thermal/core: Destroy thermal zone device mutex in release function

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@roeck-us.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index e0ca631ac4c8feb77e03941f9fcc9f216fc2f717..b31d3247667258a7b624c9836fb0d9fcce405131 100644 (file)
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -754,6 +754,7 @@ 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);