signals: avoid random wakeups in sigsuspend()

A random wakeup can get us out of sigsuspend() without TIF_SIGPENDING
being set.

Avoid that by making sure we were signaled, like sys_pause() does.

Signed-off-by: Sasha Levin <[email protected]>
Acked-by: Oleg Nesterov <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Sasha Levin 2016-02-05 15:36:05 -08:00 • committed by Linus Torvalds
commit 823dd3224a

View file

@ -3508,8 +3508,10 @@ static int sigsuspend(sigset_t *set)
current->saved_sigmask = current->blocked;
set_current_blocked(set);
__set_current_state(TASK_INTERRUPTIBLE);
schedule();
while (!signal_pending(current)) {
__set_current_state(TASK_INTERRUPTIBLE);
schedule();
}
set_restore_sigmask();
return -ERESTARTNOHAND;
}