[BACKPORT 4.14.y 6/8] sched/cpufreq/schedutil: Fix error path mutex unlock

[Arnd Bergmann]

From: Jules Maselbas <jules.maselbas@xxxxxxx>

This patch prevents the 'global_tunables_lock' mutex from being
unlocked before being locked.  This mutex is not locked if the
sugov_kthread_create() function fails.

Signed-off-by: Jules Maselbas <jules.maselbas@xxxxxxx>
Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Chris Redpath <chris.redpath@xxxxxxx>
Cc: Dietmar Eggermann <dietmar.eggemann@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Patrick Bellasi <patrick.bellasi@xxxxxxx>
Cc: Stephen Kyle <stephen.kyle@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: nd@xxxxxxx
Link: http://lkml.kernel.org/r/20180329144301.38419-1-jules.maselbas@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
(cherry picked from commit 1b5d43cfb69759d8ef8d30469cea31d0c037aed5)
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 kernel/sched/cpufreq_schedutil.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 81eb7899c7c8..b314c9eaa71d 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -605,10 +605,9 @@ static int sugov_init(struct cpufreq_policy *policy)
 
 stop_kthread:
 	sugov_kthread_stop(sg_policy);
-
-free_sg_policy:
 	mutex_unlock(&global_tunables_lock);
 
+free_sg_policy:
 	sugov_policy_free(sg_policy);
 
 disable_fast_switch:
-- 
2.20.0