From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- 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