Fix signalfd interaction with thread-private signals

caec4e8d · Benjamin Herrenschmidt <[email protected]> · 2007-06-12 08:16:18 +10:00

Don't let signalfd dequeue private signals off other threads (in the
case of things like SIGILL or SIGSEGV, trying to do so would result
in undefined behaviour on who actually gets the signal, since they
are force unblocked).

Signed-off-by: Benjamin Herrenschmidt <[email protected]>
Acked-by: Davide Libenzi <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: caec4e8dc85e0644ec24aeb36285e1ba02da58cc
Parents: bd197234

Changes

1 files changed · +7 −1

File	Status	Add	Del	Content
kernel/signal.c	modified	+7	−1	View file

kernel/signal.c

View file

diff --git a/kernel/signal.c b/kernel/signal.c
index fe590e0..f940560 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -363,7 +363,13 @@ static int __dequeue_signal(struct sigpending *pending, sigset_t *mask,
  */
 int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 {
-	int signr = __dequeue_signal(&tsk->pending, mask, info);
+	int signr = 0;
+
+	/* We only dequeue private signals from ourselves, we don't let
+	 * signalfd steal them
+	 */
+	if (tsk == current)
+		signr = __dequeue_signal(&tsk->pending, mask, info);
 	if (!signr) {
 		signr = __dequeue_signal(&tsk->signal->shared_pending,
 					 mask, info);