux/kernel.h> #include <linux/slab.h> +#include <linux/compat.h> #ifdef CONFIG_SYSCTL_SYSCALL @@ -387,7 +388,6 @@ static const struct bin_table bin_net_ipv4_table[] = { { CTL_INT, NET_TCP_MODERATE_RCVBUF, "tcp_moderate_rcvbuf" }, { CTL_INT, NET_TCP_TSO_WIN_DIVISOR, "tcp_tso_win_divisor" }, { CTL_STR, NET_TCP_CONG_CONTROL, "tcp_congestion_control" }, - { CTL_INT, NET_TCP_ABC, "tcp_abc" }, { CTL_INT, NET_TCP_MTU_PROBING, "tcp_mtu_probing" }, { CTL_INT, NET_TCP_BASE_MSS, "tcp_base_mss" }, { CTL_INT, NET_IPV4_TCP_WORKAROUND_SIGNED_WINDOWS, "tcp_workaround_signed_windows" }, @@ -971,7 +971,6 @@ out: static ssize_t bin_intvec(struct file *file, void __user *oldval, size_t oldlen, void __user *newval, size_t newlen) { - mm_segment_t old_fs = get_fs(); ssize_t copied = 0; char *buffer; ssize_t result; @@ -984,13 +983,10 @@ static ssize_t bin_intvec(struct file *file, if (oldval && oldlen) { unsigned __user *vec = oldval; size_t length = oldlen / sizeof(*vec); - loff_t pos = 0; char *str, *end; int i; - set_fs(KERNEL_DS); - result = vfs_read(file, buffer, BUFSZ - 1, &pos); - set_fs(old_fs); + result = kernel_read(file, 0, buffer, BUFSZ - 1); if (result < 0) goto out_kfree; @@ -1017,7 +1013,6 @@ static ssize_t bin_intvec(struct file *file, if (newval && newlen) { unsigned __user *vec = newval; size_t length = newlen / sizeof(*vec); - loff_t pos = 0; char *str, *end; int i; @@ -1033,9 +1028,7 @@ static ssize_t bin_intvec(struct file *file, str += snprintf(str, end - str, "%lu\t", value); } - set_fs(KERNEL_DS); - result = vfs_write(file, buffer, str - buffer, &pos); - set_fs(old_fs); + result = kernel_write(file, buffer, str - buffer, 0); if (result < 0) goto out_kfree; } @@ -1049,7 +1042,6 @@ out: static ssize_t bin_ulongvec(struct file *file, void __user *oldval, size_t oldlen, void __user *newval, size_t newlen) { - mm_segment_t old_fs = get_fs(); ssize_t copied = 0; char *buffer; ssize_t result; @@ -1062,13 +1054,10 @@ static ssize_t bin_ulongvec(struct file *file, if (oldval && oldlen) { unsigned long __user *vec = oldval; size_t length = oldlen / sizeof(*vec); - loff_t pos = 0; char *str, *end; int i; - set_fs(KERNEL_DS); - result = vfs_read(file, buffer, BUFSZ - 1, &pos); - set_fs(old_fs); + result = kernel_read(file, 0, buffer, BUFSZ - 1); if (result < 0) goto out_kfree; @@ -1095,7 +1084,6 @@ static ssize_t bin_ulongvec(struct file *file, if (newval && newlen) { unsigned long __user *vec = newval; size_t length = newlen / sizeof(*vec); - loff_t pos = 0; char *str, *end; int i; @@ -1111,9 +1099,7 @@ static ssize_t bin_ulongvec(struct file *file, str += snprintf(str, end - str, "%lu\t", value); } - set_fs(KERNEL_DS); - result = vfs_write(file, buffer, str - buffer, &pos); - set_fs(old_fs); + result = kernel_write(file, buffer, str - buffer, 0); if (result < 0) goto out_kfree; } @@ -1127,19 +1113,15 @@ out: static ssize_t bin_uuid(struct file *file, void __user *oldval, size_t oldlen, void __user *newval, size_t newlen) { - mm_segment_t old_fs = get_fs(); ssize_t result, copied = 0; /* Only supports reads */ if (oldval && oldlen) { - loff_t pos = 0; char buf[40], *str = buf; unsigned char uuid[16]; int i; - set_fs(KERNEL_DS); - result = vfs_read(file, buf, sizeof(buf) - 1, &pos); - set_fs(old_fs); + result = kernel_read(file, 0, buf, sizeof(buf) - 1); if (result < 0) goto out; @@ -1175,18 +1157,14 @@ out: static ssize_t bin_dn_node_address(struct file *file, void __user *oldval, size_t oldlen, void __user *newval, size_t newlen) { - mm_segment_t old_fs = get_fs(); ssize_t result, copied = 0; if (oldval && oldlen) { - loff_t pos = 0; char buf[15], *nodep; unsigned long area, node; __le16 dnaddr; - set_fs(KERNEL_DS); - result = vfs_read(file, buf, sizeof(buf) - 1, &pos); - set_fs(old_fs); + result = kernel_read(file, 0, buf, sizeof(buf) - 1); if (result < 0) goto out; @@ -1194,9 +1172,10 @@ static ssize_t bin_dn_node_address(struct file *file, /* Convert the decnet address to binary */ result = -EIO; - nodep = strchr(buf, '.') + 1; + nodep = strchr(buf, '.'); if (!nodep) goto out; + ++nodep; area = simple_strtoul(buf, NULL, 10); node = simple_strtoul(nodep, NULL, 10); @@ -1215,7 +1194,6 @@ static ssize_t bin_dn_node_address(struct file *file, } if (newval && newlen) { - loff_t pos = 0; __le16 dnaddr; char buf[15]; int len; @@ -1232,9 +1210,7 @@ static ssize_t bin_dn_node_address(struct file *file, le16_to_cpu(dnaddr) >> 10, le16_to_cpu(dnaddr) & 0x3ff); - set_fs(KERNEL_DS); - result = vfs_write(file, buf, len, &pos); - set_fs(old_fs); + result = kernel_write(file, buf, len, 0); if (result < 0) goto out; } @@ -1472,7 +1448,6 @@ SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args) #ifdef CONFIG_COMPAT -#include <asm/compat.h> struct compat_sysctl_args { compat_uptr_t name; @@ -1484,7 +1459,7 @@ struct compat_sysctl_args { compat_ulong_t __unused[4]; }; -asmlinkage long compat_sys_sysctl(struct compat_sysctl_args __user *args) +COMPAT_SYSCALL_DEFINE1(sysctl, struct compat_sysctl_args __user *, args) { struct compat_sysctl_args tmp; compat_size_t __user *compat_oldlenp; diff --git a/kernel/test_kprobes.c b/kernel/test_kprobes.c index f8b11a283171..12d6ebbfdd83 100644 --- a/kernel/test_kprobes.c +++ b/kernel/test_kprobes.c @@ -365,7 +365,7 @@ int init_test_probes(void) target2 = kprobe_target2; do { - rand1 = random32(); + rand1 = prandom_u32(); } while (rand1 <= div_factor); printk(KERN_INFO "Kprobe smoke test started\n"); diff --git a/kernel/time.c b/kernel/time.c index d226c6a3fd28..d3617dbd3dca 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -115,6 +115,12 @@ SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv, } /* + * Indicates if there is an offset between the system clock and the hardware + * clock/persistent clock/rtc. + */ +int persistent_clock_is_local; + +/* * Adjust the time obtained from the CMOS to be UTC time instead of * local time. * @@ -132,11 +138,14 @@ SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv, */ static inline void warp_clock(void) { - struct timespec adjust; + if (sys_tz.tz_minuteswest != 0) { + struct timespec adjust; - adjust = current_kernel_time(); - adjust.tv_sec += sys_tz.tz_minuteswest * 60; - do_settimeofday(&adjust); + persistent_clock_is_local = 1; + adjust.tv_sec = sys_tz.tz_minuteswest * 60; + adjust.tv_nsec = 0; + timekeeping_inject_offset(&adjust); + } } /* @@ -232,7 +241,7 @@ EXPORT_SYMBOL(current_fs_time); * Avoid unnecessary multiplications/divisions in the * two most common HZ cases: */ -inline unsigned int jiffies_to_msecs(const unsigned long j) +unsigned int jiffies_to_msecs(const unsigned long j) { #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) return (MSEC_PER_SEC / HZ) * j; @@ -248,7 +257,7 @@ inline unsigned int jiffies_to_msecs(const unsigned long j) } EXPORT_SYMBOL(jiffies_to_msecs); -inline unsigned int jiffies_to_usecs(const unsigned long j) +unsigned int jiffies_to_usecs(const unsigned long j) { #if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ) return (USEC_PER_SEC / HZ) * j; diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index 8601f0db1261..e4c07b0692bb 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -12,6 +12,11 @@ config CLOCKSOURCE_WATCHDOG config ARCH_CLOCKSOURCE_DATA bool +# Platforms has a persistent clock +config ALWAYS_USE_PERSISTENT_CLOCK + bool + default n + # Timekeeping vsyscall support config GENERIC_TIME_VSYSCALL bool @@ -38,6 +43,10 @@ config GENERIC_CLOCKEVENTS_BUILD default y depends on GENERIC_CLOCKEVENTS +# Architecture can handle broadcast in a driver-agnostic way +config ARCH_HAS_TICK_BROADCAST + bool + # Clockevents broadcasting infrastructure config GENERIC_CLOCKEVENTS_BROADCAST bool @@ -55,20 +64,88 @@ config GENERIC_CMOS_UPDATE if GENERIC_CLOCKEVENTS menu "Timers subsystem" -# Core internal switch. Selected by NO_HZ / HIGH_RES_TIMERS. This is +# Core internal switch. Selected by NO_HZ_COMMON / HIGH_RES_TIMERS. This is # only related to the tick functionality. Oneshot clockevent devices # are supported independ of this. config TICK_ONESHOT bool -config NO_HZ - bool "Tickless System (Dynamic Ticks)" +config NO_HZ_COMMON + bool depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS select TICK_ONESHOT + +choice + prompt "Timer tick handling" + default NO_HZ_IDLE if NO_HZ + +config HZ_PERIODIC + bool "Periodic timer ticks (constant rate, no dynticks)" + help + This option keeps the tick running periodically at a constant + rate, even when the CPU doesn't need it. + +config NO_HZ_IDLE + bool "Idle dynticks system (tickless idle)" + depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS + select NO_HZ_COMMON + help + This option enables a tickless idle system: timer interrupts + will only trigger on an as-needed basis when the system is idle. + This is usually interesting for energy saving. + + Most of the time you want to say Y here. + +config NO_HZ_FULL + bool "Full dynticks system (tickless)" + # NO_HZ_COMMON dependency + depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS + # We need at least one periodic CPU for timekeeping + depends on SMP + # RCU_USER_QS dependency + depends on HAVE_CONTEXT_TRACKING + # VIRT_CPU_ACCOUNTING_GEN dependency + depends on 64BIT + select NO_HZ_COMMON + select RCU_USER_QS + select RCU_NOCB_CPU + select VIRT_CPU_ACCOUNTING_GEN + select CONTEXT_TRACKING_FORCE + select IRQ_WORK + help + Adaptively try to shutdown the tick whenever possible, even when + the CPU is running tasks. Typically this requires running a single + task on the CPU. Chances for running tickless are maximized when + the task mostly runs in userspace and has few kernel activity. + + You need to fill up the nohz_full boot parameter with the + desired range of dynticks CPUs. + + This is implemented at the expense of some overhead in user <-> kernel + transitions: syscalls, exceptions and interrupts. Even when it's + dynamically off. + + Say N. + +endchoice + +config NO_HZ_FULL_ALL + bool "Full dynticks system on all CPUs by default" + depends on NO_HZ_FULL + help + If the user doesn't pass the nohz_full boot option to + define the range of full dynticks CPUs, consider that all + CPUs in the system are full dynticks by default. + Note the boot CPU will still be kept outside the range to + handle the timekeeping duty. + +config NO_HZ + bool "Old Idle dynticks config" + depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS help - This option enables a tickless system: timer interrupts will - only trigger on an as-needed basis both when the system is - busy and when the system is idle. + This is the old config entry that enables dynticks idle. + We keep it around for a little while to enforce backward + compatibility with older config files. config HIGH_RES_TIMERS bool "High Resolution Timer Support" diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 30b6de0d977c..c6d6400ee137 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -339,6 +339,7 @@ void clockevents_config_and_register(struct clock_event_device *dev, clockevents_config(dev, freq); clockevents_register_device(dev); } +EXPORT_SYMBOL_GPL(clockevents_config_and_register); /** * clockevents_update_freq - Update frequency and reprogram a clock event device. diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 24174b4d669b..12ff13a838c6 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -15,15 +15,17 @@ #include <linux/time.h> #include <linux/mm.h> #include <linux/module.h> +#include <linux/rtc.h> #include "tick-internal.h" +#include "ntp_internal.h" /* * NTP timekeeping variables: + * + * Note: All of the NTP state is protected by the timekeeping locks. */ -DEFINE_SPINLOCK(ntp_lock); - /* USER_HZ period (usecs): */ unsigned long tick_usec = TICK_USEC; @@ -52,9 +54,6 @@ static int time_state = TIME_OK; /* clock status bits: */ static int time_status = STA_UNSYNC; -/* TAI offset (secs): */ -static long time_tai; - /* time adjustment (nsecs): */ static s64 time_offset; @@ -133,8 +132,6 @@ static inline void pps_reset_freq_interval(void) /** * pps_clear - Clears the PPS state variables - * - * Must be called while holding a write on the ntp_lock */ static inline void pps_clear(void) { @@ -149,8 +146,6 @@ static inline void pps_clear(void) /* Decrease pps_valid to indicate that another second has passed since * the last PPS signal. When it reaches 0, indicate that PPS signal is * missing. - * - * Must be called while holding a write on the ntp_lock */ static inline void pps_dec_valid(void) { @@ -345,10 +340,6 @@ static void ntp_update_offset(long offset) */ void ntp_clear(void) { - unsigned long flags; - - spin_lock_irqsave(&ntp_lock, flags); - time_adjust = 0; /* stop active adjtime() */ time_status |= STA_UNSYNC; time_maxerror = NTP_PHASE_LIMIT; @@ -361,20 +352,12 @@ void ntp_clear(void) /* Clear PPS state variables */ pps_clear(); - spin_unlock_irqrestore(&ntp_lock, flags); - } u64 ntp_tick_length(void) { - unsigned long flags; - s64 ret; - - spin_lock_irqsave(&ntp_lock, flags); - ret = tick_length; - spin_unlock_irqrestore(&ntp_lock, flags); - return ret; + return tick_length; } @@ -392,9 +375,6 @@ int second_overflow(unsigned long secs) { s64 delta; int leap = 0; - unsigned long flags; - - spin_lock_irqsave(&ntp_lock, flags); /* * Leap second processing. If in leap-insert state at the end of the @@ -414,7 +394,6 @@ int second_overflow(unsigned long secs) else if (secs % 86400 == 0) { leap = -1; time_state = TIME_OOP; - time_tai++; printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n"); } @@ -424,7 +403,6 @@ int second_overflow(unsigned long secs) time_state = TIME_OK; else if ((secs + 1) % 86400 == 0) { leap = 1; - time_tai--; time_state = TIME_WAIT; printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n"); @@ -478,13 +456,10 @@ int second_overflow(unsigned long secs) time_adjust = 0; out: - spin_unlock_irqrestore(&ntp_lock, flags); - return leap; } -#ifdef CONFIG_GENERIC_CMOS_UPDATE - +#if defined(CONFIG_GENERIC_CMOS_UPDATE) || defined(CONFIG_RTC_SYSTOHC) static void sync_cmos_clock(struct work_struct *work); static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock); @@ -510,14 +485,26 @@ static void sync_cmos_clock(struct work_struct *work) } getnstimeofday(&now); - if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) - fail = update_persistent_clock(now); + if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) { + struct timespec adjust = now; + + fail = -ENODEV; + if (persistent_clock_is_local) + adjust.tv_sec -= (sys_tz.tz_minuteswest * 60); +#ifdef CONFIG_GENERIC_CMOS_UPDATE + fail = update_persistent_clock(adjust); +#endif +#ifdef CONFIG_RTC_SYSTOHC + if (fail == -ENODEV) + fail = rtc_set_ntp_time(adjust); +#endif + } next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2); if (next.tv_nsec <= 0) next.tv_nsec += NSEC_PER_SEC; - if (!fail) + if (!fail || fail == -ENODEV) next.tv_sec = 659; else next.tv_sec = 0; @@ -563,11 +550,10 @@ static inline void process_adj_status(struct timex *txc, struct timespec *ts) time_status |= txc->status & ~STA_RONLY; } -/* - * Called with ntp_lock held, so we can access and modify - * all the global NTP state: - */ -static inline void process_adjtimex_modes(struct timex *txc, struct timespec *ts) + +static inline void process_adjtimex_modes(struct timex *txc, + struct timespec *ts, + s32 *time_tai) { if (txc->modes & ADJ_STATUS) process_adj_status(txc, ts); @@ -601,7 +587,7 @@ static inline void process_adjtimex_modes(struct timex *txc, struct timespec *ts } if (txc->modes & ADJ_TAI && txc->constant > 0) - time_tai = txc->constant; + *time_tai = txc->constant; if (txc->modes & ADJ_OFFSET) ntp_update_offset(txc->offset); @@ -613,16 +599,13 @@ static inline void process_adjtimex_modes(struct timex *txc, struct timespec *ts ntp_update_frequency(); } -/* - * adjtimex mainly allows reading (and writing, if superuser) of - * kernel time-keeping variables. used by xntpd. + + +/** + * ntp_validate_timex - Ensures the timex is ok for use in do_adjtimex */ -int do_adjtimex(struct timex *txc) +int ntp_validate_timex(struct timex *txc) { - struct timespec ts; - int result; - - /* Validate the data before disabling interrupts */ if (txc->modes & ADJ_ADJTIME) { /* singleshot must not be used with any other mode bits */ if (!(txc->modes & ADJ_OFFSET_SINGLESHOT)) @@ -634,7 +617,6 @@ int do_adjtimex(struct timex *txc) /* In order to modify anything, you gotta be super-user! */ if (txc->modes && !capable(CAP_SYS_TIME)) return -EPERM; - /* * if the quartz is off by more than 10% then * something is VERY wrong! @@ -645,22 +627,20 @@ int do_adjtimex(struct timex *txc) return -EINVAL; } - if (txc->modes & ADJ_SETOFFSET) { - struct timespec delta; - delta.tv_sec = txc->time.tv_sec; - delta.tv_nsec = txc->time.tv_usec; - if (!capable(CAP_SYS_TIME)) - return -EPERM; - if (!(txc->modes & ADJ_NANO)) - delta.tv_nsec *= 1000; - result = timekeeping_inject_offset(&delta); - if (result) - return result; - } + if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME))) + return -EPERM; - getnstimeofday(&ts); + return 0; +} - spin_lock_irq(&ntp_lock); + +/* + * adjtimex mainly allows reading (and writing, if superuser) of + * kernel time-keeping variables. used by xntpd. + */ +int __do_adjtimex(struct timex *txc, struct timespec *ts, s32 *time_tai) +{ + int result; if (txc->modes & ADJ_ADJTIME) { long save_adjust = time_adjust; @@ -675,7 +655,7 @@ int do_adjtimex(struct timex *txc) /* If there are input parameters, then process them: */ if (txc->modes) - process_adjtimex_modes(txc, &ts); + process_adjtimex_modes(txc, ts, time_tai); txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ, NTP_SCALE_SHIFT); @@ -697,15 +677,13 @@ int do_adjtimex(struct timex *txc) txc->precision = 1; txc->tolerance = MAXFREQ_SCALED / PPM_SCALE; txc->tick = tick_usec; - txc->tai = time_tai; + txc->tai = *time_tai; /* fill PPS status fields */ pps_fill_timex(txc); - spin_unlock_irq(&ntp_lock); - - txc->time.tv_sec = ts.tv_sec; - txc->time.tv_usec = ts.tv_nsec; + txc->time.tv_sec = ts->tv_sec; + txc->time.tv_usec = ts->tv_nsec; if (!(time_status & STA_NANO)) txc->time.tv_usec /= NSEC_PER_USEC; @@ -882,7 +860,7 @@ static void hardpps_update_phase(long error) } /* - * hardpps() - discipline CPU clock oscillator to external PPS signal + * __hardpps() - discipline CPU clock oscillator to external PPS signal * * This routine is called at each PPS signal arrival in order to * discipline the CPU clock oscillator to the PPS signal. It takes two @@ -893,15 +871,13 @@ static void hardpps_update_phase(long error) * This code is based on David Mills's reference nanokernel * implementation. It was mostly rewritten but keeps the same idea. */ -void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) +void __hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) { struct pps_normtime pts_norm, freq_norm; unsigned long flags; pts_norm = pps_normalize_ts(*phase_ts); - spin_lock_irqsave(&ntp_lock, flags); - /* clear the error bits, they will be set again if needed */ time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR); @@ -913,7 +889,6 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) * just start the frequency interval */ if (unlikely(pps_fbase.tv_sec == 0)) { pps_fbase = *raw_ts; - spin_unlock_irqrestore(&ntp_lock, flags); return; } @@ -928,7 +903,6 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) time_status |= STA_PPSJITTER; /* restart the frequency calibration interval */ pps_fbase = *raw_ts; - spin_unlock_irqrestore(&ntp_lock, flags); pr_err("hardpps: PPSJITTER: bad pulse\n"); return; } @@ -945,10 +919,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) hardpps_update_phase(pts_norm.nsec); - spin_unlock_irqrestore(&ntp_lock, flags); } -EXPORT_SYMBOL(hardpps); - #endif /* CONFIG_NTP_PPS */ static int __init ntp_tick_adj_setup(char *str) diff --git a/kernel/time/ntp_internal.h b/kernel/time/ntp_internal.h new file mode 100644 index 000000000000..1950cb4ca2a4 --- /dev/null +++ b/kernel/time/ntp_internal.h @@ -0,0 +1,12 @@ +#ifndef _LINUX_NTP_INTERNAL_H +#define _LINUX_NTP_INTERNAL_H + +extern void ntp_init(void); +extern void ntp_clear(void); +/* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */ +extern u64 ntp_tick_length(void); +extern int second_overflow(unsigned long secs); +extern int ntp_validate_timex(struct timex *); +extern int __do_adjtimex(struct timex *, struct timespec *, s32 *); +extern void __hardpps(const struct timespec *, const struct timespec *); +#endif /* _LINUX_NTP_INTERNAL_H */ diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index f113755695e2..206bbfb34e09 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -18,6 +18,7 @@ #include <linux/percpu.h> #include <linux/profile.h> #include <linux/sched.h> +#include <linux/smp.h> #include "tick-internal.h" @@ -27,9 +28,8 @@ */ static struct tick_device tick_broadcast_device; -/* FIXME: Use cpumask_var_t. */ -static DECLARE_BITMAP(tick_broadcast_mask, NR_CPUS); -static DECLARE_BITMAP(tmpmask, NR_CPUS); +static cpumask_var_t tick_broadcast_mask; +static cpumask_var_t tmpmask; static DEFINE_RAW_SPINLOCK(tick_broadcast_lock); static int tick_broadcast_force; @@ -49,7 +49,7 @@ struct tick_device *tick_get_broadcast_device(void) struct cpumask *tick_get_broadcast_mask(void) { - return to_cpumask(tick_broadcast_mask); + return tick_broadcast_mask; } /* @@ -66,15 +66,30 @@ static void tick_broadcast_start_periodic(struct clock_event_device *bc) */ int tick_check_broadcast_device(struct clock_event_device *dev) { - if ((tick_broadcast_device.evtdev && + struct clock_event_device *cur = tick_broadcast_device.evtdev; + + if ((dev->features & CLOCK_EVT_FEAT_DUMMY) || + (tick_broadcast_device.evtdev && tick_broadcast_device.evtdev->rating >= dev->rating) || (dev->features & CLOCK_EVT_FEAT_C3STOP)) return 0; clockevents_exchange_device(tick_broadcast_device.evtdev, dev); + if (cur) + cur->event_handler = clockevents_handle_noop; tick_broadcast_device.evtdev = dev; - if (!cpumask_empty(tick_get_broadcast_mask())) + if (!cpumask_empty(tick_broadcast_mask)) tick_broadcast_start_periodic(dev); + /* + * Inform all cpus about this. We might be in a situation + * where we did not switch to oneshot mode because the per cpu + * devices are affected by CLOCK_EVT_FEAT_C3STOP and the lack + * of a oneshot capable broadcast device. Without that + * notification the systems stays stuck in periodic mode + * forever. + */ + if (dev->features & CLOCK_EVT_FEAT_ONESHOT) + tick_clock_notify(); return 1; } @@ -86,6 +101,22 @@ int tick_is_broadcast_device(struct clock_event_device *dev) return (dev && tick_broadcast_device.evtdev == dev); } +static void err_broadcast(const struct cpumask *mask) +{ + pr_crit_once("Failed to broadcast timer tick. Some CPUs may be unresponsive.\n"); +} + +static void tick_device_setup_broadcast_func(struct clock_event_device *dev) +{ + if (!dev->broadcast) + dev->broadcast = tick_broadcast; + if (!dev->broadcast) { + pr_warn_once("%s depends on broadcast, but no broadcast function available\n", + dev->name); + dev->broadcast = err_broadcast; + } +} + /* * Check, if the device is disfunctional and a place holder, which * needs to be handled by the broadcast device. @@ -105,7 +136,8 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) */ if (!tick_device_is_functional(dev)) { dev->event_handler = tick_handle_periodic; - cpumask_set_cpu(cpu, tick_get_broadcast_mask()); + tick_device_setup_broadcast_func(dev); + cpumask_set_cpu(cpu, tick_broadcast_mask); tick_broadcast_start_periodic(tick_broadcast_device.evtdev); ret = 1; } else { @@ -116,15 +148,33 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) */ if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) { int cpu = smp_processor_id(); - - cpumask_clear_cpu(cpu, tick_get_broadcast_mask()); + cpumask_clear_cpu(cpu, tick_broadcast_mask); tick_broadcast_clear_oneshot(cpu); + } else { + tick_device_setup_broadcast_func(dev); } } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); return ret; } +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST +int tick_receive_broadcast(void) +{ + struct tick_device *td = this_cpu_ptr(&tick_cpu_device); + struct clock_event_device *evt = td->evtdev; + + if (!evt) + return -ENODEV; + + if (!evt->event_handler) + return -EINVAL; + + evt->event_handler(evt); + return 0; +} +#endif + /* * Broadcast the event to the cpus, which are set in the mask (mangled). */ @@ -162,9 +212,8 @@ static void tick_do_periodic_broadcast(void) { raw_spin_lock(&tick_broadcast_lock); - cpumask_and(to_cpumask(tmpmask), - cpu_online_mask, tick_get_broadcast_mask()); - tick_do_broadcast(to_cpumask(tmpmask)); + cpumask_and(tmpmask, cpu_online_mask, tick_broadcast_mask); + tick_do_broadcast(tmpmask); raw_spin_unlock(&tick_broadcast_lock); } @@ -227,13 +276,12 @@ static void tick_do_broadcast_on_off(unsigned long *reason) if (!tick_device_is_functional(dev)) goto out; - bc_stopped = cpumask_empty(tick_get_broadcast_mask()); + bc_stopped = cpumask_empty(tick_broadcast_mask); switch (*reason) { case CLOCK_EVT_NOTIFY_BROADCAST_ON: case CLOCK_EVT_NOTIFY_BROADCAST_FORCE: - if (!cpumask_test_cpu(cpu, tick_get_broadcast_mask())) { - cpumask_set_cpu(cpu, tick_get_broadcast_mask()); + if (!cpumask_test_and_set_cpu(cpu, tick_broadcast_mask)) { if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) clockevents_shutdown(dev); @@ -243,8 +291,7 @@ static void tick_do_broadcast_on_off(unsigned long *reason) break; case CLOCK_EVT_NOTIFY_BROADCAST_OFF: if (!tick_broadcast_force && - cpumask_test_cpu(cpu, tick_get_broadcast_mask())) { - cpumask_clear_cpu(cpu, tick_get_broadcast_mask()); + cpumask_test_and_clear_cpu(cpu, tick_broadcast_mask)) { if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) tick_setup_periodic(dev, 0); @@ -252,7 +299,7 @@ static void tick_do_broadcast_on_off(unsigned long *reason) break; } - if (cpumask_empty(tick_get_broadcast_mask())) { + if (cpumask_empty(tick_broadcast_mask)) { if (!bc_stopped) clockevents_shutdown(bc); } else if (bc_stopped) { @@ -301,10 +348,10 @@ void tick_shutdown_broadcast(unsigned int *cpup) raw_spin_lock_irqsave(&tick_broadcast_lock, flags); bc = tick_broadcast_device.evtdev; - cpumask_clear_cpu(cpu, tick_get_broadcast_mask()); + cpumask_clear_cpu(cpu, tick_broadcast_mask); if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) { - if (bc && cpumask_empty(tick_get_broadcast_mask())) + if (bc && cpumask_empty(tick_broadcast_mask)) clockevents_shutdown(bc); } @@ -340,13 +387,13 @@ int tick_resume_broadcast(void) switch (tick_broadcast_device.mode) { case TICKDEV_MODE_PERIODIC: - if (!cpumask_empty(tick_get_broadcast_mask())) + if (!cpumask_empty(tick_broadcast_mask)) tick_broadcast_start_periodic(bc); broadcast = cpumask_test_cpu(smp_processor_id(), - tick_get_broadcast_mask()); + tick_broadcast_mask); break; case TICKDEV_MODE_ONESHOT: - if (!cpumask_empty(tick_get_broadcast_mask())) + if (!cpumask_empty(tick_broadcast_mask)) broadcast = tick_resume_broadcast_oneshot(bc); break; } @@ -359,25 +406,58 @@ int tick_resume_broadcast(void) #ifdef CONFIG_TICK_ONESHOT -/* FIXME: use cpumask_var_t. */ -static DECLARE_BITMAP(tick_broadcast_oneshot_mask, NR_CPUS); +static cpumask_var_t tick_broadcast_oneshot_mask; +static cpumask_var_t tick_broadcast_pending_mask; +static cpumask_var_t tick_broadcast_force_mask; /* * Exposed for debugging: see timer_list.c */ struct cpumask *tick_get_broadcast_oneshot_mask(void) { - return to_cpumask(tick_broadcast_oneshot_mask); + return tick_broadcast_oneshot_mask; } -static int tick_broadcast_set_event(ktime_t expires, int force) +/* + * Called before going idle with interrupts disabled. Checks whether a + * broadcast event from the other core is about to happen. We detected + * that in tick_broadcast_oneshot_control(). The callsite can use this + * to avoid a deep idle transition as we are about to get the + * broadcast IPI right away. + */ +int tick_check_broadcast_expired(void) { - struct clock_event_device *bc = tick_broadcast_device.evtdev; + return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); +} + +/* + * Set broadcast interrupt affinity + */ +static void tick_broadcast_set_affinity(struct clock_event_device *bc, + const struct cpumask *cpumask) +{ + if (!(bc->features & CLOCK_EVT_FEAT_DYNIRQ)) + return; + + if (cpumask_equal(bc->cpumask, cpumask)) + return; + + bc->cpumask = cpumask; + irq_set_affinity(bc->irq, bc->cpumask); +} + +static int tick_broadcast_set_event(struct clock_event_device *bc, int cpu, + ktime_t expires, int force) +{ + int ret; if (bc->mode != CLOCK_EVT_MODE_ONESHOT) clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT); - return clockevents_program_event(bc, expires, force); + ret = clockevents_program_event(bc, expires, force); + if (!ret) + tick_broadcast_set_affinity(bc, cpumask_of(cpu)); + return ret; } int tick_resume_broadcast_oneshot(struct clock_event_device *bc) @@ -392,7 +472,7 @@ int tick_resume_broadcast_oneshot(struct clock_event_device *bc) */ void tick_check_oneshot_broadcast(int cpu) { - if (cpumask_test_cpu(cpu, to_cpumask(tick_broadcast_oneshot_mask))) { + if (cpumask_test_cpu(cpu, tick_broadcast_oneshot_mask)) { struct tick_device *td = &per_cpu(tick_cpu_device, cpu); clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_ONESHOT); @@ -406,27 +486,39 @@ static void tick_handle_oneshot_broadcast(struct clock_event_device *dev) { struct tick_device *td; ktime_t now, next_event; - int cpu; + int cpu, next_cpu = 0; raw_spin_lock(&tick_broadcast_lock); again: dev->next_event.tv64 = KTIME_MAX; next_event.tv64 = KTIME_MAX; - cpumask_clear(to_cpumask(tmpmask)); + cpumask_clear(tmpmask); now = ktime_get(); /* Find all expired events */ - for_each_cpu(cpu, tick_get_broadcast_oneshot_mask()) { + for_each_cpu(cpu, tick_broadcast_oneshot_mask) { td = &per_cpu(tick_cpu_device, cpu); - if (td->evtdev->next_event.tv64 <= now.tv64) - cpumask_set_cpu(cpu, to_cpumask(tmpmask)); - else if (td->evtdev->next_event.tv64 < next_event.tv64) + if (td->evtdev->next_event.tv64 <= now.tv64) { + cpumask_set_cpu(cpu, tmpmask); + /* + * Mark the remote cpu in the pending mask, so + * it can avoid reprogramming the cpu local + * timer in tick_broadcast_oneshot_control(). + */ + cpumask_set_cpu(cpu, tick_broadcast_pending_mask); + } else if (td->evtdev->next_event.tv64 < next_event.tv64) { next_event.tv64 = td->evtdev->next_event.tv64; + next_cpu = cpu; + } } + /* Take care of enforced broadcast requests */ + cpumask_or(tmpmask, tmpmask, tick_broadcast_force_mask); + cpumask_clear(tick_broadcast_force_mask); + /* * Wakeup the cpus which have an expired event. */ - tick_do_broadcast(to_cpumask(tmpmask)); + tick_do_broadcast(tmpmask); /* * Two reasons for reprogram: @@ -443,7 +535,7 @@ again: * Rearm the broadcast device. If event expired, * repeat the above */ - if (tick_broadcast_set_event(next_event, 0)) + if (tick_broadcast_set_event(dev, next_cpu, next_event, 0)) goto again; } raw_spin_unlock(&tick_broadcast_lock); @@ -458,6 +550,7 @@ void tick_broadcast_oneshot_control(unsigned long reason) struct clock_event_device *bc, *dev; struct tick_device *td; unsigned long flags; + ktime_t now; int cpu; /* @@ -482,21 +575,84 @@ void tick_broadcast_oneshot_control(unsigned long reason) raw_spin_lock_irqsave(&tick_broadcast_lock, flags); if (reason == CLOCK_EVT_NOTIFY_BROADCAST_ENTER) { - if (!cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) { - cpumask_set_cpu(cpu, tick_get_broadcast_oneshot_mask()); + WARN_ON_ONCE(cpumask_test_cpu(cpu, tick_broadcast_pending_mask)); + if (!cpumask_test_and_set_cpu(cpu, tick_broadcast_oneshot_mask)) { clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN); - if (dev->next_event.tv64 < bc->next_event.tv64) - tick_broadcast_set_event(dev->next_event, 1); + /* + * We only reprogram the broadcast timer if we + * did not mark ourself in the force mask and + * if the cpu local event is earlier than the + * broadcast event. If the current CPU is in + * the force mask, then we are going to be + * woken by the IPI right away. + */ + if (!cpumask_test_cpu(cpu, tick_broadcast_force_mask) && + dev->next_event.tv64 < bc->next_event.tv64) + tick_broadcast_set_event(bc, cpu, dev->next_event, 1); } } else { - if (cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) { - cpumask_clear_cpu(cpu, - tick_get_broadcast_oneshot_mask()); + if (cpumask_test_and_clear_cpu(cpu, tick_broadcast_oneshot_mask)) { clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT); - if (dev->next_event.tv64 != KTIME_MAX) - tick_program_event(dev->next_event, 1); + if (dev->next_event.tv64 == KTIME_MAX) + goto out; + /* + * The cpu which was handling the broadcast + * timer marked this cpu in the broadcast + * pending mask and fired the broadcast + * IPI. So we are going to handle the expired + * event anyway via the broadcast IPI + * handler. No need to reprogram the timer + * with an already expired event. + */ + if (cpumask_test_and_clear_cpu(cpu, + tick_broadcast_pending_mask)) + goto out; + + /* + * If the pending bit is not set, then we are + * either the CPU handling the broadcast + * interrupt or we got woken by something else. + * + * We are not longer in the broadcast mask, so + * if the cpu local expiry time is already + * reached, we would reprogram the cpu local + * timer with an already expired event. + * + * This can lead to a ping-pong when we return + * to idle and therefor rearm the broadcast + * timer before the cpu local timer was able + * to fire. This happens because the forced + * reprogramming makes sure that the event + * will happen in the future and depending on + * the min_delta setting this might be far + * enough out that the ping-pong starts. + * + * If the cpu local next_event has expired + * then we know that the broadcast timer + * next_event has expired as well and + * broadcast is about to be handled. So we + * avoid reprogramming and enforce that the + * broadcast handler, which did not run yet, + * will invoke the cpu local handler. + * + * We cannot call the handler directly from + * here, because we might be in a NOHZ phase + * and we did not go through the irq_enter() + * nohz fixups. + */ + now = ktime_get(); + if (dev->next_event.tv64 <= now.tv64) { + cpumask_set_cpu(cpu, tick_broadcast_force_mask); + goto out; + } + /* + * We got woken by something else. Reprogram + * the cpu local timer device. + */ + tick_program_event(dev->next_event, 1); } } +out: raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); } @@ -507,7 +663,7 @@ void tick_broadcast_oneshot_control(unsigned long reason) */ static void tick_broadcast_clear_oneshot(int cpu) { - cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask()); + cpumask_clear_cpu(cpu, tick_broadcast_oneshot_mask); } static void tick_broadcast_init_next_event(struct cpumask *mask, @@ -537,7 +693,8 @@ void tick_broadcast_setup_oneshot(struct clock_event_device *bc) bc->event_handler = tick_handle_oneshot_broadcast; /* Take the do_timer update */ - tick_do_timer_cpu = cpu; + if (!tick_nohz_full_cpu(cpu)) + tick_do_timer_cpu = cpu; /* * We must be careful here. There might be other CPUs @@ -545,17 +702,16 @@ void tick_broadcast_setup_oneshot(struct clock_event_device *bc) * oneshot_mask bits for those and program the * broadcast device to fire. */ - cpumask_copy(to_cpumask(tmpmask), tick_get_broadcast_mask()); - cpumask_clear_cpu(cpu, to_cpumask(tmpmask)); - cpumask_or(tick_get_broadcast_oneshot_mask(), - tick_get_broadcast_oneshot_mask(), - to_cpumask(tmpmask)); + cpumask_copy(tmpmask, tick_broadcast_mask); + cpumask_clear_cpu(cpu, tmpmask); + cpumask_or(tick_broadcast_oneshot_mask, + tick_broadcast_oneshot_mask, tmpmask); - if (was_periodic && !cpumask_empty(to_cpumask(tmpmask))) { + if (was_periodic && !cpumask_empty(tmpmask)) { clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT); - tick_broadcast_init_next_event(to_cpumask(tmpmask), + tick_broadcast_init_next_event(tmpmask, tick_next_period); - tick_broadcast_set_event(tick_next_period, 1); + tick_broadcast_set_event(bc, cpu, tick_next_period, 1); } else bc->next_event.tv64 = KTIME_MAX; } else { @@ -603,7 +759,7 @@ void tick_shutdown_broadcast_oneshot(unsigned int *cpup) * Clear the broadcast mask flag for the dead cpu, but do not * stop the broadcast device! */ - cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask()); + cpumask_clear_cpu(cpu, tick_broadcast_oneshot_mask); raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); } @@ -627,3 +783,14 @@ bool tick_broadcast_oneshot_available(void) } #endif + +void __init tick_broadcast_init(void) +{ + alloc_cpumask_var(&tick_broadcast_mask, GFP_NOWAIT); + alloc_cpumask_var(&tmpmask, GFP_NOWAIT); +#ifdef CONFIG_TICK_ONESHOT + alloc_cpumask_var(&tick_broadcast_oneshot_mask, GFP_NOWAIT); + alloc_cpumask_var(&tick_broadcast_pending_mask, GFP_NOWAIT); + alloc_cpumask_var(&tick_broadcast_force_mask, GFP_NOWAIT); +#endif +} diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index b1600a6973f4..5d3fb100bc06 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -163,7 +163,10 @@ static void tick_setup_device(struct tick_device *td, * this cpu: */ if (tick_do_timer_cpu == TICK_DO_TIMER_BOOT) { - tick_do_timer_cpu = cpu; + if (!tick_nohz_full_cpu(cpu)) + tick_do_timer_cpu = cpu; + else + tick_do_timer_cpu = TICK_DO_TIMER_NONE; tick_next_period = ktime_get(); tick_period = ktime_set(0, NSEC_PER_SEC / HZ); } @@ -323,6 +326,7 @@ static void tick_shutdown(unsigned int *cpup) */ dev->mode = CLOCK_EVT_MODE_UNUSED; clockevents_exchange_device(dev, NULL); + dev->event_handler = clockevents_handle_noop; td->evtdev = NULL; } raw_spin_unlock_irqrestore(&tick_device_lock, flags); @@ -416,4 +420,5 @@ static struct notifier_block tick_notifier = { void __init tick_init(void) { clockevents_register_notifier(&tick_notifier); + tick_broadcast_init(); } diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index cf3e59ed6dc0..f0299eae4602 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -4,6 +4,8 @@ #include <linux/hrtimer.h> #include <linux/tick.h> +extern seqlock_t jiffies_lock; + #ifdef CONFIG_GENERIC_CLOCKEVENTS_BUILD #define TICK_DO_TIMER_NONE -1 @@ -94,7 +96,7 @@ extern void tick_broadcast_on_off(unsigned long reason, int *oncpu); extern void tick_shutdown_broadcast(unsigned int *cpup); extern void tick_suspend_broadcast(void); extern int tick_resume_broadcast(void); - +extern void tick_broadcast_init(void); extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast); @@ -119,6 +121,7 @@ static inline void tick_broadcast_on_off(unsigned long reason, int *oncpu) { } static inline void tick_shutdown_broadcast(unsigned int *cpup) { } static inline void tick_suspend_broadcast(void) { } static inline int tick_resume_broadcast(void) { return 0; } +static inline void tick_broadcast_init(void) { } /* * Set the periodic handler in non broadcast mode diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index d58e552d9fd1..bc67d4245e1d 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -20,15 +20,20 @@ #include <linux/profile.h> #include <linux/sched.h> #include <linux/module.h> +#include <linux/irq_work.h> +#include <linux/posix-timers.h> +#include <linux/perf_event.h> #include <asm/irq_regs.h> #include "tick-internal.h" +#include <trace/events/timer.h> + /* * Per cpu nohz control structure */ -static DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched); +DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched); /* * The time, when the last jiffy update happened. Protected by jiffies_lock. @@ -103,7 +108,7 @@ static void tick_sched_do_timer(ktime_t now) { int cpu = smp_processor_id(); -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON /* * Check if the do_timer duty was dropped. We don't care about * concurrency: This happens only when the cpu in charge went @@ -111,7 +116,8 @@ static void tick_sched_do_timer(ktime_t now) * this duty, then the jiffies update is still serialized by * jiffies_lock. */ - if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE)) + if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE) + && !tick_nohz_full_cpu(cpu)) tick_do_timer_cpu = cpu; #endif @@ -122,7 +128,7 @@ static void tick_sched_do_timer(ktime_t now) static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs) { -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON /* * When we are idle and the tick is stopped, we have to touch * the watchdog as we might not schedule for a really long @@ -141,10 +147,226 @@ static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs) profile_tick(CPU_PROFILING); } +#ifdef CONFIG_NO_HZ_FULL +static cpumask_var_t nohz_full_mask; +bool have_nohz_full_mask; + +static bool can_stop_full_tick(void) +{ + WARN_ON_ONCE(!irqs_disabled()); + + if (!sched_can_stop_tick()) { + trace_tick_stop(0, "more than 1 task in runqueue\n"); + return false; + } + + if (!posix_cpu_timers_can_stop_tick(current)) { + trace_tick_stop(0, "posix timers running\n"); + return false; + } + + if (!perf_event_can_stop_tick()) { + trace_tick_stop(0, "perf events running\n"); + return false; + } + + /* sched_clock_tick() needs us? */ +#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK + /* + * TODO: kick full dynticks CPUs when + * sched_clock_stable is set. + */ + if (!sched_clock_stable) { + trace_tick_stop(0, "unstable sched clock\n"); + return false; + } +#endif + + return true; +} + +static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now); + +/* + * Re-evaluate the need for the tick on the current CPU + * and restart it if necessary. + */ +void tick_nohz_full_check(void) +{ + struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched); + + if (tick_nohz_full_cpu(smp_processor_id())) { + if (ts->tick_stopped && !is_idle_task(current)) { + if (!can_stop_full_tick()) + tick_nohz_restart_sched_tick(ts, ktime_get()); + } + } +} + +static void nohz_full_kick_work_func(struct irq_work *work) +{ + tick_nohz_full_check(); +} + +static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = { + .func = nohz_full_kick_work_func, +}; + +/* + * Kick the current CPU if it's full dynticks in order to force it to + * re-evaluate its dependency on the tick and restart it if necessary. + */ +void tick_nohz_full_kick(void) +{ + if (tick_nohz_full_cpu(smp_processor_id())) + irq_work_queue(&__get_cpu_var(nohz_full_kick_work)); +} + +static void nohz_full_kick_ipi(void *info) +{ + tick_nohz_full_check(); +} + +/* + * Kick all full dynticks CPUs in order to force these to re-evaluate + * their dependency on the tick and restart it if necessary. + */ +void tick_nohz_full_kick_all(void) +{ + if (!have_nohz_full_mask) + return; + + preempt_disable(); + smp_call_function_many(nohz_full_mask, + nohz_full_kick_ipi, NULL, false); + preempt_enable(); +} + +/* + * Re-evaluate the need for the tick as we switch the current task. + * It might need the tick due to per task/process properties: + * perf events, posix cpu timers, ... + */ +void tick_nohz_task_switch(struct task_struct *tsk) +{ + unsigned long flags; + + local_irq_save(flags); + + if (!tick_nohz_full_cpu(smp_processor_id())) + goto out; + + if (tick_nohz_tick_stopped() && !can_stop_full_tick()) + tick_nohz_full_kick(); + +out: + local_irq_restore(flags); +} + +int tick_nohz_full_cpu(int cpu) +{ + if (!have_nohz_full_mask) + return 0; + + return cpumask_test_cpu(cpu, nohz_full_mask); +} + +/* Parse the boot-time nohz CPU list from the kernel parameters. */ +static int __init tick_nohz_full_setup(char *str) +{ + int cpu; + + alloc_bootmem_cpumask_var(&nohz_full_mask); + if (cpulist_parse(str, nohz_full_mask) < 0) { + pr_warning("NOHZ: Incorrect nohz_full cpumask\n"); + return 1; + } + + cpu = smp_processor_id(); + if (cpumask_test_cpu(cpu, nohz_full_mask)) { + pr_warning("NO_HZ: Clearing %d from nohz_full range for timekeeping\n", cpu); + cpumask_clear_cpu(cpu, nohz_full_mask); + } + have_nohz_full_mask = true; + + return 1; +} +__setup("nohz_full=", tick_nohz_full_setup); + +static int __cpuinit tick_nohz_cpu_down_callback(struct notifier_block *nfb, + unsigned long action, + void *hcpu) +{ + unsigned int cpu = (unsigned long)hcpu; + + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_DOWN_PREPARE: + /* + * If we handle the timekeeping duty for full dynticks CPUs, + * we can't safely shutdown that CPU. + */ + if (have_nohz_full_mask && tick_do_timer_cpu == cpu) + return -EINVAL; + break; + } + return NOTIFY_OK; +} + +/* + * Worst case string length in chunks of CPU range seems 2 steps + * separations: 0,2,4,6,... + * This is NR_CPUS + sizeof('\0') + */ +static char __initdata nohz_full_buf[NR_CPUS + 1]; + +static int tick_nohz_init_all(void) +{ + int err = -1; + +#ifdef CONFIG_NO_HZ_FULL_ALL + if (!alloc_cpumask_var(&nohz_full_mask, GFP_KERNEL)) { + pr_err("NO_HZ: Can't allocate full dynticks cpumask\n"); + return err; + } + err = 0; + cpumask_setall(nohz_full_mask); + cpumask_clear_cpu(smp_processor_id(), nohz_full_mask); + have_nohz_full_mask = true; +#endif + return err; +} + +void __init tick_nohz_init(void) +{ + int cpu; + + if (!have_nohz_full_mask) { + if (tick_nohz_init_all() < 0) + return; + } + + cpu_notifier(tick_nohz_cpu_down_callback, 0); + + /* Make sure full dynticks CPU are also RCU nocbs */ + for_each_cpu(cpu, nohz_full_mask) { + if (!rcu_is_nocb_cpu(cpu)) { + pr_warning("NO_HZ: CPU %d is not RCU nocb: " + "cleared from nohz_full range", cpu); + cpumask_clear_cpu(cpu, nohz_full_mask); + } + } + + cpulist_scnprintf(nohz_full_buf, sizeof(nohz_full_buf), nohz_full_mask); + pr_info("NO_HZ: Full dynticks CPUs: %s.\n", nohz_full_buf); +} +#else +#define have_nohz_full_mask (0) +#endif + /* * NOHZ - aka dynamic tick functionality */ -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON /* * NO HZ enabled ? */ @@ -331,8 +553,8 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, time_delta = timekeeping_max_deferment(); } while (read_seqretry(&jiffies_lock, seq)); - if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || printk_needs_cpu(cpu) || - arch_needs_cpu(cpu)) { + if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || + arch_needs_cpu(cpu) || irq_work_needs_cpu()) { next_jiffies = last_jiffies + 1; delta_jiffies = 1; } else { @@ -344,11 +566,12 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, delta_jiffies = rcu_delta_jiffies; } } + /* - * Do not stop the tick, if we are only one off - * or if the cpu is required for rcu + * Do not stop the tick, if we are only one off (or less) + * or if the cpu is required for RCU: */ - if (!ts->tick_stopped && delta_jiffies == 1) + if (!ts->tick_stopped && delta_jiffies <= 1) goto out; /* Schedule the tick, if we are at least one jiffie off */ @@ -377,6 +600,13 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, time_delta = KTIME_MAX; } +#ifdef CONFIG_NO_HZ_FULL + if (!ts->inidle) { + time_delta = min(time_delta, + scheduler_tick_max_deferment()); + } +#endif + /* * calculate the expiry time for the next timer wheel * timer. delta_jiffies >= NEXT_TIMER_MAX_DELTA signals @@ -420,6 +650,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, ts->last_tick = hrtimer_get_expires(&ts->sched_timer); ts->tick_stopped = 1; + trace_tick_stop(1, " "); } /* @@ -456,6 +687,24 @@ out: return ret; } +static void tick_nohz_full_stop_tick(struct tick_sched *ts) +{ +#ifdef CONFIG_NO_HZ_FULL + int cpu = smp_processor_id(); + + if (!tick_nohz_full_cpu(cpu) || is_idle_task(current)) + return; + + if (!ts->tick_stopped && ts->nohz_mode == NOHZ_MODE_INACTIVE) + return; + + if (!can_stop_full_tick()) + return; + + tick_nohz_stop_sched_tick(ts, ktime_get(), cpu); +#endif +} + static bool can_stop_idle_tick(int cpu, struct tick_sched *ts) { /* @@ -481,13 +730,28 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts) if (ratelimit < 10 && (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) { - printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n", - (unsigned int) local_softirq_pending()); + pr_warn("NOHZ: local_softirq_pending %02x\n", + (unsigned int) local_softirq_pending()); ratelimit++; } return false; } + if (have_nohz_full_mask) { + /* + * Keep the tick alive to guarantee timekeeping progression + * if there are full dynticks CPUs around + */ + if (tick_do_timer_cpu == cpu) + return false; + /* + * Boot safety: make sure the timekeeping duty has been + * assigned before entering dyntick-idle mode, + */ + if (tick_do_timer_cpu == TICK_DO_TIMER_NONE) + return false; + } + return true; } @@ -553,6 +817,7 @@ void tick_nohz_idle_enter(void) local_irq_enable(); } +EXPORT_SYMBOL_GPL(tick_nohz_idle_enter); /** * tick_nohz_irq_exit - update next tick event from interrupt exit @@ -566,12 +831,13 @@ void tick_nohz_irq_exit(void) { struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched); - if (!ts->inidle) - return; - - /* Cancel the timer because CPU already waken up from the C-states*/ - menu_hrtimer_cancel(); - __tick_nohz_idle_enter(ts); + if (ts->inidle) { + /* Cancel the timer because CPU already waken up from the C-states*/ + menu_hrtimer_cancel(); + __tick_nohz_idle_enter(ts); + } else { + tick_nohz_full_stop_tick(ts); + } } /** @@ -631,8 +897,11 @@ static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now) static void tick_nohz_account_idle_ticks(struct tick_sched *ts) { -#ifndef CONFIG_VIRT_CPU_ACCOUNTING +#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE unsigned long ticks; + + if (vtime_accounting_enabled()) + return; /* * We stopped the tick in idle. Update process times would miss the * time we slept as update_process_times does only a 1 tick @@ -681,6 +950,7 @@ void tick_nohz_idle_exit(void) local_irq_enable(); } +EXPORT_SYMBOL_GPL(tick_nohz_idle_exit); static int tick_nohz_reprogram(struct tick_sched *ts, ktime_t now) { @@ -796,7 +1066,7 @@ static inline void tick_check_nohz(int cpu) static inline void tick_nohz_switch_to_nohz(void) { } static inline void tick_check_nohz(int cpu) { } -#endif /* NO_HZ */ +#endif /* CONFIG_NO_HZ_COMMON */ /* * Called from irq_enter to notify about the possible interruption of idle() @@ -881,14 +1151,14 @@ void tick_setup_sched_timer(void) now = ktime_get(); } -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON if (tick_nohz_enabled) ts->nohz_mode = NOHZ_MODE_HIGHRES; #endif } #endif /* HIGH_RES_TIMERS */ -#if defined CONFIG_NO_HZ || defined CONFIG_HIGH_RES_TIMERS +#if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS void tick_cancel_sched_timer(int cpu) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index cbc6acb0db3f..98cd470bbe49 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -23,12 +23,20 @@ #include <linux/stop_machine.h> #include <linux/pvclock_gtod.h> +#include "tick-internal.h" +#include "ntp_internal.h" static struct timekeeper timekeeper; +static DEFINE_RAW_SPINLOCK(timekeeper_lock); +static seqcount_t timekeeper_seq; +static struct timekeeper shadow_timekeeper; /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; +/* Flag for if there is a persistent clock on this platform */ +bool __read_mostly persistent_clock_exist = false; + static inline void tk_normalize_xtime(struct timekeeper *tk) { while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) { @@ -64,6 +72,7 @@ static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm) tk->wall_to_monotonic = wtm; set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec); tk->offs_real = timespec_to_ktime(tmp); + tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tk->tai_offset, 0)); } static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t) @@ -93,7 +102,7 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) old_clock = tk->clock; tk->clock = clock; - clock->cycle_last = clock->read(clock); + tk->cycle_last = clock->cycle_last = clock->read(clock); /* Do the ns -> cycle conversion first, using original mult */ tmp = NTP_INTERVAL_LENGTH; @@ -135,6 +144,20 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) } /* Timekeeper helper functions. */ + +#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET +u32 (*arch_gettimeoffset)(void); + +u32 get_arch_timeoffset(void) +{ + if (likely(arch_gettimeoffset)) + return arch_gettimeoffset(); + return 0; +} +#else +static inline u32 get_arch_timeoffset(void) { return 0; } +#endif + static inline s64 timekeeping_get_ns(struct timekeeper *tk) { cycle_t cycle_now, cycle_delta; @@ -151,8 +174,8 @@ static inline s64 timekeeping_get_ns(struct timekeeper *tk) nsec = cycle_delta * tk->mult + tk->xtime_nsec; nsec >>= tk->shift; - /* If arch requires, add in gettimeoffset() */ - return nsec + arch_gettimeoffset(); + /* If arch requires, add in get_arch_timeoffset() */ + return nsec + get_arch_timeoffset(); } static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk) @@ -171,8 +194,8 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk) /* convert delta to nanoseconds. */ nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); - /* If arch requires, add in gettimeoffset() */ - return nsec + arch_gettimeoffset(); + /* If arch requires, add in get_arch_timeoffset() */ + return nsec + get_arch_timeoffset(); } static RAW_NOTIFIER_HEAD(pvclock_gtod_chain); @@ -184,8 +207,6 @@ static void update_pvclock_gtod(struct timekeeper *tk) /** * pvclock_gtod_register_notifier - register a pvclock timedata update listener - * - * Must hold write on timekeeper.lock */ int pvclock_gtod_register_notifier(struct notifier_block *nb) { @@ -193,11 +214,10 @@ int pvclock_gtod_register_notifier(struct notifier_block *nb) unsigned long flags; int ret; - write_seqlock_irqsave(&tk->lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb); - /* update timekeeping data */ update_pvclock_gtod(tk); - write_sequnlock_irqrestore(&tk->lock, flags); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); return ret; } @@ -206,25 +226,22 @@ EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier); /** * pvclock_gtod_unregister_notifier - unregister a pvclock * timedata update listener - * - * Must hold write on timekeeper.lock */ int pvclock_gtod_unregister_notifier(struct notifier_block *nb) { - struct timekeeper *tk = &timekeeper; unsigned long flags; int ret; - write_seqlock_irqsave(&tk->lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb); - write_sequnlock_irqrestore(&tk->lock, flags); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); return ret; } EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); -/* must hold write on timekeeper.lock */ -static void timekeeping_update(struct timekeeper *tk, bool clearntp) +/* must hold timekeeper_lock */ +static void timekeeping_update(struct timekeeper *tk, bool clearntp, bool mirror) { if (clearntp) { tk->ntp_error = 0; @@ -232,6 +249,9 @@ static void timekeeping_update(struct timekeeper *tk, bool clearntp) } update_vsyscall(tk); update_pvclock_gtod(tk); + + if (mirror) + memcpy(&shadow_timekeeper, &timekeeper, sizeof(timekeeper)); } /** @@ -250,12 +270,12 @@ static void timekeeping_forward_now(struct timekeeper *tk) clock = tk->clock; cycle_now = clock->read(clock); cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - clock->cycle_last = cycle_now; + tk->cycle_last = clock->cycle_last = cycle_now; tk->xtime_nsec += cycle_delta * tk->mult; - /* If arch requires, add in gettimeoffset() */ - tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift; + /* If arch requires, add in get_arch_timeoffset() */ + tk->xtime_nsec += (u64)get_arch_timeoffset() << tk->shift; tk_normalize_xtime(tk); @@ -264,29 +284,48 @@ static void timekeeping_forward_now(struct timekeeper *tk) } /** - * getnstimeofday - Returns the time of day in a timespec + * __getnstimeofday - Returns the time of day in a timespec. * @ts: pointer to the timespec to be set * - * Returns the time of day in a timespec. + * Updates the time of day in the timespec. + * Returns 0 on success, or -ve when suspended (timespec will be undefined). */ -void getnstimeofday(struct timespec *ts) +int __getnstimeofday(struct timespec *ts) { struct timekeeper *tk = &timekeeper; unsigned long seq; s64 nsecs = 0; - WARN_ON(timekeeping_suspended); - do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); ts->tv_sec = tk->xtime_sec; nsecs = timekeeping_get_ns(tk); - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); ts->tv_nsec = 0; timespec_add_ns(ts, nsecs); + + /* + * Do not bail out early, in case there were callers still using + * the value, even in the face of the WARN_ON. + */ + if (unlikely(timekeeping_suspended)) + return -EAGAIN; + return 0; +} +EXPORT_SYMBOL(__getnstimeofday); + +/** + * getnstimeofday - Returns the time of day in a timespec. + * @ts: pointer to the timespec to be set + * + * Returns the time of day in a timespec (WARN if suspended). + */ +void getnstimeofday(struct timespec *ts) +{ + WARN_ON(__getnstimeofday(ts)); } EXPORT_SYMBOL(getnstimeofday); @@ -299,11 +338,11 @@ ktime_t ktime_get(void) WARN_ON(timekeeping_suspended); do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec; - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); /* * Use ktime_set/ktime_add_ns to create a proper ktime on * 32-bit architectures without CONFIG_KTIME_SCALAR. @@ -330,12 +369,12 @@ void ktime_get_ts(struct timespec *ts) WARN_ON(timekeeping_suspended); do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); ts->tv_sec = tk->xtime_sec; nsec = timekeeping_get_ns(tk); tomono = tk->wall_to_monotonic; - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); ts->tv_sec += tomono.tv_sec; ts->tv_nsec = 0; @@ -343,6 +382,50 @@ void ktime_get_ts(struct timespec *ts) } EXPORT_SYMBOL_GPL(ktime_get_ts); + +/** + * timekeeping_clocktai - Returns the TAI time of day in a timespec + * @ts: pointer to the timespec to be set + * + * Returns the time of day in a timespec. + */ +void timekeeping_clocktai(struct timespec *ts) +{ + struct timekeeper *tk = &timekeeper; + unsigned long seq; + u64 nsecs; + + WARN_ON(timekeeping_suspended); + + do { + seq = read_seqcount_begin(&timekeeper_seq); + + ts->tv_sec = tk->xtime_sec + tk->tai_offset; + nsecs = timekeeping_get_ns(tk); + + } while (read_seqcount_retry(&timekeeper_seq, seq)); + + ts->tv_nsec = 0; + timespec_add_ns(ts, nsecs); + +} +EXPORT_SYMBOL(timekeeping_clocktai); + + +/** + * ktime_get_clocktai - Returns the TAI time of day in a ktime + * + * Returns the time of day in a ktime. + */ +ktime_t ktime_get_clocktai(void) +{ + struct timespec ts; + + timekeeping_clocktai(&ts); + return timespec_to_ktime(ts); +} +EXPORT_SYMBOL(ktime_get_clocktai); + #ifdef CONFIG_NTP_PPS /** @@ -363,7 +446,7 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) WARN_ON_ONCE(timekeeping_suspended); do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); *ts_raw = tk->raw_time; ts_real->tv_sec = tk->xtime_sec; @@ -372,7 +455,7 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) nsecs_raw = timekeeping_get_ns_raw(tk); nsecs_real = timekeeping_get_ns(tk); - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); timespec_add_ns(ts_raw, nsecs_raw); timespec_add_ns(ts_real, nsecs_real); @@ -412,7 +495,8 @@ int do_settimeofday(const struct timespec *tv) if (!timespec_valid_strict(tv)) return -EINVAL; - write_seqlock_irqsave(&tk->lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); timekeeping_forward_now(tk); @@ -424,9 +508,10 @@ int do_settimeofday(const struct timespec *tv) tk_set_xtime(tk, tv); - timekeeping_update(tk, true); + timekeeping_update(tk, true, true); - write_sequnlock_irqrestore(&tk->lock, flags); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); /* signal hrtimers about time change */ clock_was_set(); @@ -451,7 +536,8 @@ int timekeeping_inject_offset(struct timespec *ts) if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) return -EINVAL; - write_seqlock_irqsave(&tk->lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); timekeeping_forward_now(tk); @@ -466,9 +552,10 @@ int timekeeping_inject_offset(struct timespec *ts) tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts)); error: /* even if we error out, we forwarded the time, so call update */ - timekeeping_update(tk, true); + timekeeping_update(tk, true, true); - write_sequnlock_irqrestore(&tk->lock, flags); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); /* signal hrtimers about time change */ clock_was_set(); @@ -477,6 +564,52 @@ error: /* even if we error out, we forwarded the time, so call update */ } EXPORT_SYMBOL(timekeeping_inject_offset); + +/** + * timekeeping_get_tai_offset - Returns current TAI offset from UTC + * + */ +s32 timekeeping_get_tai_offset(void) +{ + struct timekeeper *tk = &timekeeper; + unsigned int seq; + s32 ret; + + do { + seq = read_seqcount_begin(&timekeeper_seq); + ret = tk->tai_offset; + } while (read_seqcount_retry(&timekeeper_seq, seq)); + + return ret; +} + +/** + * __timekeeping_set_tai_offset - Lock free worker function + * + */ +static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset) +{ + tk->tai_offset = tai_offset; + tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tai_offset, 0)); +} + +/** + * timekeeping_set_tai_offset - Sets the current TAI offset from UTC + * + */ +void timekeeping_set_tai_offset(s32 tai_offset) +{ + struct timekeeper *tk = &timekeeper; + unsigned long flags; + + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); + __timekeeping_set_tai_offset(tk, tai_offset); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + clock_was_set(); +} + /** * change_clocksource - Swaps clocksources if a new one is available * @@ -490,7 +623,8 @@ static int change_clocksource(void *data) new = (struct clocksource *) data; - write_seqlock_irqsave(&tk->lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); timekeeping_forward_now(tk); if (!new->enable || new->enable(new) == 0) { @@ -499,9 +633,10 @@ static int change_clocksource(void *data) if (old->disable) old->disable(old); } - timekeeping_update(tk, true); + timekeeping_update(tk, true, true); - write_sequnlock_irqrestore(&tk->lock, flags); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); return 0; } @@ -551,11 +686,11 @@ void getrawmonotonic(struct timespec *ts) s64 nsecs; do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); nsecs = timekeeping_get_ns_raw(tk); *ts = tk->raw_time; - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); timespec_add_ns(ts, nsecs); } @@ -571,11 +706,11 @@ int timekeeping_valid_for_hres(void) int ret; do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); return ret; } @@ -590,11 +725,11 @@ u64 timekeeping_max_deferment(void) u64 ret; do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); ret = tk->clock->max_idle_ns; - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); return ret; } @@ -640,12 +775,14 @@ void __init timekeeping_init(void) struct timespec now, boot, tmp; read_persistent_clock(&now); + if (!timespec_valid_strict(&now)) { pr_warn("WARNING: Persistent clock returned invalid value!\n" " Check your CMOS/BIOS settings.\n"); now.tv_sec = 0; now.tv_nsec = 0; - } + } else if (now.tv_sec || now.tv_nsec) + persistent_clock_exist = true; read_boot_clock(&boot); if (!timespec_valid_strict(&boot)) { @@ -655,11 +792,10 @@ void __init timekeeping_init(void) boot.tv_nsec = 0; } - seqlock_init(&tk->lock); - + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); ntp_init(); - write_seqlock_irqsave(&tk->lock, flags); clock = clocksource_default_clock(); if (clock->enable) clock->enable(clock); @@ -678,7 +814,10 @@ void __init timekeeping_init(void) tmp.tv_nsec = 0; tk_set_sleep_time(tk, tmp); - write_sequnlock_irqrestore(&tk->lock, flags); + memcpy(&shadow_timekeeper, &timekeeper, sizeof(timekeeper)); + + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); } /* time in seconds when suspend began */ @@ -718,22 +857,25 @@ void timekeeping_inject_sleeptime(struct timespec *delta) { struct timekeeper *tk = &timekeeper; unsigned long flags; - struct timespec ts; - /* Make sure we don't set the clock twice */ - read_persistent_clock(&ts); - if (!(ts.tv_sec == 0 && ts.tv_nsec == 0)) + /* + * Make sure we don't set the clock twice, as timekeeping_resume() + * already did it + */ + if (has_persistent_clock()) return; - write_seqlock_irqsave(&tk->lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); timekeeping_forward_now(tk); __timekeeping_inject_sleeptime(tk, delta); - timekeeping_update(tk, true); + timekeeping_update(tk, true, true); - write_sequnlock_irqrestore(&tk->lock, flags); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); /* signal hrtimers about time change */ clock_was_set(); @@ -749,26 +891,72 @@ void timekeeping_inject_sleeptime(struct timespec *delta) static void timekeeping_resume(void) { struct timekeeper *tk = &timekeeper; + struct clocksource *clock = tk->clock; unsigned long flags; - struct timespec ts; + struct timespec ts_new, ts_delta; + cycle_t cycle_now, cycle_delta; + bool suspendtime_found = false; - read_persistent_clock(&ts); + read_persistent_clock(&ts_new); clockevents_resume(); clocksource_resume(); - write_seqlock_irqsave(&tk->lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); - if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { - ts = timespec_sub(ts, timekeeping_suspend_time); - __timekeeping_inject_sleeptime(tk, &ts); + /* + * After system resumes, we need to calculate the suspended time and + * compensate it for the OS time. There are 3 sources that could be + * used: Nonstop clocksource during suspend, persistent clock and rtc + * device. + * + * One specific platform may have 1 or 2 or all of them, and the + * preference will be: + * suspend-nonstop clocksource -> persistent clock -> rtc + * The less preferred source will only be tried if there is no better + * usable source. The rtc part is handled separately in rtc core code. + */ + cycle_now = clock->read(clock); + if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) && + cycle_now > clock->cycle_last) { + u64 num, max = ULLONG_MAX; + u32 mult = clock->mult; + u32 shift = clock->shift; + s64 nsec = 0; + + cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; + + /* + * "cycle_delta * mutl" may cause 64 bits overflow, if the + * suspended time is too long. In that case we need do the + * 64 bits math carefully + */ + do_div(max, mult); + if (cycle_delta > max) { + num = div64_u64(cycle_delta, max); + nsec = (((u64) max * mult) >> shift) * num; + cycle_delta -= num * max; + } + nsec += ((u64) cycle_delta * mult) >> shift; + + ts_delta = ns_to_timespec(nsec); + suspendtime_found = true; + } else if (timespec_compare(&ts_new, &timekeeping_suspend_time) > 0) { + ts_delta = timespec_sub(ts_new, timekeeping_suspend_time); + suspendtime_found = true; } - /* re-base the last cycle value */ - tk->clock->cycle_last = tk->clock->read(tk->clock); + + if (suspendtime_found) + __timekeeping_inject_sleeptime(tk, &ts_delta); + + /* Re-base the last cycle value */ + tk->cycle_last = clock->cycle_last = cycle_now; tk->ntp_error = 0; timekeeping_suspended = 0; - timekeeping_update(tk, false); - write_sequnlock_irqrestore(&tk->lock, flags); + timekeeping_update(tk, false, true); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); touch_softlockup_watchdog(); @@ -787,7 +975,8 @@ static int timekeeping_suspend(void) read_persistent_clock(&timekeeping_suspend_time); - write_seqlock_irqsave(&tk->lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); timekeeping_forward_now(tk); timekeeping_suspended = 1; @@ -810,7 +999,8 @@ static int timekeeping_suspend(void) timekeeping_suspend_time = timespec_add(timekeeping_suspend_time, delta_delta); } - write_sequnlock_irqrestore(&tk->lock, flags); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); clocksource_suspend(); @@ -1060,6 +1250,8 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk) tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts)); + __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); + clock_was_set_delayed(); } } @@ -1077,15 +1269,16 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk) static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, u32 shift) { + cycle_t interval = tk->cycle_interval << shift; u64 raw_nsecs; /* If the offset is smaller then a shifted interval, do nothing */ - if (offset < tk->cycle_interval<<shift) + if (offset < interval) return offset; /* Accumulate one shifted interval */ - offset -= tk->cycle_interval << shift; - tk->clock->cycle_last += tk->cycle_interval << shift; + offset -= interval; + tk->cycle_last += interval; tk->xtime_nsec += tk->xtime_interval << shift; accumulate_nsecs_to_secs(tk); @@ -1142,27 +1335,28 @@ static inline void old_vsyscall_fixup(struct timekeeper *tk) static void update_wall_time(void) { struct clocksource *clock; - struct timekeeper *tk = &timekeeper; + struct timekeeper *real_tk = &timekeeper; + struct timekeeper *tk = &shadow_timekeeper; cycle_t offset; int shift = 0, maxshift; unsigned long flags; - write_seqlock_irqsave(&tk->lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); /* Make sure we're fully resumed: */ if (unlikely(timekeeping_suspended)) goto out; - clock = tk->clock; + clock = real_tk->clock; #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET - offset = tk->cycle_interval; + offset = real_tk->cycle_interval; #else offset = (clock->read(clock) - clock->cycle_last) & clock->mask; #endif /* Check if there's really nothing to do */ - if (offset < tk->cycle_interval) + if (offset < real_tk->cycle_interval) goto out; /* @@ -1199,11 +1393,24 @@ static void update_wall_time(void) */ accumulate_nsecs_to_secs(tk); - timekeeping_update(tk, false); - + write_seqcount_begin(&timekeeper_seq); + /* Update clock->cycle_last with the new value */ + clock->cycle_last = tk->cycle_last; + /* + * Update the real timekeeper. + * + * We could avoid this memcpy by switching pointers, but that + * requires changes to all other timekeeper usage sites as + * well, i.e. move the timekeeper pointer getter into the + * spinlocked/seqcount protected sections. And we trade this + * memcpy under the timekeeper_seq against one before we start + * updating. + */ + memcpy(real_tk, tk, sizeof(*tk)); + timekeeping_update(real_tk, false, false); + write_seqcount_end(&timekeeper_seq); out: - write_sequnlock_irqrestore(&tk->lock, flags); - + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); } /** @@ -1250,13 +1457,13 @@ void get_monotonic_boottime(struct timespec *ts) WARN_ON(timekeeping_suspended); do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); ts->tv_sec = tk->xtime_sec; nsec = timekeeping_get_ns(tk); tomono = tk->wall_to_monotonic; sleep = tk->total_sleep_time; - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); ts->tv_sec += tomono.tv_sec + sleep.tv_sec; ts->tv_nsec = 0; @@ -1315,10 +1522,10 @@ struct timespec current_kernel_time(void) unsigned long seq; do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); now = tk_xtime(tk); - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); return now; } @@ -1331,11 +1538,11 @@ struct timespec get_monotonic_coarse(void) unsigned long seq; do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); now = tk_xtime(tk); mono = tk->wall_to_monotonic; - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, now.tv_nsec + mono.tv_nsec); @@ -1366,11 +1573,11 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim, unsigned long seq; do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); *xtim = tk_xtime(tk); *wtom = tk->wall_to_monotonic; *sleep = tk->total_sleep_time; - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); } #ifdef CONFIG_HIGH_RES_TIMERS @@ -1382,7 +1589,8 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim, * Returns current monotonic time and updates the offsets * Called from hrtimer_interupt() or retrigger_next_event() */ -ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot) +ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot, + ktime_t *offs_tai) { struct timekeeper *tk = &timekeeper; ktime_t now; @@ -1390,14 +1598,15 @@ ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot) u64 secs, nsecs; do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); secs = tk->xtime_sec; nsecs = timekeeping_get_ns(tk); *offs_real = tk->offs_real; *offs_boot = tk->offs_boot; - } while (read_seqretry(&tk->lock, seq)); + *offs_tai = tk->offs_tai; + } while (read_seqcount_retry(&timekeeper_seq, seq)); now = ktime_add_ns(ktime_set(secs, 0), nsecs); now = ktime_sub(now, *offs_real); @@ -1415,15 +1624,79 @@ ktime_t ktime_get_monotonic_offset(void) struct timespec wtom; do { - seq = read_seqbegin(&tk->lock); + seq = read_seqcount_begin(&timekeeper_seq); wtom = tk->wall_to_monotonic; - } while (read_seqretry(&tk->lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); return timespec_to_ktime(wtom); } EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset); /** + * do_adjtimex() - Accessor function to NTP __do_adjtimex function + */ +int do_adjtimex(struct timex *txc) +{ + struct timekeeper *tk = &timekeeper; + unsigned long flags; + struct timespec ts; + s32 orig_tai, tai; + int ret; + + /* Validate the data before disabling interrupts */ + ret = ntp_validate_timex(txc); + if (ret) + return ret; + + if (txc->modes & ADJ_SETOFFSET) { + struct timespec delta; + delta.tv_sec = txc->time.tv_sec; + delta.tv_nsec = txc->time.tv_usec; + if (!