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/max77650-onkey.c | 129 ++++++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 drivers/input/misc/max77650-onkey.c (limited to 'drivers/input/misc/max77650-onkey.c') diff --git a/drivers/input/misc/max77650-onkey.c b/drivers/input/misc/max77650-onkey.c new file mode 100644 index 000000000..ee55f22db --- /dev/null +++ b/drivers/input/misc/max77650-onkey.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Copyright (C) 2018 BayLibre SAS +// Author: Bartosz Golaszewski +// +// ONKEY driver for MAXIM 77650/77651 charger/power-supply. + +#include +#include +#include +#include +#include +#include +#include + +#define MAX77650_ONKEY_MODE_MASK BIT(3) +#define MAX77650_ONKEY_MODE_PUSH 0x00 +#define MAX77650_ONKEY_MODE_SLIDE BIT(3) + +struct max77650_onkey { + struct input_dev *input; + unsigned int code; +}; + +static irqreturn_t max77650_onkey_falling(int irq, void *data) +{ + struct max77650_onkey *onkey = data; + + input_report_key(onkey->input, onkey->code, 0); + input_sync(onkey->input); + + return IRQ_HANDLED; +} + +static irqreturn_t max77650_onkey_rising(int irq, void *data) +{ + struct max77650_onkey *onkey = data; + + input_report_key(onkey->input, onkey->code, 1); + input_sync(onkey->input); + + return IRQ_HANDLED; +} + +static int max77650_onkey_probe(struct platform_device *pdev) +{ + int irq_r, irq_f, error, mode; + struct max77650_onkey *onkey; + struct device *dev, *parent; + struct regmap *map; + unsigned int type; + + dev = &pdev->dev; + parent = dev->parent; + + map = dev_get_regmap(parent, NULL); + if (!map) + return -ENODEV; + + onkey = devm_kzalloc(dev, sizeof(*onkey), GFP_KERNEL); + if (!onkey) + return -ENOMEM; + + error = device_property_read_u32(dev, "linux,code", &onkey->code); + if (error) + onkey->code = KEY_POWER; + + if (device_property_read_bool(dev, "maxim,onkey-slide")) { + mode = MAX77650_ONKEY_MODE_SLIDE; + type = EV_SW; + } else { + mode = MAX77650_ONKEY_MODE_PUSH; + type = EV_KEY; + } + + error = regmap_update_bits(map, MAX77650_REG_CNFG_GLBL, + MAX77650_ONKEY_MODE_MASK, mode); + if (error) + return error; + + irq_f = platform_get_irq_byname(pdev, "nEN_F"); + if (irq_f < 0) + return irq_f; + + irq_r = platform_get_irq_byname(pdev, "nEN_R"); + if (irq_r < 0) + return irq_r; + + onkey->input = devm_input_allocate_device(dev); + if (!onkey->input) + return -ENOMEM; + + onkey->input->name = "max77650_onkey"; + onkey->input->phys = "max77650_onkey/input0"; + onkey->input->id.bustype = BUS_I2C; + input_set_capability(onkey->input, type, onkey->code); + + error = devm_request_any_context_irq(dev, irq_f, max77650_onkey_falling, + IRQF_ONESHOT, "onkey-down", onkey); + if (error < 0) + return error; + + error = devm_request_any_context_irq(dev, irq_r, max77650_onkey_rising, + IRQF_ONESHOT, "onkey-up", onkey); + if (error < 0) + return error; + + return input_register_device(onkey->input); +} + +static const struct of_device_id max77650_onkey_of_match[] = { + { .compatible = "maxim,max77650-onkey" }, + { } +}; +MODULE_DEVICE_TABLE(of, max77650_onkey_of_match); + +static struct platform_driver max77650_onkey_driver = { + .driver = { + .name = "max77650-onkey", + .of_match_table = max77650_onkey_of_match, + }, + .probe = max77650_onkey_probe, +}; +module_platform_driver(max77650_onkey_driver); + +MODULE_DESCRIPTION("MAXIM 77650/77651 ONKEY driver"); +MODULE_AUTHOR("Bartosz Golaszewski "); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:max77650-onkey"); -- cgit v1.3.1