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, 36 insertions, 0 deletions

diff --git a/fs/ntfs/collate.h b/fs/ntfs/collate.h
new file mode 100644
index 000000000..8ad1f04be
--- /dev/null
+++ b/fs/ntfs/collate.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Defines for NTFS kernel collation handling.
+ *
+ * Copyright (c) 2004 Anton Altaparmakov
+ *
+ * Part of this file is based on code from the NTFS-3G.
+ * and is copyrighted by the respective authors below:
+ * Copyright (c) 2004 Anton Altaparmakov
+ * Copyright (c) 2005 Yura Pakhuchiy
+ */
+
+#ifndef _LINUX_NTFS_COLLATE_H
+#define _LINUX_NTFS_COLLATE_H
+
+#include "volume.h"
+
+static inline bool ntfs_is_collation_rule_supported(__le32 cr)
+{
+	int i;
+
+	if (unlikely(cr != COLLATION_BINARY && cr != COLLATION_NTOFS_ULONG &&
+		     cr != COLLATION_FILE_NAME) && cr != COLLATION_NTOFS_ULONGS)
+		return false;
+	i = le32_to_cpu(cr);
+	if (likely(((i >= 0) && (i <= 0x02)) ||
+			((i >= 0x10) && (i <= 0x13))))
+		return true;
+	return false;
+}
+
+int ntfs_collate(struct ntfs_volume *vol, __le32 cr,
+		const void *data1, const u32 data1_len,
+		const void *data2, const u32 data2_len);
+
+#endif /* _LINUX_NTFS_COLLATE_H */