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authorRichard Larocque <rlarocque@google.com>2014-09-10 05:31:04 +0400
committerJohn Stultz <john.stultz@linaro.org>2014-09-13 00:59:12 +0400
commit265b81d23a46c39df0a735a3af4238954b41a4c2 (patch)
tree47b81c013a71d8e8a31a821b2b97674ab7c97cf2 /kernel/time
parente86fea764991e00a03ff1e56409ec9cacdbda4c9 (diff)
downloadlinux-265b81d23a46c39df0a735a3af4238954b41a4c2.tar.xz
alarmtimer: Do not signal SIGEV_NONE timers
Avoids sending a signal to alarm timers created with sigev_notify set to SIGEV_NONE by checking for that special case in the timeout callback. The regular posix timers avoid sending signals to SIGEV_NONE timers by not scheduling any callbacks for them in the first place. Although it would be possible to do something similar for alarm timers, it's simpler to handle this as a special case in the timeout. Prior to this patch, the alarm timer would ignore the sigev_notify value and try to deliver signals to the process anyway. Even worse, the sanity check for the value of sigev_signo is skipped when SIGEV_NONE was specified, so the signal number could be bogus. If sigev_signo was an unitialized value (as it often would be if SIGEV_NONE is used), then it's hard to predict which signal will be sent. Cc: stable@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Signed-off-by: Richard Larocque <rlarocque@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'kernel/time')
-rw-r--r--kernel/time/alarmtimer.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index b4bce62e47b2..41a925396830 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -466,8 +466,10 @@ static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
{
struct k_itimer *ptr = container_of(alarm, struct k_itimer,
it.alarm.alarmtimer);
- if (posix_timer_event(ptr, 0) != 0)
- ptr->it_overrun++;
+ if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) {
+ if (posix_timer_event(ptr, 0) != 0)
+ ptr->it_overrun++;
+ }
/* Re-add periodic timers */
if (ptr->it.alarm.interval.tv64) {