(txc->modes & ADJ_NANO)) + delta.tv_nsec *= 1000; + ret = timekeeping_inject_offset(&delta); + if (ret) + return ret; + } + + getnstimeofday(&ts); + + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); + + orig_tai = tai = tk->tai_offset; + ret = __do_adjtimex(txc, &ts, &tai); + + if (tai != orig_tai) { + __timekeeping_set_tai_offset(tk, tai); + clock_was_set_delayed(); + } + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + + return ret; +} + +#ifdef CONFIG_NTP_PPS +/** + * hardpps() - Accessor function to NTP __hardpps function + */ +void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); + + __hardpps(phase_ts, raw_ts); + + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); +} +EXPORT_SYMBOL(hardpps); +#endif + +/** * xtime_update() - advances the timekeeping infrastructure * @ticks: number of ticks, that have elapsed since the last call. * diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index af5a7e9f164b..3bdf28323012 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -20,6 +20,13 @@ #include <asm/uaccess.h> + +struct timer_list_iter { + int cpu; + bool second_pass; + u64 now; +}; + typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes); DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases); @@ -133,7 +140,6 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now) struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); int i; - SEQ_printf(m, "\n"); SEQ_printf(m, "cpu: %d\n", cpu); for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { SEQ_printf(m, " clock %d:\n", i); @@ -187,6 +193,7 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now) #undef P #undef P_ns + SEQ_printf(m, "\n"); } #ifdef CONFIG_GENERIC_CLOCKEVENTS @@ -195,7 +202,6 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) { struct clock_event_device *dev = td->evtdev; - SEQ_printf(m, "\n"); SEQ_printf(m, "Tick Device: mode: %d\n", td->mode); if (cpu < 0) SEQ_printf(m, "Broadcast device\n"); @@ -230,12 +236,11 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) print_name_offset(m, dev->event_handler); SEQ_printf(m, "\n"); SEQ_printf(m, " retries: %lu\n", dev->retries); + SEQ_printf(m, "\n"); } -static void timer_list_show_tickdevices(struct seq_file *m) +static void timer_list_show_tickdevices_header(struct seq_file *m) { - int cpu; - #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST print_tickdevice(m, tick_get_broadcast_device(), -1); SEQ_printf(m, "tick_broadcast_mask: %08lx\n", @@ -246,47 +251,104 @@ static void timer_list_show_tickdevices(struct seq_file *m) #endif SEQ_printf(m, "\n"); #endif - for_each_online_cpu(cpu) - print_tickdevice(m, tick_get_device(cpu), cpu); - SEQ_printf(m, "\n"); } -#else -static void timer_list_show_tickdevices(struct seq_file *m) { } #endif +static inline void timer_list_header(struct seq_file *m, u64 now) +{ + SEQ_printf(m, "Timer List Version: v0.7\n"); + SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); + SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); + SEQ_printf(m, "\n"); +} + static int timer_list_show(struct seq_file *m, void *v) { + struct timer_list_iter *iter = v; + u64 now = ktime_to_ns(ktime_get()); + + if (iter->cpu == -1 && !iter->second_pass) + timer_list_header(m, now); + else if (!iter->second_pass) + print_cpu(m, iter->cpu, iter->now); +#ifdef CONFIG_GENERIC_CLOCKEVENTS + else if (iter->cpu == -1 && iter->second_pass) + timer_list_show_tickdevices_header(m); + else + print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu); +#endif + return 0; +} + +void sysrq_timer_list_show(void) +{ u64 now = ktime_to_ns(ktime_get()); int cpu; - SEQ_printf(m, "Timer List Version: v0.7\n"); - SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); - SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); + timer_list_header(NULL, now); for_each_online_cpu(cpu) - print_cpu(m, cpu, now); + print_cpu(NULL, cpu, now); - SEQ_printf(m, "\n"); - timer_list_show_tickdevices(m); +#ifdef CONFIG_GENERIC_CLOCKEVENTS + timer_list_show_tickdevices_header(NULL); + for_each_online_cpu(cpu) + print_tickdevice(NULL, tick_get_device(cpu), cpu); +#endif + return; +} - return 0; +static void *timer_list_start(struct seq_file *file, loff_t *offset) +{ + struct timer_list_iter *iter = file->private; + + if (!*offset) { + iter->cpu = -1; + iter->now = ktime_to_ns(ktime_get()); + } else if (iter->cpu >= nr_cpu_ids) { +#ifdef CONFIG_GENERIC_CLOCKEVENTS + if (!iter->second_pass) { + iter->cpu = -1; + iter->second_pass = true; + } else + return NULL; +#else + return NULL; +#endif + } + return iter; } -void sysrq_timer_list_show(void) +static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset) +{ + struct timer_list_iter *iter = file->private; + iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); + ++*offset; + return timer_list_start(file, offset); +} + +static void timer_list_stop(struct seq_file *seq, void *v) { - timer_list_show(NULL, NULL); } +static const struct seq_operations timer_list_sops = { + .start = timer_list_start, + .next = timer_list_next, + .stop = timer_list_stop, + .show = timer_list_show, +}; + static int timer_list_open(struct inode *inode, struct file *filp) { - return single_open(filp, timer_list_show, NULL); + return seq_open_private(filp, &timer_list_sops, + sizeof(struct timer_list_iter)); } static const struct file_operations timer_list_fops = { .open = timer_list_open, .read = seq_read, .llseek = seq_lseek, - .release = single_release, + .release = seq_release_private, }; static int __init init_timer_list_procfs(void) diff --git a/kernel/timeconst.bc b/kernel/timeconst.bc new file mode 100644 index 000000000000..511bdf2cafda --- /dev/null +++ b/kernel/timeconst.bc @@ -0,0 +1,108 @@ +scale=0 + +define gcd(a,b) { + auto t; + while (b) { + t = b; + b = a % b; + a = t; + } + return a; +} + +/* Division by reciprocal multiplication. */ +define fmul(b,n,d) { + return (2^b*n+d-1)/d; +} + +/* Adjustment factor when a ceiling value is used. Use as: + (imul * n) + (fmulxx * n + fadjxx) >> xx) */ +define fadj(b,n,d) { + auto v; + d = d/gcd(n,d); + v = 2^b*(d-1)/d; + return v; +} + +/* Compute the appropriate mul/adj values as well as a shift count, + which brings the mul value into the range 2^b-1 <= x < 2^b. Such + a shift value will be correct in the signed integer range and off + by at most one in the upper half of the unsigned range. */ +define fmuls(b,n,d) { + auto s, m; + for (s = 0; 1; s++) { + m = fmul(s,n,d); + if (m >= 2^(b-1)) + return s; + } + return 0; +} + +define timeconst(hz) { + print "/* Automatically generated by kernel/timeconst.bc */\n" + print "/* Time conversion constants for HZ == ", hz, " */\n" + print "\n" + + print "#ifndef KERNEL_TIMECONST_H\n" + print "#define KERNEL_TIMECONST_H\n\n" + + print "#include <linux/param.h>\n" + print "#include <linux/types.h>\n\n" + + print "#if HZ != ", hz, "\n" + print "#error \qkernel/timeconst.h has the wrong HZ value!\q\n" + print "#endif\n\n" + + if (hz < 2) { + print "#error Totally bogus HZ value!\n" + } else { + s=fmuls(32,1000,hz) + obase=16 + print "#define HZ_TO_MSEC_MUL32\tU64_C(0x", fmul(s,1000,hz), ")\n" + print "#define HZ_TO_MSEC_ADJ32\tU64_C(0x", fadj(s,1000,hz), ")\n" + obase=10 + print "#define HZ_TO_MSEC_SHR32\t", s, "\n" + + s=fmuls(32,hz,1000) + obase=16 + print "#define MSEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000), ")\n" + print "#define MSEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000), ")\n" + obase=10 + print "#define MSEC_TO_HZ_SHR32\t", s, "\n" + + obase=10 + cd=gcd(hz,1000) + print "#define HZ_TO_MSEC_NUM\t\t", 1000/cd, "\n" + print "#define HZ_TO_MSEC_DEN\t\t", hz/cd, "\n" + print "#define MSEC_TO_HZ_NUM\t\t", hz/cd, "\n" + print "#define MSEC_TO_HZ_DEN\t\t", 1000/cd, "\n" + print "\n" + + s=fmuls(32,1000000,hz) + obase=16 + print "#define HZ_TO_USEC_MUL32\tU64_C(0x", fmul(s,1000000,hz), ")\n" + print "#define HZ_TO_USEC_ADJ32\tU64_C(0x", fadj(s,1000000,hz), ")\n" + obase=10 + print "#define HZ_TO_USEC_SHR32\t", s, "\n" + + s=fmuls(32,hz,1000000) + obase=16 + print "#define USEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000000), ")\n" + print "#define USEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000000), ")\n" + obase=10 + print "#define USEC_TO_HZ_SHR32\t", s, "\n" + + obase=10 + cd=gcd(hz,1000000) + print "#define HZ_TO_USEC_NUM\t\t", 1000000/cd, "\n" + print "#define HZ_TO_USEC_DEN\t\t", hz/cd, "\n" + print "#define USEC_TO_HZ_NUM\t\t", hz/cd, "\n" + print "#define USEC_TO_HZ_DEN\t\t", 1000000/cd, "\n" + print "\n" + + print "#endif /* KERNEL_TIMECONST_H */\n" + } + halt +} + +timeconst(hz) diff --git a/kernel/timeconst.pl b/kernel/timeconst.pl deleted file mode 100644 index eb51d76e058a..000000000000 --- a/kernel/timeconst.pl +++ /dev/null @@ -1,378 +0,0 @@ -#!/usr/bin/perl -# ----------------------------------------------------------------------- -# -# Copyright 2007-2008 rPath, Inc. - All Rights Reserved -# -# This file is part of the Linux kernel, and is made available under -# the terms of the GNU General Public License version 2 or (at your -# option) any later version; incorporated herein by reference. -# -# ----------------------------------------------------------------------- -# - -# -# Usage: timeconst.pl HZ > timeconst.h -# - -# Precomputed values for systems without Math::BigInt -# Generated by: -# timeconst.pl --can 24 32 48 64 100 122 128 200 250 256 300 512 1000 1024 1200 -%canned_values = ( - 24 => [ - '0xa6aaaaab','0x2aaaaaa',26, - 125,3, - '0xc49ba5e4','0x1fbe76c8b4',37, - 3,125, - '0xa2c2aaab','0xaaaa',16, - 125000,3, - '0xc9539b89','0x7fffbce4217d',47, - 3,125000, - ], 32 => [ - '0xfa000000','0x6000000',27, - 125,4, - '0x83126e98','0xfdf3b645a',36, - 4,125, - '0xf4240000','0x0',17, - 31250,1, - '0x8637bd06','0x3fff79c842fa',46, - 1,31250, - ], 48 => [ - '0xa6aaaaab','0x6aaaaaa',27, - 125,6, - '0xc49ba5e4','0xfdf3b645a',36, - 6,125, - '0xa2c2aaab','0x15555',17, - 62500,3, - '0xc9539b89','0x3fffbce4217d',46, - 3,62500, - ], 64 => [ - '0xfa000000','0xe000000',28, - 125,8, - '0x83126e98','0x7ef9db22d',35, - 8,125, - '0xf4240000','0x0',18, - 15625,1, - '0x8637bd06','0x1fff79c842fa',45, - 1,15625, - ], 100 => [ - '0xa0000000','0x0',28, - 10,1, - '0xcccccccd','0x733333333',35, - 1,10, - '0x9c400000','0x0',18, - 10000,1, - '0xd1b71759','0x1fff2e48e8a7',45, - 1,10000, - ], 122 => [ - '0x8325c53f','0xfbcda3a',28, - 500,61, - '0xf9db22d1','0x7fbe76c8b',35, - 61,500, - '0x8012e2a0','0x3ef36',18, - 500000,61, - '0xffda4053','0x1ffffbce4217',45, - 61,500000, - ], 128 => [ - '0xfa000000','0x1e000000',29, - 125,16, - '0x83126e98','0x3f7ced916',34, - 16,125, - '0xf4240000','0x40000',19, - 15625,2, - '0x8637bd06','0xfffbce4217d',44, - 2,15625, - ], 200 => [ - '0xa0000000','0x0',29, - 5,1, - '0xcccccccd','0x333333333',34, - 1,5, - '0x9c400000','0x0',19, - 5000,1, - '0xd1b71759','0xfff2e48e8a7',44, - 1,5000, - ], 250 => [ - '0x80000000','0x0',29, - 4,1, - '0x80000000','0x180000000',33, - 1,4, - '0xfa000000','0x0',20, - 4000,1, - '0x83126e98','0x7ff7ced9168',43, - 1,4000, - ], 256 => [ - '0xfa000000','0x3e000000',30, - 125,32, - '0x83126e98','0x1fbe76c8b',33, - 32,125, - '0xf4240000','0xc0000',20, - 15625,4, - '0x8637bd06','0x7ffde7210be',43, - 4,15625, - ], 300 => [ - '0xd5555556','0x2aaaaaaa',30, - 10,3, - '0x9999999a','0x1cccccccc',33, - 3,10, - '0xd0555556','0xaaaaa',20, - 10000,3, - '0x9d495183','0x7ffcb923a29',43, - 3,10000, - ], 512 => [ - '0xfa000000','0x7e000000',31, - 125,64, - '0x83126e98','0xfdf3b645',32, - 64,125, - '0xf4240000','0x1c0000',21, - 15625,8, - '0x8637bd06','0x3ffef39085f',42, - 8,15625, - ], 1000 => [ - '0x80000000','0x0',31, - 1,1, - '0x80000000','0x0',31, - 1,1, - '0xfa000000','0x0',22, - 1000,1, - '0x83126e98','0x1ff7ced9168',41, - 1,1000, - ], 1024 => [ - '0xfa000000','0xfe000000',32, - 125,128, - '0x83126e98','0x7ef9db22',31, - 128,125, - '0xf4240000','0x3c0000',22, - 15625,16, - '0x8637bd06','0x1fff79c842f',41, - 16,15625, - ], 1200 => [ - '0xd5555556','0xd5555555',32, - 5,6, - '0x9999999a','0x66666666',31, - 6,5, - '0xd0555556','0x2aaaaa',22, - 2500,3, - '0x9d495183','0x1ffcb923a29',41, - 3,2500, - ] -); - -$has_bigint = eval 'use Math::BigInt qw(bgcd); 1;'; - -sub bint($) -{ - my($x) = @_; - return Math::BigInt->new($x); -} - -# -# Constants for division by reciprocal multiplication. -# (bits, numerator, denominator) -# -sub fmul($$$) -{ - my ($b,$n,$d) = @_; - - $n = bint($n); - $d = bint($d); - - return scalar (($n << $b)+$d-bint(1))/$d; -} - -sub fadj($$$) -{ - my($b,$n,$d) = @_; - - $n = bint($n); - $d = bint($d); - - $d = $d/bgcd($n, $d); - return scalar (($d-bint(1)) << $b)/$d; -} - -sub fmuls($$$) { - my($b,$n,$d) = @_; - my($s,$m); - my($thres) = bint(1) << ($b-1); - - $n = bint($n); - $d = bint($d); - - for ($s = 0; 1; $s++) { - $m = fmul($s,$n,$d); - return $s if ($m >= $thres); - } - return 0; -} - -# Generate a hex value if the result fits in 64 bits; -# otherwise skip. -sub bignum_hex($) { - my($x) = @_; - my $s = $x->as_hex(); - - return (length($s) > 18) ? undef : $s; -} - -# Provides mul, adj, and shr factors for a specific -# (bit, time, hz) combination -sub muladj($$$) { - my($b, $t, $hz) = @_; - my $s = fmuls($b, $t, $hz); - my $m = fmul($s, $t, $hz); - my $a = fadj($s, $t, $hz); - return (bignum_hex($m), bignum_hex($a), $s); -} - -# Provides numerator, denominator values -sub numden($$) { - my($n, $d) = @_; - my $g = bgcd($n, $d); - return ($n/$g, $d/$g); -} - -# All values for a specific (time, hz) combo -sub conversions($$) { - my ($t, $hz) = @_; - my @val = (); - - # HZ_TO_xx - push(@val, muladj(32, $t, $hz)); - push(@val, numden($t, $hz)); - - # xx_TO_HZ - push(@val, muladj(32, $hz, $t)); - push(@val, numden($hz, $t)); - - return @val; -} - -sub compute_values($) { - my($hz) = @_; - my @val = (); - my $s, $m, $a, $g; - - if (!$has_bigint) { - die "$0: HZ == $hz not canned and ". - "Math::BigInt not available\n"; - } - - # MSEC conversions - push(@val, conversions(1000, $hz)); - - # USEC conversions - push(@val, conversions(1000000, $hz)); - - return @val; -} - -sub outputval($$) -{ - my($name, $val) = @_; - my $csuf; - - if (defined($val)) { - if ($name !~ /SHR/) { - $val = "U64_C($val)"; - } - printf "#define %-23s %s\n", $name.$csuf, $val.$csuf; - } -} - -sub output($@) -{ - my($hz, @val) = @_; - my $pfx, $bit, $suf, $s, $m, $a; - - print "/* Automatically generated by kernel/timeconst.pl */\n"; - print "/* Conversion constants for HZ == $hz */\n"; - print "\n"; - print "#ifndef KERNEL_TIMECONST_H\n"; - print "#define KERNEL_TIMECONST_H\n"; - print "\n"; - - print "#include <linux/param.h>\n"; - print "#include <linux/types.h>\n"; - - print "\n"; - print "#if HZ != $hz\n"; - print "#error \"kernel/timeconst.h has the wrong HZ value!\"\n"; - print "#endif\n"; - print "\n"; - - foreach $pfx ('HZ_TO_MSEC','MSEC_TO_HZ', - 'HZ_TO_USEC','USEC_TO_HZ') { - foreach $bit (32) { - foreach $suf ('MUL', 'ADJ', 'SHR') { - outputval("${pfx}_$suf$bit", shift(@val)); - } - } - foreach $suf ('NUM', 'DEN') { - outputval("${pfx}_$suf", shift(@val)); - } - } - - print "\n"; - print "#endif /* KERNEL_TIMECONST_H */\n"; -} - -# Pretty-print Perl values -sub perlvals(@) { - my $v; - my @l = (); - - foreach $v (@_) { - if (!defined($v)) { - push(@l, 'undef'); - } elsif ($v =~ /^0x/) { - push(@l, "\'".$v."\'"); - } else { - push(@l, $v.''); - } - } - return join(',', @l); -} - -($hz) = @ARGV; - -# Use this to generate the %canned_values structure -if ($hz eq '--can') { - shift(@ARGV); - @hzlist = sort {$a <=> $b} (@ARGV); - - print "# Precomputed values for systems without Math::BigInt\n"; - print "# Generated by:\n"; - print "# timeconst.pl --can ", join(' ', @hzlist), "\n"; - print "\%canned_values = (\n"; - my $pf = "\t"; - foreach $hz (@hzlist) { - my @values = compute_values($hz); - print "$pf$hz => [\n"; - while (scalar(@values)) { - my $bit; - foreach $bit (32) { - my $m = shift(@values); - my $a = shift(@values); - my $s = shift(@values); - print "\t\t", perlvals($m,$a,$s), ",\n"; - } - my $n = shift(@values); - my $d = shift(@values); - print "\t\t", perlvals($n,$d), ",\n"; - } - print "\t]"; - $pf = ', '; - } - print "\n);\n"; -} else { - $hz += 0; # Force to number - if ($hz < 1) { - die "Usage: $0 HZ\n"; - } - - @val = @{$canned_values{$hz}}; - if (!defined(@val)) { - @val = compute_values($hz); - } - output($hz, @val); -} -exit 0; diff --git a/kernel/timer.c b/kernel/timer.c index 367d00858482..a860bba34412 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1,7 +1,7 @@ /* * linux/kernel/timer.c * - * Kernel internal timers, basic process system calls + * Kernel internal timers * * Copyright (C) 1991, 1992 Linus Torvalds * @@ -39,7 +39,9 @@ #include <linux/kallsyms.h> #include <linux/irq_work.h> #include <linux/sched.h> +#include <linux/sched/sysctl.h> #include <linux/slab.h> +#include <linux/compat.h> #include <asm/uaccess.h> #include <asm/unistd.h> @@ -737,7 +739,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires, cpu = smp_processor_id(); -#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP) +#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP) if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu)) cpu = get_nohz_timer_target(); #endif @@ -929,14 +931,14 @@ void add_timer_on(struct timer_list *timer, int cpu) debug_activate(timer, timer->expires); internal_add_timer(base, timer); /* - * Check whether the other CPU is idle and needs to be - * triggered to reevaluate the timer wheel when nohz is - * active. We are protected against the other CPU fiddling + * Check whether the other CPU is in dynticks mode and needs + * to be triggered to reevaluate the timer wheel. + * We are protected against the other CPU fiddling * with the timer by holding the timer base lock. This also - * makes sure that a CPU on the way to idle can not evaluate - * the timer wheel. + * makes sure that a CPU on the way to stop its tick can not + * evaluate the timer wheel. */ - wake_up_idle_cpu(cpu); + wake_up_nohz_cpu(cpu); spin_unlock_irqrestore(&base->lock, flags); } EXPORT_SYMBOL_GPL(add_timer_on); @@ -1187,7 +1189,7 @@ static inline void __run_timers(struct tvec_base *base) spin_unlock_irq(&base->lock); } -#ifdef CONFIG_NO_HZ +#ifdef CONFIG_NO_HZ_COMMON /* * Find out when the next timer event is due to happen. This * is used on S/390 to stop all activity when a CPU is idle. @@ -1351,7 +1353,6 @@ void update_process_times(int user_tick) account_process_tick(p, user_tick); run_local_timers(); rcu_check_callbacks(cpu, user_tick); - printk_tick(); #ifdef CONFIG_IRQ_WORK if (in_irq()) irq_work_run(); @@ -1395,61 +1396,6 @@ SYSCALL_DEFINE1(alarm, unsigned int, seconds) #endif -/** - * sys_getpid - return the thread group id of the current process - * - * Note, despite the name, this returns the tgid not the pid. The tgid and - * the pid are identical unless CLONE_THREAD was specified on clone() in - * which case the tgid is the same in all threads of the same group. - * - * This is SMP safe as current->tgid does not change. - */ -SYSCALL_DEFINE0(getpid) -{ - return task_tgid_vnr(current); -} - -/* - * Accessing ->real_parent is not SMP-safe, it could - * change from under us. However, we can use a stale - * value of ->real_parent under rcu_read_lock(), see - * release_task()->call_rcu(delayed_put_task_struct). - */ -SYSCALL_DEFINE0(getppid) -{ - int pid; - - rcu_read_lock(); - pid = task_tgid_vnr(rcu_dereference(current->real_parent)); - rcu_read_unlock(); - - return pid; -} - -SYSCALL_DEFINE0(getuid) -{ - /* Only we change this so SMP safe */ - return from_kuid_munged(current_user_ns(), current_uid()); -} - -SYSCALL_DEFINE0(geteuid) -{ - /* Only we change this so SMP safe */ - return from_kuid_munged(current_user_ns(), current_euid()); -} - -SYSCALL_DEFINE0(getgid) -{ - /* Only we change this so SMP safe */ - return from_kgid_munged(current_user_ns(), current_gid()); -} - -SYSCALL_DEFINE0(getegid) -{ - /* Only we change this so SMP safe */ - return from_kgid_munged(current_user_ns(), current_egid()); -} - static void process_timeout(unsigned long __data) { wake_up_process((struct task_struct *)__data); @@ -1557,91 +1503,6 @@ signed long __sched schedule_timeout_uninterruptible(signed long timeout) } EXPORT_SYMBOL(schedule_timeout_uninterruptible); -/* Thread ID - the internal kernel "pid" */ -SYSCALL_DEFINE0(gettid) -{ - return task_pid_vnr(current); -} - -/** - * do_sysinfo - fill in sysinfo struct - * @info: pointer to buffer to fill - */ -int do_sysinfo(struct sysinfo *info) -{ - unsigned long mem_total, sav_total; - unsigned int mem_unit, bitcount; - struct timespec tp; - - memset(info, 0, sizeof(struct sysinfo)); - - ktime_get_ts(&tp); - monotonic_to_bootbased(&tp); - info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); - - get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); - - info->procs = nr_threads; - - si_meminfo(info); - si_swapinfo(info); - - /* - * If the sum of all the available memory (i.e. ram + swap) - * is less than can be stored in a 32 bit unsigned long then - * we can be binary compatible with 2.2.x kernels. If not, - * well, in that case 2.2.x was broken anyways... - * - * -Erik Andersen <andersee@debian.org> - */ - - mem_total = info->totalram + info->totalswap; - if (mem_total < info->totalram || mem_total < info->totalswap) - goto out; - bitcount = 0; - mem_unit = info->mem_unit; - while (mem_unit > 1) { - bitcount++; - mem_unit >>= 1; - sav_total = mem_total; - mem_total <<= 1; - if (mem_total < sav_total) - goto out; - } - - /* - * If mem_total did not overflow, multiply all memory values by - * info->mem_unit and set it to 1. This leaves things compatible - * with 2.2.x, and also retains compatibility with earlier 2.4.x - * kernels... - */ - - info->mem_unit = 1; - info->totalram <<= bitcount; - info->freeram <<= bitcount; - info->sharedram <<= bitcount; - info->bufferram <<= bitcount; - info->totalswap <<= bitcount; - info->freeswap <<= bitcount; - info->totalhigh <<= bitcount; - info->freehigh <<= bitcount; - -out: - return 0; -} - -SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) -{ - struct sysinfo val; - - do_sysinfo(&val); - - if (copy_to_user(info, &val, sizeof(struct sysinfo))) - return -EFAULT; - - return 0; -} - static int __cpuinit init_timers_cpu(int cpu) { int j; diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 5d89335a485f..5e9efd4b83a4 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -39,6 +39,9 @@ config HAVE_DYNAMIC_FTRACE help See Documentation/trace/ftrace-design.txt +config HAVE_DYNAMIC_FTRACE_WITH_REGS + bool + config HAVE_FTRACE_MCOUNT_RECORD bool help @@ -78,21 +81,6 @@ config EVENT_TRACING select CONTEXT_SWITCH_TRACER bool -config EVENT_POWER_TRACING_DEPRECATED - depends on EVENT_TRACING - bool "Deprecated power event trace API, to be removed" - default y - help - Provides old power event types: - C-state/idle accounting events: - power:power_start - power:power_end - and old cpufreq accounting event: - power:power_frequency - This is for userspace compatibility - and will vanish after 5 kernel iterations, - namely 3.1. - config CONTEXT_SWITCH_TRACER bool @@ -188,6 +176,8 @@ config IRQSOFF_TRACER select GENERIC_TRACER select TRACER_MAX_TRACE select RING_BUFFER_ALLOW_SWAP + select TRACER_SNAPSHOT + select TRACER_SNAPSHOT_PER_CPU_SWAP help This option measures the time spent in irqs-off critical sections, with microsecond accuracy. @@ -210,6 +200,8 @@ config PREEMPT_TRACER select GENERIC_TRACER select TRACER_MAX_TRACE select RING_BUFFER_ALLOW_SWAP + select TRACER_SNAPSHOT + select TRACER_SNAPSHOT_PER_CPU_SWAP help This option measures the time spent in preemption-off critical sections, with microsecond accuracy. @@ -229,6 +221,7 @@ config SCHED_TRACER select GENERIC_TRACER select CONTEXT_SWITCH_TRACER select TRACER_MAX_TRACE + select TRACER_SNAPSHOT help This tracer tracks the latency of the highest priority task to be scheduled in, starting from the point it has woken up. @@ -250,6 +243,37 @@ config FTRACE_SYSCALLS help Basic tracer to catch the syscall entry and exit events. +config TRACER_SNAPSHOT + bool "Create a snapshot trace buffer" + select TRACER_MAX_TRACE + help + Allow tracing users to take snapshot of the current buffer using the + ftrace interface, e.g.: + + echo 1 > /sys/kernel/debug/tracing/snapshot + cat snapshot + +config TRACER_SNAPSHOT_PER_CPU_SWAP + bool "Allow snapshot to swap per CPU" + depends on TRACER_SNAPSHOT + select RING_BUFFER_ALLOW_SWAP + help + Allow doing a snapshot of a single CPU buffer instead of a + full swap (all buffers). If this is set, then the following is + allowed: + + echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot + + After which, only the tracing buffer for CPU 2 was swapped with + the main tracing buffer, and the other CPU buffers remain the same. + + When this is enabled, this adds a little more overhead to the + trace recording, as it needs to add some checks to synchronize + recording with swaps. But this does not affect the performance + of the overall system. This is enabled by default when the preempt + or irq latency tracers are enabled, as those need to swap as well + and already adds the overhead (plus a lot more). + config TRACE_BRANCH_PROFILING bool select GENERIC_TRACER @@ -416,23 +440,32 @@ config PROBE_EVENTS def_bool n config DYNAMIC_FTRACE - bool "enable/disable ftrace tracepoints dynamically" + bool "enable/disable function tracing dynamically" depends on FUNCTION_TRACER depends on HAVE_DYNAMIC_FTRACE default y help - This option will modify all the calls to ftrace dynamically - (will patch them out of the binary image and replace them - with a No-Op instruction) as they are called. A table is - created to dynamically enable them again. + This option will modify all the calls to function tracing + dynamically (will patch them out of the binary image and + replace them with a No-Op instruction) on boot up. During + compile time, a table is made of all the locations that ftrace + can function trace, and this table is linked into the kernel + image. When this is enabled, functions can be individually + enabled, and the functions not enabled will not affect + performance of the system. + + See the files in /sys/kernel/debug/tracing: + available_filter_functions + set_ftrace_filter + set_ftrace_notrace This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but otherwise has native performance as long as no tracing is active. - The changes to the code are done by a kernel thread that - wakes up once a second and checks to see if any ftrace calls - were made. If so, it runs stop_machine (stops all CPUS) - and modifies the code to jump over the call to ftrace. +config DYNAMIC_FTRACE_WITH_REGS + def_bool y + depends on DYNAMIC_FTRACE + depends on HAVE_DYNAMIC_FTRACE_WITH_REGS config FUNCTION_PROFILER bool "Kernel function profiler" @@ -517,6 +550,29 @@ config RING_BUFFER_BENCHMARK If unsure, say N. +config RING_BUFFER_STARTUP_TEST + bool "Ring buffer startup self test" + depends on RING_BUFFER + help + Run a simple self test on the ring buffer on boot up. Late in the + kernel boot sequence, the test will start that kicks off + a thread per cpu. Each thread will write various size events + into the ring buffer. Another thread is created to send IPIs + to each of the threads, where the IPI handler will also write + to the ring buffer, to test/stress the nesting ability. + If any anomalies are discovered, a warning will be displayed + and all ring buffers will be disabled. + + The test runs for 10 seconds. This will slow your boot time + by at least 10 more seconds. + + At the end of the test, statics and more checks are done. + It will output the stats of each per cpu buffer. What + was written, the sizes, what was read, what was lost, and + other similar details. + + If unsure, say N + endif # FTRACE endif # TRACING_SUPPORT diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index c0bd0308741c..b8b8560bfb95 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -72,7 +72,7 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action, bool blk_tracer = blk_tracer_enabled; if (blk_tracer) { - buffer = blk_tr->buffer; + buffer = blk_tr->trace_buffer.buffer; pc = preempt_count(); event = trace_buffer_lock_reserve(buffer, TRACE_BLK, sizeof(*t) + len, @@ -147,7 +147,7 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...) return; local_irq_save(flags); - buf = per_cpu_ptr(bt->msg_data, smp_processor_id()); + buf = this_cpu_ptr(bt->msg_data); va_start(args, fmt); n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); va_end(args); @@ -218,7 +218,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, if (blk_tracer) { tracing_record_cmdline(current); - buffer = blk_tr->buffer; + buffer = blk_tr->trace_buffer.buffer; pc = preempt_count(); event = trace_buffer_lock_reserve(buffer, TRACE_BLK, sizeof(*t) + pdu_len, @@ -783,6 +783,7 @@ static void blk_add_trace_bio_complete(void *ignore, static void blk_add_trace_bio_backmerge(void *ignore, struct request_queue *q, + struct request *rq, struct bio *bio) { blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0); @@ -790,6 +791,7 @@ static void blk_add_trace_bio_backmerge(void *ignore, static void blk_add_trace_bio_frontmerge(void *ignore, struct request_queue *q, + struct request *rq, struct bio *bio) { blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE, 0); @@ -1806,6 +1808,7 @@ void blk_fill_rwbs(char *rwbs, u32 rw, int bytes) rwbs[i] = '\0'; } +EXPORT_SYMBOL_GPL(blk_fill_rwbs); #endif /* CONFIG_EVENT_TRACING */ diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 41473b4ad7a4..8a5c017bb50c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -66,7 +66,7 @@ static struct ftrace_ops ftrace_list_end __read_mostly = { .func = ftrace_stub, - .flags = FTRACE_OPS_FL_RECURSION_SAFE, + .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, }; /* ftrace_enabled is a method to turn ftrace on or off */ @@ -111,6 +111,26 @@ static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) #endif +/* + * Traverse the ftrace_global_list, invoking all entries. The reason that we + * can use rcu_dereference_raw() is that elements removed from this list + * are simply leaked, so there is no need to interact with a grace-period + * mechanism. The rcu_dereference_raw() calls are needed to handle + * concurrent insertions into the ftrace_global_list. + * + * Silly Alpha and silly pointer-speculation compiler optimizations! + */ +#define do_for_each_ftrace_op(op, list) \ + op = rcu_dereference_raw(list); \ + do + +/* + * Optimized for just a single item in the list (as that is the normal case). + */ +#define while_for_each_ftrace_op(op) \ + while (likely(op = rcu_dereference_raw((op)->next)) && \ + unlikely((op) != &ftrace_list_end)) + /** * ftrace_nr_registered_ops - return number of ops registered * @@ -132,29 +152,21 @@ int ftrace_nr_registered_ops(void) return cnt; } -/* - * Traverse the ftrace_global_list, invoking all entries. The reason that we - * can use rcu_dereference_raw() is that elements removed from this list - * are simply leaked, so there is no need to interact with a grace-period - * mechanism. The rcu_dereference_raw() calls are needed to handle - * concurrent insertions into the ftrace_global_list. - * - * Silly Alpha and silly pointer-speculation compiler optimizations! - */ static void ftrace_global_list_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *regs) { - if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT))) + int bit; + + bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX); + if (bit < 0) return; - trace_recursion_set(TRACE_GLOBAL_BIT); - op = rcu_dereference_raw(ftrace_global_list); /*see above*/ - while (op != &ftrace_list_end) { + do_for_each_ftrace_op(op, ftrace_global_list) { op->func(ip, parent_ip, op, regs); - op = rcu_dereference_raw(op->next); /*see above*/ - }; - trace_recursion_clear(TRACE_GLOBAL_BIT); + } while_for_each_ftrace_op(op); + + trace_clear_recursion(bit); } static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, @@ -221,10 +233,24 @@ static void update_global_ops(void) * registered callers. */ if (ftrace_global_list == &ftrace_list_end || - ftrace_global_list->next == &ftrace_list_end) + ftrace_global_list->next == &ftrace_list_end) { func = ftrace_global_list->func; - else + /* + * As we are calling the function directly. + * If it does not have recursion protection, + * the function_trace_op needs to be updated + * accordingly. + */ + if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) + global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; + else + global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE; + } else { func = ftrace_global_list_func; + /* The list has its own recursion protection. */ + global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; + } + /* If we filter on pids, update to use the pid function */ if (!list_empty(&ftrace_pids)) { @@ -337,7 +363,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK) return -EINVAL; -#ifndef ARCH_SUPPORTS_FTRACE_SAVE_REGS +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS /* * If the ftrace_ops specifies SAVE_REGS, then it only can be used * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. @@ -460,7 +486,6 @@ struct ftrace_profile_stat { #define PROFILES_PER_PAGE \ (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) -static int ftrace_profile_bits __read_mostly; static int ftrace_profile_enabled __read_mostly; /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ @@ -468,7 +493,8 @@ static DEFINE_MUTEX(ftrace_profile_lock); static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); -#define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ +#define FTRACE_PROFILE_HASH_BITS 10 +#define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) static void * function_stat_next(void *v, int idx) @@ -650,7 +676,7 @@ int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); - for (i = 0; i < pages; i++) { + for (i = 1; i < pages; i++) { pg->next = (void *)get_zeroed_page(GFP_KERNEL); if (!pg->next) goto out_free; @@ -668,7 +694,6 @@ int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) free_page(tmp); } - free_page((unsigned long)stat->pages); stat->pages = NULL; stat->start = NULL; @@ -699,13 +724,6 @@ static int ftrace_profile_init_cpu(int cpu) if (!stat->hash) return -ENOMEM; - if (!ftrace_profile_bits) { - size--; - - for (; size; size >>= 1) - ftrace_profile_bits++; - } - /* Preallocate the function profiling pages */ if (ftrace_profile_pages_init(stat) < 0) { kfree(stat->hash); @@ -736,16 +754,15 @@ ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) { struct ftrace_profile *rec; struct hlist_head *hhd; - struct hlist_node *n; unsigned long key; - key = hash_long(ip, ftrace_profile_bits); + key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); hhd = &stat->hash[key]; if (hlist_empty(hhd)) return NULL; - hlist_for_each_entry_rcu(rec, n, hhd, node) { + hlist_for_each_entry_rcu(rec, hhd, node) { if (rec->ip == ip) return rec; } @@ -758,7 +775,7 @@ static void ftrace_add_profile(struct ftrace_profile_stat *stat, { unsigned long key; - key = hash_long(rec->ip, ftrace_profile_bits); + key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); hlist_add_head_rcu(&rec->node, &stat->hash[key]); } @@ -1028,6 +1045,19 @@ static __init void ftrace_profile_debugfs(struct dentry *d_tracer) static struct pid * const ftrace_swapper_pid = &init_struct_pid; +loff_t +ftrace_filter_lseek(struct file *file, loff_t offset, int whence) +{ + loff_t ret; + + if (file->f_mode & FMODE_READ) + ret = seq_lseek(file, offset, whence); + else + file->f_pos = ret = 1; + + return ret; +} + #ifdef CONFIG_DYNAMIC_FTRACE #ifndef CONFIG_FTRACE_MCOUNT_RECORD @@ -1042,7 +1072,7 @@ struct ftrace_func_probe { unsigned long flags; unsigned long ip; void *data; - struct rcu_head rcu; + struct list_head free_list; }; struct ftrace_func_entry { @@ -1107,7 +1137,6 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) unsigned long key; struct ftrace_func_entry *entry; struct hlist_head *hhd; - struct hlist_node *n; if (ftrace_hash_empty(hash)) return NULL; @@ -1119,7 +1148,7 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) hhd = &hash->buckets[key]; - hlist_for_each_entry_rcu(entry, n, hhd, hlist) { + hlist_for_each_entry_rcu(entry, hhd, hlist) { if (entry->ip == ip) return entry; } @@ -1176,7 +1205,7 @@ remove_hash_entry(struct ftrace_hash *hash, static void ftrace_hash_clear(struct ftrace_hash *hash) { struct hlist_head *hhd; - struct hlist_node *tp, *tn; + struct hlist_node *tn; struct ftrace_func_entry *entry; int size = 1 << hash->size_bits; int i; @@ -1186,7 +1215,7 @@ static void ftrace_hash_clear(struct ftrace_hash *hash) for (i = 0; i < size; i++) { hhd = &hash->buckets[i]; - hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) + hlist_for_each_entry_safe(entry, tn, hhd, hlist) free_hash_entry(hash, entry); } FTRACE_WARN_ON(hash->count); @@ -1249,7 +1278,6 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) { struct ftrace_func_entry *entry; struct ftrace_hash *new_hash; - struct hlist_node *tp; int size; int ret; int i; @@ -1264,7 +1292,7 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) size = 1 << hash->size_bits; for (i = 0; i < size; i++) { - hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { ret = add_hash_entry(new_hash, entry->ip); if (ret < 0) goto free_hash; @@ -1290,11 +1318,10 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable, struct ftrace_hash **dst, struct ftrace_hash *src) { struct ftrace_func_entry *entry; - struct hlist_node *tp, *tn; + struct hlist_node *tn; struct hlist_head *hhd; struct ftrace_hash *old_hash; struct ftrace_hash *new_hash; - unsigned long key; int size = src->count; int bits = 0; int ret; @@ -1336,11 +1363,7 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable, size = 1 << src->size_bits; for (i = 0; i < size; i++) { hhd = &src->buckets[i]; - hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) { - if (bits > 0) - key = hash_long(entry->ip, bits); - else - key = 0; + hlist_for_each_entry_safe(entry, tn, hhd, hlist) { remove_hash_entry(src, entry); __add_hash_entry(new_hash, entry); } @@ -2590,7 +2613,7 @@ static void ftrace_filter_reset(struct ftrace_hash *hash) * routine, you can use ftrace_filter_write() for the write * routine if @flag has FTRACE_ITER_FILTER set, or * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. - * ftrace_regex_lseek() should be used as the lseek routine, and + * ftrace_filter_lseek() should be used as the lseek routine, and * release must call ftrace_regex_release(). */ int @@ -2674,19 +2697,6 @@ ftrace_notrace_open(struct inode *inode, struct file *file) inode, file); } -loff_t -ftrace_regex_lseek(struct file *file, loff_t offset, int whence) -{ - loff_t ret; - - if (file->f_mode & FMODE_READ) - ret = seq_lseek(file, offset, whence); - else - file->f_pos = ret = 1; - - return ret; -} - static int ftrace_match(char *str, char *regex, int len, int type) { int matched = 0; @@ -2875,7 +2885,6 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, { struct ftrace_func_probe *entry; struct hlist_head *hhd; - struct hlist_node *n; unsigned long key; key = hash_long(ip, FTRACE_HASH_BITS); @@ -2891,7 +2900,7 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, * on the hash. rcu_read_lock is too dangerous here. */ preempt_disable_notrace(); - hlist_for_each_entry_rcu(entry, n, hhd, node) { + hlist_for_each_entry_rcu(entry, hhd, node) { if (entry->ip == ip) entry->ops->func(ip, parent_ip, &entry->data); } @@ -2952,28 +2961,27 @@ static void __disable_ftrace_function_probe(void) } -static void ftrace_free_entry_rcu(struct rcu_head *rhp) +static void ftrace_free_entry(struct ftrace_func_probe *entry) { - struct ftrace_func_probe *entry = - container_of(rhp, struct ftrace_func_probe, rcu); - if (entry->ops->free) - entry->ops->free(&entry->data); + entry->ops->free(entry->ops, entry->ip, &entry->data); kfree(entry); } - int register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, void *data) { struct ftrace_func_probe *entry; + struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; + struct ftrace_hash *hash; struct ftrace_page *pg; struct dyn_ftrace *rec; int type, len, not; unsigned long key; int count = 0; char *search; + int ret; type = filter_parse_regex(glob, strlen(glob), &search, ¬); len = strlen(search); @@ -2984,8 +2992,16 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, mutex_lock(&ftrace_lock); - if (unlikely(ftrace_disabled)) + hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); + if (!hash) { + count = -ENOMEM; + goto out_unlock; + } + + if (unlikely(ftrace_disabled)) { + count = -ENODEV; goto out_unlock; + } do_for_each_ftrace_rec(pg, rec) { @@ -3009,14 +3025,21 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, * for each function we find. We call the callback * to give the caller an opportunity to do so. */ - if (ops->callback) { - if (ops->callback(rec->ip, &entry->data) < 0) { + if (ops->init) { + if (ops->init(ops, rec->ip, &entry->data) < 0) { /* caller does not like this func */ kfree(entry); continue; } } + ret = enter_record(hash, rec, 0); + if (ret < 0) { + kfree(entry); + count = ret; + goto out_unlock; + } + entry->ops = ops; entry->ip = rec->ip; @@ -3024,10 +3047,16 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); } while_for_each_ftrace_rec(); + + ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); + if (ret < 0) + count = ret; + __enable_ftrace_function_probe(); out_unlock: mutex_unlock(&ftrace_lock); + free_ftrace_hash(hash); return count; } @@ -3041,8 +3070,13 @@ static void __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, void *data, int flags) { + struct ftrace_func_entry *rec_entry; struct ftrace_func_probe *entry; - struct hlist_node *n, *tmp; + struct ftrace_func_probe *p; + struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; + struct list_head free_list; + struct ftrace_hash *hash; + struct hlist_node *tmp; char str[KSYM_SYMBOL_LEN]; int type = MATCH_FULL; int i, len = 0; @@ -3062,10 +3096,18 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, } mutex_lock(&ftrace_lock); + + hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); + if (!hash) + /* Hmm, should report this somehow */ + goto out_unlock; + + INIT_LIST_HEAD(&free_list); + for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { struct hlist_head *hhd = &ftrace_func_hash[i]; - hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { + hlist_for_each_entry_safe(entry, tmp, hhd, node) { /* break up if statements for readability */ if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) @@ -3082,12 +3124,30 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, continue; } - hlist_del(&entry->node); - call_rcu(&entry->rcu, ftrace_free_entry_rcu); + rec_entry = ftrace_lookup_ip(hash, entry->ip); + /* It is possible more than one entry had this ip */ + if (rec_entry) + free_hash_entry(hash, rec_entry); + + hlist_del_rcu(&entry->node); + list_add(&entry->free_list, &free_list); } } __disable_ftrace_function_probe(); + /* + * Remove after the disable is called. Otherwise, if the last + * probe is removed, a null hash means *all enabled*. + */ + ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); + synchronize_sched(); + list_for_each_entry_safe(entry, p, &free_list, free_list) { + list_del(&entry->free_list); + ftrace_free_entry(entry); + } + + out_unlock: mutex_unlock(&ftrace_lock); + free_ftrace_hash(hash); } void @@ -3419,14 +3479,14 @@ static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; static int __init set_ftrace_notrace(char *str) { - strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); + strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); return 1; } __setup("ftrace_notrace=", set_ftrace_notrace); static int __init set_ftrace_filter(char *str) { - strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); + strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); return 1; } __setup("ftrace_filter=", set_ftrace_filter); @@ -3549,7 +3609,7 @@ static const struct file_operations ftrace_filter_fops = { .open = ftrace_filter_open, .read = seq_read, .write = ftrace_filter_write, - .llseek = ftrace_regex_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_regex_release, }; @@ -3557,7 +3617,7 @@ static const struct file_operations ftrace_notrace_fops = { .open = ftrace_notrace_open, .read = seq_read, .write = ftrace_notrace_write, - .llseek = ftrace_regex_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_regex_release, }; @@ -3715,7 +3775,8 @@ out: if (fail) return -EINVAL; - ftrace_graph_filter_enabled = 1; + ftrace_graph_filter_enabled = !!(*idx); + return 0; } @@ -3762,8 +3823,8 @@ static const struct file_operations ftrace_graph_fops = { .open = ftrace_graph_open, .read = seq_read, .write = ftrace_graph_write, + .llseek = ftrace_filter_lseek, .release = ftrace_graph_release, - .llseek = seq_lseek, }; #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ @@ -3970,37 +4031,51 @@ static void ftrace_init_module(struct module *mod, ftrace_process_locs(mod, start, end); } -static int ftrace_module_notify(struct notifier_block *self, - unsigned long val, void *data) +static int ftrace_module_notify_enter(struct notifier_block *self, + unsigned long val, void *data) { struct module *mod = data; - switch (val) { - case MODULE_STATE_COMING: + if (val == MODULE_STATE_COMING) ftrace_init_module(mod, mod->ftrace_callsites, mod->ftrace_callsites + mod->num_ftrace_callsites); - break; - case MODULE_STATE_GOING: + return 0; +} + +static int ftrace_module_notify_exit(struct notifier_block *self, + unsigned long val, void *data) +{ + struct module *mod = data; + + if (val == MODULE_STATE_GOING) ftrace_release_mod(mod); - break; - } return 0; } #else -static int ftrace_module_notify(struct notifier_block *self, - unsigned long val, void *data) +static int ftrace_module_notify_enter(struct notifier_block *self, + unsigned long val, void *data) +{ + return 0; +} +static int ftrace_module_notify_exit(struct notifier_block *self, + unsigned long val, void *data) { return 0; } #endif /* CONFIG_MODULES */ -struct notifier_block ftrace_module_nb = { - .notifier_call = ftrace_module_notify, +struct notifier_block ftrace_module_enter_nb = { + .notifier_call = ftrace_module_notify_enter, .priority = INT_MAX, /* Run before anything that can use kprobes */ }; +struct notifier_block ftrace_module_exit_nb = { + .notifier_call = ftrace_module_notify_exit, + .priority = INT_MIN, /* Run after anything that can remove kprobes */ +}; + extern unsigned long __start_mcount_loc[]; extern unsigned long __stop_mcount_loc[]; @@ -4032,9 +4107,13 @@ void __init ftrace_init(void) __start_mcount_loc, __stop_mcount_loc); - ret = register_module_notifier(&ftrace_module_nb); + ret = register_module_notifier(&ftrace_module_enter_nb); + if (ret) + pr_warning("Failed to register trace ftrace module enter notifier\n"); + + ret = register_module_notifier(&ftrace_module_exit_nb); if (ret) - pr_warning("Failed to register trace ftrace module notifier\n"); + pr_warning("Failed to register trace ftrace module exit notifier\n"); set_ftrace_early_filters(); @@ -4090,14 +4169,12 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, */ preempt_disable_notrace(); trace_recursion_set(TRACE_CONTROL_BIT); - op = rcu_dereference_raw(ftrace_control_list); - while (op != &ftrace_list_end) { - if (!ftrace_function_local_disabled(op) && + do_for_each_ftrace_op(op, ftrace_control_list) { + if (!(op->flags & FTRACE_OPS_FL_STUB) && + !ftrace_function_local_disabled(op) && ftrace_ops_test(op, ip)) op->func(ip, parent_ip, op, regs); - - op = rcu_dereference_raw(op->next); - }; + } while_for_each_ftrace_op(op); trace_recursion_clear(TRACE_CONTROL_BIT); preempt_enable_notrace(); } @@ -4112,27 +4189,26 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ignored, struct pt_regs *regs) { struct ftrace_ops *op; + int bit; if (function_trace_stop) return; - if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT))) + bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); + if (bit < 0) return; - trace_recursion_set(TRACE_INTERNAL_BIT); /* * Some of the ops may be dynamically allocated, * they must be freed after a synchronize_sched(). */ preempt_disable_notrace(); - op = rcu_dereference_raw(ftrace_ops_list); - while (op != &ftrace_list_end) { + do_for_each_ftrace_op(op, ftrace_ops_list) { if (ftrace_ops_test(op, ip)) op->func(ip, parent_ip, op, regs); - op = rcu_dereference_raw(op->next); - }; + } while_for_each_ftrace_op(op); preempt_enable_notrace(); - trace_recursion_clear(TRACE_INTERNAL_BIT); + trace_clear_recursion(bit); } /* @@ -4143,8 +4219,8 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, * Archs are to support both the regs and ftrace_ops at the same time. * If they support ftrace_ops, it is assumed they support regs. * If call backs want to use regs, they must either check for regs - * being NULL, or ARCH_SUPPORTS_FTRACE_SAVE_REGS. - * Note, ARCH_SUPPORT_SAVE_REGS expects a full regs to be saved. + * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. + * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. * An architecture can pass partial regs with ftrace_ops and still * set the ARCH_SUPPORT_FTARCE_OPS. */ @@ -4403,7 +4479,7 @@ static const struct file_operations ftrace_pid_fops = { .open = ftrace_pid_open, .write = ftrace_pid_write, .read = seq_read, - .llseek = seq_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_pid_release, }; @@ -4519,12 +4595,8 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, ftrace_startup_sysctl(); /* we are starting ftrace again */ - if (ftrace_ops_list != &ftrace_list_end) { - if (ftrace_ops_list->next == &ftrace_list_end) - ftrace_trace_function = ftrace_ops_list->func; - else - ftrace_trace_function = ftrace_ops_list_func; - } + if (ftrace_ops_list != &ftrace_list_end) + update_ftrace_function(); } else { /* stopping ftrace calls (just send to ftrace_stub) */ diff --git a/kernel/trace/power-traces.c b/kernel/trace/power-traces.c index f55fcf61b223..1c71382b283d 100644 --- a/kernel/trace/power-traces.c +++ b/kernel/trace/power-traces.c @@ -13,8 +13,5 @@ #define CREATE_TRACE_POINTS #include <trace/events/power.h> -#ifdef EVENT_POWER_TRACING_DEPRECATED -EXPORT_TRACEPOINT_SYMBOL_GPL(power_start); -#endif EXPORT_TRACEPOINT_SYMBOL_GPL(cpu_idle); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index ce8514feedcd..b59aea2c48c2 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3,16 +3,21 @@ * * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com> */ +#include <linux/ftrace_event.h> #include <linux/ring_buffer.h> #include <linux/trace_clock.h> +#include <linux/trace_seq.h> #include <linux/spinlock.h> +#include <linux/irq_work.h> #include <linux/debugfs.h> #include <linux/uaccess.h> #include <linux/hardirq.h> +#include <linux/kthread.h> /* for self test */ #include <linux/kmemcheck.h> #include <linux/module.h> #include <linux/percpu.h> #include <linux/mutex.h> +#include <linux/delay.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/hash.h> @@ -21,7 +26,6 @@ #include <linux/fs.h> #include <asm/local.h> -#include "trace.h" static void update_pages_handler(struct work_struct *work); @@ -177,7 +181,7 @@ void tracing_off_permanent(void) #define RB_MAX_SMALL_DATA (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX) #define RB_EVNT_MIN_SIZE 8U /* two 32bit words */ -#if !defined(CONFIG_64BIT) || defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) +#ifndef CONFIG_HAVE_64BIT_ALIGNED_ACCESS # define RB_FORCE_8BYTE_ALIGNMENT 0 # define RB_ARCH_ALIGNMENT RB_ALIGNMENT #else @@ -185,6 +189,8 @@ void tracing_off_permanent(void) # define RB_ARCH_ALIGNMENT 8U #endif +#define RB_ALIGN_DATA __aligned(RB_ARCH_ALIGNMENT) + /* define RINGBUF_TYPE_DATA for 'case RINGBUF_TYPE_DATA:' */ #define RINGBUF_TYPE_DATA 0 ... RINGBUF_TYPE_DATA_TYPE_LEN_MAX @@ -333,7 +339,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data); struct buffer_data_page { u64 time_stamp; /* page time stamp */ local_t commit; /* write committed index */ - unsigned char data[]; /* data of buffer page */ + unsigned char data[] RB_ALIGN_DATA; /* data of buffer page */ }; /* @@ -441,6 +447,12 @@ int ring_buffer_print_page_header(struct trace_seq *s) return ret; } +struct rb_irq_work { + struct irq_work work; + wait_queue_head_t waiters; + bool waiters_pending; +}; + /* * head_page == tail_page && head == tail then buffer is empty. */ @@ -475,6 +487,8 @@ struct ring_buffer_per_cpu { struct list_head new_pages; /* new pages to add */ struct work_struct update_pages_work; struct completion update_done; + + struct rb_irq_work irq_work; }; struct ring_buffer { @@ -494,6 +508,8 @@ struct ring_buffer { struct notifier_block cpu_notify; #endif u64 (*clock)(void); + + struct rb_irq_work irq_work; }; struct ring_buffer_iter { @@ -505,6 +521,118 @@ struct ring_buffer_iter { u64 read_stamp; }; +/* + * rb_wake_up_waiters - wake up tasks waiting for ring buffer input + * + * Schedules a delayed work to wake up any task that is blocked on the + * ring buffer waiters queue. + */ +static void rb_wake_up_waiters(struct irq_work *work) +{ + struct rb_irq_work *rbwork = container_of(work, struct rb_irq_work, work); + + wake_up_all(&rbwork->waiters); +} + +/** + * ring_buffer_wait - wait for input to the ring buffer + * @buffer: buffer to wait on + * @cpu: the cpu buffer to wait on + * + * If @cpu == RING_BUFFER_ALL_CPUS then the task will wake up as soon + * as data is added to any of the @buffer's cpu buffers. Otherwise + * it will wait for data to be added to a specific cpu buffer. + */ +void ring_buffer_wait(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + DEFINE_WAIT(wait); + struct rb_irq_work *work; + + /* + * Depending on what the caller is waiting for, either any + * data in any cpu buffer, or a specific buffer, put the + * caller on the appropriate wait queue. + */ + if (cpu == RING_BUFFER_ALL_CPUS) + work = &buffer->irq_work; + else { + cpu_buffer = buffer->buffers[cpu]; + work = &cpu_buffer->irq_work; + } + + + prepare_to_wait(&work->waiters, &wait, TASK_INTERRUPTIBLE); + + /* + * The events can happen in critical sections where + * checking a work queue can cause deadlocks. + * After adding a task to the queue, this flag is set + * only to notify events to try to wake up the queue + * using irq_work. + * + * We don't clear it even if the buffer is no longer + * empty. The flag only causes the next event to run + * irq_work to do the work queue wake up. The worse + * that can happen if we race with !trace_empty() is that + * an event will cause an irq_work to try to wake up + * an empty queue. + * + * There's no reason to protect this flag either, as + * the work queue and irq_work logic will do the necessary + * synchronization for the wake ups. The only thing + * that is necessary is that the wake up happens after + * a task has been queued. It's OK for spurious wake ups. + */ + work->waiters_pending = true; + + if ((cpu == RING_BUFFER_ALL_CPUS && ring_buffer_empty(buffer)) || + (cpu != RING_BUFFER_ALL_CPUS && ring_buffer_empty_cpu(buffer, cpu))) + schedule(); + + finish_wait(&work->waiters, &wait); +} + +/** + * ring_buffer_poll_wait - poll on buffer input + * @buffer: buffer to wait on + * @cpu: the cpu buffer to wait on + * @filp: the file descriptor + * @poll_table: The poll descriptor + * + * If @cpu == RING_BUFFER_ALL_CPUS then the task will wake up as soon + * as data is added to any of the @buffer's cpu buffers. Otherwise + * it will wait for data to be added to a specific cpu buffer. + * + * Returns POLLIN | POLLRDNORM if data exists in the buffers, + * zero otherwise. + */ +int ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu, + struct file *filp, poll_table *poll_table) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct rb_irq_work *work; + + if ((cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer)) || + (cpu != RING_BUFFER_ALL_CPUS && !ring_buffer_empty_cpu(buffer, cpu))) + return POLLIN | POLLRDNORM; + + if (cpu == RING_BUFFER_ALL_CPUS) + work = &buffer->irq_work; + else { + cpu_buffer = buffer->buffers[cpu]; + work = &cpu_buffer->irq_work; + } + + work->waiters_pending = true; + poll_wait(filp, &work->waiters, poll_table); + + if ((cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer)) || + (cpu != RING_BUFFER_ALL_CPUS && !ring_buffer_empty_cpu(buffer, cpu))) + return POLLIN | POLLRDNORM; + return 0; +} + /* buffer may be either ring_buffer or ring_buffer_per_cpu */ #define RB_WARN_ON(b, cond) \ ({ \ @@ -1060,6 +1188,8 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int nr_pages, int cpu) cpu_buffer->lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; INIT_WORK(&cpu_buffer->update_pages_work, update_pages_handler); init_completion(&cpu_buffer->update_done); + init_irq_work(&cpu_buffer->irq_work.work, rb_wake_up_waiters); + init_waitqueue_head(&cpu_buffer->irq_work.waiters); bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()), GFP_KERNEL, cpu_to_node(cpu)); @@ -1155,6 +1285,9 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags, buffer->clock = trace_clock_local; buffer->reader_lock_key = key; + init_irq_work(&buffer->irq_work.work, rb_wake_up_waiters); + init_waitqueue_head(&buffer->irq_work.waiters); + /* need at least two pages */ if (nr_pages < 2) nr_pages = 2; @@ -1550,11 +1683,22 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size, if (!cpu_buffer->nr_pages_to_update) continue; - if (cpu_online(cpu)) + /* The update must run on the CPU that is being updated. */ + preempt_disable(); + if (cpu == smp_processor_id() || !cpu_online(cpu)) { + rb_update_pages(cpu_buffer); + cpu_buffer->nr_pages_to_update = 0; + } else { + /* + * Can not disable preemption for schedule_work_on() + * on PREEMPT_RT. + */ + preempt_enable(); schedule_work_on(cpu, &cpu_buffer->update_pages_work); - else - rb_update_pages(cpu_buffer); + preempt_disable(); + } + preempt_enable(); } /* wait for all the updates to complete */ @@ -1592,12 +1736,22 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size, get_online_cpus(); - if (cpu_online(cpu_id)) { + preempt_disable(); + /* The update must run on the CPU that is being updated. */ + if (cpu_id == smp_processor_id() || !cpu_online(cpu_id)) + rb_update_pages(cpu_buffer); + else { + /* + * Can not disable preemption for schedule_work_on() + * on PREEMPT_RT. + */ + preempt_enable(); schedule_work_on(cpu_id, &cpu_buffer->update_pages_work); wait_for_completion(&cpu_buffer->update_done); - } else - rb_update_pages(cpu_buffer); + preempt_disable(); + } + preempt_enable(); cpu_buffer->nr_pages_to_update = 0; put_online_cpus(); @@ -2432,41 +2586,76 @@ rb_reserve_next_event(struct ring_buffer *buffer, #ifdef CONFIG_TRACING -#define TRACE_RECURSIVE_DEPTH 16 +/* + * The lock and unlock are done within a preempt disable section. + * The current_context per_cpu variable can only be modified + * by the current task between lock and unlock. But it can + * be modified more than once via an interrupt. To pass this + * information from the lock to the unlock without having to + * access the 'in_interrupt()' functions again (which do show + * a bit of overhead in something as critical as function tracing, + * we use a bitmask trick. + * + * bit 0 = NMI context + * bit 1 = IRQ context + * bit 2 = SoftIRQ context + * bit 3 = normal context. + * + * This works because this is the order of contexts that can + * preempt other contexts. A SoftIRQ never preempts an IRQ + * context. + * + * When the context is determined, the corresponding bit is + * checked and set (if it was set, then a recursion of that context + * happened). + * + * On unlock, we need to clear this bit. To do so, just subtract + * 1 from the current_context and AND it to itself. + * + * (binary) + * 101 - 1 = 100 + * 101 & 100 = 100 (clearing bit zero) + * + * 1010 - 1 = 1001 + * 1010 & 1001 = 1000 (clearing bit 1) + * + * The least significant bit can be cleared this way, and it + * just so happens that it is the same bit corresponding to + * the current context. + */ +static DEFINE_PER_CPU(unsigned int, current_context); -/* Keep this code out of the fast path cache */ -static noinline void trace_recursive_fail(void) +static __always_inline int trace_recursive_lock(void) { - /* Disable all tracing before we do anything else */ - tracing_off_permanent(); - - printk_once(KERN_WARNING "Tracing recursion: depth[%ld]:" - "HC[%lu]:SC[%lu]:NMI[%lu]\n", - trace_recursion_buffer(), - hardirq_count() >> HARDIRQ_SHIFT, - softirq_count() >> SOFTIRQ_SHIFT, - in_nmi()); - - WARN_ON_ONCE(1); -} + unsigned int val = this_cpu_read(current_context); + int bit; -static inline int trace_recursive_lock(void) -{ - trace_recursion_inc(); + if (in_interrupt()) { + if (in_nmi()) + bit = 0; + else if (in_irq()) + bit = 1; + else + bit = 2; + } else + bit = 3; - if (likely(trace_recursion_buffer() < TRACE_RECURSIVE_DEPTH)) - return 0; + if (unlikely(val & (1 << bit))) + return 1; - trace_recursive_fail(); + val |= (1 << bit); + this_cpu_write(current_context, val); - return -1; + return 0; } -static inline void trace_recursive_unlock(void) +static __always_inline void trace_recursive_unlock(void) { - WARN_ON_ONCE(!trace_recursion_buffer()); + unsigned int val = this_cpu_read(current_context); - trace_recursion_dec(); + val--; + val &= this_cpu_read(current_context); + this_cpu_write(current_context, val); } #else @@ -2574,6 +2763,22 @@ static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer, rb_end_commit(cpu_buffer); } +static __always_inline void +rb_wakeups(struct ring_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer) +{ + if (buffer->irq_work.waiters_pending) { + buffer->irq_work.waiters_pending = false; + /* irq_work_queue() supplies it's own memory barriers */ + irq_work_queue(&buffer->irq_work.work); + } + + if (cpu_buffer->irq_work.waiters_pending) { + cpu_buffer->irq_work.waiters_pending = false; + /* irq_work_queue() supplies it's own memory barriers */ + irq_work_queue(&cpu_buffer->irq_work.work); + } +} + /** * ring_buffer_unlock_commit - commit a reserved * @buffer: The buffer to commit to @@ -2593,6 +2798,8 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer, rb_commit(cpu_buffer, event); + rb_wakeups(buffer, cpu_buffer); + trace_recursive_unlock(); preempt_enable_notrace(); @@ -2765,6 +2972,8 @@ int ring_buffer_write(struct ring_buffer *buffer, rb_commit(cpu_buffer, event); + rb_wakeups(buffer, cpu_buffer); + ret = 0; out: preempt_enable_notrace(); @@ -3067,6 +3276,24 @@ ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu) EXPORT_SYMBOL_GPL(ring_buffer_dropped_events_cpu); /** + * ring_buffer_read_events_cpu - get the number of events successfully read + * @buffer: The ring buffer + * @cpu: The per CPU buffer to get the number of events read + */ +unsigned long +ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpumask_test_cpu(cpu, buffer->cpumask)) + return 0; + + cpu_buffer = buffer->buffers[cpu]; + return cpu_buffer->read; +} +EXPORT_SYMBOL_GPL(ring_buffer_read_events_cpu); + +/** * ring_buffer_entries - get the number of entries in a buffer * @buffer: The ring buffer * @@ -3425,7 +3652,7 @@ static void rb_advance_iter(struct ring_buffer_iter *iter) /* check for end of page padding */ if ((iter->head >= rb_page_size(iter->head_page)) && (iter->head_page != cpu_buffer->commit_page)) - rb_advance_iter(iter); + rb_inc_iter(iter); } static int rb_lost_events(struct ring_buffer_per_cpu *cpu_buffer) @@ -4411,3 +4638,320 @@ static int rb_cpu_notify(struct notifier_block *self, return NOTIFY_OK; } #endif + +#ifdef CONFIG_RING_BUFFER_STARTUP_TEST +/* + * This is a basic integrity check of the ring buffer. + * Late in the boot cycle this test will run when configured in. + * It will kick off a thread per CPU that will go into a loop + * writing to the per cpu ring buffer various sizes of data. + * Some of the data will be large items, some small. + * + * Another thread is created that goes into a spin, sending out + * IPIs to the other CPUs to also write into the ring buffer. + * this is to test the nesting ability of the buffer. + * + * Basic stats are recorded and reported. If something in the + * ring buffer should happen that's not expected, a big warning + * is displayed and all ring buffers are disabled. + */ +static struct task_struct *rb_threads[NR_CPUS] __initdata; + +struct rb_test_data { + struct ring_buffer *buffer; + unsigned long events; + unsigned long bytes_written; + unsigned long bytes_alloc; + unsigned long bytes_dropped; + unsigned long events_nested; + unsigned long bytes_written_nested; + unsigned long bytes_alloc_nested; + unsigned long bytes_dropped_nested; + int min_size_nested; + int max_size_nested; + int max_size; + int min_size; + int cpu; + int cnt; +}; + +static struct rb_test_data rb_data[NR_CPUS] __initdata; + +/* 1 meg per cpu */ +#define RB_TEST_BUFFER_SIZE 1048576 + +static char rb_string[] __initdata = + "abcdefghijklmnopqrstuvwxyz1234567890!@#$%^&*()?+\\" + "?+|:';\",.<>/?abcdefghijklmnopqrstuvwxyz1234567890" + "!@#$%^&*()?+\\?+|:';\",.<>/?abcdefghijklmnopqrstuv"; + +static bool rb_test_started __initdata; + +struct rb_item { + int size; + char str[]; +}; + +static __init int rb_write_something(struct rb_test_data *data, bool nested) +{ + struct ring_buffer_event *event; + struct rb_item *item; + bool started; + int event_len; + int size; + int len; + int cnt; + + /* Have nested writes different that what is written */ + cnt = data->cnt + (nested ? 27 : 0); + + /* Multiply cnt by ~e, to make some unique increment */ + size = (data->cnt * 68 / 25) % (sizeof(rb_string) - 1); + + len = size + sizeof(struct rb_item); + + started = rb_test_started; + /* read rb_test_started before checking buffer enabled */ + smp_rmb(); + + event = ring_buffer_lock_reserve(data->buffer, len); + if (!event) { + /* Ignore dropped events before test starts. */ + if (started) { + if (nested) + data->bytes_dropped += len; + else + data->bytes_dropped_nested += len; + } + return len; + } + + event_len = ring_buffer_event_length(event); + + if (RB_WARN_ON(data->buffer, event_len < len)) + goto out; + + item = ring_buffer_event_data(event); + item->size = size; + memcpy(item->str, rb_string, size); + + if (nested) { + data->bytes_alloc_nested += event_len; + data->bytes_written_nested += len; + data->events_nested++; + if (!data->min_size_nested || len < data->min_size_nested) + data->min_size_nested = len; + if (len > data->max_size_nested) + data->max_size_nested = len; + } else { + data->bytes_alloc += event_len; + data->bytes_written += len; + data->events++; + if (!data->min_size || len < data->min_size) + data->max_size = len; + if (len > data->max_size) + data->max_size = len; + } + + out: + ring_buffer_unlock_commit(data->buffer, event); + + return 0; +} + +static __init int rb_test(void *arg) +{ + struct rb_test_data *data = arg; + + while (!kthread_should_stop()) { + rb_write_something(data, false); + data->cnt++; + + set_current_state(TASK_INTERRUPTIBLE); + /* Now sleep between a min of 100-300us and a max of 1ms */ + usleep_range(((data->cnt % 3) + 1) * 100, 1000); + } + + return 0; +} + +static __init void rb_ipi(void *ignore) +{ + struct rb_test_data *data; + int cpu = smp_processor_id(); + + data = &rb_data[cpu]; + rb_write_something(data, true); +} + +static __init int rb_hammer_test(void *arg) +{ + while (!kthread_should_stop()) { + + /* Send an IPI to all cpus to write data! */ + smp_call_function(rb_ipi, NULL, 1); + /* No sleep, but for non preempt, let others run */ + schedule(); + } + + return 0; +} + +static __init int test_ringbuffer(void) +{ + struct task_struct *rb_hammer; + struct ring_buffer *buffer; + int cpu; + int ret = 0; + + pr_info("Running ring buffer tests...\n"); + + buffer = ring_buffer_alloc(RB_TEST_BUFFER_SIZE, RB_FL_OVERWRITE); + if (WARN_ON(!buffer)) + return 0; + + /* Disable buffer so that threads can't write to it yet */ + ring_buffer_record_off(buffer); + + for_each_online_cpu(cpu) { + rb_data[cpu].buffer = buffer; + rb_data[cpu].cpu = cpu; + rb_data[cpu].cnt = cpu; + rb_threads[cpu] = kthread_create(rb_test, &rb_data[cpu], + "rbtester/%d", cpu); + if (WARN_ON(!rb_threads[cpu])) { + pr_cont("FAILED\n"); + ret = -1; + goto out_free; + } + + kthread_bind(rb_threads[cpu], cpu); + wake_up_process(rb_threads[cpu]); + } + + /* Now create the rb hammer! */ + rb_hammer = kthread_run(rb_hammer_test, NULL, "rbhammer"); + if (WARN_ON(!rb_hammer)) { + pr_cont("FAILED\n"); + ret = -1; + goto out_free; + } + + ring_buffer_record_on(buffer); + /* + * Show buffer is enabled before setting rb_test_started. + * Yes there's a small race window where events could be + * dropped and the thread wont catch it. But when a ring + * buffer gets enabled, there will always be some kind of + * delay before other CPUs see it. Thus, we don't care about + * those dropped events. We care about events dropped after + * the threads see that the buffer is active. + */ + smp_wmb(); + rb_test_started = true; + + set_current_state(TASK_INTERRUPTIBLE); + /* Just run for 10 seconds */; + schedule_timeout(10 * HZ); + + kthread_stop(rb_hammer); + + out_free: + for_each_online_cpu(cpu) { + if (!rb_threads[cpu]) + break; + kthread_stop(rb_threads[cpu]); + } + if (ret) { + ring_buffer_free(buffer); + return ret; + } + + /* Report! */ + pr_info("finished\n"); + for_each_online_cpu(cpu) { + struct ring_buffer_event *event; + struct rb_test_data *data = &rb_data[cpu]; + struct rb_item *item; + unsigned long total_events; + unsigned long total_dropped; + unsigned long total_written; + unsigned long total_alloc; + unsigned long total_read = 0; + unsigned long total_size = 0; + unsigned long total_len = 0; + unsigned long total_lost = 0; + unsigned long lost; + int big_event_size; + int small_event_size; + + ret = -1; + + total_events = data->events + data->events_nested; + total_written = data->bytes_written + data->bytes_written_nested; + total_alloc = data->bytes_alloc + data->bytes_alloc_nested; + total_dropped = data->bytes_dropped + data->bytes_dropped_nested; + + big_event_size = data->max_size + data->max_size_nested; + small_event_size = data->min_size + data->min_size_nested; + + pr_info("CPU %d:\n", cpu); + pr_info(" events: %ld\n", total_events); + pr_info(" dropped bytes: %ld\n", total_dropped); + pr_info(" alloced bytes: %ld\n", total_alloc); + pr_info(" written bytes: %ld\n", total_written); + pr_info(" biggest event: %d\n", big_event_size); + pr_info(" smallest event: %d\n", small_event_size); + + if (RB_WARN_ON(buffer, total_dropped)) + break; + + ret = 0; + + while ((event = ring_buffer_consume(buffer, cpu, NULL, &lost))) { + total_lost += lost; + item = ring_buffer_event_data(event); + total_len += ring_buffer_event_length(event); + total_size += item->size + sizeof(struct rb_item); + if (memcmp(&item->str[0], rb_string, item->size) != 0) { + pr_info("FAILED!\n"); + pr_info("buffer had: %.*s\n", item->size, item->str); + pr_info("expected: %.*s\n", item->size, rb_string); + RB_WARN_ON(buffer, 1); + ret = -1; + break; + } + total_read++; + } + if (ret) + break; + + ret = -1; + + pr_info(" read events: %ld\n", total_read); + pr_info(" lost events: %ld\n", total_lost); + pr_info(" total events: %ld\n", total_lost + total_read); + pr_info(" recorded len bytes: %ld\n", total_len); + pr_info(" recorded size bytes: %ld\n", total_size); + if (total_lost) + pr_info(" With dropped events, record len and size may not match\n" + " alloced and written from above\n"); + if (!total_lost) { + if (RB_WARN_ON(buffer, total_len != total_alloc || + total_size != total_written)) + break; + } + if (RB_WARN_ON(buffer, total_lost + total_read != total_events)) + break; + + ret = 0; + } + if (!ret) + pr_info("Ring buffer PASSED!