From 80a256fcf9aefa963ab4d8a4ce102da3e2677555 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Tue, 27 Mar 2018 15:58:16 +0200 Subject: [PATCH 359/365] alarmtimer: Prevent live lock in alarm_cancel() If alarm_try_to_cancel() requires a retry, then depending on the priority setting the retry loop might prevent timer callback completion on RT. Prevent that by waiting for completion on RT, no change for a non RT kernel. Cc: stable-rt@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior (cherry picked from commit 51e376c469bf05f32cb1ceb9e39d31bb92f1f6c8) Signed-off-by: Julia Cartwright --- kernel/time/alarmtimer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index be2606cd19d3..bff3f9945ac2 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -417,7 +417,7 @@ int alarm_cancel(struct alarm *alarm) int ret = alarm_try_to_cancel(alarm); if (ret >= 0) return ret; - cpu_relax(); + hrtimer_wait_for_timer(&alarm->timer); } } EXPORT_SYMBOL_GPL(alarm_cancel); -- 2.28.0