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Diffstat (limited to 'kernel/exit.c')
-rw-r--r--kernel/exit.c250
1 files changed, 72 insertions, 178 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index d2e8239ea187..036e8d740169 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -46,6 +46,7 @@
#include <linux/blkdev.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/tracehook.h>
+#include <linux/fs_struct.h>
#include <linux/init_task.h>
#include <trace/sched.h>
@@ -61,11 +62,6 @@ DEFINE_TRACE(sched_process_wait);
static void exit_mm(struct task_struct * tsk);
-static inline int task_detached(struct task_struct *p)
-{
- return p->exit_signal == -1;
-}
-
static void __unhash_process(struct task_struct *p)
{
nr_threads--;
@@ -362,16 +358,12 @@ static void reparent_to_kthreadd(void)
void __set_special_pids(struct pid *pid)
{
struct task_struct *curr = current->group_leader;
- pid_t nr = pid_nr(pid);
- if (task_session(curr) != pid) {
+ if (task_session(curr) != pid)
change_pid(curr, PIDTYPE_SID, pid);
- set_task_session(curr, nr);
- }
- if (task_pgrp(curr) != pid) {
+
+ if (task_pgrp(curr) != pid)
change_pid(curr, PIDTYPE_PGID, pid);
- set_task_pgrp(curr, nr);
- }
}
static void set_special_pids(struct pid *pid)
@@ -429,7 +421,6 @@ EXPORT_SYMBOL(disallow_signal);
void daemonize(const char *name, ...)
{
va_list args;
- struct fs_struct *fs;
sigset_t blocked;
va_start(args, name);
@@ -462,11 +453,7 @@ void daemonize(const char *name, ...)
/* Become as one with the init task */
- exit_fs(current); /* current->fs->count--; */
- fs = init_task.fs;
- current->fs = fs;
- atomic_inc(&fs->count);
-
+ daemonize_fs_struct();
exit_files(current);
current->files = init_task.files;
atomic_inc(&current->files->count);
@@ -565,30 +552,6 @@ void exit_files(struct task_struct *tsk)
}
}
-void put_fs_struct(struct fs_struct *fs)
-{
- /* No need to hold fs->lock if we are killing it */
- if (atomic_dec_and_test(&fs->count)) {
- path_put(&fs->root);
- path_put(&fs->pwd);
- kmem_cache_free(fs_cachep, fs);
- }
-}
-
-void exit_fs(struct task_struct *tsk)
-{
- struct fs_struct * fs = tsk->fs;
-
- if (fs) {
- task_lock(tsk);
- tsk->fs = NULL;
- task_unlock(tsk);
- put_fs_struct(fs);
- }
-}
-
-EXPORT_SYMBOL_GPL(exit_fs);
-
#ifdef CONFIG_MM_OWNER
/*
* Task p is exiting and it owned mm, lets find a new owner for it
@@ -732,119 +695,6 @@ static void exit_mm(struct task_struct * tsk)
}
/*
- * Return nonzero if @parent's children should reap themselves.
- *
- * Called with write_lock_irq(&tasklist_lock) held.
- */
-static int ignoring_children(struct task_struct *parent)
-{
- int ret;
- struct sighand_struct *psig = parent->sighand;
- unsigned long flags;
- spin_lock_irqsave(&psig->siglock, flags);
- ret = (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN ||
- (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT));
- spin_unlock_irqrestore(&psig->siglock, flags);
- return ret;
-}
-
-/*
- * Detach all tasks we were using ptrace on.
- * Any that need to be release_task'd are put on the @dead list.
- *
- * Called with write_lock(&tasklist_lock) held.
- */
-static void ptrace_exit(struct task_struct *parent, struct list_head *dead)
-{
- struct task_struct *p, *n;
- int ign = -1;
-
- list_for_each_entry_safe(p, n, &parent->ptraced, ptrace_entry) {
- __ptrace_unlink(p);
-
- if (p->exit_state != EXIT_ZOMBIE)
- continue;
-
- /*
- * If it's a zombie, our attachedness prevented normal
- * parent notification or self-reaping. Do notification
- * now if it would have happened earlier. If it should
- * reap itself, add it to the @dead list. We can't call
- * release_task() here because we already hold tasklist_lock.
