From a8df7b1ab70bfd6f261fa5e96985fca638299acc Mon Sep 17 00:00:00 2001 From: Fabio Baltieri Date: Sun, 4 Nov 2012 01:54:34 -0800 Subject: [PATCH] leds: add led_trigger_rename function Implements a "led_trigger_rename" function to rename a trigger with proper locking. This assumes that led name was originally allocated in non-constant storage. Signed-off-by: Fabio Baltieri Cc: Kurt Van Dijck Signed-off-by: Bryan Wu --- drivers/leds/led-triggers.c | 13 +++++++++++++ include/linux/leds.h | 18 ++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c index 262eb4193710..a4fa4bf02d53 100644 --- a/drivers/leds/led-triggers.c +++ b/drivers/leds/led-triggers.c @@ -166,6 +166,19 @@ void led_trigger_set_default(struct led_classdev *led_cdev) } EXPORT_SYMBOL_GPL(led_trigger_set_default); +void led_trigger_rename_static(const char *name, struct led_trigger *trig) +{ + /* new name must be on a temporary string to prevent races */ + BUG_ON(name == trig->name); + + down_write(&triggers_list_lock); + /* this assumes that trig->name was originaly allocated to + * non constant storage */ + strcpy((char *)trig->name, name); + up_write(&triggers_list_lock); +} +EXPORT_SYMBOL_GPL(led_trigger_rename_static); + /* LED Trigger Interface */ int led_trigger_register(struct led_trigger *trig) diff --git a/include/linux/leds.h b/include/linux/leds.h index 6e53bb31c220..8107592cfc41 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -139,6 +139,24 @@ extern void led_blink_set_oneshot(struct led_classdev *led_cdev, extern void led_set_brightness(struct led_classdev *led_cdev, enum led_brightness brightness); +/** + * led_trigger_rename_static - rename a trigger + * @name: the new trigger name + * @trig: the LED trigger to rename + * + * Change a LED trigger name by copying the string passed in + * name into current trigger name, which MUST be large + * enough for the new string. + * + * Note that name must NOT point to the same string used + * during LED registration, as that could lead to races. + * + * This is meant to be used on triggers with statically + * allocated name. + */ +extern void led_trigger_rename_static(const char *name, + struct led_trigger *trig); + /* * LED Triggers */ -- 2.39.5