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/siox/siox.h | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 drivers/siox/siox.h (limited to 'drivers/siox/siox.h') diff --git a/drivers/siox/siox.h b/drivers/siox/siox.h new file mode 100644 index 000000000..513f2c831 --- /dev/null +++ b/drivers/siox/siox.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2015-2017 Pengutronix, Uwe Kleine-König + */ +#include +#include +#include + +#define to_siox_master(_dev) container_of((_dev), struct siox_master, dev) +struct siox_master { + /* these fields should be initialized by the driver */ + int busno; + int (*pushpull)(struct siox_master *smaster, + size_t setbuf_len, const u8 setbuf[], + size_t getbuf_len, u8 getbuf[]); + + /* might be initialized by the driver, if 0 it is set to HZ / 40 */ + unsigned long poll_interval; /* in jiffies */ + + /* framework private stuff */ + struct mutex lock; + bool active; + struct module *owner; + struct device dev; + unsigned int num_devices; + struct list_head devices; + + size_t setbuf_len, getbuf_len; + size_t buf_len; + u8 *buf; + u8 status; + + unsigned long last_poll; + struct task_struct *poll_thread; +}; + +static inline void *siox_master_get_devdata(struct siox_master *smaster) +{ + return dev_get_drvdata(&smaster->dev); +} + +struct siox_master *siox_master_alloc(struct device *dev, size_t size); +static inline void siox_master_put(struct siox_master *smaster) +{ + put_device(&smaster->dev); +} + +struct siox_master *devm_siox_master_alloc(struct device *dev, size_t size); + +int siox_master_register(struct siox_master *smaster); +void siox_master_unregister(struct siox_master *smaster); + +int devm_siox_master_register(struct device *dev, struct siox_master *smaster); -- cgit v1.3.1