- *
- * If it's our own child, there is no notification to do.
- * But if our normal children self-reap, then this child
- * was prevented by ptrace and we must reap it now.
- */
- if (!task_detached(p) && thread_group_empty(p)) {
- if (!same_thread_group(p->real_parent, parent))
- do_notify_parent(p, p->exit_signal);
- else {
- if (ign < 0)
- ign = ignoring_children(parent);
- if (ign)
- p->exit_signal = -1;
- }
- }
-
- if (task_detached(p)) {
- /*
- * Mark it as in the process of being reaped.
- */
- p->exit_state = EXIT_DEAD;
- list_add(&p->ptrace_entry, dead);
- }
- }
-}
-
-/*
- * Finish up exit-time ptrace cleanup.
- *
- * Called without locks.
- */
-static void ptrace_exit_finish(struct task_struct *parent,
- struct list_head *dead)
-{
- struct task_struct *p, *n;
-
- BUG_ON(!list_empty(&parent->ptraced));
-
- list_for_each_entry_safe(p, n, dead, ptrace_entry) {
- list_del_init(&p->ptrace_entry);
- release_task(p);
- }
-}
-
-static void reparent_thread(struct task_struct *p, struct task_struct *father)
-{
- if (p->pdeath_signal)
- /* We already hold the tasklist_lock here. */
- group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p);
-
- list_move_tail(&p->sibling, &p->real_parent->children);
-
- /* If this is a threaded reparent there is no need to
- * notify anyone anything has happened.
- */
- if (same_thread_group(p->real_parent, father))
- return;
-
- /* We don't want people slaying init. */
- if (!task_detached(p))
- p->exit_signal = SIGCHLD;
-
- /* If we'd notified the old parent about this child's death,
- * also notify the new parent.
- */
- if (!ptrace_reparented(p) &&
- p->exit_state == EXIT_ZOMBIE &&
- !task_detached(p) && thread_group_empty(p))
- do_notify_parent(p, p->exit_signal);
-
- kill_orphaned_pgrp(p, father);
-}
-
-/*
* When we die, we re-parent all our children.
* Try to give them to another thread in our thread
* group, and if no such member exists, give it to
@@ -883,17 +733,51 @@ static struct task_struct *find_new_reaper(struct task_struct *father)
return pid_ns->child_reaper;
}
+/*
+* Any that need to be release_task'd are put on the @dead list.
+ */
+static void reparent_thread(struct task_struct *father, struct task_struct *p,
+ struct list_head *dead)
+{
+ if (p->pdeath_signal)
+ group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p);
+
+ list_move_tail(&p->sibling, &p->real_parent->children);
+
+ if (task_detached(p))
+ return;
+ /*
+ * If this is a threaded reparent there is no need to
+ * notify anyone anything has happened.
+ */
+ if (same_thread_group(p->real_parent, father))
+ return;
+
+ /* We don't want people slaying init. */
+ p->exit_signal = SIGCHLD;
+
+ /* If it has exited notify the new parent about this child's death. */
+ if (!p->ptrace &&
+ p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) {
+ do_notify_parent(p, p->exit_signal);
+ if (task_detached(p)) {
+ p->exit_state = EXIT_DEAD;
+ list_move_tail(&p->sibling, dead);
+ }
+ }
+
+ kill_orphaned_pgrp(p, father);
+}
+
static void forget_original_parent(struct task_struct *father)
{
struct task_struct *p, *n, *reaper;
- LIST_HEAD(ptrace_dead);
+ LIST_HEAD(dead_children);
+
+ exit_ptrace(father);
write_lock_irq(&tasklist_lock);
reaper = find_new_reaper(father);
- /*
- * First clean up ptrace if we were using it.
