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2009-10-12futex: Move exit_pi_state() call to release_mm()Thomas Gleixner
commit 322a2c100a8998158445599ea437fb556aa95b11 upstream. exit_pi_state() is called from do_exit() but not from do_execve(). Move it to release_mm() so it gets called from do_execve() as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <new-submission> Cc: Anirban Sinha <ani@anirban.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-08headers: mnt_namespace.h reduxAlexey Dobriyan
Fix various silly problems wrt mnt_namespace.h: - exit_mnt_ns() isn't used, remove it - done that, sched.h and nsproxy.h inclusions aren't needed - mount.h inclusion was need for vfsmount_lock, but no longer - remove mnt_namespace.h inclusion from files which don't use anything from mnt_namespace.h Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-19ptrace: wait_task_zombie: do not account traced sub-threadsOleg Nesterov
The bug is ancient. If we trace the sub-thread of our natural child and this sub-thread exits, we update parent->signal->cxxx fields. But we should not do this until the whole thread-group exits, otherwise we account this thread (and all other live threads) twice. Add the task_detached() check. No need to check thread_group_empty(), wait_consider_task()->delay_group_leader() already did this. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Roland McGrath <roland@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Vitaly Mayatskikh <vmayatsk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18mm: exit.c reorder wait_opts to remove padding on 64 bit buildsRichard Kennedy
Reorder struct wait_opts to remove 8 bytes of alignment padding on 64 bit builds. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18do_wait: fix the theoretical race with stop/trace/contOleg Nesterov
do_wait: current->state = TASK_INTERRUPTIBLE; read_lock(&tasklist_lock); ... search for the task to reap ... In theory, the ->state changing can leak into the critical section. Since the child can change its status under read_lock(tasklist) in parallel (finish_stop/ptrace_stop), we can miss the wakeup if __wake_up_parent() sees us in TASK_RUNNING state. Add the barrier. Also, use __set_current_state() to set TASK_RUNNING. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18do_wait: kill the old BUG_ON, use while_each_thread()Oleg Nesterov
do_wait() does BUG_ON(tsk->signal != current->signal), this looks like a raher obsolete check. At least, I don't think do_wait() is the best place to verify that all threads have the same ->signal. Remove it. Also, change the code to use while_each_thread(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18do_wait: simplify retval/tsk_result/notask_error messOleg Nesterov
Now that we don't pass &retval down to other helpers we can simplify the code more. - kill tsk_result, just use retval - add the "notask" label right after the main loop, and s/got end/goto notask/ after the fastpath pid check. This way we don't need to initialize retval before this check and the code becomes a bit more clean, if this pid has no attached tasks we should just skip the list search. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18introduce "struct wait_opts" to simplify do_wait() patchesOleg Nesterov
Introduce "struct wait_opts" which holds the parameters for misc helpers in do_wait() pathes. This adds 13 lines to kernel/exit.c, but saves 256 bytes from .o and imho makes the code much more readable. This patch temporary uglifies rusage/siginfo code a little bit, will be addressed by further cleanups. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18shift "ptrace implies WUNTRACED" from ptrace_do_wait() to wait_task_stopped()Oleg Nesterov
No functional changes, preparation for the next patch. ptrace_do_wait() adds WUNTRACED to options for wait_task_stopped() which should always accept the stopped tracee, even if do_wait() was called without WUNTRACED. Change wait_task_stopped() to check "ptrace || WUNTRACED" instead. This makes the code more explicit, and "int options" argument becomes const in do_wait() pathes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18wait_task_zombie: do not use thread_group_cputime()Oleg Nesterov