\n"); + + ring_buffer_free(buffer); + return 0; +} + +late_initcall(test_ringbuffer); +#endif /* CONFIG_RING_BUFFER_STARTUP_TEST */ diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3c13e46d7d24..ae6fa2d1cdf7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1,7 +1,7 @@ /* * ring buffer based function tracer * - * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> + * Copyright (C) 2007-2012 Steven Rostedt <srostedt@redhat.com> * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> * * Originally taken from the RT patch by: @@ -19,7 +19,6 @@ #include <linux/seq_file.h> #include <linux/notifier.h> #include <linux/irqflags.h> -#include <linux/irq_work.h> #include <linux/debugfs.h> #include <linux/pagemap.h> #include <linux/hardirq.h> @@ -39,6 +38,7 @@ #include <linux/poll.h> #include <linux/nmi.h> #include <linux/fs.h> +#include <linux/sched/rt.h> #include "trace.h" #include "trace_output.h" @@ -47,7 +47,7 @@ * On boot up, the ring buffer is set to the minimum size, so that * we do not waste memory on systems that are not using tracing. */ -int ring_buffer_expanded; +bool ring_buffer_expanded; /* * We need to change this state when a selftest is running. @@ -86,14 +86,6 @@ static int dummy_set_flag(u32 old_flags, u32 bit, int set) static DEFINE_PER_CPU(bool, trace_cmdline_save); /* - * When a reader is waiting for data, then this variable is - * set to true. - */ -static bool trace_wakeup_needed; - -static struct irq_work trace_work_wakeup; - -/* * Kill all tracing for good (never come back). * It is initialized to 1 but will turn to zero if the initialization * of the tracer is successful. But that is the only place that sets @@ -129,12 +121,14 @@ static int tracing_set_tracer(const char *buf); static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; static char *default_bootup_tracer; +static bool allocate_snapshot; + static int __init set_cmdline_ftrace(char *str) { - strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); + strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); default_bootup_tracer = bootup_tracer_buf; /* We are using ftrace early, expand it */ - ring_buffer_expanded = 1; + ring_buffer_expanded = true; return 1; } __setup("ftrace=", set_cmdline_ftrace); @@ -155,13 +149,22 @@ static int __init set_ftrace_dump_on_oops(char *str) } __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); +static int __init boot_alloc_snapshot(char *str) +{ + allocate_snapshot = true; + /* We also need the main ring buffer expanded */ + ring_buffer_expanded = true; + return 1; +} +__setup("alloc_snapshot", boot_alloc_snapshot); + static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata; static char *trace_boot_options __initdata; static int __init set_trace_boot_options(char *str) { - strncpy(trace_boot_options_buf, str, MAX_TRACER_SIZE); + strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE); trace_boot_options = trace_boot_options_buf; return 0; } @@ -188,7 +191,7 @@ unsigned long long ns2usecs(cycle_t nsec) */ static struct trace_array global_trace; -static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); +LIST_HEAD(ftrace_trace_arrays); int filter_current_check_discard(struct ring_buffer *buffer, struct ftrace_event_call *call, void *rec, @@ -203,29 +206,15 @@ cycle_t ftrace_now(int cpu) u64 ts; /* Early boot up does not have a buffer yet */ - if (!global_trace.buffer) + if (!global_trace.trace_buffer.buffer) return trace_clock_local(); - ts = ring_buffer_time_stamp(global_trace.buffer, cpu); - ring_buffer_normalize_time_stamp(global_trace.buffer, cpu, &ts); + ts = ring_buffer_time_stamp(global_trace.trace_buffer.buffer, cpu); + ring_buffer_normalize_time_stamp(global_trace.trace_buffer.buffer, cpu, &ts); return ts; } -/* - * The max_tr is used to snapshot the global_trace when a maximum - * latency is reached. Some tracers will use this to store a maximum - * trace while it continues examining live traces. - * - * The buffers for the max_tr are set up the same as the global_trace. - * When a snapshot is taken, the link list of the max_tr is swapped - * with the link list of the global_trace and the buffers are reset for - * the global_trace so the tracing can continue. - */ -static struct trace_array max_tr; - -static DEFINE_PER_CPU(struct trace_array_cpu, max_tr_data); - int tracing_is_enabled(void) { return tracing_is_on(); @@ -248,9 +237,6 @@ static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; /* trace_types holds a link list of available tracers. */ static struct tracer *trace_types __read_mostly; -/* current_trace points to the tracer that is currently active */ -static struct tracer *current_trace __read_mostly; - /* * trace_types_lock is used to protect the trace_types list. */ @@ -284,13 +270,13 @@ static DEFINE_PER_CPU(struct mutex, cpu_access_lock); static inline void trace_access_lock(int cpu) { - if (cpu == TRACE_PIPE_ALL_CPU) { + if (cpu == RING_BUFFER_ALL_CPUS) { /* gain it for accessing the whole ring buffer. */ down_write(&all_cpu_access_lock); } else { /* gain it for accessing a cpu ring buffer. */ - /* Firstly block other trace_access_lock(TRACE_PIPE_ALL_CPU). */ + /* Firstly block other trace_access_lock(RING_BUFFER_ALL_CPUS). */ down_read(&all_cpu_access_lock); /* Secondly block other access to this @cpu ring buffer. */ @@ -300,7 +286,7 @@ static inline void trace_access_lock(int cpu) static inline void trace_access_unlock(int cpu) { - if (cpu == TRACE_PIPE_ALL_CPU) { + if (cpu == RING_BUFFER_ALL_CPUS) { up_write(&all_cpu_access_lock); } else { mutex_unlock(&per_cpu(cpu_access_lock, cpu)); @@ -338,30 +324,11 @@ static inline void trace_access_lock_init(void) #endif -/* trace_wait is a waitqueue for tasks blocked on trace_poll */ -static DECLARE_WAIT_QUEUE_HEAD(trace_wait); - /* trace_flags holds trace_options default values */ unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME | TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | - TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS; - -static int trace_stop_count; -static DEFINE_RAW_SPINLOCK(tracing_start_lock); - -/** - * trace_wake_up - wake up tasks waiting for trace input - * - * Schedules a delayed work to wake up any task that is blocked on the - * trace_wait queue. These is used with trace_poll for tasks polling the - * trace. - */ -static void trace_wake_up(struct irq_work *work) -{ - wake_up_all(&trace_wait); - -} + TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS | TRACE_ITER_FUNCTION; /** * tracing_on - enable tracing buffers @@ -371,8 +338,8 @@ static void trace_wake_up(struct irq_work *work) */ void tracing_on(void) { - if (global_trace.buffer) - ring_buffer_record_on(global_trace.buffer); + if (global_trace.trace_buffer.buffer) + ring_buffer_record_on(global_trace.trace_buffer.buffer); /* * This flag is only looked at when buffers haven't been * allocated yet. We don't really care about the race @@ -384,6 +351,196 @@ void tracing_on(void) EXPORT_SYMBOL_GPL(tracing_on); /** + * __trace_puts - write a constant string into the trace buffer. + * @ip: The address of the caller + * @str: The constant string to write + * @size: The size of the string. + */ +int __trace_puts(unsigned long ip, const char *str, int size) +{ + struct ring_buffer_event *event; + struct ring_buffer *buffer; + struct print_entry *entry; + unsigned long irq_flags; + int alloc; + + alloc = sizeof(*entry) + size + 2; /* possible \n added */ + + local_save_flags(irq_flags); + buffer = global_trace.trace_buffer.buffer; + event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, + irq_flags, preempt_count()); + if (!event) + return 0; + + entry = ring_buffer_event_data(event); + entry->ip = ip; + + memcpy(&entry->buf, str, size); + + /* Add a newline if necessary */ + if (entry->buf[size - 1] != '\n') { + entry->buf[size] = '\n'; + entry->buf[size + 1] = '\0'; + } else + entry->buf[size] = '\0'; + + __buffer_unlock_commit(buffer, event); + + return size; +} +EXPORT_SYMBOL_GPL(__trace_puts); + +/** + * __trace_bputs - write the pointer to a constant string into trace buffer + * @ip: The address of the caller + * @str: The constant string to write to the buffer to + */ +int __trace_bputs(unsigned long ip, const char *str) +{ + struct ring_buffer_event *event; + struct ring_buffer *buffer; + struct bputs_entry *entry; + unsigned long irq_flags; + int size = sizeof(struct bputs_entry); + + local_save_flags(irq_flags); + buffer = global_trace.trace_buffer.buffer; + event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, + irq_flags, preempt_count()); + if (!event) + return 0; + + entry = ring_buffer_event_data(event); + entry->ip = ip; + entry->str = str; + + __buffer_unlock_commit(buffer, event); + + return 1; +} +EXPORT_SYMBOL_GPL(__trace_bputs); + +#ifdef CONFIG_TRACER_SNAPSHOT +/** + * trace_snapshot - take a snapshot of the current buffer. + * + * This causes a swap between the snapshot buffer and the current live + * tracing buffer. You can use this to take snapshots of the live + * trace when some condition is triggered, but continue to trace. + * + * Note, make sure to allocate the snapshot with either + * a tracing_snapshot_alloc(), or by doing it manually + * with: echo 1 > /sys/kernel/debug/tracing/snapshot + * + * If the snapshot buffer is not allocated, it will stop tracing. + * Basically making a permanent snapshot. + */ +void tracing_snapshot(void) +{ + struct trace_array *tr = &global_trace; + struct tracer *tracer = tr->current_trace; + unsigned long flags; + + if (in_nmi()) { + internal_trace_puts("*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n"); + internal_trace_puts("*** snapshot is being ignored ***\n"); + return; + } + + if (!tr->allocated_snapshot) { + internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n"); + internal_trace_puts("*** stopping trace here! ***\n"); + tracing_off(); + return; + } + + /* Note, snapshot can not be used when the tracer uses it */ + if (tracer->use_max_tr) { + internal_trace_puts("*** LATENCY TRACER ACTIVE ***\n"); + internal_trace_puts("*** Can not use snapshot (sorry) ***\n"); + return; + } + + local_irq_save(flags); + update_max_tr(tr, current, smp_processor_id()); + local_irq_restore(flags); +} +EXPORT_SYMBOL_GPL(tracing_snapshot); + +static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf, + struct trace_buffer *size_buf, int cpu_id); +static void set_buffer_entries(struct trace_buffer *buf, unsigned long val); + +static int alloc_snapshot(struct trace_array *tr) +{ + int ret; + + if (!tr->allocated_snapshot) { + + /* allocate spare buffer */ + ret = resize_buffer_duplicate_size(&tr->max_buffer, + &tr->trace_buffer, RING_BUFFER_ALL_CPUS); + if (ret < 0) + return ret; + + tr->allocated_snapshot = true; + } + + return 0; +} + +void free_snapshot(struct trace_array *tr) +{ + /* + * We don't free the ring buffer. instead, resize it because + * The max_tr ring buffer has some state (e.g. ring->clock) and + * we want preserve it. + */ + ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS); + set_buffer_entries(&tr->max_buffer, 1); + tracing_reset_online_cpus(&tr->max_buffer); + tr->allocated_snapshot = false; +} + +/** + * trace_snapshot_alloc - allocate and take a snapshot of the current buffer. + * + * This is similar to trace_snapshot(), but it will allocate the + * snapshot buffer if it isn't already allocated. Use this only + * where it is safe to sleep, as the allocation may sleep. + * + * This causes a swap between the snapshot buffer and the current live + * tracing buffer. You can use this to take snapshots of the live + * trace when some condition is triggered, but continue to trace. + */ +void tracing_snapshot_alloc(void) +{ + struct trace_array *tr = &global_trace; + int ret; + + ret = alloc_snapshot(tr); + if (WARN_ON(ret < 0)) + return; + + tracing_snapshot(); +} +EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); +#else +void tracing_snapshot(void) +{ + WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used"); +} +EXPORT_SYMBOL_GPL(tracing_snapshot); +void tracing_snapshot_alloc(void) +{ + /* Give warning */ + tracing_snapshot(); +} +EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); +#endif /* CONFIG_TRACER_SNAPSHOT */ + +/** * tracing_off - turn off tracing buffers * * This function stops the tracing buffers from recording data. @@ -393,8 +550,8 @@ EXPORT_SYMBOL_GPL(tracing_on); */ void tracing_off(void) { - if (global_trace.buffer) - ring_buffer_record_off(global_trace.buffer); + if (global_trace.trace_buffer.buffer) + ring_buffer_record_off(global_trace.trace_buffer.buffer); /* * This flag is only looked at when buffers haven't been * allocated yet. We don't really care about the race @@ -410,8 +567,8 @@ EXPORT_SYMBOL_GPL(tracing_off); */ int tracing_is_on(void) { - if (global_trace.buffer) - return ring_buffer_record_is_on(global_trace.buffer); + if (global_trace.trace_buffer.buffer) + return ring_buffer_record_is_on(global_trace.trace_buffer.buffer); return !global_trace.buffer_disabled; } EXPORT_SYMBOL_GPL(tracing_is_on); @@ -478,6 +635,7 @@ static const char *trace_options[] = { "disable_on_free", "irq-info", "markers", + "function-trace", NULL }; @@ -489,6 +647,8 @@ static struct { { trace_clock_local, "local", 1 }, { trace_clock_global, "global", 1 }, { trace_clock_counter, "counter", 0 }, + { trace_clock_jiffies, "uptime", 1 }, + { trace_clock, "perf", 1 }, ARCH_TRACE_CLOCKS }; @@ -669,13 +829,14 @@ unsigned long __read_mostly tracing_max_latency; static void __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) { - struct trace_array_cpu *data = tr->data[cpu]; - struct trace_array_cpu *max_data; + struct trace_buffer *trace_buf = &tr->trace_buffer; + struct trace_buffer *max_buf = &tr->max_buffer; + struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu); + struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu); - max_tr.cpu = cpu; - max_tr.time_start = data->preempt_timestamp; + max_buf->cpu = cpu; + max_buf->time_start = data->preempt_timestamp; - max_data = max_tr.data[cpu]; max_data->saved_latency = tracing_max_latency; max_data->critical_start = data->critical_start; max_data->critical_end = data->critical_end; @@ -703,20 +864,24 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) { - struct ring_buffer *buf = tr->buffer; + struct ring_buffer *buf; - if (trace_stop_count) + if (tr->stop_count) return; WARN_ON_ONCE(!irqs_disabled()); - if (!current_trace->use_max_tr) { - WARN_ON_ONCE(1); + + if (!tr->allocated_snapshot) { + /* Only the nop tracer should hit this when disabling */ + WARN_ON_ONCE(tr->current_trace != &nop_trace); return; } + arch_spin_lock(&ftrace_max_lock); - tr->buffer = max_tr.buffer; - max_tr.buffer = buf; + buf = tr->trace_buffer.buffer; + tr->trace_buffer.buffer = tr->max_buffer.buffer; + tr->max_buffer.buffer = buf; __update_max_tr(tr, tsk, cpu); arch_spin_unlock(&ftrace_max_lock); @@ -735,18 +900,19 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) { int ret; - if (trace_stop_count) + if (tr->stop_count) return; WARN_ON_ONCE(!irqs_disabled()); - if (!current_trace->use_max_tr) { - WARN_ON_ONCE(1); + if (!tr->allocated_snapshot) { + /* Only the nop tracer should hit this when disabling */ + WARN_ON_ONCE(tr->current_trace != &nop_trace); return; } arch_spin_lock(&ftrace_max_lock); - ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu); + ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->trace_buffer.buffer, cpu); if (ret == -EBUSY) { /* @@ -755,7 +921,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) * the max trace buffer (no one writes directly to it) * and flag that it failed. */ - trace_array_printk(&max_tr, _THIS_IP_, + trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_, "Failed to swap buffers due to commit in progress\n"); } @@ -768,37 +934,78 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) static void default_wait_pipe(struct trace_iterator *iter) { - DEFINE_WAIT(wait); + /* Iterators are static, they should be filled or empty */ + if (trace_buffer_iter(iter, iter->cpu_file)) + return; + + ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file); +} + +#ifdef CONFIG_FTRACE_STARTUP_TEST +static int run_tracer_selftest(struct tracer *type) +{ + struct trace_array *tr = &global_trace; + struct tracer *saved_tracer = tr->current_trace; + int ret; - prepare_to_wait(&trace_wait, &wait, TASK_INTERRUPTIBLE); + if (!type->selftest || tracing_selftest_disabled) + return 0; /* - * The events can happen in critical sections where - * checking a work queue can cause deadlocks. - * After adding a task to the queue, this flag is set - * only to notify events to try to wake up the queue - * using irq_work. - * - * We don't clear it even if the buffer is no longer - * empty. The flag only causes the next event to run - * irq_work to do the work queue wake up. The worse - * that can happen if we race with !trace_empty() is that - * an event will cause an irq_work to try to wake up - * an empty queue. - * - * There's no reason to protect this flag either, as - * the work queue and irq_work logic will do the necessary - * synchronization for the wake ups. The only thing - * that is necessary is that the wake up happens after - * a task has been queued. It's OK for spurious wake ups. + * Run a selftest on this tracer. + * Here we reset the trace buffer, and set the current + * tracer to be this tracer. The tracer can then run some + * internal tracing to verify that everything is in order. + * If we fail, we do not register this tracer. */ - trace_wakeup_needed = true; + tracing_reset_online_cpus(&tr->trace_buffer); - if (trace_empty(iter)) - schedule(); + tr->current_trace = type; - finish_wait(&trace_wait, &wait); +#ifdef CONFIG_TRACER_MAX_TRACE + if (type->use_max_tr) { + /* If we expanded the buffers, make sure the max is expanded too */ + if (ring_buffer_expanded) + ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size, + RING_BUFFER_ALL_CPUS); + tr->allocated_snapshot = true; + } +#endif + + /* the test is responsible for initializing and enabling */ + pr_info("Testing tracer %s: ", type->name); + ret = type->selftest(type, tr); + /* the test is responsible for resetting too */ + tr->current_trace = saved_tracer; + if (ret) { + printk(KERN_CONT "FAILED!\n"); + /* Add the warning after printing 'FAILED' */ + WARN_ON(1); + return -1; + } + /* Only reset on passing, to avoid touching corrupted buffers */ + tracing_reset_online_cpus(&tr->trace_buffer); + +#ifdef CONFIG_TRACER_MAX_TRACE + if (type->use_max_tr) { + tr->allocated_snapshot = false; + + /* Shrink the max buffer again */ + if (ring_buffer_expanded) + ring_buffer_resize(tr->max_buffer.buffer, 1, + RING_BUFFER_ALL_CPUS); + } +#endif + + printk(KERN_CONT "PASSED\n"); + return 0; } +#else +static inline int run_tracer_selftest(struct tracer *type) +{ + return 0; +} +#endif /* CONFIG_FTRACE_STARTUP_TEST */ /** * register_tracer - register a tracer with the ftrace system. @@ -845,50 +1052,9 @@ int register_tracer(struct tracer *type) if (!type->wait_pipe) type->wait_pipe = default_wait_pipe; - -#ifdef CONFIG_FTRACE_STARTUP_TEST - if (type->selftest && !tracing_selftest_disabled) { - struct tracer *saved_tracer = current_trace; - struct trace_array *tr = &global_trace; - - /* - * Run a selftest on this tracer. - * Here we reset the trace buffer, and set the current - * tracer to be this tracer. The tracer can then run some - * internal tracing to verify that everything is in order. - * If we fail, we do not register this tracer. - */ - tracing_reset_online_cpus(tr); - - current_trace = type; - - /* If we expanded the buffers, make sure the max is expanded too */ - if (ring_buffer_expanded && type->use_max_tr) - ring_buffer_resize(max_tr.buffer, trace_buf_size, - RING_BUFFER_ALL_CPUS); - - /* the test is responsible for initializing and enabling */ - pr_info("Testing tracer %s: ", type->name); - ret = type->selftest(type, tr); - /* the test is responsible for resetting too */ - current_trace = saved_tracer; - if (ret) { - printk(KERN_CONT "FAILED!\n"); - /* Add the warning after printing 'FAILED' */ - WARN_ON(1); - goto out; - } - /* Only reset on passing, to avoid touching corrupted buffers */ - tracing_reset_online_cpus(tr); - - /* Shrink the max buffer again */ - if (ring_buffer_expanded && type->use_max_tr) - ring_buffer_resize(max_tr.buffer, 1, - RING_BUFFER_ALL_CPUS); - - printk(KERN_CONT "PASSED\n"); - } -#endif + ret = run_tracer_selftest(type); + if (ret < 0) + goto out; type->next = trace_types; trace_types = type; @@ -908,7 +1074,7 @@ int register_tracer(struct tracer *type) tracing_set_tracer(type->name); default_bootup_tracer = NULL; /* disable other selftests, since this will break it. */ - tracing_selftest_disabled = 1; + tracing_selftest_disabled = true; #ifdef CONFIG_FTRACE_STARTUP_TEST printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n", type->name); @@ -918,9 +1084,12 @@ int register_tracer(struct tracer *type) return ret; } -void tracing_reset(struct trace_array *tr, int cpu) +void tracing_reset(struct trace_buffer *buf, int cpu) { - struct ring_buffer *buffer = tr->buffer; + struct ring_buffer *buffer = buf->buffer; + + if (!buffer) + return; ring_buffer_record_disable(buffer); @@ -931,17 +1100,20 @@ void tracing_reset(struct trace_array *tr, int cpu) ring_buffer_record_enable(buffer); } -void tracing_reset_online_cpus(struct trace_array *tr) +void tracing_reset_online_cpus(struct trace_buffer *buf) { - struct ring_buffer *buffer = tr->buffer; + struct ring_buffer *buffer = buf->buffer; int cpu; + if (!buffer) + return; + ring_buffer_record_disable(buffer); /* Make sure all commits have finished */ synchronize_sched(); - tr->time_start = ftrace_now(tr->cpu); + buf->time_start = ftrace_now(buf->cpu); for_each_online_cpu(cpu) ring_buffer_reset_cpu(buffer, cpu); @@ -951,12 +1123,21 @@ void tracing_reset_online_cpus(struct trace_array *tr) void tracing_reset_current(int cpu) { - tracing_reset(&global_trace, cpu); + tracing_reset(&global_trace.trace_buffer, cpu); } -void tracing_reset_current_online_cpus(void) +void tracing_reset_all_online_cpus(void) { - tracing_reset_online_cpus(&global_trace); + struct trace_array *tr; + + mutex_lock(&trace_types_lock); + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + tracing_reset_online_cpus(&tr->trace_buffer); +#ifdef CONFIG_TRACER_MAX_TRACE + tracing_reset_online_cpus(&tr->max_buffer); +#endif + } + mutex_unlock(&trace_types_lock); } #define SAVED_CMDLINES 128 @@ -979,7 +1160,7 @@ static void trace_init_cmdlines(void) int is_tracing_stopped(void) { - return trace_stop_count; + return global_trace.stop_count; } /** @@ -1011,12 +1192,12 @@ void tracing_start(void) if (tracing_disabled) return; - raw_spin_lock_irqsave(&tracing_start_lock, flags); - if (--trace_stop_count) { - if (trace_stop_count < 0) { + raw_spin_lock_irqsave(&global_trace.start_lock, flags); + if (--global_trace.stop_count) { + if (global_trace.stop_count < 0) { /* Someone screwed up their debugging */ WARN_ON_ONCE(1); - trace_stop_count = 0; + global_trace.stop_count = 0; } goto out; } @@ -1024,19 +1205,52 @@ void tracing_start(void) /* Prevent the buffers from switching */ arch_spin_lock(&ftrace_max_lock); - buffer = global_trace.buffer; + buffer = global_trace.trace_buffer.buffer; if (buffer) ring_buffer_record_enable(buffer); - buffer = max_tr.buffer; +#ifdef CONFIG_TRACER_MAX_TRACE + buffer = global_trace.max_buffer.buffer; if (buffer) ring_buffer_record_enable(buffer); +#endif arch_spin_unlock(&ftrace_max_lock); ftrace_start(); out: - raw_spin_unlock_irqrestore(&tracing_start_lock, flags); + raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); +} + +static void tracing_start_tr(struct trace_array *tr) +{ + struct ring_buffer *buffer; + unsigned long flags; + + if (tracing_disabled) + return; + + /* If global, we need to also start the max tracer */ + if (tr->flags & TRACE_ARRAY_FL_GLOBAL) + return tracing_start(); + + raw_spin_lock_irqsave(&tr->start_lock, flags); + + if (--tr->stop_count) { + if (tr->stop_count < 0) { + /* Someone screwed up their debugging */ + WARN_ON_ONCE(1); + tr->stop_count = 0; + } + goto out; + } + + buffer = tr->trace_buffer.buffer; + if (buffer) + ring_buffer_record_enable(buffer); + + out: + raw_spin_unlock_irqrestore(&tr->start_lock, flags); } /** @@ -1051,25 +1265,48 @@ void tracing_stop(void) unsigned long flags; ftrace_stop(); - raw_spin_lock_irqsave(&tracing_start_lock, flags); - if (trace_stop_count++) + raw_spin_lock_irqsave(&global_trace.start_lock, flags); + if (global_trace.stop_count++) goto out; /* Prevent the buffers from switching */ arch_spin_lock(&ftrace_max_lock); - buffer = global_trace.buffer; + buffer = global_trace.trace_buffer.buffer; if (buffer) ring_buffer_record_disable(buffer); - buffer = max_tr.buffer; +#ifdef CONFIG_TRACER_MAX_TRACE + buffer = global_trace.max_buffer.buffer; if (buffer) ring_buffer_record_disable(buffer); +#endif arch_spin_unlock(&ftrace_max_lock); out: - raw_spin_unlock_irqrestore(&tracing_start_lock, flags); + raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); +} + +static void tracing_stop_tr(struct trace_array *tr) +{ + struct ring_buffer *buffer; + unsigned long flags; + + /* If global, we need to also stop the max tracer */ + if (tr->flags & TRACE_ARRAY_FL_GLOBAL) + return tracing_stop(); + + raw_spin_lock_irqsave(&tr->start_lock, flags); + if (tr->stop_count++) + goto out; + + buffer = tr->trace_buffer.buffer; + if (buffer) + ring_buffer_record_disable(buffer); + + out: + raw_spin_unlock_irqrestore(&tr->start_lock, flags); } void trace_stop_cmdline_recording(void); @@ -1167,7 +1404,6 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, entry->preempt_count = pc & 0xff; entry->pid = (tsk) ? tsk->pid : 0; - entry->padding = 0; entry->flags = #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | @@ -1203,11 +1439,6 @@ void __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) { __this_cpu_write(trace_cmdline_save, true); - if (trace_wakeup_needed) { - trace_wakeup_needed = false; - /* irq_work_queue() supplies it's own memory barriers */ - irq_work_queue(&trace_work_wakeup); - } ring_buffer_unlock_commit(buffer, event); } @@ -1231,11 +1462,23 @@ void trace_buffer_unlock_commit(struct ring_buffer *buffer, EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit); struct ring_buffer_event * +trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, + struct ftrace_event_file *ftrace_file, + int type, unsigned long len, + unsigned long flags, int pc) +{ + *current_rb = ftrace_file->tr->trace_buffer.buffer; + return trace_buffer_lock_reserve(*current_rb, + type, len, flags, pc); +} +EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve); + +struct ring_buffer_event * trace_current_buffer_lock_reserve(struct ring_buffer **current_rb, int type, unsigned long len, unsigned long flags, int pc) { - *current_rb = global_trace.buffer; + *current_rb = global_trace.trace_buffer.buffer; return trace_buffer_lock_reserve(*current_rb, type, len, flags, pc); } @@ -1274,7 +1517,7 @@ trace_function(struct trace_array *tr, int pc) { struct ftrace_event_call *call = &event_function; - struct ring_buffer *buffer = tr->buffer; + struct ring_buffer *buffer = tr->trace_buffer.buffer; struct ring_buffer_event *event; struct ftrace_entry *entry; @@ -1335,7 +1578,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, */ preempt_disable_notrace(); - use_stack = ++__get_cpu_var(ftrace_stack_reserve); + use_stack = __this_cpu_inc_return(ftrace_stack_reserve); /* * We don't need any atomic variables, just a barrier. * If an interrupt comes in, we don't care, because it would @@ -1389,7 +1632,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, out: /* Again, don't let gcc optimize things here */ barrier(); - __get_cpu_var(ftrace_stack_reserve)--; + __this_cpu_dec(ftrace_stack_reserve); preempt_enable_notrace(); } @@ -1415,13 +1658,14 @@ void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags, void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, int pc) { - __ftrace_trace_stack(tr->buffer, flags, skip, pc, NULL); + __ftrace_trace_stack(tr->trace_buffer.buffer, flags, skip, pc, NULL); } /** * trace_dump_stack - record a stack back trace in the trace buffer + * @skip: Number of functions to skip (helper handlers) */ -void trace_dump_stack(void) +void trace_dump_stack(int skip) { unsigned long flags; @@ -1430,8 +1674,13 @@ void trace_dump_stack(void) local_save_flags(flags); - /* skipping 3 traces, seems to get us at the caller of this function */ - __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count(), NULL); + /* + * Skip 3 more, seems to get us at the caller of + * this function. + */ + skip += 3; + __ftrace_trace_stack(global_trace.trace_buffer.buffer, + flags, skip, preempt_count(), NULL); } static DEFINE_PER_CPU(int, user_stack_count); @@ -1517,7 +1766,6 @@ static struct trace_buffer_struct *trace_percpu_nmi_buffer; static char *get_trace_buf(void) { struct trace_buffer_struct *percpu_buffer; - struct trace_buffer_struct *buffer; /* * If we have allocated per cpu buffers, then we do not @@ -1535,9 +1783,7 @@ static char *get_trace_buf(void) if (!percpu_buffer) return NULL; - buffer = per_cpu_ptr(percpu_buffer, smp_processor_id()); - - return buffer->buffer; + return this_cpu_ptr(&percpu_buffer->buffer[0]); } static int alloc_percpu_trace_buffer(void) @@ -1604,7 +1850,7 @@ void trace_printk_init_buffers(void) * directly here. If the global_trace.buffer is already * allocated here, then this was called by module code. */ - if (global_trace.buffer) + if (global_trace.trace_buffer.buffer) tracing_start_cmdline_record(); } @@ -1664,7 +1910,7 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) local_save_flags(flags); size = sizeof(*entry) + sizeof(u32) * len; - buffer = tr->buffer; + buffer = tr->trace_buffer.buffer; event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, flags, pc); if (!event) @@ -1687,27 +1933,12 @@ out: } EXPORT_SYMBOL_GPL(trace_vbprintk); -int trace_array_printk(struct trace_array *tr, - unsigned long ip, const char *fmt, ...) -{ - int ret; - va_list ap; - - if (!(trace_flags & TRACE_ITER_PRINTK)) - return 0; - - va_start(ap, fmt); - ret = trace_array_vprintk(tr, ip, fmt, ap); - va_end(ap); - return ret; -} - -int trace_array_vprintk(struct trace_array *tr, - unsigned long ip, const char *fmt, va_list args) +static int +__trace_array_vprintk(struct ring_buffer *buffer, + unsigned long ip, const char *fmt, va_list args) { struct ftrace_event_call *call = &event_print; struct ring_buffer_event *event; - struct ring_buffer *buffer; int len = 0, size, pc; struct print_entry *entry; unsigned long flags; @@ -1735,7 +1966,6 @@ int trace_array_vprintk(struct trace_array *tr, local_save_flags(flags); size = sizeof(*entry) + len + 1; - buffer = tr->buffer; event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, flags, pc); if (!event) @@ -1756,6 +1986,42 @@ int trace_array_vprintk(struct trace_array *tr, return len; } +int trace_array_vprintk(struct trace_array *tr, + unsigned long ip, const char *fmt, va_list args) +{ + return __trace_array_vprintk(tr->trace_buffer.buffer, ip, fmt, args); +} + +int trace_array_printk(struct trace_array *tr, + unsigned long ip, const char *fmt, ...) +{ + int ret; + va_list ap; + + if (!(trace_flags & TRACE_ITER_PRINTK)) + return 0; + + va_start(ap, fmt); + ret = trace_array_vprintk(tr, ip, fmt, ap); + va_end(ap); + return ret; +} + +int trace_array_printk_buf(struct ring_buffer *buffer, + unsigned long ip, const char *fmt, ...) +{ + int ret; + va_list ap; + + if (!(trace_flags & TRACE_ITER_PRINTK)) + return 0; + + va_start(ap, fmt); + ret = __trace_array_vprintk(buffer, ip, fmt, ap); + va_end(ap); + return ret; +} + int trace_vprintk(unsigned long ip, const char *fmt, va_list args) { return trace_array_vprintk(&global_trace, ip, fmt, args); @@ -1781,7 +2047,7 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, if (buf_iter) event = ring_buffer_iter_peek(buf_iter, ts); else - event = ring_buffer_peek(iter->tr->buffer, cpu, ts, + event = ring_buffer_peek(iter->trace_buffer->buffer, cpu, ts, lost_events); if (event) { @@ -1796,7 +2062,7 @@ static struct trace_entry * __find_next_entry(struct trace_iterator *iter, int *ent_cpu, unsigned long *missing_events, u64 *ent_ts) { - struct ring_buffer *buffer = iter->tr->buffer; + struct ring_buffer *buffer = iter->trace_buffer->buffer; struct trace_entry *ent, *next = NULL; unsigned long lost_events = 0, next_lost = 0; int cpu_file = iter->cpu_file; @@ -1809,7 +2075,7 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu, * If we are in a per_cpu trace file, don't bother by iterating over * all cpu and peek directly. */ - if (cpu_file > TRACE_PIPE_ALL_CPU) { + if (cpu_file > RING_BUFFER_ALL_CPUS) { if (ring_buffer_empty_cpu(buffer, cpu_file)) return NULL; ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events); @@ -1873,7 +2139,7 @@ void *trace_find_next_entry_inc(struct trace_iterator *iter) static void trace_consume(struct trace_iterator *iter) { - ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts, + ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu, &iter->ts, &iter->lost_events); } @@ -1906,13 +2172,12 @@ static void *s_next(struct seq_file *m, void *v, loff_t *pos) void tracing_iter_reset(struct trace_iterator *iter, int cpu) { - struct trace_array *tr = iter->tr; struct ring_buffer_event *event; struct ring_buffer_iter *buf_iter; unsigned long entries = 0; u64 ts; - tr->data[cpu]->skipped_entries = 0; + per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = 0; buf_iter = trace_buffer_iter(iter, cpu); if (!buf_iter) @@ -1926,13 +2191,13 @@ void tracing_iter_reset(struct trace_iterator *iter, int cpu) * by the timestamp being before the start of the buffer. */ while ((event = ring_buffer_iter_peek(buf_iter, &ts))) { - if (ts >= iter->tr->time_start) + if (ts >= iter->trace_buffer->time_start) break; entries++; ring_buffer_read(buf_iter, NULL); } - tr->data[cpu]->skipped_entries = entries; + per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = entries; } /* @@ -1942,28 +2207,37 @@ void tracing_iter_reset(struct trace_iterator *iter, int cpu) static void *s_start(struct seq_file *m, loff_t *pos) { struct trace_iterator *iter = m->private; - static struct tracer *old_tracer; + struct trace_array *tr = iter->tr; int cpu_file = iter->cpu_file; void *p = NULL; loff_t l = 0; int cpu; - /* copy the tracer to avoid using a global lock all around */ + /* + * copy the tracer to avoid using a global lock all around. + * iter->trace is a copy of current_trace, the pointer to the + * name may be used instead of a strcmp(), as iter->trace->name + * will point to the same string as current_trace->name. + */ mutex_lock(&trace_types_lock); - if (unlikely(old_tracer != current_trace && current_trace)) { - old_tracer = current_trace; - *iter->trace = *current_trace; - } + if (unlikely(tr->current_trace && iter->trace->name != tr->current_trace->name)) + *iter->trace = *tr->current_trace; mutex_unlock(&trace_types_lock); - atomic_inc(&trace_record_cmdline_disabled); +#ifdef CONFIG_TRACER_MAX_TRACE + if (iter->snapshot && iter->trace->use_max_tr) + return ERR_PTR(-EBUSY); +#endif + + if (!iter->snapshot) + atomic_inc(&trace_record_cmdline_disabled); if (*pos != iter->pos) { iter->ent = NULL; iter->cpu = 0; iter->idx = -1; - if (cpu_file == TRACE_PIPE_ALL_CPU) { + if (cpu_file == RING_BUFFER_ALL_CPUS) { for_each_tracing_cpu(cpu) tracing_iter_reset(iter, cpu); } else @@ -1995,13 +2269,21 @@ static void s_stop(struct seq_file *m, void *p) { struct trace_iterator *iter = m->private; - atomic_dec(&trace_record_cmdline_disabled); +#ifdef CONFIG_TRACER_MAX_TRACE + if (iter->snapshot && iter->trace->use_max_tr) + return; +#endif + + if (!iter->snapshot) + atomic_dec(&trace_record_cmdline_disabled); + trace_access_unlock(iter->cpu_file); trace_event_read_unlock(); } static void -get_total_entries(struct trace_array *tr, unsigned long *total, unsigned long *entries) +get_total_entries(struct trace_buffer *buf, + unsigned long *total, unsigned long *entries) { unsigned long count; int cpu; @@ -2010,19 +2292,19 @@ get_total_entries(struct trace_array *tr, unsigned long *total, unsigned long *e *entries = 0; for_each_tracing_cpu(cpu) { - count = ring_buffer_entries_cpu(tr->buffer, cpu); + count = ring_buffer_entries_cpu(buf->buffer, cpu); /* * If this buffer has skipped entries, then we hold all * entries for the trace and we need to ignore the * ones before the time stamp. */ - if (tr->data[cpu]->skipped_entries) { - count -= tr->data[cpu]->skipped_entries; + if (per_cpu_ptr(buf->data, cpu)->skipped_entries) { + count -= per_cpu_ptr(buf->data, cpu)->skipped_entries; /* total is the same as the entries */ *total += count; } else *total += count + - ring_buffer_overrun_cpu(tr->buffer, cpu); + ring_buffer_overrun_cpu(buf->buffer, cpu); *entries += count; } } @@ -2039,27 +2321,27 @@ static void print_lat_help_header(struct seq_file *m) seq_puts(m, "# \\ / ||||| \\ | / \n"); } -static void print_event_info(struct trace_array *tr, struct seq_file *m) +static void print_event_info(struct trace_buffer *buf, struct seq_file *m) { unsigned long total; unsigned long entries; - get_total_entries(tr, &total, &entries); + get_total_entries(buf, &total, &entries); seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n", entries, total, num_online_cpus()); seq_puts(m, "#\n"); } -static void print_func_help_header(struct trace_array *tr, struct seq_file *m) +static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m) { - print_event_info(tr, m); + print_event_info(buf, m); seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); seq_puts(m, "# | | | | |\n"); } -static void print_func_help_header_irq(struct trace_array *tr, struct seq_file *m) +static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m) { - print_event_info(tr, m); + print_event_info(buf, m); seq_puts(m, "# _-----=> irqs-off\n"); seq_puts(m, "# / _----=> need-resched\n"); seq_puts(m, "# | / _---=> hardirq/softirq\n"); @@ -2073,17 +2355,16 @@ void print_trace_header(struct seq_file *m, struct trace_iterator *iter) { unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); - struct trace_array *tr = iter->tr; - struct trace_array_cpu *data = tr->data[tr->cpu]; - struct tracer *type = current_trace; + struct trace_buffer *buf = iter->trace_buffer; + struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu); + struct tracer *type = iter->trace; unsigned long entries; unsigned long total; const char *name = "preemption"; - if (type) - name = type->name; + name = type->name; - get_total_entries(tr, &total, &entries); + get_total_entries(buf, &total, &entries); seq_printf(m, "# %s latency trace v1.1.5 on %s\n", name, UTS_RELEASE); @@ -2094,7 +2375,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter) nsecs_to_usecs(data->saved_latency), entries, total, - tr->cpu, + buf->cpu, #if defined(CONFIG_PREEMPT_NONE) "server", #elif defined(CONFIG_PREEMPT_VOLUNTARY) @@ -2145,7 +2426,7 @@ static void test_cpu_buff_start(struct trace_iterator *iter) if (cpumask_test_cpu(iter->cpu, iter->started)) return; - if (iter->tr->data[iter->cpu]->skipped_entries) + if (per_cpu_ptr(iter->trace_buffer->data, iter->cpu)->skipped_entries) return; cpumask_set_cpu(iter->cpu, iter->started); @@ -2268,14 +2549,14 @@ int trace_empty(struct trace_iterator *iter) int cpu; /* If we are looking at one CPU buffer, only check that one */ - if (iter->cpu_file != TRACE_PIPE_ALL_CPU) { + if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { cpu = iter->cpu_file; buf_iter = trace_buffer_iter(iter, cpu); if (buf_iter) { if (!ring_buffer_iter_empty(buf_iter)) return 0; } else { - if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) + if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu)) return 0; } return 1; @@ -2287,7 +2568,7 @@ int trace_empty(struct trace_iterator *iter) if (!ring_buffer_iter_empty(buf_iter)) return 0; } else { - if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) + if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu)) return 0; } } @@ -2311,6 +2592,11 @@ enum print_line_t print_trace_line(struct trace_iterator *iter) return ret; } + if (iter->ent->type == TRACE_BPUTS && + trace_flags & TRACE_ITER_PRINTK && + trace_flags & TRACE_ITER_PRINTK_MSGONLY) + return trace_print_bputs_msg_only(iter); + if (iter->ent->type == TRACE_BPRINT && trace_flags & TRACE_ITER_PRINTK && trace_flags & TRACE_ITER_PRINTK_MSGONLY) @@ -2365,9 +2651,9 @@ void trace_default_header(struct seq_file *m) } else { if (!(trace_flags & TRACE_ITER_VERBOSE)) { if (trace_flags & TRACE_ITER_IRQ_INFO) - print_func_help_header_irq(iter->tr, m); + print_func_help_header_irq(iter->trace_buffer, m); else - print_func_help_header(iter->tr, m); + print_func_help_header(iter->trace_buffer, m); } } } @@ -2380,6 +2666,50 @@ static void test_ftrace_alive(struct seq_file *m) seq_printf(m, "# MAY BE MISSING FUNCTION EVENTS\n"); } +#ifdef CONFIG_TRACER_MAX_TRACE +static void show_snapshot_main_help(struct seq_file *m) +{ + seq_printf(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n"); + seq_printf(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"); + seq_printf(m, "# Takes a snapshot of the main buffer.\n"); + seq_printf(m, "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate)\n"); + seq_printf(m, "# (Doesn't have to be '2' works with any number that\n"); + seq_printf(m, "# is not a '0' or '1')\n"); +} + +static void show_snapshot_percpu_help(struct seq_file *m) +{ + seq_printf(m, "# echo 0 > snapshot : Invalid for per_cpu snapshot file.\n"); +#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP + seq_printf(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"); + seq_printf(m, "# Takes a snapshot of the main buffer for this cpu.\n"); +#else + seq_printf(m, "# echo 1 > snapshot : Not supported with this kernel.\n"); + seq_printf(m, "# Must use main snapshot file to allocate.\n"); +#endif + seq_printf(m, "# echo 2 > snapshot : Clears this cpu's snapshot buffer (but does not allocate)\n"); + seq_printf(m, "# (Doesn't have to be '2' works with any number that\n"); + seq_printf(m, "# is not a '0' or '1')\n"); +} + +static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) +{ + if (iter->tr->allocated_snapshot) + seq_printf(m, "#\n# * Snapshot is allocated *\n#\n"); + else + seq_printf(m, "#\n# * Snapshot is freed *\n#\n"); + + seq_printf(m, "# Snapshot commands:\n"); + if (iter->cpu_file == RING_BUFFER_ALL_CPUS) + show_snapshot_main_help(m); + else + show_snapshot_percpu_help(m); +} +#else +/* Should never be called */ +static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { } +#endif + static int s_show(struct seq_file *m, void *v) { struct trace_iterator *iter = v; @@ -2391,7 +2721,9 @@ static int s_show(struct seq_file *m, void *v) seq_puts(m, "#\n"); test_ftrace_alive(m); } - if (iter->trace && iter->trace->print_header) + if (iter->snapshot && trace_empty(iter)) + print_snapshot_help(m, iter); + else if (iter->trace && iter->trace->print_header) iter->trace->print_header(m); else trace_default_header(m); @@ -2430,9 +2762,10 @@ static const struct seq_operations tracer_seq_ops = { }; static struct trace_iterator * -__tracing_open(struct inode *inode, struct file *file) +__tracing_open(struct inode *inode, struct file *file, bool snapshot) { - long cpu_file = (long) inode->i_private; + struct trace_cpu *tc = inode->i_private; + struct trace_array *tr = tc->tr; struct trace_iterator *iter; int cpu; @@ -2457,39 +2790,45 @@ __tracing_open(struct inode *inode, struct file *file) if (!iter->trace) goto fail; - if (current_trace) - *iter->trace = *current_trace; + *iter->trace = *tr->current_trace; if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) goto fail; - if (current_trace && current_trace->print_max) - iter->tr = &max_tr; + iter->tr = tr; + +#ifdef CONFIG_TRACER_MAX_TRACE + /* Currently only the top directory has a snapshot */ + if (tr->current_trace->print_max || snapshot) + iter->trace_buffer = &tr->max_buffer; else - iter->tr = &global_trace; +#endif + iter->trace_buffer = &tr->trace_buffer; + iter->snapshot = snapshot; iter->pos = -1; mutex_init(&iter->mutex); - iter->cpu_file = cpu_file; + iter->cpu_file = tc->cpu; /* Notify the tracer early; before we stop tracing. */ if (iter->trace && iter->trace->open) iter->trace->open(iter); /* Annotate start of buffers if we had overruns */ - if (ring_buffer_overruns(iter->tr->buffer)) + if (ring_buffer_overruns(iter->trace_buffer->buffer)) iter->iter_flags |= TRACE_FILE_ANNOTATE; /* Output in nanoseconds only if we are using a clock in nanoseconds. */ if (trace_clocks[trace_clock_id].in_ns) iter->iter_flags |= TRACE_FILE_TIME_IN_NS; - /* stop the trace while dumping */ - tracing_stop(); + /* stop the trace while dumping if we are not opening "snapshot" */ + if (!iter->snapshot) + tracing_stop_tr(tr); - if (iter->cpu_file == TRACE_PIPE_ALL_CPU) { + if (iter->cpu_file == RING_BUFFER_ALL_CPUS) { for_each_tracing_cpu(cpu) { iter->buffer_iter[cpu] = - ring_buffer_read_prepare(iter->tr->buffer, cpu); + ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); } ring_buffer_read_prepare_sync(); for_each_tracing_cpu(cpu) { @@ -2499,12 +2838,14 @@ __tracing_open(struct inode *inode, struct file *file) } else { cpu = iter->cpu_file; iter->buffer_iter[cpu] = - ring_buffer_read_prepare(iter->tr->buffer, cpu); + ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); ring_buffer_read_prepare_sync(); ring_buffer_read_start(iter->buffer_iter[cpu]); tracing_iter_reset(iter, cpu); } + tr->ref++; + mutex_unlock(&trace_types_lock); return iter; @@ -2531,14 +2872,20 @@ static int tracing_release(struct inode *inode, struct file *file) { struct seq_file *m = file->private_data; struct trace_iterator *iter; + struct trace_array *tr; int cpu; if (!(file->f_mode & FMODE_READ)) return 0; iter = m->private; + tr = iter->tr; mutex_lock(&trace_types_lock); + + WARN_ON(!tr->ref); + tr->ref--; + for_each_tracing_cpu(cpu) { if (iter->buffer_iter[cpu]) ring_buffer_read_finish(iter->buffer_iter[cpu]); @@ -2547,8 +2894,9 @@ static int tracing_release(struct inode *inode, struct file *file) if (iter->trace && iter->trace->close) iter->trace->close(iter); - /* reenable tracing if it was previously enabled */ - tracing_start(); + if (!iter->snapshot) + /* reenable tracing if it was previously enabled */ + tracing_start_tr(tr); mutex_unlock(&trace_types_lock); mutex_destroy(&iter->mutex); @@ -2567,16 +2915,17 @@ static int tracing_open(struct inode *inode, struct file *file) /* If this file was open for write, then erase contents */ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { - long cpu = (long) inode->i_private; + struct trace_cpu *tc = inode->i_private; + struct trace_array *tr = tc->tr; - if (cpu == TRACE_PIPE_ALL_CPU) - tracing_reset_online_cpus(&global_trace); + if (tc->cpu == RING_BUFFER_ALL_CPUS) + tracing_reset_online_cpus(&tr->trace_buffer); else - tracing_reset(&global_trace, cpu); + tracing_reset(&tr->trace_buffer, tc->cpu); } if (file->f_mode & FMODE_READ) { - iter = __tracing_open(inode, file); + iter = __tracing_open(inode, file, false); if (IS_ERR(iter)) ret = PTR_ERR(iter); else if (trace_flags & TRACE_ITER_LATENCY_FMT) @@ -2719,8 +3068,9 @@ static ssize_t tracing_cpumask_write(struct file *filp, const char __user *ubuf, size_t count, loff_t *ppos) { - int err, cpu; + struct trace_array *tr = filp->private_data; cpumask_var_t tracing_cpumask_new; + int err, cpu; if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) return -ENOMEM; @@ -2740,13 +3090,13 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, */ if (cpumask_test_cpu(cpu, tracing_cpumask) && !cpumask_test_cpu(cpu, tracing_cpumask_new)) { - atomic_inc(&global_trace.data[cpu]->disabled); - ring_buffer_record_disable_cpu(global_trace.buffer, cpu); + atomic_inc(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled); + ring_buffer_record_disable_cpu(tr->trace_buffer.buffer, cpu); } if (!cpumask_test_cpu(cpu, tracing_cpumask) && cpumask_test_cpu(cpu, tracing_cpumask_new)) { - atomic_dec(&global_trace.data[cpu]->disabled); - ring_buffer_record_enable_cpu(global_trace.buffer, cpu); + atomic_dec(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled); + ring_buffer_record_enable_cpu(tr->trace_buffer.buffer, cpu); } } arch_spin_unlock(&ftrace_max_lock); @@ -2775,12 +3125,13 @@ static const struct file_operations tracing_cpumask_fops = { static int tracing_trace_options_show(struct seq_file *m, void *v) { struct tracer_opt *trace_opts; + struct trace_array *tr = m->private; u32 tracer_flags; int i; mutex_lock(&trace_types_lock); - tracer_flags = current_trace->flags->val; - trace_opts = current_trace->flags->opts; + tracer_flags = tr->current_trace->flags->val; + trace_opts = tr->current_trace->flags->opts; for (i = 0; trace_options[i]; i++) { if (trace_flags & (1 << i)) @@ -2835,11 +3186,25 @@ static int set_tracer_option(struct tracer *trace, char *cmp, int neg) return -EINVAL; } -static void set_tracer_flags(unsigned int mask, int enabled) +/* Some tracers require overwrite to stay enabled */ +int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set) +{ + if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set) + return -1; + + return 0; +} + +int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled) { /* do nothing if flag is already set */ if (!!(trace_flags & mask) == !!enabled) - return; + return 0; + + /* Give the tracer a chance to approve the change */ + if (tr->current_trace->flag_changed) + if (tr->current_trace->flag_changed(tr->current_trace, mask, !!enabled)) + return -EINVAL; if (enabled) trace_flags |= mask; @@ -2849,18 +3214,24 @@ static void set_tracer_flags(unsigned int mask, int enabled) if (mask == TRACE_ITER_RECORD_CMD) trace_event_enable_cmd_record(enabled); - if (mask == TRACE_ITER_OVERWRITE) - ring_buffer_change_overwrite(global_trace.buffer, enabled); + if (mask == TRACE_ITER_OVERWRITE) { + ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled); +#ifdef CONFIG_TRACER_MAX_TRACE + ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled); +#endif + } if (mask == TRACE_ITER_PRINTK) trace_printk_start_stop_comm(enabled); + + return 0; } -static int trace_set_options(char *option) +static int trace_set_options(struct trace_array *tr, char *option) { char *cmp; int neg = 0; - int ret = 0; + int ret = -ENODEV; int i; cmp = strstrip(option); @@ -2870,19 +3241,20 @@ static int trace_set_options(char *option) cmp += 2; } + mutex_lock(&trace_types_lock); + for (i = 0; trace_options[i]; i++) { if (strcmp(cmp, trace_options[i]) == 0) { - set_tracer_flags(1 << i, !neg); + ret = set_tracer_flag(tr, 1 << i, !neg); break; } } /* If no option could be set, test the specific tracer options */ - if (!trace_options[i]) { - mutex_lock(&trace_types_lock); - ret = set_tracer_option(current_trace, cmp, neg); - mutex_unlock(&trace_types_lock); - } + if (!trace_options[i]) + ret = set_tracer_option(tr->current_trace, cmp, neg); + + mutex_unlock(&trace_types_lock); return ret; } @@ -2891,7 +3263,10 @@ static ssize_t tracing_trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { + struct seq_file *m = filp->private_data; + struct trace_array *tr = m->private; char buf[64]; + int ret; if (cnt >= sizeof(buf)) return -EINVAL; @@ -2901,7 +3276,9 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf, buf[cnt] = 0; - trace_set_options(buf); + ret = trace_set_options(tr, buf); + if (ret < 0) + return ret; *ppos += cnt; @@ -2912,7 +3289,8 @@ static int tracing_trace_options_open(struct inode *inode, struct file *file) { if (tracing_disabled) return -ENODEV; - return single_open(file, tracing_trace_options_show, NULL); + + return single_open(file, tracing_trace_options_show, inode->i_private); } static const struct file_operations tracing_iter_fops = { @@ -2925,20 +3303,84 @@ static const struct file_operations tracing_iter_fops = { static const char readme_msg[] = "tracing mini-HOWTO:\n\n" - "# mount -t debugfs nodev /sys/kernel/debug\n\n" - "# cat /sys/kernel/debug/tracing/available_tracers\n" - "wakeup wakeup_rt preemptirqsoff preemptoff irqsoff function nop\n\n" - "# cat /sys/kernel/debug/tracing/current_tracer\n" - "nop\n" - "# echo wakeup > /sys/kernel/debug/tracing/current_tracer\n" - "# cat /sys/kernel/debug/tracing/current_tracer\n" - "wakeup\n" - "# cat /sys/kernel/debug/tracing/trace_options\n" - "noprint-parent nosym-offset nosym-addr noverbose\n" - "# echo print-parent > /sys/kernel/debug/tracing/trace_options\n" - "# echo 1 > /sys/kernel/debug/tracing/tracing_on\n" - "# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt\n" - "# echo 0 > /sys/kernel/debug/tracing/tracing_on\n" + "# echo 0 > tracing_on : quick way to disable tracing\n" + "# echo 1 > tracing_on : quick way to re-enable tracing\n\n" + " Important files:\n" + " trace\t\t\t- The static contents of the buffer\n" + "\t\t\t To clear the buffer write into this file: echo > trace\n" + " trace_pipe\t\t- A consuming read to see the contents of the buffer\n" + " current_tracer\t- function and latency tracers\n" + " available_tracers\t- list of configured tracers for current_tracer\n" + " buffer_size_kb\t- view and modify size of per cpu buffer\n" + " buffer_total_size_kb - view total size of all cpu buffers\n\n" + " trace_clock\t\t-change the clock used to order events\n" + " local: Per cpu clock but may not be synced across CPUs\n" + " global: Synced across CPUs but slows tracing down.\n" + " counter: Not a clock, but just an increment\n" + " uptime: Jiffy counter from time of boot\n" + " perf: Same clock that perf events use\n" +#ifdef CONFIG_X86_64 + " x86-tsc: TSC cycle counter\n" +#endif + "\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n" + " tracing_cpumask\t- Limit which CPUs to trace\n" + " instances\t\t- Make sub-buffers with: mkdir instances/foo\n" + "\t\t\t Remove sub-buffer with rmdir\n" + " trace_options\t\t- Set format or modify how tracing happens\n" + "\t\t\t Disable an option by adding a suffix 'no' to the option name\n" +#ifdef CONFIG_DYNAMIC_FTRACE + "\n available_filter_functions - list of functions that can be filtered on\n" + " set_ftrace_filter\t- echo function name in here to only trace these functions\n" + " accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" + " modules: Can select a group via module\n" + " Format: :mod:<module-name>\n" + " example: echo :mod:ext3 > set_ftrace_filter\n" + " triggers: a command to perform when function is hit\n" + " Format: <function>:<trigger>[:count]\n" + " trigger: traceon, traceoff\n" + " enable_event:<system>:<event>\n" + " disable_event:<system>:<event>\n" +#ifdef CONFIG_STACKTRACE + " stacktrace\n" +#endif +#ifdef CONFIG_TRACER_SNAPSHOT + " snapshot\n" +#endif + " example: echo do_fault:traceoff > set_ftrace_filter\n" + " echo do_trap:traceoff:3 > set_ftrace_filter\n" + " The first one will disable tracing every time do_fault is hit\n" + " The second will disable tracing at most 3 times when do_trap is hit\n" + " The first time do trap is hit and it disables tracing, the counter\n" + " will decrement to 2. If tracing is already disabled, the counter\n" + " will not decrement. It only decrements when the trigger did work\n" + " To remove trigger without count:\n" + " echo '!<function>:<trigger> > set_ftrace_filter\n" + " To remove trigger with a count:\n" + " echo '!<function>:<trigger>:0 > set_ftrace_filter\n" + " set_ftrace_notrace\t- echo function name in here to never trace.\n" + " accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" + " modules: Can select a group via module command :mod:\n" + " Does not accept triggers\n" +#endif /* CONFIG_DYNAMIC_FTRACE */ +#ifdef CONFIG_FUNCTION_TRACER + " set_ftrace_pid\t- Write pid(s) to only function trace those pids (function)\n" +#endif +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + " set_graph_function\t- Trace the nested calls of a function (function_graph)\n" + " max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n" +#endif +#ifdef CONFIG_TRACER_SNAPSHOT + "\n snapshot\t\t- Like 'trace' but shows the content of the static snapshot buffer\n" + "\t\t\t Read the contents for more information\n" +#endif +#ifdef CONFIG_STACKTRACE + " stack_trace\t\t- Shows the max stack trace when active\n" + " stack_max_size\t- Shows current max stack size that was traced\n" + "\t\t\t Write into this file to reset the max size (trigger a new trace)\n" +#ifdef CONFIG_DYNAMIC_FTRACE + " stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace traces\n" +#endif +#endif /* CONFIG_STACKTRACE */ ; static ssize_t @@ -3010,14 +3452,12 @@ static ssize_t tracing_set_trace_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { + struct trace_array *tr = filp->private_data; char buf[MAX_TRACER_SIZE+2]; int r; mutex_lock(&trace_types_lock); - if (current_trace) - r = sprintf(buf, "%s\n", current_trace->name); - else - r = sprintf(buf, "\n"); + r = sprintf(buf, "%s\n", tr->current_trace->name); mutex_unlock(&trace_types_lock); return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); @@ -3025,43 +3465,48 @@ tracing_set_trace_read(struct file *filp, char __user *ubuf, int tracer_init(struct tracer *t, struct trace_array *tr) { - tracing_reset_online_cpus(tr); + tracing_reset_online_cpus(&tr->trace_buffer); return t->init(tr); } -static void set_buffer_entries(struct trace_array *tr, unsigned long val) +static void set_buffer_entries(struct trace_buffer *buf, unsigned long val) { int cpu; + for_each_tracing_cpu(cpu) - tr->data[cpu]->entries = val; + per_cpu_ptr(buf->data, cpu)->entries = val; } +#ifdef CONFIG_TRACER_MAX_TRACE /* resize @tr's buffer to the size of @size_tr's entries */ -static int resize_buffer_duplicate_size(struct trace_array *tr, - struct trace_array *size_tr, int cpu_id) +static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf, + struct trace_buffer *size_buf, int cpu_id) { int cpu, ret = 0; if (cpu_id == RING_BUFFER_ALL_CPUS) { for_each_tracing_cpu(cpu) { - ret = ring_buffer_resize(tr->buffer, - size_tr->data[cpu]->entries, cpu); + ret = ring_buffer_resize(trace_buf->buffer, + per_cpu_ptr(size_buf->data, cpu)->entries, cpu); if (ret < 0) break; - tr->data[cpu]->entries = size_tr->data[cpu]->entries; + per_cpu_ptr(trace_buf->data, cpu)->entries = + per_cpu_ptr(size_buf->data, cpu)->entries; } } else { - ret = ring_buffer_resize(tr->buffer, - size_tr->data[cpu_id]->entries, cpu_id); + ret = ring_buffer_resize(trace_buf->buffer, + per_cpu_ptr(size_buf->data, cpu_id)->entries, cpu_id); if (ret == 0) - tr->data[cpu_id]->entries = - size_tr->data[cpu_id]->entries; + per_cpu_ptr(trace_buf->data, cpu_id)->entries = + per_cpu_ptr(size_buf->data, cpu_id)->entries; } return ret; } +#endif /* CONFIG_TRACER_MAX_TRACE */ -static int __tracing_resize_ring_buffer(unsigned long size, int cpu) +static int __tracing_resize_ring_buffer(struct trace_array *tr, + unsigned long size, int cpu) { int ret; @@ -3070,23 +3515,25 @@ static int __tracing_resize_ring_buffer(unsigned long size, int cpu) * we use the size that was given, and we can forget about * expanding it later. */ - ring_buffer_expanded = 1; + ring_buffer_expanded = true; /* May be called before buffers are initialized */ - if (!global_trace.buffer) + if (!tr->trace_buffer.buffer) return 0; - ret = ring_buffer_resize(global_trace.buffer, size, cpu); + ret = ring_buffer_resize(tr->trace_buffer.buffer, size, cpu); if (ret < 0) return ret; - if (!current_trace->use_max_tr) +#ifdef CONFIG_TRACER_MAX_TRACE + if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL) || + !tr->current_trace->use_max_tr) goto out; - ret = ring_buffer_resize(max_tr.buffer, size, cpu); + ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu); if (ret < 0) { - int r = resize_buffer_duplicate_size(&global_trace, - &global_trace, cpu); + int r = resize_buffer_duplicate_size(&tr->trace_buffer, + &tr->trace_buffer, cpu); if (r < 0) { /* * AARGH! We are left with different @@ -3109,20 +3556,23 @@ static int __tracing_resize_ring_buffer(unsigned long size, int cpu) } if (cpu == RING_BUFFER_ALL_CPUS) - set_buffer_entries(&max_tr, size); + set_buffer_entries(&tr->max_buffer, size); else - max_tr.data[cpu]->entries = size; + per_cpu_ptr(tr->max_buffer.data, cpu)->entries = size; out: +#endif /* CONFIG_TRACER_MAX_TRACE */ + if (cpu == RING_BUFFER_ALL_CPUS) - set_buffer_entries(&global_trace, size); + set_buffer_entries(&tr->trace_buffer, size); else - global_trace.data[cpu]->entries = size; + per_cpu_ptr(tr->trace_buffer.data, cpu)->entries = size; return ret; } -static ssize_t tracing_resize_ring_buffer(unsigned long size, int cpu_id) +static ssize_t tracing_resize_ring_buffer(struct trace_array *tr, + unsigned long size, int cpu_id) { int ret = size; @@ -3136,7 +3586,7 @@ static ssize_t tracing_resize_ring_buffer(unsigned long size, int cpu_id) } } - ret = __tracing_resize_ring_buffer(size, cpu_id); + ret = __tracing_resize_ring_buffer(tr, size, cpu_id); if (ret < 0) ret = -ENOMEM; @@ -3163,7 +3613,7 @@ int tracing_update_buffers(void) mutex_lock(&trace_types_lock); if (!ring_buffer_expanded) - ret = __tracing_resize_ring_buffer(trace_buf_size, + ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size, RING_BUFFER_ALL_CPUS); mutex_unlock(&trace_types_lock); @@ -3173,7 +3623,7 @@ int tracing_update_buffers(void) struct trace_option_dentry; static struct trace_option_dentry * -create_trace_option_files(struct tracer *tracer); +create_trace_option_files(struct trace_array *tr, struct tracer *tracer); static void destroy_trace_option_files(struct trace_option_dentry *topts); @@ -3183,12 +3633,15 @@ static int tracing_set_tracer(const char *buf) static struct trace_option_dentry *topts; struct trace_array *tr = &global_trace; struct tracer *t; +#ifdef CONFIG_TRACER_MAX_TRACE + bool had_max_tr; +#endif int ret = 0; mutex_lock(&trace_types_lock); if (!ring_buffer_expanded) { - ret = __tracing_resize_ring_buffer(trace_buf_size, + ret = __tracing_resize_ring_buffer(tr, trace_buf_size, RING_BUFFER_ALL_CPUS); if (ret < 0) goto out; @@ -3203,33 +3656,45 @@ static int tracing_set_tracer(const char *buf) ret = -EINVAL; goto out; } - if (t == current_trace) + if (t == tr->current_trace) goto out; trace_branch_disable(); - if (current_trace && current_trace->reset) - current_trace->reset(tr); - if (current_trace && current_trace->use_max_tr) { + + tr->current_trace->enabled = false; + + if (tr->current_trace->reset) + tr->current_trace->reset(tr); + + /* Current trace needs to be nop_trace before synchronize_sched */ + tr->current_trace = &nop_trace; + +#ifdef CONFIG_TRACER_MAX_TRACE + had_max_tr = tr->allocated_snapshot; + + if (had_max_tr && !t->use_max_tr) { /* - * We don't free the ring buffer. instead, resize it because - * The max_tr ring buffer has some state (e.g. ring->clock) and - * we want preserve it. + * We need to make sure that the update_max_tr sees that + * current_trace changed to nop_trace to keep it from + * swapping the buffers after we resize it. + * The update_max_tr is called from interrupts disabled + * so a synchronized_sched() is sufficient. */ - ring_buffer_resize(max_tr.buffer, 1, RING_BUFFER_ALL_CPUS); - set_buffer_entries(&max_tr, 1); + synchronize_sched(); + free_snapshot(tr); } +#endif destroy_trace_option_files(topts); - current_trace = &nop_trace; + topts = create_trace_option_files(tr, t); - topts = create_trace_option_files(t); - if (t->use_max_tr) { - /* we need to make per cpu buffer sizes equivalent */ - ret = resize_buffer_duplicate_size(&max_tr, &global_trace, - RING_BUFFER_ALL_CPUS); +#ifdef CONFIG_TRACER_MAX_TRACE + if (t->use_max_tr && !had_max_tr) { + ret = alloc_snapshot(tr); if (ret < 0) goto out; } +#endif if (t->init) { ret = tracer_init(t, tr); @@ -3237,7 +3702,8 @@ static int tracing_set_tracer(const char *buf) goto out; } - current_trace = t; + tr->current_trace = t; + tr->current_trace->enabled = true; trace_branch_enable(tr); out: mutex_unlock(&trace_types_lock); @@ -3311,7 +3777,8 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf, static int tracing_open_pipe(struct inode *inode, struct file *filp) { - long cpu_file = (long) inode->i_private; + struct trace_cpu *tc = inode->i_private; + struct trace_array *tr = tc->tr; struct trace_iterator *iter; int ret = 0; @@ -3336,8 +3803,7 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) ret = -ENOMEM; goto fail; } - if (current_trace) - *iter->trace = *current_trace; + *iter->trace = *tr->current_trace; if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { ret = -ENOMEM; @@ -3354,8 +3820,9 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) if (trace_clocks[trace_clock_id].in_ns) iter->iter_flags |= TRACE_FILE_TIME_IN_NS; - iter->cpu_file = cpu_file; - iter->tr = &global_trace; + iter->cpu_file = tc->cpu; + iter->tr = tc->tr; + iter->trace_buffer = &tc->tr->trace_buffer; mutex_init(&iter->mutex); filp->private_data = iter; @@ -3394,24 +3861,28 @@ static int tracing_release_pipe(struct inode *inode, struct file *file) } static unsigned int -tracing_poll_pipe(struct file *filp, poll_table *poll_table) +trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table) { - struct trace_iterator *iter = filp->private_data; + /* Iterators are static, they should be filled or empty */ + if (trace_buffer_iter(iter, iter->cpu_file)) + return POLLIN | POLLRDNORM; - if (trace_flags & TRACE_ITER_BLOCK) { + if (trace_flags & TRACE_ITER_BLOCK) /* * Always select as readable when in blocking mode */ return POLLIN | POLLRDNORM; - } else { - if (!trace_empty(iter)) - return POLLIN | POLLRDNORM; - poll_wait(filp, &trace_wait, poll_table); - if (!trace_empty(iter)) - return POLLIN | POLLRDNORM; + else + return ring_buffer_poll_wait(iter->trace_buffer->buffer, iter->cpu_file, + filp, poll_table); +} - return 0; - } +static unsigned int +tracing_poll_pipe(struct file *filp, poll_table *poll_table) +{ + struct trace_iterator *iter = filp->private_data; + + return trace_poll(iter, filp, poll_table); } /* @@ -3477,7 +3948,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_iterator *iter = filp->private_data; - static struct tracer *old_tracer; + struct trace_array *tr = iter->tr; ssize_t sret; /* return any leftover data */ @@ -3489,10 +3960,8 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, /* copy the tracer to avoid using a global lock all around */ mutex_lock(&trace_types_lock); - if (unlikely(old_tracer != current_trace && current_trace)) { - old_tracer = current_trace; - *iter->trace = *current_trace; - } + if (unlikely(iter->trace->name != tr->current_trace->name)) + *iter->trace = *tr->current_trace; mutex_unlock(&trace_types_lock); /* @@ -3648,7 +4117,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp, .ops = &tracing_pipe_buf_ops, .spd_release = tracing_spd_release_pipe, }; - static struct tracer *old_tracer; + struct trace_array *tr = iter->tr; ssize_t ret; size_t rem; unsigned int i; @@ -3658,10 +4127,8 @@ static ssize_t tracing_splice_read_pipe(struct file *filp, /* copy the tracer to avoid using a global lock all around */ mutex_lock(&trace_types_lock); - if (unlikely(old_tracer != current_trace && current_trace)) { - old_tracer = current_trace; - *iter->trace = *current_trace; - } + if (unlikely(iter->trace->name != tr->current_trace->name)) + *iter->trace = *tr->current_trace; mutex_unlock(&trace_types_lock); mutex_lock(&iter->mutex); @@ -3723,43 +4190,19 @@ out_err: goto out; } -struct ftrace_entries_info { - struct trace_array *tr; - int cpu; -}; - -static int tracing_entries_open(struct inode *inode, struct file *filp) -{ - struct ftrace_entries_info *info; - - if (tracing_disabled) - return -ENODEV; - - info = kzalloc(sizeof(*info), GFP_KERNEL); - if (!info) - return -ENOMEM; - - info->tr = &global_trace; - info->cpu = (unsigned long)inode->i_private; - - filp->private_data = info; - - return 0; -} - static ssize_t tracing_entries_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { - struct ftrace_entries_info *info = filp->private_data; - struct trace_array *tr = info->tr; + struct trace_cpu *tc = filp->private_data; + struct trace_array *tr = tc->tr; char buf[64]; int r = 0; ssize_t ret; mutex_lock(&trace_types_lock); - if (info->cpu == RING_BUFFER_ALL_CPUS) { + if (tc->cpu == RING_BUFFER_ALL_CPUS) { int cpu, buf_size_same; unsigned long size; @@ -3769,8 +4212,8 @@ tracing_entries_read(struct file *filp, char __user *ubuf, for_each_tracing_cpu(cpu) { /* fill in the size from first enabled cpu */ if (size == 0) - size = tr->data[cpu]->entries; - if (size != tr->data[cpu]->entries) { + size = per_cpu_ptr(tr->trace_buffer.data, cpu)->entries; + if (size != per_cpu_ptr(tr->trace_buffer.data, cpu)->entries) { buf_size_same = 0; break; } @@ -3786,7 +4229,7 @@ tracing_entries_read(struct file *filp, char __user *ubuf, } else r = sprintf(buf, "X\n"); } else - r = sprintf(buf, "%lu\n", tr->data[info->cpu]->entries >> 10); + r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, tc->cpu)->entries >> 10); mutex_unlock(&trace_types_lock); @@ -3798,7 +4241,7 @@ static ssize_t tracing_entries_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - struct ftrace_entries_info *info = filp->private_data; + struct trace_cpu *tc = filp->private_data; unsigned long val; int ret; @@ -3813,7 +4256,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, /* value is in KB */ val <<= 10; - ret = tracing_resize_ring_buffer(val, info->cpu); + ret = tracing_resize_ring_buffer(tc->tr, val, tc->cpu); if (ret < 0) return ret; @@ -3822,16 +4265,6 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, return cnt; } -static int -tracing_entries_release(struct inode *inode, struct file *filp) -{ - struct ftrace_entries_info *info = filp->private_data; - - kfree(info); - - return 0; -} - static ssize_t tracing_total_entries_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) @@ -3843,7 +4276,7 @@ tracing_total_entries_read(struct file *filp, char __user *ubuf, mutex_lock(&trace_types_lock); for_each_tracing_cpu(cpu) { - size += tr->data[cpu]->entries >> 10; + size += per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10; if (!ring_buffer_expanded) expanded_size += trace_buf_size >> 10; } @@ -3873,11 +4306,13 @@ tracing_free_buffer_write(struct file *filp, const char __user *ubuf, static int tracing_free_buffer_release(struct inode *inode, struct file *filp) { + struct trace_array *tr = inode->i_private; + /* disable tracing ? */ if (trace_flags & TRACE_ITER_STOP_ON_FREE) tracing_off(); /* resize the ring buffer to 0 */ - tracing_resize_ring_buffer(0, RING_BUFFER_ALL_CPUS); + tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS); return 0; } @@ -3946,7 +4381,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, local_save_flags(irq_flags); size = sizeof(*entry) + cnt + 2; /* possible \n added */ - buffer = global_trace.buffer; + buffer = global_trace.trace_buffer.buffer; event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, irq_flags, preempt_count()); if (!event) { @@ -3988,13 +4423,14 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, static int tracing_clock_show(struct seq_file *m, void *v) { + struct trace_array *tr = m->private; int i; for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) seq_printf(m, "%s%s%s%s", i ? " " : "", - i == trace_clock_id ? "[" : "", trace_clocks[i].name, - i == trace_clock_id ? "]" : ""); + i == tr->clock_id ? "[" : "", trace_clocks[i].name, + i == tr->clock_id ? "]" : ""); seq_putc(m, '\n'); return 0; @@ -4003,6 +4439,8 @@ static int tracing_clock_show(struct seq_file *m, void *v) static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *fpos) { + struct seq_file *m = filp->private_data; + struct trace_array *tr = m->private; char buf[64]; const char *clockstr; int i; @@ -4024,21 +4462,23 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, if (i == ARRAY_SIZE(trace_clocks)) return -EINVAL; - trace_clock_id = i; - mutex_lock(&trace_types_lock); - ring_buffer_set_clock(global_trace.buffer, trace_clocks[i].func); - if (max_tr.buffer) - ring_buffer_set_clock(max_tr.buffer, trace_clocks[i].func); + tr->clock_id = i; + + ring_buffer_set_clock(tr->trace_buffer.buffer, trace_clocks[i].func); /* * New clock may not be consistent with the previous clock. * Reset the buffer so that it doesn't have incomparable timestamps. */ - tracing_reset_online_cpus(&global_trace); - if (max_tr.buffer) - tracing_reset_online_cpus(&max_tr); + tracing_reset_online_cpus(&global_trace.trace_buffer); + +#ifdef CONFIG_TRACER_MAX_TRACE + if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer) + ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func); + tracing_reset_online_cpus(&global_trace.max_buffer); +#endif mutex_unlock(&trace_types_lock); @@ -4051,9 +4491,169 @@ static int tracing_clock_open(struct inode *inode, struct file *file) { if (tracing_disabled) return -ENODEV; - return single_open(file, tracing_clock_show, NULL); + + return single_open(file, tracing_clock_show, inode->i_private); } +struct ftrace_buffer_info { + struct trace_iterator iter; + void *spare; + unsigned int read; +}; + +#ifdef CONFIG_TRACER_SNAPSHOT +static int tracing_snapshot_open(struct inode *inode, struct file *file) +{ + struct trace_cpu *tc = inode->i_private; + struct trace_iterator *iter; + struct seq_file *m; + int ret = 0; + + if (file->f_mode & FMODE_READ) { + iter = __tracing_open(inode, file, true); + if (IS_ERR(iter)) + ret = PTR_ERR(iter); + } else { + /* Writes still need the seq_file to hold the private data */ + m = kzalloc(sizeof(*m), GFP_KERNEL); + if (!m) + return -ENOMEM; + iter = kzalloc(sizeof(*iter), GFP_KERNEL); + if (!iter) { + kfree(m); + return -ENOMEM; + } + iter->tr = tc->tr; + iter->trace_buffer = &tc->tr->max_buffer; + iter->cpu_file = tc->cpu; + m->private = iter; + file->private_data = m; + } + + return ret; +} + +static ssize_t +tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, + loff_t *ppos) +{ + struct seq_file *m = filp->private_data; + struct trace_iterator *iter = m->private; + struct trace_array *tr = iter->tr; + unsigned long val; + int ret; + + ret = tracing_update_buffers(); + if (ret < 0) + return ret; + + ret = kstrtoul_from_user(ubuf, cnt, 10, &val); + if (ret) + return ret; + + mutex_lock(&trace_types_lock); + + if (tr->current_trace->use_max_tr) { + ret = -EBUSY; + goto out; + } + + switch (val) { + case 0: + if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { + ret = -EINVAL; + break; + } + if (tr->allocated_snapshot) + free_snapshot(tr); + break; + case 1: +/* Only allow per-cpu swap if the ring buffer supports it */ +#ifndef CONFIG_RING_BUFFER_ALLOW_SWAP + if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { + ret = -EINVAL; + break; + } +#endif + if (!tr->allocated_snapshot) { + ret = alloc_snapshot(tr); + if (ret < 0) + break; + } + local_irq_disable(); + /* Now, we're going to swap */ + if (iter->cpu_file == RING_BUFFER_ALL_CPUS) + update_max_tr(tr, current, smp_processor_id()); + else + update_max_tr_single(tr, current, iter->cpu_file); + local_irq_enable(); + break; + default: + if (tr->allocated_snapshot) { + if (iter->cpu_file == RING_BUFFER_ALL_CPUS) + tracing_reset_online_cpus(&tr->max_buffer); + else + tracing_reset(&tr->max_buffer, iter->cpu_file); + } + break; + } + + if (ret >= 0) { + *ppos += cnt; + ret = cnt; + } +out: + mutex_unlock(&trace_types_lock); + return ret; +} + +static int tracing_snapshot_release(struct inode *inode, struct file *file) +{ + struct seq_file *m = file->private_data; + + if (file->f_mode & FMODE_READ) + return tracing_release(inode, file); + + /* If write only, the seq_file is just a stub */ + if (m) + kfree(m->private); + kfree(m); + + return 0; +} + +static int tracing_buffers_open(struct inode *inode, struct file *filp); +static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *ppos); +static int tracing_buffers_release(struct inode *inode, struct file *file); +static ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, unsigned int flags); + +static int snapshot_raw_open(struct inode *inode, struct file *filp) +{ + struct ftrace_buffer_info *info; + int ret; + + ret = tracing_buffers_open(inode, filp); + if (ret < 0) + return ret; + + info = filp->private_data; + + if (info->iter.trace->use_max_tr) { + tracing_buffers_release(inode, filp); + return -EBUSY; + } + + info->iter.snapshot = true; + info->iter.trace_buffer = &info->iter.tr->max_buffer; + + return ret; +} + +#endif /* CONFIG_TRACER_SNAPSHOT */ + + static const struct file_operations tracing_max_lat_fops = { .open = tracing_open_generic, .read = tracing_max_lat_read, @@ -4078,10 +4678,9 @@ static const struct file_operations tracing_pipe_fops = { }; static const struct file_operations tracing_entries_fops = { - .open = tracing_entries_open, + .open = tracing_open_generic, .read = tracing_entries_read, .write = tracing_entries_write, - .release = tracing_entries_release, .llseek = generic_file_llseek, }; @@ -4110,16 +4709,29 @@ static const struct file_operations trace_clock_fops = { .write = tracing_clock_write, }; -struct ftrace_buffer_info { - struct trace_array *tr; - void *spare; - int cpu; - unsigned int read; +#ifdef CONFIG_TRACER_SNAPSHOT +static const struct file_operations snapshot_fops = { + .open = tracing_snapshot_open, + .read = seq_read, + .write = tracing_snapshot_write, + .llseek = tracing_seek, + .release = tracing_snapshot_release, }; +static const struct file_operations snapshot_raw_fops = { + .open = snapshot_raw_open, + .read = tracing_buffers_read, + .release = tracing_buffers_release, + .splice_read = tracing_buffers_splice_read, + .llseek = no_llseek, +}; + +#endif /* CONFIG_TRACER_SNAPSHOT */ + static int tracing_buffers_open(struct inode *inode, struct file *filp) { - int cpu = (int)(long)inode->i_private; + struct trace_cpu *tc = inode->i_private; + struct trace_array *tr = tc->tr; struct ftrace_buffer_info *info; if (tracing_disabled) @@ -4129,72 +4741,131 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp) if (!info) return -ENOMEM; - info->tr = &global_trace; - info->cpu = cpu; - info->spare = NULL; + mutex_lock(&trace_types_lock); + + tr->ref++; + + info->iter.tr = tr; + info->iter.cpu_file = tc->cpu; + info->iter.trace = tr->current_trace; + info->iter.trace_buffer = &tr->trace_buffer; + info->spare = NULL; /* Force reading ring buffer for first read */ - info->read = (unsigned int)-1; + info->read = (unsigned int)-1; filp->private_data = info; + mutex_unlock(&trace_types_lock); + return nonseekable_open(inode, filp); } +static unsigned int +tracing_buffers_poll(struct file *filp, poll_table *poll_table) +{ + struct ftrace_buffer_info *info = filp->private_data; + struct trace_iterator *iter = &info->iter; + + return trace_poll(iter, filp, poll_table); +} + static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, size_t count, loff_t *ppos) { struct ftrace_buffer_info *info = filp->private_data; + struct trace_iterator *iter = &info->iter; ssize_t ret; - size_t size; + ssize_t size; if (!count) return 0; + mutex_lock(&trace_types_lock); + +#ifdef CONFIG_TRACER_MAX_TRACE + if (iter->snapshot && iter->tr->current_trace->use_max_tr) { + size = -EBUSY; + goto out_unlock; + } +#endif + if (!info->spare) - info->spare = ring_buffer_alloc_read_page(info->tr->buffer, info->cpu); + info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer, + iter->cpu_file); + size = -ENOMEM; if (!info->spare) - return -ENOMEM; + goto out_unlock; /* Do we have previous read data to read? */ if (info->read < PAGE_SIZE) goto read; - trace_access_lock(info->cpu); - ret = ring_buffer_read_page(info->tr->buffer, + again: + trace_access_lock(iter->cpu_file); + ret = ring_buffer_read_page(iter->trace_buffer->buffer, &info->spare, count, - info->cpu, 0); - trace_access_unlock(info->cpu); - if (ret < 0) - return 0; + iter->cpu_file, 0); + trace_access_unlock(iter->cpu_file); - info->read = 0; + if (ret < 0) { + if (trace_empty(iter)) { + if ((filp->f_flags & O_NONBLOCK)) { + size = -EAGAIN; + goto out_unlock; + } + mutex_unlock(&trace_types_lock); + iter->trace->wait_pipe(iter); + mutex_lock(&trace_types_lock); + if (signal_pending(current)) { + size = -EINTR; + goto out_unlock; + } + goto again; + } + size = 0; + goto out_unlock; + } -read: + info->read = 0; + read: size = PAGE_SIZE - info->read; if (size > count) size = count; ret = copy_to_user(ubuf, info->spare + info->read, size); - if (ret == size) - return -EFAULT; + if (ret == size) { + size = -EFAULT; + goto out_unlock; + } size -= ret; *ppos += size; info->read += size; + out_unlock: + mutex_unlock(&trace_types_lock); + return size; } static int tracing_buffers_release(struct inode *inode, struct file *file) { struct ftrace_buffer_info *info = file->private_data; + struct trace_iterator *iter = &info->iter; + + mutex_lock(&trace_types_lock); + + WARN_ON(!iter->tr->ref); + iter->tr->ref--; if (info->spare) - ring_buffer_free_read_page(info->tr->buffer, info->spare); + ring_buffer_free_read_page(iter->trace_buffer->buffer, info->spare); kfree(info); + mutex_unlock(&trace_types_lock); + return 0; } @@ -4259,6 +4930,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, unsigned int flags) { struct ftrace_buffer_info *info = file->private_data; + struct trace_iterator *iter = &info->iter; struct partial_page partial_def[PIPE_DEF_BUFFERS]; struct page *pages_def[PIPE_DEF_BUFFERS]; struct splice_pipe_desc spd = { @@ -4271,10 +4943,21 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, }; struct buffer_ref *ref; int entries, size, i; - size_t ret; + ssize_t ret; - if (splice_grow_spd(pipe, &spd)) - return -ENOMEM; + mutex_lock(&trace_types_lock); + +#ifdef CONFIG_TRACER_MAX_TRACE + if (iter->snapshot && iter->tr->current_trace->use_max_tr) { + ret = -EBUSY; + goto out; + } +#endif + + if (splice_grow_spd(pipe, &spd)) { + ret = -ENOMEM; + goto out; + } if (*ppos & (PAGE_SIZE - 1)) { ret = -EINVAL; @@ -4289,8 +4972,9 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, len &= PAGE_MASK; } - trace_access_lock(info->cpu); - entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); + again: + trace_access_lock(iter->cpu_file); + entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) { struct page *page; @@ -4301,15 +4985,15 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, break; ref->ref = 1; - ref->buffer = info->tr->buffer; - ref->page = ring_buffer_alloc_read_page(ref->buffer, info->cpu); + ref->buffer = iter->trace_buffer->buffer; + ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file); if (!ref->page) { kfree(ref); break; } r = ring_buffer_read_page(ref->buffer, &ref->page, - len, info->cpu, 1); + len, iter->cpu_file, 1); if (r < 0) { ring_buffer_free_read_page(ref->buffer, ref->page); kfree(ref); @@ -4333,31 +5017,40 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, spd.nr_pages++; *ppos += PAGE_SIZE; - entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); + entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); } - trace_access_unlock(info->cpu); + trace_access_unlock(iter->cpu_file); spd.nr_pages = i; /* did we read anything? */ if (!spd.nr_pages) { - if (flags & SPLICE_F_NONBLOCK) + if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) { ret = -EAGAIN; - else - ret = 0; - /* TODO: block */ - goto out; + goto out; + } + mutex_unlock(&trace_types_lock); + iter->trace->wait_pipe(iter); + mutex_lock(&trace_types_lock); + if (signal_pending(current)) { + ret = -EINTR; + goto out; + } + goto again; } ret = splice_to_pipe(pipe, &spd); splice_shrink_spd(&spd); out: + mutex_unlock(&trace_types_lock); + return ret; } static const struct file_operations tracing_buffers_fops = { .open = tracing_buffers_open, .read = tracing_buffers_read, + .poll = tracing_buffers_poll, .release = tracing_buffers_release, .splice_read = tracing_buffers_splice_read, .llseek = no_llseek, @@ -4367,12 +5060,14 @@ static ssize_t tracing_stats_read(struct file *filp, char __user *ubuf, size_t count, loff_t *ppos) { - unsigned long cpu = (unsigned long)filp->private_data; - struct trace_array *tr = &global_trace; + struct trace_cpu *tc = filp->private_data; + struct trace_array *tr = tc->tr; + struct trace_buffer *trace_buf = &tr->trace_buffer; struct trace_seq *s; unsigned long cnt; unsigned long long t; unsigned long usec_rem; + int cpu = tc->cpu; s = kmalloc(sizeof(*s), GFP_KERNEL); if (!s) @@ -4380,40 +5075,43 @@ tracing_stats_read(struct file *filp, char __user *ubuf, trace_seq_init(s); - cnt = ring_buffer_entries_cpu(tr->buffer, cpu); + cnt = ring_buffer_entries_cpu(trace_buf->buffer, cpu); trace_seq_printf(s, "entries: %ld\n", cnt); - cnt = ring_buffer_overrun_cpu(tr->buffer, cpu); + cnt = ring_buffer_overrun_cpu(trace_buf->buffer, cpu); trace_seq_printf(s, "overrun: %ld\n", cnt); - cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu); + cnt = ring_buffer_commit_overrun_cpu(trace_buf->buffer, cpu); trace_seq_printf(s, "commit overrun: %ld\n", cnt); - cnt = ring_buffer_bytes_cpu(tr->buffer, cpu); + cnt = ring_buffer_bytes_cpu(trace_buf->buffer, cpu); trace_seq_printf(s, "bytes: %ld\n", cnt); if (trace_clocks[trace_clock_id].in_ns) { /* local or global for trace_clock */ - t = ns2usecs(ring_buffer_oldest_event_ts(tr->buffer, cpu)); + t = ns2usecs(ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); usec_rem = do_div(t, USEC_PER_SEC); trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n", t, usec_rem); - t = ns2usecs(ring_buffer_time_stamp(tr->buffer, cpu)); + t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer, cpu)); usec_rem = do_div(t, USEC_PER_SEC); trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem); } else { /* counter or tsc mode for trace_clock */ trace_seq_printf(s, "oldest event ts: %llu\n", - ring_buffer_oldest_event_ts(tr->buffer, cpu)); + ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); trace_seq_printf(s, "now ts: %llu\n", - ring_buffer_time_stamp(tr->buffer, cpu)); + ring_buffer_time_stamp(trace_buf->buffer, cpu)); } - cnt = ring_buffer_dropped_events_cpu(tr->buffer, cpu); + cnt = ring_buffer_dropped_events_cpu(trace_buf->buffer, cpu); trace_seq_printf(s, "dropped events: %ld\n", cnt); + cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu); + trace_seq_printf(s, "read events: %ld\n", cnt); + count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); kfree(s); @@ -4463,60 +5161,161 @@ static const struct file_operations tracing_dyn_info_fops = { .read = tracing_read_dyn_info, .llseek = generic_file_llseek, }; -#endif +#endif /* CONFIG_DYNAMIC_FTRACE */ -static struct dentry *d_tracer; +#if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) +static void +ftrace_snapshot(unsigned long ip, unsigned long parent_ip, void **data) +{ + tracing_snapshot(); +} -struct dentry *tracing_init_dentry(void) +static void +ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip, void **data) { - static int once; + unsigned long *count = (long *)data; - if (d_tracer) - return d_tracer; + if (!