From 14b2801ccd9ba9ab13dc231e0a4c7cf1dc42d854 Mon Sep 17 00:00:00 2001
From: Lukasz Luba <lukasz.luba@arm.com>
Date: Thu, 22 Apr 2021 16:36:22 +0100
Subject: [PATCH] thermal/core/fair share: Lock the thermal zone while looping
over instances
commit fef05776eb02238dcad8d5514e666a42572c3f32 upstream.
The tz->lock must be hold during the looping over the instances in that
thermal zone. This lock was missing in the governor code since the
beginning, so it's hard to point into a particular commit.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210422153624.6074-2-lukasz.luba@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/thermal/gov_fair_share.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/thermal/gov_fair_share.c b/drivers/thermal/gov_fair_share.c
index aaa07180ab482..645432ce63659 100644
--- a/drivers/thermal/gov_fair_share.c
+++ b/drivers/thermal/gov_fair_share.c
@@ -82,6 +82,8 @@ static int fair_share_throttle(struct thermal_zone_device *tz, int trip)
int total_instance = 0;
int cur_trip_level = get_trip_level(tz);
+ mutex_lock(&tz->lock);
+
list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
if (instance->trip != trip)
continue;
@@ -110,6 +112,8 @@ static int fair_share_throttle(struct thermal_zone_device *tz, int trip)
mutex_unlock(&instance->cdev->lock);
thermal_cdev_update(cdev);
}
+
+ mutex_unlock(&tz->lock);
return 0;
}
--
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