leds: Prevent multiple LED triggers with the same name

Signed-off-by: Adam Nielsen <a.nielsen@shikadi.net>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

drivers/leds/led-triggers.c

@@ -156,12 +156,20 @@ EXPORT_SYMBOL_GPL(led_trigger_set_default);
 int led_trigger_register(struct led_trigger *trigger)
 {
 	struct led_classdev *led_cdev;
+	struct led_trigger *trig;
 
 	rwlock_init(&trigger->leddev_list_lock);
 	INIT_LIST_HEAD(&trigger->led_cdevs);
 
-	/* Add to the list of led triggers */
 	down_write(&triggers_list_lock);
+	/* Make sure the trigger's name isn't already in use */
+	list_for_each_entry(trig, &trigger_list, next_trig) {
+		if (!strcmp(trig->name, trigger->name)) {
+			up_write(&triggers_list_lock);
+			return -EEXIST;
+		}
+	}
+	/* Add to the list of led triggers */
 	list_add_tail(&trigger->next_trig, &trigger_list);
 	up_write(&triggers_list_lock);