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| author | Richard Larocque <rlarocque@google.com> | 2014-09-09 18:31:05 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-05 13:41:08 -0700 |
| commit | 6ba3934df8b88f6593da479e1418c8219d4f5396 (patch) | |
| tree | 1044c39ef64600246790397029fbd13c4dd8bda9 | |
| parent | f11d225925676e7fa5e95caa3c3116bfb2caa0b2 (diff) | |
| download | linux-stable-6ba3934df8b88f6593da479e1418c8219d4f5396.tar.gz linux-stable-6ba3934df8b88f6593da479e1418c8219d4f5396.tar.bz2 linux-stable-6ba3934df8b88f6593da479e1418c8219d4f5396.zip | |
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 <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.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index f7bdb143696a..cd45a0727a16 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; } /** |