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 --- fs/btrfs/ref-verify.h | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 fs/btrfs/ref-verify.h (limited to 'fs/btrfs/ref-verify.h') diff --git a/fs/btrfs/ref-verify.h b/fs/btrfs/ref-verify.h new file mode 100644 index 000000000..1ce544d53 --- /dev/null +++ b/fs/btrfs/ref-verify.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2014 Facebook. All rights reserved. + */ + +#ifndef BTRFS_REF_VERIFY_H +#define BTRFS_REF_VERIFY_H + +#include +#include + +struct btrfs_fs_info; +struct btrfs_ref; + +#ifdef CONFIG_BTRFS_DEBUG + +#include + +int btrfs_build_ref_tree(struct btrfs_fs_info *fs_info); +void btrfs_free_ref_cache(struct btrfs_fs_info *fs_info); +int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info, + const struct btrfs_ref *generic_ref); +void btrfs_free_ref_tree_range(struct btrfs_fs_info *fs_info, u64 start, + u64 len); + +static inline void btrfs_init_ref_verify(struct btrfs_fs_info *fs_info) +{ + spin_lock_init(&fs_info->ref_verify_lock); + fs_info->block_tree = RB_ROOT; +} +#else +static inline int btrfs_build_ref_tree(struct btrfs_fs_info *fs_info) +{ + return 0; +} + +static inline void btrfs_free_ref_cache(struct btrfs_fs_info *fs_info) +{ +} + +static inline int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info, + const struct btrfs_ref *generic_ref) +{ + return 0; +} + +static inline void btrfs_free_ref_tree_range(struct btrfs_fs_info *fs_info, + u64 start, u64 len) +{ +} + +static inline void btrfs_init_ref_verify(struct btrfs_fs_info *fs_info) +{ +} + +#endif /* CONFIG_BTRFS_DEBUG */ + +#endif -- cgit v1.3.1