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/mfd/rohm-pwrbutton.c | 112 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 drivers/mfd/rohm-pwrbutton.c (limited to 'drivers/mfd/rohm-pwrbutton.c') diff --git a/drivers/mfd/rohm-pwrbutton.c b/drivers/mfd/rohm-pwrbutton.c new file mode 100644 index 000000000..96a6d1f01 --- /dev/null +++ b/drivers/mfd/rohm-pwrbutton.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Shared helper for ROHM PMIC power button registration + * + * Copyright 2018, 2019 ROHM Semiconductors + * Copyright 2026 Google LLC + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "rohm-pwrbutton.h" + +#define GPIO_KEYS 0 /* Node corresponding to gpio-keys device itself */ +#define PWRON_KEY 1 /* Node describing power button in gpio-keys */ + +static int rohm_pwrbutton_register_swnodes(const struct software_node *nodes) +{ + const struct software_node * const node_group[] = { + &nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL + }; + + return software_node_register_node_group(node_group); +} + +static void rohm_pwrbutton_unregister_swnodes(void *data) +{ + const struct software_node *nodes = data; + const struct software_node * const node_group[] = { + &nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL + }; + + software_node_unregister_node_group(node_group); +} + +int rohm_register_pwrbutton(struct device *dev, int irq, const char *name, + bool wakeup, struct irq_domain *irq_domain) +{ + const struct resource res[] = { + DEFINE_RES_IRQ_NAMED(irq, name), + }; + struct mfd_cell gpio_keys_cell = { + .name = "gpio-keys", + .resources = res, + .num_resources = ARRAY_SIZE(res), + }; + struct property_entry *parent_props; + struct property_entry *child_props; + struct software_node *nodes; + int n_props; + int ret; + + if (irq <= 0) + return -EINVAL; + + nodes = devm_kcalloc(dev, 2, sizeof(*nodes), GFP_KERNEL); + if (!nodes) + return -ENOMEM; + + nodes[GPIO_KEYS].name = devm_kasprintf(dev, GFP_KERNEL, "%s-power-key", dev_name(dev)); + if (!nodes[GPIO_KEYS].name) + return -ENOMEM; + + parent_props = devm_kcalloc(dev, 2, sizeof(*parent_props), GFP_KERNEL); + if (!parent_props) + return -ENOMEM; + + parent_props[0] = PROPERTY_ENTRY_STRING("label", name); + nodes[GPIO_KEYS].properties = parent_props; + + n_props = 2; /* linux,code and terminator */ + if (wakeup) + n_props++; + + child_props = devm_kcalloc(dev, n_props, sizeof(*child_props), GFP_KERNEL); + if (!child_props) + return -ENOMEM; + + child_props[0] = PROPERTY_ENTRY_U32("linux,code", KEY_POWER); + if (wakeup) + child_props[1] = PROPERTY_ENTRY_BOOL("wakeup-source"); + + nodes[PWRON_KEY].parent = &nodes[GPIO_KEYS]; + nodes[PWRON_KEY].properties = child_props; + + ret = rohm_pwrbutton_register_swnodes(nodes); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, rohm_pwrbutton_unregister_swnodes, nodes); + if (ret) + return ret; + + gpio_keys_cell.swnode = &nodes[GPIO_KEYS]; + + ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, &gpio_keys_cell, 1, + NULL, 0, irq_domain); + if (ret) + return dev_err_probe(dev, ret, "Failed to register power-button"); + + return 0; +} +EXPORT_SYMBOL_GPL(rohm_register_pwrbutton); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Dmitry Torokhov "); +MODULE_DESCRIPTION("Shared helper for ROHM PMIC power button registration"); -- cgit v1.3.1