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/misc/e3x0-button.c | 135 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 135 insertions(+) create mode 100644 drivers/input/misc/e3x0-button.c (limited to 'drivers/input/misc/e3x0-button.c') diff --git a/drivers/input/misc/e3x0-button.c b/drivers/input/misc/e3x0-button.c new file mode 100644 index 000000000..5bd527117 --- /dev/null +++ b/drivers/input/misc/e3x0-button.c @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2014, National Instruments Corp. All rights reserved. + * + * Driver for NI Ettus Research USRP E3x0 Button Driver + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +static irqreturn_t e3x0_button_release_handler(int irq, void *data) +{ + struct input_dev *idev = data; + + input_report_key(idev, KEY_POWER, 0); + input_sync(idev); + + return IRQ_HANDLED; +} + +static irqreturn_t e3x0_button_press_handler(int irq, void *data) +{ + struct input_dev *idev = data; + + input_report_key(idev, KEY_POWER, 1); + pm_wakeup_event(idev->dev.parent, 0); + input_sync(idev); + + return IRQ_HANDLED; +} + +static int e3x0_button_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + + if (device_may_wakeup(dev)) + enable_irq_wake(platform_get_irq_byname(pdev, "press")); + + return 0; +} + +static int e3x0_button_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + + if (device_may_wakeup(dev)) + disable_irq_wake(platform_get_irq_byname(pdev, "press")); + + return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(e3x0_button_pm_ops, + e3x0_button_suspend, e3x0_button_resume); + +static int e3x0_button_probe(struct platform_device *pdev) +{ + struct input_dev *input; + int irq_press, irq_release; + int error; + + irq_press = platform_get_irq_byname(pdev, "press"); + if (irq_press < 0) + return irq_press; + + irq_release = platform_get_irq_byname(pdev, "release"); + if (irq_release < 0) + return irq_release; + + input = devm_input_allocate_device(&pdev->dev); + if (!input) + return -ENOMEM; + + input->name = "NI Ettus Research USRP E3x0 Button Driver"; + input->phys = "e3x0_button/input0"; + input->dev.parent = &pdev->dev; + + input_set_capability(input, EV_KEY, KEY_POWER); + + error = devm_request_irq(&pdev->dev, irq_press, + e3x0_button_press_handler, 0, + "e3x0-button", input); + if (error) { + dev_err(&pdev->dev, "Failed to request 'press' IRQ#%d: %d\n", + irq_press, error); + return error; + } + + error = devm_request_irq(&pdev->dev, irq_release, + e3x0_button_release_handler, 0, + "e3x0-button", input); + if (error) { + dev_err(&pdev->dev, "Failed to request 'release' IRQ#%d: %d\n", + irq_release, error); + return error; + } + + error = input_register_device(input); + if (error) { + dev_err(&pdev->dev, "Can't register input device: %d\n", error); + return error; + } + + device_init_wakeup(&pdev->dev, 1); + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id e3x0_button_match[] = { + { .compatible = "ettus,e3x0-button", }, + { } +}; +MODULE_DEVICE_TABLE(of, e3x0_button_match); +#endif + +static struct platform_driver e3x0_button_driver = { + .driver = { + .name = "e3x0-button", + .of_match_table = of_match_ptr(e3x0_button_match), + .pm = pm_sleep_ptr(&e3x0_button_pm_ops), + }, + .probe = e3x0_button_probe, +}; + +module_platform_driver(e3x0_button_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Moritz Fischer "); +MODULE_DESCRIPTION("NI Ettus Research USRP E3x0 Button driver"); +MODULE_ALIAS("platform:e3x0-button"); -- cgit v1.3.1