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/pnode.h | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 fs/pnode.h (limited to 'fs/pnode.h') diff --git a/fs/pnode.h b/fs/pnode.h new file mode 100644 index 000000000..b029db225 --- /dev/null +++ b/fs/pnode.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/fs/pnode.h + * + * (C) Copyright IBM Corporation 2005. + */ +#ifndef _LINUX_PNODE_H +#define _LINUX_PNODE_H + +#include +#include "mount.h" + +#define IS_MNT_SHARED(m) ((m)->mnt_t_flags & T_SHARED) +#define IS_MNT_SLAVE(m) ((m)->mnt_master) +#define IS_MNT_NEW(m) (!(m)->mnt_ns) +#define CLEAR_MNT_SHARED(m) ((m)->mnt_t_flags &= ~T_SHARED) +#define IS_MNT_UNBINDABLE(m) ((m)->mnt_t_flags & T_UNBINDABLE) +#define IS_MNT_MARKED(m) ((m)->mnt_t_flags & T_MARKED) +#define SET_MNT_MARK(m) ((m)->mnt_t_flags |= T_MARKED) +#define CLEAR_MNT_MARK(m) ((m)->mnt_t_flags &= ~T_MARKED) +#define IS_MNT_LOCKED(m) ((m)->mnt.mnt_flags & MNT_LOCKED) + +#define CL_EXPIRE 0x01 +#define CL_SLAVE 0x02 +#define CL_COPY_UNBINDABLE 0x04 +#define CL_MAKE_SHARED 0x08 +#define CL_PRIVATE 0x10 +#define CL_COPY_MNT_NS_FILE 0x40 + +/* + * EXCL[namespace_sem] + */ +static inline void set_mnt_shared(struct mount *mnt) +{ + mnt->mnt_t_flags &= ~T_SHARED_MASK; + mnt->mnt_t_flags |= T_SHARED; +} + +static inline bool peers(const struct mount *m1, const struct mount *m2) +{ + return m1->mnt_group_id == m2->mnt_group_id && m1->mnt_group_id; +} + +void change_mnt_propagation(struct mount *, int); +void bulk_make_private(struct list_head *); +int propagate_mnt(struct mount *, struct mountpoint *, struct mount *, + struct hlist_head *); +void propagate_umount(struct list_head *); +int propagate_mount_busy(struct mount *, int); +void propagate_mount_unlock(struct mount *); +void mnt_release_group_id(struct mount *); +int get_dominating_id(struct mount *mnt, const struct path *root); +int mnt_get_count(struct mount *mnt); +void mnt_set_mountpoint(struct mount *, struct mountpoint *, + struct mount *); +void mnt_change_mountpoint(struct mount *parent, struct mountpoint *mp, + struct mount *mnt); +struct mount *copy_tree(struct mount *, struct dentry *, int); +bool is_path_reachable(struct mount *, struct dentry *, + const struct path *root); +int count_mounts(struct mnt_namespace *ns, struct mount *mnt); +bool propagation_would_overmount(const struct mount *from, + const struct mount *to, + const struct mountpoint *mp); +#endif /* _LINUX_PNODE_H */ -- cgit v1.3.1