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/tps6594-pwrbutton.c | 126 +++++++++++++++++++++++++++++++++ 1 file changed, 126 insertions(+) create mode 100644 drivers/input/misc/tps6594-pwrbutton.c (limited to 'drivers/input/misc/tps6594-pwrbutton.c') diff --git a/drivers/input/misc/tps6594-pwrbutton.c b/drivers/input/misc/tps6594-pwrbutton.c new file mode 100644 index 000000000..cd039b386 --- /dev/null +++ b/drivers/input/misc/tps6594-pwrbutton.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * power button driver for TI TPS6594 PMICs + * + * Copyright (C) 2025 Critical Link LLC - https://www.criticallink.com/ + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct tps6594_pwrbutton { + struct device *dev; + struct input_dev *idev; + char phys[32]; +}; + +static irqreturn_t tps6594_pb_push_irq(int irq, void *_pwr) +{ + struct tps6594_pwrbutton *pwr = _pwr; + + input_report_key(pwr->idev, KEY_POWER, 1); + pm_wakeup_event(pwr->dev, 0); + input_sync(pwr->idev); + + return IRQ_HANDLED; +} + +static irqreturn_t tps6594_pb_release_irq(int irq, void *_pwr) +{ + struct tps6594_pwrbutton *pwr = _pwr; + + input_report_key(pwr->idev, KEY_POWER, 0); + input_sync(pwr->idev); + + return IRQ_HANDLED; +} + +static int tps6594_pb_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct tps6594_pwrbutton *pwr; + struct input_dev *idev; + int error; + int push_irq; + int release_irq; + + pwr = devm_kzalloc(dev, sizeof(*pwr), GFP_KERNEL); + if (!pwr) + return -ENOMEM; + + idev = devm_input_allocate_device(dev); + if (!idev) + return -ENOMEM; + + idev->name = pdev->name; + snprintf(pwr->phys, sizeof(pwr->phys), "%s/input0", + pdev->name); + idev->phys = pwr->phys; + idev->id.bustype = BUS_I2C; + + input_set_capability(idev, EV_KEY, KEY_POWER); + + pwr->dev = dev; + pwr->idev = idev; + device_init_wakeup(dev, true); + + push_irq = platform_get_irq(pdev, 0); + if (push_irq < 0) + return -EINVAL; + + release_irq = platform_get_irq(pdev, 1); + if (release_irq < 0) + return -EINVAL; + + error = devm_request_threaded_irq(dev, push_irq, NULL, + tps6594_pb_push_irq, + IRQF_ONESHOT, + pdev->resource[0].name, pwr); + if (error) { + dev_err(dev, "failed to request push IRQ #%d: %d\n", push_irq, + error); + return error; + } + + error = devm_request_threaded_irq(dev, release_irq, NULL, + tps6594_pb_release_irq, + IRQF_ONESHOT, + pdev->resource[1].name, pwr); + if (error) { + dev_err(dev, "failed to request release IRQ #%d: %d\n", + release_irq, error); + return error; + } + + error = input_register_device(idev); + if (error) { + dev_err(dev, "Can't register power button: %d\n", error); + return error; + } + + return 0; +} + +static const struct platform_device_id tps6594_pwrbtn_id_table[] = { + { "tps6594-pwrbutton", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(platform, tps6594_pwrbtn_id_table); + +static struct platform_driver tps6594_pb_driver = { + .probe = tps6594_pb_probe, + .driver = { + .name = "tps6594_pwrbutton", + }, + .id_table = tps6594_pwrbtn_id_table, +}; +module_platform_driver(tps6594_pb_driver); + +MODULE_DESCRIPTION("TPS6594 Power Button"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1