[PATCH 1/9] thermal/core: Destroy thermal zone device mutex in release function

[Guenter Roeck]

Accesses to thermal zones, and with it the thermal zone device mutex,
are still possible after the thermal zone device has been unregistered.
For example, thermal_zone_get_temp() can be called from temp_show()
in thermal_sysfs.c if the sysfs attribute was opened before the thermal
device was unregistered.

Move the call to mutex_destroy from thermal_zone_device_unregister()
to thermal_release() to ensure that it is only destroyed after it is
guaranteed to be no longer accessed.

Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
 drivers/thermal/thermal_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 117eeaf7dd24..f548875a016d 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -759,6 +759,7 @@ static void thermal_release(struct device *dev)
 		     sizeof("thermal_zone") - 1)) {
 		tz = to_thermal_zone(dev);
 		thermal_zone_destroy_device_groups(tz);
+		mutex_destroy(&tz->lock);
 		kfree(tz);
 	} else if (!strncmp(dev_name(dev), "cooling_device",
 			    sizeof("cooling_device") - 1)) {
@@ -1390,7 +1391,6 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 	thermal_remove_hwmon_sysfs(tz);
 	ida_free(&thermal_tz_ida, tz->id);
 	ida_destroy(&tz->ida);
-	mutex_destroy(&tz->lock);
 	device_unregister(&tz->device);
 
 	thermal_notify_tz_delete(tz_id);
-- 
2.36.2