cfg80211: fix race between sysfs and cfg80211

[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / leds / led-triggers.c

diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index f910eaf..f1c00db 100644 (file)
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -21,6 +21,7 @@
 #include <linux/timer.h>
 #include <linux/rwsem.h>
 #include <linux/leds.h>
+#include <linux/slab.h>
 #include "leds.h"
 
 /*
@@ -156,12 +157,20 @@ 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);