There is no reason for thread_group_cputime() in wait_task_zombie(), there must be no other threads. This call was previously needed to collect the per-cpu data which we do not have any longer. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Roland McGrath <roland@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Vitaly Mayatskikh <vmayatsk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18ptrace: wait_task_zombie: s/->parent/->real_parent/Oleg Nesterov
Change wait_task_zombie() to use ->real_parent instead of ->parent. We could even use current afaics, but ->real_parent is more clean. We know that the child is not ptrace_reparented() and thus they are equal. But we should avoid using task_struct->parent, we are going to remove it. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18ptrace: do not use task->ptrace directly in core kernelOleg Nesterov
No functional changes. - Nobody except ptrace.c & co should use ptrace flags directly, we have task_ptrace() for that. - No need to specially check PT_PTRACED, we must not have other PT_ bits set without PT_PTRACED. And no need to know this flag exists. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18ptrace: mm_need_new_owner: use ->real_parent to search in the siblingsOleg Nesterov
"Search in the siblings" should use ->real_parent, not ->parent. If the task is traced then ->parent == tracer, while the task's parent is always ->real_parent. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18allow_signal: kill the bogus ->mm check, add a note about CLONE_SIGHANDOleg Nesterov
allow_signal() checks ->mm == NULL. Not sure why. Perhaps to make sure current is the kernel thread. But this helper must not be used unless we are the kernel thread, kill this check. Also, document the fact that the CLONE_SIGHAND kthread must not use allow_signal(), unless the caller really wants to change the parent's ->sighand->action as well. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11Merge branch 'perfcounters-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (574 commits) perf_counter: Turn off by default perf_counter: Add counter->id to the throttle event perf_counter: Better align code perf_counter: Rename L2 to LL cache perf_counter: Standardize event names perf_counter: Rename enums perf_counter tools: Clean up u64 usage perf_counter: Rename perf_counter_limit sysctl perf_counter: More paranoia settings perf_counter: powerpc: Implement generalized cache events for POWER processors perf_counters: powerpc: Add support for POWER7 processors perf_counter: Accurate period data perf_counter: Introduce struct for sample data perf_counter tools: Normalize data using per sample period data perf_counter: Annotate exit ctx recursion perf_counter tools: Propagate signals properly perf_counter tools: Small frequency related fixes perf_counter: More aggressive frequency adjustment perf_counter/x86: Fix the model number of Intel Core2 processors perf_counter, x86: Correct some event and umask values for Intel processors ...
2009-06-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (44 commits) nommu: Provide mmap_min_addr definition. TOMOYO: Add description of lists and structures. TOMOYO: Remove unused field. integrity: ima audit dentry_open failure TOMOYO: Remove unused parameter. security: use mmap_min_addr indepedently of security models TOMOYO: Simplify policy reader. TOMOYO: Remove redundant markers. SELinux: define audit permissions for audit tree netlink messages TOMOYO: Remove unused mutex. tomoyo: avoid get+put of task_struct smack: Remove redundant initialization. integrity: nfsd imbalance bug fix rootplug: Remove redundant initialization. smack: do not beyond ARRAY_SIZE of data integrity: move ima_counts_get integrity: path_check update IMA: Add __init notation to ima functions IMA: Minimal IMA policy and boot param for TCB IMA policy selinux: remove obsolete read buffer limit from sel_read_bool ...
