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/cpcap-pwrbutton.c | 112 +++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 drivers/input/misc/cpcap-pwrbutton.c (limited to 'drivers/input/misc/cpcap-pwrbutton.c') diff --git a/drivers/input/misc/cpcap-pwrbutton.c b/drivers/input/misc/cpcap-pwrbutton.c new file mode 100644 index 000000000..85cddb847 --- /dev/null +++ b/drivers/input/misc/cpcap-pwrbutton.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * CPCAP Power Button Input Driver + * + * Copyright (C) 2017 Sebastian Reichel + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define CPCAP_IRQ_ON 23 +#define CPCAP_IRQ_ON_BITMASK (1 << (CPCAP_IRQ_ON % 16)) + +struct cpcap_power_button { + struct regmap *regmap; + struct input_dev *idev; + struct device *dev; +}; + +static irqreturn_t powerbutton_irq(int irq, void *_button) +{ + struct cpcap_power_button *button = _button; + int val; + + val = cpcap_sense_virq(button->regmap, irq); + if (val < 0) { + dev_err(button->dev, "irq read failed: %d", val); + return IRQ_HANDLED; + } + + pm_wakeup_event(button->dev, 0); + input_report_key(button->idev, KEY_POWER, val); + input_sync(button->idev); + + return IRQ_HANDLED; +} + +static int cpcap_power_button_probe(struct platform_device *pdev) +{ + struct cpcap_power_button *button; + int irq; + int err; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + button = devm_kmalloc(&pdev->dev, sizeof(*button), GFP_KERNEL); + if (!button) + return -ENOMEM; + + button->idev = devm_input_allocate_device(&pdev->dev); + if (!button->idev) + return -ENOMEM; + + button->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!button->regmap) + return -ENODEV; + + button->dev = &pdev->dev; + + button->idev->name = "cpcap-pwrbutton"; + button->idev->phys = "cpcap-pwrbutton/input0"; + input_set_capability(button->idev, EV_KEY, KEY_POWER); + + err = devm_request_threaded_irq(&pdev->dev, irq, NULL, + powerbutton_irq, IRQF_ONESHOT, "cpcap_pwrbutton", button); + if (err < 0) { + dev_err(&pdev->dev, "IRQ request failed: %d\n", err); + return err; + } + + err = input_register_device(button->idev); + if (err) { + dev_err(&pdev->dev, "Input register failed: %d\n", err); + return err; + } + + device_init_wakeup(&pdev->dev, true); + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id cpcap_pwrbutton_dt_match_table[] = { + { .compatible = "motorola,cpcap-pwrbutton" }, + {}, +}; +MODULE_DEVICE_TABLE(of, cpcap_pwrbutton_dt_match_table); +#endif + +static struct platform_driver cpcap_power_button_driver = { + .probe = cpcap_power_button_probe, + .driver = { + .name = "cpcap-pwrbutton", + .of_match_table = of_match_ptr(cpcap_pwrbutton_dt_match_table), + }, +}; +module_platform_driver(cpcap_power_button_driver); + +MODULE_ALIAS("platform:cpcap-pwrbutton"); +MODULE_DESCRIPTION("CPCAP Power Button"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Sebastian Reichel "); -- cgit v1.3.1