[PATCH] signals: work around random wakeups in sigsuspend()

From: Sasha Levin
Date: Mon Jan 25 2016 - 10:53:02 EST


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 <sasha.levin@xxxxxxxxxx>
---
kernel/signal.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 5da9180..3256c7e 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3528,8 +3528,10 @@ 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;
}
--
1.7.10.4