2009-06-11Merge branch 'linus' into perfcounters/coreIngo Molnar
Conflicts: arch/x86/kernel/irqinit.c arch/x86/kernel/irqinit_64.c arch/x86/kernel/traps.c arch/x86/mm/fault.c include/linux/sched.h kernel/exit.c
2009-05-22perf_counter: Dynamically allocate tasks' perf_counter_context structPaul Mackerras
This replaces the struct perf_counter_context in the task_struct with a pointer to a dynamically allocated perf_counter_context struct. The main reason for doing is this is to allow us to transfer a perf_counter_context from one task to another when we do lazy PMU switching in a later patch. This has a few side-benefits: the task_struct becomes a little smaller, we save some memory because only tasks that have perf_counters attached get a perf_counter_context allocated for them, and we can remove the inclusion of <linux/perf_counter.h> in sched.h, meaning that we don't end up recompiling nearly everything whenever perf_counter.h changes. The perf_counter_context structures are reference-counted and freed when the last reference is dropped. A context can have references from its task and the counters on its task. Counters can outlive the task so it is possible that a context will be freed well after its task has exited. Contexts are allocated on fork if the parent had a context, or otherwise the first time that a per-task counter is created on a task. In the latter case, we set the context pointer in the task struct locklessly using an atomic compare-and-exchange operation in case we raced with some other task in creating a context for the subject task. This also removes the task pointer from the perf_counter struct. The task pointer was not used anywhere and would make it harder to move a context from one task to another. Anything that needed to know which task a counter was attached to was already using counter->ctx->task. The __perf_counter_init_context function moves up in perf_counter.c so that it can be called from find_get_context, and now initializes the refcount, but is otherwise unchanged. We were potentially calling list_del_counter twice: once from __perf_counter_exit_task when the task exits and once from __perf_counter_remove_from_context when the counter's fd gets closed. This adds a check in list_del_counter so it doesn't do anything if the counter has already been removed from the lists. Since perf_counter_task_sched_in doesn't do anything if the task doesn't have a context, and leaves cpuctx->task_ctx = NULL, this adds code to __perf_install_in_context to set cpuctx->task_ctx if necessary, i.e. in the case where the current task adds the first counter to itself and thus creates a context for itself. This also adds similar code to __perf_counter_enable to handle a similar situation which can arise when the counters have been disabled using prctl; that also leaves cpuctx->task_ctx = NULL. [ Impact: refactor counter context management to prepare for new feature ] Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <18966.10075.781053.231153@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-20perf_counter: fix counter freeing logicIngo Molnar
Fix counter lifetime bugs which explain the crashes reported by Marcelo Tosatti and Arnaldo Carvalho de Melo. The new rule is: flushing + freeing is only done for a task's own counters, never for other tasks. [ Impact: fix crashes/lockups with inherited counters ] Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> Reported-by: Marcelo Tosatti <mtosatti@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-17perf_counter: fix threaded task exitIngo Molnar
Flushing counters in __exit_signal() with irqs disabled is not a good idea as perf_counter_exit_task() acquires mutexes. So flush it before acquiring the tasklist lock. (Note, we still need a fix for when the PID has been unhashed.) [ Impact: fix crash with inherited counters ] Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-17perf_counter: Fix counter inheritancePeter Zijlstra
Srivatsa Vaddagiri reported that a Java workload triggers this warning in kernel/exit.c: WARN_ON_ONCE(!list_empty(&tsk->perf_counter_ctx.counter_list)); Add the inherited counter propagation on self-detach, this could cause counter leaks and incomplete stats in threaded code like the below: #include <pthread.h> #include <unistd.h> void *thread(void *arg) { sleep(5); return NULL; } void main(void) { pthread_t thr; pthread_create(&thr, NULL, thread, NULL); } Reported-by: Srivatsa Vaddagiri <vatsa@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-08Merge branch 'master' into nextJames Morris
2009-05-01do_wait: do take security_task_wait() into accountOleg Nesterov