- */
- ptrace_exit(father, &ptrace_dead);
list_for_each_entry_safe(p, n, &father->children, sibling) {
p->real_parent = reaper;
@@ -901,13 +785,16 @@ static void forget_original_parent(struct task_struct *father)
BUG_ON(p->ptrace);
p->parent = p->real_parent;
}
- reparent_thread(p, father);
+ reparent_thread(father, p, &dead_children);
}
-
write_unlock_irq(&tasklist_lock);
+
BUG_ON(!list_empty(&father->children));
- ptrace_exit_finish(father, &ptrace_dead);
+ list_for_each_entry_safe(p, n, &dead_children, sibling) {
+ list_del_init(&p->sibling);
+ release_task(p);
+ }
}
/*
@@ -950,8 +837,7 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
*/
if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) &&
(tsk->parent_exec_id != tsk->real_parent->self_exec_id ||
- tsk->self_exec_id != tsk->parent_exec_id) &&
- !capable(CAP_KILL))
+ tsk->self_exec_id != tsk->parent_exec_id))
tsk->exit_signal = SIGCHLD;
signal = tracehook_notify_death(tsk, &cookie, group_dead);
@@ -1037,6 +923,8 @@ NORET_TYPE void do_exit(long code)
schedule();
}
+ exit_irq_thread();
+
exit_signals(tsk); /* sets PF_EXITING */
/*
* tsk->flags are checked in the futex code to protect against
@@ -1417,6 +1305,18 @@ static int wait_task_zombie(struct task_struct *p, int options,
return retval;
}
+static int *task_stopped_code(struct task_struct *p, bool ptrace)
+{
+ if (ptrace) {
+ if (task_is_stopped_or_traced(p))
+ return &p->exit_code;
+ } else {
+ if (p->signal->flags & SIGNAL_STOP_STOPPED)
+ return &p->signal->group_exit_code;
+ }
+ return NULL;
+}
+
/*
* Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
* read_lock(&tasklist_lock) on entry. If we return zero, we still hold
@@ -1427,7 +1327,7 @@ static int wait_task_stopped(int ptrace, struct task_struct *p,
int options, struct siginfo __user *infop,
int __user *stat_addr, struct rusage __user *ru)
{
- int retval, exit_code, why;
+ int retval, exit_code, *p_code, why;
uid_t uid = 0; /* unneeded, required by compiler */
pid_t pid;
@@ -1437,22 +1337,16 @@ static int wait_task_stopped(int ptrace, struct task_struct *p,
exit_code = 0;
spin_lock_irq(&p->sighand->siglock);
- if (unlikely(!task_is_stopped_or_traced(p)))
- goto unlock_sig;
-
- if (!ptrace && p->signal->group_stop_count > 0)
- /*
- * A group stop is in progress and this is the group leader.
- * We won't report until all threads have stopped.
- */
+ p_code = task_stopped_code(p, ptrace);
+ if (unlikely(!p_code))
goto unlock_sig;
- exit_code = p->exit_code;
+ exit_code = *p_code;
if (!exit_code)
goto unlock_sig;
if (!unlikely(options & WNOWAIT))
- p->exit_code = 0;
+ *p_code = 0;
/* don't need the RCU readlock here as we're holding a spinlock */
uid = __task_cred(p)->uid;
@@ -1609,7 +1503,7 @@ static int wait_consider_task(struct task_struct *parent, int ptrace,
*/
*notask_error = 0;
- if (task_is_stopped_or_traced(p))
+ if (task_stopped_code(p, ptrace))
return wait_task_stopped(ptrace, p, options,
infop, stat_addr, ru);
@@ -1813,7 +1707,7 @@ SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
pid = find_get_pid(-upid);
} else if (upid == 0) {
type = PIDTYPE_PGID;
- pid = get_pid(task_pgrp(current));
+ pid = get_task_pid(current, PIDTYPE_PGID);
} else /* upid > 0 */ {
type = PIDTYPE_PID;
pid = find_get_pid(upid);