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move exit_task_work() past exit_files() et.al.

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... and get rid of PF_EXITING check in task_work_add().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-06-27 11:31:24 +04:00
parent 67d1214551
commit ed3e694d78
2 changed files with 13 additions and 23 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

6
kernel/exit.c
View file

@ -953,14 +953,11 @@ void do_exit(long code)
exit_signals(tsk); /* sets PF_EXITING */ exit_signals(tsk); /* sets PF_EXITING */
/* /*
* tsk->flags are checked in the futex code to protect against * tsk->flags are checked in the futex code to protect against
* an exiting task cleaning up the robust pi futexes, and in * an exiting task cleaning up the robust pi futexes.
* task_work_add() to avoid the race with exit_task_work().
*/ */
smp_mb(); smp_mb();
raw_spin_unlock_wait(&tsk->pi_lock); raw_spin_unlock_wait(&tsk->pi_lock);
exit_task_work(tsk);
if (unlikely(in_atomic())) if (unlikely(in_atomic()))
printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
current->comm, task_pid_nr(current), current->comm, task_pid_nr(current),
@ -995,6 +992,7 @@ void do_exit(long code)
exit_shm(tsk); exit_shm(tsk);
exit_files(tsk); exit_files(tsk);
exit_fs(tsk); exit_fs(tsk);
exit_task_work(tsk);
check_stack_usage(); check_stack_usage();
exit_thread(); exit_thread();

30
kernel/task_work.c
View file

@ -5,34 +5,26 @@
int int
task_work_add(struct task_struct *task, struct callback_head *twork, bool notify) task_work_add(struct task_struct *task, struct callback_head *twork, bool notify)
{ {
struct callback_head *last, *first;
unsigned long flags; unsigned long flags;
int err = -ESRCH;
#ifndef TIF_NOTIFY_RESUME
if (notify)
return -ENOTSUPP;
#endif
/* /*
* We must not insert the new work if the task has already passed * Not inserting the new work if the task has already passed
* exit_task_work(). We rely on do_exit()->raw_spin_unlock_wait() * exit_task_work() is the responisbility of callers.
* and check PF_EXITING under pi_lock.
*/ */
raw_spin_lock_irqsave(&task->pi_lock, flags); raw_spin_lock_irqsave(&task->pi_lock, flags);
if (likely(!(task->flags & PF_EXITING))) { last = task->task_works;
struct callback_head *last = task->task_works; first = last ? last->next : twork;
struct callback_head *first = last ? last->next : twork; twork->next = first;
twork->next = first; if (last)
if (last) last->next = twork;
last->next = twork; task->task_works = twork;
task->task_works = twork;
err = 0;
}
raw_spin_unlock_irqrestore(&task->pi_lock, flags); raw_spin_unlock_irqrestore(&task->pi_lock, flags);
/* test_and_set_bit() implies mb(), see tracehook_notify_resume(). */ /* test_and_set_bit() implies mb(), see tracehook_notify_resume(). */
if (likely(!err) && notify) if (notify)
set_notify_resume(task); set_notify_resume(task);
return err; return 0;
} }
struct callback_head * struct callback_head *