*count) + return; + + if (*count != -1) + (*count)--; + + tracing_snapshot(); +} + +static int +ftrace_snapshot_print(struct seq_file *m, unsigned long ip, + struct ftrace_probe_ops *ops, void *data) +{ + long count = (long)data; + + seq_printf(m, "%ps:", (void *)ip); + + seq_printf(m, "snapshot"); + + if (count == -1) + seq_printf(m, ":unlimited\n"); + else + seq_printf(m, ":count=%ld\n", count); + + return 0; +} + +static struct ftrace_probe_ops snapshot_probe_ops = { + .func = ftrace_snapshot, + .print = ftrace_snapshot_print, +}; + +static struct ftrace_probe_ops snapshot_count_probe_ops = { + .func = ftrace_count_snapshot, + .print = ftrace_snapshot_print, +}; + +static int +ftrace_trace_snapshot_callback(struct ftrace_hash *hash, + char *glob, char *cmd, char *param, int enable) +{ + struct ftrace_probe_ops *ops; + void *count = (void *)-1; + char *number; + int ret; + + /* hash funcs only work with set_ftrace_filter */ + if (!enable) + return -EINVAL; + + ops = param ? &snapshot_count_probe_ops : &snapshot_probe_ops; + + if (glob[0] == '!') { + unregister_ftrace_function_probe_func(glob+1, ops); + return 0; + } + + if (!param) + goto out_reg; + + number = strsep(¶m, ":"); + + if (!strlen(number)) + goto out_reg; + + /* + * We use the callback data field (which is a pointer) + * as our counter. + */ + ret = kstrtoul(number, 0, (unsigned long *)&count); + if (ret) + return ret; + + out_reg: + ret = register_ftrace_function_probe(glob, ops, count); + + if (ret >= 0) + alloc_snapshot(&global_trace); + + return ret < 0 ? ret : 0; +} + +static struct ftrace_func_command ftrace_snapshot_cmd = { + .name = "snapshot", + .func = ftrace_trace_snapshot_callback, +}; + +static int register_snapshot_cmd(void) +{ + return register_ftrace_command(&ftrace_snapshot_cmd); +} +#else +static inline int register_snapshot_cmd(void) { return 0; } +#endif /* defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) */ + +struct dentry *tracing_init_dentry_tr(struct trace_array *tr) +{ + if (tr->dir) + return tr->dir; if (!debugfs_initialized()) return NULL; - d_tracer = debugfs_create_dir("tracing", NULL); + if (tr->flags & TRACE_ARRAY_FL_GLOBAL) + tr->dir = debugfs_create_dir("tracing", NULL); - if (!d_tracer && !once) { - once = 1; - pr_warning("Could not create debugfs directory 'tracing'\n"); - return NULL; - } + if (!tr->dir) + pr_warn_once("Could not create debugfs directory 'tracing'\n"); - return d_tracer; + return tr->dir; } -static struct dentry *d_percpu; +struct dentry *tracing_init_dentry(void) +{ + return tracing_init_dentry_tr(&global_trace); +} -struct dentry *tracing_dentry_percpu(void) +static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu) { - static int once; struct dentry *d_tracer; - if (d_percpu) - return d_percpu; - - d_tracer = tracing_init_dentry(); + if (tr->percpu_dir) + return tr->percpu_dir; + d_tracer = tracing_init_dentry_tr(tr); if (!d_tracer) return NULL; - d_percpu = debugfs_create_dir("per_cpu", d_tracer); + tr->percpu_dir = debugfs_create_dir("per_cpu", d_tracer); - if (!d_percpu && !once) { - once = 1; - pr_warning("Could not create debugfs directory 'per_cpu'\n"); - return NULL; - } + WARN_ONCE(!tr->percpu_dir, + "Could not create debugfs directory 'per_cpu/%d'\n", cpu); - return d_percpu; + return tr->percpu_dir; } -static void tracing_init_debugfs_percpu(long cpu) +static void +tracing_init_debugfs_percpu(struct trace_array *tr, long cpu) { - struct dentry *d_percpu = tracing_dentry_percpu(); + struct trace_array_cpu *data = per_cpu_ptr(tr->trace_buffer.data, cpu); + struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu); struct dentry *d_cpu; char cpu_dir[30]; /* 30 characters should be more than enough */ @@ -4532,20 +5331,28 @@ static void tracing_init_debugfs_percpu(long cpu) /* per cpu trace_pipe */ trace_create_file("trace_pipe", 0444, d_cpu, - (void *) cpu, &tracing_pipe_fops); + (void *)&data->trace_cpu, &tracing_pipe_fops); /* per cpu trace */ trace_create_file("trace", 0644, d_cpu, - (void *) cpu, &tracing_fops); + (void *)&data->trace_cpu, &tracing_fops); trace_create_file("trace_pipe_raw", 0444, d_cpu, - (void *) cpu, &tracing_buffers_fops); + (void *)&data->trace_cpu, &tracing_buffers_fops); trace_create_file("stats", 0444, d_cpu, - (void *) cpu, &tracing_stats_fops); + (void *)&data->trace_cpu, &tracing_stats_fops); trace_create_file("buffer_size_kb", 0444, d_cpu, - (void *) cpu, &tracing_entries_fops); + (void *)&data->trace_cpu, &tracing_entries_fops); + +#ifdef CONFIG_TRACER_SNAPSHOT + trace_create_file("snapshot", 0644, d_cpu, + (void *)&data->trace_cpu, &snapshot_fops); + + trace_create_file("snapshot_raw", 0444, d_cpu, + (void *)&data->trace_cpu, &snapshot_raw_fops); +#endif } #ifdef CONFIG_FTRACE_SELFTEST @@ -4556,6 +5363,7 @@ static void tracing_init_debugfs_percpu(long cpu) struct trace_option_dentry { struct tracer_opt *opt; struct tracer_flags *flags; + struct trace_array *tr; struct dentry *entry; }; @@ -4591,7 +5399,7 @@ trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, if (!!(topt->flags->val & topt->opt->bit) != val) { mutex_lock(&trace_types_lock); - ret = __set_tracer_option(current_trace, topt->flags, + ret = __set_tracer_option(topt->tr->current_trace, topt->flags, topt->opt, !val); mutex_unlock(&trace_types_lock); if (ret) @@ -4630,6 +5438,7 @@ static ssize_t trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { + struct trace_array *tr = &global_trace; long index = (long)filp->private_data; unsigned long val; int ret; @@ -4640,7 +5449,13 @@ trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, if (val != 0 && val != 1) return -EINVAL; - set_tracer_flags(1 << index, val); + + mutex_lock(&trace_types_lock); + ret = set_tracer_flag(tr, 1 << index, val); + mutex_unlock(&trace_types_lock); + + if (ret < 0) + return ret; *ppos += cnt; @@ -4670,40 +5485,41 @@ struct dentry *trace_create_file(const char *name, } -static struct dentry *trace_options_init_dentry(void) +static struct dentry *trace_options_init_dentry(struct trace_array *tr) { struct dentry *d_tracer; - static struct dentry *t_options; - if (t_options) - return t_options; + if (tr->options) + return tr->options; - d_tracer = tracing_init_dentry(); + d_tracer = tracing_init_dentry_tr(tr); if (!d_tracer) return NULL; - t_options = debugfs_create_dir("options", d_tracer); - if (!t_options) { + tr->options = debugfs_create_dir("options", d_tracer); + if (!tr->options) { pr_warning("Could not create debugfs directory 'options'\n"); return NULL; } - return t_options; + return tr->options; } static void -create_trace_option_file(struct trace_option_dentry *topt, +create_trace_option_file(struct trace_array *tr, + struct trace_option_dentry *topt, struct tracer_flags *flags, struct tracer_opt *opt) { struct dentry *t_options; - t_options = trace_options_init_dentry(); + t_options = trace_options_init_dentry(tr); if (!t_options) return; topt->flags = flags; topt->opt = opt; + topt->tr = tr; topt->entry = trace_create_file(opt->name, 0644, t_options, topt, &trace_options_fops); @@ -4711,7 +5527,7 @@ create_trace_option_file(struct trace_option_dentry *topt, } static struct trace_option_dentry * -create_trace_option_files(struct tracer *tracer) +create_trace_option_files(struct trace_array *tr, struct tracer *tracer) { struct trace_option_dentry *topts; struct tracer_flags *flags; @@ -4736,7 +5552,7 @@ create_trace_option_files(struct tracer *tracer) return NULL; for (cnt = 0; opts[cnt].name; cnt++) - create_trace_option_file(&topts[cnt], flags, + create_trace_option_file(tr, &topts[cnt], flags, &opts[cnt]); return topts; @@ -4759,11 +5575,12 @@ destroy_trace_option_files(struct trace_option_dentry *topts) } static struct dentry * -create_trace_option_core_file(const char *option, long index) +create_trace_option_core_file(struct trace_array *tr, + const char *option, long index) { struct dentry *t_options; - t_options = trace_options_init_dentry(); + t_options = trace_options_init_dentry(tr); if (!t_options) return NULL; @@ -4771,17 +5588,17 @@ create_trace_option_core_file(const char *option, long index) &trace_options_core_fops); } -static __init void create_trace_options_dir(void) +static __init void create_trace_options_dir(struct trace_array *tr) { struct dentry *t_options; int i; - t_options = trace_options_init_dentry(); + t_options = trace_options_init_dentry(tr); if (!t_options) return; for (i = 0; trace_options[i]; i++) - create_trace_option_core_file(trace_options[i], i); + create_trace_option_core_file(tr, trace_options[i], i); } static ssize_t @@ -4789,7 +5606,7 @@ rb_simple_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_array *tr = filp->private_data; - struct ring_buffer *buffer = tr->buffer; + struct ring_buffer *buffer = tr->trace_buffer.buffer; char buf[64]; int r; @@ -4808,7 +5625,7 @@ rb_simple_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_array *tr = filp->private_data; - struct ring_buffer *buffer = tr->buffer; + struct ring_buffer *buffer = tr->trace_buffer.buffer; unsigned long val; int ret; @@ -4820,12 +5637,12 @@ rb_simple_write(struct file *filp, const char __user *ubuf, mutex_lock(&trace_types_lock); if (val) { ring_buffer_record_on(buffer); - if (current_trace->start) - current_trace->start(tr); + if (tr->current_trace->start) + tr->current_trace->start(tr); } else { ring_buffer_record_off(buffer); - if (current_trace->stop) - current_trace->stop(tr); + if (tr->current_trace->stop) + tr->current_trace->stop(tr); } mutex_unlock(&trace_types_lock); } @@ -4842,23 +5659,310 @@ static const struct file_operations rb_simple_fops = { .llseek = default_llseek, }; +struct dentry *trace_instance_dir; + +static void +init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer); + +static void init_trace_buffers(struct trace_array *tr, struct trace_buffer *buf) +{ + int cpu; + + for_each_tracing_cpu(cpu) { + memset(per_cpu_ptr(buf->data, cpu), 0, sizeof(struct trace_array_cpu)); + per_cpu_ptr(buf->data, cpu)->trace_cpu.cpu = cpu; + per_cpu_ptr(buf->data, cpu)->trace_cpu.tr = tr; + } +} + +static int +allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size) +{ + enum ring_buffer_flags rb_flags; + + rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; + + buf->buffer = ring_buffer_alloc(size, rb_flags); + if (!buf->buffer) + return -ENOMEM; + + buf->data = alloc_percpu(struct trace_array_cpu); + if (!buf->data) { + ring_buffer_free(buf->buffer); + return -ENOMEM; + } + + init_trace_buffers(tr, buf); + + /* Allocate the first page for all buffers */ + set_buffer_entries(&tr->trace_buffer, + ring_buffer_size(tr->trace_buffer.buffer, 0)); + + return 0; +} + +static int allocate_trace_buffers(struct trace_array *tr, int size) +{ + int ret; + + ret = allocate_trace_buffer(tr, &tr->trace_buffer, size); + if (ret) + return ret; + +#ifdef CONFIG_TRACER_MAX_TRACE + ret = allocate_trace_buffer(tr, &tr->max_buffer, + allocate_snapshot ? size : 1); + if (WARN_ON(ret)) { + ring_buffer_free(tr->trace_buffer.buffer); + free_percpu(tr->trace_buffer.data); + return -ENOMEM; + } + tr->allocated_snapshot = allocate_snapshot; + + /* + * Only the top level trace array gets its snapshot allocated + * from the kernel command line. + */ + allocate_snapshot = false; +#endif + return 0; +} + +static int new_instance_create(const char *name) +{ + struct trace_array *tr; + int ret; + + mutex_lock(&trace_types_lock); + + ret = -EEXIST; + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (tr->name && strcmp(tr->name, name) == 0) + goto out_unlock; + } + + ret = -ENOMEM; + tr = kzalloc(sizeof(*tr), GFP_KERNEL); + if (!tr) + goto out_unlock; + + tr->name = kstrdup(name, GFP_KERNEL); + if (!tr->name) + goto out_free_tr; + + raw_spin_lock_init(&tr->start_lock); + + tr->current_trace = &nop_trace; + + INIT_LIST_HEAD(&tr->systems); + INIT_LIST_HEAD(&tr->events); + + if (allocate_trace_buffers(tr, trace_buf_size) < 0) + goto out_free_tr; + + /* Holder for file callbacks */ + tr->trace_cpu.cpu = RING_BUFFER_ALL_CPUS; + tr->trace_cpu.tr = tr; + + tr->dir = debugfs_create_dir(name, trace_instance_dir); + if (!tr->dir) + goto out_free_tr; + + ret = event_trace_add_tracer(tr->dir, tr); + if (ret) + goto out_free_tr; + + init_tracer_debugfs(tr, tr->dir); + + list_add(&tr->list, &ftrace_trace_arrays); + + mutex_unlock(&trace_types_lock); + + return 0; + + out_free_tr: + if (tr->trace_buffer.buffer) + ring_buffer_free(tr->trace_buffer.buffer); + kfree(tr->name); + kfree(tr); + + out_unlock: + mutex_unlock(&trace_types_lock); + + return ret; + +} + +static int instance_delete(const char *name) +{ + struct trace_array *tr; + int found = 0; + int ret; + + mutex_lock(&trace_types_lock); + + ret = -ENODEV; + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (tr->name && strcmp(tr->name, name) == 0) { + found = 1; + break; + } + } + if (!found) + goto out_unlock; + + ret = -EBUSY; + if (tr->ref) + goto out_unlock; + + list_del(&tr->list); + + event_trace_del_tracer(tr); + debugfs_remove_recursive(tr->dir); + free_percpu(tr->trace_buffer.data); + ring_buffer_free(tr->trace_buffer.buffer); + + kfree(tr->name); + kfree(tr); + + ret = 0; + + out_unlock: + mutex_unlock(&trace_types_lock); + + return ret; +} + +static int instance_mkdir (struct inode *inode, struct dentry *dentry, umode_t mode) +{ + struct dentry *parent; + int ret; + + /* Paranoid: Make sure the parent is the "instances" directory */ + parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias); + if (WARN_ON_ONCE(parent != trace_instance_dir)) + return -ENOENT; + + /* + * The inode mutex is locked, but debugfs_create_dir() will also + * take the mutex. As the instances directory can not be destroyed + * or changed in any other way, it is safe to unlock it, and + * let the dentry try. If two users try to make the same dir at + * the same time, then the new_instance_create() will determine the + * winner. + */ + mutex_unlock(&inode->i_mutex); + + ret = new_instance_create(dentry->d_iname); + + mutex_lock(&inode->i_mutex); + + return ret; +} + +static int instance_rmdir(struct inode *inode, struct dentry *dentry) +{ + struct dentry *parent; + int ret; + + /* Paranoid: Make sure the parent is the "instances" directory */ + parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias); + if (WARN_ON_ONCE(parent != trace_instance_dir)) + return -ENOENT; + + /* The caller did a dget() on dentry */ + mutex_unlock(&dentry->d_inode->i_mutex); + + /* + * The inode mutex is locked, but debugfs_create_dir() will also + * take the mutex. As the instances directory can not be destroyed + * or changed in any other way, it is safe to unlock it, and + * let the dentry try. If two users try to make the same dir at + * the same time, then the instance_delete() will determine the + * winner. + */ + mutex_unlock(&inode->i_mutex); + + ret = instance_delete(dentry->d_iname); + + mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT); + mutex_lock(&dentry->d_inode->i_mutex); + + return ret; +} + +static const struct inode_operations instance_dir_inode_operations = { + .lookup = simple_lookup, + .mkdir = instance_mkdir, + .rmdir = instance_rmdir, +}; + +static __init void create_trace_instances(struct dentry *d_tracer) +{ + trace_instance_dir = debugfs_create_dir("instances", d_tracer); + if (WARN_ON(!trace_instance_dir)) + return; + + /* Hijack the dir inode operations, to allow mkdir */ + trace_instance_dir->d_inode->i_op = &instance_dir_inode_operations; +} + +static void +init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer) +{ + int cpu; + + trace_create_file("trace_options", 0644, d_tracer, + tr, &tracing_iter_fops); + + trace_create_file("trace", 0644, d_tracer, + (void *)&tr->trace_cpu, &tracing_fops); + + trace_create_file("trace_pipe", 0444, d_tracer, + (void *)&tr->trace_cpu, &tracing_pipe_fops); + + trace_create_file("buffer_size_kb", 0644, d_tracer, + (void *)&tr->trace_cpu, &tracing_entries_fops); + + trace_create_file("buffer_total_size_kb", 0444, d_tracer, + tr, &tracing_total_entries_fops); + + trace_create_file("free_buffer", 0644, d_tracer, + tr, &tracing_free_buffer_fops); + + trace_create_file("trace_marker", 0220, d_tracer, + tr, &tracing_mark_fops); + + trace_create_file("trace_clock", 0644, d_tracer, tr, + &trace_clock_fops); + + trace_create_file("tracing_on", 0644, d_tracer, + tr, &rb_simple_fops); + +#ifdef CONFIG_TRACER_SNAPSHOT + trace_create_file("snapshot", 0644, d_tracer, + (void *)&tr->trace_cpu, &snapshot_fops); +#endif + + for_each_tracing_cpu(cpu) + tracing_init_debugfs_percpu(tr, cpu); + +} + static __init int tracer_init_debugfs(void) { struct dentry *d_tracer; - int cpu; trace_access_lock_init(); d_tracer = tracing_init_dentry(); + if (!d_tracer) + return 0; - trace_create_file("trace_options", 0644, d_tracer, - NULL, &tracing_iter_fops); + init_tracer_debugfs(&global_trace, d_tracer); trace_create_file("tracing_cpumask", 0644, d_tracer, - NULL, &tracing_cpumask_fops); - - trace_create_file("trace", 0644, d_tracer, - (void *) TRACE_PIPE_ALL_CPU, &tracing_fops); + &global_trace, &tracing_cpumask_fops); trace_create_file("available_tracers", 0444, d_tracer, &global_trace, &show_traces_fops); @@ -4877,39 +5981,17 @@ static __init int tracer_init_debugfs(void) trace_create_file("README", 0444, d_tracer, NULL, &tracing_readme_fops); - trace_create_file("trace_pipe", 0444, d_tracer, - (void *) TRACE_PIPE_ALL_CPU, &tracing_pipe_fops); - - trace_create_file("buffer_size_kb", 0644, d_tracer, - (void *) RING_BUFFER_ALL_CPUS, &tracing_entries_fops); - - trace_create_file("buffer_total_size_kb", 0444, d_tracer, - &global_trace, &tracing_total_entries_fops); - - trace_create_file("free_buffer", 0644, d_tracer, - &global_trace, &tracing_free_buffer_fops); - - trace_create_file("trace_marker", 0220, d_tracer, - NULL, &tracing_mark_fops); - trace_create_file("saved_cmdlines", 0444, d_tracer, NULL, &tracing_saved_cmdlines_fops); - trace_create_file("trace_clock", 0644, d_tracer, NULL, - &trace_clock_fops); - - trace_create_file("tracing_on", 0644, d_tracer, - &global_trace, &rb_simple_fops); - #ifdef CONFIG_DYNAMIC_FTRACE trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, &ftrace_update_tot_cnt, &tracing_dyn_info_fops); #endif - create_trace_options_dir(); + create_trace_instances(d_tracer); - for_each_tracing_cpu(cpu) - tracing_init_debugfs_percpu(cpu); + create_trace_options_dir(&global_trace); return 0; } @@ -4965,8 +6047,8 @@ void trace_printk_seq(struct trace_seq *s) { /* Probably should print a warning here. */ - if (s->len >= 1000) - s->len = 1000; + if (s->len >= TRACE_MAX_PRINT) + s->len = TRACE_MAX_PRINT; /* should be zero ended, but we are paranoid. */ s->buffer[s->len] = 0; @@ -4979,45 +6061,43 @@ trace_printk_seq(struct trace_seq *s) void trace_init_global_iter(struct trace_iterator *iter) { iter->tr = &global_trace; - iter->trace = current_trace; - iter->cpu_file = TRACE_PIPE_ALL_CPU; + iter->trace = iter->tr->current_trace; + iter->cpu_file = RING_BUFFER_ALL_CPUS; + iter->trace_buffer = &global_trace.trace_buffer; } -static void -__ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) +void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { - static arch_spinlock_t ftrace_dump_lock = - (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; /* use static because iter can be a bit big for the stack */ static struct trace_iterator iter; + static atomic_t dump_running; unsigned int old_userobj; - static int dump_ran; unsigned long flags; int cnt = 0, cpu; - /* only one dump */ - local_irq_save(flags); - arch_spin_lock(&ftrace_dump_lock); - if (dump_ran) - goto out; - - dump_ran = 1; + /* Only allow one dump user at a time. */ + if (atomic_inc_return(&dump_running) != 1) { + atomic_dec(&dump_running); + return; + } + /* + * Always turn off tracing when we dump. + * We don't need to show trace output of what happens + * between multiple crashes. + * + * If the user does a sysrq-z, then they can re-enable + * tracing with echo 1 > tracing_on. + */ tracing_off(); - /* Did function tracer already get disabled? */ - if (ftrace_is_dead()) { - printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n"); - printk("# MAY BE MISSING FUNCTION EVENTS\n"); - } - - if (disable_tracing) - ftrace_kill(); + local_irq_save(flags); + /* Simulate the iterator */ trace_init_global_iter(&iter); for_each_tracing_cpu(cpu) { - atomic_inc(&iter.tr->data[cpu]->disabled); + atomic_inc(&per_cpu_ptr(iter.tr->trace_buffer.data, cpu)->disabled); } old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ; @@ -5025,13 +6105,9 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) /* don't look at user memory in panic mode */ trace_flags &= ~TRACE_ITER_SYM_USEROBJ; - /* Simulate the iterator */ - iter.tr = &global_trace; - iter.trace = current_trace; - switch (oops_dump_mode) { case DUMP_ALL: - iter.cpu_file = TRACE_PIPE_ALL_CPU; + iter.cpu_file = RING_BUFFER_ALL_CPUS; break; case DUMP_ORIG: iter.cpu_file = raw_smp_processor_id(); @@ -5040,11 +6116,17 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) goto out_enable; default: printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n"); - iter.cpu_file = TRACE_PIPE_ALL_CPU; + iter.cpu_file = RING_BUFFER_ALL_CPUS; } printk(KERN_TRACE "Dumping ftrace buffer:\n"); + /* Did function tracer already get disabled? */ + if (ftrace_is_dead()) { + printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n"); + printk("# MAY BE MISSING FUNCTION EVENTS\n"); + } + /* * We need to stop all tracing on all CPUS to read the * the next buffer. This is a bit expensive, but is @@ -5084,33 +6166,19 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) printk(KERN_TRACE "---------------------------------\n"); out_enable: - /* Re-enable tracing if requested */ - if (!disable_tracing) { - trace_flags |= old_userobj; + trace_flags |= old_userobj; - for_each_tracing_cpu(cpu) { - atomic_dec(&iter.tr->data[cpu]->disabled); - } - tracing_on(); + for_each_tracing_cpu(cpu) { + atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); } - - out: - arch_spin_unlock(&ftrace_dump_lock); + atomic_dec(&dump_running); local_irq_restore(flags); } - -/* By default: disable tracing after the dump */ -void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) -{ - __ftrace_dump(true, oops_dump_mode); -} EXPORT_SYMBOL_GPL(ftrace_dump); __init static int tracer_alloc_buffers(void) { int ring_buf_size; - enum ring_buffer_flags rb_flags; - int i; int ret = -ENOMEM; @@ -5131,49 +6199,27 @@ __init static int tracer_alloc_buffers(void) else ring_buf_size = 1; - rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; - cpumask_copy(tracing_buffer_mask, cpu_possible_mask); cpumask_copy(tracing_cpumask, cpu_all_mask); + raw_spin_lock_init(&global_trace.start_lock); + /* TODO: make the number of buffers hot pluggable with CPUS */ - global_trace.buffer = ring_buffer_alloc(ring_buf_size, rb_flags); - if (!global_trace.buffer) { + if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) { printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); WARN_ON(1); goto out_free_cpumask; } + if (global_trace.buffer_disabled) tracing_off(); - -#ifdef CONFIG_TRACER_MAX_TRACE - max_tr.buffer = ring_buffer_alloc(1, rb_flags); - if (!max_tr.buffer) { - printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n"); - WARN_ON(1); - ring_buffer_free(global_trace.buffer); - goto out_free_cpumask; - } -#endif - - /* Allocate the first page for all buffers */ - for_each_tracing_cpu(i) { - global_trace.data[i] = &per_cpu(global_trace_cpu, i); - max_tr.data[i] = &per_cpu(max_tr_data, i); - } - - set_buffer_entries(&global_trace, - ring_buffer_size(global_trace.buffer, 0)); -#ifdef CONFIG_TRACER_MAX_TRACE - set_buffer_entries(&max_tr, 1); -#endif - trace_init_cmdlines(); - init_irq_work(&trace_work_wakeup, trace_wake_up); register_tracer(&nop_trace); - current_trace = &nop_trace; + + global_trace.current_trace = &nop_trace; + /* All seems OK, enable tracing */ tracing_disabled = 0; @@ -5182,16 +6228,32 @@ __init static int tracer_alloc_buffers(void) register_die_notifier(&trace_die_notifier); + global_trace.flags = TRACE_ARRAY_FL_GLOBAL; + + /* Holder for file callbacks */ + global_trace.trace_cpu.cpu = RING_BUFFER_ALL_CPUS; + global_trace.trace_cpu.tr = &global_trace; + + INIT_LIST_HEAD(&global_trace.systems); + INIT_LIST_HEAD(&global_trace.events); + list_add(&global_trace.list, &ftrace_trace_arrays); + while (trace_boot_options) { char *option; option = strsep(&trace_boot_options, ","); - trace_set_options(option); + trace_set_options(&global_trace, option); } + register_snapshot_cmd(); + return 0; out_free_cpumask: + free_percpu(global_trace.trace_buffer.data); +#ifdef CONFIG_TRACER_MAX_TRACE + free_percpu(global_trace.max_buffer.data); +#endif free_cpumask_var(tracing_cpumask); out_free_buffer_mask: free_cpumask_var(tracing_buffer_mask); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index c75d7988902c..711ca7d3e7f1 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -13,6 +13,11 @@ #include <linux/trace_seq.h> #include <linux/ftrace_event.h> +#ifdef CONFIG_FTRACE_SYSCALLS +#include <asm/unistd.h> /* For NR_SYSCALLS */ +#include <asm/syscall.h> /* some archs define it here */ +#endif + enum trace_type { __TRACE_FIRST_TYPE = 0, @@ -29,6 +34,7 @@ enum trace_type { TRACE_GRAPH_ENT, TRACE_USER_STACK, TRACE_BLK, + TRACE_BPUTS, __TRACE_LAST_TYPE, }; @@ -103,11 +109,6 @@ struct kretprobe_trace_entry_head { unsigned long ret_ip; }; -struct uprobe_trace_entry_head { - struct trace_entry ent; - unsigned long ip; -}; - /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: @@ -127,12 +128,21 @@ enum trace_flag_type { #define TRACE_BUF_SIZE 1024 +struct trace_array; + +struct trace_cpu { + struct trace_array *tr; + struct dentry *dir; + int cpu; +}; + /* * The CPU trace array - it consists of thousands of trace entries * plus some other descriptor data: (for example which task started * the trace, etc.) */ struct trace_array_cpu { + struct trace_cpu trace_cpu; atomic_t disabled; void *buffer_page; /* ring buffer spare */ @@ -151,20 +161,83 @@ struct trace_array_cpu { char comm[TASK_COMM_LEN]; }; +struct tracer; + +struct trace_buffer { + struct trace_array *tr; + struct ring_buffer *buffer; + struct trace_array_cpu __percpu *data; + cycle_t time_start; + int cpu; +}; + /* * The trace array - an array of per-CPU trace arrays. This is the * highest level data structure that individual tracers deal with. * They have on/off state as well: */ struct trace_array { - struct ring_buffer *buffer; - int cpu; + struct list_head list; + char *name; + struct trace_buffer trace_buffer; +#ifdef CONFIG_TRACER_MAX_TRACE + /* + * The max_buffer is used to snapshot the trace when a maximum + * latency is reached, or when the user initiates a snapshot. + * Some tracers will use this to store a maximum trace while + * it continues examining live traces. + * + * The buffers for the max_buffer are set up the same as the trace_buffer + * When a snapshot is taken, the buffer of the max_buffer is swapped + * with the buffer of the trace_buffer and the buffers are reset for + * the trace_buffer so the tracing can continue. + */ + struct trace_buffer max_buffer; + bool allocated_snapshot; +#endif int buffer_disabled; - cycle_t time_start; + struct trace_cpu trace_cpu; /* place holder */ +#ifdef CONFIG_FTRACE_SYSCALLS + int sys_refcount_enter; + int sys_refcount_exit; + DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls); + DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls); +#endif + int stop_count; + int clock_id; + struct tracer *current_trace; + unsigned int flags; + raw_spinlock_t start_lock; + struct dentry *dir; + struct dentry *options; + struct dentry *percpu_dir; + struct dentry *event_dir; + struct list_head systems; + struct list_head events; struct task_struct *waiter; - struct trace_array_cpu *data[NR_CPUS]; + int ref; }; +enum { + TRACE_ARRAY_FL_GLOBAL = (1 << 0) +}; + +extern struct list_head ftrace_trace_arrays; + +/* + * The global tracer (top) should be the first trace array added, + * but we check the flag anyway. + */ +static inline struct trace_array *top_trace_array(void) +{ + struct trace_array *tr; + + tr = list_entry(ftrace_trace_arrays.prev, + typeof(*tr), list); + WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); + return tr; +} + #define FTRACE_CMP_TYPE(var, type) \ __builtin_types_compatible_p(typeof(var), type *) @@ -200,6 +273,7 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\ IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \ IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \ + IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS); \ IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \ TRACE_MMIO_RW); \ IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \ @@ -283,24 +357,71 @@ struct tracer { enum print_line_t (*print_line)(struct trace_iterator *iter); /* If you handled the flag setting, return 0 */ int (*set_flag)(u32 old_flags, u32 bit, int set); + /* Return 0 if OK with change, else return non-zero */ + int (*flag_changed)(struct tracer *tracer, + u32 mask, int set); struct tracer *next; struct tracer_flags *flags; bool print_max; + bool enabled; +#ifdef CONFIG_TRACER_MAX_TRACE bool use_max_tr; +#endif }; /* Only current can touch trace_recursion */ -#define trace_recursion_inc() do { (current)->trace_recursion++; } while (0) -#define trace_recursion_dec() do { (current)->trace_recursion--; } while (0) -/* Ring buffer has the 10 LSB bits to count */ -#define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff) - -/* for function tracing recursion */ -#define TRACE_INTERNAL_BIT (1<<11) -#define TRACE_GLOBAL_BIT (1<<12) -#define TRACE_CONTROL_BIT (1<<13) +/* + * For function tracing recursion: + * The order of these bits are important. + * + * When function tracing occurs, the following steps are made: + * If arch does not support a ftrace feature: + * call internal function (uses INTERNAL bits) which calls... + * If callback is registered to the "global" list, the list + * function is called and recursion checks the GLOBAL bits. + * then this function calls... + * The function callback, which can use the FTRACE bits to + * check for recursion. + * + * Now if the arch does not suppport a feature, and it calls + * the global list function which calls the ftrace callback + * all three of these steps will do a recursion protection. + * There's no reason to do one if the previous caller already + * did. The recursion that we are protecting against will + * go through the same steps again. + * + * To prevent the multiple recursion checks, if a recursion + * bit is set that is higher than the MAX bit of the current + * check, then we know that the check was made by the previous + * caller, and we can skip the current check. + */ +enum { + TRACE_BUFFER_BIT, + TRACE_BUFFER_NMI_BIT, + TRACE_BUFFER_IRQ_BIT, + TRACE_BUFFER_SIRQ_BIT, + + /* Start of function recursion bits */ + TRACE_FTRACE_BIT, + TRACE_FTRACE_NMI_BIT, + TRACE_FTRACE_IRQ_BIT, + TRACE_FTRACE_SIRQ_BIT, + + /* GLOBAL_BITs must be greater than FTRACE_BITs */ + TRACE_GLOBAL_BIT, + TRACE_GLOBAL_NMI_BIT, + TRACE_GLOBAL_IRQ_BIT, + TRACE_GLOBAL_SIRQ_BIT, + + /* INTERNAL_BITs must be greater than GLOBAL_BITs */ + TRACE_INTERNAL_BIT, + TRACE_INTERNAL_NMI_BIT, + TRACE_INTERNAL_IRQ_BIT, + TRACE_INTERNAL_SIRQ_BIT, + + TRACE_CONTROL_BIT, /* * Abuse of the trace_recursion. @@ -309,13 +430,77 @@ struct tracer { * was called in irq context but we have irq tracing off. Since this * can only be modified by current, we can reuse trace_recursion. */ -#define TRACE_IRQ_BIT (1<<13) + TRACE_IRQ_BIT, +}; + +#define trace_recursion_set(bit) do { (current)->trace_recursion |= (1<<(bit)); } while (0) +#define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(1<<(bit)); } while (0) +#define trace_recursion_test(bit) ((current)->trace_recursion & (1<<(bit))) + +#define TRACE_CONTEXT_BITS 4 + +#define TRACE_FTRACE_START TRACE_FTRACE_BIT +#define TRACE_FTRACE_MAX ((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1) + +#define TRACE_GLOBAL_START TRACE_GLOBAL_BIT +#define TRACE_GLOBAL_MAX ((1 << (TRACE_GLOBAL_START + TRACE_CONTEXT_BITS)) - 1) + +#define TRACE_LIST_START TRACE_INTERNAL_BIT +#define TRACE_LIST_MAX ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1) + +#define TRACE_CONTEXT_MASK TRACE_LIST_MAX + +static __always_inline int trace_get_context_bit(void) +{ + int bit; + + if (in_interrupt()) { + if (in_nmi()) + bit = 0; + + else if (in_irq()) + bit = 1; + else + bit = 2; + } else + bit = 3; + + return bit; +} + +static __always_inline int trace_test_and_set_recursion(int start, int max) +{ + unsigned int val = current->trace_recursion; + int bit; -#define trace_recursion_set(bit) do { (current)->trace_recursion |= (bit); } while (0) -#define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(bit); } while (0) -#define trace_recursion_test(bit) ((current)->trace_recursion & (bit)) + /* A previous recursion check was made */ + if ((val & TRACE_CONTEXT_MASK) > max) + return 0; -#define TRACE_PIPE_ALL_CPU -1 + bit = trace_get_context_bit() + start; + if (unlikely(val & (1 << bit))) + return -1; + + val |= 1 << bit; + current->trace_recursion = val; + barrier(); + + return bit; +} + +static __always_inline void trace_clear_recursion(int bit) +{ + unsigned int val = current->trace_recursion; + + if (!bit) + return; + + bit = 1 << bit; + val &= ~bit; + + barrier(); + current->trace_recursion = val; +} static inline struct ring_buffer_iter * trace_buffer_iter(struct trace_iterator *iter, int cpu) @@ -327,10 +512,10 @@ trace_buffer_iter(struct trace_iterator *iter, int cpu) int tracer_init(struct tracer *t, struct trace_array *tr); int tracing_is_enabled(void); -void tracing_reset(struct trace_array *tr, int cpu); -void tracing_reset_online_cpus(struct trace_array *tr); +void tracing_reset(struct trace_buffer *buf, int cpu); +void tracing_reset_online_cpus(struct trace_buffer *buf); void tracing_reset_current(int cpu); -void tracing_reset_current_online_cpus(void); +void tracing_reset_all_online_cpus(void); int tracing_open_generic(struct inode *inode, struct file *filp); struct dentry *trace_create_file(const char *name, umode_t mode, @@ -338,6 +523,7 @@ struct dentry *trace_create_file(const char *name, void *data, const struct file_operations *fops); +struct dentry *tracing_init_dentry_tr(struct trace_array *tr); struct dentry *tracing_init_dentry(void); struct ring_buffer_event; @@ -471,7 +657,7 @@ extern int DYN_FTRACE_TEST_NAME(void); #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2 extern int DYN_FTRACE_TEST_NAME2(void); -extern int ring_buffer_expanded; +extern bool ring_buffer_expanded; extern bool tracing_selftest_disabled; DECLARE_PER_CPU(int, ftrace_cpu_disabled); @@ -507,6 +693,8 @@ trace_array_vprintk(struct trace_array *tr, unsigned long ip, const char *fmt, va_list args); int trace_array_printk(struct trace_array *tr, unsigned long ip, const char *fmt, ...); +int trace_array_printk_buf(struct ring_buffer *buffer, + unsigned long ip, const char *fmt, ...); void trace_printk_seq(struct trace_seq *s); enum print_line_t print_trace_line(struct trace_iterator *iter); @@ -674,6 +862,7 @@ enum trace_iterator_flags { TRACE_ITER_STOP_ON_FREE = 0x400000, TRACE_ITER_IRQ_INFO = 0x800000, TRACE_ITER_MARKERS = 0x1000000, + TRACE_ITER_FUNCTION = 0x2000000, }; /* @@ -720,8 +909,8 @@ enum { struct ftrace_event_field { struct list_head link; - char *name; - char *type; + const char *name; + const char *type; int filter_type; int offset; int size; @@ -739,12 +928,19 @@ struct event_filter { struct event_subsystem { struct list_head list; const char *name; - struct dentry *entry; struct event_filter *filter; - int nr_events; int ref_count; }; +struct ftrace_subsystem_dir { + struct list_head list; + struct event_subsystem *subsystem; + struct trace_array *tr; + struct dentry *entry; + int ref_count; + int nr_events; +}; + #define FILTER_PRED_INVALID ((unsigned short)-1) #define FILTER_PRED_IS_RIGHT (1 << 15) #define FILTER_PRED_FOLD (1 << 15) @@ -794,22 +990,20 @@ struct filter_pred { unsigned short right; }; -extern struct list_head ftrace_common_fields; - extern enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not); extern void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s); extern int apply_event_filter(struct ftrace_event_call *call, char *filter_string); -extern int apply_subsystem_event_filter(struct event_subsystem *system, +extern int apply_subsystem_event_filter(struct ftrace_subsystem_dir *dir, char *filter_string); extern void print_subsystem_event_filter(struct event_subsystem *system, struct trace_seq *s); extern int filter_assign_type(const char *type); -struct list_head * -trace_get_fields(struct ftrace_event_call *event_call); +struct ftrace_event_field * +trace_find_event_field(struct ftrace_event_call *call, char *name); static inline int filter_check_discard(struct ftrace_event_call *call, void *rec, @@ -826,6 +1020,8 @@ filter_check_discard(struct ftrace_event_call *call, void *rec, } extern void trace_event_enable_cmd_record(bool enable); +extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr); +extern int event_trace_del_tracer(struct trace_array *tr); extern struct mutex event_mutex; extern struct list_head ftrace_events; @@ -835,6 +1031,19 @@ extern const char *__stop___trace_bprintk_fmt[]; void trace_printk_init_buffers(void); void trace_printk_start_comm(void); +int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set); +int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled); + +/* + * Normal trace_printk() and friends allocates special buffers + * to do the manipulation, as well as saves the print formats + * into sections to display. But the trace infrastructure wants + * to use these without the added overhead at the price of being + * a bit slower (used mainly for warnings, where we don't care + * about performance). The internal_trace_puts() is for such + * a purpose. + */ +#define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str)) #undef FTRACE_ENTRY #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter) \ diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index 95e96842ed29..d594da0dc03c 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -32,6 +32,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) { struct ftrace_event_call *call = &event_branch; struct trace_array *tr = branch_tracer; + struct trace_array_cpu *data; struct ring_buffer_event *event; struct trace_branch *entry; struct ring_buffer *buffer; @@ -51,11 +52,12 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) local_irq_save(flags); cpu = raw_smp_processor_id(); - if (atomic_inc_return(&tr->data[cpu]->disabled) != 1) + data = per_cpu_ptr(tr->trace_buffer.data, cpu); + if (atomic_inc_return(&data->disabled) != 1) goto out; pc = preempt_count(); - buffer = tr->buffer; + buffer = tr->trace_buffer.buffer; event = trace_buffer_lock_reserve(buffer, TRACE_BRANCH, sizeof(*entry), flags, pc); if (!event) @@ -80,7 +82,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) __buffer_unlock_commit(buffer, event); out: - atomic_dec(&tr->data[cpu]->disabled); + atomic_dec(&data->disabled); local_irq_restore(flags); } diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c index 394783531cbb..26dc348332b7 100644 --- a/kernel/trace/trace_clock.c +++ b/kernel/trace/trace_clock.c @@ -21,8 +21,6 @@ #include <linux/ktime.h> #include <linux/trace_clock.h> -#include "trace.h" - /* * trace_clock_local(): the simplest and least coherent tracing clock. * @@ -44,6 +42,7 @@ u64 notrace trace_clock_local(void) return clock; } +EXPORT_SYMBOL_GPL(trace_clock_local); /* * trace_clock(): 'between' trace clock. Not completely serialized, @@ -58,6 +57,16 @@ u64 notrace trace_clock(void) return local_clock(); } +/* + * trace_jiffy_clock(): Simply use jiffies as a clock counter. + */ +u64 notrace trace_clock_jiffies(void) +{ + u64 jiffy = jiffies - INITIAL_JIFFIES; + + /* Return nsecs */ + return (u64)jiffies_to_usecs(jiffy) * 1000ULL; +} /* * trace_clock_global(): special globally coherent trace clock @@ -86,7 +95,7 @@ u64 notrace trace_clock_global(void) local_irq_save(flags); this_cpu = raw_smp_processor_id(); - now = cpu_clock(this_cpu); + now = sched_clock_cpu(this_cpu); /* * If in an NMI context then dont risk lockups and return the * cpu_clock() time: diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index 4108e1250ca2..e2d027ac66a2 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -223,8 +223,8 @@ FTRACE_ENTRY(bprint, bprint_entry, __dynamic_array( u32, buf ) ), - F_printk("%08lx fmt:%p", - __entry->ip, __entry->fmt), + F_printk("%pf: %s", + (void *)__entry->ip, __entry->fmt), FILTER_OTHER ); @@ -238,8 +238,23 @@ FTRACE_ENTRY(print, print_entry, __dynamic_array( char, buf ) ), - F_printk("%08lx %s", - __entry->ip, __entry->buf), + F_printk("%pf: %s", + (void *)__entry->ip, __entry->buf), + + FILTER_OTHER +); + +FTRACE_ENTRY(bputs, bputs_entry, + + TRACE_BPUTS, + + F_STRUCT( + __field( unsigned long, ip ) + __field( const char *, str ) + ), + + F_printk("%pf: %s", + (void *)__entry->ip, __entry->str), FILTER_OTHER ); diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 880073d0b946..53582e982e51 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -34,9 +34,27 @@ char event_storage[EVENT_STORAGE_SIZE]; EXPORT_SYMBOL_GPL(event_storage); LIST_HEAD(ftrace_events); -LIST_HEAD(ftrace_common_fields); +static LIST_HEAD(ftrace_common_fields); -struct list_head * +#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO) + +static struct kmem_cache *field_cachep; +static struct kmem_cache *file_cachep; + +/* Double loops, do not use break, only goto's work */ +#define do_for_each_event_file(tr, file) \ + list_for_each_entry(tr, &ftrace_trace_arrays, list) { \ + list_for_each_entry(file, &tr->events, list) + +#define do_for_each_event_file_safe(tr, file) \ + list_for_each_entry(tr, &ftrace_trace_arrays, list) { \ + struct ftrace_event_file *___n; \ + list_for_each_entry_safe(file, ___n, &tr->events, list) + +#define while_for_each_event_file() \ + } + +static struct list_head * trace_get_fields(struct ftrace_event_call *event_call) { if (!event_call->class->get_fields) @@ -44,23 +62,45 @@ trace_get_fields(struct ftrace_event_call *event_call) return event_call->class->get_fields(event_call); } +static struct ftrace_event_field * +__find_event_field(struct list_head *head, char *name) +{ + struct ftrace_event_field *field; + + list_for_each_entry(field, head, link) { + if (!strcmp(field->name, name)) + return field; + } + + return NULL; +} + +struct ftrace_event_field * +trace_find_event_field(struct ftrace_event_call *call, char *name) +{ + struct ftrace_event_field *field; + struct list_head *head; + + field = __find_event_field(&ftrace_common_fields, name); + if (field) + return field; + + head = trace_get_fields(call); + return __find_event_field(head, name); +} + static int __trace_define_field(struct list_head *head, const char *type, const char *name, int offset, int size, int is_signed, int filter_type) { struct ftrace_event_field *field; - field = kzalloc(sizeof(*field), GFP_KERNEL); + field = kmem_cache_alloc(field_cachep, GFP_TRACE); if (!field) goto err; - field->name = kstrdup(name, GFP_KERNEL); - if (!field->name) - goto err; - - field->type = kstrdup(type, GFP_KERNEL); - if (!field->type) - goto err; + field->name = name; + field->type = type; if (filter_type == FILTER_OTHER) field->filter_type = filter_assign_type(type); @@ -76,9 +116,7 @@ static int __trace_define_field(struct list_head *head, const char *type, return 0; err: - if (field) - kfree(field->name); - kfree(field); + kmem_cache_free(field_cachep, field); return -ENOMEM; } @@ -116,12 +154,11 @@ static int trace_define_common_fields(void) __common_field(unsigned char, flags); __common_field(unsigned char, preempt_count); __common_field(int, pid); - __common_field(int, padding); return ret; } -void trace_destroy_fields(struct ftrace_event_call *call) +static void trace_destroy_fields(struct ftrace_event_call *call) { struct ftrace_event_field *field, *next; struct list_head *head; @@ -129,9 +166,7 @@ void trace_destroy_fields(struct ftrace_event_call *call) head = trace_get_fields(call); list_for_each_entry_safe(field, next, head, link) { list_del(&field->link); - kfree(field->type); - kfree(field->name); - kfree(field); + kmem_cache_free(field_cachep, field); } } @@ -150,15 +185,17 @@ EXPORT_SYMBOL_GPL(trace_event_raw_init); int ftrace_event_reg(struct ftrace_event_call *call, enum trace_reg type, void *data) { + struct ftrace_event_file *file = data; + switch (type) { case TRACE_REG_REGISTER: return tracepoint_probe_register(call->name, call->class->probe, - call); + file); case TRACE_REG_UNREGISTER: tracepoint_probe_unregister(call->name, call->class->probe, - call); + file); return 0; #ifdef CONFIG_PERF_EVENTS @@ -184,54 +221,100 @@ EXPORT_SYMBOL_GPL(ftrace_event_reg); void trace_event_enable_cmd_record(bool enable) { - struct ftrace_event_call *call; + struct ftrace_event_file *file; + struct trace_array *tr; mutex_lock(&event_mutex); - list_for_each_entry(call, &ftrace_events, list) { - if (!(call->flags & TRACE_EVENT_FL_ENABLED)) + do_for_each_event_file(tr, file) { + + if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) continue; if (enable) { tracing_start_cmdline_record(); - call->flags |= TRACE_EVENT_FL_RECORDED_CMD; + set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags); } else { tracing_stop_cmdline_record(); - call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD; + clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags); } - } + } while_for_each_event_file(); mutex_unlock(&event_mutex); } -static int ftrace_event_enable_disable(struct ftrace_event_call *call, - int enable) +static int __ftrace_event_enable_disable(struct ftrace_event_file *file, + int enable, int soft_disable) { + struct ftrace_event_call *call = file->event_call; int ret = 0; + int disable; switch (enable) { case 0: - if (call->flags & TRACE_EVENT_FL_ENABLED) { - call->flags &= ~TRACE_EVENT_FL_ENABLED; - if (call->flags & TRACE_EVENT_FL_RECORDED_CMD) { + /* + * When soft_disable is set and enable is cleared, we want + * to clear the SOFT_DISABLED flag but leave the event in the + * state that it was. That is, if the event was enabled and + * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED + * is set we do not want the event to be enabled before we + * clear the bit. + * + * When soft_disable is not set but the SOFT_MODE flag is, + * we do nothing. Do not disable the tracepoint, otherwise + * "soft enable"s (clearing the SOFT_DISABLED bit) wont work. + */ + if (soft_disable) { + disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED; + clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags); + } else + disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE); + + if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) { + clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags); + if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) { tracing_stop_cmdline_record(); - call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD; + clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags); } - call->class->reg(call, TRACE_REG_UNREGISTER, NULL); + call->class->reg(call, TRACE_REG_UNREGISTER, file); } + /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT */ + if (file->flags & FTRACE_EVENT_FL_SOFT_MODE) + set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags); break; case 1: - if (!(call->flags & TRACE_EVENT_FL_ENABLED)) { + /* + * When soft_disable is set and enable is set, we want to + * register the tracepoint for the event, but leave the event + * as is. That means, if the event was already enabled, we do + * nothing (but set SOFT_MODE). If the event is disabled, we + * set SOFT_DISABLED before enabling the event tracepoint, so + * it still seems to be disabled. + */ + if (!soft_disable) + clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags); + else + set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags); + + if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) { + + /* Keep the event disabled, when going to SOFT_MODE. */ + if (soft_disable) + set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags); + if (trace_flags & TRACE_ITER_RECORD_CMD) { tracing_start_cmdline_record(); - call->flags |= TRACE_EVENT_FL_RECORDED_CMD; + set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags); } - ret = call->class->reg(call, TRACE_REG_REGISTER, NULL); + ret = call->class->reg(call, TRACE_REG_REGISTER, file); if (ret) { tracing_stop_cmdline_record(); pr_info("event trace: Could not enable event " "%s\n", call->name); break; } - call->flags |= TRACE_EVENT_FL_ENABLED; + set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags); + + /* WAS_ENABLED gets set but never cleared. */ + call->flags |= TRACE_EVENT_FL_WAS_ENABLED; } break; } @@ -239,13 +322,19 @@ static int ftrace_event_enable_disable(struct ftrace_event_call *call, return ret; } -static void ftrace_clear_events(void) +static int ftrace_event_enable_disable(struct ftrace_event_file *file, + int enable) { - struct ftrace_event_call *call; + return __ftrace_event_enable_disable(file, enable, 0); +} + +static void ftrace_clear_events(struct trace_array *tr) +{ + struct ftrace_event_file *file; mutex_lock(&event_mutex); - list_for_each_entry(call, &ftrace_events, list) { - ftrace_event_enable_disable(call, 0); + list_for_each_entry(file, &tr->events, list) { + ftrace_event_enable_disable(file, 0); } mutex_unlock(&event_mutex); } @@ -258,11 +347,12 @@ static void __put_system(struct event_subsystem *system) if (--system->ref_count) return; + list_del(&system->list); + if (filter) { kfree(filter->filter_string); kfree(filter); } - kfree(system->name); kfree(system); } @@ -272,24 +362,45 @@ static void __get_system(struct event_subsystem *system) system->ref_count++; } -static void put_system(struct event_subsystem *system) +static void __get_system_dir(struct ftrace_subsystem_dir *dir) +{ + WARN_ON_ONCE(dir->ref_count == 0); + dir->ref_count++; + __get_system(dir->subsystem); +} + +static void __put_system_dir(struct ftrace_subsystem_dir *dir) +{ + WARN_ON_ONCE(dir->ref_count == 0); + /* If the subsystem is about to be freed, the dir must be too */ + WARN_ON_ONCE(dir->subsystem->ref_count == 1 && dir->ref_count != 1); + + __put_system(dir->subsystem); + if (!--dir->ref_count) + kfree(dir); +} + +static void put_system(struct ftrace_subsystem_dir *dir) { mutex_lock(&event_mutex); - __put_system(system); + __put_system_dir(dir); mutex_unlock(&event_mutex); } /* * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events. */ -static int __ftrace_set_clr_event(const char *match, const char *sub, - const char *event, int set) +static int __ftrace_set_clr_event(struct trace_array *tr, const char *match, + const char *sub, const char *event, int set) { + struct ftrace_event_file *file; struct ftrace_event_call *call; int ret = -EINVAL; mutex_lock(&event_mutex); - list_for_each_entry(call, &ftrace_events, list) { + list_for_each_entry(file, &tr->events, list) { + + call = file->event_call; if (!call->name || !call->class || !call->class->reg) continue; @@ -308,7 +419,7 @@ static int __ftrace_set_clr_event(const char *match, const char *sub, if (event && strcmp(event, call->name) != 0) continue; - ftrace_event_enable_disable(call, set); + ftrace_event_enable_disable(file, set); ret = 0; } @@ -317,7 +428,7 @@ static int __ftrace_set_clr_event(const char *match, const char *sub, return ret; } -static int ftrace_set_clr_event(char *buf, int set) +static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set) { char *event = NULL, *sub = NULL, *match; @@ -345,7 +456,7 @@ static int ftrace_set_clr_event(char *buf, int set) event = NULL; } - return __ftrace_set_clr_event(match, sub, event, set); + return __ftrace_set_clr_event(tr, match, sub, event, set); } /** @@ -362,7 +473,9 @@ static int ftrace_set_clr_event(char *buf, int set) */ int trace_set_clr_event(const char *system, const char *event, int set) { - return __ftrace_set_clr_event(NULL, system, event, set); + struct trace_array *tr = top_trace_array(); + + return __ftrace_set_clr_event(tr, NULL, system, event, set); } EXPORT_SYMBOL_GPL(trace_set_clr_event); @@ -374,6 +487,8 @@ ftrace_event_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_parser parser; + struct seq_file *m = file->private_data; + struct trace_array *tr = m->private; ssize_t read, ret; if (!cnt) @@ -396,7 +511,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf, parser.buffer[parser.idx] = 0; - ret = ftrace_set_clr_event(parser.buffer + !set, set); + ret = ftrace_set_clr_event(tr, parser.buffer + !set, set); if (ret) goto out_put; } @@ -412,17 +527,20 @@ ftrace_event_write(struct file *file, const char __user *ubuf, static void * t_next(struct seq_file *m, void *v, loff_t *pos) { - struct ftrace_event_call *call = v; + struct ftrace_event_file *file = v; + struct ftrace_event_call *call; + struct trace_array *tr = m->private; (*pos)++; - list_for_each_entry_continue(call, &ftrace_events, list) { + list_for_each_entry_continue(file, &tr->events, list) { + call = file->event_call; /* * The ftrace subsystem is for showing formats only. * They can not be enabled or disabled via the event files. */ if (call->class && call->class->reg) - return call; + return file; } return NULL; @@ -430,30 +548,32 @@ t_next(struct seq_file *m, void *v, loff_t *pos) static void *t_start(struct seq_file *m, loff_t *pos) { - struct ftrace_event_call *call; + struct ftrace_event_file *file; + struct trace_array *tr = m->private; loff_t l; mutex_lock(&event_mutex); - call = list_entry(&ftrace_events, struct ftrace_event_call, list); + file = list_entry(&tr->events, struct ftrace_event_file, list); for (l = 0; l <= *pos; ) { - call = t_next(m, call, &l); - if (!call) + file = t_next(m, file, &l); + if (!file) break; } - return call; + return file; } static void * s_next(struct seq_file *m, void *v, loff_t *pos) { - struct ftrace_event_call *call = v; + struct ftrace_event_file *file = v; + struct trace_array *tr = m->private; (*pos)++; - list_for_each_entry_continue(call, &ftrace_events, list) { - if (call->flags & TRACE_EVENT_FL_ENABLED) - return call; + list_for_each_entry_continue(file, &tr->events, list) { + if (file->flags & FTRACE_EVENT_FL_ENABLED) + return file; } return NULL; @@ -461,23 +581,25 @@ s_next(struct seq_file *m, void *v, loff_t *pos) static void *s_start(struct seq_file *m, loff_t *pos) { - struct ftrace_event_call *call; + struct ftrace_event_file *file; + struct trace_array *tr = m->private; loff_t l; mutex_lock(&event_mutex); - call = list_entry(&ftrace_events, struct ftrace_event_call, list); + file = list_entry(&tr->events, struct ftrace_event_file, list); for (l = 0; l <= *pos; ) { - call = s_next(m, call, &l); - if (!call) + file = s_next(m, file, &l); + if (!file) break; } - return call; + return file; } static int t_show(struct seq_file *m, void *v) { - struct ftrace_event_call *call = v; + struct ftrace_event_file *file = v; + struct ftrace_event_call *call = file->event_call; if (strcmp(call->class->system, TRACE_SYSTEM) != 0) seq_printf(m, "%s:", call->class->system); @@ -495,25 +617,31 @@ static ssize_t event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { - struct ftrace_event_call *call = filp->private_data; + struct ftrace_event_file *file = filp->private_data; char *buf; - if (call->flags & TRACE_EVENT_FL_ENABLED) - buf = "1\n"; - else + if (file->flags & FTRACE_EVENT_FL_ENABLED) { + if (file->flags & FTRACE_EVENT_FL_SOFT_DISABLED) + buf = "0*\n"; + else + buf = "1\n"; + } else buf = "0\n"; - return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); + return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf)); } static ssize_t event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - struct ftrace_event_call *call = filp->private_data; + struct ftrace_event_file *file = filp->private_data; unsigned long val; int ret; + if (!file) + return -EINVAL; + ret = kstrtoul_from_user(ubuf, cnt, 10, &val); if (ret) return ret; @@ -526,7 +654,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, case 0: case 1: mutex_lock(&event_mutex); - ret = ftrace_event_enable_disable(call, val); + ret = ftrace_event_enable_disable(file, val); mutex_unlock(&event_mutex); break; @@ -544,14 +672,18 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { const char set_to_char[4] = { '?', '0', '1', 'X' }; - struct event_subsystem *system = filp->private_data; + struct ftrace_subsystem_dir *dir = filp->private_data; + struct event_subsystem *system = dir->subsystem; struct ftrace_event_call *call; + struct ftrace_event_file *file; + struct trace_array *tr = dir->tr; char buf[2]; int set = 0; int ret; mutex_lock(&event_mutex); - list_for_each_entry(call, &ftrace_events, list) { + list_for_each_entry(file, &tr->events, list) { + call = file->event_call; if (!call->name || !call->class || !call->class->reg) continue; @@ -563,7 +695,7 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, * or if all events or cleared, or if we have * a mixture. */ - set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED)); + set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED)); /* * If we have a mixture, no need to look further. @@ -585,7 +717,8 @@ static ssize_t system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - struct event_subsystem *system = filp->private_data; + struct ftrace_subsystem_dir *dir = filp->private_data; + struct event_subsystem *system = dir->subsystem; const char *name = NULL; unsigned long val; ssize_t ret; @@ -608,7 +741,7 @@ system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, if (system) name = system->name; - ret = __ftrace_set_clr_event(NULL, name, NULL, val); + ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val); if (ret) goto out; @@ -846,43 +979,75 @@ static LIST_HEAD(event_subsystems); static int subsystem_open(struct inode *inode, struct file *filp) { struct event_subsystem *system = NULL; + struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */ + struct trace_array *tr; int ret; - if (!inode->i_private) - goto skip_search; - /* Make sure the system still exists */ mutex_lock(&event_mutex); - list_for_each_entry(system, &event_subsystems, list) { - if (system == inode->i_private) { - /* Don't open systems with no events */ - if (!system->nr_events) { - system = NULL; - break; + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + list_for_each_entry(dir, &tr->systems, list) { + if (dir == inode->i_private) { + /* Don't open systems with no events */ + if (dir->nr_events) { + __get_system_dir(dir); + system = dir->subsystem; + } + goto exit_loop; } - __get_system(system); - break; } } + exit_loop: mutex_unlock(&event_mutex); - if (system != inode->i_private) + if (!system) return -ENODEV; - skip_search: + /* Some versions of gcc think dir can be uninitialized here */ + WARN_ON(!dir); + ret = tracing_open_generic(inode, filp); - if (ret < 0 && system) - put_system(system); + if (ret < 0) + put_system(dir); + + return ret; +} + +static int system_tr_open(struct inode *inode, struct file *filp) +{ + struct ftrace_subsystem_dir *dir; + struct trace_array *tr = inode->i_private; + int ret; + + /* Make a temporary dir that has no system but points to tr */ + dir = kzalloc(sizeof(*dir), GFP_KERNEL); + if (!dir) + return -ENOMEM; + + dir->tr = tr; + + ret = tracing_open_generic(inode, filp); + if (ret < 0) + kfree(dir); + + filp->private_data = dir; return ret; } static int subsystem_release(struct inode *inode, struct file *file) { - struct event_subsystem *system = inode->i_private; + struct ftrace_subsystem_dir *dir = file->private_data; - if (system) - put_system(system); + /* + * If dir->subsystem is NULL, then this is a temporary + * descriptor that was made for a trace_array to enable + * all subsystems. + */ + if (dir->subsystem) + put_system(dir); + else + kfree(dir); return 0; } @@ -891,7 +1056,8 @@ static ssize_t subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { - struct event_subsystem *system = filp->private_data; + struct ftrace_subsystem_dir *dir = filp->private_data; + struct event_subsystem *system = dir->subsystem; struct trace_seq *s; int r; @@ -916,7 +1082,7 @@ static ssize_t subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - struct event_subsystem *system = filp->private_data; + struct ftrace_subsystem_dir *dir = filp->private_data; char *buf; int err; @@ -933,7 +1099,7 @@ subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, } buf[cnt] = '\0'; - err = apply_subsystem_event_filter(system, buf); + err = apply_subsystem_event_filter(dir, buf); free_page((unsigned long) buf); if (err < 0) return err; @@ -1042,30 +1208,35 @@ static const struct file_operations ftrace_system_enable_fops = { .release = subsystem_release, }; +static const struct file_operations ftrace_tr_enable_fops = { + .open = system_tr_open, + .read = system_enable_read, + .write = system_enable_write, + .llseek = default_llseek, + .release = subsystem_release, +}; + static const struct file_operations ftrace_show_header_fops = { .open = tracing_open_generic, .read = show_header, .llseek = default_llseek, }; -static struct dentry *event_trace_events_dir(void) +static int +ftrace_event_open(struct inode *inode, struct file *file, + const struct seq_operations *seq_ops) { - static struct dentry *d_tracer; - static struct dentry *d_events; - - if (d_events) - return d_events; - - d_tracer = tracing_init_dentry(); - if (!d_tracer) - return NULL; + struct seq_file *m; + int ret; - d_events = debugfs_create_dir("events", d_tracer); - if (!d_events) - pr_warning("Could not create debugfs " - "'events' directory\n"); + ret = seq_open(file, seq_ops); + if (ret < 0) + return ret; + m = file->private_data; + /* copy tr over to seq ops */ + m->private = inode->i_private; - return d_events; + return ret; } static int @@ -1073,117 +1244,165 @@ ftrace_event_avail_open(struct inode *inode, struct file *file) { const struct seq_operations *seq_ops = &show_event_seq_ops; - return seq_open(file, seq_ops); + return ftrace_event_open(inode, file, seq_ops); } static int ftrace_event_set_open(struct inode *inode, struct file *file) { const struct seq_operations *seq_ops = &show_set_event_seq_ops; + struct trace_array *tr = inode->i_private; if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) - ftrace_clear_events(); + ftrace_clear_events(tr); - return seq_open(file, seq_ops); + return ftrace_event_open(inode, file, seq_ops); +} + +static struct event_subsystem * +create_new_subsystem(const char *name) +{ + struct event_subsystem *system; + + /* need to create new entry */ + system = kmalloc(sizeof(*system), GFP_KERNEL); + if (!system) + return NULL; + + system->ref_count = 1; + system->name = name; + + system->filter = NULL; + + system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL); + if (!system->filter) + goto out_free; + + list_add(&system->list, &event_subsystems); + + return system; + + out_free: + kfree(system); + return NULL; } static struct dentry * -event_subsystem_dir(const char *name, struct dentry *d_events) +event_subsystem_dir(struct trace_array *tr, const char *name, + struct ftrace_event_file *file, struct dentry *parent) { + struct ftrace_subsystem_dir *dir; struct event_subsystem *system; struct dentry *entry; /* First see if we did not already create this dir */ - list_for_each_entry(system, &event_subsystems, list) { + list_for_each_entry(dir, &tr->systems, list) { + system = dir->subsystem; if (strcmp(system->name, name) == 0) { - system->nr_events++; - return system->entry; + dir->nr_events++; + file->system = dir; + return dir->entry; } } - /* need to create new entry */ - system = kmalloc(sizeof(*system), GFP_KERNEL); - if (!system) { - pr_warning("No memory to create event subsystem %s\n", - name); - return d_events; + /* Now see if the system itself exists. */ + list_for_each_entry(system, &event_subsystems, list) { + if (strcmp(system->name, name) == 0) + break; } + /* Reset system variable when not found */ + if (&system->list == &event_subsystems) + system = NULL; - system->entry = debugfs_create_dir(name, d_events); - if (!system->entry) { - pr_warning("Could not create event subsystem %s\n", - name); - kfree(system); - return d_events; - } + dir = kmalloc(sizeof(*dir), GFP_KERNEL); + if (!dir) + goto out_fail; - system->nr_events = 1; - system->ref_count = 1; - system->name = kstrdup(name, GFP_KERNEL); - if (!system->name) { - debugfs_remove(system->entry); - kfree(system); - return d_events; + if (!system) { + system = create_new_subsystem(name); + if (!system) + goto out_free; + } else + __get_system(system); + + dir->entry = debugfs_create_dir(name, parent); + if (!dir->entry) { + pr_warning("Failed to create system directory %s\n", name); + __put_system(system); + goto out_free; } - list_add(&system->list, &event_subsystems); - - system->filter = NULL; - - system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL); - if (!system->filter) { - pr_warning("Could not allocate filter for subsystem " - "'%s'\n", name); - return system->entry; - } + dir->tr = tr; + dir->ref_count = 1; + dir->nr_events = 1; + dir->subsystem = system; + file->system = dir; - entry = debugfs_create_file("filter", 0644, system->entry, system, + entry = debugfs_create_file("filter", 0644, dir->entry, dir, &ftrace_subsystem_filter_fops); if (!entry) { kfree(system->filter); system->filter = NULL; - pr_warning("Could not create debugfs " - "'%s/filter' entry\n", name); + pr_warning("Could not create debugfs '%s/filter' entry\n", name); } - trace_create_file("enable", 0644, system->entry, system, + trace_create_file("enable", 0644, dir->entry, dir, &ftrace_system_enable_fops); - return system->entry; + list_add(&dir->list, &tr->systems); + + return dir->entry; + + out_free: + kfree(dir); + out_fail: + /* Only print this message if failed on memory allocation */ + if (!dir || !system) + pr_warning("No memory to create event subsystem %s\n", + name); + return NULL; } static int -event_create_dir(struct ftrace_event_call *call, struct dentry *d_events, +event_create_dir(struct dentry *parent, + struct ftrace_event_file *file, const struct file_operations *id, const struct file_operations *enable, const struct file_operations *filter, const struct file_operations *format) { + struct ftrace_event_call *call = file->event_call; + struct trace_array *tr = file->tr; struct list_head *head; + struct dentry *d_events; int ret; /* * If the trace point header did not define TRACE_SYSTEM * then the system would be called "TRACE_SYSTEM". */ - if (strcmp(call->class->system, TRACE_SYSTEM) != 0) - d_events = event_subsystem_dir(call->class->system, d_events); - - call->dir = debugfs_create_dir(call->name, d_events); - if (!call->dir) { - pr_warning("Could not create debugfs " - "'%s' directory\n", call->name); + if (strcmp(call->class->system, TRACE_SYSTEM) != 0) { + d_events = event_subsystem_dir(tr, call->class->system, file, parent); + if (!d_events) + return -ENOMEM; + } else + d_events = parent; + + file->dir = debugfs_create_dir(call->name, d_events); + if (!file->dir) { + pr_warning("Could not create debugfs '%s' directory\n", + call->name); return -1; } if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) - trace_create_file("enable", 0644, call->dir, call, + trace_create_file("enable", 0644, file->dir, file, enable); #ifdef CONFIG_PERF_EVENTS if (call->event.type && call->class->reg) - trace_create_file("id", 0444, call->dir, call, + trace_create_file("id", 0444, file->dir, call, id); #endif @@ -1197,23 +1416,76 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events, if (ret < 0) { pr_warning("Could not initialize trace point" " events/%s\n", call->name); - return ret; + return -1; } } - trace_create_file("filter", 0644, call->dir, call, + trace_create_file("filter", 0644, file->dir, call, filter); - trace_create_file("format", 0444, call->dir, call, + trace_create_file("format", 0444, file->dir, call, format); return 0; } +static void remove_subsystem(struct ftrace_subsystem_dir *dir) +{ + if (!dir) + return; + + if (!