From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 14 Dec 2017 11:31:40 +0100
Subject: hrtimer: account for migrated timers
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: 1d7f05200a781749e3176718b8f0ae4d337b71ba
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension

if the timer is enqueud on CPUX and we run on CPUY then we have to
cpu_base bits of the correct CPU. Not sure if this accounts for all the
pieces but it might be okay with the check we have in
hrtimer_check_target() (that we have nothing to do but just wait).

Reported-by: bert schulze <spambemyguest@googlemail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
---
 kernel/time/hrtimer.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -800,16 +800,18 @@ static void hrtimer_reprogram(struct hrt
 		expires = 0;
 
 	if (timer->is_soft) {
-		if (cpu_base->softirq_activated)
+		struct hrtimer_cpu_base *timer_cpu_base = base->cpu_base;
+
+		if (timer_cpu_base->softirq_activated)
 			return;
 
-		if (!ktime_before(expires, cpu_base->softirq_expires_next))
+		if (!ktime_before(expires, timer_cpu_base->softirq_expires_next))
 			return;
 
-		cpu_base->softirq_next_timer = timer;
-		cpu_base->softirq_expires_next = expires;
+		timer_cpu_base->softirq_next_timer = timer;
+		timer_cpu_base->softirq_expires_next = expires;
 
-		if (!ktime_before(expires, cpu_base->expires_next) ||
+		if (!ktime_before(expires, timer_cpu_base->expires_next) ||
 		    !reprogram)
 			return;
 	}