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/notify/fsnotify.h | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 fs/notify/fsnotify.h (limited to 'fs/notify/fsnotify.h') diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h new file mode 100644 index 000000000..58c7bb25e --- /dev/null +++ b/fs/notify/fsnotify.h @@ -0,0 +1,114 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __FS_NOTIFY_FSNOTIFY_H_ +#define __FS_NOTIFY_FSNOTIFY_H_ + +#include +#include +#include +#include + +#include "../mount.h" + +/* + * fsnotify_connp_t is what we embed in objects which connector can be attached + * to. + */ +typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t; + +static inline struct inode *fsnotify_conn_inode( + struct fsnotify_mark_connector *conn) +{ + return conn->obj; +} + +static inline struct mount *fsnotify_conn_mount( + struct fsnotify_mark_connector *conn) +{ + return real_mount(conn->obj); +} + +static inline struct super_block *fsnotify_conn_sb( + struct fsnotify_mark_connector *conn) +{ + return conn->obj; +} + +static inline struct mnt_namespace *fsnotify_conn_mntns( + struct fsnotify_mark_connector *conn) +{ + return conn->obj; +} + +static inline struct super_block *fsnotify_object_sb(void *obj, + enum fsnotify_obj_type obj_type) +{ + switch (obj_type) { + case FSNOTIFY_OBJ_TYPE_INODE: + return ((struct inode *)obj)->i_sb; + case FSNOTIFY_OBJ_TYPE_VFSMOUNT: + return ((struct vfsmount *)obj)->mnt_sb; + case FSNOTIFY_OBJ_TYPE_SB: + return (struct super_block *)obj; + default: + return NULL; + } +} + +static inline struct super_block *fsnotify_connector_sb( + struct fsnotify_mark_connector *conn) +{ + return fsnotify_object_sb(conn->obj, conn->type); +} + +static inline fsnotify_connp_t *fsnotify_sb_marks(struct super_block *sb) +{ + struct fsnotify_sb_info *sbinfo = fsnotify_sb_info(sb); + + return sbinfo ? &sbinfo->sb_marks : NULL; +} + +/* destroy all events sitting in this groups notification queue */ +extern void fsnotify_flush_notify(struct fsnotify_group *group); + +/* protects reads of inode and vfsmount marks list */ +extern struct srcu_struct fsnotify_mark_srcu; + +/* compare two groups for sorting of marks lists */ +extern int fsnotify_compare_groups(struct fsnotify_group *a, + struct fsnotify_group *b); + +/* Destroy all inode marks for given superblock */ +void fsnotify_unmount_inodes(struct fsnotify_sb_info *sbinfo); + +/* Destroy all marks attached to an object via connector */ +extern void fsnotify_destroy_marks(fsnotify_connp_t *connp); +/* run the list of all marks associated with inode and destroy them */ +static inline void fsnotify_clear_marks_by_inode(struct inode *inode) +{ + fsnotify_destroy_marks(&inode->i_fsnotify_marks); +} +/* run the list of all marks associated with vfsmount and destroy them */ +static inline void fsnotify_clear_marks_by_mount(struct vfsmount *mnt) +{ + fsnotify_destroy_marks(&real_mount(mnt)->mnt_fsnotify_marks); +} +/* run the list of all marks associated with sb and destroy them */ +static inline void fsnotify_clear_marks_by_sb(struct super_block *sb) +{ + fsnotify_destroy_marks(fsnotify_sb_marks(sb)); +} + +static inline void fsnotify_clear_marks_by_mntns(struct mnt_namespace *mntns) +{ + fsnotify_destroy_marks(&mntns->n_fsnotify_marks); +} + +/* + * update the dentry->d_flags of all of inode's children to indicate if inode cares + * about events that happen to its children. + */ +extern void fsnotify_set_children_dentry_flags(struct inode *inode); + +void fsnotify_init_connector_caches(void); + +#endif /* __FS_NOTIFY_FSNOTIFY_H_ */ -- cgit v1.3.1