[PATCH 5.11 37/44] ia64: dont call handle_signal() unless theres actually a signal queued

[gregkh]

From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

From: Jens Axboe <axboe@xxxxxxxxx>

[ Upstream commit f5f4fc4649ae542b1a25670b17aaf3cbb6187acc ]

Sergei and John both reported that ia64 failed to boot in 5.11, and it
was related to signals. Turns out the ia64 signal handling is a bit odd,
it doesn't check the return value of get_signal() for whether there's a
signal to deliver or not. With the introduction of TIF_NOTIFY_SIGNAL,
then task_work could trigger it.

Fix it by only calling handle_signal() if we actually have a real signal
to deliver. This brings it in line with all other archs, too.

Fixes: b269c229b0e8 ("ia64: add support for TIF_NOTIFY_SIGNAL")
Reported-by: Sergei Trofimovich <slyich@xxxxxxxxx>
Reported-by: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Tested-by: Sergei Trofimovich <slyich@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/ia64/kernel/signal.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/ia64/kernel/signal.c b/arch/ia64/kernel/signal.c
index e67b22fc3c60..c1b299760bf7 100644
--- a/arch/ia64/kernel/signal.c
+++ b/arch/ia64/kernel/signal.c
@@ -341,7 +341,8 @@ ia64_do_signal (struct sigscratch *scr, long in_syscall)
 	 * need to push through a forced SIGSEGV.
 	 */
 	while (1) {
-		get_signal(&ksig);
+		if (!get_signal(&ksig))
+			break;
 
 		/*
 		 * get_signal() may have run a debugger (via notify_parent())
-- 
2.30.1