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 --- include/sound/seq_device.h | 86 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 include/sound/seq_device.h (limited to 'include/sound/seq_device.h') diff --git a/include/sound/seq_device.h b/include/sound/seq_device.h new file mode 100644 index 000000000..3137d4c5f --- /dev/null +++ b/include/sound/seq_device.h @@ -0,0 +1,86 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef __SOUND_SEQ_DEVICE_H +#define __SOUND_SEQ_DEVICE_H + +/* + * ALSA sequencer device management + * Copyright (c) 1999 by Takashi Iwai + */ + +/* + * registered device information + */ + +struct snd_seq_device { + /* device info */ + struct snd_card *card; /* sound card */ + int device; /* device number */ + const char *id; /* driver id */ + char name[80]; /* device name */ + int argsize; /* size of the argument */ + void *driver_data; /* private data for driver */ + void *private_data; /* private data for the caller */ + void (*private_free)(struct snd_seq_device *device); + struct device dev; + unsigned char args[]; /* driver-specific argument */ +}; + +#define to_seq_dev(_dev) \ + container_of(_dev, struct snd_seq_device, dev) + +/* sequencer driver */ + +/* driver operators + * probe: + * Initialize the device with given parameters. + * Typically, + * 1. call snd_hwdep_new + * 2. allocate private data and initialize it + * 3. call snd_hwdep_register + * 4. store the instance to dev->driver_data pointer. + * + * remove: + * Release the private data. + * Typically, call snd_device_free(dev->card, dev->driver_data) + */ +struct snd_seq_driver { + int (*probe)(struct snd_seq_device *dev); + void (*remove)(struct snd_seq_device *dev); + struct device_driver driver; + char *id; + int argsize; +}; + +#define to_seq_drv(_drv) \ + container_of(_drv, struct snd_seq_driver, driver) + +/* + * prototypes + */ +#ifdef CONFIG_MODULES +void snd_seq_device_load_drivers(void); +#else +#define snd_seq_device_load_drivers() +#endif +int snd_seq_device_new(struct snd_card *card, int device, const char *id, + int argsize, struct snd_seq_device **result); + +#define SNDRV_SEQ_DEVICE_ARGPTR(dev) ((void *)(dev)->args) + +int __must_check __snd_seq_driver_register(struct snd_seq_driver *drv, + struct module *mod); +#define snd_seq_driver_register(drv) \ + __snd_seq_driver_register(drv, THIS_MODULE) +void snd_seq_driver_unregister(struct snd_seq_driver *drv); + +#define module_snd_seq_driver(drv) \ + module_driver(drv, snd_seq_driver_register, snd_seq_driver_unregister) + +/* + * id strings for generic devices + */ +#define SNDRV_SEQ_DEV_ID_MIDISYNTH "seq-midi" +#define SNDRV_SEQ_DEV_ID_OPL3 "opl3-synth" +#define SNDRV_SEQ_DEV_ID_UMP "seq-ump-client" + +#endif /* __SOUND_SEQ_DEVICE_H */ -- cgit v1.3.1