--dir->nr_events) { + debugfs_remove_recursive(dir->entry); + list_del(&dir->list); + __put_system_dir(dir); + } +} + +static void remove_event_from_tracers(struct ftrace_event_call *call) +{ + struct ftrace_event_file *file; + struct trace_array *tr; + + do_for_each_event_file_safe(tr, file) { + + if (file->event_call != call) + continue; + + list_del(&file->list); + debugfs_remove_recursive(file->dir); + remove_subsystem(file->system); + kmem_cache_free(file_cachep, file); + + /* + * The do_for_each_event_file_safe() is + * a double loop. After finding the call for this + * trace_array, we use break to jump to the next + * trace_array. + */ + break; + } while_for_each_event_file(); +} + static void event_remove(struct ftrace_event_call *call) { - ftrace_event_enable_disable(call, 0); + struct trace_array *tr; + struct ftrace_event_file *file; + + do_for_each_event_file(tr, file) { + if (file->event_call != call) + continue; + ftrace_event_enable_disable(file, 0); + /* + * The do_for_each_event_file() is + * a double loop. After finding the call for this + * trace_array, we use break to jump to the next + * trace_array. + */ + break; + } while_for_each_event_file(); + if (call->event.funcs) __unregister_ftrace_event(&call->event); + remove_event_from_tracers(call); list_del(&call->list); } @@ -1235,82 +1507,99 @@ static int event_init(struct ftrace_event_call *call) } static int -__trace_add_event_call(struct ftrace_event_call *call, struct module *mod, - const struct file_operations *id, - const struct file_operations *enable, - const struct file_operations *filter, - const struct file_operations *format) +__register_event(struct ftrace_event_call *call, struct module *mod) { - struct dentry *d_events; int ret; ret = event_init(call); if (ret < 0) return ret; - d_events = event_trace_events_dir(); - if (!d_events) - return -ENOENT; - - ret = event_create_dir(call, d_events, id, enable, filter, format); - if (!ret) - list_add(&call->list, &ftrace_events); + list_add(&call->list, &ftrace_events); call->mod = mod; - return ret; + return 0; +} + +/* Add an event to a trace directory */ +static int +__trace_add_new_event(struct ftrace_event_call *call, + struct trace_array *tr, + const struct file_operations *id, + const struct file_operations *enable, + const struct file_operations *filter, + const struct file_operations *format) +{ + struct ftrace_event_file *file; + + file = kmem_cache_alloc(file_cachep, GFP_TRACE); + if (!file) + return -ENOMEM; + + file->event_call = call; + file->tr = tr; + list_add(&file->list, &tr->events); + + return event_create_dir(tr->event_dir, file, id, enable, filter, format); } +/* + * Just create a decriptor for early init. A descriptor is required + * for enabling events at boot. We want to enable events before + * the filesystem is initialized. + */ +static __init int +__trace_early_add_new_event(struct ftrace_event_call *call, + struct trace_array *tr) +{ + struct ftrace_event_file *file; + + file = kmem_cache_alloc(file_cachep, GFP_TRACE); + if (!file) + return -ENOMEM; + + file->event_call = call; + file->tr = tr; + list_add(&file->list, &tr->events); + + return 0; +} + +struct ftrace_module_file_ops; +static void __add_event_to_tracers(struct ftrace_event_call *call, + struct ftrace_module_file_ops *file_ops); + /* Add an additional event_call dynamically */ int trace_add_event_call(struct ftrace_event_call *call) { int ret; mutex_lock(&event_mutex); - ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops, - &ftrace_enable_fops, - &ftrace_event_filter_fops, - &ftrace_event_format_fops); - mutex_unlock(&event_mutex); - return ret; -} -static void remove_subsystem_dir(const char *name) -{ - struct event_subsystem *system; - - if (strcmp(name, TRACE_SYSTEM) == 0) - return; + ret = __register_event(call, NULL); + if (ret >= 0) + __add_event_to_tracers(call, NULL); - list_for_each_entry(system, &event_subsystems, list) { - if (strcmp(system->name, name) == 0) { - if (!--system->nr_events) { - debugfs_remove_recursive(system->entry); - list_del(&system->list); - __put_system(system); - } - break; - } - } + mutex_unlock(&event_mutex); + return ret; } /* - * Must be called under locking both of event_mutex and trace_event_mutex. + * Must be called under locking both of event_mutex and trace_event_sem. */ static void __trace_remove_event_call(struct ftrace_event_call *call) { event_remove(call); trace_destroy_fields(call); destroy_preds(call); - debugfs_remove_recursive(call->dir); - remove_subsystem_dir(call->class->system); } /* Remove an event_call */ void trace_remove_event_call(struct ftrace_event_call *call) { mutex_lock(&event_mutex); - down_write(&trace_event_mutex); + down_write(&trace_event_sem); __trace_remove_event_call(call); - up_write(&trace_event_mutex); + up_write(&trace_event_sem); mutex_unlock(&event_mutex); } @@ -1337,6 +1626,26 @@ struct ftrace_module_file_ops { }; static struct ftrace_module_file_ops * +find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod) +{ + /* + * As event_calls are added in groups by module, + * when we find one file_ops, we don't need to search for + * each call in that module, as the rest should be the + * same. Only search for a new one if the last one did + * not match. + */ + if (file_ops && mod == file_ops->mod) + return file_ops; + + list_for_each_entry(file_ops, &ftrace_module_file_list, list) { + if (file_ops->mod == mod) + return file_ops; + } + return NULL; +} + +static struct ftrace_module_file_ops * trace_create_file_ops(struct module *mod) { struct ftrace_module_file_ops *file_ops; @@ -1387,9 +1696,8 @@ static void trace_module_add_events(struct module *mod) return; for_each_event(call, start, end) { - __trace_add_event_call(*call, mod, - &file_ops->id, &file_ops->enable, - &file_ops->filter, &file_ops->format); + __register_event(*call, mod); + __add_event_to_tracers(*call, file_ops); } } @@ -1397,12 +1705,13 @@ static void trace_module_remove_events(struct module *mod) { struct ftrace_module_file_ops *file_ops; struct ftrace_event_call *call, *p; - bool found = false; + bool clear_trace = false; - down_write(&trace_event_mutex); + down_write(&trace_event_sem); list_for_each_entry_safe(call, p, &ftrace_events, list) { if (call->mod == mod) { - found = true; + if (call->flags & TRACE_EVENT_FL_WAS_ENABLED) + clear_trace = true; __trace_remove_event_call(call); } } @@ -1416,14 +1725,18 @@ static void trace_module_remove_events(struct module *mod) list_del(&file_ops->list); kfree(file_ops); } + up_write(&trace_event_sem); /* * It is safest to reset the ring buffer if the module being unloaded - * registered any events. + * registered any events that were used. The only worry is if + * a new module gets loaded, and takes on the same id as the events + * of this module. When printing out the buffer, traced events left + * over from this module may be passed to the new module events and + * unexpected results may occur. */ - if (found) - tracing_reset_current_online_cpus(); - up_write(&trace_event_mutex); + if (clear_trace) + tracing_reset_all_online_cpus(); } static int trace_module_notify(struct notifier_block *self, @@ -1444,14 +1757,433 @@ static int trace_module_notify(struct notifier_block *self, return 0; } + +static int +__trace_add_new_mod_event(struct ftrace_event_call *call, + struct trace_array *tr, + struct ftrace_module_file_ops *file_ops) +{ + return __trace_add_new_event(call, tr, + &file_ops->id, &file_ops->enable, + &file_ops->filter, &file_ops->format); +} + #else -static int trace_module_notify(struct notifier_block *self, - unsigned long val, void *data) +static inline struct ftrace_module_file_ops * +find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod) +{ + return NULL; +} +static inline int trace_module_notify(struct notifier_block *self, + unsigned long val, void *data) { return 0; } +static inline int +__trace_add_new_mod_event(struct ftrace_event_call *call, + struct trace_array *tr, + struct ftrace_module_file_ops *file_ops) +{ + return -ENODEV; +} #endif /* CONFIG_MODULES */ +/* Create a new event directory structure for a trace directory. */ +static void +__trace_add_event_dirs(struct trace_array *tr) +{ + struct ftrace_module_file_ops *file_ops = NULL; + struct ftrace_event_call *call; + int ret; + + list_for_each_entry(call, &ftrace_events, list) { + if (call->mod) { + /* + * Directories for events by modules need to + * keep module ref counts when opened (as we don't + * want the module to disappear when reading one + * of these files). The file_ops keep account of + * the module ref count. + */ + file_ops = find_ftrace_file_ops(file_ops, call->mod); + if (!file_ops) + continue; /* Warn? */ + ret = __trace_add_new_mod_event(call, tr, file_ops); + if (ret < 0) + pr_warning("Could not create directory for event %s\n", + call->name); + continue; + } + ret = __trace_add_new_event(call, tr, + &ftrace_event_id_fops, + &ftrace_enable_fops, + &ftrace_event_filter_fops, + &ftrace_event_format_fops); + if (ret < 0) + pr_warning("Could not create directory for event %s\n", + call->name); + } +} + +#ifdef CONFIG_DYNAMIC_FTRACE + +/* Avoid typos */ +#define ENABLE_EVENT_STR "enable_event" +#define DISABLE_EVENT_STR "disable_event" + +struct event_probe_data { + struct ftrace_event_file *file; + unsigned long count; + int ref; + bool enable; +}; + +static struct ftrace_event_file * +find_event_file(struct trace_array *tr, const char *system, const char *event) +{ + struct ftrace_event_file *file; + struct ftrace_event_call *call; + + list_for_each_entry(file, &tr->events, list) { + + call = file->event_call; + + if (!call->name || !call->class || !call->class->reg) + continue; + + if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) + continue; + + if (strcmp(event, call->name) == 0 && + strcmp(system, call->class->system) == 0) + return file; + } + return NULL; +} + +static void +event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data) +{ + struct event_probe_data **pdata = (struct event_probe_data **)_data; + struct event_probe_data *data = *pdata; + + if (!data) + return; + + if (data->enable) + clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags); + else + set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags); +} + +static void +event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data) +{ + struct event_probe_data **pdata = (struct event_probe_data **)_data; + struct event_probe_data *data = *pdata; + + if (!data) + return; + + if (!data->count) + return; + + /* Skip if the event is in a state we want to switch to */ + if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED)) + return; + + if (data->count != -1) + (data->count)--; + + event_enable_probe(ip, parent_ip, _data); +} + +static int +event_enable_print(struct seq_file *m, unsigned long ip, + struct ftrace_probe_ops *ops, void *_data) +{ + struct event_probe_data *data = _data; + + seq_printf(m, "%ps:", (void *)ip); + + seq_printf(m, "%s:%s:%s", + data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR, + data->file->event_call->class->system, + data->file->event_call->name); + + if (data->count == -1) + seq_printf(m, ":unlimited\n"); + else + seq_printf(m, ":count=%ld\n", data->count); + + return 0; +} + +static int +event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip, + void **_data) +{ + struct event_probe_data **pdata = (struct event_probe_data **)_data; + struct event_probe_data *data = *pdata; + + data->ref++; + return 0; +} + +static void +event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip, + void **_data) +{ + struct event_probe_data **pdata = (struct event_probe_data **)_data; + struct event_probe_data *data = *pdata; + + if (WARN_ON_ONCE(data->ref <= 0)) + return; + + data->ref--; + if (!data->ref) { + /* Remove the SOFT_MODE flag */ + __ftrace_event_enable_disable(data->file, 0, 1); + module_put(data->file->event_call->mod); + kfree(data); + } + *pdata = NULL; +} + +static struct ftrace_probe_ops event_enable_probe_ops = { + .func = event_enable_probe, + .print = event_enable_print, + .init = event_enable_init, + .free = event_enable_free, +}; + +static struct ftrace_probe_ops event_enable_count_probe_ops = { + .func = event_enable_count_probe, + .print = event_enable_print, + .init = event_enable_init, + .free = event_enable_free, +}; + +static struct ftrace_probe_ops event_disable_probe_ops = { + .func = event_enable_probe, + .print = event_enable_print, + .init = event_enable_init, + .free = event_enable_free, +}; + +static struct ftrace_probe_ops event_disable_count_probe_ops = { + .func = event_enable_count_probe, + .print = event_enable_print, + .init = event_enable_init, + .free = event_enable_free, +}; + +static int +event_enable_func(struct ftrace_hash *hash, + char *glob, char *cmd, char *param, int enabled) +{ + struct trace_array *tr = top_trace_array(); + struct ftrace_event_file *file; + struct ftrace_probe_ops *ops; + struct event_probe_data *data; + const char *system; + const char *event; + char *number; + bool enable; + int ret; + + /* hash funcs only work with set_ftrace_filter */ + if (!enabled) + return -EINVAL; + + if (!param) + return -EINVAL; + + system = strsep(¶m, ":"); + if (!param) + return -EINVAL; + + event = strsep(¶m, ":"); + + mutex_lock(&event_mutex); + + ret = -EINVAL; + file = find_event_file(tr, system, event); + if (!file) + goto out; + + enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; + + if (enable) + ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops; + else + ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops; + + if (glob[0] == '!') { + unregister_ftrace_function_probe_func(glob+1, ops); + ret = 0; + goto out; + } + + ret = -ENOMEM; + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + goto out; + + data->enable = enable; + data->count = -1; + data->file = file; + + if (!param) + goto out_reg; + + number = strsep(¶m, ":"); + + ret = -EINVAL; + if (!strlen(number)) + goto out_free; + + /* + * We use the callback data field (which is a pointer) + * as our counter. + */ + ret = kstrtoul(number, 0, &data->count); + if (ret) + goto out_free; + + out_reg: + /* Don't let event modules unload while probe registered */ + ret = try_module_get(file->event_call->mod); + if (!ret) + goto out_free; + + ret = __ftrace_event_enable_disable(file, 1, 1); + if (ret < 0) + goto out_put; + ret = register_ftrace_function_probe(glob, ops, data); + if (!ret) + goto out_disable; + out: + mutex_unlock(&event_mutex); + return ret; + + out_disable: + __ftrace_event_enable_disable(file, 0, 1); + out_put: + module_put(file->event_call->mod); + out_free: + kfree(data); + goto out; +} + +static struct ftrace_func_command event_enable_cmd = { + .name = ENABLE_EVENT_STR, + .func = event_enable_func, +}; + +static struct ftrace_func_command event_disable_cmd = { + .name = DISABLE_EVENT_STR, + .func = event_enable_func, +}; + +static __init int register_event_cmds(void) +{ + int ret; + + ret = register_ftrace_command(&event_enable_cmd); + if (WARN_ON(ret < 0)) + return ret; + ret = register_ftrace_command(&event_disable_cmd); + if (WARN_ON(ret < 0)) + unregister_ftrace_command(&event_enable_cmd); + return ret; +} +#else +static inline int register_event_cmds(void) { return 0; } +#endif /* CONFIG_DYNAMIC_FTRACE */ + +/* + * The top level array has already had its ftrace_event_file + * descriptors created in order to allow for early events to + * be recorded. This function is called after the debugfs has been + * initialized, and we now have to create the files associated + * to the events. + */ +static __init void +__trace_early_add_event_dirs(struct trace_array *tr) +{ + struct ftrace_event_file *file; + int ret; + + + list_for_each_entry(file, &tr->events, list) { + ret = event_create_dir(tr->event_dir, file, + &ftrace_event_id_fops, + &ftrace_enable_fops, + &ftrace_event_filter_fops, + &ftrace_event_format_fops); + if (ret < 0) + pr_warning("Could not create directory for event %s\n", + file->event_call->name); + } +} + +/* + * For early boot up, the top trace array requires to have + * a list of events that can be enabled. This must be done before + * the filesystem is set up in order to allow events to be traced + * early. + */ +static __init void +__trace_early_add_events(struct trace_array *tr) +{ + struct ftrace_event_call *call; + int ret; + + list_for_each_entry(call, &ftrace_events, list) { + /* Early boot up should not have any modules loaded */ + if (WARN_ON_ONCE(call->mod)) + continue; + + ret = __trace_early_add_new_event(call, tr); + if (ret < 0) + pr_warning("Could not create early event %s\n", + call->name); + } +} + +/* Remove the event directory structure for a trace directory. */ +static void +__trace_remove_event_dirs(struct trace_array *tr) +{ + struct ftrace_event_file *file, *next; + + list_for_each_entry_safe(file, next, &tr->events, list) { + list_del(&file->list); + debugfs_remove_recursive(file->dir); + remove_subsystem(file->system); + kmem_cache_free(file_cachep, file); + } +} + +static void +__add_event_to_tracers(struct ftrace_event_call *call, + struct ftrace_module_file_ops *file_ops) +{ + struct trace_array *tr; + + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (file_ops) + __trace_add_new_mod_event(call, tr, file_ops); + else + __trace_add_new_event(call, tr, + &ftrace_event_id_fops, + &ftrace_enable_fops, + &ftrace_event_filter_fops, + &ftrace_event_format_fops); + } +} + static struct notifier_block trace_module_nb = { .notifier_call = trace_module_notify, .priority = 0, @@ -1465,15 +2197,135 @@ static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata; static __init int setup_trace_event(char *str) { strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE); - ring_buffer_expanded = 1; - tracing_selftest_disabled = 1; + ring_buffer_expanded = true; + tracing_selftest_disabled = true; return 1; } __setup("trace_event=", setup_trace_event); +/* Expects to have event_mutex held when called */ +static int +create_event_toplevel_files(struct dentry *parent, struct trace_array *tr) +{ + struct dentry *d_events; + struct dentry *entry; + + entry = debugfs_create_file("set_event", 0644, parent, + tr, &ftrace_set_event_fops); + if (!entry) { + pr_warning("Could not create debugfs 'set_event' entry\n"); + return -ENOMEM; + } + + d_events = debugfs_create_dir("events", parent); + if (!d_events) { + pr_warning("Could not create debugfs 'events' directory\n"); + return -ENOMEM; + } + + /* ring buffer internal formats */ + trace_create_file("header_page", 0444, d_events, + ring_buffer_print_page_header, + &ftrace_show_header_fops); + + trace_create_file("header_event", 0444, d_events, + ring_buffer_print_entry_header, + &ftrace_show_header_fops); + + trace_create_file("enable", 0644, d_events, + tr, &ftrace_tr_enable_fops); + + tr->event_dir = d_events; + + return 0; +} + +/** + * event_trace_add_tracer - add a instance of a trace_array to events + * @parent: The parent dentry to place the files/directories for events in + * @tr: The trace array associated with these events + * + * When a new instance is created, it needs to set up its events + * directory, as well as other files associated with events. It also + * creates the event hierachry in the @parent/events directory. + * + * Returns 0 on success. + */ +int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr) +{ + int ret; + + mutex_lock(&event_mutex); + + ret = create_event_toplevel_files(parent, tr); + if (ret) + goto out_unlock; + + down_write(&trace_event_sem); + __trace_add_event_dirs(tr); + up_write(&trace_event_sem); + + out_unlock: + mutex_unlock(&event_mutex); + + return ret; +} + +/* + * The top trace array already had its file descriptors created. + * Now the files themselves need to be created. + */ +static __init int +early_event_add_tracer(struct dentry *parent, struct trace_array *tr) +{ + int ret; + + mutex_lock(&event_mutex); + + ret = create_event_toplevel_files(parent, tr); + if (ret) + goto out_unlock; + + down_write(&trace_event_sem); + __trace_early_add_event_dirs(tr); + up_write(&trace_event_sem); + + out_unlock: + mutex_unlock(&event_mutex); + + return ret; +} + +int event_trace_del_tracer(struct trace_array *tr) +{ + /* Disable any running events */ + __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0); + + mutex_lock(&event_mutex); + + down_write(&trace_event_sem); + __trace_remove_event_dirs(tr); + debugfs_remove_recursive(tr->event_dir); + up_write(&trace_event_sem); + + tr->event_dir = NULL; + + mutex_unlock(&event_mutex); + + return 0; +} + +static __init int event_trace_memsetup(void) +{ + field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC); + file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC); + return 0; +} + static __init int event_trace_enable(void) { + struct trace_array *tr = top_trace_array(); struct ftrace_event_call **iter, *call; char *buf = bootup_event_buf; char *token; @@ -1487,6 +2339,14 @@ static __init int event_trace_enable(void) list_add(&call->list, &ftrace_events); } + /* + * We need the top trace array to have a working set of trace + * points at early init, before the debug files and directories + * are created. Create the file entries now, and attach them + * to the actual file dentries later. + */ + __trace_early_add_events(tr); + while (true) { token = strsep(&buf, ","); @@ -1495,73 +2355,43 @@ static __init int event_trace_enable(void) if (!*token) continue; - ret = ftrace_set_clr_event(token, 1); + ret = ftrace_set_clr_event(tr, token, 1); if (ret) pr_warn("Failed to enable trace event: %s\n", token); } trace_printk_start_comm(); + register_event_cmds(); + return 0; } static __init int event_trace_init(void) { - struct ftrace_event_call *call; + struct trace_array *tr; struct dentry *d_tracer; struct dentry *entry; - struct dentry *d_events; int ret; + tr = top_trace_array(); + d_tracer = tracing_init_dentry(); if (!d_tracer) return 0; entry = debugfs_create_file("available_events", 0444, d_tracer, - NULL, &ftrace_avail_fops); + tr, &ftrace_avail_fops); if (!entry) pr_warning("Could not create debugfs " "'available_events' entry\n"); - entry = debugfs_create_file("set_event", 0644, d_tracer, - NULL, &ftrace_set_event_fops); - if (!entry) - pr_warning("Could not create debugfs " - "'set_event' entry\n"); - - d_events = event_trace_events_dir(); - if (!d_events) - return 0; - - /* ring buffer internal formats */ - trace_create_file("header_page", 0444, d_events, - ring_buffer_print_page_header, - &ftrace_show_header_fops); - - trace_create_file("header_event", 0444, d_events, - ring_buffer_print_entry_header, - &ftrace_show_header_fops); - - trace_create_file("enable", 0644, d_events, - NULL, &ftrace_system_enable_fops); - if (trace_define_common_fields()) pr_warning("tracing: Failed to allocate common fields"); - /* - * Early initialization already enabled ftrace event. - * Now it's only necessary to create the event directory. - */ - list_for_each_entry(call, &ftrace_events, list) { - - ret = event_create_dir(call, d_events, - &ftrace_event_id_fops, - &ftrace_enable_fops, - &ftrace_event_filter_fops, - &ftrace_event_format_fops); - if (ret < 0) - event_remove(call); - } + ret = early_event_add_tracer(d_tracer, tr); + if (ret) + return ret; ret = register_module_notifier(&trace_module_nb); if (ret) @@ -1569,6 +2399,7 @@ static __init int event_trace_init(void) return 0; } +early_initcall(event_trace_memsetup); core_initcall(event_trace_enable); fs_initcall(event_trace_init); @@ -1628,13 +2459,20 @@ static __init void event_test_stuff(void) */ static __init void event_trace_self_tests(void) { + struct ftrace_subsystem_dir *dir; + struct ftrace_event_file *file; struct ftrace_event_call *call; struct event_subsystem *system; + struct trace_array *tr; int ret; + tr = top_trace_array(); + pr_info("Running tests on trace events:\n"); - list_for_each_entry(call, &ftrace_events, list) { + list_for_each_entry(file, &tr->events, list) { + + call = file->event_call; /* Only test those that have a probe */ if (!call->class || !call->class->probe) @@ -1658,15 +2496,15 @@ static __init void event_trace_self_tests(void) * If an event is already enabled, someone is using * it and the self test should not be on. */ - if (call->flags & TRACE_EVENT_FL_ENABLED) { + if (file->flags & FTRACE_EVENT_FL_ENABLED) { pr_warning("Enabled event during self test!\n"); WARN_ON_ONCE(1); continue; } - ftrace_event_enable_disable(call, 1); + ftrace_event_enable_disable(file, 1); event_test_stuff(); - ftrace_event_enable_disable(call, 0); + ftrace_event_enable_disable(file, 0); pr_cont("OK\n"); } @@ -1675,7 +2513,9 @@ static __init void event_trace_self_tests(void) pr_info("Running tests on trace event systems:\n"); - list_for_each_entry(system, &event_subsystems, list) { + list_for_each_entry(dir, &tr->systems, list) { + + system = dir->subsystem; /* the ftrace system is special, skip it */ if (strcmp(system->name, "ftrace") == 0) @@ -1683,7 +2523,7 @@ static __init void event_trace_self_tests(void) pr_info("Testing event system %s: ", system->name); - ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1); + ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1); if (WARN_ON_ONCE(ret)) { pr_warning("error enabling system %s\n", system->name); @@ -1692,7 +2532,7 @@ static __init void event_trace_self_tests(void) event_test_stuff(); - ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0); + ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0); if (WARN_ON_ONCE(ret)) { pr_warning("error disabling system %s\n", system->name); @@ -1707,7 +2547,7 @@ static __init void event_trace_self_tests(void) pr_info("Running tests on all trace events:\n"); pr_info("Testing all events: "); - ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1); + ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1); if (WARN_ON_ONCE(ret)) { pr_warning("error enabling all events\n"); return; @@ -1716,7 +2556,7 @@ static __init void event_trace_self_tests(void) event_test_stuff(); /* reset sysname */ - ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0); + ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0); if (WARN_ON_ONCE(ret)) { pr_warning("error disabling all events\n"); return; diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index e5b0ca8b8d4d..a6361178de5a 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -658,33 +658,6 @@ void print_subsystem_event_filter(struct event_subsystem *system, mutex_unlock(&event_mutex); } -static struct ftrace_event_field * -__find_event_field(struct list_head *head, char *name) -{ - struct ftrace_event_field *field; - - list_for_each_entry(field, head, link) { - if (!strcmp(field->name, name)) - return field; - } - - return NULL; -} - -static struct ftrace_event_field * -find_event_field(struct ftrace_event_call *call, char *name) -{ - struct ftrace_event_field *field; - struct list_head *head; - - field = __find_event_field(&ftrace_common_fields, name); - if (field) - return field; - - head = trace_get_fields(call); - return __find_event_field(head, name); -} - static int __alloc_pred_stack(struct pred_stack *stack, int n_preds) { stack->preds = kcalloc(n_preds + 1, sizeof(*stack->preds), GFP_KERNEL); @@ -1337,7 +1310,7 @@ static struct filter_pred *create_pred(struct filter_parse_state *ps, return NULL; } - field = find_event_field(call, operand1); + field = trace_find_event_field(call, operand1); if (!field) { parse_error(ps, FILT_ERR_FIELD_NOT_FOUND, 0); return NULL; @@ -1907,16 +1880,17 @@ out_unlock: return err; } -int apply_subsystem_event_filter(struct event_subsystem *system, +int apply_subsystem_event_filter(struct ftrace_subsystem_dir *dir, char *filter_string) { + struct event_subsystem *system = dir->subsystem; struct event_filter *filter; int err = 0; mutex_lock(&event_mutex); /* Make sure the system still has events */ - if (!system->nr_events) { + if (!dir->nr_events) { err = -ENODEV; goto out_unlock; } diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index e039906b037d..d21a74670088 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -129,7 +129,7 @@ static void __always_unused ____ftrace_check_##name(void) \ #undef FTRACE_ENTRY #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter) \ -int \ +static int __init \ ftrace_define_fields_##name(struct ftrace_event_call *event_call) \ { \ struct struct_name field; \ @@ -168,7 +168,7 @@ ftrace_define_fields_##name(struct ftrace_event_call *event_call) \ #define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, filter,\ regfn) \ \ -struct ftrace_event_class event_class_ftrace_##call = { \ +struct ftrace_event_class __refdata event_class_ftrace_##call = { \ .system = __stringify(TRACE_SYSTEM), \ .define_fields = ftrace_define_fields_##call, \ .fields = LIST_HEAD_INIT(event_class_ftrace_##call.fields),\ diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 8e3ad8082ab7..c4d6d7191988 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -28,7 +28,7 @@ static void tracing_stop_function_trace(void); static int function_trace_init(struct trace_array *tr) { func_trace = tr; - tr->cpu = get_cpu(); + tr->trace_buffer.cpu = get_cpu(); put_cpu(); tracing_start_cmdline_record(); @@ -44,35 +44,7 @@ static void function_trace_reset(struct trace_array *tr) static void function_trace_start(struct trace_array *tr) { - tracing_reset_online_cpus(tr); -} - -static void -function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *pt_regs) -{ - struct trace_array *tr = func_trace; - struct trace_array_cpu *data; - unsigned long flags; - long disabled; - int cpu; - int pc; - - if (unlikely(!ftrace_function_enabled)) - return; - - pc = preempt_count(); - preempt_disable_notrace(); - local_save_flags(flags); - cpu = raw_smp_processor_id(); - data = tr->data[cpu]; - disabled = atomic_inc_return(&data->disabled); - - if (likely(disabled == 1)) - trace_function(tr, ip, parent_ip, flags, pc); - - atomic_dec(&data->disabled); - preempt_enable_notrace(); + tracing_reset_online_cpus(&tr->trace_buffer); } /* Our option */ @@ -85,34 +57,34 @@ static struct tracer_flags func_flags; static void function_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *pt_regs) - { struct trace_array *tr = func_trace; struct trace_array_cpu *data; unsigned long flags; - long disabled; + int bit; int cpu; int pc; if (unlikely(!ftrace_function_enabled)) return; - /* - * Need to use raw, since this must be called before the - * recursive protection is performed. - */ - local_irq_save(flags); - cpu = raw_smp_processor_id(); - data = tr->data[cpu]; - disabled = atomic_inc_return(&data->disabled); + pc = preempt_count(); + preempt_disable_notrace(); - if (likely(disabled == 1)) { - pc = preempt_count(); + bit = trace_test_and_set_recursion(TRACE_FTRACE_START, TRACE_FTRACE_MAX); + if (bit < 0) + goto out; + + cpu = smp_processor_id(); + data = per_cpu_ptr(tr->trace_buffer.data, cpu); + if (!atomic_read(&data->disabled)) { + local_save_flags(flags); trace_function(tr, ip, parent_ip, flags, pc); } + trace_clear_recursion(bit); - atomic_dec(&data->disabled); - local_irq_restore(flags); + out: + preempt_enable_notrace(); } static void @@ -135,7 +107,7 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip, */ local_irq_save(flags); cpu = raw_smp_processor_id(); - data = tr->data[cpu]; + data = per_cpu_ptr(tr->trace_buffer.data, cpu); disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) { @@ -185,11 +157,6 @@ static void tracing_start_function_trace(void) { ftrace_function_enabled = 0; - if (trace_flags & TRACE_ITER_PREEMPTONLY) - trace_ops.func = function_trace_call_preempt_only; - else - trace_ops.func = function_trace_call; - if (func_flags.val & TRACE_FUNC_OPT_STACK) register_ftrace_function(&trace_stack_ops); else @@ -247,66 +214,89 @@ static struct tracer function_trace __read_mostly = }; #ifdef CONFIG_DYNAMIC_FTRACE -static void -ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data) +static int update_count(void **data) { - long *count = (long *)data; - - if (tracing_is_on()) - return; + unsigned long *count = (long *)data; if (!*count) - return; + return 0; if (*count != -1) (*count)--; - tracing_on(); + return 1; } static void -ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data) +ftrace_traceon_count(unsigned long ip, unsigned long parent_ip, void **data) { - long *count = (long *)data; + if (tracing_is_on()) + return; + + if (update_count(data)) + tracing_on(); +} +static void +ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip, void **data) +{ if (!tracing_is_on()) return; - if (!*count) + if (update_count(data)) + tracing_off(); +} + +static void +ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data) +{ + if (tracing_is_on()) return; - if (*count != -1) - (*count)--; + tracing_on(); +} + +static void +ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data) +{ + if (!tracing_is_on()) + return; tracing_off(); } -static int -ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip, - struct ftrace_probe_ops *ops, void *data); +/* + * Skip 4: + * ftrace_stacktrace() + * function_trace_probe_call() + * ftrace_ops_list_func() + * ftrace_call() + */ +#define STACK_SKIP 4 -static struct ftrace_probe_ops traceon_probe_ops = { - .func = ftrace_traceon, - .print = ftrace_trace_onoff_print, -}; +static void +ftrace_stacktrace(unsigned long ip, unsigned long parent_ip, void **data) +{ + trace_dump_stack(STACK_SKIP); +} -static struct ftrace_probe_ops traceoff_probe_ops = { - .func = ftrace_traceoff, - .print = ftrace_trace_onoff_print, -}; +static void +ftrace_stacktrace_count(unsigned long ip, unsigned long parent_ip, void **data) +{ + if (!tracing_is_on()) + return; + + if (update_count(data)) + trace_dump_stack(STACK_SKIP); +} static int -ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip, - struct ftrace_probe_ops *ops, void *data) +ftrace_probe_print(const char *name, struct seq_file *m, + unsigned long ip, void *data) { long count = (long)data; - seq_printf(m, "%ps:", (void *)ip); - - if (ops == &traceon_probe_ops) - seq_printf(m, "traceon"); - else - seq_printf(m, "traceoff"); + seq_printf(m, "%ps:%s", (void *)ip, name); if (count == -1) seq_printf(m, ":unlimited\n"); @@ -317,26 +307,61 @@ ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip, } static int -ftrace_trace_onoff_unreg(char *glob, char *cmd, char *param) +ftrace_traceon_print(struct seq_file *m, unsigned long ip, + struct ftrace_probe_ops *ops, void *data) { - struct ftrace_probe_ops *ops; - - /* we register both traceon and traceoff to this callback */ - if (strcmp(cmd, "traceon") == 0) - ops = &traceon_probe_ops; - else - ops = &traceoff_probe_ops; + return ftrace_probe_print("traceon", m, ip, data); +} - unregister_ftrace_function_probe_func(glob, ops); +static int +ftrace_traceoff_print(struct seq_file *m, unsigned long ip, + struct ftrace_probe_ops *ops, void *data) +{ + return ftrace_probe_print("traceoff", m, ip, data); +} - return 0; +static int +ftrace_stacktrace_print(struct seq_file *m, unsigned long ip, + struct ftrace_probe_ops *ops, void *data) +{ + return ftrace_probe_print("stacktrace", m, ip, data); } +static struct ftrace_probe_ops traceon_count_probe_ops = { + .func = ftrace_traceon_count, + .print = ftrace_traceon_print, +}; + +static struct ftrace_probe_ops traceoff_count_probe_ops = { + .func = ftrace_traceoff_count, + .print = ftrace_traceoff_print, +}; + +static struct ftrace_probe_ops stacktrace_count_probe_ops = { + .func = ftrace_stacktrace_count, + .print = ftrace_stacktrace_print, +}; + +static struct ftrace_probe_ops traceon_probe_ops = { + .func = ftrace_traceon, + .print = ftrace_traceon_print, +}; + +static struct ftrace_probe_ops traceoff_probe_ops = { + .func = ftrace_traceoff, + .print = ftrace_traceoff_print, +}; + +static struct ftrace_probe_ops stacktrace_probe_ops = { + .func = ftrace_stacktrace, + .print = ftrace_stacktrace_print, +}; + static int -ftrace_trace_onoff_callback(struct ftrace_hash *hash, - char *glob, char *cmd, char *param, int enable) +ftrace_trace_probe_callback(struct ftrace_probe_ops *ops, + struct ftrace_hash *hash, char *glob, + char *cmd, char *param, int enable) { - struct ftrace_probe_ops *ops; void *count = (void *)-1; char *number; int ret; @@ -345,14 +370,10 @@ ftrace_trace_onoff_callback(struct ftrace_hash *hash, if (!enable) return -EINVAL; - if (glob[0] == '!') - return ftrace_trace_onoff_unreg(glob+1, cmd, param); - - /* we register both traceon and traceoff to this callback */ - if (strcmp(cmd, "traceon") == 0) - ops = &traceon_probe_ops; - else - ops = &traceoff_probe_ops; + if (glob[0] == '!') { + unregister_ftrace_function_probe_func(glob+1, ops); + return 0; + } if (!param) goto out_reg; @@ -376,6 +397,34 @@ ftrace_trace_onoff_callback(struct ftrace_hash *hash, return ret < 0 ? ret : 0; } +static int +ftrace_trace_onoff_callback(struct ftrace_hash *hash, + char *glob, char *cmd, char *param, int enable) +{ + struct ftrace_probe_ops *ops; + + /* we register both traceon and traceoff to this callback */ + if (strcmp(cmd, "traceon") == 0) + ops = param ? &traceon_count_probe_ops : &traceon_probe_ops; + else + ops = param ? &traceoff_count_probe_ops : &traceoff_probe_ops; + + return ftrace_trace_probe_callback(ops, hash, glob, cmd, + param, enable); +} + +static int +ftrace_stacktrace_callback(struct ftrace_hash *hash, + char *glob, char *cmd, char *param, int enable) +{ + struct ftrace_probe_ops *ops; + + ops = param ? &stacktrace_count_probe_ops : &stacktrace_probe_ops; + + return ftrace_trace_probe_callback(ops, hash, glob, cmd, + param, enable); +} + static struct ftrace_func_command ftrace_traceon_cmd = { .name = "traceon", .func = ftrace_trace_onoff_callback, @@ -386,6 +435,11 @@ static struct ftrace_func_command ftrace_traceoff_cmd = { .func = ftrace_trace_onoff_callback, }; +static struct ftrace_func_command ftrace_stacktrace_cmd = { + .name = "stacktrace", + .func = ftrace_stacktrace_callback, +}; + static int __init init_func_cmd_traceon(void) { int ret; @@ -397,6 +451,12 @@ static int __init init_func_cmd_traceon(void) ret = register_ftrace_command(&ftrace_traceon_cmd); if (ret) unregister_ftrace_command(&ftrace_traceoff_cmd); + + ret = register_ftrace_command(&ftrace_stacktrace_cmd); + if (ret) { + unregister_ftrace_command(&ftrace_traceoff_cmd); + unregister_ftrace_command(&ftrace_traceon_cmd); + } return ret; } #else diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 4edb4b74eb7e..8388bc99f2ee 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -47,6 +47,8 @@ struct fgraph_data { #define TRACE_GRAPH_PRINT_ABS_TIME 0x20 #define TRACE_GRAPH_PRINT_IRQS 0x40 +static unsigned int max_depth; + static struct tracer_opt trace_opts[] = { /* Display overruns? (for self-debug purpose) */ { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) }, @@ -189,10 +191,16 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer) ftrace_pop_return_trace(&trace, &ret, frame_pointer); trace.rettime = trace_clock_local(); - ftrace_graph_return(&trace); barrier(); current->curr_ret_stack--; + /* + * The trace should run after decrementing the ret counter + * in case an interrupt were to come in. We don't want to + * lose the interrupt if max_depth is set. + */ + ftrace_graph_return(&trace); + if (unlikely(!ret)) { ftrace_graph_stop(); WARN_ON(1); @@ -210,7 +218,7 @@ int __trace_graph_entry(struct trace_array *tr, { struct ftrace_event_call *call = &event_funcgraph_entry; struct ring_buffer_event *event; - struct ring_buffer *buffer = tr->buffer; + struct ring_buffer *buffer = tr->trace_buffer.buffer; struct ftrace_graph_ent_entry *entry; if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) @@ -250,13 +258,14 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) return 0; /* trace it when it is-nested-in or is a function enabled. */ - if (!(trace->depth || ftrace_graph_addr(trace->func)) || - ftrace_graph_ignore_irqs()) + if ((!(trace->depth || ftrace_graph_addr(trace->func)) || + ftrace_graph_ignore_irqs()) || + (max_depth && trace->depth >= max_depth)) return 0; local_irq_save(flags); cpu = raw_smp_processor_id(); - data = tr->data[cpu]; + data = per_cpu_ptr(tr->trace_buffer.data, cpu); disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) { pc = preempt_count(); @@ -314,7 +323,7 @@ void __trace_graph_return(struct trace_array *tr, { struct ftrace_event_call *call = &event_funcgraph_exit; struct ring_buffer_event *event; - struct ring_buffer *buffer = tr->buffer; + struct ring_buffer *buffer = tr->trace_buffer.buffer; struct ftrace_graph_ret_entry *entry; if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) @@ -341,7 +350,7 @@ void trace_graph_return(struct ftrace_graph_ret *trace) local_irq_save(flags); cpu = raw_smp_processor_id(); - data = tr->data[cpu]; + data = per_cpu_ptr(tr->trace_buffer.data, cpu); disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) { pc = preempt_count(); @@ -551,9 +560,9 @@ get_return_for_leaf(struct trace_iterator *iter, * We need to consume the current entry to see * the next one. */ - ring_buffer_consume(iter->tr->buffer, iter->cpu, + ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu, NULL, NULL); - event = ring_buffer_peek(iter->tr->buffer, iter->cpu, + event = ring_buffer_peek(iter->trace_buffer->buffer, iter->cpu, NULL, NULL); } @@ -1457,6 +1466,59 @@ static struct tracer graph_trace __read_mostly = { #endif }; + +static ssize_t +graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt, + loff_t *ppos) +{ + unsigned long val; + int ret; + + ret = kstrtoul_from_user(ubuf, cnt, 10, &val); + if (ret) + return ret; + + max_depth = val; + + *ppos += cnt; + + return cnt; +} + +static ssize_t +graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt, + loff_t *ppos) +{ + char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/ + int n; + + n = sprintf(buf, "%d\n", max_depth); + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, n); +} + +static const struct file_operations graph_depth_fops = { + .open = tracing_open_generic, + .write = graph_depth_write, + .read = graph_depth_read, + .llseek = generic_file_llseek, +}; + +static __init int init_graph_debugfs(void) +{ + struct dentry *d_tracer; + + d_tracer = tracing_init_dentry(); + if (!d_tracer) + return 0; + + trace_create_file("max_graph_depth", 0644, d_tracer, + NULL, &graph_depth_fops); + + return 0; +} +fs_initcall(init_graph_debugfs); + static __init int init_graph_trace(void) { max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1); diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 713a2cac4881..b19d065a28cb 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -32,7 +32,8 @@ enum { static int trace_type __read_mostly; -static int save_lat_flag; +static int save_flags; +static bool function_enabled; static void stop_irqsoff_tracer(struct trace_array *tr, int graph); static int start_irqsoff_tracer(struct trace_array *tr, int graph); @@ -121,7 +122,7 @@ static int func_prolog_dec(struct trace_array *tr, if (!irqs_disabled_flags(*flags)) return 0; - *data = tr->data[cpu]; + *data = per_cpu_ptr(tr->trace_buffer.data, cpu); disabled = atomic_inc_return(&(*data)->disabled); if (likely(disabled == 1)) @@ -175,7 +176,7 @@ static int irqsoff_set_flag(u32 old_flags, u32 bit, int set) per_cpu(tracing_cpu, cpu) = 0; tracing_max_latency = 0; - tracing_reset_online_cpus(irqsoff_trace); + tracing_reset_online_cpus(&irqsoff_trace->trace_buffer); return start_irqsoff_tracer(irqsoff_trace, set); } @@ -380,7 +381,7 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip) if (per_cpu(tracing_cpu, cpu)) return; - data = tr->data[cpu]; + data = per_cpu_ptr(tr->trace_buffer.data, cpu); if (unlikely(!data) || atomic_read(&data->disabled)) return; @@ -418,7 +419,7 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip) if (!tracer_enabled) return; - data = tr->data[cpu]; + data = per_cpu_ptr(tr->trace_buffer.data, cpu); if (unlikely(!data) || !data->critical_start || atomic_read(&data->disabled)) @@ -528,15 +529,60 @@ void trace_preempt_off(unsigned long a0, unsigned long a1) } #endif /* CONFIG_PREEMPT_TRACER */ -static int start_irqsoff_tracer(struct trace_array *tr, int graph) +static int register_irqsoff_function(int graph, int set) { - int ret = 0; + int ret; - if (!graph) - ret = register_ftrace_function(&trace_ops); - else + /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ + if (function_enabled || (!set && !(trace_flags & TRACE_ITER_FUNCTION))) + return 0; + + if (graph) ret = register_ftrace_graph(&irqsoff_graph_return, &irqsoff_graph_entry); + else + ret = register_ftrace_function(&trace_ops); + + if (!ret) + function_enabled = true; + + return ret; +} + +static void unregister_irqsoff_function(int graph) +{ + if (!function_enabled) + return; + + if (graph) + unregister_ftrace_graph(); + else + unregister_ftrace_function(&trace_ops); + + function_enabled = false; +} + +static void irqsoff_function_set(int set) +{ + if (set) + register_irqsoff_function(is_graph(), 1); + else + unregister_irqsoff_function(is_graph()); +} + +static int irqsoff_flag_changed(struct tracer *tracer, u32 mask, int set) +{ + if (mask & TRACE_ITER_FUNCTION) + irqsoff_function_set(set); + + return trace_keep_overwrite(tracer, mask, set); +} + +static int start_irqsoff_tracer(struct trace_array *tr, int graph) +{ + int ret; + + ret = register_irqsoff_function(graph, 0); if (!ret && tracing_is_enabled()) tracer_enabled = 1; @@ -550,22 +596,22 @@ static void stop_irqsoff_tracer(struct trace_array *tr, int graph) { tracer_enabled = 0; - if (!graph) - unregister_ftrace_function(&trace_ops); - else - unregister_ftrace_graph(); + unregister_irqsoff_function(graph); } static void __irqsoff_tracer_init(struct trace_array *tr) { - save_lat_flag = trace_flags & TRACE_ITER_LATENCY_FMT; - trace_flags |= TRACE_ITER_LATENCY_FMT; + save_flags = trace_flags; + + /* non overwrite screws up the latency tracers */ + set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); + set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); tracing_max_latency = 0; irqsoff_trace = tr; /* make sure that the tracer is visible */ smp_wmb(); - tracing_reset_online_cpus(tr); + tracing_reset_online_cpus(&tr->trace_buffer); if (start_irqsoff_tracer(tr, is_graph())) printk(KERN_ERR "failed to start irqsoff tracer\n"); @@ -573,10 +619,13 @@ static void __irqsoff_tracer_init(struct trace_array *tr) static void irqsoff_tracer_reset(struct trace_array *tr) { + int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; + int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; + stop_irqsoff_tracer(tr, is_graph()); - if (!save_lat_flag) - trace_flags &= ~TRACE_ITER_LATENCY_FMT; + set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); + set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); } static void irqsoff_tracer_start(struct trace_array *tr) @@ -609,6 +658,7 @@ static struct tracer irqsoff_tracer __read_mostly = .print_line = irqsoff_print_line, .flags = &tracer_flags, .set_flag = irqsoff_set_flag, + .flag_changed = irqsoff_flag_changed, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_irqsoff, #endif @@ -642,6 +692,7 @@ static struct tracer preemptoff_tracer __read_mostly = .print_line = irqsoff_print_line, .flags = &tracer_flags, .set_flag = irqsoff_set_flag, + .flag_changed = irqsoff_flag_changed, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_preemptoff, #endif @@ -677,6 +728,7 @@ static struct tracer preemptirqsoff_tracer __read_mostly = .print_line = irqsoff_print_line, .flags = &tracer_flags, .set_flag = irqsoff_set_flag, + .flag_changed = irqsoff_flag_changed, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_preemptirqsoff, #endif diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c index 3c5c5dfea0b3..bd90e1b06088 100644 --- a/kernel/trace/trace_kdb.c +++ b/kernel/trace/trace_kdb.c @@ -26,7 +26,7 @@ static void ftrace_dump_buf(int skip_lines, long cpu_file) trace_init_global_iter(&iter); for_each_tracing_cpu(cpu) { - atomic_inc(&iter.tr->data[cpu]->disabled); + atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); } old_userobj = trace_flags; @@ -43,17 +43,17 @@ static void ftrace_dump_buf(int skip_lines, long cpu_file) iter.iter_flags |= TRACE_FILE_LAT_FMT; iter.pos = -1; - if (cpu_file == TRACE_PIPE_ALL_CPU) { + if (cpu_file == RING_BUFFER_ALL_CPUS) { for_each_tracing_cpu(cpu) { iter.buffer_iter[cpu] = - ring_buffer_read_prepare(iter.tr->buffer, cpu); + ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu); ring_buffer_read_start(iter.buffer_iter[cpu]); tracing_iter_reset(&iter, cpu); } } else { iter.cpu_file = cpu_file; iter.buffer_iter[cpu_file] = - ring_buffer_read_prepare(iter.tr->buffer, cpu_file); + ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu_file); ring_buffer_read_start(iter.buffer_iter[cpu_file]); tracing_iter_reset(&iter, cpu_file); } @@ -83,7 +83,7 @@ out: trace_flags = old_userobj; for_each_tracing_cpu(cpu) { - atomic_dec(&iter.tr->data[cpu]->disabled); + atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); } for_each_tracing_cpu(cpu) @@ -115,7 +115,7 @@ static int kdb_ftdump(int argc, const char **argv) !cpu_online(cpu_file)) return KDB_BADINT; } else { - cpu_file = TRACE_PIPE_ALL_CPU; + cpu_file = RING_BUFFER_ALL_CPUS; } kdb_trap_printk++; diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index fd3c8aae55e5..a5e8f4878bfa 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -31,7 +31,7 @@ static void mmio_reset_data(struct trace_array *tr) overrun_detected = false; prev_overruns = 0; - tracing_reset_online_cpus(tr); + tracing_reset_online_cpus(&tr->trace_buffer); } static int mmio_trace_init(struct trace_array *tr) @@ -128,7 +128,7 @@ static void mmio_close(struct trace_iterator *iter) static unsigned long count_overruns(struct trace_iterator *iter) { unsigned long cnt = atomic_xchg(&dropped_count, 0); - unsigned long over = ring_buffer_overruns(iter->tr->buffer); + unsigned long over = ring_buffer_overruns(iter->trace_buffer->buffer); if (over > prev_overruns) cnt += over - prev_overruns; @@ -309,7 +309,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr, struct mmiotrace_rw *rw) { struct ftrace_event_call *call = &event_mmiotrace_rw; - struct ring_buffer *buffer = tr->buffer; + struct ring_buffer *buffer = tr->trace_buffer.buffer; struct ring_buffer_event *event; struct trace_mmiotrace_rw *entry; int pc = preempt_count(); @@ -330,7 +330,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr, void mmio_trace_rw(struct mmiotrace_rw *rw) { struct trace_array *tr = mmio_trace_array; - struct trace_array_cpu *data = tr->data[smp_processor_id()]; + struct trace_array_cpu *data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id()); __trace_mmiotrace_rw(tr, data, rw); } @@ -339,7 +339,7 @@ static void __trace_mmiotrace_map(struct trace_array *tr, struct mmiotrace_map *map) { struct ftrace_event_call *call = &event_mmiotrace_map; - struct ring_buffer *buffer = tr->buffer; + struct ring_buffer *buffer = tr->trace_buffer.buffer; struct ring_buffer_event *event; struct trace_mmiotrace_map *entry; int pc = preempt_count(); @@ -363,7 +363,7 @@ void mmio_trace_mapping(struct mmiotrace_map *map) struct trace_array_cpu *data; preempt_disable(); - data = tr->data[smp_processor_id()]; + data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id()); __trace_mmiotrace_map(tr, data, map); preempt_enable(); } diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 194d79602dc7..bb922d9ee51b 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -14,7 +14,7 @@ /* must be a power of 2 */ #define EVENT_HASHSIZE 128 -DECLARE_RWSEM(trace_event_mutex); +DECLARE_RWSEM(trace_event_sem); static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly; @@ -37,6 +37,22 @@ int trace_print_seq(struct seq_file *m, struct trace_seq *s) return ret; } +enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + struct trace_entry *entry = iter->ent; + struct bputs_entry *field; + int ret; + + trace_assign_type(field, entry); + + ret = trace_seq_puts(s, field->str); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + return TRACE_TYPE_HANDLED; +} + enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; @@ -397,6 +413,32 @@ ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len) } EXPORT_SYMBOL(ftrace_print_hex_seq); +int ftrace_raw_output_prep(struct trace_iterator *iter, + struct trace_event *trace_event) +{ + struct ftrace_event_call *event; + struct trace_seq *s = &iter->seq; + struct trace_seq *p = &iter->tmp_seq; + struct trace_entry *entry; + int ret; + + event = container_of(trace_event, struct ftrace_event_call, event); + entry = iter->ent; + + if (entry->type != event->event.type) { + WARN_ON_ONCE(1); + return TRACE_TYPE_UNHANDLED; + } + + trace_seq_init(p); + ret = trace_seq_printf(s, "%s: ", event->name); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + return 0; +} +EXPORT_SYMBOL(ftrace_raw_output_prep); + #ifdef CONFIG_KRETPROBES static inline const char *kretprobed(const char *name) { @@ -617,7 +659,7 @@ lat_print_timestamp(struct trace_iterator *iter, u64 next_ts) { unsigned long verbose = trace_flags & TRACE_ITER_VERBOSE; unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS; - unsigned long long abs_ts = iter->ts - iter->tr->time_start; + unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start; unsigned long long rel_ts = next_ts - iter->ts; struct trace_seq *s = &iter->seq; @@ -739,12 +781,11 @@ static int task_state_char(unsigned long state) struct trace_event *ftrace_find_event(int type) { struct trace_event *event; - struct hlist_node *n; unsigned key; key = type & (EVENT_HASHSIZE - 1); - hlist_for_each_entry(event, n, &event_hash[key], node) { + hlist_for_each_entry(event, &event_hash[key], node) { if (event->type == type) return event; } @@ -784,12 +825,12 @@ static int trace_search_list(struct list_head **list) void trace_event_read_lock(void) { - down_read(&trace_event_mutex); + down_read(&trace_event_sem); } void trace_event_read_unlock(void) { - up_read(&trace_event_mutex); + up_read(&trace_event_sem); } /** @@ -812,7 +853,7 @@ int register_ftrace_event(struct trace_event *event) unsigned key; int ret = 0; - down_write(&trace_event_mutex); + down_write(&trace_event_sem); if (WARN_ON(!event)) goto out; @@ -867,14 +908,14 @@ int register_ftrace_event(struct trace_event *event) ret = event->type; out: - up_write(&trace_event_mutex); + up_write(&trace_event_sem); return ret; } EXPORT_SYMBOL_GPL(register_ftrace_event); /* - * Used by module code with the trace_event_mutex held for write. + * Used by module code with the trace_event_sem held for write. */ int __unregister_ftrace_event(struct trace_event *event) { @@ -889,9 +930,9 @@ int __unregister_ftrace_event(struct trace_event *event) */ int unregister_ftrace_event(struct trace_event *event) { - down_write(&trace_event_mutex); + down_write(&trace_event_sem); __unregister_ftrace_event(event); - up_write(&trace_event_mutex); + up_write(&trace_event_sem); return 0; } @@ -1218,6 +1259,64 @@ static struct trace_event trace_user_stack_event = { .funcs = &trace_user_stack_funcs, }; +/* TRACE_BPUTS */ +static enum print_line_t +trace_bputs_print(struct trace_iterator *iter, int flags, + struct trace_event *event) +{ + struct trace_entry *entry = iter->ent; + struct trace_seq *s = &iter->seq; + struct bputs_entry *field; + + trace_assign_type(field, entry); + + if (!seq_print_ip_sym(s, field->ip, flags)) + goto partial; + + if (!trace_seq_puts(s, ": ")) + goto partial; + + if (!trace_seq_puts(s, field->str)) + goto partial; + + return TRACE_TYPE_HANDLED; + + partial: + return TRACE_TYPE_PARTIAL_LINE; +} + + +static enum print_line_t +trace_bputs_raw(struct trace_iterator *iter, int flags, + struct trace_event *event) +{ + struct bputs_entry *field; + struct trace_seq *s = &iter->seq; + + trace_assign_type(field, iter->ent); + + if (!trace_seq_printf(s, ": %lx : ", field->ip)) + goto partial; + + if (!trace_seq_puts(s, field->str)) + goto partial; + + return TRACE_TYPE_HANDLED; + + partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +static struct trace_event_functions trace_bputs_funcs = { + .trace = trace_bputs_print, + .raw = trace_bputs_raw, +}; + +static struct trace_event trace_bputs_event = { + .type = TRACE_BPUTS, + .funcs = &trace_bputs_funcs, +}; + /* TRACE_BPRINT */ static enum print_line_t trace_bprint_print(struct trace_iterator *iter, int flags, @@ -1330,6 +1429,7 @@ static struct trace_event *events[] __initdata = { &trace_wake_event, &trace_stack_event, &trace_user_stack_event, + &trace_bputs_event, &trace_bprint_event, &trace_print_event, NULL diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h index c038eba0492b..127a9d8c8357 100644 --- a/kernel/trace/trace_output.h +++ b/kernel/trace/trace_output.h @@ -5,6 +5,8 @@ #include "trace.h" extern enum print_line_t +trace_print_bputs_msg_only(struct trace_iterator *iter); +extern enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter); extern enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter); @@ -31,7 +33,7 @@ trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry); /* used by module unregistering */ extern int __unregister_ftrace_event(struct trace_event *event); -extern struct rw_semaphore trace_event_mutex; +extern struct rw_semaphore trace_event_sem; #define MAX_MEMHEX_BYTES 8 #define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1) diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 933708677814..5c7e09d10d74 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -66,7 +66,6 @@ #define TP_FLAG_TRACE 1 #define TP_FLAG_PROFILE 2 #define TP_FLAG_REGISTERED 4 -#define TP_FLAG_UPROBE 8 /* data_rloc: data relative location, compatible with u32 */ diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 3374c792ccd8..4e98e3b257a3 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -28,7 +28,7 @@ tracing_sched_switch_trace(struct trace_array *tr, unsigned long flags, int pc) { struct ftrace_event_call *call = &event_context_switch; - struct ring_buffer *buffer = tr->buffer; + struct ring_buffer *buffer = tr->trace_buffer.buffer; struct ring_buffer_event *event; struct ctx_switch_entry *entry; @@ -69,7 +69,7 @@ probe_sched_switch(void *ignore, struct task_struct *prev, struct task_struct *n pc = preempt_count(); local_irq_save(flags); cpu = raw_smp_processor_id(); - data = ctx_trace->data[cpu]; + data = per_cpu_ptr(ctx_trace->trace_buffer.data, cpu); if (likely(!atomic_read(&data->disabled))) tracing_sched_switch_trace(ctx_trace, prev, next, flags, pc); @@ -86,7 +86,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr, struct ftrace_event_call *call = &event_wakeup; struct ring_buffer_event *event; struct ctx_switch_entry *entry; - struct ring_buffer *buffer = tr->buffer; + struct ring_buffer *buffer = tr->trace_buffer.buffer; event = trace_buffer_lock_reserve(buffer, TRACE_WAKE, sizeof(*entry), flags, pc); @@ -123,7 +123,7 @@ probe_sched_wakeup(void *ignore, struct task_struct *wakee, int success) pc = preempt_count(); local_irq_save(flags); cpu = raw_smp_processor_id(); - data = ctx_trace->data[cpu]; + data = per_cpu_ptr(ctx_trace->trace_buffer.data, cpu); if (likely(!atomic_read(&data->disabled))) tracing_sched_wakeup_trace(ctx_trace, wakee, current, diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 9fe45fcefca0..fee77e15d815 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -15,8 +15,8 @@ #include <linux/kallsyms.h> #include <linux/uaccess.h> #include <linux/ftrace.h> +#include <linux/sched/rt.h> #include <trace/events/sched.h> - #include "trace.h" static struct trace_array *wakeup_trace; @@ -36,7 +36,8 @@ static void __wakeup_reset(struct trace_array *tr); static int wakeup_graph_entry(struct ftrace_graph_ent *trace); static void wakeup_graph_return(struct ftrace_graph_ret *trace); -static int save_lat_flag; +static int save_flags; +static bool function_enabled; #define TRACE_DISPLAY_GRAPH 1 @@ -89,7 +90,7 @@ func_prolog_preempt_disable(struct trace_array *tr, if (cpu != wakeup_current_cpu) goto out_enable; - *data = tr->data[cpu]; + *data = per_cpu_ptr(tr->trace_buffer.data, cpu); disabled = atomic_inc_return(&(*data)->disabled); if (unlikely(disabled != 1)) goto out; @@ -134,15 +135,60 @@ static struct ftrace_ops trace_ops __read_mostly = }; #endif /* CONFIG_FUNCTION_TRACER */ -static int start_func_tracer(int graph) +static int register_wakeup_function(int graph, int set) { int ret; - if (!graph) - ret = register_ftrace_function(&trace_ops); - else + /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ + if (function_enabled || (!set && !(trace_flags & TRACE_ITER_FUNCTION))) + return 0; + + if (graph) ret = register_ftrace_graph(&wakeup_graph_return, &wakeup_graph_entry); + else + ret = register_ftrace_function(&trace_ops); + + if (!ret) + function_enabled = true; + + return ret; +} + +static void unregister_wakeup_function(int graph) +{ + if (!function_enabled) + return; + + if (graph) + unregister_ftrace_graph(); + else + unregister_ftrace_function(&trace_ops); + + function_enabled = false; +} + +static void wakeup_function_set(int set) +{ + if (set) + register_wakeup_function(is_graph(), 1); + else + unregister_wakeup_function(is_graph()); +} + +static int wakeup_flag_changed(struct tracer *tracer, u32 mask, int set) +{ + if (mask & TRACE_ITER_FUNCTION) + wakeup_function_set(set); + + return trace_keep_overwrite(tracer, mask, set); +} + +static int start_func_tracer(int graph) +{ + int ret; + + ret = register_wakeup_function(graph, 0); if (!ret && tracing_is_enabled()) tracer_enabled = 1; @@ -156,10 +202,7 @@ static void stop_func_tracer(int graph) { tracer_enabled = 0; - if (!graph) - unregister_ftrace_function(&trace_ops); - else - unregister_ftrace_graph(); + unregister_wakeup_function(graph); } #ifdef CONFIG_FUNCTION_GRAPH_TRACER @@ -353,7 +396,7 @@ probe_wakeup_sched_switch(void *ignore, /* disable local data, not wakeup_cpu data */ cpu = raw_smp_processor_id(); - disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled); + disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); if (likely(disabled != 1)) goto out; @@ -365,7 +408,7 @@ probe_wakeup_sched_switch(void *ignore, goto out_unlock; /* The task we are waiting for is waking up */ - data = wakeup_trace->data[wakeup_cpu]; + data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc); tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc); @@ -387,7 +430,7 @@ out_unlock: arch_spin_unlock(&wakeup_lock); local_irq_restore(flags); out: - atomic_dec(&wakeup_trace->data[cpu]->disabled); + atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); } static void __wakeup_reset(struct trace_array *tr) @@ -405,7 +448,7 @@ static void wakeup_reset(struct trace_array *tr) { unsigned long flags; - tracing_reset_online_cpus(tr); + tracing_reset_online_cpus(&tr->trace_buffer); local_irq_save(flags); arch_spin_lock(&wakeup_lock); @@ -435,7 +478,7 @@ probe_wakeup(void *ignore, struct task_struct *p, int success) return; pc = preempt_count(); - disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled); + disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); if (unlikely(disabled != 1)) goto out; @@ -458,7 +501,7 @@ probe_wakeup(void *ignore, struct task_struct *p, int success) local_save_flags(flags); - data = wakeup_trace->data[wakeup_cpu]; + data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); data->preempt_timestamp = ftrace_now(cpu); tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc); @@ -472,7 +515,7 @@ probe_wakeup(void *ignore, struct task_struct *p, int success) out_locked: arch_spin_unlock(&wakeup_lock); out: - atomic_dec(&wakeup_trace->data[cpu]->disabled); + atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); } static void start_wakeup_tracer(struct trace_array *tr) @@ -540,8 +583,11 @@ static void stop_wakeup_tracer(struct trace_array *tr) static int __wakeup_tracer_init(struct trace_array *tr) { - save_lat_flag = trace_flags & TRACE_ITER_LATENCY_FMT; - trace_flags |= TRACE_ITER_LATENCY_FMT; + save_flags = trace_flags; + + /* non overwrite screws up the latency tracers */ + set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); + set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); tracing_max_latency = 0; wakeup_trace = tr; @@ -563,12 +609,15 @@ static int wakeup_rt_tracer_init(struct trace_array *tr) static void wakeup_tracer_reset(struct trace_array *tr) { + int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; + int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; + stop_wakeup_tracer(tr); /* make sure we put back any tasks we are tracing */ wakeup_reset(tr); - if (!save_lat_flag) - trace_flags &= ~TRACE_ITER_LATENCY_FMT; + set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); + set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); } static void wakeup_tracer_start(struct trace_array *tr) @@ -594,6 +643,7 @@ static struct tracer wakeup_tracer __read_mostly = .print_line = wakeup_print_line, .flags = &tracer_flags, .set_flag = wakeup_set_flag, + .flag_changed = wakeup_flag_changed, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_wakeup, #endif @@ -615,6 +665,7 @@ static struct tracer wakeup_rt_tracer __read_mostly = .print_line = wakeup_print_line, .flags = &tracer_flags, .set_flag = wakeup_set_flag, + .flag_changed = wakeup_flag_changed, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_wakeup, #endif diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 47623169a815..55e2cf66967b 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -21,13 +21,13 @@ static inline int trace_valid_entry(struct trace_entry *entry) return 0; } -static int trace_test_buffer_cpu(struct trace_array *tr, int cpu) +static int trace_test_buffer_cpu(struct trace_buffer *buf, int cpu) { struct ring_buffer_event *event; struct trace_entry *entry; unsigned int loops = 0; - while ((event = ring_buffer_consume(tr->buffer, cpu, NULL, NULL))) { + while ((event = ring_buffer_consume(buf->buffer, cpu, NULL, NULL))) { entry = ring_buffer_event_data(event); /* @@ -58,7 +58,7 @@ static int trace_test_buffer_cpu(struct trace_array *tr, int cpu) * Test the trace buffer to see if all the elements * are still sane. */ -static int trace_test_buffer(struct trace_array *tr, unsigned long *count) +static int trace_test_buffer(struct trace_buffer *buf, unsigned long *count) { unsigned long flags, cnt = 0; int cpu, ret = 0; @@ -67,7 +67,7 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) local_irq_save(flags); arch_spin_lock(&ftrace_max_lock); - cnt = ring_buffer_entries(tr->buffer); + cnt = ring_buffer_entries(buf->buffer); /* * The trace_test_buffer_cpu runs a while loop to consume all data. @@ -78,7 +78,7 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) */ tracing_off(); for_each_possible_cpu(cpu) { - ret = trace_test_buffer_cpu(tr, cpu); + ret = trace_test_buffer_cpu(buf, cpu); if (ret) break; } @@ -355,7 +355,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, msleep(100); /* we should have nothing in the buffer */ - ret = trace_test_buffer(tr, &count); + ret = trace_test_buffer(&tr->trace_buffer, &count); if (ret) goto out; @@ -376,7 +376,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, ftrace_enabled = 0; /* check the trace buffer */ - ret = trace_test_buffer(tr, &count); + ret = trace_test_buffer(&tr->trace_buffer, &count); tracing_start(); /* we should only have one item */ @@ -415,7 +415,8 @@ static void trace_selftest_test_recursion_func(unsigned long ip, * The ftrace infrastructure should provide the recursion * protection. If not, this will crash the kernel! */ - trace_selftest_recursion_cnt++; + if (trace_selftest_recursion_cnt++ > 10) + return; DYN_FTRACE_TEST_NAME(); } @@ -452,7 +453,6 @@ trace_selftest_function_recursion(void) char *func_name; int len; int ret; - int cnt; /* The previous test PASSED */ pr_cont("PASSED\n"); @@ -510,19 +510,10 @@ trace_selftest_function_recursion(void) unregister_ftrace_function(&test_recsafe_probe); - /* - * If arch supports all ftrace features, and no other task - * was on the list, we should be fine. - */ - if (!ftrace_nr_registered_ops() && !FTRACE_FORCE_LIST_FUNC) - cnt = 2; /* Should have recursed */ - else - cnt = 1; - ret = -1; - if (trace_selftest_recursion_cnt != cnt) { - pr_cont("*callback not called expected %d times (%d)* ", - cnt, trace_selftest_recursion_cnt); + if (trace_selftest_recursion_cnt != 2) { + pr_cont("*callback not called expected 2 times (%d)* ", + trace_selftest_recursion_cnt); goto out; } @@ -568,7 +559,7 @@ trace_selftest_function_regs(void) int ret; int supported = 0; -#ifdef ARCH_SUPPORTS_FTRACE_SAVE_REGS +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS supported = 1; #endif @@ -675,7 +666,7 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) ftrace_enabled = 0; /* check the trace buffer */ - ret = trace_test_buffer(tr, &count); + ret = trace_test_buffer(&tr->trace_buffer, &count); trace->reset(tr); tracing_start(); @@ -712,8 +703,6 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) /* Maximum number of functions to trace before diagnosing a hang */ #define GRAPH_MAX_FUNC_TEST 100000000 -static void -__ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode); static unsigned int graph_hang_thresh; /* Wrap the real function entry probe to avoid possible hanging */ @@ -723,8 +712,11 @@ static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace) if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) { ftrace_graph_stop(); printk(KERN_WARNING "BUG: Function graph tracer hang!