From 823dd3224a07f618d652a7743c9603222d019de3 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sasha.levin@oracle.com>
Date: Fri, 5 Feb 2016 15:36:05 -0800
Subject: [PATCH] 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 <sasha.levin@oracle.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
kernel/signal.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/signal.c b/kernel/signal.c
index f3f1f7a972fd4..0508544c8ced0 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -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;
}
--
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