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 --- block/blk-mq-debugfs.h | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 block/blk-mq-debugfs.h (limited to 'block/blk-mq-debugfs.h') diff --git a/block/blk-mq-debugfs.h b/block/blk-mq-debugfs.h new file mode 100644 index 000000000..49bb1aaa8 --- /dev/null +++ b/block/blk-mq-debugfs.h @@ -0,0 +1,91 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef INT_BLK_MQ_DEBUGFS_H +#define INT_BLK_MQ_DEBUGFS_H + +#ifdef CONFIG_BLK_DEBUG_FS + +#include + +struct blk_mq_hw_ctx; + +struct blk_mq_debugfs_attr { + const char *name; + umode_t mode; + int (*show)(void *, struct seq_file *); + ssize_t (*write)(void *, const char __user *, size_t, loff_t *); + /* Set either .show or .seq_ops. */ + const struct seq_operations *seq_ops; +}; + +int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq); +int blk_mq_debugfs_rq_show(struct seq_file *m, void *v); + +void blk_mq_debugfs_register(struct request_queue *q); +void blk_mq_debugfs_register_hctx(struct request_queue *q, + struct blk_mq_hw_ctx *hctx); +void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx); +void blk_mq_debugfs_register_hctxs(struct request_queue *q); +void blk_mq_debugfs_unregister_hctxs(struct request_queue *q); + +void blk_mq_debugfs_register_sched(struct request_queue *q); +void blk_mq_debugfs_unregister_sched(struct request_queue *q); +void blk_mq_debugfs_register_sched_hctx(struct request_queue *q, + struct blk_mq_hw_ctx *hctx); +void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx); + +void blk_mq_debugfs_register_rq_qos(struct request_queue *q); +#else +static inline void blk_mq_debugfs_register(struct request_queue *q) +{ +} + +static inline void blk_mq_debugfs_register_hctx(struct request_queue *q, + struct blk_mq_hw_ctx *hctx) +{ +} + +static inline void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx) +{ +} + +static inline void blk_mq_debugfs_register_hctxs(struct request_queue *q) +{ +} + +static inline void blk_mq_debugfs_unregister_hctxs(struct request_queue *q) +{ +} + +static inline void blk_mq_debugfs_register_sched(struct request_queue *q) +{ +} + +static inline void blk_mq_debugfs_unregister_sched(struct request_queue *q) +{ +} + +static inline void blk_mq_debugfs_register_sched_hctx(struct request_queue *q, + struct blk_mq_hw_ctx *hctx) +{ +} + +static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx) +{ +} + +static inline void blk_mq_debugfs_register_rq_qos(struct request_queue *q) +{ +} + +#endif + +#if defined(CONFIG_BLK_DEV_ZONED) && defined(CONFIG_BLK_DEBUG_FS) +int queue_zone_wplugs_show(void *data, struct seq_file *m); +#else +static inline int queue_zone_wplugs_show(void *data, struct seq_file *m) +{ + return 0; +} +#endif + +#endif -- cgit v1.3.1