I was never able to understand what should we actually do when security_task_wait() fails, but the current code doesn't look right. If ->task_wait() returns the error, we update *notask_error correctly. But then we either reap the child (despite the fact this was forbidden) or clear *notask_error (and hide the securiy policy problems). This patch assumes that "stolen by ptrace" doesn't matter. If selinux denies the child we should ignore it but make sure we report -EACCESS instead of -ECHLD if there are no other eligible children. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-04-14tracing/events: move trace point headers into include/trace/eventsSteven Rostedt
Impact: clean up Create a sub directory in include/trace called events to keep the trace point headers in their own separate directory. Only headers that declare trace points should be defined in this directory. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14tracing: create automated trace definesSteven Rostedt
This patch lowers the number of places a developer must modify to add new tracepoints. The current method to add a new tracepoint into an existing system is to write the trace point macro in the trace header with one of the macros TRACE_EVENT, TRACE_FORMAT or DECLARE_TRACE, then they must add the same named item into the C file with the macro DEFINE_TRACE(name) and then add the trace point. This change cuts out the needing to add the DEFINE_TRACE(name). Every file that uses the tracepoint must still include the trace/<type>.h file, but the one C file must also add a define before the including of that file. #define CREATE_TRACE_POINTS #include <trace/mytrace.h> This will cause the trace/mytrace.h file to also produce the C code necessary to implement the trace point. Note, if more than one trace/<type>.h is used to create the C code it is best to list them all together. #define CREATE_TRACE_POINTS #include <trace/foo.h> #include <trace/bar.h> #include <trace/fido.h> Thanks to Mathieu Desnoyers and Christoph Hellwig for coming up with the cleaner solution of the define above the includes over my first design to have the C code include a "special" header. This patch converts sched, irq and lockdep and skb to use this new method. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-08Merge commit 'v2.6.30-rc1' into perfcounters/coreIngo Molnar
Conflicts: arch/powerpc/include/asm/systbl.h arch/powerpc/include/asm/unistd.h include/linux/init_task.h Merge reason: the conflicts are non-trivial: PowerPC placement of sys_perf_counter_open has to be mixed with the new preadv/pwrite syscalls. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-07Merge branch 'irq/threaded' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq/threaded' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: fix devres.o build for GENERIC_HARDIRQS=n genirq: provide old request_irq() for CONFIG_GENERIC_HARDIRQ=n genirq: threaded irq handlers review fixups genirq: add support for threaded interrupts to devres genirq: add threaded interrupt handler support
2009-04-07Merge branch 'linus' into perfcounters/coreIngo Molnar
Merge reason: need the upstream facility added by: 7f1e2ca: hrtimer: fix rq->lock inversion (again) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06exit_notify: kill the wrong capable(CAP_KILL) checkOleg Nesterov
The CAP_KILL check in exit_notify() looks just wrong, kill it. Whatever logic we have to reset ->exit_signal, the malicious user can bypass it if it execs the setuid application before exiting. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-06Merge branch 'linus' into perfcounters/core-v2Ingo Molnar
Merge reason: we have gathered quite a few conflicts, need to merge upstream Conflicts: arch/powerpc/kernel/Makefile arch/x86/ia32/ia32entry.S arch/x86/include/asm/hardirq.h arch/x86/include/asm/unistd_32.h arch/x86/include/asm/unistd_64.h arch/x86/kernel/cpu/common.c arch/x86/kernel/irq.c arch/x86/kernel/syscall_table_32.S arch/x86/mm/iomap_32.c include/linux/sched.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06Merge branch 'linus' into irq/threadedIngo Molnar
Conflicts: include/linux/irq.h kernel/irq/handle.c
2009-04-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: Remove two unneeded exports and make two symbols static in fs/mpage.c Cleanup after commit 585d3bc06f4ca57f975a5a1f698f65a45ea66225 Trim includes of fdtable.h Don't crap into descriptor table in binfmt_som Trim includes in binfmt_elf Don't mess with descriptor table in load_elf_binary() Get rid of indirect include of fs_struct.h New helper - current_umask() check_unsafe_exec() doesn't care about signal handlers sharing New locking/refcounting for fs_struct Take fs_struct handling to new file (fs/fs_struct.c) Get rid of bumping fs_struct refcount in pivot_root(2) Kill unsharing fs_struct in __set_personality()
2009-04-02pids: kill signal_struct-> __pgrp/__session and friendsOleg Nesterov
