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/dax/bus.h | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 drivers/dax/bus.h (limited to 'drivers/dax/bus.h') diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h new file mode 100644 index 000000000..bfc31923f --- /dev/null +++ b/drivers/dax/bus.h @@ -0,0 +1,81 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */ +#ifndef __DAX_BUS_H__ +#define __DAX_BUS_H__ +#include +#include +#include +#include + +struct dev_dax; +struct resource; +struct dax_device; +struct dax_region; + +/* dax bus specific ioresource flags */ +#define IORESOURCE_DAX_STATIC BIT(0) +#define IORESOURCE_DAX_KMEM BIT(1) + +#define DAX_KMEM_UNPLUGGED (-1) /* Do not create memory blocks */ + +struct dax_region *alloc_dax_region(struct device *parent, int region_id, + struct range *range, int target_node, unsigned int align, + unsigned long flags); + +struct dev_dax_data { + struct dax_region *dax_region; + struct dev_pagemap *pgmap; + resource_size_t size; + int id; + bool memmap_on_memory; +}; + +struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data); + +enum dax_driver_type { + DAXDRV_KMEM_TYPE, + DAXDRV_DEVICE_TYPE, + DAXDRV_FSDEV_TYPE, +}; + +struct dax_device_driver { + struct device_driver drv; + struct list_head ids; + enum dax_driver_type type; + int (*probe)(struct dev_dax *dev); + void (*remove)(struct dev_dax *dev); +}; + +#define to_dax_drv(__drv) container_of_const(__drv, struct dax_device_driver, drv) + +int __dax_driver_register(struct dax_device_driver *dax_drv, + struct module *module, const char *mod_name); +#define dax_driver_register(driver) \ + __dax_driver_register(driver, THIS_MODULE, KBUILD_MODNAME) +void dax_driver_unregister(struct dax_device_driver *dax_drv); +void kill_dev_dax(struct dev_dax *dev_dax); +bool static_dev_dax(struct dev_dax *dev_dax); + +struct hmem_platform_device { + struct platform_device pdev; + struct work_struct work; + bool did_probe; +}; + +static inline struct hmem_platform_device * +to_hmem_platform_device(struct platform_device *pdev) +{ + return container_of(pdev, struct hmem_platform_device, pdev); +} + +#if IS_ENABLED(CONFIG_DEV_DAX_HMEM) +void dax_hmem_flush_work(void); +#else +static inline void dax_hmem_flush_work(void) { } +#endif + +#define MODULE_ALIAS_DAX_DEVICE(type) \ + MODULE_ALIAS("dax:t" __stringify(type) "*") +#define DAX_DEVICE_MODALIAS_FMT "dax:t%d" + +#endif /* __DAX_BUS_H__ */ -- cgit v1.3.1