From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/input/input-leds.c | 226 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 226 insertions(+) create mode 100644 drivers/input/input-leds.c (limited to 'drivers/input/input-leds.c') diff --git a/drivers/input/input-leds.c b/drivers/input/input-leds.c new file mode 100644 index 000000000..b08d1d08d --- /dev/null +++ b/drivers/input/input-leds.c @@ -0,0 +1,226 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * LED support for the input layer + * + * Copyright 2010-2015 Samuel Thibault + */ + +#include +#include +#include +#include +#include +#include + +#if IS_ENABLED(CONFIG_VT) +#define VT_TRIGGER(_name) .trigger = _name +#else +#define VT_TRIGGER(_name) .trigger = NULL +#endif + +#if IS_ENABLED(CONFIG_SND_CTL_LED) +#define AUDIO_TRIGGER(_name) .trigger = _name +#else +#define AUDIO_TRIGGER(_name) .trigger = NULL +#endif + +static const struct { + const char *name; + const char *trigger; +} input_led_info[LED_CNT] = { + [LED_NUML] = { "numlock", VT_TRIGGER("kbd-numlock") }, + [LED_CAPSL] = { "capslock", VT_TRIGGER("kbd-capslock") }, + [LED_SCROLLL] = { "scrolllock", VT_TRIGGER("kbd-scrolllock") }, + [LED_COMPOSE] = { "compose" }, + [LED_KANA] = { "kana", VT_TRIGGER("kbd-kanalock") }, + [LED_SLEEP] = { "sleep" } , + [LED_SUSPEND] = { "suspend" }, + [LED_MUTE] = { "mute", AUDIO_TRIGGER("audio-mute") }, + [LED_MISC] = { "misc" }, + [LED_MAIL] = { "mail" }, + [LED_CHARGING] = { "charging" }, +}; + +struct input_led { + struct led_classdev cdev; + struct input_handle *handle; + unsigned int code; /* One of LED_* constants */ +}; + +struct input_leds { + struct input_handle handle; + unsigned int num_leds; + struct input_led leds[] __counted_by(num_leds); +}; + +static enum led_brightness input_leds_brightness_get(struct led_classdev *cdev) +{ + struct input_led *led = container_of(cdev, struct input_led, cdev); + struct input_dev *input = led->handle->dev; + + return test_bit(led->code, input->led) ? cdev->max_brightness : 0; +} + +static void input_leds_brightness_set(struct led_classdev *cdev, + enum led_brightness brightness) +{ + struct input_led *led = container_of(cdev, struct input_led, cdev); + + input_inject_event(led->handle, EV_LED, led->code, !!brightness); +} + +static void input_leds_event(struct input_handle *handle, unsigned int type, + unsigned int code, int value) +{ +} + +static int input_leds_get_count(struct input_dev *dev) +{ + unsigned int led_code; + int count = 0; + + for_each_set_bit(led_code, dev->ledbit, LED_CNT) + if (input_led_info[led_code].name) + count++; + + return count; +} + +static int input_leds_connect(struct input_handler *handler, + struct input_dev *dev, + const struct input_device_id *id) +{ + struct input_leds *leds; + struct input_led *led; + unsigned int num_leds; + unsigned int led_code; + int led_no; + int error; + + num_leds = input_leds_get_count(dev); + if (!num_leds) + return -ENXIO; + + leds = kzalloc_flex(*leds, leds, num_leds); + if (!leds) + return -ENOMEM; + + leds->num_leds = num_leds; + + leds->handle.dev = dev; + leds->handle.handler = handler; + leds->handle.name = "leds"; + leds->handle.private = leds; + + error = input_register_handle(&leds->handle); + if (error) + goto err_free_mem; + + error = input_open_device(&leds->handle); + if (error) + goto err_unregister_handle; + + led_no = 0; + for_each_set_bit(led_code, dev->ledbit, LED_CNT) { + if (!input_led_info[led_code].name) + continue; + + led = &leds->leds[led_no]; + led->handle = &leds->handle; + led->code = led_code; + + led->cdev.name = kasprintf(GFP_KERNEL, "%s::%s", + dev_name(&dev->dev), + input_led_info[led_code].name); + if (!led->cdev.name) { + error = -ENOMEM; + goto err_unregister_leds; + } + + led->cdev.max_brightness = 1; + led->cdev.brightness_get = input_leds_brightness_get; + led->cdev.brightness_set = input_leds_brightness_set; + led->cdev.default_trigger = input_led_info[led_code].trigger; + + error = led_classdev_register(&dev->dev, &led->cdev); + if (error) { + dev_err(&dev->dev, "failed to register LED %s: %d\n", + led->cdev.name, error); + kfree(led->cdev.name); + goto err_unregister_leds; + } + + led_no++; + } + + return 0; + +err_unregister_leds: + while (--led_no >= 0) { + struct input_led *led = &leds->leds[led_no]; + + led_classdev_unregister(&led->cdev); + kfree(led->cdev.name); + } + + input_close_device(&leds->handle); + +err_unregister_handle: + input_unregister_handle(&leds->handle); + +err_free_mem: + kfree(leds); + return error; +} + +static void input_leds_disconnect(struct input_handle *handle) +{ + struct input_leds *leds = handle->private; + int i; + + for (i = 0; i < leds->num_leds; i++) { + struct input_led *led = &leds->leds[i]; + + led_classdev_unregister(&led->cdev); + kfree(led->cdev.name); + } + + input_close_device(handle); + input_unregister_handle(handle); + + kfree(leds); +} + +static const struct input_device_id input_leds_ids[] = { + { + .flags = INPUT_DEVICE_ID_MATCH_EVBIT, + .evbit = { BIT_MASK(EV_LED) }, + }, + { }, +}; +MODULE_DEVICE_TABLE(input, input_leds_ids); + +static struct input_handler input_leds_handler = { + .event = input_leds_event, + .connect = input_leds_connect, + .disconnect = input_leds_disconnect, + .name = "leds", + .id_table = input_leds_ids, +}; + +static int __init input_leds_init(void) +{ + return input_register_handler(&input_leds_handler); +} +module_init(input_leds_init); + +static void __exit input_leds_exit(void) +{ + input_unregister_handler(&input_leds_handler); +} +module_exit(input_leds_exit); + +MODULE_AUTHOR("Samuel Thibault "); +MODULE_AUTHOR("Dmitry Torokhov "); +MODULE_DESCRIPTION("Input -> LEDs Bridge"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1