[PATCH 07/15] thermal: sysfs: lock tz while on policy properties

[Eduardo Valentin]

Serialized calls to tz.ops in user facing
sysfs handler policy_show().
policy_store() is already locked by
the thermal core.

Cc: Zhang Rui <rui.zhang@xxxxxxxxx>
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Eduardo Valentin <edubezval@xxxxxxxxx>
---
 drivers/thermal/thermal_sysfs.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index dcaeb17..234eb18 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -311,8 +311,14 @@ static ssize_t
 policy_show(struct device *dev, struct device_attribute *devattr, char *buf)
 {
 	struct thermal_zone_device *tz = to_thermal_zone(dev);
+	char *name;
 
-	return sprintf(buf, "%s\n", tz->governor->name);
+	/* locking the zone because governor->name does not change */
+	mutex_lock(&tz->lock);
+	name = tz->governor->name;
+	mutex_unlock(&tz->lock);
+
+	return sprintf(buf, "%s\n", name);
 }
 
 static ssize_t
-- 
2.1.4