From 3c47864204b4df3e0d506c5a53cc7f1111467411 Mon Sep 17 00:00:00 2001 From: Richard Larocque Date: Tue, 9 Sep 2014 18:31:05 -0700 Subject: [PATCH] alarmtimer: Lock k_itimer during timer callback commit 474e941bed9262f5fa2394f9a4a67e24499e5926 upstream. 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: Thomas Gleixner Cc: Ingo Molnar Cc: Richard Cochran Cc: Prarit Bhargava Cc: Sharvil Nanavati Signed-off-by: Richard Larocque Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- kernel/time/alarmtimer.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index a2d2a480701c..7d19fca0617e 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -419,8 +419,12 @@ 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++; @@ -430,9 +434,11 @@ 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; } /** -- 2.20.1