diff mbox series

connectors/pec_listener: Make exit_flag volatile

Message ID 20210809105826.19674-1-mdoucha@suse.cz
State Accepted
Headers show
Series connectors/pec_listener: Make exit_flag volatile | expand

Commit Message

Martin Doucha Aug. 9, 2021, 10:58 a.m. UTC 
There are two ways in which the main loop of pec_listener can stop:
- syscall gets interrupted by signal and its error handler code breaks the loop
- or exit_flag get set to 1

The exit flag is only changed in signal handler so it needs to be volatile,
otherwise the compiler will optimize it out of the main program loop. If
an incoming signal doesn't interrupt a syscall, pec_listener will get stuck
in the loop forever. It's a rare situation but it does happen once in a while.

Signed-off-by: Martin Doucha <mdoucha@suse.cz>
---
 testcases/kernel/connectors/pec/pec_listener.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Cyril Hrubis Aug. 9, 2021, 11:01 a.m. UTC | #1 
Hi!
Good catch, applied, thanks.
diff mbox series

Patch

diff --git a/testcases/kernel/connectors/pec/pec_listener.c b/testcases/kernel/connectors/pec/pec_listener.c
index 7844dc905..2707ea8fb 100644
--- a/testcases/kernel/connectors/pec/pec_listener.c
+++ b/testcases/kernel/connectors/pec/pec_listener.c
@@ -50,7 +50,7 @@  int main(void)
 
 static __u32 seq;
 
-static int exit_flag;
+static volatile int exit_flag;
 static struct sigaction sigint_action;
 
 struct nlmsghdr *nlhdr;