ftrace: Synchronize the initialization of ftrace_opsgrafted

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 <rostedt@goodmis.org>

1 files changed, 24 insertions, 0 deletions

diff --git a/fs/ntfs/reparse.h b/fs/ntfs/reparse.h
new file mode 100644
index 000000000..b6360b045
--- /dev/null
+++ b/fs/ntfs/reparse.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2008-2021 Jean-Pierre Andre
+ * Copyright (c) 2025 LG Electronics Co., Ltd.
+ */
+
+#ifndef _LINUX_NTFS_REPARSE_H
+#define _LINUX_NTFS_REPARSE_H
+
+extern __le16 reparse_index_name[];
+
+int ntfs_parse_reparse(struct ntfs_inode *ni, unsigned int *mode);
+unsigned int ntfs_reparse_tag_dt_types(struct ntfs_volume *vol, unsigned long mref);
+int ntfs_translate_symlink_path(struct dentry *dentry, const char *target,
+				char **translated);
+int ntfs_reparse_set_wsl_symlink(struct ntfs_inode *ni,
+				 const char *target, int target_len);
+int ntfs_reparse_set_native_symlink(struct ntfs_inode *ni,
+				    const char *symname, int symlen);
+int ntfs_reparse_set_wsl_not_symlink(struct ntfs_inode *ni, mode_t mode);
+int ntfs_delete_reparse_index(struct ntfs_inode *ni);
+int ntfs_remove_ntfs_reparse_data(struct ntfs_inode *ni);
+
+#endif /* _LINUX_NTFS_REPARSE_H */