\n"); - if (ftrace_dump_on_oops) - __ftrace_dump(false, DUMP_ALL); + if (ftrace_dump_on_oops) { + ftrace_dump(DUMP_ALL); + /* ftrace_dump() disables tracing */ + tracing_on(); + } return 0; } @@ -746,7 +738,7 @@ trace_selftest_startup_function_graph(struct tracer *trace, * Simulate the init() callback but we attach a watchdog callback * to detect and recover from possible hangs */ - tracing_reset_online_cpus(tr); + tracing_reset_online_cpus(&tr->trace_buffer); set_graph_array(tr); ret = register_ftrace_graph(&trace_graph_return, &trace_graph_entry_watchdog); @@ -769,7 +761,7 @@ trace_selftest_startup_function_graph(struct tracer *trace, tracing_stop(); /* check the trace buffer */ - ret = trace_test_buffer(tr, &count); + ret = trace_test_buffer(&tr->trace_buffer, &count); trace->reset(tr); tracing_start(); @@ -824,9 +816,9 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr) /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ - ret = trace_test_buffer(tr, NULL); + ret = trace_test_buffer(&tr->trace_buffer, NULL); if (!ret) - ret = trace_test_buffer(&max_tr, &count); + ret = trace_test_buffer(&tr->max_buffer, &count); trace->reset(tr); tracing_start(); @@ -886,9 +878,9 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr) /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ - ret = trace_test_buffer(tr, NULL); + ret = trace_test_buffer(&tr->trace_buffer, NULL); if (!ret) - ret = trace_test_buffer(&max_tr, &count); + ret = trace_test_buffer(&tr->max_buffer, &count); trace->reset(tr); tracing_start(); @@ -952,11 +944,11 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ - ret = trace_test_buffer(tr, NULL); + ret = trace_test_buffer(&tr->trace_buffer, NULL); if (ret) goto out; - ret = trace_test_buffer(&max_tr, &count); + ret = trace_test_buffer(&tr->max_buffer, &count); if (ret) goto out; @@ -982,11 +974,11 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ - ret = trace_test_buffer(tr, NULL); + ret = trace_test_buffer(&tr->trace_buffer, NULL); if (ret) goto out; - ret = trace_test_buffer(&max_tr, &count); + ret = trace_test_buffer(&tr->max_buffer, &count); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); @@ -1093,10 +1085,10 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ - ret = trace_test_buffer(tr, NULL); + ret = trace_test_buffer(&tr->trace_buffer, NULL); printk("ret = %d\n", ret); if (!ret) - ret = trace_test_buffer(&max_tr, &count); + ret = trace_test_buffer(&tr->max_buffer, &count); trace->reset(tr); @@ -1135,7 +1127,7 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr /* stop the tracing. */ tracing_stop(); /* check the trace buffer */ - ret = trace_test_buffer(tr, &count); + ret = trace_test_buffer(&tr->trace_buffer, &count); trace->reset(tr); tracing_start(); diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 42ca822fc701..b20428c5efe2 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -20,13 +20,24 @@ #define STACK_TRACE_ENTRIES 500 +#ifdef CC_USING_FENTRY +# define fentry 1 +#else +# define fentry 0 +#endif + static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] = { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX }; static unsigned stack_dump_index[STACK_TRACE_ENTRIES]; +/* + * Reserve one entry for the passed in ip. This will allow + * us to remove most or all of the stack size overhead + * added by the stack tracer itself. + */ static struct stack_trace max_stack_trace = { - .max_entries = STACK_TRACE_ENTRIES, - .entries = stack_dump_trace, + .max_entries = STACK_TRACE_ENTRIES - 1, + .entries = &stack_dump_trace[1], }; static unsigned long max_stack_size; @@ -39,25 +50,34 @@ static DEFINE_MUTEX(stack_sysctl_mutex); int stack_tracer_enabled; static int last_stack_tracer_enabled; -static inline void check_stack(void) +static inline void +check_stack(unsigned long ip, unsigned long *stack) { unsigned long this_size, flags; unsigned long *p, *top, *start; + static int tracer_frame; + int frame_size = ACCESS_ONCE(tracer_frame); int i; - this_size = ((unsigned long)&this_size) & (THREAD_SIZE-1); + this_size = ((unsigned long)stack) & (THREAD_SIZE-1); this_size = THREAD_SIZE - this_size; + /* Remove the frame of the tracer */ + this_size -= frame_size; if (this_size <= max_stack_size) return; /* we do not handle interrupt stacks yet */ - if (!object_is_on_stack(&this_size)) + if (!object_is_on_stack(stack)) return; local_irq_save(flags); arch_spin_lock(&max_stack_lock); + /* In case another CPU set the tracer_frame on us */ + if (unlikely(!frame_size)) + this_size -= tracer_frame; + /* a race could have already updated it */ if (this_size <= max_stack_size) goto out; @@ -70,10 +90,18 @@ static inline void check_stack(void) save_stack_trace(&max_stack_trace); /* + * Add the passed in ip from the function tracer. + * Searching for this on the stack will skip over + * most of the overhead from the stack tracer itself. + */ + stack_dump_trace[0] = ip; + max_stack_trace.nr_entries++; + + /* * Now find where in the stack these are. */ i = 0; - start = &this_size; + start = stack; top = (unsigned long *) (((unsigned long)start & ~(THREAD_SIZE-1)) + THREAD_SIZE); @@ -97,6 +125,18 @@ static inline void check_stack(void) found = 1; /* Start the search from here */ start = p + 1; + /* + * We do not want to show the overhead + * of the stack tracer stack in the + * max stack. If we haven't figured + * out what that is, then figure it out + * now. + */ + if (unlikely(!tracer_frame) && i == 1) { + tracer_frame = (p - stack) * + sizeof(unsigned long); + max_stack_size -= tracer_frame; + } } } @@ -113,6 +153,7 @@ static void stack_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *pt_regs) { + unsigned long stack; int cpu; preempt_disable_notrace(); @@ -122,7 +163,26 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip, if (per_cpu(trace_active, cpu)++ != 0) goto out; - check_stack(); + /* + * When fentry is used, the traced function does not get + * its stack frame set up, and we lose the parent. + * The ip is pretty useless because the function tracer + * was called before that function set up its stack frame. + * In this case, we use the parent ip. + * + * By adding the return address of either the parent ip + * or the current ip we can disregard most of the stack usage + * caused by the stack tracer itself. + * + * The function tracer always reports the address of where the + * mcount call was, but the stack will hold the return address. + */ + if (fentry) + ip = parent_ip; + else + ip += MCOUNT_INSN_SIZE; + + check_stack(ip, &stack); out: per_cpu(trace_active, cpu)--; @@ -322,7 +382,7 @@ static const struct file_operations stack_trace_filter_fops = { .open = stack_trace_filter_open, .read = seq_read, .write = ftrace_filter_write, - .llseek = ftrace_regex_lseek, + .llseek = ftrace_filter_lseek, .release = ftrace_regex_release, }; @@ -371,6 +431,8 @@ static __init int stack_trace_init(void) struct dentry *d_tracer; d_tracer = tracing_init_dentry(); + if (!d_tracer) + return 0; trace_create_file("stack_max_size", 0644, d_tracer, &max_stack_size, &stack_max_size_fops); diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index 96cffb269e73..847f88a6194b 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -307,6 +307,8 @@ static int tracing_stat_init(void) struct dentry *d_tracing; d_tracing = tracing_init_dentry(); + if (!d_tracing) + return 0; stat_dir = debugfs_create_dir("trace_stat", d_tracing); if (!stat_dir) diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 7609dd6714c2..8f2ac73c7a5f 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -1,5 +1,6 @@ #include <trace/syscall.h> #include <trace/events/syscalls.h> +#include <linux/syscalls.h> #include <linux/slab.h> #include <linux/kernel.h> #include <linux/module.h> /* for MODULE_NAME_LEN via KSYM_SYMBOL_LEN */ @@ -11,10 +12,6 @@ #include "trace.h" static DEFINE_MUTEX(syscall_trace_lock); -static int sys_refcount_enter; -static int sys_refcount_exit; -static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls); -static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls); static int syscall_enter_register(struct ftrace_event_call *event, enum trace_reg type, void *data); @@ -40,13 +37,45 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name /* * Only compare after the "sys" prefix. Archs that use * syscall wrappers may have syscalls symbols aliases prefixed - * with "SyS" instead of "sys", leading to an unwanted + * with ".SyS" or ".sys" instead of "sys", leading to an unwanted * mismatch. */ return !strcmp(sym + 3, name + 3); } #endif +#ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS +/* + * Some architectures that allow for 32bit applications + * to run on a 64bit kernel, do not map the syscalls for + * the 32bit tasks the same as they do for 64bit tasks. + * + * *cough*x86*cough* + * + * In such a case, instead of reporting the wrong syscalls, + * simply ignore them. + * + * For an arch to ignore the compat syscalls it needs to + * define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS as well as + * define the function arch_trace_is_compat_syscall() to let + * the tracing system know that it should ignore it. + */ +static int +trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) +{ + if (unlikely(arch_trace_is_compat_syscall(regs))) + return -1; + + return syscall_get_nr(task, regs); +} +#else +static inline int +trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) +{ + return syscall_get_nr(task, regs); +} +#endif /* ARCH_TRACE_IGNORE_COMPAT_SYSCALLS */ + static __init struct syscall_metadata * find_syscall_meta(unsigned long syscall) { @@ -77,7 +106,7 @@ static struct syscall_metadata *syscall_nr_to_meta(int nr) return syscalls_metadata[nr]; } -enum print_line_t +static enum print_line_t print_syscall_enter(struct trace_iterator *iter, int flags, struct trace_event *event) { @@ -130,7 +159,7 @@ end: return TRACE_TYPE_HANDLED; } -enum print_line_t +static enum print_line_t print_syscall_exit(struct trace_iterator *iter, int flags, struct trace_event *event) { @@ -232,7 +261,7 @@ static void free_syscall_print_fmt(struct ftrace_event_call *call) kfree(call->print_fmt); } -static int syscall_enter_define_fields(struct ftrace_event_call *call) +static int __init syscall_enter_define_fields(struct ftrace_event_call *call) { struct syscall_trace_enter trace; struct syscall_metadata *meta = call->data; @@ -255,7 +284,7 @@ static int syscall_enter_define_fields(struct ftrace_event_call *call) return ret; } -static int syscall_exit_define_fields(struct ftrace_event_call *call) +static int __init syscall_exit_define_fields(struct ftrace_event_call *call) { struct syscall_trace_exit trace; int ret; @@ -270,19 +299,20 @@ static int syscall_exit_define_fields(struct ftrace_event_call *call) return ret; } -void ftrace_syscall_enter(void *ignore, struct pt_regs *regs, long id) +static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id) { + struct trace_array *tr = data; struct syscall_trace_enter *entry; struct syscall_metadata *sys_data; struct ring_buffer_event *event; struct ring_buffer *buffer; - int size; int syscall_nr; + int size; - syscall_nr = syscall_get_nr(current, regs); + syscall_nr = trace_get_syscall_nr(current, regs); if (syscall_nr < 0) return; - if (!test_bit(syscall_nr, enabled_enter_syscalls)) + if (!test_bit(syscall_nr, tr->enabled_enter_syscalls)) return; sys_data = syscall_nr_to_meta(syscall_nr); @@ -291,7 +321,8 @@ void ftrace_syscall_enter(void *ignore, struct pt_regs *regs, long id) size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; - event = trace_current_buffer_lock_reserve(&buffer, + buffer = tr->trace_buffer.buffer; + event = trace_buffer_lock_reserve(buffer, sys_data->enter_event->event.type, size, 0, 0); if (!event) return; @@ -305,25 +336,27 @@ void ftrace_syscall_enter(void *ignore, struct pt_regs *regs, long id) trace_current_buffer_unlock_commit(buffer, event, 0, 0); } -void ftrace_syscall_exit(void *ignore, struct pt_regs *regs, long ret) +static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret) { + struct trace_array *tr = data; struct syscall_trace_exit *entry; struct syscall_metadata *sys_data; struct ring_buffer_event *event; struct ring_buffer *buffer; int syscall_nr; - syscall_nr = syscall_get_nr(current, regs); + syscall_nr = trace_get_syscall_nr(current, regs); if (syscall_nr < 0) return; - if (!test_bit(syscall_nr, enabled_exit_syscalls)) + if (!test_bit(syscall_nr, tr->enabled_exit_syscalls)) return; sys_data = syscall_nr_to_meta(syscall_nr); if (!sys_data) return; - event = trace_current_buffer_lock_reserve(&buffer, + buffer = tr->trace_buffer.buffer; + event = trace_buffer_lock_reserve(buffer, sys_data->exit_event->event.type, sizeof(*entry), 0, 0); if (!event) return; @@ -337,8 +370,10 @@ void ftrace_syscall_exit(void *ignore, struct pt_regs *regs, long ret) trace_current_buffer_unlock_commit(buffer, event, 0, 0); } -int reg_event_syscall_enter(struct ftrace_event_call *call) +static int reg_event_syscall_enter(struct ftrace_event_file *file, + struct ftrace_event_call *call) { + struct trace_array *tr = file->tr; int ret = 0; int num; @@ -346,33 +381,37 @@ int reg_event_syscall_enter(struct ftrace_event_call *call) if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) return -ENOSYS; mutex_lock(&syscall_trace_lock); - if (!sys_refcount_enter) - ret = register_trace_sys_enter(ftrace_syscall_enter, NULL); + if (!tr->sys_refcount_enter) + ret = register_trace_sys_enter(ftrace_syscall_enter, tr); if (!ret) { - set_bit(num, enabled_enter_syscalls); - sys_refcount_enter++; + set_bit(num, tr->enabled_enter_syscalls); + tr->sys_refcount_enter++; } mutex_unlock(&syscall_trace_lock); return ret; } -void unreg_event_syscall_enter(struct ftrace_event_call *call) +static void unreg_event_syscall_enter(struct ftrace_event_file *file, + struct ftrace_event_call *call) { + struct trace_array *tr = file->tr; int num; num = ((struct syscall_metadata *)call->data)->syscall_nr; if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) return; mutex_lock(&syscall_trace_lock); - sys_refcount_enter--; - clear_bit(num, enabled_enter_syscalls); - if (!sys_refcount_enter) - unregister_trace_sys_enter(ftrace_syscall_enter, NULL); + tr->sys_refcount_enter--; + clear_bit(num, tr->enabled_enter_syscalls); + if (!tr->sys_refcount_enter) + unregister_trace_sys_enter(ftrace_syscall_enter, tr); mutex_unlock(&syscall_trace_lock); } -int reg_event_syscall_exit(struct ftrace_event_call *call) +static int reg_event_syscall_exit(struct ftrace_event_file *file, + struct ftrace_event_call *call) { + struct trace_array *tr = file->tr; int ret = 0; int num; @@ -380,28 +419,30 @@ int reg_event_syscall_exit(struct ftrace_event_call *call) if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) return -ENOSYS; mutex_lock(&syscall_trace_lock); - if (!sys_refcount_exit) - ret = register_trace_sys_exit(ftrace_syscall_exit, NULL); + if (!tr->sys_refcount_exit) + ret = register_trace_sys_exit(ftrace_syscall_exit, tr); if (!ret) { - set_bit(num, enabled_exit_syscalls); - sys_refcount_exit++; + set_bit(num, tr->enabled_exit_syscalls); + tr->sys_refcount_exit++; } mutex_unlock(&syscall_trace_lock); return ret; } -void unreg_event_syscall_exit(struct ftrace_event_call *call) +static void unreg_event_syscall_exit(struct ftrace_event_file *file, + struct ftrace_event_call *call) { + struct trace_array *tr = file->tr; int num; num = ((struct syscall_metadata *)call->data)->syscall_nr; if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) return; mutex_lock(&syscall_trace_lock); - sys_refcount_exit--; - clear_bit(num, enabled_exit_syscalls); - if (!sys_refcount_exit) - unregister_trace_sys_exit(ftrace_syscall_exit, NULL); + tr->sys_refcount_exit--; + clear_bit(num, tr->enabled_exit_syscalls); + if (!tr->sys_refcount_exit) + unregister_trace_sys_exit(ftrace_syscall_exit, tr); mutex_unlock(&syscall_trace_lock); } @@ -438,7 +479,7 @@ struct trace_event_functions exit_syscall_print_funcs = { .trace = print_syscall_exit, }; -struct ftrace_event_class event_class_syscall_enter = { +struct ftrace_event_class __refdata event_class_syscall_enter = { .system = "syscalls", .reg = syscall_enter_register, .define_fields = syscall_enter_define_fields, @@ -446,7 +487,7 @@ struct ftrace_event_class event_class_syscall_enter = { .raw_init = init_syscall_trace, }; -struct ftrace_event_class event_class_syscall_exit = { +struct ftrace_event_class __refdata event_class_syscall_exit = { .system = "syscalls", .reg = syscall_exit_register, .define_fields = syscall_exit_define_fields, @@ -459,7 +500,7 @@ unsigned long __init __weak arch_syscall_addr(int nr) return (unsigned long)sys_call_table[nr]; } -int __init init_ftrace_syscalls(void) +static int __init init_ftrace_syscalls(void) { struct syscall_metadata *meta; unsigned long addr; @@ -502,7 +543,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) int rctx; int size; - syscall_nr = syscall_get_nr(current, regs); + syscall_nr = trace_get_syscall_nr(current, regs); if (syscall_nr < 0) return; if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) @@ -578,7 +619,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) int rctx; int size; - syscall_nr = syscall_get_nr(current, regs); + syscall_nr = trace_get_syscall_nr(current, regs); if (syscall_nr < 0) return; if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) @@ -652,11 +693,13 @@ static void perf_sysexit_disable(struct ftrace_event_call *call) static int syscall_enter_register(struct ftrace_event_call *event, enum trace_reg type, void *data) { + struct ftrace_event_file *file = data; + switch (type) { case TRACE_REG_REGISTER: - return reg_event_syscall_enter(event); + return reg_event_syscall_enter(file, event); case TRACE_REG_UNREGISTER: - unreg_event_syscall_enter(event); + unreg_event_syscall_enter(file, event); return 0; #ifdef CONFIG_PERF_EVENTS @@ -678,11 +721,13 @@ static int syscall_enter_register(struct ftrace_event_call *event, static int syscall_exit_register(struct ftrace_event_call *event, enum trace_reg type, void *data) { + struct ftrace_event_file *file = data; + switch (type) { case TRACE_REG_REGISTER: - return reg_event_syscall_exit(event); + return reg_event_syscall_exit(file, event); case TRACE_REG_UNREGISTER: - unreg_event_syscall_exit(event); + unreg_event_syscall_exit(file, event); return 0; #ifdef CONFIG_PERF_EVENTS diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index c86e6d4f67fb..32494fb0ee64 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -28,20 +28,33 @@ #define UPROBE_EVENT_SYSTEM "uprobes" +struct uprobe_trace_entry_head { + struct trace_entry ent; + unsigned long vaddr[]; +}; + +#define SIZEOF_TRACE_ENTRY(is_return) \ + (sizeof(struct uprobe_trace_entry_head) + \ + sizeof(unsigned long) * (is_return ? 2 : 1)) + +#define DATAOF_TRACE_ENTRY(entry, is_return) \ + ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return)) + +struct trace_uprobe_filter { + rwlock_t rwlock; + int nr_systemwide; + struct list_head perf_events; +}; + /* * uprobe event core functions */ -struct trace_uprobe; -struct uprobe_trace_consumer { - struct uprobe_consumer cons; - struct trace_uprobe *tu; -}; - struct trace_uprobe { struct list_head list; struct ftrace_event_class class; struct ftrace_event_call call; - struct uprobe_trace_consumer *consumer; + struct trace_uprobe_filter filter; + struct uprobe_consumer consumer; struct inode *inode; char *filename; unsigned long offset; @@ -63,12 +76,31 @@ static DEFINE_MUTEX(uprobe_lock); static LIST_HEAD(uprobe_list); static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); +static int uretprobe_dispatcher(struct uprobe_consumer *con, + unsigned long func, struct pt_regs *regs); + +static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) +{ + rwlock_init(&filter->rwlock); + filter->nr_systemwide = 0; + INIT_LIST_HEAD(&filter->perf_events); +} + +static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) +{ + return !filter->nr_systemwide && list_empty(&filter->perf_events); +} + +static inline bool is_ret_probe(struct trace_uprobe *tu) +{ + return tu->consumer.ret_handler != NULL; +} /* * Allocate new trace_uprobe and initialize it (including uprobes). */ static struct trace_uprobe * -alloc_trace_uprobe(const char *group, const char *event, int nargs) +alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) { struct trace_uprobe *tu; @@ -92,6 +124,10 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs) goto error; INIT_LIST_HEAD(&tu->list); + tu->consumer.handler = uprobe_dispatcher; + if (is_ret) + tu->consumer.ret_handler = uretprobe_dispatcher; + init_trace_uprobe_filter(&tu->filter); return tu; error: @@ -165,7 +201,7 @@ end: /* * Argument syntax: - * - Add uprobe: p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] + * - Add uprobe: p|r[:[GRP/]EVENT] PATH:SYMBOL [FETCHARGS] * * - Remove uprobe: -:[GRP/]EVENT */ @@ -177,20 +213,23 @@ static int create_trace_uprobe(int argc, char **argv) char buf[MAX_EVENT_NAME_LEN]; struct path path; unsigned long offset; - bool is_delete; + bool is_delete, is_return; int i, ret; inode = NULL; ret = 0; is_delete = false; + is_return = false; event = NULL; group = NULL; /* argc must be >= 1 */ if (argv[0][0] == '-') is_delete = true; + else if (argv[0][0] == 'r') + is_return = true; else if (argv[0][0] != 'p') { - pr_info("Probe definition must be started with 'p' or '-'.\n"); + pr_info("Probe definition must be started with 'p', 'r' or '-'.\n"); return -EINVAL; } @@ -253,12 +292,18 @@ static int create_trace_uprobe(int argc, char **argv) if (ret) goto fail_address_parse; + inode = igrab(path.dentry->d_inode); + path_put(&path); + + if (!inode || !S_ISREG(inode->i_mode)) { + ret = -EINVAL; + goto fail_address_parse; + } + ret = kstrtoul(arg, 0, &offset); if (ret) goto fail_address_parse; - inode = igrab(path.dentry->d_inode); - argc -= 2; argv += 2; @@ -282,7 +327,7 @@ static int create_trace_uprobe(int argc, char **argv) kfree(tail); } - tu = alloc_trace_uprobe(group, event, argc); + tu = alloc_trace_uprobe(group, event, argc, is_return); if (IS_ERR(tu)) { pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); ret = PTR_ERR(tu); @@ -356,7 +401,7 @@ fail_address_parse: if (inode) iput(inode); - pr_info("Failed to parse address.\n"); + pr_info("Failed to parse address or file.\n"); return ret; } @@ -393,9 +438,10 @@ static void probes_seq_stop(struct seq_file *m, void *v) static int probes_seq_show(struct seq_file *m, void *v) { struct trace_uprobe *tu = v; + char c = is_ret_probe(tu) ? 'r' : 'p'; int i; - seq_printf(m, "p:%s/%s", tu->call.class->system, tu->call.name); + seq_printf(m, "%c:%s/%s", c, tu->call.class->system, tu->call.name); seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset); for (i = 0; i < tu->nr_args; i++) @@ -464,65 +510,81 @@ static const struct file_operations uprobe_profile_ops = { .release = seq_release, }; -/* uprobe handler */ -static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) +static void uprobe_trace_print(struct trace_uprobe *tu, + unsigned long func, struct pt_regs *regs) { struct uprobe_trace_entry_head *entry; struct ring_buffer_event *event; struct ring_buffer *buffer; - u8 *data; - int size, i, pc; - unsigned long irq_flags; + void *data; + int size, i; struct ftrace_event_call *call = &tu->call; - tu->nhit++; - - local_save_flags(irq_flags); - pc = preempt_count(); - - size = sizeof(*entry) + tu->size; - + size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); event = trace_current_buffer_lock_reserve(&buffer, call->event.type, - size, irq_flags, pc); + size + tu->size, 0, 0); if (!event) return; entry = ring_buffer_event_data(event); - entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); - data = (u8 *)&entry[1]; + if (is_ret_probe(tu)) { + entry->vaddr[0] = func; + entry->vaddr[1] = instruction_pointer(regs); + data = DATAOF_TRACE_ENTRY(entry, true); + } else { + entry->vaddr[0] = instruction_pointer(regs); + data = DATAOF_TRACE_ENTRY(entry, false); + } + for (i = 0; i < tu->nr_args; i++) call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); if (!filter_current_check_discard(buffer, call, entry, event)) - trace_buffer_unlock_commit(buffer, event, irq_flags, pc); + trace_buffer_unlock_commit(buffer, event, 0, 0); +} + +/* uprobe handler */ +static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + if (!is_ret_probe(tu)) + uprobe_trace_print(tu, 0, regs); + return 0; +} + +static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, + struct pt_regs *regs) +{ + uprobe_trace_print(tu, func, regs); } /* Event entry printers */ static enum print_line_t print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) { - struct uprobe_trace_entry_head *field; + struct uprobe_trace_entry_head *entry; struct trace_seq *s = &iter->seq; struct trace_uprobe *tu; u8 *data; int i; - field = (struct uprobe_trace_entry_head *)iter->ent; + entry = (struct uprobe_trace_entry_head *)iter->ent; tu = container_of(event, struct trace_uprobe, call.event); - if (!trace_seq_printf(s, "%s: (", tu->call.name)) - goto partial; - - if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) - goto partial; - - if (!trace_seq_puts(s, ")")) - goto partial; + if (is_ret_probe(tu)) { + if (!trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", tu->call.name, + entry->vaddr[1], entry->vaddr[0])) + goto partial; + data = DATAOF_TRACE_ENTRY(entry, true); + } else { + if (!trace_seq_printf(s, "%s: (0x%lx)", tu->call.name, + entry->vaddr[0])) + goto partial; + data = DATAOF_TRACE_ENTRY(entry, false); + } - data = (u8 *)&field[1]; for (i = 0; i < tu->nr_args; i++) { if (!tu->args[i].type->print(s, tu->args[i].name, - data + tu->args[i].offset, field)) + data + tu->args[i].offset, entry)) goto partial; } @@ -533,56 +595,64 @@ partial: return TRACE_TYPE_PARTIAL_LINE; } -static int probe_event_enable(struct trace_uprobe *tu, int flag) +static inline bool is_trace_uprobe_enabled(struct trace_uprobe *tu) { - struct uprobe_trace_consumer *utc; - int ret = 0; + return tu->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE); +} - if (!tu->inode || tu->consumer) - return -EINTR; +typedef bool (*filter_func_t)(struct uprobe_consumer *self, + enum uprobe_filter_ctx ctx, + struct mm_struct *mm); + +static int +probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter) +{ + int ret = 0; - utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL); - if (!utc) + if (is_trace_uprobe_enabled(tu)) return -EINTR; - utc->cons.handler = uprobe_dispatcher; - utc->cons.filter = NULL; - ret = uprobe_register(tu->inode, tu->offset, &utc->cons); - if (ret) { - kfree(utc); - return ret; - } + WARN_ON(!uprobe_filter_is_empty(&tu->filter)); tu->flags |= flag; - utc->tu = tu; - tu->consumer = utc; + tu->consumer.filter = filter; + ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); + if (ret) + tu->flags &= ~flag; - return 0; + return ret; } static void probe_event_disable(struct trace_uprobe *tu, int flag) { - if (!tu->inode || !tu->consumer) + if (!is_trace_uprobe_enabled(tu)) return; - uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons); + WARN_ON(!uprobe_filter_is_empty(&tu->filter)); + + uprobe_unregister(tu->inode, tu->offset, &tu->consumer); tu->flags &= ~flag; - kfree(tu->consumer); - tu->consumer = NULL; } static int uprobe_event_define_fields(struct ftrace_event_call *event_call) { - int ret, i; + int ret, i, size; struct uprobe_trace_entry_head field; - struct trace_uprobe *tu = (struct trace_uprobe *)event_call->data; - - DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); + struct trace_uprobe *tu = event_call->data; + + if (is_ret_probe(tu)) { + DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); + DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); + size = SIZEOF_TRACE_ENTRY(true); + } else { + DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); + size = SIZEOF_TRACE_ENTRY(false); + } /* Set argument names as fields */ for (i = 0; i < tu->nr_args; i++) { ret = trace_define_field(event_call, tu->args[i].type->fmttype, tu->args[i].name, - sizeof(field) + tu->args[i].offset, + size + tu->args[i].offset, tu->args[i].type->size, tu->args[i].type->is_signed, FILTER_OTHER); @@ -600,8 +670,13 @@ static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len) int i; int pos = 0; - fmt = "(%lx)"; - arg = "REC->" FIELD_STRING_IP; + if (is_ret_probe(tu)) { + fmt = "(%lx <- %lx)"; + arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; + } else { + fmt = "(%lx)"; + arg = "REC->" FIELD_STRING_IP; + } /* When len=0, we just calculate the needed length */ @@ -642,49 +717,160 @@ static int set_print_fmt(struct trace_uprobe *tu) } #ifdef CONFIG_PERF_EVENTS -/* uprobe profile handler */ -static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) +static bool +__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) +{ + struct perf_event *event; + + if (filter->nr_systemwide) + return true; + + list_for_each_entry(event, &filter->perf_events, hw.tp_list) { + if (event->hw.tp_target->mm == mm) + return true; + } + + return false; +} + +static inline bool +uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event) +{ + return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm); +} + +static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event) +{ + bool done; + + write_lock(&tu->filter.rwlock); + if (event->hw.tp_target) { + /* + * event->parent != NULL means copy_process(), we can avoid + * uprobe_apply(). current->mm must be probed and we can rely + * on dup_mmap() which preserves the already installed bp's. + * + * attr.enable_on_exec means that exec/mmap will install the + * breakpoints we need. + */ + done = tu->filter.nr_systemwide || + event->parent || event->attr.enable_on_exec || + uprobe_filter_event(tu, event); + list_add(&event->hw.tp_list, &tu->filter.perf_events); + } else { + done = tu->filter.nr_systemwide; + tu->filter.nr_systemwide++; + } + write_unlock(&tu->filter.rwlock); + + if (!done) + uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); + + return 0; +} + +static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event) +{ + bool done; + + write_lock(&tu->filter.rwlock); + if (event->hw.tp_target) { + list_del(&event->hw.tp_list); + done = tu->filter.nr_systemwide || + (event->hw.tp_target->flags & PF_EXITING) || + uprobe_filter_event(tu, event); + } else { + tu->filter.nr_systemwide--; + done = tu->filter.nr_systemwide; + } + write_unlock(&tu->filter.rwlock); + + if (!done) + uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); + + return 0; +} + +static bool uprobe_perf_filter(struct uprobe_consumer *uc, + enum uprobe_filter_ctx ctx, struct mm_struct *mm) +{ + struct trace_uprobe *tu; + int ret; + + tu = container_of(uc, struct trace_uprobe, consumer); + read_lock(&tu->filter.rwlock); + ret = __uprobe_perf_filter(&tu->filter, mm); + read_unlock(&tu->filter.rwlock); + + return ret; +} + +static void uprobe_perf_print(struct trace_uprobe *tu, + unsigned long func, struct pt_regs *regs) { struct ftrace_event_call *call = &tu->call; struct uprobe_trace_entry_head *entry; struct hlist_head *head; - u8 *data; - int size, __size, i; - int rctx; + void *data; + int size, rctx, i; - __size = sizeof(*entry) + tu->size; - size = ALIGN(__size + sizeof(u32), sizeof(u64)); - size -= sizeof(u32); + size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); + size = ALIGN(size + tu->size + sizeof(u32), sizeof(u64)) - sizeof(u32); if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) return; preempt_disable(); + head = this_cpu_ptr(call->perf_events); + if (hlist_empty(head)) + goto out; entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); if (!entry) goto out; - entry->ip = uprobe_get_swbp_addr(task_pt_regs(current)); - data = (u8 *)&entry[1]; + if (is_ret_probe(tu)) { + entry->vaddr[0] = func; + entry->vaddr[1] = instruction_pointer(regs); + data = DATAOF_TRACE_ENTRY(entry, true); + } else { + entry->vaddr[0] = instruction_pointer(regs); + data = DATAOF_TRACE_ENTRY(entry, false); + } + for (i = 0; i < tu->nr_args; i++) call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); - head = this_cpu_ptr(call->perf_events); - perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head, NULL); - + perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); out: preempt_enable(); } + +/* uprobe profile handler */ +static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) +{ + if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) + return UPROBE_HANDLER_REMOVE; + + if (!is_ret_probe(tu)) + uprobe_perf_print(tu, 0, regs); + return 0; +} + +static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, + struct pt_regs *regs) +{ + uprobe_perf_print(tu, func, regs); +} #endif /* CONFIG_PERF_EVENTS */ static int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data) { - struct trace_uprobe *tu = (struct trace_uprobe *)event->data; + struct trace_uprobe *tu = event->data; switch (type) { case TRACE_REG_REGISTER: - return probe_event_enable(tu, TP_FLAG_TRACE); + return probe_event_enable(tu, TP_FLAG_TRACE, NULL); case TRACE_REG_UNREGISTER: probe_event_disable(tu, TP_FLAG_TRACE); @@ -692,11 +878,18 @@ int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, #ifdef CONFIG_PERF_EVENTS case TRACE_REG_PERF_REGISTER: - return probe_event_enable(tu, TP_FLAG_PROFILE); + return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter); case TRACE_REG_PERF_UNREGISTER: probe_event_disable(tu, TP_FLAG_PROFILE); return 0; + + case TRACE_REG_PERF_OPEN: + return uprobe_perf_open(tu, data); + + case TRACE_REG_PERF_CLOSE: + return uprobe_perf_close(tu, data); + #endif default: return 0; @@ -706,20 +899,35 @@ int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) { - struct uprobe_trace_consumer *utc; struct trace_uprobe *tu; + int ret = 0; - utc = container_of(con, struct uprobe_trace_consumer, cons); - tu = utc->tu; - if (!tu || tu->consumer != utc) - return 0; + tu = container_of(con, struct trace_uprobe, consumer); + tu->nhit++; + + if (tu->flags & TP_FLAG_TRACE) + ret |= uprobe_trace_func(tu, regs); + +#ifdef CONFIG_PERF_EVENTS + if (tu->flags & TP_FLAG_PROFILE) + ret |= uprobe_perf_func(tu, regs); +#endif + return ret; +} + +static int uretprobe_dispatcher(struct uprobe_consumer *con, + unsigned long func, struct pt_regs *regs) +{ + struct trace_uprobe *tu; + + tu = container_of(con, struct trace_uprobe, consumer); if (tu->flags & TP_FLAG_TRACE) - uprobe_trace_func(tu, regs); + uretprobe_trace_func(tu, func, regs); #ifdef CONFIG_PERF_EVENTS if (tu->flags & TP_FLAG_PROFILE) - uprobe_perf_func(tu, regs); + uretprobe_perf_func(tu, func, regs); #endif return 0; } diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index d96ba22dabfa..29f26540e9c9 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -112,7 +112,8 @@ tracepoint_entry_add_probe(struct tracepoint_entry *entry, int nr_probes = 0; struct tracepoint_func *old, *new; - WARN_ON(!probe); + if (WARN_ON(!probe)) + return ERR_PTR(-EINVAL); debug_print_probes(entry); old = entry->funcs; @@ -152,13 +153,18 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry, debug_print_probes(entry); /* (N -> M), (N > 1, M >= 0) probes */ - for (nr_probes = 0; old[nr_probes].func; nr_probes++) { - if (!probe || - (old[nr_probes].func == probe && - old[nr_probes].data == data)) - nr_del++; + if (probe) { + for (nr_probes = 0; old[nr_probes].func; nr_probes++) { + if (old[nr_probes].func == probe && + old[nr_probes].data == data) + nr_del++; + } } + /* + * If probe is NULL, then nr_probes = nr_del = 0, and then the + * entire entry will be removed. + */ if (nr_probes - nr_del == 0) { /* N -> 0, (N > 1) */ entry->funcs = NULL; @@ -173,8 +179,7 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry, if (new == NULL) return ERR_PTR(-ENOMEM); for (i = 0; old[i].func; i++) - if (probe && - (old[i].func != probe || old[i].data != data)) + if (old[i].func != probe || old[i].data != data) new[j++] = old[i]; new[nr_probes - nr_del].func = NULL; entry->refcount = nr_probes - nr_del; @@ -192,12 +197,11 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry, static struct tracepoint_entry *get_tracepoint(const char *name) { struct hlist_head *head; - struct hlist_node *node; struct tracepoint_entry *e; u32 hash = jhash(name, strlen(name), 0); head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)]; - hlist_for_each_entry(e, node, head, hlist) { + hlist_for_each_entry(e, head, hlist) { if (!strcmp(name, e->name)) return e; } @@ -211,13 +215,12 @@ static struct tracepoint_entry *get_tracepoint(const char *name) static struct tracepoint_entry *add_tracepoint(const char *name) { struct hlist_head *head; - struct hlist_node *node; struct tracepoint_entry *e; size_t name_len = strlen(name) + 1; u32 hash = jhash(name, name_len-1, 0); head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)]; - hlist_for_each_entry(e, node, head, hlist) { + hlist_for_each_entry(e, head, hlist) { if (!strcmp(name, e->name)) { printk(KERN_NOTICE "tracepoint %s busy\n", name); diff --git a/kernel/tsacct.c b/kernel/tsacct.c index 625df0b44690..a1dd9a1b1327 100644 --- a/kernel/tsacct.c +++ b/kernel/tsacct.c @@ -32,6 +32,7 @@ void bacct_add_tsk(struct user_namespace *user_ns, { const struct cred *tcred; struct timespec uptime, ts; + cputime_t utime, stime, utimescaled, stimescaled; u64 ac_etime; BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN); @@ -65,10 +66,15 @@ void bacct_add_tsk(struct user_namespace *user_ns, stats->ac_ppid = pid_alive(tsk) ? task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0; rcu_read_unlock(); - stats->ac_utime = cputime_to_usecs(tsk->utime); - stats->ac_stime = cputime_to_usecs(tsk->stime); - stats->ac_utimescaled = cputime_to_usecs(tsk->utimescaled); - stats->ac_stimescaled = cputime_to_usecs(tsk->stimescaled); + + task_cputime(tsk, &utime, &stime); + stats->ac_utime = cputime_to_usecs(utime); + stats->ac_stime = cputime_to_usecs(stime); + + task_cputime_scaled(tsk, &utimescaled, &stimescaled); + stats->ac_utimescaled = cputime_to_usecs(utimescaled); + stats->ac_stimescaled = cputime_to_usecs(stimescaled); + stats->ac_minflt = tsk->min_flt; stats->ac_majflt = tsk->maj_flt; @@ -115,11 +121,8 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) #undef KB #undef MB -/** - * acct_update_integrals - update mm integral fields in task_struct - * @tsk: task_struct for accounting - */ -void acct_update_integrals(struct task_struct *tsk) +static void __acct_update_integrals(struct task_struct *tsk, + cputime_t utime, cputime_t stime) { if (likely(tsk->mm)) { cputime_t time, dtime; @@ -128,7 +131,7 @@ void acct_update_integrals(struct task_struct *tsk) u64 delta; local_irq_save(flags); - time = tsk->stime + tsk->utime; + time = stime + utime; dtime = time - tsk->acct_timexpd; jiffies_to_timeval(cputime_to_jiffies(dtime), &value); delta = value.tv_sec; @@ -145,6 +148,27 @@ void acct_update_integrals(struct task_struct *tsk) } /** + * acct_update_integrals - update mm integral fields in task_struct + * @tsk: task_struct for accounting + */ +void acct_update_integrals(struct task_struct *tsk) +{ + cputime_t utime, stime; + + task_cputime(tsk, &utime, &stime); + __acct_update_integrals(tsk, utime, stime); +} + +/** + * acct_account_cputime - update mm integral after cputime update + * @tsk: task_struct for accounting + */ +void acct_account_cputime(struct task_struct *tsk) +{ + __acct_update_integrals(tsk, tsk->utime, tsk->stime); +} + +/** * acct_clear_integrals - clear the mm integral fields in task_struct * @tsk: task_struct whose accounting fields are cleared */ diff --git a/kernel/uid16.c b/kernel/uid16.c index d7948eb10225..f6c83d7ef000 100644 --- a/kernel/uid16.c +++ b/kernel/uid16.c @@ -18,67 +18,43 @@ SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group) { - long ret = sys_chown(filename, low2highuid(user), low2highgid(group)); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(3, ret, filename, user, group); - return ret; + return sys_chown(filename, low2highuid(user), low2highgid(group)); } SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group) { - long ret = sys_lchown(filename, low2highuid(user), low2highgid(group)); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(3, ret, filename, user, group); - return ret; + return sys_lchown(filename, low2highuid(user), low2highgid(group)); } SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group) { - long ret = sys_fchown(fd, low2highuid(user), low2highgid(group)); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(3, ret, fd, user, group); - return ret; + return sys_fchown(fd, low2highuid(user), low2highgid(group)); } SYSCALL_DEFINE2(setregid16, old_gid_t, rgid, old_gid_t, egid) { - long ret = sys_setregid(low2highgid(rgid), low2highgid(egid)); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(2, ret, rgid, egid); - return ret; + return sys_setregid(low2highgid(rgid), low2highgid(egid)); } SYSCALL_DEFINE1(setgid16, old_gid_t, gid) { - long ret = sys_setgid(low2highgid(gid)); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(1, ret, gid); - return ret; + return sys_setgid(low2highgid(gid)); } SYSCALL_DEFINE2(setreuid16, old_uid_t, ruid, old_uid_t, euid) { - long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid)); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(2, ret, ruid, euid); - return ret; + return sys_setreuid(low2highuid(ruid), low2highuid(euid)); } SYSCALL_DEFINE1(setuid16, old_uid_t, uid) { - long ret = sys_setuid(low2highuid(uid)); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(1, ret, uid); - return ret; + return sys_setuid(low2highuid(uid)); } SYSCALL_DEFINE3(setresuid16, old_uid_t, ruid, old_uid_t, euid, old_uid_t, suid) { - long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid), + return sys_setresuid(low2highuid(ruid), low2highuid(euid), low2highuid(suid)); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(3, ret, ruid, euid, suid); - return ret; } SYSCALL_DEFINE3(getresuid16, old_uid_t __user *, ruidp, old_uid_t __user *, euidp, old_uid_t __user *, suidp) @@ -100,11 +76,8 @@ SYSCALL_DEFINE3(getresuid16, old_uid_t __user *, ruidp, old_uid_t __user *, euid SYSCALL_DEFINE3(setresgid16, old_gid_t, rgid, old_gid_t, egid, old_gid_t, sgid) { - long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid), + return sys_setresgid(low2highgid(rgid), low2highgid(egid), low2highgid(sgid)); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(3, ret, rgid, egid, sgid); - return ret; } @@ -127,18 +100,12 @@ SYSCALL_DEFINE3(getresgid16, old_gid_t __user *, rgidp, old_gid_t __user *, egid SYSCALL_DEFINE1(setfsuid16, old_uid_t, uid) { - long ret = sys_setfsuid(low2highuid(uid)); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(1, ret, uid); - return ret; + return sys_setfsuid(low2highuid(uid)); } SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid) { - long ret = sys_setfsgid(low2highgid(gid)); - /* avoid REGPARM breakage on x86: */ - asmlinkage_protect(1, ret, gid); - return ret; + return sys_setfsgid(low2highgid(gid)); } static int groups16_to_user(old_gid_t __user *grouplist, diff --git a/kernel/user-return-notifier.c b/kernel/user-return-notifier.c index 1744bb80f1fb..394f70b17162 100644 --- a/kernel/user-return-notifier.c +++ b/kernel/user-return-notifier.c @@ -34,11 +34,11 @@ EXPORT_SYMBOL_GPL(user_return_notifier_unregister); void fire_user_return_notifiers(void) { struct user_return_notifier *urn; - struct hlist_node *tmp1, *tmp2; + struct hlist_node *tmp2; struct hlist_head *head; head = &get_cpu_var(return_notifier_list); - hlist_for_each_entry_safe(urn, tmp1, tmp2, head, link) + hlist_for_each_entry_safe(urn, tmp2, head, link) urn->on_user_return(urn); put_cpu_var(return_notifier_list); } diff --git a/kernel/user.c b/kernel/user.c index 33acb5e53a5f..69b4c3d48cde 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -16,7 +16,7 @@ #include <linux/interrupt.h> #include <linux/export.h> #include <linux/user_namespace.h> -#include <linux/proc_fs.h> +#include <linux/proc_ns.h> /* * userns count is 1 for root user, 1 for init_uts_ns, @@ -47,12 +47,12 @@ struct user_namespace init_user_ns = { .count = 4294967295U, }, }, - .kref = { - .refcount = ATOMIC_INIT(3), - }, + .count = ATOMIC_INIT(3), .owner = GLOBAL_ROOT_UID, .group = GLOBAL_ROOT_GID, .proc_inum = PROC_USER_INIT_INO, + .may_mount_sysfs = true, + .may_mount_proc = true, }; EXPORT_SYMBOL_GPL(init_user_ns); @@ -107,9 +107,8 @@ static void uid_hash_remove(struct user_struct *up) static struct user_struct *uid_hash_find(kuid_t uid, struct hlist_head *hashent) { struct user_struct *user; - struct hlist_node *h; - hlist_for_each_entry(user, h, hashent, uidhash_node) { + hlist_for_each_entry(user, hashent, uidhash_node) { if (uid_eq(user->uid, uid)) { atomic_inc(&user->__count); return user; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 2b042c42fbc4..d8c30db06c5b 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -9,7 +9,7 @@ #include <linux/nsproxy.h> #include <linux/slab.h> #include <linux/user_namespace.h> -#include <linux/proc_fs.h> +#include <linux/proc_ns.h> #include <linux/highuid.h> #include <linux/cred.h> #include <linux/securebits.h> @@ -21,10 +21,12 @@ #include <linux/uaccess.h> #include <linux/ctype.h> #include <linux/projid.h> +#include <linux/fs_struct.h> static struct kmem_cache *user_ns_cachep __read_mostly; -static bool new_idmap_permitted(struct user_namespace *ns, int cap_setid, +static bool new_idmap_permitted(const struct file *file, + struct user_namespace *ns, int cap_setid, struct uid_gid_map *map); static void set_cred_user_ns(struct cred *cred, struct user_namespace *user_ns) @@ -60,6 +62,15 @@ int create_user_ns(struct cred *new) kgid_t group = new->egid; int ret; + /* + * Verify that we can not violate the policy of which files + * may be accessed that is specified by the root directory, + * by verifing that the root directory is at the root of the + * mount namespace which allows all files to be accessed. + */ + if (current_chrooted()) + return -EPERM; + /* The creator needs a mapping in the parent user namespace * or else we won't be able to reasonably tell userspace who * created a user_namespace. @@ -78,7 +89,7 @@ int create_user_ns(struct cred *new) return ret; } - kref_init(&ns->kref); + atomic_set(&ns->count, 1); /* Leave the new->user_ns reference with the new user namespace. */ ns->parent = parent_ns; ns->owner = owner; @@ -86,6 +97,8 @@ int create_user_ns(struct cred *new) set_cred_user_ns(new, ns); + update_mnt_policy(ns); + return 0; } @@ -104,15 +117,16 @@ int unshare_userns(unsigned long unshare_flags, struct cred **new_cred) return create_user_ns(cred); } -void free_user_ns(struct kref *kref) +void free_user_ns(struct user_namespace *ns) { - struct user_namespace *parent, *ns = - container_of(kref, struct user_namespace, kref); + struct user_namespace *parent; - parent = ns->parent; - proc_free_inum(ns->proc_inum); - kmem_cache_free(user_ns_cachep, ns); - put_user_ns(parent); + do { + parent = ns->parent; + proc_free_inum(ns->proc_inum); + kmem_cache_free(user_ns_cachep, ns); + ns = parent; + } while (atomic_dec_and_test(&parent->count)); } EXPORT_SYMBOL(free_user_ns); @@ -519,6 +533,42 @@ struct seq_operations proc_projid_seq_operations = { .show = projid_m_show, }; +static bool mappings_overlap(struct uid_gid_map *new_map, struct uid_gid_extent *extent) +{ + u32 upper_first, lower_first, upper_last, lower_last; + unsigned idx; + + upper_first = extent->first; + lower_first = extent->lower_first; + upper_last = upper_first + extent->count - 1; + lower_last = lower_first + extent->count - 1; + + for (idx = 0; idx < new_map->nr_extents; idx++) { + u32 prev_upper_first, prev_lower_first; + u32 prev_upper_last, prev_lower_last; + struct uid_gid_extent *prev; + + prev = &new_map->extent[idx]; + + prev_upper_first = prev->first; + prev_lower_first = prev->lower_first; + prev_upper_last = prev_upper_first + prev->count - 1; + prev_lower_last = prev_lower_first + prev->count - 1; + + /* Does the upper range intersect a previous extent? */ + if ((prev_upper_first <= upper_last) && + (prev_upper_last >= upper_first)) + return true; + + /* Does the lower range intersect a previous extent? */ + if ((prev_lower_first <= lower_last) && + (prev_lower_last >= lower_first)) + return true; + } + return false; +} + + static DEFINE_MUTEX(id_map_mutex); static ssize_t map_write(struct file *file, const char __user *buf, @@ -531,7 +581,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, struct user_namespace *ns = seq->private; struct uid_gid_map new_map; unsigned idx; - struct uid_gid_extent *extent, *last = NULL; + struct uid_gid_extent *extent = NULL; unsigned long page = 0; char *kbuf, *pos, *next_line; ssize_t ret = -EINVAL; @@ -563,10 +613,10 @@ static ssize_t map_write(struct file *file, const char __user *buf, if (map->nr_extents != 0) goto out; - /* Require the appropriate privilege CAP_SETUID or CAP_SETGID - * over the user namespace in order to set the id mapping. + /* + * Adjusting namespace settings requires capabilities on the target. */ - if (cap_valid(cap_setid) && !ns_capable(ns, cap_setid)) + if (cap_valid(cap_setid) && !file_ns_capable(file, ns, CAP_SYS_ADMIN)) goto out; /* Get a buffer */ @@ -634,14 +684,11 @@ static ssize_t map_write(struct file *file, const char __user *buf, if ((extent->lower_first + extent->count) <= extent->lower_first) goto out; - /* For now only accept extents that are strictly in order */ - if (last && - (((last->first + last->count) > extent->first) || - ((last->lower_first + last->count) > extent->lower_first))) + /* Do the ranges in extent overlap any previous extents? */ + if (mappings_overlap(&new_map, extent)) goto out; new_map.nr_extents++; - last = extent; /* Fail if the file contains too many extents */ if ((new_map.nr_extents == UID_GID_MAP_MAX_EXTENTS) && @@ -654,7 +701,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, ret = -EPERM; /* Validate the user is allowed to use user id's mapped to. */ - if (!new_idmap_permitted(ns, cap_setid, &new_map)) + if (!new_idmap_permitted(file, ns, cap_setid, &new_map)) goto out; /* Map the lower ids from the parent user namespace to the @@ -741,7 +788,8 @@ ssize_t proc_projid_map_write(struct file *file, const char __user *buf, size_t &ns->projid_map, &ns->parent->projid_map); } -static bool new_idmap_permitted(struct user_namespace *ns, int cap_setid, +static bool new_idmap_permitted(const struct file *file, + struct user_namespace *ns, int cap_setid, struct uid_gid_map *new_map) { /* Allow mapping to your own filesystem ids */ @@ -749,12 +797,12 @@ static bool new_idmap_permitted(struct user_namespace *ns, int cap_setid, u32 id = new_map->extent[0].lower_first; if (cap_setid == CAP_SETUID) { kuid_t uid = make_kuid(ns->parent, id); - if (uid_eq(uid, current_fsuid())) + if (uid_eq(uid, file->f_cred->fsuid)) return true; } else if (cap_setid == CAP_SETGID) { kgid_t gid = make_kgid(ns->parent, id); - if (gid_eq(gid, current_fsgid())) + if (gid_eq(gid, file->f_cred->fsgid)) return true; } } @@ -765,8 +813,10 @@ static bool new_idmap_permitted(struct user_namespace *ns, int cap_setid, /* Allow the specified ids if we have the appropriate capability * (CAP_SETUID or CAP_SETGID) over the parent user namespace. + * And the opener of the id file also had the approprpiate capability. */ - if (ns_capable(ns->parent, cap_setid)) + if (ns_capable(ns->parent, cap_setid) && + file_ns_capable(file, ns->parent, cap_setid)) return true; return false; @@ -803,6 +853,9 @@ static int userns_install(struct nsproxy *nsproxy, void *ns) if (atomic_read(¤t->mm->mm_users) > 1) return -EINVAL; + if (current->fs->users != 1) + return -EINVAL; + if (!ns_capable(user_ns, CAP_SYS_ADMIN)) return -EPERM; diff --git a/kernel/utsname.c b/kernel/utsname.c index 08b197e8c485..2fc8576efaa8 100644 --- a/kernel/utsname.c +++ b/kernel/utsname.c @@ -15,7 +15,7 @@ #include <linux/err.h> #include <linux/slab.h> #include <linux/user_namespace.h> -#include <linux/proc_fs.h> +#include <linux/proc_ns.h> static struct uts_namespace *create_uts_ns(void) { @@ -30,7 +30,7 @@ static struct uts_namespace *create_uts_ns(void) /* * Clone a new ns copying an original utsname, setting refcount to 1 * @old_ns: namespace to clone - * Return NULL on error (failure to kmalloc), new ns otherwise + * Return ERR_PTR(-ENOMEM) on error (failure to kmalloc), new ns otherwise */ static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns, struct uts_namespace *old_ns) diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c index 63da38c2d820..4f69f9a5e221 100644 --- a/kernel/utsname_sysctl.c +++ b/kernel/utsname_sysctl.c @@ -15,6 +15,8 @@ #include <linux/sysctl.h> #include <linux/wait.h> +#ifdef CONFIG_PROC_SYSCTL + static void *get_uts(ctl_table *table, int write) { char *which = table->data; @@ -38,7 +40,6 @@ static void put_uts(ctl_table *table, int write, void *which) up_write(&uts_sem); } -#ifdef CONFIG_PROC_SYSCTL /* * Special case of dostring for the UTS structure. This has locks * to observe. Should this be in kernel/sys.c ???? diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 75a2ab3d0b02..05039e348f07 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -23,6 +23,7 @@ #include <linux/module.h> #include <linux/sysctl.h> #include <linux/smpboot.h> +#include <linux/sched/rt.h> #include <asm/irq_regs.h> #include <linux/kvm_para.h> @@ -112,9 +113,9 @@ static int get_softlockup_thresh(void) * resolution, and we don't need to waste time with a big divide when * 2^30ns == 1.074s. */ -static unsigned long get_timestamp(int this_cpu) +static unsigned long get_timestamp(void) { - return cpu_clock(this_cpu) >> 30LL; /* 2^30 ~= 10^9 */ + return local_clock() >> 30LL; /* 2^30 ~= 10^9 */ } static void set_sample_period(void) @@ -132,9 +133,7 @@ static void set_sample_period(void) /* Commands for resetting the watchdog */ static void __touch_watchdog(void) { - int this_cpu = smp_processor_id(); - - __this_cpu_write(watchdog_touch_ts, get_timestamp(this_cpu)); + __this_cpu_write(watchdog_touch_ts, get_timestamp()); } void touch_softlockup_watchdog(void) @@ -195,7 +194,7 @@ static int is_hardlockup(void) static int is_softlockup(unsigned long touch_ts) { - unsigned long now = get_timestamp(smp_processor_id()); + unsigned long now = get_timestamp(); /* Warn about unreasonable delays: */ if (time_after(now, touch_ts + get_softlockup_thresh())) @@ -518,6 +517,11 @@ int proc_dowatchdog(struct ctl_table *table, int write, return ret; set_sample_period(); + /* + * Watchdog threads shouldn't be enabled if they are + * disabled. The 'watchdog_disabled' variable check in + * watchdog_*_all_cpus() function takes care of this. + */ if (watchdog_enabled && watchdog_thresh) watchdog_enable_all_cpus(); else diff --git a/kernel/workqueue.c b/kernel/workqueue.c index fbc6576a83c3..4aa9f5bc6b2d 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -41,32 +41,35 @@ #include <linux/debug_locks.h> #include <linux/lockdep.h> #include <linux/idr.h> +#include <linux/jhash.h> +#include <linux/hashtable.h> +#include <linux/rculist.h> +#include <linux/nodemask.h> +#include <linux/moduleparam.h> +#include <linux/uaccess.h> -#include "workqueue_sched.h" +#include "workqueue_internal.h" enum { /* - * global_cwq flags + * worker_pool flags * - * A bound gcwq is either associated or disassociated with its CPU. + * A bound pool is either associated or disassociated with its CPU. * While associated (!DISASSOCIATED), all workers are bound to the * CPU and none has %WORKER_UNBOUND set and concurrency management * is in effect. * * While DISASSOCIATED, the cpu may be offline and all workers have * %WORKER_UNBOUND set and concurrency management disabled, and may - * be executing on any CPU. The gcwq behaves as an unbound one. + * be executing on any CPU. The pool behaves as an unbound one. * - * Note that DISASSOCIATED can be flipped only while holding - * assoc_mutex of all pools on the gcwq to avoid changing binding - * state while create_worker() is in progress. + * Note that DISASSOCIATED should be flipped only while holding + * manager_mutex to avoid changing binding state while + * create_worker() is in progress. */ - GCWQ_DISASSOCIATED = 1 << 0, /* cpu can't serve workers */ - GCWQ_FREEZING = 1 << 1, /* freeze in progress */ - - /* pool flags */ POOL_MANAGE_WORKERS = 1 << 0, /* need to manage workers */ - POOL_MANAGING_WORKERS = 1 << 1, /* managing workers */ + POOL_DISASSOCIATED = 1 << 2, /* cpu can't serve workers */ + POOL_FREEZING = 1 << 3, /* freeze in progress */ /* worker flags */ WORKER_STARTED = 1 << 0, /* started */ @@ -75,15 +78,15 @@ enum { WORKER_PREP = 1 << 3, /* preparing to run works */ WORKER_CPU_INTENSIVE = 1 << 6, /* cpu intensive */ WORKER_UNBOUND = 1 << 7, /* worker is unbound */ + WORKER_REBOUND = 1 << 8, /* worker was rebound */ - WORKER_NOT_RUNNING = WORKER_PREP | WORKER_UNBOUND | - WORKER_CPU_INTENSIVE, + WORKER_NOT_RUNNING = WORKER_PREP | WORKER_CPU_INTENSIVE | + WORKER_UNBOUND | WORKER_REBOUND, - NR_WORKER_POOLS = 2, /* # worker pools per gcwq */ + NR_STD_WORKER_POOLS = 2, /* # standard pools per cpu */ + UNBOUND_POOL_HASH_ORDER = 6, /* hashed by pool->attrs */ BUSY_WORKER_HASH_ORDER = 6, /* 64 pointers */ - BUSY_WORKER_HASH_SIZE = 1 << BUSY_WORKER_HASH_ORDER, - BUSY_WORKER_HASH_MASK = BUSY_WORKER_HASH_SIZE - 1, MAX_IDLE_WORKERS_RATIO = 4, /* 1/4 of busy can be idle */ IDLE_WORKER_TIMEOUT = 300 * HZ, /* keep idle ones for 5 mins */ @@ -100,6 +103,8 @@ enum { */ RESCUER_NICE_LEVEL = -20, HIGHPRI_NICE_LEVEL = -20, + + WQ_NAME_LEN = 24, }; /* @@ -111,48 +116,34 @@ enum { * P: Preemption protected. Disabling preemption is enough and should * only be modified and accessed from the local cpu. * - * L: gcwq->lock protected. Access with gcwq->lock held. + * L: pool->lock protected. Access with pool->lock held. + * + * X: During normal operation, modification requires pool->lock and should + * be done only from local cpu. Either disabling preemption on local + * cpu or grabbing pool->lock is enough for read access. If + * POOL_DISASSOCIATED is set, it's identical to L. + * + * MG: pool->manager_mutex and pool->lock protected. Writes require both + * locks. Reads can happen under either lock. * - * X: During normal operation, modification requires gcwq->lock and - * should be done only from local cpu. Either disabling preemption - * on local cpu or grabbing gcwq->lock is enough for read access. - * If GCWQ_DISASSOCIATED is set, it's identical to L. + * PL: wq_pool_mutex protected. * - * F: wq->flush_mutex protected. + * PR: wq_pool_mutex protected for writes. Sched-RCU protected for reads. * - * W: workqueue_lock protected. + * WQ: wq->mutex protected. + * + * WR: wq->mutex protected for writes. Sched-RCU protected for reads. + * + * MD: wq_mayday_lock protected. */ -struct global_cwq; -struct worker_pool; - -/* - * The poor guys doing the actual heavy lifting. All on-duty workers - * are either serving the manager role, on idle list or on busy hash. - */ -struct worker { - /* on idle list while idle, on busy hash table while busy */ - union { - struct list_head entry; /* L: while idle */ - struct hlist_node hentry; /* L: while busy */ - }; - - struct work_struct *current_work; /* L: work being processed */ - struct cpu_workqueue_struct *current_cwq; /* L: current_work's cwq */ - struct list_head scheduled; /* L: scheduled works */ - struct task_struct *task; /* I: worker task */ - struct worker_pool *pool; /* I: the associated pool */ - /* 64 bytes boundary on 64bit, 32 on 32bit */ - unsigned long last_active; /* L: last active timestamp */ - unsigned int flags; /* X: flags */ - int id; /* I: worker id */ - - /* for rebinding worker to CPU */ - struct work_struct rebind_work; /* L: for busy worker */ -}; +/* struct worker is defined in workqueue_internal.h */ struct worker_pool { - struct global_cwq *gcwq; /* I: the owning gcwq */ + spinlock_t lock; /* the pool lock */ + int cpu; /* I: the associated cpu */ + int node; /* I: the associated node ID */ + int id; /* I: pool ID */ unsigned int flags; /* X: flags */ struct list_head worklist; /* L: list of pending works */ @@ -165,107 +156,145 @@ struct worker_pool { struct timer_list idle_timer; /* L: worker idle timeout */ struct timer_list mayday_timer; /* L: SOS timer for workers */ - struct mutex assoc_mutex; /* protect GCWQ_DISASSOCIATED */ - struct ida worker_ida; /* L: for worker IDs */ -}; + /* a workers is either on busy_hash or idle_list, or the manager */ + DECLARE_HASHTABLE(busy_hash, BUSY_WORKER_HASH_ORDER); + /* L: hash of busy workers */ -/* - * Global per-cpu workqueue. There's one and only one for each cpu - * and all works are queued and processed here regardless of their - * target workqueues. - */ -struct global_cwq { - spinlock_t lock; /* the gcwq lock */ - unsigned int cpu; /* I: the associated cpu */ - unsigned int flags; /* L: GCWQ_* flags */ + /* see manage_workers() for details on the two manager mutexes */ + struct mutex manager_arb; /* manager arbitration */ + struct mutex manager_mutex; /* manager exclusion */ + struct idr worker_idr; /* MG: worker IDs and iteration */ - /* workers are chained either in busy_hash or pool idle_list */ - struct hlist_head busy_hash[BUSY_WORKER_HASH_SIZE]; - /* L: hash of busy workers */ + struct workqueue_attrs *attrs; /* I: worker attributes */ + struct hlist_node hash_node; /* PL: unbound_pool_hash node */ + int refcnt; /* PL: refcnt for unbound pools */ + + /* + * The current concurrency level. As it's likely to be accessed + * from other CPUs during try_to_wake_up(), put it in a separate + * cacheline. + */ + atomic_t nr_running ____cacheline_aligned_in_smp; - struct worker_pool pools[NR_WORKER_POOLS]; - /* normal and highpri pools */ + /* + * Destruction of pool is sched-RCU protected to allow dereferences + * from get_work_pool(). + */ + struct rcu_head rcu; } ____cacheline_aligned_in_smp; /* - * The per-CPU workqueue. The lower WORK_STRUCT_FLAG_BITS of - * work_struct->data are used for flags and thus cwqs need to be - * aligned at two's power of the number of flag bits. + * The per-pool workqueue. While queued, the lower WORK_STRUCT_FLAG_BITS + * of work_struct->data are used for flags and the remaining high bits + * point to the pwq; thus, pwqs need to be aligned at two's power of the + * number of flag bits. */ -struct cpu_workqueue_struct { +struct pool_workqueue { struct worker_pool *pool; /* I: the associated pool */ struct workqueue_struct *wq; /* I: the owning workqueue */ int work_color; /* L: current color */ int flush_color; /* L: flushing color */ + int refcnt; /* L: reference count */ int nr_in_flight[WORK_NR_COLORS]; /* L: nr of in_flight works */ int nr_active; /* L: nr of active works */ int max_active; /* L: max active works */ struct list_head delayed_works; /* L: delayed works */ -}; + struct list_head pwqs_node; /* WR: node on wq->pwqs */ + struct list_head mayday_node; /* MD: node on wq->maydays */ + + /* + * Release of unbound pwq is punted to system_wq. See put_pwq() + * and pwq_unbound_release_workfn() for details. pool_workqueue + * itself is also sched-RCU protected so that the first pwq can be + * determined without grabbing wq->mutex. + */ + struct work_struct unbound_release_work; + struct rcu_head rcu; +} __aligned(1 << WORK_STRUCT_FLAG_BITS); /* * Structure used to wait for workqueue flush. */ struct wq_flusher { - struct list_head list; /* F: list of flushers */ - int flush_color; /* F: flush color waiting for */ + struct list_head list; /* WQ: list of flushers */ + int flush_color; /* WQ: flush color waiting for */ struct completion done; /* flush completion */ }; -/* - * All cpumasks are assumed to be always set on UP and thus can't be - * used to determine whether there's something to be done. - */ -#ifdef CONFIG_SMP -typedef cpumask_var_t mayday_mask_t; -#define mayday_test_and_set_cpu(cpu, mask) \ - cpumask_test_and_set_cpu((cpu), (mask)) -#define mayday_clear_cpu(cpu, mask) cpumask_clear_cpu((cpu), (mask)) -#define for_each_mayday_cpu(cpu, mask) for_each_cpu((cpu), (mask)) -#define alloc_mayday_mask(maskp, gfp) zalloc_cpumask_var((maskp), (gfp)) -#define free_mayday_mask(mask) free_cpumask_var((mask)) -#else -typedef unsigned long mayday_mask_t; -#define mayday_test_and_set_cpu(cpu, mask) test_and_set_bit(0, &(mask)) -#define mayday_clear_cpu(cpu, mask) clear_bit(0, &(mask)) -#define for_each_mayday_cpu(cpu, mask) if ((cpu) = 0, (mask)) -#define alloc_mayday_mask(maskp, gfp) true -#define free_mayday_mask(mask) do { } while (0) -#endif +struct wq_device; /* - * The externally visible workqueue abstraction is an array of - * per-CPU workqueues: + * The externally visible workqueue. It relays the issued work items to + * the appropriate worker_pool through its pool_workqueues. */ struct workqueue_struct { - unsigned int flags; /* W: WQ_* flags */ - union { - struct cpu_workqueue_struct __percpu *pcpu; - struct cpu_workqueue_struct *single; - unsigned long v; - } cpu_wq; /* I: cwq's */ - struct list_head list; /* W: list of all workqueues */ - - struct mutex flush_mutex; /* protects wq flushing */ - int work_color; /* F: current work color */ - int flush_color; /* F: current flush color */ - atomic_t nr_cwqs_to_flush; /* flush in progress */ - struct wq_flusher *first_flusher; /* F: first flusher */ - struct list_head flusher_queue; /* F: flush waiters */ - struct list_head flusher_overflow; /* F: flush overflow list */ - - mayday_mask_t mayday_mask; /* cpus requesting rescue */ + struct list_head pwqs; /* WR: all pwqs of this wq */ + struct list_head list; /* PL: list of all workqueues */ + + struct mutex mutex; /* protects this wq */ + int work_color; /* WQ: current work color */ + int flush_color; /* WQ: current flush color */ + atomic_t nr_pwqs_to_flush; /* flush in progress */ + struct wq_flusher *first_flusher; /* WQ: first flusher */ + struct list_head flusher_queue; /* WQ: flush waiters */ + struct list_head flusher_overflow; /* WQ: flush overflow list */ + + struct list_head maydays; /* MD: pwqs requesting rescue */ struct worker *rescuer; /* I: rescue worker */ - int nr_drainers; /* W: drain in progress */ - int saved_max_active; /* W: saved cwq max_active */ + int nr_drainers; /* WQ: drain in progress */ + int saved_max_active; /* WQ: saved pwq max_active */ + + struct workqueue_attrs *unbound_attrs; /* WQ: only for unbound wqs */ + struct pool_workqueue *dfl_pwq; /* WQ: only for unbound wqs */ + +#ifdef CONFIG_SYSFS + struct wq_device *wq_dev; /* I: for sysfs interface */ +#endif #ifdef CONFIG_LOCKDEP struct lockdep_map lockdep_map; #endif - char name[]; /* I: workqueue name */ + char name[WQ_NAME_LEN]; /* I: workqueue name */ + + /* hot fields used during command issue, aligned to cacheline */ + unsigned int flags ____cacheline_aligned; /* WQ: WQ_* flags */ + struct pool_workqueue __percpu *cpu_pwqs; /* I: per-cpu pwqs */ + struct pool_workqueue __rcu *numa_pwq_tbl[]; /* FR: unbound pwqs indexed by node */ }; +static struct kmem_cache *pwq_cache; + +static int wq_numa_tbl_len; /* highest possible NUMA node id + 1 */ +static cpumask_var_t *wq_numa_possible_cpumask; + /* possible CPUs of each node */ + +static bool wq_disable_numa; +module_param_named(disable_numa, wq_disable_numa, bool, 0444); + +static bool wq_numa_enabled; /* unbound NUMA affinity enabled */ + +/* buf for wq_update_unbound_numa_attrs(), protected by CPU hotplug exclusion */ +static struct workqueue_attrs *wq_update_unbound_numa_attrs_buf; + +static DEFINE_MUTEX(wq_pool_mutex); /* protects pools and workqueues list */ +static DEFINE_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */ + +static LIST_HEAD(workqueues); /* PL: list of all workqueues */ +static bool workqueue_freezing; /* PL: have wqs started freezing? */ + +/* the per-cpu worker pools */ +static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool [NR_STD_WORKER_POOLS], + cpu_worker_pools); + +static DEFINE_IDR(worker_pool_idr); /* PR: idr of all pools */ + +/* PL: hash of all unbound pools keyed by pool->attrs */ +static DEFINE_HASHTABLE(unbound_pool_hash, UNBOUND_POOL_HASH_ORDER); + +/* I: attributes used when instantiating standard unbound pools on demand */ +static struct workqueue_attrs *unbound_std_wq_attrs[NR_STD_WORKER_POOLS]; + struct workqueue_struct *system_wq __read_mostly; EXPORT_SYMBOL_GPL(system_wq); struct workqueue_struct *system_highpri_wq __read_mostly; @@ -277,65 +306,87 @@ EXPORT_SYMBOL_GPL(system_unbound_wq); struct workqueue_struct *system_freezable_wq __read_mostly; EXPORT_SYMBOL_GPL(system_freezable_wq); +static int worker_thread(void *__worker); +static void copy_workqueue_attrs(struct workqueue_attrs *to, + const struct workqueue_attrs *from); + #define CREATE_TRACE_POINTS #include <trace/events/workqueue.h> -#define for_each_worker_pool(pool, gcwq) \ - for ((pool) = &(gcwq)->pools[0]; \ - (pool) < &(gcwq)->pools[NR_WORKER_POOLS]; (pool)++) +#define assert_rcu_or_pool_mutex() \ + rcu_lockdep_assert(rcu_read_lock_sched_held() || \ + lockdep_is_held(&wq_pool_mutex), \ + "sched RCU or wq_pool_mutex should be held") -#define for_each_busy_worker(worker, i, pos, gcwq) \ - for (i = 0; i < BUSY_WORKER_HASH_SIZE; i++) \ - hlist_for_each_entry(worker, pos, &gcwq->busy_hash[i], hentry) +#define assert_rcu_or_wq_mutex(wq) \ + rcu_lockdep_assert(rcu_read_lock_sched_held() || \ + lockdep_is_held(&wq->mutex), \ + "sched RCU or wq->mutex should be held") -static inline int __next_gcwq_cpu(int cpu, const struct cpumask *mask, - unsigned int sw) -{ - if (cpu < nr_cpu_ids) { - if (sw & 1) { - cpu = cpumask_next(cpu, mask); - if (cpu < nr_cpu_ids) - return cpu; - } - if (sw & 2) - return WORK_CPU_UNBOUND; - } - return WORK_CPU_NONE; -} +#ifdef CONFIG_LOCKDEP +#define assert_manager_or_pool_lock(pool) \ + WARN_ONCE(debug_locks && \ + !lockdep_is_held(&(pool)->manager_mutex) && \ + !lockdep_is_held(&(pool)->lock), \ + "pool->manager_mutex or ->lock should be held") +#else +#define assert_manager_or_pool_lock(pool) do { } while (0) +#endif -static inline int __next_wq_cpu(int cpu, const struct cpumask *mask, - struct workqueue_struct *wq) -{ - return __next_gcwq_cpu(cpu, mask, !(wq->flags & WQ_UNBOUND) ? 1 : 2); -} +#define for_each_cpu_worker_pool(pool, cpu) \ + for ((pool) = &per_cpu(cpu_worker_pools, cpu)[0]; \ + (pool) < &per_cpu(cpu_worker_pools, cpu)[NR_STD_WORKER_POOLS]; \ + (pool)++) -/* - * CPU iterators +/** + * for_each_pool - iterate through all worker_pools in the system + * @pool: iteration cursor + * @pi: integer used for iteration * - * An extra gcwq is defined for an invalid cpu number - * (WORK_CPU_UNBOUND) to host workqueues which are not bound to any - * specific CPU. The following iterators are similar to - * for_each_*_cpu() iterators but also considers the unbound gcwq. + * This must be called either with wq_pool_mutex held or sched RCU read + * locked. If the pool needs to be used beyond the locking in effect, the + * caller is responsible for guaranteeing that the pool stays online. * - * for_each_gcwq_cpu() : possible CPUs + WORK_CPU_UNBOUND - * for_each_online_gcwq_cpu() : online CPUs + WORK_CPU_UNBOUND - * for_each_cwq_cpu() : possible CPUs for bound workqueues, - * WORK_CPU_UNBOUND for unbound workqueues + * The if/else clause exists only for the lockdep assertion and can be + * ignored. */ -#define for_each_gcwq_cpu(cpu) \ - for ((cpu) = __next_gcwq_cpu(-1, cpu_possible_mask, 3); \ - (cpu) < WORK_CPU_NONE; \ - (cpu) = __next_gcwq_cpu((cpu), cpu_possible_mask, 3)) +#define for_each_pool(pool, pi) \ + idr_for_each_entry(&worker_pool_idr, pool, pi) \ + if (({ assert_rcu_or_pool_mutex(); false; })) { } \ + else -#define for_each_online_gcwq_cpu(cpu) \ - for ((cpu) = __next_gcwq_cpu(-1, cpu_online_mask, 3); \ - (cpu) < WORK_CPU_NONE; \ - (cpu) = __next_gcwq_cpu((cpu), cpu_online_mask, 3)) +/** + * for_each_pool_worker - iterate through all workers of a worker_pool + * @worker: iteration cursor + * @wi: integer used for iteration + * @pool: worker_pool to iterate workers of + * + * This must be called with either @pool->manager_mutex or ->lock held. + * + * The if/else clause exists only for the lockdep assertion and can be + * ignored. + */ +#define for_each_pool_worker(worker, wi, pool) \ + idr_for_each_entry(&(pool)->worker_idr, (worker), (wi)) \ + if (({ assert_manager_or_pool_lock((pool)); false; })) { } \ + else -#define for_each_cwq_cpu(cpu, wq) \ - for ((cpu) = __next_wq_cpu(-1, cpu_possible_mask, (wq)); \ - (cpu) < WORK_CPU_NONE; \ - (cpu) = __next_wq_cpu((cpu), cpu_possible_mask, (wq))) +/** + * for_each_pwq - iterate through all pool_workqueues of the specified workqueue + * @pwq: iteration cursor + * @wq: the target workqueue + * + * This must be called either with wq->mutex held or sched RCU read locked. + * If the pwq needs to be used beyond the locking in effect, the caller is + * responsible for guaranteeing that the pwq stays online. + * + * The if/else clause exists only for the lockdep assertion and can be + * ignored. + */ +#define for_each_pwq(pwq, wq) \ + list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node) \ + if (({ assert_rcu_or_wq_mutex(wq); false; })) { } \ + else #ifdef CONFIG_DEBUG_OBJECTS_WORK @@ -453,64 +504,35 @@ static inline void debug_work_activate(struct work_struct *work) { } static inline void debug_work_deactivate(struct work_struct *work) { } #endif -/* Serializes the accesses to the list of workqueues. */ -static DEFINE_SPINLOCK(workqueue_lock); -static LIST_HEAD(workqueues); -static bool workqueue_freezing; /* W: have wqs started freezing? */ - -/* - * The almighty global cpu workqueues. nr_running is the only field - * which is expected to be used frequently by other cpus via - * try_to_wake_up(). Put it in a separate cacheline. - */ -static DEFINE_PER_CPU(struct global_cwq, global_cwq); -static DEFINE_PER_CPU_SHARED_ALIGNED(atomic_t, pool_nr_running[NR_WORKER_POOLS]); - -/* - * Global cpu workqueue and nr_running counter for unbound gcwq. The - * gcwq is always online, has GCWQ_DISASSOCIATED set, and all its - * workers have WORKER_UNBOUND set. - */ -static struct global_cwq unbound_global_cwq; -static atomic_t unbound_pool_nr_running[NR_WORKER_POOLS] = { - [0 ... NR_WORKER_POOLS - 1] = ATOMIC_INIT(0), /* always 0 */ -}; - -static int worker_thread(void *__worker); - -static int worker_pool_pri(struct worker_pool *pool) -{ - return pool - pool->gcwq->pools; -} - -static struct global_cwq *get_gcwq(unsigned int cpu) +/* allocate ID and assign it to @pool */ +static int worker_pool_assign_id(struct worker_pool *pool) { - if (cpu != WORK_CPU_UNBOUND) - return &per_cpu(global_cwq, cpu); - else - return &unbound_global_cwq; -} + int ret; -static atomic_t *get_pool_nr_running(struct worker_pool *pool) -{ - int cpu = pool->gcwq->cpu; - int idx = worker_pool_pri(pool); + lockdep_assert_held(&wq_pool_mutex); - if (cpu != WORK_CPU_UNBOUND) - return &per_cpu(pool_nr_running, cpu)[idx]; - else - return &unbound_pool_nr_running[idx]; + ret = idr_alloc(&worker_pool_idr, pool, 0, 0, GFP_KERNEL); + if (ret >= 0) { + pool->id = ret; + return 0; + } + return ret; } -static struct cpu_workqueue_struct *get_cwq(unsigned int cpu, - struct workqueue_struct *wq) +/** + * unbound_pwq_by_node - return the unbound pool_workqueue for the given node + * @wq: the target workqueue + * @node: the node ID + * + * This must be called either with pwq_lock held or sched RCU read locked. + * If the pwq needs to be used beyond the locking in effect, the caller is + * responsible for guaranteeing that the pwq stays online. + */ +static struct pool_workqueue *unbound_pwq_by_node(struct workqueue_struct *wq, + int node) { - if (!