3.2.64-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Richard Larocque <rlaroc...@google.com>
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 <t...@linutronix.de>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Richard Cochran <richardcoch...@gmail.com>
Cc: Prarit Bhargava <pra...@redhat.com>
Cc: Sharvil Nanavati <shar...@google.com>
Signed-off-by: Richard Larocque <rlaroc...@google.com>
Signed-off-by: John Stultz <john.stu...@linaro.org>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
kernel/time/alarmtimer.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -448,8 +448,12 @@ static enum alarmtimer_type clock2alarm(
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++;
@@ -459,9 +463,11 @@ static enum alarmtimer_restart alarm_han
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;
}
/**
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
