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 --- net/rfkill/rfkill-gpio.c | 220 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 220 insertions(+) create mode 100644 net/rfkill/rfkill-gpio.c (limited to 'net/rfkill/rfkill-gpio.c') diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c new file mode 100644 index 000000000..9c5b695db --- /dev/null +++ b/net/rfkill/rfkill-gpio.c @@ -0,0 +1,220 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2011, NVIDIA Corporation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct rfkill_gpio_data { + const char *name; + enum rfkill_type type; + struct gpio_desc *reset_gpio; + struct gpio_desc *shutdown_gpio; + + struct rfkill *rfkill_dev; + struct clk *clk; + + bool clk_enabled; +}; + +static int rfkill_gpio_set_power(void *data, bool blocked) +{ + struct rfkill_gpio_data *rfkill = data; + + if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled) { + int ret = clk_enable(rfkill->clk); + + if (ret) + return ret; + } + + gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked); + gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked); + + if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled) + clk_disable(rfkill->clk); + + rfkill->clk_enabled = !blocked; + + return 0; +} + +static const struct rfkill_ops rfkill_gpio_ops = { + .set_block = rfkill_gpio_set_power, +}; + +static const struct acpi_gpio_params reset_gpios = { 0, 0, false }; +static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false }; + +static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = { + { "reset-gpios", &reset_gpios, 1 }, + { "shutdown-gpios", &shutdown_gpios, 1 }, + { }, +}; + +static int rfkill_gpio_acpi_probe(struct device *dev, + struct rfkill_gpio_data *rfkill) +{ + const struct acpi_device_id *id; + + id = acpi_match_device(dev->driver->acpi_match_table, dev); + if (!id) + return -ENODEV; + + rfkill->type = (unsigned)id->driver_data; + + return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios); +} + +/* List of DMI matches for devices on which rfkill-gpio should not load, + * to avoid firmware bugs. + */ +static const struct dmi_system_id rfkill_gpio_deny_table[] = { + { + /* Lenovo Yoga Tab 3 Pro YT3-X90, bogus "BCM4752" device in DSDT */ + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Intel Corporation"), + DMI_MATCH(DMI_PRODUCT_VERSION, "Blade3-10A-001"), + }, + }, + { } +}; + +static int rfkill_gpio_probe(struct platform_device *pdev) +{ + struct rfkill_gpio_data *rfkill; + const char *type_name = NULL; + const char *name_property; + const char *type_property; + struct gpio_desc *gpio; + int ret; + + if (dmi_check_system(rfkill_gpio_deny_table)) + return -ENODEV; + + rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL); + if (!rfkill) + return -ENOMEM; + + if (dev_of_node(&pdev->dev)) { + name_property = "label"; + type_property = "radio-type"; + } else { + name_property = "name"; + type_property = "type"; + } + device_property_read_string(&pdev->dev, name_property, &rfkill->name); + device_property_read_string(&pdev->dev, type_property, &type_name); + + if (!rfkill->name) + rfkill->name = dev_name(&pdev->dev); + + rfkill->type = rfkill_find_type(type_name); + + if (ACPI_HANDLE(&pdev->dev)) { + ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill); + if (ret) + return ret; + } + + rfkill->clk = devm_clk_get(&pdev->dev, NULL); + + gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_ASIS); + if (IS_ERR(gpio)) + return PTR_ERR(gpio); + + rfkill->reset_gpio = gpio; + + gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_ASIS); + if (IS_ERR(gpio)) + return PTR_ERR(gpio); + + rfkill->shutdown_gpio = gpio; + + /* Make sure at-least one GPIO is defined for this instance */ + if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) { + dev_err(&pdev->dev, "invalid platform data\n"); + return -EINVAL; + } + + ret = gpiod_direction_output(rfkill->reset_gpio, true); + if (ret) + return ret; + + ret = gpiod_direction_output(rfkill->shutdown_gpio, true); + if (ret) + return ret; + + rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev, + rfkill->type, &rfkill_gpio_ops, + rfkill); + if (!rfkill->rfkill_dev) + return -ENOMEM; + + if (device_property_present(&pdev->dev, "default-blocked")) + rfkill_init_sw_state(rfkill->rfkill_dev, true); + + ret = rfkill_register(rfkill->rfkill_dev); + if (ret < 0) + goto err_destroy; + + platform_set_drvdata(pdev, rfkill); + + dev_info(&pdev->dev, "%s device registered.\n", rfkill->name); + + return 0; + +err_destroy: + rfkill_destroy(rfkill->rfkill_dev); + + return ret; +} + +static void rfkill_gpio_remove(struct platform_device *pdev) +{ + struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev); + + rfkill_unregister(rfkill->rfkill_dev); + rfkill_destroy(rfkill->rfkill_dev); +} + +#ifdef CONFIG_ACPI +static const struct acpi_device_id rfkill_acpi_match[] = { + { "BCM4752", RFKILL_TYPE_GPS }, + { "LNV4752", RFKILL_TYPE_GPS }, + { }, +}; +MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match); +#endif + +static const struct of_device_id rfkill_of_match[] __maybe_unused = { + { .compatible = "rfkill-gpio", }, + { }, +}; +MODULE_DEVICE_TABLE(of, rfkill_of_match); + +static struct platform_driver rfkill_gpio_driver = { + .probe = rfkill_gpio_probe, + .remove = rfkill_gpio_remove, + .driver = { + .name = "rfkill_gpio", + .acpi_match_table = ACPI_PTR(rfkill_acpi_match), + .of_match_table = of_match_ptr(rfkill_of_match), + }, +}; + +module_platform_driver(rfkill_gpio_driver); + +MODULE_DESCRIPTION("gpio rfkill"); +MODULE_AUTHOR("NVIDIA"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1