[PATCH] cpufreq: schedutil: Prevent unnecessary mutex unlock

[PATCH] cpufreq: schedutil: Prevent unnecessary mutex unlock

[Jules Maselbas]

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

Signed-off-by: Jules Maselbas <jules.maselbas@arm.com>
---
 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 7936f548e071..617c6741c525 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -625,10 +625,9 @@ 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:
-- 
2.16.2

[tip:sched/urgent] sched/cpufreq/schedutil: Fix error path mutex unlock

[tip-bot for Jules Maselbas]

Commit-ID:  1b5d43cfb69759d8ef8d30469cea31d0c037aed5
Gitweb:     https://git.kernel.org/tip/1b5d43cfb69759d8ef8d30469cea31d0c037aed5
Author:     Jules Maselbas <jules.maselbas@arm.com>
AuthorDate: Thu, 29 Mar 2018 15:43:01 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Sat, 31 Mar 2018 20:42:38 +0200

sched/cpufreq/schedutil: Fix error path mutex unlock

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@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Redpath <chris.redpath@arm.com>
Cc: Dietmar Eggermann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Patrick Bellasi <patrick.bellasi@arm.com>
Cc: Stephen Kyle <stephen.kyle@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: nd@arm.com
Link: http://lkml.kernel.org/r/20180329144301.38419-1-jules.maselbas@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 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 7936f548e071..617c6741c525 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -625,10 +625,9 @@ fail:
 
 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: