alarmtimer: Lock k_itimer during timer callback (474e941b) · Commits · 戴 / test

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 <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>

kernel/time/alarmtimer.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -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;
		}

		/**

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