We are wasting 2 words in signal_struct without any reason to implement task_pgrp_nr() and task_session_nr(). task_session_nr() has no callers since 2e2ba22ea4fd4bb85f0fa37c521066db6775cbef, we can remove it. task_pgrp_nr() is still (I believe wrongly) used in fs/autofsX and fs/coda. This patch reimplements task_pgrp_nr() via task_pgrp_nr_ns(), and kills __pgrp/__session and the related helpers. The change in drivers/char/tty_io.c is cosmetic, but hopefully makes sense anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Alan Cox <number6@the-village.bc.nu> [tty parts] Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02pids: improve get_task_pid() to fix the unsafe sys_wait4()->task_pgrp()Oleg Nesterov
sys_wait4() does get_pid(task_pgrp(current)), this is not safe. We can add rcu lock/unlock around, but we already have get_task_pid() which can be improved to handle the special pids in more reliable manner. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Louis Rilling <Louis.Rilling@kerlabs.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02forget_original_parent: do not abuse child->ptrace_entryOleg Nesterov
By discussion with Roland. - Use ->sibling instead of ->ptrace_entry to chain the need to be release_task'd childs. Nobody else can use ->sibling, this task is EXIT_DEAD and nobody can find it on its own list. - rename ptrace_dead to dead_childs. - Now that we don't have the "parallel" untrace code, change back reparent_thread() to return void, pass dead_childs as an argument. Actually, I don't understand why do we notify /sbin/init when we reparent a zombie, probably it is better to reap it unconditionally. [akpm@linux-foundation.org: s/childs/children/] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Metzger, Markus T" <markus.t.metzger@intel.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02forget_original_parent: split out the un-ptrace partOleg Nesterov
By discussion with Roland. - Rename ptrace_exit() to exit_ptrace(), and change it to do all the necessary work with ->ptraced list by its own. - Move this code from exit.c to ptrace.c - Update the comment in ptrace_detach() to explain the rechecking of the child->ptrace. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Metzger, Markus T" <markus.t.metzger@intel.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02reparent_thread: fix a zombie leak if /sbin/init ignores SIGCHLDOleg Nesterov
If /sbin/init ignores SIGCHLD and we re-parent a zombie, it is leaked. reparent_thread() does do_notify_parent() which sets ->exit_signal = -1 in this case. This means that nobody except us can reap it, the detached task is not visible to do_wait(). Change reparent_thread() to return a boolean (like __pthread_detach) to indicate that the thread is dead and must be released. Also change forget_original_parent() to add the child to ptrace_dead list in this case. The naming becomes insane, the next patch does the cleanup. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02reparent_thread: fix the "is it traced" checkOleg Nesterov
reparent_thread() uses ptrace_reparented() to check whether this thread is ptraced, in that case we should not notify the new parent. But ptrace_reparented() is not exactly correct when the reparented thread is traced by /sbin/init, because forget_original_parent() has already changed ->real_parent. Currently, the only problem is the false notification. But with the next patch the kernel crash in this (yes, pathological) case. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02reparent_thread: don't call kill_orphaned_pgrp() if task_detached()Oleg Nesterov
If task_detached(p) == T, then either a) p is not the main thread, we will find the group leader on the ->children list. or b) p is the group leader but its ->exit_state = EXIT_DEAD. This can only happen when the last sub-thread has died, but in that case that thread has already called kill_orphaned_pgrp() from exit_notify(). In both cases kill_orphaned_pgrp() looks bogus. Move the task_detached() check up and simplify the code, this is also right from the "common sense" pov: we should do nothing with the detached childs, except move them to the new parent's ->children list. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02ptrace: reintroduce __ptrace_detach() as a callee of ptrace_exit()Oleg Nesterov
No functional changes, preparation for the next patch. Move the "should we release this child" logic into the separate handler, __ptrace_detach(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02ptrace: simplify ptrace_exit()->ignoring_children() pathOleg Nesterov
ignoring_children() takes parent->sighand->siglock and checks k_sigaction[SIGCHLD] atomically. But this buys nothing, we can't get the "really" wrong result even if we race with sigaction(SIGCHLD). If we read the "stale" sa_handler/sa_flags we can pretend it was changed right after the check. Remove spin_lock(->siglock), and kill "int ign" which caches the result of ignoring_children() which becomes rather trivial. Perhaps it makes sense to export this helper, do_notify_parent() can use it too. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02do_wait: fix waiting for the group stop with the dead leaderOleg Nesterov
