ptrace: task_clear_jobctl_trapping()->wake_up_bit() needs mb()

__wake_up_bit() checks waitqueue_active() and thus the caller needs mb()
as wake_up_bit() documents, fix task_clear_jobctl_trapping().

Signed-off-by: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Oleg Nesterov 2014-06-06 14:36:44 -07:00 • committed by Linus Torvalds
commit 650226bd95

View file

@ -277,6 +277,7 @@ void task_clear_jobctl_trapping(struct task_struct *task)
{
if (unlikely(task->jobctl & JOBCTL_TRAPPING)) {
task->jobctl &= ~JOBCTL_TRAPPING;
smp_mb(); /* advised by wake_up_bit() */
wake_up_bit(&task->jobctl, JOBCTL_TRAPPING_BIT);
}
}