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/comedi/comedi_internal.h | 86 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 drivers/comedi/comedi_internal.h (limited to 'drivers/comedi/comedi_internal.h') diff --git a/drivers/comedi/comedi_internal.h b/drivers/comedi/comedi_internal.h new file mode 100644 index 000000000..41a3b09f8 --- /dev/null +++ b/drivers/comedi/comedi_internal.h @@ -0,0 +1,86 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _COMEDI_INTERNAL_H +#define _COMEDI_INTERNAL_H + +#include +#include + +/* + * various internal comedi stuff + */ + +struct comedi_buf_map; +struct comedi_devconfig; +struct comedi_device; +struct comedi_insn; +struct comedi_rangeinfo; +struct comedi_subdevice; +struct device; + +int do_rangeinfo_ioctl(struct comedi_device *dev, + struct comedi_rangeinfo *it); +struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device); +void comedi_release_hardware_device(struct device *hardware_device); +int comedi_alloc_subdevice_minor(struct comedi_subdevice *s); +void comedi_free_subdevice_minor(struct comedi_subdevice *s); + +int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s, + unsigned long new_size); +void comedi_buf_reset(struct comedi_subdevice *s); +bool comedi_buf_is_mmapped(struct comedi_subdevice *s); +void comedi_buf_map_get(struct comedi_buf_map *bm); +int comedi_buf_map_put(struct comedi_buf_map *bm); +int comedi_buf_map_access(struct comedi_buf_map *bm, unsigned long offset, + void *buf, int len, int write); +struct comedi_buf_map * +comedi_buf_map_from_subdev_get(struct comedi_subdevice *s); +unsigned int comedi_buf_write_n_available(struct comedi_subdevice *s); +unsigned int comedi_buf_write_n_allocated(struct comedi_subdevice *s); +unsigned int _comedi_buf_write_alloc(struct comedi_subdevice *s, + unsigned int nbytes); +unsigned int _comedi_buf_write_free(struct comedi_subdevice *s, + unsigned int nbytes); +unsigned int _comedi_buf_read_n_available(struct comedi_subdevice *s); +unsigned int _comedi_buf_read_alloc(struct comedi_subdevice *s, + unsigned int nbytes); +unsigned int _comedi_buf_read_free(struct comedi_subdevice *s, + unsigned int nbytes); +void _comedi_inc_scan_progress(struct comedi_subdevice *s, + unsigned int num_bytes); +void _comedi_event(struct comedi_device *dev, struct comedi_subdevice *s); +void comedi_device_cancel_all(struct comedi_device *dev); +bool comedi_can_auto_free_spriv(struct comedi_subdevice *s); + +extern unsigned int comedi_default_buf_size_kb; +extern unsigned int comedi_default_buf_maxsize_kb; + +/* drivers.c */ + +extern struct comedi_driver *comedi_drivers; +extern struct mutex comedi_drivers_list_lock; + +int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, + struct comedi_insn *insn, unsigned int *data); + +void comedi_device_detach_locked(struct comedi_device *dev); +void comedi_device_detach(struct comedi_device *dev); +int comedi_device_attach(struct comedi_device *dev, + struct comedi_devconfig *it); + +#ifdef CONFIG_PROC_FS + +/* proc.c */ + +void comedi_proc_init(void); +void comedi_proc_cleanup(void); +#else +static inline void comedi_proc_init(void) +{ +} + +static inline void comedi_proc_cleanup(void) +{ +} +#endif + +#endif /* _COMEDI_INTERNAL_H */ -- cgit v1.3.1