do_wait(WSTOPPED) assumes that p->state must be == TASK_STOPPED, this is not true if the leader is already dead. Check SIGNAL_STOP_STOPPED instead and use signal->group_exit_code. Trivial test-case: void *tfunc(void *arg) { pause(); return NULL; } int main(void) { pthread_t thr; pthread_create(&thr, NULL, tfunc, NULL); pthread_exit(NULL); return 0; } It doesn't react to ^Z (and then to ^C or ^\). The task is stopped, but bash can't see this. The bug is very old, and it was reported multiple times. This patch was sent more than a year ago (http://marc.info/?t=119713920000003) but it was ignored. This change also fixes other oddities (but not all) in this area. For example, before this patch: $ sleep 100 ^Z [1]+ Stopped sleep 100 $ strace -p `pidof sleep` Process 11442 attached - interrupt to quit strace hangs in do_wait(), because ->exit_code was already consumed by bash. After this patch, strace happily proceeds: --- SIGTSTP (Stopped) @ 0 (0) --- restart_syscall(<... resuming interrupted call ...> To me, this looks much more "natural" and correct. Another example. Let's suppose we have the main thread M and sub-thread T, the process is stopped, and its parent did wait(WSTOPPED). Now we can ptrace T but not M. This looks at least strange to me. Imho, do_wait() should not confuse the per-thread ptrace stops with the per-process job control stops. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Kaz Kylheku <kkylheku@gmail.com> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Roland McGrath <roland@redhat.com> Cc: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-31Get rid of indirect include of fs_struct.hAl Viro
Don't pull it in sched.h; very few files actually need it and those can include directly. sched.h itself only needs forward declaration of struct fs_struct; Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31Take fs_struct handling to new file (fs/fs_struct.c)Al Viro
Pure code move; two new helper functions for nfsd and daemonize (unshare_fs_struct() and daemonize_fs_struct() resp.; for now - the same code as used to be in callers). unshare_fs_struct() exported (for nfsd, as copy_fs_struct()/exit_fs() used to be), copy_fs_struct() and exit_fs() don't need exports anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-24genirq: add threaded interrupt handler supportThomas Gleixner
Add support for threaded interrupt handlers: A device driver can request that its main interrupt handler runs in a thread. To achive this the device driver requests the interrupt with request_threaded_irq() and provides additionally to the handler a thread function. The handler function is called in hard interrupt context and needs to check whether the interrupt originated from the device. If the interrupt originated from the device then the handler can either return IRQ_HANDLED or IRQ_WAKE_THREAD. IRQ_HANDLED is returned when no further action is required. IRQ_WAKE_THREAD causes the genirq code to invoke the threaded (main) handler. When IRQ_WAKE_THREAD is returned handler must have disabled the interrupt on the device level. This is mandatory for shared interrupt handlers, but we need to do it as well for obscure x86 hardware where disabling an interrupt on the IO_APIC level redirects the interrupt to the legacy PIC interrupt lines. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2009-02-13Merge branch 'linus' into x86/apicIngo Molnar
Conflicts: arch/x86/kernel/acpi/boot.c arch/x86/mm/fault.c
2009-02-13Merge branch 'linus' into perfcounters/coreIngo Molnar
Conflicts: arch/x86/kernel/acpi/boot.c
2009-02-05signal: re-add dead task accumulation stats.Peter Zijlstra
We're going to split the process wide cpu accounting into two parts: - clocks; which can take all the time they want since they run from user context. - timers; which need constant time tracing but can affort the overhead because they're default off -- and rare. The clock readout will go back to a full sum of the thread group, for this we need to re-add the exit stats that were removed in the initial itimer rework (f06febc9: timers: fix itimer/many thread hang). Furthermore, since that full sum can be rather slow for large thread groups and we have the complete dead task stats, revert the do_notify_parent time computation. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-23Merge branch 'core/percpu' into perfcounters/coreIngo Molnar
Conflicts: arch/x86/include/asm/hardirq_32.h arch/x86/include/asm/hardirq_64.h Semantic merge: arch/x86/include/asm/hardirq.h [ added apic_perf_irqs field. ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21Merge commit 'v2.6.29-rc2' into perfcounters/coreIngo Molnar
Conflicts: include/linux/syscalls.h