From 474e941bed9262f5fa2394f9a4a67e24499e5926 Mon Sep 17 00:00:00 2001 From: Richard Larocque Date: Tue, 9 Sep 2014 18:31:05 -0700 Subject: alarmtimer: Lock k_itimer during timer callback Locks the k_itimer's it_lock member when handling the alarm timer's expiry callback. The regular posix timers defined in posix-timers.c have this lock held during timout processing because their callbacks are routed through posix_timer_fn(). The alarm timers follow a different path, so they ought to grab the lock somewhere else. Cc: stable@vger.kernel.org Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Richard Cochran Cc: Prarit Bhargava Cc: Sharvil Nanavati Signed-off-by: Richard Larocque Signed-off-by: John Stultz --- kernel/time/alarmtimer.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'kernel/time/alarmtimer.c') diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 41a925396830..a7077d3ae52f 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -464,8 +464,12 @@ static enum alarmtimer_type clock2alarm(clockid_t clockid) static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, ktime_t now) { + unsigned long flags; struct k_itimer *ptr = container_of(alarm, struct k_itimer, it.alarm.alarmtimer); + enum alarmtimer_restart result = ALARMTIMER_NORESTART; + + spin_lock_irqsave(&ptr->it_lock, flags); if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) { if (posix_timer_event(ptr, 0) != 0) ptr->it_overrun++; @@ -475,9 +479,11 @@ static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, if (ptr->it.alarm.interval.tv64) { ptr->it_overrun += alarm_forward(alarm, now, ptr->it.alarm.interval); - return ALARMTIMER_RESTART; + result = ALARMTIMER_RESTART; } - return ALARMTIMER_NORESTART; + spin_unlock_irqrestore(&ptr->it_lock, flags); + + return result; } /** -- cgit v1.2.3