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, 28 insertions, 0 deletions

diff --git a/include/net/rawv6.h b/include/net/rawv6.h
new file mode 100644
index 000000000..82810cbe3
--- /dev/null
+++ b/include/net/rawv6.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NET_RAWV6_H
+#define _NET_RAWV6_H
+
+#include <net/protocol.h>
+#include <net/raw.h>
+
+extern struct raw_hashinfo raw_v6_hashinfo;
+bool raw_v6_match(struct net *net, const struct sock *sk, unsigned short num,
+		  const struct in6_addr *loc_addr,
+		  const struct in6_addr *rmt_addr, int dif, int sdif);
+
+int raw_abort(struct sock *sk, int err);
+
+void raw6_icmp_error(struct sk_buff *, int nexthdr,
+		u8 type, u8 code, int inner_offset, __be32);
+bool raw6_local_deliver(struct sk_buff *, int);
+
+int rawv6_rcv(struct sock *sk, struct sk_buff *skb);
+
+#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
+int rawv6_mh_filter_register(int (*filter)(struct sock *sock,
+					   struct sk_buff *skb));
+int rawv6_mh_filter_unregister(int (*filter)(struct sock *sock,
+					     struct sk_buff *skb));
+#endif
+
+#endif