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/include/net/handshake.h b/include/net/handshake.h
new file mode 100644
index 000000000..8ebd4f9ed
--- /dev/null
+++ b/include/net/handshake.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Generic netlink HANDSHAKE service.
+ *
+ * Author: Chuck Lever <chuck.lever@oracle.com>
+ *
+ * Copyright (c) 2023, Oracle and/or its affiliates.
+ */
+
+#ifndef _NET_HANDSHAKE_H
+#define _NET_HANDSHAKE_H
+
+enum {
+	TLS_NO_KEYRING = 0,
+	TLS_NO_PEERID = 0,
+	TLS_NO_CERT = 0,
+	TLS_NO_PRIVKEY = 0,
+};
+
+typedef void	(*tls_done_func_t)(void *data, int status,
+				   key_serial_t peerid);
+
+struct tls_handshake_args {
+	struct socket		*ta_sock;
+	tls_done_func_t		ta_done;
+	void			*ta_data;
+	const char		*ta_peername;
+	unsigned int		ta_timeout_ms;
+	key_serial_t		ta_keyring;
+	key_serial_t		ta_my_cert;
+	key_serial_t		ta_my_privkey;
+	unsigned int		ta_num_peerids;
+	key_serial_t		ta_my_peerids[5];
+};
+
+int tls_client_hello_anon(const struct tls_handshake_args *args, gfp_t flags);
+int tls_client_hello_x509(const struct tls_handshake_args *args, gfp_t flags);
+int tls_client_hello_psk(const struct tls_handshake_args *args, gfp_t flags);
+int tls_server_hello_x509(const struct tls_handshake_args *args, gfp_t flags);
+int tls_server_hello_psk(const struct tls_handshake_args *args, gfp_t flags);
+
+bool tls_handshake_cancel(struct sock *sk);
+void tls_handshake_close(struct socket *sock);
+
+u8 tls_get_record_type(const struct sock *sk, const struct cmsghdr *msg);
+void tls_alert_recv(const struct sock *sk, const struct msghdr *msg,
+		    u8 *level, u8 *description);
+
+#endif /* _NET_HANDSHAKE_H */