(wq->flags & WQ_UNBOUND)) { - if (likely(cpu < nr_cpu_ids)) - return per_cpu_ptr(wq->cpu_wq.pcpu, cpu); - } else if (likely(cpu == WORK_CPU_UNBOUND)) - return wq->cpu_wq.single; - return NULL; + assert_rcu_or_wq_mutex(wq); + return rcu_dereference_raw(wq->numa_pwq_tbl[node]); } static unsigned int work_color_to_flags(int color) @@ -530,19 +552,19 @@ static int work_next_color(int color) } /* - * While queued, %WORK_STRUCT_CWQ is set and non flag bits of a work's data - * contain the pointer to the queued cwq. Once execution starts, the flag - * is cleared and the high bits contain OFFQ flags and CPU number. + * While queued, %WORK_STRUCT_PWQ is set and non flag bits of a work's data + * contain the pointer to the queued pwq. Once execution starts, the flag + * is cleared and the high bits contain OFFQ flags and pool ID. * - * set_work_cwq(), set_work_cpu_and_clear_pending(), mark_work_canceling() - * and clear_work_data() can be used to set the cwq, cpu or clear + * set_work_pwq(), set_work_pool_and_clear_pending(), mark_work_canceling() + * and clear_work_data() can be used to set the pwq, pool or clear * work->data. These functions should only be called while the work is * owned - ie. while the PENDING bit is set. * - * get_work_[g]cwq() can be used to obtain the gcwq or cwq corresponding to - * a work. gcwq is available once the work has been queued anywhere after - * initialization until it is sync canceled. cwq is available only while - * the work item is queued. + * get_work_pool() and get_work_pwq() can be used to obtain the pool or pwq + * corresponding to a work. Pool is available once the work has been + * queued anywhere after initialization until it is sync canceled. pwq is + * available only while the work item is queued. * * %WORK_OFFQ_CANCELING is used to mark a work item which is being * canceled. While being canceled, a work item may have its PENDING set @@ -552,20 +574,26 @@ static int work_next_color(int color) static inline void set_work_data(struct work_struct *work, unsigned long data, unsigned long flags) { - BUG_ON(!work_pending(work)); + WARN_ON_ONCE(!work_pending(work)); atomic_long_set(&work->data, data | flags | work_static(work)); } -static void set_work_cwq(struct work_struct *work, - struct cpu_workqueue_struct *cwq, +static void set_work_pwq(struct work_struct *work, struct pool_workqueue *pwq, unsigned long extra_flags) { - set_work_data(work, (unsigned long)cwq, - WORK_STRUCT_PENDING | WORK_STRUCT_CWQ | extra_flags); + set_work_data(work, (unsigned long)pwq, + WORK_STRUCT_PENDING | WORK_STRUCT_PWQ | extra_flags); +} + +static void set_work_pool_and_keep_pending(struct work_struct *work, + int pool_id) +{ + set_work_data(work, (unsigned long)pool_id << WORK_OFFQ_POOL_SHIFT, + WORK_STRUCT_PENDING); } -static void set_work_cpu_and_clear_pending(struct work_struct *work, - unsigned int cpu) +static void set_work_pool_and_clear_pending(struct work_struct *work, + int pool_id) { /* * The following wmb is paired with the implied mb in @@ -574,67 +602,100 @@ static void set_work_cpu_and_clear_pending(struct work_struct *work, * owner. */ smp_wmb(); - set_work_data(work, (unsigned long)cpu << WORK_OFFQ_CPU_SHIFT, 0); + set_work_data(work, (unsigned long)pool_id << WORK_OFFQ_POOL_SHIFT, 0); } static void clear_work_data(struct work_struct *work) { - smp_wmb(); /* see set_work_cpu_and_clear_pending() */ - set_work_data(work, WORK_STRUCT_NO_CPU, 0); + smp_wmb(); /* see set_work_pool_and_clear_pending() */ + set_work_data(work, WORK_STRUCT_NO_POOL, 0); } -static struct cpu_workqueue_struct *get_work_cwq(struct work_struct *work) +static struct pool_workqueue *get_work_pwq(struct work_struct *work) { unsigned long data = atomic_long_read(&work->data); - if (data & WORK_STRUCT_CWQ) + if (data & WORK_STRUCT_PWQ) return (void *)(data & WORK_STRUCT_WQ_DATA_MASK); else return NULL; } -static struct global_cwq *get_work_gcwq(struct work_struct *work) +/** + * get_work_pool - return the worker_pool a given work was associated with + * @work: the work item of interest + * + * Return the worker_pool @work was last associated with. %NULL if none. + * + * Pools are created and destroyed under wq_pool_mutex, and allows read + * access under sched-RCU read lock. As such, this function should be + * called under wq_pool_mutex or with preemption disabled. + * + * All fields of the returned pool are accessible as long as the above + * mentioned locking is in effect. If the returned pool needs to be used + * beyond the critical section, the caller is responsible for ensuring the + * returned pool is and stays online. + */ +static struct worker_pool *get_work_pool(struct work_struct *work) { unsigned long data = atomic_long_read(&work->data); - unsigned int cpu; + int pool_id; - if (data & WORK_STRUCT_CWQ) - return ((struct cpu_workqueue_struct *) - (data & WORK_STRUCT_WQ_DATA_MASK))->pool->gcwq; + assert_rcu_or_pool_mutex(); - cpu = data >> WORK_OFFQ_CPU_SHIFT; - if (cpu == WORK_CPU_NONE) + if (data & WORK_STRUCT_PWQ) + return ((struct pool_workqueue *) + (data & WORK_STRUCT_WQ_DATA_MASK))->pool; + + pool_id = data >> WORK_OFFQ_POOL_SHIFT; + if (pool_id == WORK_OFFQ_POOL_NONE) return NULL; - BUG_ON(cpu >= nr_cpu_ids && cpu != WORK_CPU_UNBOUND); - return get_gcwq(cpu); + return idr_find(&worker_pool_idr, pool_id); +} + +/** + * get_work_pool_id - return the worker pool ID a given work is associated with + * @work: the work item of interest + * + * Return the worker_pool ID @work was last associated with. + * %WORK_OFFQ_POOL_NONE if none. + */ +static int get_work_pool_id(struct work_struct *work) +{ + unsigned long data = atomic_long_read(&work->data); + + if (data & WORK_STRUCT_PWQ) + return ((struct pool_workqueue *) + (data & WORK_STRUCT_WQ_DATA_MASK))->pool->id; + + return data >> WORK_OFFQ_POOL_SHIFT; } static void mark_work_canceling(struct work_struct *work) { - struct global_cwq *gcwq = get_work_gcwq(work); - unsigned long cpu = gcwq ? gcwq->cpu : WORK_CPU_NONE; + unsigned long pool_id = get_work_pool_id(work); - set_work_data(work, (cpu << WORK_OFFQ_CPU_SHIFT) | WORK_OFFQ_CANCELING, - WORK_STRUCT_PENDING); + pool_id <<= WORK_OFFQ_POOL_SHIFT; + set_work_data(work, pool_id | WORK_OFFQ_CANCELING, WORK_STRUCT_PENDING); } static bool work_is_canceling(struct work_struct *work) { unsigned long data = atomic_long_read(&work->data); - return !(data & WORK_STRUCT_CWQ) && (data & WORK_OFFQ_CANCELING); + return !(data & WORK_STRUCT_PWQ) && (data & WORK_OFFQ_CANCELING); } /* * Policy functions. These define the policies on how the global worker * pools are managed. Unless noted otherwise, these functions assume that - * they're being called with gcwq->lock held. + * they're being called with pool->lock held. */ static bool __need_more_worker(struct worker_pool *pool) { - return !atomic_read(get_pool_nr_running(pool)); + return !atomic_read(&pool->nr_running); } /* @@ -642,7 +703,7 @@ static bool __need_more_worker(struct worker_pool *pool) * running workers. * * Note that, because unbound workers never contribute to nr_running, this - * function will always return %true for unbound gcwq as long as the + * function will always return %true for unbound pools as long as the * worklist isn't empty. */ static bool need_more_worker(struct worker_pool *pool) @@ -659,9 +720,8 @@ static bool may_start_working(struct worker_pool *pool) /* Do I need to keep working? Called from currently running workers. */ static bool keep_working(struct worker_pool *pool) { - atomic_t *nr_running = get_pool_nr_running(pool); - - return !list_empty(&pool->worklist) && atomic_read(nr_running) <= 1; + return !list_empty(&pool->worklist) && + atomic_read(&pool->nr_running) <= 1; } /* Do we need a new worker? Called from manager. */ @@ -680,7 +740,7 @@ static bool need_to_manage_workers(struct worker_pool *pool) /* Do we have too many workers and should some go away? */ static bool too_many_workers(struct worker_pool *pool) { - bool managing = pool->flags & POOL_MANAGING_WORKERS; + bool managing = mutex_is_locked(&pool->manager_arb); int nr_idle = pool->nr_idle + managing; /* manager is considered idle */ int nr_busy = pool->nr_workers - nr_idle; @@ -714,7 +774,7 @@ static struct worker *first_worker(struct worker_pool *pool) * Wake up the first idle worker of @pool. * * CONTEXT: - * spin_lock_irq(gcwq->lock). + * spin_lock_irq(pool->lock). */ static void wake_up_worker(struct worker_pool *pool) { @@ -735,13 +795,13 @@ static void wake_up_worker(struct worker_pool *pool) * CONTEXT: * spin_lock_irq(rq->lock) */ -void wq_worker_waking_up(struct task_struct *task, unsigned int cpu) +void wq_worker_waking_up(struct task_struct *task, int cpu) { struct worker *worker = kthread_data(task); if (!(worker->flags & WORKER_NOT_RUNNING)) { - WARN_ON_ONCE(worker->pool->gcwq->cpu != cpu); - atomic_inc(get_pool_nr_running(worker->pool)); + WARN_ON_ONCE(worker->pool->cpu != cpu); + atomic_inc(&worker->pool->nr_running); } } @@ -760,18 +820,24 @@ void wq_worker_waking_up(struct task_struct *task, unsigned int cpu) * RETURNS: * Worker task on @cpu to wake up, %NULL if none. */ -struct task_struct *wq_worker_sleeping(struct task_struct *task, - unsigned int cpu) +struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu) { struct worker *worker = kthread_data(task), *to_wakeup = NULL; - struct worker_pool *pool = worker->pool; - atomic_t *nr_running = get_pool_nr_running(pool); + struct worker_pool *pool; + /* + * Rescuers, which may not have all the fields set up like normal + * workers, also reach here, let's not access anything before + * checking NOT_RUNNING. + */ if (worker->flags & WORKER_NOT_RUNNING) return NULL; + pool = worker->pool; + /* this can only happen on the local cpu */ - BUG_ON(cpu != raw_smp_processor_id()); + if (WARN_ON_ONCE(cpu != raw_smp_processor_id())) + return NULL; /* * The counterpart of the following dec_and_test, implied mb, @@ -781,10 +847,11 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task, * NOT_RUNNING is clear. This means that we're bound to and * running on the local cpu w/ rq lock held and preemption * disabled, which in turn means that none else could be - * manipulating idle_list, so dereferencing idle_list without gcwq + * manipulating idle_list, so dereferencing idle_list without pool * lock is safe. */ - if (atomic_dec_and_test(nr_running) && !list_empty(&pool->worklist)) + if (atomic_dec_and_test(&pool->nr_running) && + !list_empty(&pool->worklist)) to_wakeup = first_worker(pool); return to_wakeup ? to_wakeup->task : NULL; } @@ -800,7 +867,7 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task, * woken up. * * CONTEXT: - * spin_lock_irq(gcwq->lock) + * spin_lock_irq(pool->lock) */ static inline void worker_set_flags(struct worker *worker, unsigned int flags, bool wakeup) @@ -816,14 +883,12 @@ static inline void worker_set_flags(struct worker *worker, unsigned int flags, */ if ((flags & WORKER_NOT_RUNNING) && !(worker->flags & WORKER_NOT_RUNNING)) { - atomic_t *nr_running = get_pool_nr_running(pool); - if (wakeup) { - if (atomic_dec_and_test(nr_running) && + if (atomic_dec_and_test(&pool->nr_running) && !list_empty(&pool->worklist)) wake_up_worker(pool); } else - atomic_dec(nr_running); + atomic_dec(&pool->nr_running); } worker->flags |= flags; @@ -837,7 +902,7 @@ static inline void worker_set_flags(struct worker *worker, unsigned int flags, * Clear @flags in @worker->flags and adjust nr_running accordingly. * * CONTEXT: - * spin_lock_irq(gcwq->lock) + * spin_lock_irq(pool->lock) */ static inline void worker_clr_flags(struct worker *worker, unsigned int flags) { @@ -855,87 +920,54 @@ static inline void worker_clr_flags(struct worker *worker, unsigned int flags) */ if ((flags & WORKER_NOT_RUNNING) && (oflags & WORKER_NOT_RUNNING)) if (!(worker->flags & WORKER_NOT_RUNNING)) - atomic_inc(get_pool_nr_running(pool)); + atomic_inc(&pool->nr_running); } /** - * busy_worker_head - return the busy hash head for a work - * @gcwq: gcwq of interest - * @work: work to be hashed - * - * Return hash head of @gcwq for @work. - * - * CONTEXT: - * spin_lock_irq(gcwq->lock). - * - * RETURNS: - * Pointer to the hash head. - */ -static struct hlist_head *busy_worker_head(struct global_cwq *gcwq, - struct work_struct *work) -{ - const int base_shift = ilog2(sizeof(struct work_struct)); - unsigned long v = (unsigned long)work; - - /* simple shift and fold hash, do we need something better? */ - v >>= base_shift; - v += v >> BUSY_WORKER_HASH_ORDER; - v &= BUSY_WORKER_HASH_MASK; - - return &gcwq->busy_hash[v]; -} - -/** - * __find_worker_executing_work - find worker which is executing a work - * @gcwq: gcwq of interest - * @bwh: hash head as returned by busy_worker_head() + * find_worker_executing_work - find worker which is executing a work + * @pool: pool of interest * @work: work to find worker for * - * Find a worker which is executing @work on @gcwq. @bwh should be - * the hash head obtained by calling busy_worker_head() with the same - * work. + * Find a worker which is executing @work on @pool by searching + * @pool->busy_hash which is keyed by the address of @work. For a worker + * to match, its current execution should match the address of @work and + * its work function. This is to avoid unwanted dependency between + * unrelated work executions through a work item being recycled while still + * being executed. + * + * This is a bit tricky. A work item may be freed once its execution + * starts and nothing prevents the freed area from being recycled for + * another work item. If the same work item address ends up being reused + * before the original execution finishes, workqueue will identify the + * recycled work item as currently executing and make it wait until the + * current execution finishes, introducing an unwanted dependency. + * + * This function checks the work item address and work function to avoid + * false positives. Note that this isn't complete as one may construct a + * work function which can introduce dependency onto itself through a + * recycled work item. Well, if somebody wants to shoot oneself in the + * foot that badly, there's only so much we can do, and if such deadlock + * actually occurs, it should be easy to locate the culprit work function. * * CONTEXT: - * spin_lock_irq(gcwq->lock). + * spin_lock_irq(pool->lock). * * RETURNS: * Pointer to worker which is executing @work if found, NULL * otherwise. */ -static struct worker *__find_worker_executing_work(struct global_cwq *gcwq, - struct hlist_head *bwh, - struct work_struct *work) +static struct worker *find_worker_executing_work(struct worker_pool *pool, + struct work_struct *work) { struct worker *worker; - struct hlist_node *tmp; - hlist_for_each_entry(worker, tmp, bwh, hentry) - if (worker->current_work == work) + hash_for_each_possible(pool->busy_hash, worker, hentry, + (unsigned long)work) + if (worker->current_work == work && + worker->current_func == work->func) return worker; - return NULL; -} -/** - * find_worker_executing_work - find worker which is executing a work - * @gcwq: gcwq of interest - * @work: work to find worker for - * - * Find a worker which is executing @work on @gcwq. This function is - * identical to __find_worker_executing_work() except that this - * function calculates @bwh itself. - * - * CONTEXT: - * spin_lock_irq(gcwq->lock). - * - * RETURNS: - * Pointer to worker which is executing @work if found, NULL - * otherwise. - */ -static struct worker *find_worker_executing_work(struct global_cwq *gcwq, - struct work_struct *work) -{ - return __find_worker_executing_work(gcwq, busy_worker_head(gcwq, work), - work); + return NULL; } /** @@ -953,7 +985,7 @@ static struct worker *find_worker_executing_work(struct global_cwq *gcwq, * nested inside outer list_for_each_entry_safe(). * * CONTEXT: - * spin_lock_irq(gcwq->lock). + * spin_lock_irq(pool->lock). */ static void move_linked_works(struct work_struct *work, struct list_head *head, struct work_struct **nextp) @@ -979,67 +1011,127 @@ static void move_linked_works(struct work_struct *work, struct list_head *head, *nextp = n; } -static void cwq_activate_delayed_work(struct work_struct *work) +/** + * get_pwq - get an extra reference on the specified pool_workqueue + * @pwq: pool_workqueue to get + * + * Obtain an extra reference on @pwq. The caller should guarantee that + * @pwq has positive refcnt and be holding the matching pool->lock. + */ +static void get_pwq(struct pool_workqueue *pwq) +{ + lockdep_assert_held(&pwq->pool->lock); + WARN_ON_ONCE(pwq->refcnt <= 0); + pwq->refcnt++; +} + +/** + * put_pwq - put a pool_workqueue reference + * @pwq: pool_workqueue to put + * + * Drop a reference of @pwq. If its refcnt reaches zero, schedule its + * destruction. The caller should be holding the matching pool->lock. + */ +static void put_pwq(struct pool_workqueue *pwq) { - struct cpu_workqueue_struct *cwq = get_work_cwq(work); + lockdep_assert_held(&pwq->pool->lock); + if (likely(--pwq->refcnt)) + return; + if (WARN_ON_ONCE(!(pwq->wq->flags & WQ_UNBOUND))) + return; + /* + * @pwq can't be released under pool->lock, bounce to + * pwq_unbound_release_workfn(). This never recurses on the same + * pool->lock as this path is taken only for unbound workqueues and + * the release work item is scheduled on a per-cpu workqueue. To + * avoid lockdep warning, unbound pool->locks are given lockdep + * subclass of 1 in get_unbound_pool(). + */ + schedule_work(&pwq->unbound_release_work); +} + +/** + * put_pwq_unlocked - put_pwq() with surrounding pool lock/unlock + * @pwq: pool_workqueue to put (can be %NULL) + * + * put_pwq() with locking. This function also allows %NULL @pwq. + */ +static void put_pwq_unlocked(struct pool_workqueue *pwq) +{ + if (pwq) { + /* + * As both pwqs and pools are sched-RCU protected, the + * following lock operations are safe. + */ + spin_lock_irq(&pwq->pool->lock); + put_pwq(pwq); + spin_unlock_irq(&pwq->pool->lock); + } +} + +static void pwq_activate_delayed_work(struct work_struct *work) +{ + struct pool_workqueue *pwq = get_work_pwq(work); trace_workqueue_activate_work(work); - move_linked_works(work, &cwq->pool->worklist, NULL); + move_linked_works(work, &pwq->pool->worklist, NULL); __clear_bit(WORK_STRUCT_DELAYED_BIT, work_data_bits(work)); - cwq->nr_active++; + pwq->nr_active++; } -static void cwq_activate_first_delayed(struct cpu_workqueue_struct *cwq) +static void pwq_activate_first_delayed(struct pool_workqueue *pwq) { - struct work_struct *work = list_first_entry(&cwq->delayed_works, + struct work_struct *work = list_first_entry(&pwq->delayed_works, struct work_struct, entry); - cwq_activate_delayed_work(work); + pwq_activate_delayed_work(work); } /** - * cwq_dec_nr_in_flight - decrement cwq's nr_in_flight - * @cwq: cwq of interest + * pwq_dec_nr_in_flight - decrement pwq's nr_in_flight + * @pwq: pwq of interest * @color: color of work which left the queue * * A work either has completed or is removed from pending queue, - * decrement nr_in_flight of its cwq and handle workqueue flushing. + * decrement nr_in_flight of its pwq and handle workqueue flushing. * * CONTEXT: - * spin_lock_irq(gcwq->lock). + * spin_lock_irq(pool->lock). */ -static void cwq_dec_nr_in_flight(struct cpu_workqueue_struct *cwq, int color) +static void pwq_dec_nr_in_flight(struct pool_workqueue *pwq, int color) { - /* ignore uncolored works */ + /* uncolored work items don't participate in flushing or nr_active */ if (color == WORK_NO_COLOR) - return; + goto out_put; - cwq->nr_in_flight[color]--; + pwq->nr_in_flight[color]--; - cwq->nr_active--; - if (!list_empty(&cwq->delayed_works)) { + pwq->nr_active--; + if (!list_empty(&pwq->delayed_works)) { /* one down, submit a delayed one */ - if (cwq->nr_active < cwq->max_active) - cwq_activate_first_delayed(cwq); + if (pwq->nr_active < pwq->max_active) + pwq_activate_first_delayed(pwq); } /* is flush in progress and are we at the flushing tip? */ - if (likely(cwq->flush_color != color)) - return; + if (likely(pwq->flush_color != color)) + goto out_put; /* are there still in-flight works? */ - if (cwq->nr_in_flight[color]) - return; + if (pwq->nr_in_flight[color]) + goto out_put; - /* this cwq is done, clear flush_color */ - cwq->flush_color = -1; + /* this pwq is done, clear flush_color */ + pwq->flush_color = -1; /* - * If this was the last cwq, wake up the first flusher. It + * If this was the last pwq, wake up the first flusher. It * will handle the rest. */ - if (atomic_dec_and_test(&cwq->wq->nr_cwqs_to_flush)) - complete(&cwq->wq->first_flusher->done); + if (atomic_dec_and_test(&pwq->wq->nr_pwqs_to_flush)) + complete(&pwq->wq->first_flusher->done); +out_put: + put_pwq(pwq); } /** @@ -1070,7 +1162,8 @@ static void cwq_dec_nr_in_flight(struct cpu_workqueue_struct *cwq, int color) static int try_to_grab_pending(struct work_struct *work, bool is_dwork, unsigned long *flags) { - struct global_cwq *gcwq; + struct worker_pool *pool; + struct pool_workqueue *pwq; local_irq_save(*flags); @@ -1095,41 +1188,43 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork, * The queueing is in progress, or it is already queued. Try to * steal it from ->worklist without clearing WORK_STRUCT_PENDING. */ - gcwq = get_work_gcwq(work); - if (!gcwq) + pool = get_work_pool(work); + if (!pool) goto fail; - spin_lock(&gcwq->lock); - if (!list_empty(&work->entry)) { + spin_lock(&pool->lock); + /* + * work->data is guaranteed to point to pwq only while the work + * item is queued on pwq->wq, and both updating work->data to point + * to pwq on queueing and to pool on dequeueing are done under + * pwq->pool->lock. This in turn guarantees that, if work->data + * points to pwq which is associated with a locked pool, the work + * item is currently queued on that pool. + */ + pwq = get_work_pwq(work); + if (pwq && pwq->pool == pool) { + debug_work_deactivate(work); + /* - * This work is queued, but perhaps we locked the wrong gcwq. - * In that case we must see the new value after rmb(), see - * insert_work()->wmb(). + * A delayed work item cannot be grabbed directly because + * it might have linked NO_COLOR work items which, if left + * on the delayed_list, will confuse pwq->nr_active + * management later on and cause stall. Make sure the work + * item is activated before grabbing. */ - smp_rmb(); - if (gcwq == get_work_gcwq(work)) { - debug_work_deactivate(work); + if (*work_data_bits(work) & WORK_STRUCT_DELAYED) + pwq_activate_delayed_work(work); - /* - * A delayed work item cannot be grabbed directly - * because it might have linked NO_COLOR work items - * which, if left on the delayed_list, will confuse - * cwq->nr_active management later on and cause - * stall. Make sure the work item is activated - * before grabbing. - */ - if (*work_data_bits(work) & WORK_STRUCT_DELAYED) - cwq_activate_delayed_work(work); + list_del_init(&work->entry); + pwq_dec_nr_in_flight(get_work_pwq(work), get_work_color(work)); - list_del_init(&work->entry); - cwq_dec_nr_in_flight(get_work_cwq(work), - get_work_color(work)); + /* work->data points to pwq iff queued, point to pool */ + set_work_pool_and_keep_pending(work, pool->id); - spin_unlock(&gcwq->lock); - return 1; - } + spin_unlock(&pool->lock); + return 1; } - spin_unlock(&gcwq->lock); + spin_unlock(&pool->lock); fail: local_irq_restore(*flags); if (work_is_canceling(work)) @@ -1139,39 +1234,32 @@ fail: } /** - * insert_work - insert a work into gcwq - * @cwq: cwq @work belongs to + * insert_work - insert a work into a pool + * @pwq: pwq @work belongs to * @work: work to insert * @head: insertion point * @extra_flags: extra WORK_STRUCT_* flags to set * - * Insert @work which belongs to @cwq into @gcwq after @head. - * @extra_flags is or'd to work_struct flags. + * Insert @work which belongs to @pwq after @head. @extra_flags is or'd to + * work_struct flags. * * CONTEXT: - * spin_lock_irq(gcwq->lock). + * spin_lock_irq(pool->lock). */ -static void insert_work(struct cpu_workqueue_struct *cwq, - struct work_struct *work, struct list_head *head, - unsigned int extra_flags) +static void insert_work(struct pool_workqueue *pwq, struct work_struct *work, + struct list_head *head, unsigned int extra_flags) { - struct worker_pool *pool = cwq->pool; + struct worker_pool *pool = pwq->pool; /* we own @work, set data and link */ - set_work_cwq(work, cwq, extra_flags); - - /* - * Ensure that we get the right work->data if we see the - * result of list_add() below, see try_to_grab_pending(). - */ - smp_wmb(); - + set_work_pwq(work, pwq, extra_flags); list_add_tail(&work->entry, head); + get_pwq(pwq); /* - * Ensure either worker_sched_deactivated() sees the above - * list_add_tail() or we see zero nr_running to avoid workers - * lying around lazily while there are works to be processed. + * Ensure either wq_worker_sleeping() sees the above + * list_add_tail() or we see zero nr_running to avoid workers lying + * around lazily while there are works to be processed. */ smp_mb(); @@ -1181,41 +1269,25 @@ static void insert_work(struct cpu_workqueue_struct *cwq, /* * Test whether @work is being queued from another work executing on the - * same workqueue. This is rather expensive and should only be used from - * cold paths. + * same workqueue. */ static bool is_chained_work(struct workqueue_struct *wq) { - unsigned long flags; - unsigned int cpu; - - for_each_gcwq_cpu(cpu) { - struct global_cwq *gcwq = get_gcwq(cpu); - struct worker *worker; - struct hlist_node *pos; - int i; + struct worker *worker; - spin_lock_irqsave(&gcwq->lock, flags); - for_each_busy_worker(worker, i, pos, gcwq) { - if (worker->task != current) - continue; - spin_unlock_irqrestore(&gcwq->lock, flags); - /* - * I'm @worker, no locking necessary. See if @work - * is headed to the same workqueue. - */ - return worker->current_cwq->wq == wq; - } - spin_unlock_irqrestore(&gcwq->lock, flags); - } - return false; + worker = current_wq_worker(); + /* + * Return %true iff I'm a worker execuing a work item on @wq. If + * I'm @worker, it's safe to dereference it without locking. + */ + return worker && worker->current_pwq->wq == wq; } -static void __queue_work(unsigned int cpu, struct workqueue_struct *wq, +static void __queue_work(int cpu, struct workqueue_struct *wq, struct work_struct *work) { - struct global_cwq *gcwq; - struct cpu_workqueue_struct *cwq; + struct pool_workqueue *pwq; + struct worker_pool *last_pool; struct list_head *worklist; unsigned int work_flags; unsigned int req_cpu = cpu; @@ -1231,72 +1303,85 @@ static void __queue_work(unsigned int cpu, struct workqueue_struct *wq, debug_work_activate(work); /* if dying, only works from the same workqueue are allowed */ - if (unlikely(wq->flags & WQ_DRAINING) && + if (unlikely(wq->flags & __WQ_DRAINING) && WARN_ON_ONCE(!is_chained_work(wq))) return; +retry: + if (req_cpu == WORK_CPU_UNBOUND) + cpu = raw_smp_processor_id(); - /* determine gcwq to use */ - if (!(wq->flags & WQ_UNBOUND)) { - struct global_cwq *last_gcwq; - - if (cpu == WORK_CPU_UNBOUND) - cpu = raw_smp_processor_id(); - - /* - * It's multi cpu. If @work was previously on a different - * cpu, it might still be running there, in which case the - * work needs to be queued on that cpu to guarantee - * non-reentrancy. - */ - gcwq = get_gcwq(cpu); - last_gcwq = get_work_gcwq(work); + /* pwq which will be used unless @work is executing elsewhere */ + if (!(wq->flags & WQ_UNBOUND)) + pwq = per_cpu_ptr(wq->cpu_pwqs, cpu); + else + pwq = unbound_pwq_by_node(wq, cpu_to_node(cpu)); - if (last_gcwq && last_gcwq != gcwq) { - struct worker *worker; + /* + * If @work was previously on a different pool, it might still be + * running there, in which case the work needs to be queued on that + * pool to guarantee non-reentrancy. + */ + last_pool = get_work_pool(work); + if (last_pool && last_pool != pwq->pool) { + struct worker *worker; - spin_lock(&last_gcwq->lock); + spin_lock(&last_pool->lock); - worker = find_worker_executing_work(last_gcwq, work); + worker = find_worker_executing_work(last_pool, work); - if (worker && worker->current_cwq->wq == wq) - gcwq = last_gcwq; - else { - /* meh... not running there, queue here */ - spin_unlock(&last_gcwq->lock); - spin_lock(&gcwq->lock); - } + if (worker && worker->current_pwq->wq == wq) { + pwq = worker->current_pwq; } else { - spin_lock(&gcwq->lock); + /* meh... not running there, queue here */ + spin_unlock(&last_pool->lock); + spin_lock(&pwq->pool->lock); } } else { - gcwq = get_gcwq(WORK_CPU_UNBOUND); - spin_lock(&gcwq->lock); + spin_lock(&pwq->pool->lock); + } + + /* + * pwq is determined and locked. For unbound pools, we could have + * raced with pwq release and it could already be dead. If its + * refcnt is zero, repeat pwq selection. Note that pwqs never die + * without another pwq replacing it in the numa_pwq_tbl or while + * work items are executing on it, so the retrying is guaranteed to + * make forward-progress. + */ + if (unlikely(!pwq->refcnt)) { + if (wq->flags & WQ_UNBOUND) { + spin_unlock(&pwq->pool->lock); + cpu_relax(); + goto retry; + } + /* oops */ + WARN_ONCE(true, "workqueue: per-cpu pwq for %s on cpu%d has 0 refcnt", + wq->name, cpu); } - /* gcwq determined, get cwq and queue */ - cwq = get_cwq(gcwq->cpu, wq); - trace_workqueue_queue_work(req_cpu, cwq, work); + /* pwq determined, queue */ + trace_workqueue_queue_work(req_cpu, pwq, work); if (WARN_ON(!list_empty(&work->entry))) { - spin_unlock(&gcwq->lock); + spin_unlock(&pwq->pool->lock); return; } - cwq->nr_in_flight[cwq->work_color]++; - work_flags = work_color_to_flags(cwq->work_color); + pwq->nr_in_flight[pwq->work_color]++; + work_flags = work_color_to_flags(pwq->work_color); - if (likely(cwq->nr_active < cwq->max_active)) { + if (likely(pwq->nr_active < pwq->max_active)) { trace_workqueue_activate_work(work); - cwq->nr_active++; - worklist = &cwq->pool->worklist; + pwq->nr_active++; + worklist = &pwq->pool->worklist; } else { work_flags |= WORK_STRUCT_DELAYED; - worklist = &cwq->delayed_works; + worklist = &pwq->delayed_works; } - insert_work(cwq, work, worklist, work_flags); + insert_work(pwq, work, worklist, work_flags); - spin_unlock(&gcwq->lock); + spin_unlock(&pwq->pool->lock); } /** @@ -1328,38 +1413,20 @@ bool queue_work_on(int cpu, struct workqueue_struct *wq, } EXPORT_SYMBOL_GPL(queue_work_on); -/** - * queue_work - queue work on a workqueue - * @wq: workqueue to use - * @work: work to queue - * - * Returns %false if @work was already on a queue, %true otherwise. - * - * We queue the work to the CPU on which it was submitted, but if the CPU dies - * it can be processed by another CPU. - */ -bool queue_work(struct workqueue_struct *wq, struct work_struct *work) -{ - return queue_work_on(WORK_CPU_UNBOUND, wq, work); -} -EXPORT_SYMBOL_GPL(queue_work); - void delayed_work_timer_fn(unsigned long __data) { struct delayed_work *dwork = (struct delayed_work *)__data; - struct cpu_workqueue_struct *cwq = get_work_cwq(&dwork->work); /* should have been called from irqsafe timer with irq already off */ - __queue_work(dwork->cpu, cwq->wq, &dwork->work); + __queue_work(dwork->cpu, dwork->wq, &dwork->work); } -EXPORT_SYMBOL_GPL(delayed_work_timer_fn); +EXPORT_SYMBOL(delayed_work_timer_fn); static void __queue_delayed_work(int cpu, struct workqueue_struct *wq, struct delayed_work *dwork, unsigned long delay) { struct timer_list *timer = &dwork->timer; struct work_struct *work = &dwork->work; - unsigned int lcpu; WARN_ON_ONCE(timer->function != delayed_work_timer_fn || timer->data != (unsigned long)dwork); @@ -1379,30 +1446,7 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq, timer_stats_timer_set_start_info(&dwork->timer); - /* - * This stores cwq for the moment, for the timer_fn. Note that the - * work's gcwq is preserved to allow reentrance detection for - * delayed works. - */ - if (!(wq->flags & WQ_UNBOUND)) { - struct global_cwq *gcwq = get_work_gcwq(work); - - /* - * If we cannot get the last gcwq from @work directly, - * select the last CPU such that it avoids unnecessarily - * triggering non-reentrancy check in __queue_work(). - */ - lcpu = cpu; - if (gcwq) - lcpu = gcwq->cpu; - if (lcpu == WORK_CPU_UNBOUND) - lcpu = raw_smp_processor_id(); - } else { - lcpu = WORK_CPU_UNBOUND; - } - - set_work_cwq(work, get_cwq(lcpu, wq), 0); - + dwork->wq = wq; dwork->cpu = cpu; timer->expires = jiffies + delay; @@ -1444,21 +1488,6 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq, EXPORT_SYMBOL_GPL(queue_delayed_work_on); /** - * queue_delayed_work - queue work on a workqueue after delay - * @wq: workqueue to use - * @dwork: delayable work to queue - * @delay: number of jiffies to wait before queueing - * - * Equivalent to queue_delayed_work_on() but tries to use the local CPU. - */ -bool queue_delayed_work(struct workqueue_struct *wq, - struct delayed_work *dwork, unsigned long delay) -{ - return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay); -} -EXPORT_SYMBOL_GPL(queue_delayed_work); - -/** * mod_delayed_work_on - modify delay of or queue a delayed work on specific CPU * @cpu: CPU number to execute work on * @wq: workqueue to use @@ -1497,21 +1526,6 @@ bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq, EXPORT_SYMBOL_GPL(mod_delayed_work_on); /** - * mod_delayed_work - modify delay of or queue a delayed work - * @wq: workqueue to use - * @dwork: work to queue - * @delay: number of jiffies to wait before queueing - * - * mod_delayed_work_on() on local CPU. - */ -bool mod_delayed_work(struct workqueue_struct *wq, struct delayed_work *dwork, - unsigned long delay) -{ - return mod_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay); -} -EXPORT_SYMBOL_GPL(mod_delayed_work); - -/** * worker_enter_idle - enter idle state * @worker: worker which is entering idle state * @@ -1519,16 +1533,16 @@ EXPORT_SYMBOL_GPL(mod_delayed_work); * necessary. * * LOCKING: - * spin_lock_irq(gcwq->lock). + * spin_lock_irq(pool->lock). */ static void worker_enter_idle(struct worker *worker) { struct worker_pool *pool = worker->pool; - struct global_cwq *gcwq = pool->gcwq; - BUG_ON(worker->flags & WORKER_IDLE); - BUG_ON(!list_empty(&worker->entry) && - (worker->hentry.next || worker->hentry.pprev)); + if (WARN_ON_ONCE(worker->flags & WORKER_IDLE) || + WARN_ON_ONCE(!list_empty(&worker->entry) && + (worker->hentry.next || worker->hentry.pprev))) + return; /* can't use worker_set_flags(), also called from start_worker() */ worker->flags |= WORKER_IDLE; @@ -1542,14 +1556,14 @@ static void worker_enter_idle(struct worker *worker) mod_timer(&pool->idle_timer, jiffies + IDLE_WORKER_TIMEOUT); /* - * Sanity check nr_running. Because gcwq_unbind_fn() releases - * gcwq->lock between setting %WORKER_UNBOUND and zapping + * Sanity check nr_running. Because wq_unbind_fn() releases + * pool->lock between setting %WORKER_UNBOUND and zapping * nr_running, the warning may trigger spuriously. Check iff * unbind is not in progress. */ - WARN_ON_ONCE(!(gcwq->flags & GCWQ_DISASSOCIATED) && + WARN_ON_ONCE(!(pool->flags & POOL_DISASSOCIATED) && pool->nr_workers == pool->nr_idle && - atomic_read(get_pool_nr_running(pool))); + atomic_read(&pool->nr_running)); } /** @@ -1559,72 +1573,71 @@ static void worker_enter_idle(struct worker *worker) * @worker is leaving idle state. Update stats. * * LOCKING: - * spin_lock_irq(gcwq->lock). + * spin_lock_irq(pool->lock). */ static void worker_leave_idle(struct worker *worker) { struct worker_pool *pool = worker->pool; - BUG_ON(!(worker->flags & WORKER_IDLE)); + if (WARN_ON_ONCE(!(worker->flags & WORKER_IDLE))) + return; worker_clr_flags(worker, WORKER_IDLE); pool->nr_idle--; list_del_init(&worker->entry); } /** - * worker_maybe_bind_and_lock - bind worker to its cpu if possible and lock gcwq - * @worker: self + * worker_maybe_bind_and_lock - try to bind %current to worker_pool and lock it + * @pool: target worker_pool + * + * Bind %current to the cpu of @pool if it is associated and lock @pool. * * Works which are scheduled while the cpu is online must at least be * scheduled to a worker which is bound to the cpu so that if they are * flushed from cpu callbacks while cpu is going down, they are * guaranteed to execute on the cpu. * - * This function is to be used by rogue workers and rescuers to bind + * This function is to be used by unbound workers and rescuers to bind * themselves to the target cpu and may race with cpu going down or * coming online. kthread_bind() can't be used because it may put the * worker to already dead cpu and set_cpus_allowed_ptr() can't be used - * verbatim as it's best effort and blocking and gcwq may be + * verbatim as it's best effort and blocking and pool may be * [dis]associated in the meantime. * - * This function tries set_cpus_allowed() and locks gcwq and verifies the - * binding against %GCWQ_DISASSOCIATED which is set during + * This function tries set_cpus_allowed() and locks pool and verifies the + * binding against %POOL_DISASSOCIATED which is set during * %CPU_DOWN_PREPARE and cleared during %CPU_ONLINE, so if the worker * enters idle state or fetches works without dropping lock, it can * guarantee the scheduling requirement described in the first paragraph. * * CONTEXT: - * Might sleep. Called without any lock but returns with gcwq->lock + * Might sleep. Called without any lock but returns with pool->lock * held. * * RETURNS: - * %true if the associated gcwq is online (@worker is successfully + * %true if the associated pool is online (@worker is successfully * bound), %false if offline. */ -static bool worker_maybe_bind_and_lock(struct worker *worker) -__acquires(&gcwq->lock) +static bool worker_maybe_bind_and_lock(struct worker_pool *pool) +__acquires(&pool->lock) { - struct global_cwq *gcwq = worker->pool->gcwq; - struct task_struct *task = worker->task; - while (true) { /* * The following call may fail, succeed or succeed * without actually migrating the task to the cpu if * it races with cpu hotunplug operation. Verify - * against GCWQ_DISASSOCIATED. + * against POOL_DISASSOCIATED. */ - if (!(gcwq->flags & GCWQ_DISASSOCIATED)) - set_cpus_allowed_ptr(task, get_cpu_mask(gcwq->cpu)); + if (!(pool->flags & POOL_DISASSOCIATED)) + set_cpus_allowed_ptr(current, pool->attrs->cpumask); - spin_lock_irq(&gcwq->lock); - if (gcwq->flags & GCWQ_DISASSOCIATED) + spin_lock_irq(&pool->lock); + if (pool->flags & POOL_DISASSOCIATED) return false; - if (task_cpu(task) == gcwq->cpu && - cpumask_equal(¤t->cpus_allowed, - get_cpu_mask(gcwq->cpu))) + if (task_cpu(current) == pool->cpu && + cpumask_equal(¤t->cpus_allowed, pool->attrs->cpumask)) return true; - spin_unlock_irq(&gcwq->lock); + spin_unlock_irq(&pool->lock); /* * We've raced with CPU hot[un]plug. Give it a breather @@ -1637,118 +1650,6 @@ __acquires(&gcwq->lock) } } -/* - * Rebind an idle @worker to its CPU. worker_thread() will test - * list_empty(@worker->entry) before leaving idle and call this function. - */ -static void idle_worker_rebind(struct worker *worker) -{ - struct global_cwq *gcwq = worker->pool->gcwq; - - /* CPU may go down again inbetween, clear UNBOUND only on success */ - if (worker_maybe_bind_and_lock(worker)) - worker_clr_flags(worker, WORKER_UNBOUND); - - /* rebind complete, become available again */ - list_add(&worker->entry, &worker->pool->idle_list); - spin_unlock_irq(&gcwq->lock); -} - -/* - * Function for @worker->rebind.work used to rebind unbound busy workers to - * the associated cpu which is coming back online. This is scheduled by - * cpu up but can race with other cpu hotplug operations and may be - * executed twice without intervening cpu down. - */ -static void busy_worker_rebind_fn(struct work_struct *work) -{ - struct worker *worker = container_of(work, struct worker, rebind_work); - struct global_cwq *gcwq = worker->pool->gcwq; - - if (worker_maybe_bind_and_lock(worker)) - worker_clr_flags(worker, WORKER_UNBOUND); - - spin_unlock_irq(&gcwq->lock); -} - -/** - * rebind_workers - rebind all workers of a gcwq to the associated CPU - * @gcwq: gcwq of interest - * - * @gcwq->cpu is coming online. Rebind all workers to the CPU. Rebinding - * is different for idle and busy ones. - * - * Idle ones will be removed from the idle_list and woken up. They will - * add themselves back after completing rebind. This ensures that the - * idle_list doesn't contain any unbound workers when re-bound busy workers - * try to perform local wake-ups for concurrency management. - * - * Busy workers can rebind after they finish their current work items. - * Queueing the rebind work item at the head of the scheduled list is - * enough. Note that nr_running will be properly bumped as busy workers - * rebind. - * - * On return, all non-manager workers are scheduled for rebind - see - * manage_workers() for the manager special case. Any idle worker - * including the manager will not appear on @idle_list until rebind is - * complete, making local wake-ups safe. - */ -static void rebind_workers(struct global_cwq *gcwq) -{ - struct worker_pool *pool; - struct worker *worker, *n; - struct hlist_node *pos; - int i; - - lockdep_assert_held(&gcwq->lock); - - for_each_worker_pool(pool, gcwq) - lockdep_assert_held(&pool->assoc_mutex); - - /* dequeue and kick idle ones */ - for_each_worker_pool(pool, gcwq) { - list_for_each_entry_safe(worker, n, &pool->idle_list, entry) { - /* - * idle workers should be off @pool->idle_list - * until rebind is complete to avoid receiving - * premature local wake-ups. - */ - list_del_init(&worker->entry); - - /* - * worker_thread() will see the above dequeuing - * and call idle_worker_rebind(). - */ - wake_up_process(worker->task); - } - } - - /* rebind busy workers */ - for_each_busy_worker(worker, i, pos, gcwq) { - struct work_struct *rebind_work = &worker->rebind_work; - struct workqueue_struct *wq; - - if (test_and_set_bit(WORK_STRUCT_PENDING_BIT, - work_data_bits(rebind_work))) - continue; - - debug_work_activate(rebind_work); - - /* - * wq doesn't really matter but let's keep @worker->pool - * and @cwq->pool consistent for sanity. - */ - if (worker_pool_pri(worker->pool)) - wq = system_highpri_wq; - else - wq = system_wq; - - insert_work(get_cwq(gcwq->cpu, wq), rebind_work, - worker->scheduled.next, - work_color_to_flags(WORK_NO_COLOR)); - } -} - static struct worker *alloc_worker(void) { struct worker *worker; @@ -1757,7 +1658,6 @@ static struct worker *alloc_worker(void) if (worker) { INIT_LIST_HEAD(&worker->entry); INIT_LIST_HEAD(&worker->scheduled); - INIT_WORK(&worker->rebind_work, busy_worker_rebind_fn); /* on creation a worker is in !idle && prep state */ worker->flags = WORKER_PREP; } @@ -1780,19 +1680,25 @@ static struct worker *alloc_worker(void) */ static struct worker *create_worker(struct worker_pool *pool) { - struct global_cwq *gcwq = pool->gcwq; - const char *pri = worker_pool_pri(pool) ? "H" : ""; struct worker *worker = NULL; int id = -1; + char id_buf[16]; - spin_lock_irq(&gcwq->lock); - while (ida_get_new(&pool->worker_ida, &id)) { - spin_unlock_irq(&gcwq->lock); - if (!ida_pre_get(&pool->worker_ida, GFP_KERNEL)) - goto fail; - spin_lock_irq(&gcwq->lock); - } - spin_unlock_irq(&gcwq->lock); + lockdep_assert_held(&pool->manager_mutex); + + /* + * ID is needed to determine kthread name. Allocate ID first + * without installing the pointer. + */ + idr_preload(GFP_KERNEL); + spin_lock_irq(&pool->lock); + + id = idr_alloc(&pool->worker_idr, NULL, 0, 0, GFP_NOWAIT); + + spin_unlock_irq(&pool->lock); + idr_preload_end(); + if (id < 0) + goto fail; worker = alloc_worker(); if (!worker) @@ -1801,41 +1707,47 @@ static struct worker *create_worker(struct worker_pool *pool) worker->pool = pool; worker->id = id; - if (gcwq->cpu != WORK_CPU_UNBOUND) - worker->task = kthread_create_on_node(worker_thread, - worker, cpu_to_node(gcwq->cpu), - "kworker/%u:%d%s", gcwq->cpu, id, pri); + if (pool->cpu >= 0) + snprintf(id_buf, sizeof(id_buf), "%d:%d%s", pool->cpu, id, + pool->attrs->nice < 0 ? "H" : ""); else - worker->task = kthread_create(worker_thread, worker, - "kworker/u:%d%s", id, pri); + snprintf(id_buf, sizeof(id_buf), "u%d:%d", pool->id, id); + + worker->task = kthread_create_on_node(worker_thread, worker, pool->node, + "kworker/%s", id_buf); if (IS_ERR(worker->task)) goto fail; - if (worker_pool_pri(pool)) - set_user_nice(worker->task, HIGHPRI_NICE_LEVEL); + /* + * set_cpus_allowed_ptr() will fail if the cpumask doesn't have any + * online CPUs. It'll be re-applied when any of the CPUs come up. + */ + set_user_nice(worker->task, pool->attrs->nice); + set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask); + + /* prevent userland from meddling with cpumask of workqueue workers */ + worker->task->flags |= PF_NO_SETAFFINITY; /* - * Determine CPU binding of the new worker depending on - * %GCWQ_DISASSOCIATED. The caller is responsible for ensuring the - * flag remains stable across this function. See the comments - * above the flag definition for details. - * - * As an unbound worker may later become a regular one if CPU comes - * online, make sure every worker has %PF_THREAD_BOUND set. + * The caller is responsible for ensuring %POOL_DISASSOCIATED + * remains stable across this function. See the comments above the + * flag definition for details. */ - if (!(gcwq->flags & GCWQ_DISASSOCIATED)) { - kthread_bind(worker->task, gcwq->cpu); - } else { - worker->task->flags |= PF_THREAD_BOUND; + if (pool->flags & POOL_DISASSOCIATED) worker->flags |= WORKER_UNBOUND; - } + + /* successful, commit the pointer to idr */ + spin_lock_irq(&pool->lock); + idr_replace(&pool->worker_idr, worker, worker->id); + spin_unlock_irq(&pool->lock); return worker; + fail: if (id >= 0) { - spin_lock_irq(&gcwq->lock); - ida_remove(&pool->worker_ida, id); - spin_unlock_irq(&gcwq->lock); + spin_lock_irq(&pool->lock); + idr_remove(&pool->worker_idr, id); + spin_unlock_irq(&pool->lock); } kfree(worker); return NULL; @@ -1845,10 +1757,10 @@ fail: * start_worker - start a newly created worker * @worker: worker to start * - * Make the gcwq aware of @worker and start it. + * Make the pool aware of @worker and start it. * * CONTEXT: - * spin_lock_irq(gcwq->lock). + * spin_lock_irq(pool->lock). */ static void start_worker(struct worker *worker) { @@ -1859,23 +1771,49 @@ static void start_worker(struct worker *worker) } /** + * create_and_start_worker - create and start a worker for a pool + * @pool: the target pool + * + * Grab the managership of @pool and create and start a new worker for it. + */ +static int create_and_start_worker(struct worker_pool *pool) +{ + struct worker *worker; + + mutex_lock(&pool->manager_mutex); + + worker = create_worker(pool); + if (worker) { + spin_lock_irq(&pool->lock); + start_worker(worker); + spin_unlock_irq(&pool->lock); + } + + mutex_unlock(&pool->manager_mutex); + + return worker ? 0 : -ENOMEM; +} + +/** * destroy_worker - destroy a workqueue worker * @worker: worker to be destroyed * - * Destroy @worker and adjust @gcwq stats accordingly. + * Destroy @worker and adjust @pool stats accordingly. * * CONTEXT: - * spin_lock_irq(gcwq->lock) which is released and regrabbed. + * spin_lock_irq(pool->lock) which is released and regrabbed. */ static void destroy_worker(struct worker *worker) { struct worker_pool *pool = worker->pool; - struct global_cwq *gcwq = pool->gcwq; - int id = worker->id; + + lockdep_assert_held(&pool->manager_mutex); + lockdep_assert_held(&pool->lock); /* sanity check frenzy */ - BUG_ON(worker->current_work); - BUG_ON(!list_empty(&worker->scheduled)); + if (WARN_ON(worker->current_work) || + WARN_ON(!list_empty(&worker->scheduled))) + return; if (worker->flags & WORKER_STARTED) pool->nr_workers--; @@ -1885,21 +1823,21 @@ static void destroy_worker(struct worker *worker) list_del_init(&worker->entry); worker->flags |= WORKER_DIE; - spin_unlock_irq(&gcwq->lock); + idr_remove(&pool->worker_idr, worker->id); + + spin_unlock_irq(&pool->lock); kthread_stop(worker->task); kfree(worker); - spin_lock_irq(&gcwq->lock); - ida_remove(&pool->worker_ida, id); + spin_lock_irq(&pool->lock); } static void idle_worker_timeout(unsigned long __pool) { struct worker_pool *pool = (void *)__pool; - struct global_cwq *gcwq = pool->gcwq; - spin_lock_irq(&gcwq->lock); + spin_lock_irq(&pool->lock); if (too_many_workers(pool)) { struct worker *worker; @@ -1918,35 +1856,33 @@ static void idle_worker_timeout(unsigned long __pool) } } - spin_unlock_irq(&gcwq->lock); + spin_unlock_irq(&pool->lock); } -static bool send_mayday(struct work_struct *work) +static void send_mayday(struct work_struct *work) { - struct cpu_workqueue_struct *cwq = get_work_cwq(work); - struct workqueue_struct *wq = cwq->wq; - unsigned int cpu; + struct pool_workqueue *pwq = get_work_pwq(work); + struct workqueue_struct *wq = pwq->wq; - if (!(wq->flags & WQ_RESCUER)) - return false; + lockdep_assert_held(&wq_mayday_lock); + + if (!wq->rescuer) + return; /* mayday mayday mayday */ - cpu = cwq->pool->gcwq->cpu; - /* WORK_CPU_UNBOUND can't be set in cpumask, use cpu 0 instead */ - if (cpu == WORK_CPU_UNBOUND) - cpu = 0; - if (!mayday_test_and_set_cpu(cpu, wq->mayday_mask)) + if (list_empty(&pwq->mayday_node)) { + list_add_tail(&pwq->mayday_node, &wq->maydays); wake_up_process(wq->rescuer->task); - return true; + } } -static void gcwq_mayday_timeout(unsigned long __pool) +static void pool_mayday_timeout(unsigned long __pool) { struct worker_pool *pool = (void *)__pool; - struct global_cwq *gcwq = pool->gcwq; struct work_struct *work; - spin_lock_irq(&gcwq->lock); + spin_lock_irq(&wq_mayday_lock); /* for wq->maydays */ + spin_lock(&pool->lock); if (need_to_create_worker(pool)) { /* @@ -1959,7 +1895,8 @@ static void gcwq_mayday_timeout(unsigned long __pool) send_mayday(work); } - spin_unlock_irq(&gcwq->lock); + spin_unlock(&pool->lock); + spin_unlock_irq(&wq_mayday_lock); mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INTERVAL); } @@ -1974,28 +1911,26 @@ static void gcwq_mayday_timeout(unsigned long __pool) * sent to all rescuers with works scheduled on @pool to resolve * possible allocation deadlock. * - * On return, need_to_create_worker() is guaranteed to be false and - * may_start_working() true. + * On return, need_to_create_worker() is guaranteed to be %false and + * may_start_working() %true. * * LOCKING: - * spin_lock_irq(gcwq->lock) which may be released and regrabbed + * spin_lock_irq(pool->lock) which may be released and regrabbed * multiple times. Does GFP_KERNEL allocations. Called only from * manager. * * RETURNS: - * false if no action was taken and gcwq->lock stayed locked, true + * %false if no action was taken and pool->lock stayed locked, %true * otherwise. */ static bool maybe_create_worker(struct worker_pool *pool) -__releases(&gcwq->lock) -__acquires(&gcwq->lock) +__releases(&pool->lock) +__acquires(&pool->lock) { - struct global_cwq *gcwq = pool->gcwq; - if (!need_to_create_worker(pool)) return false; restart: - spin_unlock_irq(&gcwq->lock); + spin_unlock_irq(&pool->lock); /* if we don't make progress in MAYDAY_INITIAL_TIMEOUT, call for help */ mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INITIAL_TIMEOUT); @@ -2006,9 +1941,10 @@ restart: worker = create_worker(pool); if (worker) { del_timer_sync(&pool->mayday_timer); - spin_lock_irq(&gcwq->lock); + spin_lock_irq(&pool->lock); start_worker(worker); - BUG_ON(need_to_create_worker(pool)); + if (WARN_ON_ONCE(need_to_create_worker(pool))) + goto restart; return true; } @@ -2023,7 +1959,7 @@ restart: } del_timer_sync(&pool->mayday_timer); - spin_lock_irq(&gcwq->lock); + spin_lock_irq(&pool->lock); if (need_to_create_worker(pool)) goto restart; return true; @@ -2037,11 +1973,11 @@ restart: * IDLE_WORKER_TIMEOUT. * * LOCKING: - * spin_lock_irq(gcwq->lock) which may be released and regrabbed + * spin_lock_irq(pool->lock) which may be released and regrabbed * multiple times. Called only from manager. * * RETURNS: - * false if no action was taken and gcwq->lock stayed locked, true + * %false if no action was taken and pool->lock stayed locked, %true * otherwise. */ static bool maybe_destroy_workers(struct worker_pool *pool) @@ -2071,63 +2007,58 @@ static bool maybe_destroy_workers(struct worker_pool *pool) * manage_workers - manage worker pool * @worker: self * - * Assume the manager role and manage gcwq worker pool @worker belongs + * Assume the manager role and manage the worker pool @worker belongs * to. At any given time, there can be only zero or one manager per - * gcwq. The exclusion is handled automatically by this function. + * pool. The exclusion is handled automatically by this function. * * The caller can safely start processing works on false return. On * true return, it's guaranteed that need_to_create_worker() is false * and may_start_working() is true. * * CONTEXT: - * spin_lock_irq(gcwq->lock) which may be released and regrabbed + * spin_lock_irq(pool->lock) which may be released and regrabbed * multiple times. Does GFP_KERNEL allocations. * * RETURNS: - * false if no action was taken and gcwq->lock stayed locked, true if - * some action was taken. + * spin_lock_irq(pool->lock) which may be released and regrabbed + * multiple times. Does GFP_KERNEL allocations. */ static bool manage_workers(struct worker *worker) { struct worker_pool *pool = worker->pool; bool ret = false; - if (pool->flags & POOL_MANAGING_WORKERS) - return ret; - - pool->flags |= POOL_MANAGING_WORKERS; - /* - * To simplify both worker management and CPU hotplug, hold off - * management while hotplug is in progress. CPU hotplug path can't - * grab %POOL_MANAGING_WORKERS to achieve this because that can - * lead to idle worker depletion (all become busy thinking someone - * else is managing) which in turn can result in deadlock under - * extreme circumstances. Use @pool->assoc_mutex to synchronize - * manager against CPU hotplug. + * Managership is governed by two mutexes - manager_arb and + * manager_mutex. manager_arb handles arbitration of manager role. + * Anyone who successfully grabs manager_arb wins the arbitration + * and becomes the manager. mutex_trylock() on pool->manager_arb + * failure while holding pool->lock reliably indicates that someone + * else is managing the pool and the worker which failed trylock + * can proceed to executing work items. This means that anyone + * grabbing manager_arb is responsible for actually performing + * manager duties. If manager_arb is grabbed and released without + * actual management, the pool may stall indefinitely. * - * assoc_mutex would always be free unless CPU hotplug is in - * progress. trylock first without dropping @gcwq->lock. + * manager_mutex is used for exclusion of actual management + * operations. The holder of manager_mutex can be sure that none + * of management operations, including creation and destruction of + * workers, won't take place until the mutex is released. Because + * manager_mutex doesn't interfere with manager role arbitration, + * it is guaranteed that the pool's management, while may be + * delayed, won't be disturbed by someone else grabbing + * manager_mutex. */ - if (unlikely(!mutex_trylock(&pool->assoc_mutex))) { - spin_unlock_irq(&pool->gcwq->lock); - mutex_lock(&pool->assoc_mutex); - /* - * CPU hotplug could have happened while we were waiting - * for assoc_mutex. Hotplug itself can't handle us - * because manager isn't either on idle or busy list, and - * @gcwq's state and ours could have deviated. - * - * As hotplug is now excluded via assoc_mutex, we can - * simply try to bind. It will succeed or fail depending - * on @gcwq's current state. Try it and adjust - * %WORKER_UNBOUND accordingly. - */ - if (worker_maybe_bind_and_lock(worker)) - worker->flags &= ~WORKER_UNBOUND; - else - worker->flags |= WORKER_UNBOUND; + if (!mutex_trylock(&pool->manager_arb)) + return ret; + /* + * With manager arbitration won, manager_mutex would be free in + * most cases. trylock first without dropping @pool->lock. + */ + if (unlikely(!mutex_trylock(&pool->manager_mutex))) { + spin_unlock_irq(&pool->lock); + mutex_lock(&pool->manager_mutex); ret = true; } @@ -2140,8 +2071,8 @@ static bool manage_workers(struct worker *worker) ret |= maybe_destroy_workers(pool); ret |= maybe_create_worker(pool); - pool->flags &= ~POOL_MANAGING_WORKERS; - mutex_unlock(&pool->assoc_mutex); + mutex_unlock(&pool->manager_mutex); + mutex_unlock(&pool->manager_arb); return ret; } @@ -2157,18 +2088,15 @@ static bool manage_workers(struct worker *worker) * call this function to process a work. * * CONTEXT: - * spin_lock_irq(gcwq->lock) which is released and regrabbed. + * spin_lock_irq(pool->lock) which is released and regrabbed. */ static void process_one_work(struct worker *worker, struct work_struct *work) -__releases(&gcwq->lock) -__acquires(&gcwq->lock) +__releases(&pool->lock) +__acquires(&pool->lock) { - struct cpu_workqueue_struct *cwq = get_work_cwq(work); + struct pool_workqueue *pwq = get_work_pwq(work); struct worker_pool *pool = worker->pool; - struct global_cwq *gcwq = pool->gcwq; - struct hlist_head *bwh = busy_worker_head(gcwq, work); - bool cpu_intensive = cwq->wq->flags & WQ_CPU_INTENSIVE; - work_func_t f = work->func; + bool cpu_intensive = pwq->wq->flags & WQ_CPU_INTENSIVE; int work_color; struct worker *collision; #ifdef CONFIG_LOCKDEP @@ -2186,11 +2114,11 @@ __acquires(&gcwq->lock) /* * Ensure we're on the correct CPU. DISASSOCIATED test is * necessary to avoid spurious warnings from rescuers servicing the - * unbound or a disassociated gcwq. + * unbound or a disassociated pool. */ WARN_ON_ONCE(!(worker->flags & WORKER_UNBOUND) && - !(gcwq->flags & GCWQ_DISASSOCIATED) && - raw_smp_processor_id() != gcwq->cpu); + !(pool->flags & POOL_DISASSOCIATED) && + raw_smp_processor_id() != pool->cpu); /* * A single work shouldn't be executed concurrently by @@ -2198,7 +2126,7 @@ __acquires(&gcwq->lock) * already processing the work. If so, defer the work to the * currently executing one. */ - collision = __find_worker_executing_work(gcwq, bwh, work); + collision = find_worker_executing_work(pool, work); if (unlikely(collision)) { move_linked_works(work, &collision->scheduled, NULL); return; @@ -2206,9 +2134,10 @@ __acquires(&gcwq->lock) /* claim and dequeue */ debug_work_deactivate(work); - hlist_add_head(&worker->hentry, bwh); + hash_add(pool->busy_hash, &worker->hentry, (unsigned long)work); worker->current_work = work; - worker->current_cwq = cwq; + worker->current_func = work->func; + worker->current_pwq = pwq; work_color = get_work_color(work); list_del_init(&work->entry); @@ -2221,53 +2150,56 @@ __acquires(&gcwq->lock) worker_set_flags(worker, WORKER_CPU_INTENSIVE, true); /* - * Unbound gcwq isn't concurrency managed and work items should be + * Unbound pool isn't concurrency managed and work items should be * executed ASAP. Wake up another worker if necessary. */ if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool)) wake_up_worker(pool); /* - * Record the last CPU and clear PENDING which should be the last - * update to @work. Also, do this inside @gcwq->lock so that + * Record the last pool and clear PENDING which should be the last + * update to @work. Also, do this inside @pool->lock so that * PENDING and queued state changes happen together while IRQ is * disabled. */ - set_work_cpu_and_clear_pending(work, gcwq->cpu); + set_work_pool_and_clear_pending(work, pool->id); - spin_unlock_irq(&gcwq->lock); + spin_unlock_irq(&pool->lock); - lock_map_acquire_read(&cwq->wq->lockdep_map); + lock_map_acquire_read(&pwq->wq->lockdep_map); lock_map_acquire(&lockdep_map); trace_workqueue_execute_start(work); - f(work); + worker->current_func(work); /* * While we must be careful to not use "work" after this, the trace * point will only record its address. */ trace_workqueue_execute_end(work); lock_map_release(&lockdep_map); - lock_map_release(&cwq->wq->lockdep_map); + lock_map_release(&pwq->wq->lockdep_map); if (unlikely(in_atomic() || lockdep_depth(current) > 0)) { pr_err("BUG: workqueue leaked lock or atomic: %s/0x%08x/%d\n" " last function: %pf\n", - current->comm, preempt_count(), task_pid_nr(current), f); + current->comm, preempt_count(), task_pid_nr(current), + worker->current_func); debug_show_held_locks(current); dump_stack(); } - spin_lock_irq(&gcwq->lock); + spin_lock_irq(&pool->lock); /* clear cpu intensive status */ if (unlikely(cpu_intensive)) worker_clr_flags(worker, WORKER_CPU_INTENSIVE); /* we're done with it, release */ - hlist_del_init(&worker->hentry); + hash_del(&worker->hentry); worker->current_work = NULL; - worker->current_cwq = NULL; - cwq_dec_nr_in_flight(cwq, work_color); + worker->current_func = NULL; + worker->current_pwq = NULL; + worker->desc_valid = false; + pwq_dec_nr_in_flight(pwq, work_color); } /** @@ -2279,7 +2211,7 @@ __acquires(&gcwq->lock) * fetches a work from the top and executes it. * * CONTEXT: - * spin_lock_irq(gcwq->lock) which may be released and regrabbed + * spin_lock_irq(pool->lock) which may be released and regrabbed * multiple times. */ static void process_scheduled_works(struct worker *worker) @@ -2295,36 +2227,28 @@ static void process_scheduled_works(struct worker *worker) * worker_thread - the worker thread function * @__worker: self * - * The gcwq worker thread function. There's a single dynamic pool of - * these per each cpu. These workers process all works regardless of - * their specific target workqueue. The only exception is works which - * belong to workqueues with a rescuer which will be explained in - * rescuer_thread(). + * The worker thread function. All workers belong to a worker_pool - + * either a per-cpu one or dynamic unbound one. These workers process all + * work items regardless of their specific target workqueue. The only + * exception is work items which belong to workqueues with a rescuer which + * will be explained in rescuer_thread(). */ static int worker_thread(void *__worker) { struct worker *worker = __worker; struct worker_pool *pool = worker->pool; - struct global_cwq *gcwq = pool->gcwq; /* tell the scheduler that this is a workqueue worker */ worker->task->flags |= PF_WQ_WORKER; woke_up: - spin_lock_irq(&gcwq->lock); - - /* we are off idle list if destruction or rebind is requested */ - if (unlikely(list_empty(&worker->entry))) { - spin_unlock_irq(&gcwq->lock); - - /* if DIE is set, destruction is requested */ - if (worker->flags & WORKER_DIE) { - worker->task->flags &= ~PF_WQ_WORKER; - return 0; - } + spin_lock_irq(&pool->lock); - /* otherwise, rebind */ - idle_worker_rebind(worker); - goto woke_up; + /* am I supposed to die? */ + if (unlikely(worker->flags & WORKER_DIE)) { + spin_unlock_irq(&pool->lock); + WARN_ON_ONCE(!list_empty(&worker->entry)); + worker->task->flags &= ~PF_WQ_WORKER; + return 0; } worker_leave_idle(worker); @@ -2342,14 +2266,16 @@ recheck: * preparing to process a work or actually processing it. * Make sure nobody diddled with it while I was sleeping. */ - BUG_ON(!list_empty(&worker->scheduled)); + WARN_ON_ONCE(!list_empty(&worker->scheduled)); /* - * When control reaches this point, we're guaranteed to have - * at least one idle worker or that someone else has already - * assumed the manager role. + * Finish PREP stage. We're guaranteed to have at least one idle + * worker or that someone else has already assumed the manager + * role. This is where @worker starts participating in concurrency + * management if applicable and concurrency management is restored + * after being rebound. See rebind_workers() for details. */ - worker_clr_flags(worker, WORKER_PREP); + worker_clr_flags(worker, WORKER_PREP | WORKER_REBOUND); do { struct work_struct *work = @@ -2373,95 +2299,106 @@ sleep: goto recheck; /* - * gcwq->lock is held and there's no work to process and no - * need to manage, sleep. Workers are woken up only while - * holding gcwq->lock or from local cpu, so setting the - * current state before releasing gcwq->lock is enough to - * prevent losing any event. + * pool->lock is held and there's no work to process and no need to + * manage, sleep. Workers are woken up only while holding + * pool->lock or from local cpu, so setting the current state + * before releasing pool->lock is enough to prevent losing any + * event. */ worker_enter_idle(worker); __set_current_state(TASK_INTERRUPTIBLE); - spin_unlock_irq(&gcwq->lock); + spin_unlock_irq(&pool->lock); schedule(); goto woke_up; } /** * rescuer_thread - the rescuer thread function - * @__wq: the associated workqueue + * @__rescuer: self * * Workqueue rescuer thread function. There's one rescuer for each - * workqueue which has WQ_RESCUER set. + * workqueue which has WQ_MEM_RECLAIM set. * - * Regular work processing on a gcwq may block trying to create a new + * Regular work processing on a pool may block trying to create a new * worker which uses GFP_KERNEL allocation which has slight chance of * developing into deadlock if some works currently on the same queue * need to be processed to satisfy the GFP_KERNEL allocation. This is * the problem rescuer solves. * - * When such condition is possible, the gcwq summons rescuers of all - * workqueues which have works queued on the gcwq and let them process + * When such condition is possible, the pool summons rescuers of all + * workqueues which have works queued on the pool and let them process * those works so that forward progress can be guaranteed. * * This should happen rarely. */ -static int rescuer_thread(void *__wq) +static int rescuer_thread(void *__rescuer) { - struct workqueue_struct *wq = __wq; - struct worker *rescuer = wq->rescuer; + struct worker *rescuer = __rescuer; + struct workqueue_struct *wq = rescuer->rescue_wq; struct list_head *scheduled = &rescuer->scheduled; - bool is_unbound = wq->flags & WQ_UNBOUND; - unsigned int cpu; set_user_nice(current, RESCUER_NICE_LEVEL); + + /* + * Mark rescuer as worker too. As WORKER_PREP is never cleared, it + * doesn't participate in concurrency management. + */ + rescuer->task->flags |= PF_WQ_WORKER; repeat: set_current_state(TASK_INTERRUPTIBLE); if (kthread_should_stop()) { __set_current_state(TASK_RUNNING); + rescuer->task->flags &= ~PF_WQ_WORKER; return 0; } - /* - * See whether any cpu is asking for help. Unbounded - * workqueues use cpu 0 in mayday_mask for CPU_UNBOUND. - */ - for_each_mayday_cpu(cpu, wq->mayday_mask) { - unsigned int tcpu = is_unbound ? WORK_CPU_UNBOUND : cpu; - struct cpu_workqueue_struct *cwq = get_cwq(tcpu, wq); - struct worker_pool *pool = cwq->pool; - struct global_cwq *gcwq = pool->gcwq; + /* see whether any pwq is asking for help */ + spin_lock_irq(&wq_mayday_lock); + + while (!list_empty(&wq->maydays)) { + struct pool_workqueue *pwq = list_first_entry(&wq->maydays, + struct pool_workqueue, mayday_node); + struct worker_pool *pool = pwq->pool; struct work_struct *work, *n; __set_current_state(TASK_RUNNING); - mayday_clear_cpu(cpu, wq->mayday_mask); + list_del_init(&pwq->mayday_node); + + spin_unlock_irq(&wq_mayday_lock); /* migrate to the target cpu if possible */ + worker_maybe_bind_and_lock(pool); rescuer->pool = pool; - worker_maybe_bind_and_lock(rescuer); /* * Slurp in all works issued via this workqueue and * process'em. */ - BUG_ON(!list_empty(&rescuer->scheduled)); + WARN_ON_ONCE(!list_empty(&rescuer->scheduled)); list_for_each_entry_safe(work, n, &pool->worklist, entry) - if (get_work_cwq(work) == cwq) + if (get_work_pwq(work) == pwq) move_linked_works(work, scheduled, &n); process_scheduled_works(rescuer); /* - * Leave this gcwq. If keep_working() is %true, notify a + * Leave this pool. If keep_working() is %true, notify a * regular worker; otherwise, we end up with 0 concurrency * and stalling the execution. */ if (keep_working(pool)) wake_up_worker(pool); - spin_unlock_irq(&gcwq->lock); + rescuer->pool = NULL; + spin_unlock(&pool->lock); + spin_lock(&wq_mayday_lock); } + spin_unlock_irq(&wq_mayday_lock); + + /* rescuers should never participate in concurrency management */ + WARN_ON_ONCE(!(rescuer->flags & WORKER_NOT_RUNNING)); schedule(); goto repeat; } @@ -2479,7 +2416,7 @@ static void wq_barrier_func(struct work_struct *work) /** * insert_wq_barrier - insert a barrier work - * @cwq: cwq to insert barrier into + * @pwq: pwq to insert barrier into * @barr: wq_barrier to insert * @target: target work to attach @barr to * @worker: worker currently executing @target, NULL if @target is not executing @@ -2496,12 +2433,12 @@ static void wq_barrier_func(struct work_struct *work) * after a work with LINKED flag set. * * Note that when @worker is non-NULL, @target may be modified - * underneath us, so we can't reliably determine cwq from @target. + * underneath us, so we can't reliably determine pwq from @target. * * CONTEXT: - * spin_lock_irq(gcwq->lock). + * spin_lock_irq(pool->lock). */ -static void insert_wq_barrier(struct cpu_workqueue_struct *cwq, +static void insert_wq_barrier(struct pool_workqueue *pwq, struct wq_barrier *barr, struct work_struct *target, struct worker *worker) { @@ -2509,7 +2446,7 @@ static void insert_wq_barrier(struct cpu_workqueue_struct *cwq, unsigned int linked = 0; /* - * debugobject calls are safe here even with gcwq->lock locked + * debugobject calls are safe here even with pool->lock locked * as we know for sure that this will not trigger any of the * checks and call back into the fixup functions where we * might deadlock. @@ -2534,23 +2471,23 @@ static void insert_wq_barrier(struct cpu_workqueue_struct *cwq, } debug_work_activate(&barr->work); - insert_work(cwq, &barr->work, head, + insert_work(pwq, &barr->work, head, work_color_to_flags(WORK_NO_COLOR) | linked); } /** - * flush_workqueue_prep_cwqs - prepare cwqs for workqueue flushing + * flush_workqueue_prep_pwqs - prepare pwqs for workqueue flushing * @wq: workqueue being flushed * @flush_color: new flush color, < 0 for no-op * @work_color: new work color, < 0 for no-op * - * Prepare cwqs for workqueue flushing. + * Prepare pwqs for workqueue flushing. * - * If @flush_color is non-negative, flush_color on all cwqs should be - * -1. If no cwq has in-flight commands at the specified color, all - * cwq->flush_color's stay at -1 and %false is returned. If any cwq - * has in flight commands, its cwq->flush_color is set to - * @flush_color, @wq->nr_cwqs_to_flush is updated accordingly, cwq + * If @flush_color is non-negative, flush_color on all pwqs should be + * -1. If no pwq has in-flight commands at the specified color, all + * pwq->flush_color's stay at -1 and %false is returned. If any pwq + * has in flight commands, its pwq->flush_color is set to + * @flush_color, @wq->nr_pwqs_to_flush is updated accordingly, pwq * wakeup logic is armed and %true is returned. * * The caller should have initialized @wq->first_flusher prior to @@ -2558,53 +2495,52 @@ static void insert_wq_barrier(struct cpu_workqueue_struct *cwq, * @flush_color is negative, no flush color update is done and %false * is returned. * - * If @work_color is non-negative, all cwqs should have the same + * If @work_color is non-negative, all pwqs should have the same * work_color which is previous to @work_color and all will be * advanced to @work_color. * * CONTEXT: - * mutex_lock(wq->flush_mutex). + * mutex_lock(wq->mutex). * * RETURNS: * %true if @flush_color >= 0 and there's something to flush. %false * otherwise. */ -static bool flush_workqueue_prep_cwqs(struct workqueue_struct *wq, +static bool flush_workqueue_prep_pwqs(struct workqueue_struct *wq, int flush_color, int work_color) { bool wait = false; - unsigned int cpu; + struct pool_workqueue *pwq; if (flush_color >= 0) { - BUG_ON(atomic_read(&wq->nr_cwqs_to_flush)); - atomic_set(&wq->nr_cwqs_to_flush, 1); + WARN_ON_ONCE(atomic_read(&wq->nr_pwqs_to_flush)); + atomic_set(&wq->nr_pwqs_to_flush, 1); } - for_each_cwq_cpu(cpu, wq) { - struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); - struct global_cwq *gcwq = cwq->pool->gcwq; + for_each_pwq(pwq, wq) { + struct worker_pool *pool = pwq->pool; - spin_lock_irq(&gcwq->lock); + spin_lock_irq(&pool->lock); if (flush_color >= 0) { - BUG_ON(cwq->flush_color != -1); + WARN_ON_ONCE(pwq->flush_color != -1); - if (cwq->nr_in_flight[flush_color]) { - cwq->flush_color = flush_color; - atomic_inc(&wq->nr_cwqs_to_flush); + if (pwq->nr_in_flight[flush_color]) { + pwq->flush_color = flush_color; + atomic_inc(&wq->nr_pwqs_to_flush); wait = true; } } if (work_color >= 0) { - BUG_ON(work_color != work_next_color(cwq->work_color)); - cwq->work_color = work_color; + WARN_ON_ONCE(work_color != work_next_color(pwq->work_color)); + pwq->work_color = work_color; } - spin_unlock_irq(&gcwq->lock); + spin_unlock_irq(&pool->lock); } - if (flush_color >= 0 && atomic_dec_and_test(&wq->nr_cwqs_to_flush)) + if (flush_color >= 0 && atomic_dec_and_test(&wq->nr_pwqs_to_flush)) complete(&wq->first_flusher->done); return wait; @@ -2614,11 +2550,8 @@ static bool flush_workqueue_prep_cwqs(struct workqueue_struct *wq, * flush_workqueue - ensure that any scheduled work has run to completion. * @wq: workqueue to flush * - * Forces execution of the workqueue and blocks until its completion. - * This is typically used in driver shutdown handlers. - * - * We sleep until all works which were queued on entry have been handled, - * but we are not livelocked by new incoming ones. + * This function sleeps until all work items which were queued on entry + * have finished execution, but it is not livelocked by new incoming ones. */ void flush_workqueue(struct workqueue_struct *wq) { @@ -2632,7 +2565,7 @@ void flush_workqueue(struct workqueue_struct *wq) lock_map_acquire(&wq->lockdep_map); lock_map_release(&wq->lockdep_map); - mutex_lock(&wq->flush_mutex); + mutex_lock(&wq->mutex); /* * Start-to-wait phase @@ -2645,17 +2578,17 @@ void flush_workqueue(struct workqueue_struct *wq) * becomes our flush_color and work_color is advanced * by one. */ - BUG_ON(!list_empty(&wq->flusher_overflow)); + WARN_ON_ONCE(!list_empty(&wq->flusher_overflow)); this_flusher.flush_color = wq->work_color; wq->work_color = next_color; if (!wq->first_flusher) { /* no flush in progress, become the first flusher */ - BUG_ON(wq->flush_color != this_flusher.flush_color); + WARN_ON_ONCE(wq->flush_color != this_flusher.flush_color); wq->first_flusher = &this_flusher; - if (!flush_workqueue_prep_cwqs(wq, wq->flush_color, + if (!flush_workqueue_prep_pwqs(wq, wq->flush_color, wq->work_color)) { /* nothing to flush, done */ wq->flush_color = next_color; @@ -2664,9 +2597,9 @@ void flush_workqueue(struct workqueue_struct *wq) } } else { /* wait in queue */ - BUG_ON(wq->flush_color == this_flusher.flush_color); + WARN_ON_ONCE(wq->flush_color == this_flusher.flush_color); list_add_tail(&this_flusher.list, &wq->flusher_queue); - flush_workqueue_prep_cwqs(wq, -1, wq->work_color); + flush_workqueue_prep_pwqs(wq, -1, wq->work_color); } } else { /* @@ -2677,7 +2610,7 @@ void flush_workqueue(struct workqueue_struct *wq) list_add_tail(&this_flusher.list, &wq->flusher_overflow); } - mutex_unlock(&wq->flush_mutex); + mutex_unlock(&wq->mutex); wait_for_completion(&this_flusher.done); @@ -2690,7 +2623,7 @@ void flush_workqueue(struct workqueue_struct *wq) if (wq->first_flusher != &this_flusher) return; - mutex_lock(&wq->flush_mutex); + mutex_lock(&wq->mutex); /* we might have raced, check again with mutex held */ if (wq->first_flusher != &this_flusher) @@ -2698,8 +2631,8 @@ void flush_workqueue(struct workqueue_struct *wq) wq->first_flusher = NULL; - BUG_ON(!list_empty(&this_flusher.list)); - BUG_ON(wq->flush_color != this_flusher.flush_color); + WARN_ON_ONCE(!list_empty(&this_flusher.list)); + WARN_ON_ONCE(wq->flush_color != this_flusher.flush_color); while (true) { struct wq_flusher *next, *tmp; @@ -2712,8 +2645,8 @@ void flush_workqueue(struct workqueue_struct *wq) complete(&next->done); } - BUG_ON(!list_empty(&wq->flusher_overflow) && - wq->flush_color != work_next_color(wq->work_color)); + WARN_ON_ONCE(!list_empty(&wq->flusher_overflow) && + wq->flush_color != work_next_color(wq->work_color)); /* this flush_color is finished, advance by one */ wq->flush_color = work_next_color(wq->flush_color); @@ -2733,25 +2666,25 @@ void flush_workqueue(struct workqueue_struct *wq) list_splice_tail_init(&wq->flusher_overflow, &wq->flusher_queue); - flush_workqueue_prep_cwqs(wq, -1, wq->work_color); + flush_workqueue_prep_pwqs(wq, -1, wq->work_color); } if (list_empty(&wq->flusher_queue)) { - BUG_ON(wq->flush_color != wq->work_color); + WARN_ON_ONCE(wq->flush_color != wq->work_color); break; } /* * Need to flush more colors. Make the next flusher - * the new first flusher and arm cwqs. + * the new first flusher and arm pwqs. */ - BUG_ON(wq->flush_color == wq->work_color); - BUG_ON(wq->flush_color != next->flush_color); + WARN_ON_ONCE(wq->flush_color == wq->work_color); + WARN_ON_ONCE(wq->flush_color != next->flush_color); list_del_init(&next->list); wq->first_flusher = next; - if (flush_workqueue_prep_cwqs(wq, wq->flush_color, -1)) + if (flush_workqueue_prep_pwqs(wq, wq->flush_color, -1)) break; /* @@ -2762,7 +2695,7 @@ void flush_workqueue(struct workqueue_struct *wq) } out_unlock: - mutex_unlock(&wq->flush_mutex); + mutex_unlock(&wq->mutex); } EXPORT_SYMBOL_GPL(flush_workqueue); @@ -2780,76 +2713,77 @@ EXPORT_SYMBOL_GPL(flush_workqueue); void drain_workqueue(struct workqueue_struct *wq) { unsigned int flush_cnt = 0; - unsigned int cpu; + struct pool_workqueue *pwq; /* * __queue_work() needs to test whether there are drainers, is much * hotter than drain_workqueue() and already looks at @wq->flags. - * Use WQ_DRAINING so that queue doesn't have to check nr_drainers. + * Use __WQ_DRAINING so that queue doesn't have to check nr_drainers. */ - spin_lock(&workqueue_lock); + mutex_lock(&wq->mutex); if (!wq->nr_drainers++) - wq->flags |= WQ_DRAINING; - spin_unlock(&workqueue_lock); + wq->flags |= __WQ_DRAINING; + mutex_unlock(&wq->mutex); reflush: flush_workqueue(wq); - for_each_cwq_cpu(cpu, wq) { - struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); + mutex_lock(&wq->mutex); + + for_each_pwq(pwq, wq) { bool drained; - spin_lock_irq(&cwq->pool->gcwq->lock); - drained = !cwq->nr_active && list_empty(&cwq->delayed_works); - spin_unlock_irq(&cwq->pool->gcwq->lock); + spin_lock_irq(&pwq->pool->lock); + drained = !pwq->nr_active && list_empty(&pwq->delayed_works); + spin_unlock_irq(&pwq->pool->lock); if (drained) continue; if (++flush_cnt == 10 || (flush_cnt % 100 == 0 && flush_cnt <= 1000)) - pr_warn("workqueue %s: flush on destruction isn't complete after %u tries\n", + pr_warn("workqueue %s: drain_workqueue() isn't complete after %u tries\n", wq->name, flush_cnt); + + mutex_unlock(&wq->mutex); goto reflush; } - spin_lock(&workqueue_lock); if (!