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authorRichard Larocque <rlarocque@google.com>2014-09-09 18:31:04 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-10-05 14:54:14 -0700
commit5cebda5d05729708008637b3161076beb5855a71 (patch)
treef33293620688da9f0b916047315dab84146441a0
parent178ba7e09f5fc6847b2b1a814506e6e0e354013d (diff)
downloadlinux-linaro-stable-5cebda5d05729708008637b3161076beb5855a71.tar.gz
alarmtimer: Do not signal SIGEV_NONE timers
commit 265b81d23a46c39df0a735a3af4238954b41a4c2 upstream. 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: 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 294bf4ef1f47..a2d2a480701c 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -421,8 +421,10 @@ 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) {