From 20739a07f1d3609e5c01cafc720454a07c858660 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Sat, 14 Sep 2024 14:37:00 +0000 Subject: [PATCH] Revert "leds: trigger: Remove unused function led_trigger_rename_static()" This reverts commit b4e147d3f1fe835c9d9334c7eab83c21ff2d0149 which is commit c82a1662d4548c454de5343b88f69b9fc82266b3 upstream. It breaks the Android kernel abi and can be brought back in the future in an abi-safe way if it is really needed. Bug: 161946584 Change-Id: Iea8ece3b5c88a97395e25c2ba7a512872a81e93f Signed-off-by: Greg Kroah-Hartman --- drivers/leds/led-triggers.c | 13 +++++++++++++ include/linux/leds.h | 17 +++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c index dddfc301d341..024b73f84ce0 100644 --- a/drivers/leds/led-triggers.c +++ b/drivers/leds/led-triggers.c @@ -268,6 +268,19 @@ 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 2bbff7519b73..ba4861ec73d3 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -409,6 +409,23 @@ static inline void *led_get_trigger_data(struct led_classdev *led_cdev) return led_cdev->trigger_data; } +/** + * 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. + */ +void led_trigger_rename_static(const char *name, struct led_trigger *trig); + #define module_led_trigger(__led_trigger) \ module_driver(__led_trigger, led_trigger_register, \ led_trigger_unregister)