--wq->nr_drainers) - wq->flags &= ~WQ_DRAINING; - spin_unlock(&workqueue_lock); + wq->flags &= ~__WQ_DRAINING; + mutex_unlock(&wq->mutex); } EXPORT_SYMBOL_GPL(drain_workqueue); static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr) { struct worker *worker = NULL; - struct global_cwq *gcwq; - struct cpu_workqueue_struct *cwq; + struct worker_pool *pool; + struct pool_workqueue *pwq; might_sleep(); - gcwq = get_work_gcwq(work); - if (!gcwq) + + local_irq_disable(); + pool = get_work_pool(work); + if (!pool) { + local_irq_enable(); return false; + } - spin_lock_irq(&gcwq->lock); - if (!list_empty(&work->entry)) { - /* - * See the comment near try_to_grab_pending()->smp_rmb(). - * If it was re-queued to a different gcwq under us, we - * are not going to wait. - */ - smp_rmb(); - cwq = get_work_cwq(work); - if (unlikely(!cwq || gcwq != cwq->pool->gcwq)) + spin_lock(&pool->lock); + /* see the comment in try_to_grab_pending() with the same code */ + pwq = get_work_pwq(work); + if (pwq) { + if (unlikely(pwq->pool != pool)) goto already_gone; } else { - worker = find_worker_executing_work(gcwq, work); + worker = find_worker_executing_work(pool, work); if (!worker) goto already_gone; - cwq = worker->current_cwq; + pwq = worker->current_pwq; } - insert_wq_barrier(cwq, barr, work, worker); - spin_unlock_irq(&gcwq->lock); + insert_wq_barrier(pwq, barr, work, worker); + spin_unlock_irq(&pool->lock); /* * If @max_active is 1 or rescuer is in use, flushing another work @@ -2857,15 +2791,15 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr) * flusher is not running on the same workqueue by verifying write * access. */ - if (cwq->wq->saved_max_active == 1 || cwq->wq->flags & WQ_RESCUER) - lock_map_acquire(&cwq->wq->lockdep_map); + if (pwq->wq->saved_max_active == 1 || pwq->wq->rescuer) + lock_map_acquire(&pwq->wq->lockdep_map); else - lock_map_acquire_read(&cwq->wq->lockdep_map); - lock_map_release(&cwq->wq->lockdep_map); + lock_map_acquire_read(&pwq->wq->lockdep_map); + lock_map_release(&pwq->wq->lockdep_map); return true; already_gone: - spin_unlock_irq(&gcwq->lock); + spin_unlock_irq(&pool->lock); return false; } @@ -2961,8 +2895,7 @@ bool flush_delayed_work(struct delayed_work *dwork) { local_irq_disable(); if (del_timer_sync(&dwork->timer)) - __queue_work(dwork->cpu, - get_work_cwq(&dwork->work)->wq, &dwork->work); + __queue_work(dwork->cpu, dwork->wq, &dwork->work); local_irq_enable(); return flush_work(&dwork->work); } @@ -2992,7 +2925,8 @@ bool cancel_delayed_work(struct delayed_work *dwork) if (unlikely(ret < 0)) return false; - set_work_cpu_and_clear_pending(&dwork->work, work_cpu(&dwork->work)); + set_work_pool_and_clear_pending(&dwork->work, + get_work_pool_id(&dwork->work)); local_irq_restore(flags); return ret; } @@ -3014,66 +2948,6 @@ bool cancel_delayed_work_sync(struct delayed_work *dwork) EXPORT_SYMBOL(cancel_delayed_work_sync); /** - * schedule_work_on - put work task on a specific cpu - * @cpu: cpu to put the work task on - * @work: job to be done - * - * This puts a job on a specific cpu - */ -bool schedule_work_on(int cpu, struct work_struct *work) -{ - return queue_work_on(cpu, system_wq, work); -} -EXPORT_SYMBOL(schedule_work_on); - -/** - * schedule_work - put work task in global workqueue - * @work: job to be done - * - * Returns %false if @work was already on the kernel-global workqueue and - * %true otherwise. - * - * This puts a job in the kernel-global workqueue if it was not already - * queued and leaves it in the same position on the kernel-global - * workqueue otherwise. - */ -bool schedule_work(struct work_struct *work) -{ - return queue_work(system_wq, work); -} -EXPORT_SYMBOL(schedule_work); - -/** - * schedule_delayed_work_on - queue work in global workqueue on CPU after delay - * @cpu: cpu to use - * @dwork: job to be done - * @delay: number of jiffies to wait - * - * After waiting for a given time this puts a job in the kernel-global - * workqueue on the specified CPU. - */ -bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork, - unsigned long delay) -{ - return queue_delayed_work_on(cpu, system_wq, dwork, delay); -} -EXPORT_SYMBOL(schedule_delayed_work_on); - -/** - * schedule_delayed_work - put work task in global workqueue after delay - * @dwork: job to be done - * @delay: number of jiffies to wait or 0 for immediate execution - * - * After waiting for a given time this puts a job in the kernel-global - * workqueue. - */ -bool schedule_delayed_work(struct delayed_work *dwork, unsigned long delay) -{ - return queue_delayed_work(system_wq, dwork, delay); -} -EXPORT_SYMBOL(schedule_delayed_work); - -/** * schedule_on_each_cpu - execute a function synchronously on each online CPU * @func: the function to call * @@ -3166,51 +3040,1025 @@ int execute_in_process_context(work_func_t fn, struct execute_work *ew) } EXPORT_SYMBOL_GPL(execute_in_process_context); -int keventd_up(void) +#ifdef CONFIG_SYSFS +/* + * Workqueues with WQ_SYSFS flag set is visible to userland via + * /sys/bus/workqueue/devices/WQ_NAME. All visible workqueues have the + * following attributes. + * + * per_cpu RO bool : whether the workqueue is per-cpu or unbound + * max_active RW int : maximum number of in-flight work items + * + * Unbound workqueues have the following extra attributes. + * + * id RO int : the associated pool ID + * nice RW int : nice value of the workers + * cpumask RW mask : bitmask of allowed CPUs for the workers + */ +struct wq_device { + struct workqueue_struct *wq; + struct device dev; +}; + +static struct workqueue_struct *dev_to_wq(struct device *dev) +{ + struct wq_device *wq_dev = container_of(dev, struct wq_device, dev); + + return wq_dev->wq; +} + +static ssize_t wq_per_cpu_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct workqueue_struct *wq = dev_to_wq(dev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", (bool)!(wq->flags & WQ_UNBOUND)); +} + +static ssize_t wq_max_active_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct workqueue_struct *wq = dev_to_wq(dev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", wq->saved_max_active); +} + +static ssize_t wq_max_active_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct workqueue_struct *wq = dev_to_wq(dev); + int val; + + if (sscanf(buf, "%d", &val) != 1 || val <= 0) + return -EINVAL; + + workqueue_set_max_active(wq, val); + return count; +} + +static struct device_attribute wq_sysfs_attrs[] = { + __ATTR(per_cpu, 0444, wq_per_cpu_show, NULL), + __ATTR(max_active, 0644, wq_max_active_show, wq_max_active_store), + __ATTR_NULL, +}; + +static ssize_t wq_pool_ids_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct workqueue_struct *wq = dev_to_wq(dev); + const char *delim = ""; + int node, written = 0; + + rcu_read_lock_sched(); + for_each_node(node) { + written += scnprintf(buf + written, PAGE_SIZE - written, + "%s%d:%d", delim, node, + unbound_pwq_by_node(wq, node)->pool->id); + delim = " "; + } + written += scnprintf(buf + written, PAGE_SIZE - written, "\n"); + rcu_read_unlock_sched(); + + return written; +} + +static ssize_t wq_nice_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct workqueue_struct *wq = dev_to_wq(dev); + int written; + + mutex_lock(&wq->mutex); + written = scnprintf(buf, PAGE_SIZE, "%d\n", wq->unbound_attrs->nice); + mutex_unlock(&wq->mutex); + + return written; +} + +/* prepare workqueue_attrs for sysfs store operations */ +static struct workqueue_attrs *wq_sysfs_prep_attrs(struct workqueue_struct *wq) +{ + struct workqueue_attrs *attrs; + + attrs = alloc_workqueue_attrs(GFP_KERNEL); + if (!attrs) + return NULL; + + mutex_lock(&wq->mutex); + copy_workqueue_attrs(attrs, wq->unbound_attrs); + mutex_unlock(&wq->mutex); + return attrs; +} + +static ssize_t wq_nice_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct workqueue_struct *wq = dev_to_wq(dev); + struct workqueue_attrs *attrs; + int ret; + + attrs = wq_sysfs_prep_attrs(wq); + if (!attrs) + return -ENOMEM; + + if (sscanf(buf, "%d", &attrs->nice) == 1 && + attrs->nice >= -20 && attrs->nice <= 19) + ret = apply_workqueue_attrs(wq, attrs); + else + ret = -EINVAL; + + free_workqueue_attrs(attrs); + return ret ?: count; +} + +static ssize_t wq_cpumask_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct workqueue_struct *wq = dev_to_wq(dev); + int written; + + mutex_lock(&wq->mutex); + written = cpumask_scnprintf(buf, PAGE_SIZE, wq->unbound_attrs->cpumask); + mutex_unlock(&wq->mutex); + + written += scnprintf(buf + written, PAGE_SIZE - written, "\n"); + return written; +} + +static ssize_t wq_cpumask_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) { - return system_wq != NULL; + struct workqueue_struct *wq = dev_to_wq(dev); + struct workqueue_attrs *attrs; + int ret; + + attrs = wq_sysfs_prep_attrs(wq); + if (!attrs) + return -ENOMEM; + + ret = cpumask_parse(buf, attrs->cpumask); + if (!ret) + ret = apply_workqueue_attrs(wq, attrs); + + free_workqueue_attrs(attrs); + return ret ?: count; } -static int alloc_cwqs(struct workqueue_struct *wq) +static ssize_t wq_numa_show(struct device *dev, struct device_attribute *attr, + char *buf) { + struct workqueue_struct *wq = dev_to_wq(dev); + int written; + + mutex_lock(&wq->mutex); + written = scnprintf(buf, PAGE_SIZE, "%d\n", + !wq->unbound_attrs->no_numa); + mutex_unlock(&wq->mutex); + + return written; +} + +static ssize_t wq_numa_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct workqueue_struct *wq = dev_to_wq(dev); + struct workqueue_attrs *attrs; + int v, ret; + + attrs = wq_sysfs_prep_attrs(wq); + if (!attrs) + return -ENOMEM; + + ret = -EINVAL; + if (sscanf(buf, "%d", &v) == 1) { + attrs->no_numa = !v; + ret = apply_workqueue_attrs(wq, attrs); + } + + free_workqueue_attrs(attrs); + return ret ?: count; +} + +static struct device_attribute wq_sysfs_unbound_attrs[] = { + __ATTR(pool_ids, 0444, wq_pool_ids_show, NULL), + __ATTR(nice, 0644, wq_nice_show, wq_nice_store), + __ATTR(cpumask, 0644, wq_cpumask_show, wq_cpumask_store), + __ATTR(numa, 0644, wq_numa_show, wq_numa_store), + __ATTR_NULL, +}; + +static struct bus_type wq_subsys = { + .name = "workqueue", + .dev_attrs = wq_sysfs_attrs, +}; + +static int __init wq_sysfs_init(void) +{ + return subsys_virtual_register(&wq_subsys, NULL); +} +core_initcall(wq_sysfs_init); + +static void wq_device_release(struct device *dev) +{ + struct wq_device *wq_dev = container_of(dev, struct wq_device, dev); + + kfree(wq_dev); +} + +/** + * workqueue_sysfs_register - make a workqueue visible in sysfs + * @wq: the workqueue to register + * + * Expose @wq in sysfs under /sys/bus/workqueue/devices. + * alloc_workqueue*() automatically calls this function if WQ_SYSFS is set + * which is the preferred method. + * + * Workqueue user should use this function directly iff it wants to apply + * workqueue_attrs before making the workqueue visible in sysfs; otherwise, + * apply_workqueue_attrs() may race against userland updating the + * attributes. + * + * Returns 0 on success, -errno on failure. + */ +int workqueue_sysfs_register(struct workqueue_struct *wq) +{ + struct wq_device *wq_dev; + int ret; + /* - * cwqs are forced aligned according to WORK_STRUCT_FLAG_BITS. - * Make sure that the alignment isn't lower than that of - * unsigned long long. + * Adjusting max_active or creating new pwqs by applyting + * attributes breaks ordering guarantee. Disallow exposing ordered + * workqueues. */ - const size_t size = sizeof(struct cpu_workqueue_struct); - const size_t align = max_t(size_t, 1 << WORK_STRUCT_FLAG_BITS, - __alignof__(unsigned long long)); + if (WARN_ON(wq->flags & __WQ_ORDERED)) + return -EINVAL; - if (!(wq->flags & WQ_UNBOUND)) - wq->cpu_wq.pcpu = __alloc_percpu(size, align); - else { - void *ptr; + wq->wq_dev = wq_dev = kzalloc(sizeof(*wq_dev), GFP_KERNEL); + if (!wq_dev) + return -ENOMEM; + + wq_dev->wq = wq; + wq_dev->dev.bus = &wq_subsys; + wq_dev->dev.init_name = wq->name; + wq_dev->dev.release = wq_device_release; + + /* + * unbound_attrs are created separately. Suppress uevent until + * everything is ready. + */ + dev_set_uevent_suppress(&wq_dev->dev, true); + + ret = device_register(&wq_dev->dev); + if (ret) { + kfree(wq_dev); + wq->wq_dev = NULL; + return ret; + } + + if (wq->flags & WQ_UNBOUND) { + struct device_attribute *attr; + + for (attr = wq_sysfs_unbound_attrs; attr->attr.name; attr++) { + ret = device_create_file(&wq_dev->dev, attr); + if (ret) { + device_unregister(&wq_dev->dev); + wq->wq_dev = NULL; + return ret; + } + } + } + + kobject_uevent(&wq_dev->dev.kobj, KOBJ_ADD); + return 0; +} + +/** + * workqueue_sysfs_unregister - undo workqueue_sysfs_register() + * @wq: the workqueue to unregister + * + * If @wq is registered to sysfs by workqueue_sysfs_register(), unregister. + */ +static void workqueue_sysfs_unregister(struct workqueue_struct *wq) +{ + struct wq_device *wq_dev = wq->wq_dev; + + if (!wq->wq_dev) + return; + + wq->wq_dev = NULL; + device_unregister(&wq_dev->dev); +} +#else /* CONFIG_SYSFS */ +static void workqueue_sysfs_unregister(struct workqueue_struct *wq) { } +#endif /* CONFIG_SYSFS */ + +/** + * free_workqueue_attrs - free a workqueue_attrs + * @attrs: workqueue_attrs to free + * + * Undo alloc_workqueue_attrs(). + */ +void free_workqueue_attrs(struct workqueue_attrs *attrs) +{ + if (attrs) { + free_cpumask_var(attrs->cpumask); + kfree(attrs); + } +} + +/** + * alloc_workqueue_attrs - allocate a workqueue_attrs + * @gfp_mask: allocation mask to use + * + * Allocate a new workqueue_attrs, initialize with default settings and + * return it. Returns NULL on failure. + */ +struct workqueue_attrs *alloc_workqueue_attrs(gfp_t gfp_mask) +{ + struct workqueue_attrs *attrs; + + attrs = kzalloc(sizeof(*attrs), gfp_mask); + if (!attrs) + goto fail; + if (!alloc_cpumask_var(&attrs->cpumask, gfp_mask)) + goto fail; + + cpumask_copy(attrs->cpumask, cpu_possible_mask); + return attrs; +fail: + free_workqueue_attrs(attrs); + return NULL; +} + +static void copy_workqueue_attrs(struct workqueue_attrs *to, + const struct workqueue_attrs *from) +{ + to->nice = from->nice; + cpumask_copy(to->cpumask, from->cpumask); +} + +/* hash value of the content of @attr */ +static u32 wqattrs_hash(const struct workqueue_attrs *attrs) +{ + u32 hash = 0; + + hash = jhash_1word(attrs->nice, hash); + hash = jhash(cpumask_bits(attrs->cpumask), + BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long), hash); + return hash; +} + +/* content equality test */ +static bool wqattrs_equal(const struct workqueue_attrs *a, + const struct workqueue_attrs *b) +{ + if (a->nice != b->nice) + return false; + if (!cpumask_equal(a->cpumask, b->cpumask)) + return false; + return true; +} + +/** + * init_worker_pool - initialize a newly zalloc'd worker_pool + * @pool: worker_pool to initialize + * + * Initiailize a newly zalloc'd @pool. It also allocates @pool->attrs. + * Returns 0 on success, -errno on failure. Even on failure, all fields + * inside @pool proper are initialized and put_unbound_pool() can be called + * on @pool safely to release it. + */ +static int init_worker_pool(struct worker_pool *pool) +{ + spin_lock_init(&pool->lock); + pool->id = -1; + pool->cpu = -1; + pool->node = NUMA_NO_NODE; + pool->flags |= POOL_DISASSOCIATED; + INIT_LIST_HEAD(&pool->worklist); + INIT_LIST_HEAD(&pool->idle_list); + hash_init(pool->busy_hash); + + init_timer_deferrable(&pool->idle_timer); + pool->idle_timer.function = idle_worker_timeout; + pool->idle_timer.data = (unsigned long)pool; + + setup_timer(&pool->mayday_timer, pool_mayday_timeout, + (unsigned long)pool); + + mutex_init(&pool->manager_arb); + mutex_init(&pool->manager_mutex); + idr_init(&pool->worker_idr); + + INIT_HLIST_NODE(&pool->hash_node); + pool->refcnt = 1; + + /* shouldn't fail above this point */ + pool->attrs = alloc_workqueue_attrs(GFP_KERNEL); + if (!pool->attrs) + return -ENOMEM; + return 0; +} + +static void rcu_free_pool(struct rcu_head *rcu) +{ + struct worker_pool *pool = container_of(rcu, struct worker_pool, rcu); + + idr_destroy(&pool->worker_idr); + free_workqueue_attrs(pool->attrs); + kfree(pool); +} + +/** + * put_unbound_pool - put a worker_pool + * @pool: worker_pool to put + * + * Put @pool. If its refcnt reaches zero, it gets destroyed in sched-RCU + * safe manner. get_unbound_pool() calls this function on its failure path + * and this function should be able to release pools which went through, + * successfully or not, init_worker_pool(). + * + * Should be called with wq_pool_mutex held. + */ +static void put_unbound_pool(struct worker_pool *pool) +{ + struct worker *worker; + + lockdep_assert_held(&wq_pool_mutex); + + if (--pool->refcnt) + return; + + /* sanity checks */ + if (WARN_ON(!(pool->flags & POOL_DISASSOCIATED)) || + WARN_ON(!list_empty(&pool->worklist))) + return; + + /* release id and unhash */ + if (pool->id >= 0) + idr_remove(&worker_pool_idr, pool->id); + hash_del(&pool->hash_node); + + /* + * Become the manager and destroy all workers. Grabbing + * manager_arb prevents @pool's workers from blocking on + * manager_mutex. + */ + mutex_lock(&pool->manager_arb); + mutex_lock(&pool->manager_mutex); + spin_lock_irq(&pool->lock); + + while ((worker = first_worker(pool))) + destroy_worker(worker); + WARN_ON(pool->nr_workers || pool->nr_idle); + + spin_unlock_irq(&pool->lock); + mutex_unlock(&pool->manager_mutex); + mutex_unlock(&pool->manager_arb); + + /* shut down the timers */ + del_timer_sync(&pool->idle_timer); + del_timer_sync(&pool->mayday_timer); + + /* sched-RCU protected to allow dereferences from get_work_pool() */ + call_rcu_sched(&pool->rcu, rcu_free_pool); +} + +/** + * get_unbound_pool - get a worker_pool with the specified attributes + * @attrs: the attributes of the worker_pool to get + * + * Obtain a worker_pool which has the same attributes as @attrs, bump the + * reference count and return it. If there already is a matching + * worker_pool, it will be used; otherwise, this function attempts to + * create a new one. On failure, returns NULL. + * + * Should be called with wq_pool_mutex held. + */ +static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs) +{ + u32 hash = wqattrs_hash(attrs); + struct worker_pool *pool; + int node; + + lockdep_assert_held(&wq_pool_mutex); + + /* do we already have a matching pool? */ + hash_for_each_possible(unbound_pool_hash, pool, hash_node, hash) { + if (wqattrs_equal(pool->attrs, attrs)) { + pool->refcnt++; + goto out_unlock; + } + } + + /* nope, create a new one */ + pool = kzalloc(sizeof(*pool), GFP_KERNEL); + if (!pool || init_worker_pool(pool) < 0) + goto fail; + + if (workqueue_freezing) + pool->flags |= POOL_FREEZING; + + lockdep_set_subclass(&pool->lock, 1); /* see put_pwq() */ + copy_workqueue_attrs(pool->attrs, attrs); + + /* if cpumask is contained inside a NUMA node, we belong to that node */ + if (wq_numa_enabled) { + for_each_node(node) { + if (cpumask_subset(pool->attrs->cpumask, + wq_numa_possible_cpumask[node])) { + pool->node = node; + break; + } + } + } + + if (worker_pool_assign_id(pool) < 0) + goto fail; + + /* create and start the initial worker */ + if (create_and_start_worker(pool) < 0) + goto fail; + + /* install */ + hash_add(unbound_pool_hash, &pool->hash_node, hash); +out_unlock: + return pool; +fail: + if (pool) + put_unbound_pool(pool); + return NULL; +} + +static void rcu_free_pwq(struct rcu_head *rcu) +{ + kmem_cache_free(pwq_cache, + container_of(rcu, struct pool_workqueue, rcu)); +} + +/* + * Scheduled on system_wq by put_pwq() when an unbound pwq hits zero refcnt + * and needs to be destroyed. + */ +static void pwq_unbound_release_workfn(struct work_struct *work) +{ + struct pool_workqueue *pwq = container_of(work, struct pool_workqueue, + unbound_release_work); + struct workqueue_struct *wq = pwq->wq; + struct worker_pool *pool = pwq->pool; + bool is_last; + + if (WARN_ON_ONCE(!(wq->flags & WQ_UNBOUND))) + return; + + /* + * Unlink @pwq. Synchronization against wq->mutex isn't strictly + * necessary on release but do it anyway. It's easier to verify + * and consistent with the linking path. + */ + mutex_lock(&wq->mutex); + list_del_rcu(&pwq->pwqs_node); + is_last = list_empty(&wq->pwqs); + mutex_unlock(&wq->mutex); + + mutex_lock(&wq_pool_mutex); + put_unbound_pool(pool); + mutex_unlock(&wq_pool_mutex); + + call_rcu_sched(&pwq->rcu, rcu_free_pwq); + + /* + * If we're the last pwq going away, @wq is already dead and no one + * is gonna access it anymore. Free it. + */ + if (is_last) { + free_workqueue_attrs(wq->unbound_attrs); + kfree(wq); + } +} + +/** + * pwq_adjust_max_active - update a pwq's max_active to the current setting + * @pwq: target pool_workqueue + * + * If @pwq isn't freezing, set @pwq->max_active to the associated + * workqueue's saved_max_active and activate delayed work items + * accordingly. If @pwq is freezing, clear @pwq->max_active to zero. + */ +static void pwq_adjust_max_active(struct pool_workqueue *pwq) +{ + struct workqueue_struct *wq = pwq->wq; + bool freezable = wq->flags & WQ_FREEZABLE; + + /* for @wq->saved_max_active */ + lockdep_assert_held(&wq->mutex); + + /* fast exit for non-freezable wqs */ + if (!freezable && pwq->max_active == wq->saved_max_active) + return; + + spin_lock_irq(&pwq->pool->lock); + + if (!freezable || !(pwq->pool->flags & POOL_FREEZING)) { + pwq->max_active = wq->saved_max_active; + + while (!list_empty(&pwq->delayed_works) && + pwq->nr_active < pwq->max_active) + pwq_activate_first_delayed(pwq); /* - * Allocate enough room to align cwq and put an extra - * pointer at the end pointing back to the originally - * allocated pointer which will be used for free. + * Need to kick a worker after thawed or an unbound wq's + * max_active is bumped. It's a slow path. Do it always. */ - ptr = kzalloc(size + align + sizeof(void *), GFP_KERNEL); - if (ptr) { - wq->cpu_wq.single = PTR_ALIGN(ptr, align); - *(void **)(wq->cpu_wq.single + 1) = ptr; + wake_up_worker(pwq->pool); + } else { + pwq->max_active = 0; + } + + spin_unlock_irq(&pwq->pool->lock); +} + +/* initialize newly alloced @pwq which is associated with @wq and @pool */ +static void init_pwq(struct pool_workqueue *pwq, struct workqueue_struct *wq, + struct worker_pool *pool) +{ + BUG_ON((unsigned long)pwq & WORK_STRUCT_FLAG_MASK); + + memset(pwq, 0, sizeof(*pwq)); + + pwq->pool = pool; + pwq->wq = wq; + pwq->flush_color = -1; + pwq->refcnt = 1; + INIT_LIST_HEAD(&pwq->delayed_works); + INIT_LIST_HEAD(&pwq->pwqs_node); + INIT_LIST_HEAD(&pwq->mayday_node); + INIT_WORK(&pwq->unbound_release_work, pwq_unbound_release_workfn); +} + +/* sync @pwq with the current state of its associated wq and link it */ +static void link_pwq(struct pool_workqueue *pwq) +{ + struct workqueue_struct *wq = pwq->wq; + + lockdep_assert_held(&wq->mutex); + + /* may be called multiple times, ignore if already linked */ + if (!list_empty(&pwq->pwqs_node)) + return; + + /* + * Set the matching work_color. This is synchronized with + * wq->mutex to avoid confusing flush_workqueue(). + */ + pwq->work_color = wq->work_color; + + /* sync max_active to the current setting */ + pwq_adjust_max_active(pwq); + + /* link in @pwq */ + list_add_rcu(&pwq->pwqs_node, &wq->pwqs); +} + +/* obtain a pool matching @attr and create a pwq associating the pool and @wq */ +static struct pool_workqueue *alloc_unbound_pwq(struct workqueue_struct *wq, + const struct workqueue_attrs *attrs) +{ + struct worker_pool *pool; + struct pool_workqueue *pwq; + + lockdep_assert_held(&wq_pool_mutex); + + pool = get_unbound_pool(attrs); + if (!pool) + return NULL; + + pwq = kmem_cache_alloc_node(pwq_cache, GFP_KERNEL, pool->node); + if (!pwq) { + put_unbound_pool(pool); + return NULL; + } + + init_pwq(pwq, wq, pool); + return pwq; +} + +/* undo alloc_unbound_pwq(), used only in the error path */ +static void free_unbound_pwq(struct pool_workqueue *pwq) +{ + lockdep_assert_held(&wq_pool_mutex); + + if (pwq) { + put_unbound_pool(pwq->pool); + kmem_cache_free(pwq_cache, pwq); + } +} + +/** + * wq_calc_node_mask - calculate a wq_attrs' cpumask for the specified node + * @attrs: the wq_attrs of interest + * @node: the target NUMA node + * @cpu_going_down: if >= 0, the CPU to consider as offline + * @cpumask: outarg, the resulting cpumask + * + * Calculate the cpumask a workqueue with @attrs should use on @node. If + * @cpu_going_down is >= 0, that cpu is considered offline during + * calculation. The result is stored in @cpumask. This function returns + * %true if the resulting @cpumask is different from @attrs->cpumask, + * %false if equal. + * + * If NUMA affinity is not enabled, @attrs->cpumask is always used. If + * enabled and @node has online CPUs requested by @attrs, the returned + * cpumask is the intersection of the possible CPUs of @node and + * @attrs->cpumask. + * + * The caller is responsible for ensuring that the cpumask of @node stays + * stable. + */ +static bool wq_calc_node_cpumask(const struct workqueue_attrs *attrs, int node, + int cpu_going_down, cpumask_t *cpumask) +{ + if (!wq_numa_enabled || attrs->no_numa) + goto use_dfl; + + /* does @node have any online CPUs @attrs wants? */ + cpumask_and(cpumask, cpumask_of_node(node), attrs->cpumask); + if (cpu_going_down >= 0) + cpumask_clear_cpu(cpu_going_down, cpumask); + + if (cpumask_empty(cpumask)) + goto use_dfl; + + /* yeap, return possible CPUs in @node that @attrs wants */ + cpumask_and(cpumask, attrs->cpumask, wq_numa_possible_cpumask[node]); + return !cpumask_equal(cpumask, attrs->cpumask); + +use_dfl: + cpumask_copy(cpumask, attrs->cpumask); + return false; +} + +/* install @pwq into @wq's numa_pwq_tbl[] for @node and return the old pwq */ +static struct pool_workqueue *numa_pwq_tbl_install(struct workqueue_struct *wq, + int node, + struct pool_workqueue *pwq) +{ + struct pool_workqueue *old_pwq; + + lockdep_assert_held(&wq->mutex); + + /* link_pwq() can handle duplicate calls */ + link_pwq(pwq); + + old_pwq = rcu_access_pointer(wq->numa_pwq_tbl[node]); + rcu_assign_pointer(wq->numa_pwq_tbl[node], pwq); + return old_pwq; +} + +/** + * apply_workqueue_attrs - apply new workqueue_attrs to an unbound workqueue + * @wq: the target workqueue + * @attrs: the workqueue_attrs to apply, allocated with alloc_workqueue_attrs() + * + * Apply @attrs to an unbound workqueue @wq. Unless disabled, on NUMA + * machines, this function maps a separate pwq to each NUMA node with + * possibles CPUs in @attrs->cpumask so that work items are affine to the + * NUMA node it was issued on. Older pwqs are released as in-flight work + * items finish. Note that a work item which repeatedly requeues itself + * back-to-back will stay on its current pwq. + * + * Performs GFP_KERNEL allocations. Returns 0 on success and -errno on + * failure. + */ +int apply_workqueue_attrs(struct workqueue_struct *wq, + const struct workqueue_attrs *attrs) +{ + struct workqueue_attrs *new_attrs, *tmp_attrs; + struct pool_workqueue **pwq_tbl, *dfl_pwq; + int node, ret; + + /* only unbound workqueues can change attributes */ + if (WARN_ON(!(wq->flags & WQ_UNBOUND))) + return -EINVAL; + + /* creating multiple pwqs breaks ordering guarantee */ + if (WARN_ON((wq->flags & __WQ_ORDERED) && !list_empty(&wq->pwqs))) + return -EINVAL; + + pwq_tbl = kzalloc(wq_numa_tbl_len * sizeof(pwq_tbl[0]), GFP_KERNEL); + new_attrs = alloc_workqueue_attrs(GFP_KERNEL); + tmp_attrs = alloc_workqueue_attrs(GFP_KERNEL); + if (!pwq_tbl || !new_attrs || !tmp_attrs) + goto enomem; + + /* make a copy of @attrs and sanitize it */ + copy_workqueue_attrs(new_attrs, attrs); + cpumask_and(new_attrs->cpumask, new_attrs->cpumask, cpu_possible_mask); + + /* + * We may create multiple pwqs with differing cpumasks. Make a + * copy of @new_attrs which will be modified and used to obtain + * pools. + */ + copy_workqueue_attrs(tmp_attrs, new_attrs); + + /* + * CPUs should stay stable across pwq creations and installations. + * Pin CPUs, determine the target cpumask for each node and create + * pwqs accordingly. + */ + get_online_cpus(); + + mutex_lock(&wq_pool_mutex); + + /* + * If something goes wrong during CPU up/down, we'll fall back to + * the default pwq covering whole @attrs->cpumask. Always create + * it even if we don't use it immediately. + */ + dfl_pwq = alloc_unbound_pwq(wq, new_attrs); + if (!dfl_pwq) + goto enomem_pwq; + + for_each_node(node) { + if (wq_calc_node_cpumask(attrs, node, -1, tmp_attrs->cpumask)) { + pwq_tbl[node] = alloc_unbound_pwq(wq, tmp_attrs); + if (!pwq_tbl[node]) + goto enomem_pwq; + } else { + dfl_pwq->refcnt++; + pwq_tbl[node] = dfl_pwq; } } - /* just in case, make sure it's actually aligned */ - BUG_ON(!IS_ALIGNED(wq->cpu_wq.v, align)); - return wq->cpu_wq.v ? 0 : -ENOMEM; + mutex_unlock(&wq_pool_mutex); + + /* all pwqs have been created successfully, let's install'em */ + mutex_lock(&wq->mutex); + + copy_workqueue_attrs(wq->unbound_attrs, new_attrs); + + /* save the previous pwq and install the new one */ + for_each_node(node) + pwq_tbl[node] = numa_pwq_tbl_install(wq, node, pwq_tbl[node]); + + /* @dfl_pwq might not have been used, ensure it's linked */ + link_pwq(dfl_pwq); + swap(wq->dfl_pwq, dfl_pwq); + + mutex_unlock(&wq->mutex); + + /* put the old pwqs */ + for_each_node(node) + put_pwq_unlocked(pwq_tbl[node]); + put_pwq_unlocked(dfl_pwq); + + put_online_cpus(); + ret = 0; + /* fall through */ +out_free: + free_workqueue_attrs(tmp_attrs); + free_workqueue_attrs(new_attrs); + kfree(pwq_tbl); + return ret; + +enomem_pwq: + free_unbound_pwq(dfl_pwq); + for_each_node(node) + if (pwq_tbl && pwq_tbl[node] != dfl_pwq) + free_unbound_pwq(pwq_tbl[node]); + mutex_unlock(&wq_pool_mutex); + put_online_cpus(); +enomem: + ret = -ENOMEM; + goto out_free; } -static void free_cwqs(struct workqueue_struct *wq) +/** + * wq_update_unbound_numa - update NUMA affinity of a wq for CPU hot[un]plug + * @wq: the target workqueue + * @cpu: the CPU coming up or going down + * @online: whether @cpu is coming up or going down + * + * This function is to be called from %CPU_DOWN_PREPARE, %CPU_ONLINE and + * %CPU_DOWN_FAILED. @cpu is being hot[un]plugged, update NUMA affinity of + * @wq accordingly. + * + * If NUMA affinity can't be adjusted due to memory allocation failure, it + * falls back to @wq->dfl_pwq which may not be optimal but is always + * correct. + * + * Note that when the last allowed CPU of a NUMA node goes offline for a + * workqueue with a cpumask spanning multiple nodes, the workers which were + * already executing the work items for the workqueue will lose their CPU + * affinity and may execute on any CPU. This is similar to how per-cpu + * workqueues behave on CPU_DOWN. If a workqueue user wants strict + * affinity, it's the user's responsibility to flush the work item from + * CPU_DOWN_PREPARE. + */ +static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu, + bool online) { - if (!(wq->flags & WQ_UNBOUND)) - free_percpu(wq->cpu_wq.pcpu); - else if (wq->cpu_wq.single) { - /* the pointer to free is stored right after the cwq */ - kfree(*(void **)(wq->cpu_wq.single + 1)); + int node = cpu_to_node(cpu); + int cpu_off = online ? -1 : cpu; + struct pool_workqueue *old_pwq = NULL, *pwq; + struct workqueue_attrs *target_attrs; + cpumask_t *cpumask; + + lockdep_assert_held(&wq_pool_mutex); + + if (!wq_numa_enabled || !(wq->flags & WQ_UNBOUND)) + return; + + /* + * We don't wanna alloc/free wq_attrs for each wq for each CPU. + * Let's use a preallocated one. The following buf is protected by + * CPU hotplug exclusion. + */ + target_attrs = wq_update_unbound_numa_attrs_buf; + cpumask = target_attrs->cpumask; + + mutex_lock(&wq->mutex); + if (wq->unbound_attrs->no_numa) + goto out_unlock; + + copy_workqueue_attrs(target_attrs, wq->unbound_attrs); + pwq = unbound_pwq_by_node(wq, node); + + /* + * Let's determine what needs to be done. If the target cpumask is + * different from wq's, we need to compare it to @pwq's and create + * a new one if they don't match. If the target cpumask equals + * wq's, the default pwq should be used. If @pwq is already the + * default one, nothing to do; otherwise, install the default one. + */ + if (wq_calc_node_cpumask(wq->unbound_attrs, node, cpu_off, cpumask)) { + if (cpumask_equal(cpumask, pwq->pool->attrs->cpumask)) + goto out_unlock; + } else { + if (pwq == wq->dfl_pwq) + goto out_unlock; + else + goto use_dfl_pwq; + } + + mutex_unlock(&wq->mutex); + + /* create a new pwq */ + pwq = alloc_unbound_pwq(wq, target_attrs); + if (!pwq) { + pr_warning("workqueue: allocation failed while updating NUMA affinity of \"%s\"\n", + wq->name); + goto out_unlock; + } + + /* + * Install the new pwq. As this function is called only from CPU + * hotplug callbacks and applying a new attrs is wrapped with + * get/put_online_cpus(), @wq->unbound_attrs couldn't have changed + * inbetween. + */ + mutex_lock(&wq->mutex); + old_pwq = numa_pwq_tbl_install(wq, node, pwq); + goto out_unlock; + +use_dfl_pwq: + spin_lock_irq(&wq->dfl_pwq->pool->lock); + get_pwq(wq->dfl_pwq); + spin_unlock_irq(&wq->dfl_pwq->pool->lock); + old_pwq = numa_pwq_tbl_install(wq, node, wq->dfl_pwq); +out_unlock: + mutex_unlock(&wq->mutex); + put_pwq_unlocked(old_pwq); +} + +static int alloc_and_link_pwqs(struct workqueue_struct *wq) +{ + bool highpri = wq->flags & WQ_HIGHPRI; + int cpu; + + if (!(wq->flags & WQ_UNBOUND)) { + wq->cpu_pwqs = alloc_percpu(struct pool_workqueue); + if (!wq->cpu_pwqs) + return -ENOMEM; + + for_each_possible_cpu(cpu) { + struct pool_workqueue *pwq = + per_cpu_ptr(wq->cpu_pwqs, cpu); + struct worker_pool *cpu_pools = + per_cpu(cpu_worker_pools, cpu); + + init_pwq(pwq, wq, &cpu_pools[highpri]); + + mutex_lock(&wq->mutex); + link_pwq(pwq); + mutex_unlock(&wq->mutex); + } + return 0; + } else { + return apply_workqueue_attrs(wq, unbound_std_wq_attrs[highpri]); } } @@ -3232,30 +4080,28 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, struct lock_class_key *key, const char *lock_name, ...) { - va_list args, args1; + size_t tbl_size = 0; + va_list args; struct workqueue_struct *wq; - unsigned int cpu; - size_t namelen; + struct pool_workqueue *pwq; - /* determine namelen, allocate wq and format name */ - va_start(args, lock_name); - va_copy(args1, args); - namelen = vsnprintf(NULL, 0, fmt, args) + 1; + /* allocate wq and format name */ + if (flags & WQ_UNBOUND) + tbl_size = wq_numa_tbl_len * sizeof(wq->numa_pwq_tbl[0]); - wq = kzalloc(sizeof(*wq) + namelen, GFP_KERNEL); + wq = kzalloc(sizeof(*wq) + tbl_size, GFP_KERNEL); if (!wq) - goto err; + return NULL; - vsnprintf(wq->name, namelen, fmt, args1); - va_end(args); - va_end(args1); + if (flags & WQ_UNBOUND) { + wq->unbound_attrs = alloc_workqueue_attrs(GFP_KERNEL); + if (!wq->unbound_attrs) + goto err_free_wq; + } - /* - * Workqueues which may be used during memory reclaim should - * have a rescuer to guarantee forward progress. - */ - if (flags & WQ_MEM_RECLAIM) - flags |= WQ_RESCUER; + va_start(args, lock_name); + vsnprintf(wq->name, sizeof(wq->name), fmt, args); + va_end(args); max_active = max_active ?: WQ_DFL_ACTIVE; max_active = wq_clamp_max_active(max_active, flags, wq->name); @@ -3263,72 +4109,70 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, /* init wq */ wq->flags = flags; wq->saved_max_active = max_active; - mutex_init(&wq->flush_mutex); - atomic_set(&wq->nr_cwqs_to_flush, 0); + mutex_init(&wq->mutex); + atomic_set(&wq->nr_pwqs_to_flush, 0); + INIT_LIST_HEAD(&wq->pwqs); INIT_LIST_HEAD(&wq->flusher_queue); INIT_LIST_HEAD(&wq->flusher_overflow); + INIT_LIST_HEAD(&wq->maydays); lockdep_init_map(&wq->lockdep_map, lock_name, key, 0); INIT_LIST_HEAD(&wq->list); - if (alloc_cwqs(wq) < 0) - goto err; + if (alloc_and_link_pwqs(wq) < 0) + goto err_free_wq; - for_each_cwq_cpu(cpu, wq) { - struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); - struct global_cwq *gcwq = get_gcwq(cpu); - int pool_idx = (bool)(flags & WQ_HIGHPRI); - - BUG_ON((unsigned long)cwq & WORK_STRUCT_FLAG_MASK); - cwq->pool = &gcwq->pools[pool_idx]; - cwq->wq = wq; - cwq->flush_color = -1; - cwq->max_active = max_active; - INIT_LIST_HEAD(&cwq->delayed_works); - } - - if (flags & WQ_RESCUER) { + /* + * Workqueues which may be used during memory reclaim should + * have a rescuer to guarantee forward progress. + */ + if (flags & WQ_MEM_RECLAIM) { struct worker *rescuer; - if (!alloc_mayday_mask(&wq->mayday_mask, GFP_KERNEL)) - goto err; - - wq->rescuer = rescuer = alloc_worker(); + rescuer = alloc_worker(); if (!rescuer) - goto err; + goto err_destroy; - rescuer->task = kthread_create(rescuer_thread, wq, "%s", + rescuer->rescue_wq = wq; + rescuer->task = kthread_create(rescuer_thread, rescuer, "%s", wq->name); - if (IS_ERR(rescuer->task)) - goto err; + if (IS_ERR(rescuer->task)) { + kfree(rescuer); + goto err_destroy; + } - rescuer->task->flags |= PF_THREAD_BOUND; + wq->rescuer = rescuer; + rescuer->task->flags |= PF_NO_SETAFFINITY; wake_up_process(rescuer->task); } + if ((wq->flags & WQ_SYSFS) && workqueue_sysfs_register(wq)) + goto err_destroy; + /* - * workqueue_lock protects global freeze state and workqueues - * list. Grab it, set max_active accordingly and add the new - * workqueue to workqueues list. + * wq_pool_mutex protects global freeze state and workqueues list. + * Grab it, adjust max_active and add the new @wq to workqueues + * list. */ - spin_lock(&workqueue_lock); + mutex_lock(&wq_pool_mutex); - if (workqueue_freezing && wq->flags & WQ_FREEZABLE) - for_each_cwq_cpu(cpu, wq) - get_cwq(cpu, wq)->max_active = 0; + mutex_lock(&wq->mutex); + for_each_pwq(pwq, wq) + pwq_adjust_max_active(pwq); + mutex_unlock(&wq->mutex); list_add(&wq->list, &workqueues); - spin_unlock(&workqueue_lock); + mutex_unlock(&wq_pool_mutex); return wq; -err: - if (wq) { - free_cwqs(wq); - free_mayday_mask(wq->mayday_mask); - kfree(wq->rescuer); - kfree(wq); - } + +err_free_wq: + free_workqueue_attrs(wq->unbound_attrs); + kfree(wq); + return NULL; +err_destroy: + destroy_workqueue(wq); return NULL; } EXPORT_SYMBOL_GPL(__alloc_workqueue_key); @@ -3341,60 +4185,78 @@ EXPORT_SYMBOL_GPL(__alloc_workqueue_key); */ void destroy_workqueue(struct workqueue_struct *wq) { - unsigned int cpu; + struct pool_workqueue *pwq; + int node; /* drain it before proceeding with destruction */ drain_workqueue(wq); + /* sanity checks */ + mutex_lock(&wq->mutex); + for_each_pwq(pwq, wq) { + int i; + + for (i = 0; i < WORK_NR_COLORS; i++) { + if (WARN_ON(pwq->nr_in_flight[i])) { + mutex_unlock(&wq->mutex); + return; + } + } + + if (WARN_ON((pwq != wq->dfl_pwq) && (pwq->refcnt > 1)) || + WARN_ON(pwq->nr_active) || + WARN_ON(!list_empty(&pwq->delayed_works))) { + mutex_unlock(&wq->mutex); + return; + } + } + mutex_unlock(&wq->mutex); + /* * wq list is used to freeze wq, remove from list after * flushing is complete in case freeze races us. */ - spin_lock(&workqueue_lock); - list_del(&wq->list); - spin_unlock(&workqueue_lock); + mutex_lock(&wq_pool_mutex); + list_del_init(&wq->list); + mutex_unlock(&wq_pool_mutex); - /* sanity check */ - for_each_cwq_cpu(cpu, wq) { - struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); - int i; + workqueue_sysfs_unregister(wq); - for (i = 0; i < WORK_NR_COLORS; i++) - BUG_ON(cwq->nr_in_flight[i]); - BUG_ON(cwq->nr_active); - BUG_ON(!list_empty(&cwq->delayed_works)); - } - - if (wq->flags & WQ_RESCUER) { + if (wq->rescuer) { kthread_stop(wq->rescuer->task); - free_mayday_mask(wq->mayday_mask); kfree(wq->rescuer); + wq->rescuer = NULL; } - free_cwqs(wq); - kfree(wq); -} -EXPORT_SYMBOL_GPL(destroy_workqueue); - -/** - * cwq_set_max_active - adjust max_active of a cwq - * @cwq: target cpu_workqueue_struct - * @max_active: new max_active value. - * - * Set @cwq->max_active to @max_active and activate delayed works if - * increased. - * - * CONTEXT: - * spin_lock_irq(gcwq->lock). - */ -static void cwq_set_max_active(struct cpu_workqueue_struct *cwq, int max_active) -{ - cwq->max_active = max_active; + if (!(wq->flags & WQ_UNBOUND)) { + /* + * The base ref is never dropped on per-cpu pwqs. Directly + * free the pwqs and wq. + */ + free_percpu(wq->cpu_pwqs); + kfree(wq); + } else { + /* + * We're the sole accessor of @wq at this point. Directly + * access numa_pwq_tbl[] and dfl_pwq to put the base refs. + * @wq will be freed when the last pwq is released. + */ + for_each_node(node) { + pwq = rcu_access_pointer(wq->numa_pwq_tbl[node]); + RCU_INIT_POINTER(wq->numa_pwq_tbl[node], NULL); + put_pwq_unlocked(pwq); + } - while (!list_empty(&cwq->delayed_works) && - cwq->nr_active < cwq->max_active) - cwq_activate_first_delayed(cwq); + /* + * Put dfl_pwq. @wq may be freed any time after dfl_pwq is + * put. Don't access it afterwards. + */ + pwq = wq->dfl_pwq; + wq->dfl_pwq = NULL; + put_pwq_unlocked(pwq); + } } +EXPORT_SYMBOL_GPL(destroy_workqueue); /** * workqueue_set_max_active - adjust max_active of a workqueue @@ -3408,29 +4270,37 @@ static void cwq_set_max_active(struct cpu_workqueue_struct *cwq, int max_active) */ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active) { - unsigned int cpu; + struct pool_workqueue *pwq; + + /* disallow meddling with max_active for ordered workqueues */ + if (WARN_ON(wq->flags & __WQ_ORDERED)) + return; max_active = wq_clamp_max_active(max_active, wq->flags, wq->name); - spin_lock(&workqueue_lock); + mutex_lock(&wq->mutex); wq->saved_max_active = max_active; - for_each_cwq_cpu(cpu, wq) { - struct global_cwq *gcwq = get_gcwq(cpu); - - spin_lock_irq(&gcwq->lock); + for_each_pwq(pwq, wq) + pwq_adjust_max_active(pwq); - if (!(wq->flags & WQ_FREEZABLE) || - !(gcwq->flags & GCWQ_FREEZING)) - cwq_set_max_active(get_cwq(gcwq->cpu, wq), max_active); + mutex_unlock(&wq->mutex); +} +EXPORT_SYMBOL_GPL(workqueue_set_max_active); - spin_unlock_irq(&gcwq->lock); - } +/** + * current_is_workqueue_rescuer - is %current workqueue rescuer? + * + * Determine whether %current is a workqueue rescuer. Can be used from + * work functions to determine whether it's being run off the rescuer task. + */ +bool current_is_workqueue_rescuer(void) +{ + struct worker *worker = current_wq_worker(); - spin_unlock(&workqueue_lock); + return worker && worker->rescue_wq; } -EXPORT_SYMBOL_GPL(workqueue_set_max_active); /** * workqueue_congested - test whether a workqueue is congested @@ -3444,28 +4314,24 @@ EXPORT_SYMBOL_GPL(workqueue_set_max_active); * RETURNS: * %true if congested, %false otherwise. */ -bool workqueue_congested(unsigned int cpu, struct workqueue_struct *wq) +bool workqueue_congested(int cpu, struct workqueue_struct *wq) { - struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); + struct pool_workqueue *pwq; + bool ret; - return !list_empty(&cwq->delayed_works); -} -EXPORT_SYMBOL_GPL(workqueue_congested); + rcu_read_lock_sched(); -/** - * work_cpu - return the last known associated cpu for @work - * @work: the work of interest - * - * RETURNS: - * CPU number if @work was ever queued. WORK_CPU_NONE otherwise. - */ -unsigned int work_cpu(struct work_struct *work) -{ - struct global_cwq *gcwq = get_work_gcwq(work); + if (!(wq->flags & WQ_UNBOUND)) + pwq = per_cpu_ptr(wq->cpu_pwqs, cpu); + else + pwq = unbound_pwq_by_node(wq, cpu_to_node(cpu)); + + ret = !list_empty(&pwq->delayed_works); + rcu_read_unlock_sched(); - return gcwq ? gcwq->cpu : WORK_CPU_NONE; + return ret; } -EXPORT_SYMBOL_GPL(work_cpu); +EXPORT_SYMBOL_GPL(workqueue_congested); /** * work_busy - test whether a work is currently pending or running @@ -3474,118 +4340,277 @@ EXPORT_SYMBOL_GPL(work_cpu); * Test whether @work is currently pending or running. There is no * synchronization around this function and the test result is * unreliable and only useful as advisory hints or for debugging. - * Especially for reentrant wqs, the pending state might hide the - * running state. * * RETURNS: * OR'd bitmask of WORK_BUSY_* bits. */ unsigned int work_busy(struct work_struct *work) { - struct global_cwq *gcwq = get_work_gcwq(work); + struct worker_pool *pool; unsigned long flags; unsigned int ret = 0; - if (!gcwq) - return 0; - - spin_lock_irqsave(&gcwq->lock, flags); - if (work_pending(work)) ret |= WORK_BUSY_PENDING; - if (find_worker_executing_work(gcwq, work)) - ret |= WORK_BUSY_RUNNING; - spin_unlock_irqrestore(&gcwq->lock, flags); + local_irq_save(flags); + pool = get_work_pool(work); + if (pool) { + spin_lock(&pool->lock); + if (find_worker_executing_work(pool, work)) + ret |= WORK_BUSY_RUNNING; + spin_unlock(&pool->lock); + } + local_irq_restore(flags); return ret; } EXPORT_SYMBOL_GPL(work_busy); +/** + * set_worker_desc - set description for the current work item + * @fmt: printf-style format string + * @...: arguments for the format string + * + * This function can be called by a running work function to describe what + * the work item is about. If the worker task gets dumped, this + * information will be printed out together to help debugging. The + * description can be at most WORKER_DESC_LEN including the trailing '\0'. + */ +void set_worker_desc(const char *fmt, ...) +{ + struct worker *worker = current_wq_worker(); + va_list args; + + if (worker) { + va_start(args, fmt); + vsnprintf(worker->desc, sizeof(worker->desc), fmt, args); + va_end(args); + worker->desc_valid = true; + } +} + +/** + * print_worker_info - print out worker information and description + * @log_lvl: the log level to use when printing + * @task: target task + * + * If @task is a worker and currently executing a work item, print out the + * name of the workqueue being serviced and worker description set with + * set_worker_desc() by the currently executing work item. + * + * This function can be safely called on any task as long as the + * task_struct itself is accessible. While safe, this function isn't + * synchronized and may print out mixups or garbages of limited length. + */ +void print_worker_info(const char *log_lvl, struct task_struct *task) +{ + work_func_t *fn = NULL; + char name[WQ_NAME_LEN] = { }; + char desc[WORKER_DESC_LEN] = { }; + struct pool_workqueue *pwq = NULL; + struct workqueue_struct *wq = NULL; + bool desc_valid = false; + struct worker *worker; + + if (!(task->flags & PF_WQ_WORKER)) + return; + + /* + * This function is called without any synchronization and @task + * could be in any state. Be careful with dereferences. + */ + worker = probe_kthread_data(task); + + /* + * Carefully copy the associated workqueue's workfn and name. Keep + * the original last '\0' in case the original contains garbage. + */ + probe_kernel_read(&fn, &worker->current_func, sizeof(fn)); + probe_kernel_read(&pwq, &worker->current_pwq, sizeof(pwq)); + probe_kernel_read(&wq, &pwq->wq, sizeof(wq)); + probe_kernel_read(name, wq->name, sizeof(name) - 1); + + /* copy worker description */ + probe_kernel_read(&desc_valid, &worker->desc_valid, sizeof(desc_valid)); + if (desc_valid) + probe_kernel_read(desc, worker->desc, sizeof(desc) - 1); + + if (fn || name[0] || desc[0]) { + printk("%sWorkqueue: %s %pf", log_lvl, name, fn); + if (desc[0]) + pr_cont(" (%s)", desc); + pr_cont("\n"); + } +} + /* * CPU hotplug. * * There are two challenges in supporting CPU hotplug. Firstly, there - * are a lot of assumptions on strong associations among work, cwq and - * gcwq which make migrating pending and scheduled works very + * are a lot of assumptions on strong associations among work, pwq and + * pool which make migrating pending and scheduled works very * difficult to implement without impacting hot paths. Secondly, - * gcwqs serve mix of short, long and very long running works making + * worker pools serve mix of short, long and very long running works making * blocked draining impractical. * - * This is solved by allowing a gcwq to be disassociated from the CPU + * This is solved by allowing the pools to be disassociated from the CPU * running as an unbound one and allowing it to be reattached later if the * cpu comes back online. */ -/* claim manager positions of all pools */ -static void gcwq_claim_assoc_and_lock(struct global_cwq *gcwq) +static void wq_unbind_fn(struct work_struct *work) { + int cpu = smp_processor_id(); struct worker_pool *pool; + struct worker *worker; + int wi; - for_each_worker_pool(pool, gcwq) - mutex_lock_nested(&pool->assoc_mutex, pool - gcwq->pools); - spin_lock_irq(&gcwq->lock); -} + for_each_cpu_worker_pool(pool, cpu) { + WARN_ON_ONCE(cpu != smp_processor_id()); -/* release manager positions */ -static void gcwq_release_assoc_and_unlock(struct global_cwq *gcwq) -{ - struct worker_pool *pool; + mutex_lock(&pool->manager_mutex); + spin_lock_irq(&pool->lock); + + /* + * We've blocked all manager operations. Make all workers + * unbound and set DISASSOCIATED. Before this, all workers + * except for the ones which are still executing works from + * before the last CPU down must be on the cpu. After + * this, they may become diasporas. + */ + for_each_pool_worker(worker, wi, pool) + worker->flags |= WORKER_UNBOUND; + + pool->flags |= POOL_DISASSOCIATED; + + spin_unlock_irq(&pool->lock); + mutex_unlock(&pool->manager_mutex); + + /* + * Call schedule() so that we cross rq->lock and thus can + * guarantee sched callbacks see the %WORKER_UNBOUND flag. + * This is necessary as scheduler callbacks may be invoked + * from other cpus. + */ + schedule(); + + /* + * Sched callbacks are disabled now. Zap nr_running. + * After this, nr_running stays zero and need_more_worker() + * and keep_working() are always true as long as the + * worklist is not empty. This pool now behaves as an + * unbound (in terms of concurrency management) pool which + * are served by workers tied to the pool. + */ + atomic_set(&pool->nr_running, 0); - spin_unlock_irq(&gcwq->lock); - for_each_worker_pool(pool, gcwq) - mutex_unlock(&pool->assoc_mutex); + /* + * With concurrency management just turned off, a busy + * worker blocking could lead to lengthy stalls. Kick off + * unbound chain execution of currently pending work items. + */ + spin_lock_irq(&pool->lock); + wake_up_worker(pool); + spin_unlock_irq(&pool->lock); + } } -static void gcwq_unbind_fn(struct work_struct *work) +/** + * rebind_workers - rebind all workers of a pool to the associated CPU + * @pool: pool of interest + * + * @pool->cpu is coming online. Rebind all workers to the CPU. + */ +static void rebind_workers(struct worker_pool *pool) { - struct global_cwq *gcwq = get_gcwq(smp_processor_id()); - struct worker_pool *pool; struct worker *worker; - struct hlist_node *pos; - int i; - - BUG_ON(gcwq->cpu != smp_processor_id()); + int wi; - gcwq_claim_assoc_and_lock(gcwq); + lockdep_assert_held(&pool->manager_mutex); /* - * We've claimed all manager positions. Make all workers unbound - * and set DISASSOCIATED. Before this, all workers except for the - * ones which are still executing works from before the last CPU - * down must be on the cpu. After this, they may become diasporas. + * Restore CPU affinity of all workers. As all idle workers should + * be on the run-queue of the associated CPU before any local + * wake-ups for concurrency management happen, restore CPU affinty + * of all workers first and then clear UNBOUND. As we're called + * from CPU_ONLINE, the following shouldn't fail. */ - for_each_worker_pool(pool, gcwq) - list_for_each_entry(worker, &pool->idle_list, entry) - worker->flags |= WORKER_UNBOUND; + for_each_pool_worker(worker, wi, pool) + WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, + pool->attrs->cpumask) < 0); - for_each_busy_worker(worker, i, pos, gcwq) - worker->flags |= WORKER_UNBOUND; + spin_lock_irq(&pool->lock); - gcwq->flags |= GCWQ_DISASSOCIATED; + for_each_pool_worker(worker, wi, pool) { + unsigned int worker_flags = worker->flags; - gcwq_release_assoc_and_unlock(gcwq); + /* + * A bound idle worker should actually be on the runqueue + * of the associated CPU for local wake-ups targeting it to + * work. Kick all idle workers so that they migrate to the + * associated CPU. Doing this in the same loop as + * replacing UNBOUND with REBOUND is safe as no worker will + * be bound before @pool->lock is released. + */ + if (worker_flags & WORKER_IDLE) + wake_up_process(worker->task); - /* - * Call schedule() so that we cross rq->lock and thus can guarantee - * sched callbacks see the %WORKER_UNBOUND flag. This is necessary - * as scheduler callbacks may be invoked from other cpus. - */ - schedule(); + /* + * We want to clear UNBOUND but can't directly call + * worker_clr_flags() or adjust nr_running. Atomically + * replace UNBOUND with another NOT_RUNNING flag REBOUND. + * @worker will clear REBOUND using worker_clr_flags() when + * it initiates the next execution cycle thus restoring + * concurrency management. Note that when or whether + * @worker clears REBOUND doesn't affect correctness. + * + * ACCESS_ONCE() is necessary because @worker->flags may be + * tested without holding any lock in + * wq_worker_waking_up(). Without it, NOT_RUNNING test may + * fail incorrectly leading to premature concurrency + * management operations. + */ + WARN_ON_ONCE(!(worker_flags & WORKER_UNBOUND)); + worker_flags |= WORKER_REBOUND; + worker_flags &= ~WORKER_UNBOUND; + ACCESS_ONCE(worker->flags) = worker_flags; + } - /* - * Sched callbacks are disabled now. Zap nr_running. After this, - * nr_running stays zero and need_more_worker() and keep_working() - * are always true as long as the worklist is not empty. @gcwq now - * behaves as unbound (in terms of concurrency management) gcwq - * which is served by workers tied to the CPU. - * - * On return from this function, the current worker would trigger - * unbound chain execution of pending work items if other workers - * didn't already. - */ - for_each_worker_pool(pool, gcwq) - atomic_set(get_pool_nr_running(pool), 0); + spin_unlock_irq(&pool->lock); +} + +/** + * restore_unbound_workers_cpumask - restore cpumask of unbound workers + * @pool: unbound pool of interest + * @cpu: the CPU which is coming up + * + * An unbound pool may end up with a cpumask which doesn't have any online + * CPUs. When a worker of such pool get scheduled, the scheduler resets + * its cpus_allowed. If @cpu is in @pool's cpumask which didn't have any + * online CPU before, cpus_allowed of all its workers should be restored. + */ +static void restore_unbound_workers_cpumask(struct worker_pool *pool, int cpu) +{ + static cpumask_t cpumask; + struct worker *worker; + int wi; + + lockdep_assert_held(&pool->manager_mutex); + + /* is @cpu allowed for @pool? */ + if (!cpumask_test_cpu(cpu, pool->attrs->cpumask)) + return; + + /* is @cpu the only online CPU? */ + cpumask_and(&cpumask, pool->attrs->cpumask, cpu_online_mask); + if (cpumask_weight(&cpumask) != 1) + return; + + /* as we're called from CPU_ONLINE, the following shouldn't fail */ + for_each_pool_worker(worker, wi, pool) + WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, + pool->attrs->cpumask) < 0); } /* @@ -3596,34 +4621,46 @@ static int __cpuinit workqueue_cpu_up_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { - unsigned int cpu = (unsigned long)hcpu; - struct global_cwq *gcwq = get_gcwq(cpu); + int cpu = (unsigned long)hcpu; struct worker_pool *pool; + struct workqueue_struct *wq; + int pi; switch (action & ~CPU_TASKS_FROZEN) { case CPU_UP_PREPARE: - for_each_worker_pool(pool, gcwq) { - struct worker *worker; - + for_each_cpu_worker_pool(pool, cpu) { if (pool->nr_workers) continue; - - worker = create_worker(pool); - if (!worker) + if (create_and_start_worker(pool) < 0) return NOTIFY_BAD; - - spin_lock_irq(&gcwq->lock); - start_worker(worker); - spin_unlock_irq(&gcwq->lock); } break; case CPU_DOWN_FAILED: case CPU_ONLINE: - gcwq_claim_assoc_and_lock(gcwq); - gcwq->flags &= ~GCWQ_DISASSOCIATED; - rebind_workers(gcwq); - gcwq_release_assoc_and_unlock(gcwq); + mutex_lock(&wq_pool_mutex); + + for_each_pool(pool, pi) { + mutex_lock(&pool->manager_mutex); + + if (pool->cpu == cpu) { + spin_lock_irq(&pool->lock); + pool->flags &= ~POOL_DISASSOCIATED; + spin_unlock_irq(&pool->lock); + + rebind_workers(pool); + } else if (pool->cpu < 0) { + restore_unbound_workers_cpumask(pool, cpu); + } + + mutex_unlock(&pool->manager_mutex); + } + + /* update NUMA affinity of unbound workqueues */ + list_for_each_entry(wq, &workqueues, list) + wq_update_unbound_numa(wq, cpu, true); + + mutex_unlock(&wq_pool_mutex); break; } return NOTIFY_OK; @@ -3637,14 +4674,23 @@ static int __cpuinit workqueue_cpu_down_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { - unsigned int cpu = (unsigned long)hcpu; + int cpu = (unsigned long)hcpu; struct work_struct unbind_work; + struct workqueue_struct *wq; switch (action & ~CPU_TASKS_FROZEN) { case CPU_DOWN_PREPARE: - /* unbinding should happen on the local CPU */ - INIT_WORK_ONSTACK(&unbind_work, gcwq_unbind_fn); + /* unbinding per-cpu workers should happen on the local CPU */ + INIT_WORK_ONSTACK(&unbind_work, wq_unbind_fn); queue_work_on(cpu, system_highpri_wq, &unbind_work); + + /* update NUMA affinity of unbound workqueues */ + mutex_lock(&wq_pool_mutex); + list_for_each_entry(wq, &workqueues, list) + wq_update_unbound_numa(wq, cpu, false); + mutex_unlock(&wq_pool_mutex); + + /* wait for per-cpu unbinding to finish */ flush_work(&unbind_work); break; } @@ -3677,7 +4723,7 @@ static void work_for_cpu_fn(struct work_struct *work) * It is up to the caller to ensure that the cpu doesn't go offline. * The caller must not hold any locks which would prevent @fn from completing. */ -long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg) +long work_on_cpu(int cpu, long (*fn)(void *), void *arg) { struct work_for_cpu wfc = { .fn = fn, .arg = arg }; @@ -3695,41 +4741,40 @@ EXPORT_SYMBOL_GPL(work_on_cpu); * freeze_workqueues_begin - begin freezing workqueues * * Start freezing workqueues. After this function returns, all freezable - * workqueues will queue new works to their frozen_works list instead of - * gcwq->worklist. + * workqueues will queue new works to their delayed_works list instead of + * pool->worklist. * * CONTEXT: - * Grabs and releases workqueue_lock and gcwq->lock's. + * Grabs and releases wq_pool_mutex, wq->mutex and pool->lock's. */ void freeze_workqueues_begin(void) { - unsigned int cpu; + struct worker_pool *pool; + struct workqueue_struct *wq; + struct pool_workqueue *pwq; + int pi; - spin_lock(&workqueue_lock); + mutex_lock(&wq_pool_mutex); - BUG_ON(workqueue_freezing); + WARN_ON_ONCE(workqueue_freezing); workqueue_freezing = true; - for_each_gcwq_cpu(cpu) { - struct global_cwq *gcwq = get_gcwq(cpu); - struct workqueue_struct *wq; - - spin_lock_irq(&gcwq->lock); - - BUG_ON(gcwq->flags & GCWQ_FREEZING); - gcwq->flags |= GCWQ_FREEZING; - - list_for_each_entry(wq, &workqueues, list) { - struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); - - if (cwq && wq->flags & WQ_FREEZABLE) - cwq->max_active = 0; - } + /* set FREEZING */ + for_each_pool(pool, pi) { + spin_lock_irq(&pool->lock); + WARN_ON_ONCE(pool->flags & POOL_FREEZING); + pool->flags |= POOL_FREEZING; + spin_unlock_irq(&pool->lock); + } - spin_unlock_irq(&gcwq->lock); + list_for_each_entry(wq, &workqueues, list) { + mutex_lock(&wq->mutex); + for_each_pwq(pwq, wq) + pwq_adjust_max_active(pwq); + mutex_unlock(&wq->mutex); } - spin_unlock(&workqueue_lock); + mutex_unlock(&wq_pool_mutex); } /** @@ -3739,7 +4784,7 @@ void freeze_workqueues_begin(void) * between freeze_workqueues_begin() and thaw_workqueues(). * * CONTEXT: - * Grabs and releases workqueue_lock. + * Grabs and releases wq_pool_mutex. * * RETURNS: * %true if some freezable workqueues are still busy. %false if freezing @@ -3747,34 +4792,34 @@ void freeze_workqueues_begin(void) */ bool freeze_workqueues_busy(void) { - unsigned int cpu; bool busy = false; + struct workqueue_struct *wq; + struct pool_workqueue *pwq; - spin_lock(&workqueue_lock); + mutex_lock(&wq_pool_mutex); - BUG_ON(!workqueue_freezing); + WARN_ON_ONCE(!workqueue_freezing); - for_each_gcwq_cpu(cpu) { - struct workqueue_struct *wq; + list_for_each_entry(wq, &workqueues, list) { + if (!(wq->flags & WQ_FREEZABLE)) + continue; /* * nr_active is monotonically decreasing. It's safe * to peek without lock. */ - list_for_each_entry(wq, &workqueues, list) { - struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); - - if (!cwq || !(wq->flags & WQ_FREEZABLE)) - continue; - - BUG_ON(cwq->nr_active < 0); - if (cwq->nr_active) { + rcu_read_lock_sched(); + for_each_pwq(pwq, wq) { + WARN_ON_ONCE(pwq->nr_active < 0); + if (pwq->nr_active) { busy = true; + rcu_read_unlock_sched(); goto out_unlock; } } + rcu_read_unlock_sched(); } out_unlock: - spin_unlock(&workqueue_lock); + mutex_unlock(&wq_pool_mutex); return busy; } @@ -3782,110 +4827,144 @@ out_unlock: * thaw_workqueues - thaw workqueues * * Thaw workqueues. Normal queueing is restored and all collected - * frozen works are transferred to their respective gcwq worklists. + * frozen works are transferred to their respective pool worklists. * * CONTEXT: - * Grabs and releases workqueue_lock and gcwq->lock's. + * Grabs and releases wq_pool_mutex, wq->mutex and pool->lock's. */ void thaw_workqueues(void) { - unsigned int cpu; + struct workqueue_struct *wq; + struct pool_workqueue *pwq; + struct worker_pool *pool; + int pi; - spin_lock(&workqueue_lock); + mutex_lock(&wq_pool_mutex); if (!workqueue_freezing) goto out_unlock; - for_each_gcwq_cpu(cpu) { - struct global_cwq *gcwq = get_gcwq(cpu); - struct worker_pool *pool; - struct workqueue_struct *wq; + /* clear FREEZING */ + for_each_pool(pool, pi) { + spin_lock_irq(&pool->lock); + WARN_ON_ONCE(!(pool->flags & POOL_FREEZING)); + pool->flags &= ~POOL_FREEZING; + spin_unlock_irq(&pool->lock); + } - spin_lock_irq(&gcwq->lock); + /* restore max_active and repopulate worklist */ + list_for_each_entry(wq, &workqueues, list) { + mutex_lock(&wq->mutex); + for_each_pwq(pwq, wq) + pwq_adjust_max_active(pwq); + mutex_unlock(&wq->mutex); + } - BUG_ON(!(gcwq->flags & GCWQ_FREEZING)); - gcwq->flags &= ~GCWQ_FREEZING; + workqueue_freezing = false; +out_unlock: + mutex_unlock(&wq_pool_mutex); +} +#endif /* CONFIG_FREEZER */ - list_for_each_entry(wq, &workqueues, list) { - struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); +static void __init wq_numa_init(void) +{ + cpumask_var_t *tbl; + int node, cpu; - if (!cwq || !(wq->flags & WQ_FREEZABLE)) - continue; + /* determine NUMA pwq table len - highest node id + 1 */ + for_each_node(node) + wq_numa_tbl_len = max(wq_numa_tbl_len, node + 1); - /* restore max_active and repopulate worklist */ - cwq_set_max_active(cwq, wq->saved_max_active); - } + if (num_possible_nodes() <= 1) + return; - for_each_worker_pool(pool, gcwq) - wake_up_worker(pool); + if (wq_disable_numa) { + pr_info("workqueue: NUMA affinity support disabled\n"); + return; + } + + wq_update_unbound_numa_attrs_buf = alloc_workqueue_attrs(GFP_KERNEL); + BUG_ON(!wq_update_unbound_numa_attrs_buf); - spin_unlock_irq(&gcwq->lock); + /* + * We want masks of possible CPUs of each node which isn't readily + * available. Build one from cpu_to_node() which should have been + * fully initialized by now. + */ + tbl = kzalloc(wq_numa_tbl_len * sizeof(tbl[0]), GFP_KERNEL); + BUG_ON(!tbl); + + for_each_node(node) + BUG_ON(!alloc_cpumask_var_node(&tbl[node], GFP_KERNEL, node)); + + for_each_possible_cpu(cpu) { + node = cpu_to_node(cpu); + if (WARN_ON(node == NUMA_NO_NODE)) { + pr_warn("workqueue: NUMA node mapping not available for cpu%d, disabling NUMA support\n", cpu); + /* happens iff arch is bonkers, let's just proceed */ + return; + } + cpumask_set_cpu(cpu, tbl[node]); } - workqueue_freezing = false; -out_unlock: - spin_unlock(&workqueue_lock); + wq_numa_possible_cpumask = tbl; + wq_numa_enabled = true; } -#endif /* CONFIG_FREEZER */ static int __init init_workqueues(void) { - unsigned int cpu; - int i; - - /* make sure we have enough bits for OFFQ CPU number */ - BUILD_BUG_ON((1LU << (BITS_PER_LONG - WORK_OFFQ_CPU_SHIFT)) < - WORK_CPU_LAST); - - cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP); - hotcpu_notifier(workqueue_cpu_down_callback, CPU_PRI_WORKQUEUE_DOWN); + int std_nice[NR_STD_WORKER_POOLS] = { 0, HIGHPRI_NICE_LEVEL }; + int i, cpu; - /* initialize gcwqs */ - for_each_gcwq_cpu(cpu) { - struct global_cwq *gcwq = get_gcwq(cpu); - struct worker_pool *pool; + /* make sure we have enough bits for OFFQ pool ID */ + BUILD_BUG_ON((1LU << (BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT)) < + WORK_CPU_END * NR_STD_WORKER_POOLS); - spin_lock_init(&gcwq->lock); - gcwq->cpu = cpu; - gcwq->flags |= GCWQ_DISASSOCIATED; + WARN_ON(__alignof__(struct pool_workqueue) < __alignof__(long long)); - for (i = 0; i < BUSY_WORKER_HASH_SIZE; i++) - INIT_HLIST_HEAD(&gcwq->busy_hash[i]); + pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC); - for_each_worker_pool(pool, gcwq) { - pool->gcwq = gcwq; - INIT_LIST_HEAD(&pool->worklist); - INIT_LIST_HEAD(&pool->idle_list); + cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP); + hotcpu_notifier(workqueue_cpu_down_callback, CPU_PRI_WORKQUEUE_DOWN); - init_timer_deferrable(&pool->idle_timer); - pool->idle_timer.function = idle_worker_timeout; - pool->idle_timer.data = (unsigned long)pool; + wq_numa_init(); - setup_timer(&pool->mayday_timer, gcwq_mayday_timeout, - (unsigned long)pool); + /* initialize CPU pools */ + for_each_possible_cpu(cpu) { + struct worker_pool *pool; - mutex_init(&pool->assoc_mutex); - ida_init(&pool->worker_ida); + i = 0; + for_each_cpu_worker_pool(pool, cpu) { + BUG_ON(init_worker_pool(pool)); + pool->cpu = cpu; + cpumask_copy(pool->attrs->cpumask, cpumask_of(cpu)); + pool->attrs->nice = std_nice[i++]; + pool->node = cpu_to_node(cpu); + + /* alloc pool ID */ + mutex_lock(&wq_pool_mutex); + BUG_ON(worker_pool_assign_id(pool)); + mutex_unlock(&wq_pool_mutex); } } /* create the initial worker */ - for_each_online_gcwq_cpu(cpu) { - struct global_cwq *gcwq = get_gcwq(cpu); + for_each_online_cpu(cpu) { struct worker_pool *pool; - if (cpu != WORK_CPU_UNBOUND) - gcwq->flags &= ~GCWQ_DISASSOCIATED; + for_each_cpu_worker_pool(pool, cpu) { + pool->flags &= ~POOL_DISASSOCIATED; + BUG_ON(create_and_start_worker(pool) < 0); + } + } - for_each_worker_pool(pool, gcwq) { - struct worker *worker; + /* create default unbound wq attrs */ + for (i = 0; i < NR_STD_WORKER_POOLS; i++) { + struct workqueue_attrs *attrs; - worker = create_worker(pool); - BUG_ON(!worker); - spin_lock_irq(&gcwq->lock); - start_worker(worker); - spin_unlock_irq(&gcwq->lock); - } + BUG_ON(!(attrs = alloc_workqueue_attrs(GFP_KERNEL))); + attrs->nice = std_nice[i]; + unbound_std_wq_attrs[i] = attrs; } system_wq = alloc_workqueue("events", 0, 0); diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h new file mode 100644 index 000000000000..ad83c96b2ece --- /dev/null +++ b/kernel/workqueue_internal.h @@ -0,0 +1,72 @@ +/* + * kernel/workqueue_internal.h + * + * Workqueue internal header file. Only to be included by workqueue and + * core kernel subsystems. + */ +#ifndef _KERNEL_WORKQUEUE_INTERNAL_H +#define _KERNEL_WORKQUEUE_INTERNAL_H + +#include <linux/workqueue.h> +#include <linux/kthread.h> + +struct worker_pool; + +/* + * The poor guys doing the actual heavy lifting. All on-duty workers are + * either serving the manager role, on idle list or on busy hash. For + * details on the locking annotation (L, I, X...), refer to workqueue.c. + * + * Only to be used in workqueue and async. + */ +struct worker { + /* on idle list while idle, on busy hash table while busy */ + union { + struct list_head entry; /* L: while idle */ + struct hlist_node hentry; /* L: while busy */ + }; + + struct work_struct *current_work; /* L: work being processed */ + work_func_t current_func; /* L: current_work's fn */ + struct pool_workqueue *current_pwq; /* L: current_work's pwq */ + bool desc_valid; /* ->desc is valid */ + struct list_head scheduled; /* L: scheduled works */ + + /* 64 bytes boundary on 64bit, 32 on 32bit */ + + struct task_struct *task; /* I: worker task */ + struct worker_pool *pool; /* I: the associated pool */ + /* L: for rescuers */ + + unsigned long last_active; /* L: last active timestamp */ + unsigned int flags; /* X: flags */ + int id; /* I: worker id */ + + /* + * Opaque string set with work_set_desc(). Printed out with task + * dump for debugging - WARN, BUG, panic or sysrq. + */ + char desc[WORKER_DESC_LEN]; + + /* used only by rescuers to point to the target workqueue */ + struct workqueue_struct *rescue_wq; /* I: the workqueue to rescue */ +}; + +/** + * current_wq_worker - return struct worker if %current is a workqueue worker + */ +static inline struct worker *current_wq_worker(void) +{ + if (current->flags & PF_WQ_WORKER) + return kthread_data(current); + return NULL; +} + +/* + * Scheduler hooks for concurrency managed workqueue. Only to be used from + * sched.c and workqueue.c. + */ +void wq_worker_waking_up(struct task_struct *task, int cpu); +struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu); + +#endif /* _KERNEL_WORKQUEUE_INTERNAL_H */ diff --git a/kernel/workqueue_sched.h b/kernel/workqueue_sched.h deleted file mode 100644 index 2d10fc98dc79..000000000000 --- a/kernel/workqueue_sched.h +++ /dev/null @@ -1,9 +0,0 @@ -/* - * kernel/workqueue_sched.h - * - * Scheduler hooks for concurrency managed workqueue. Only to be - * included from sched.c and workqueue.c. - */ -void wq_worker_waking_up(struct task_struct *task, unsigned int cpu); -struct task_struct *wq_worker_sleeping(struct task_struct *task, - unsigned int cpu); |