From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 1 Mar 2017 16:30:49 +0100
Subject: timer/hrtimer: check properly for a running timer
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: 9ef3a9cde8dae3744088725b24c4443fb4ce86fb
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension

hrtimer_callback_running() checks only whether a timmer is running on a
CPU in hardirq-context. This is okay for !RT. For RT environment we move
most timers to the timer-softirq and therefore we therefore need to
check if the timer is running in the softirq context.

Cc: stable-rt@vger.kernel.org
Reported-by: Alexander Gerasiov <gq@cs.msu.su>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
---
 include/linux/hrtimer.h |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -440,7 +440,13 @@ static inline int hrtimer_is_queued(stru
  */
 static inline int hrtimer_callback_running(const struct hrtimer *timer)
 {
-	return timer->base->cpu_base->running == timer;
+	if (timer->base->cpu_base->running == timer)
+		return 1;
+#ifdef CONFIG_PREEMPT_RT_BASE
+	if (timer->base->cpu_base->running_soft == timer)
+		return 1;
+#endif
+	return 0;
 }
 
 /* Forward a hrtimer so it expires after now: */