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, 49 insertions, 0 deletions

diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
new file mode 100644
index 000000000..d4c434956
--- /dev/null
+++ b/net/netlabel/netlabel_user.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * NetLabel NETLINK Interface
+ *
+ * This file defines the NETLINK interface for the NetLabel system.  The
+ * NetLabel system manages static and dynamic label mappings for network
+ * protocols such as CIPSO and RIPSO.
+ *
+ * Author: Paul Moore <paul@paul-moore.com>
+ */
+
+/*
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
+ */
+
+#ifndef _NETLABEL_USER_H
+#define _NETLABEL_USER_H
+
+#include <linux/types.h>
+#include <linux/skbuff.h>
+#include <linux/capability.h>
+#include <linux/audit.h>
+#include <net/netlink.h>
+#include <net/genetlink.h>
+#include <net/netlabel.h>
+
+/* NetLabel NETLINK helper functions */
+
+/**
+ * netlbl_netlink_auditinfo - Fetch the audit information from a NETLINK msg
+ * @audit_info: NetLabel audit information
+ */
+static inline void netlbl_netlink_auditinfo(struct netlbl_audit *audit_info)
+{
+	security_current_getlsmprop_subj(&audit_info->prop);
+	audit_info->loginuid = audit_get_loginuid(current);
+	audit_info->sessionid = audit_get_sessionid(current);
+}
+
+/* NetLabel NETLINK I/O functions */
+
+int netlbl_netlink_init(void);
+
+/* NetLabel Audit Functions */
+
+struct audit_buffer *netlbl_audit_start_common(int type,
+					      struct netlbl_audit *audit_info);
+
+#endif