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, 44 insertions, 0 deletions

diff --git a/net/sunrpc/netns.h b/net/sunrpc/netns.h
new file mode 100644
index 000000000..4efb5f28d
--- /dev/null
+++ b/net/sunrpc/netns.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __SUNRPC_NETNS_H__
+#define __SUNRPC_NETNS_H__
+
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+
+struct cache_detail;
+
+struct sunrpc_net {
+	struct proc_dir_entry *proc_net_rpc;
+	struct cache_detail *ip_map_cache;
+	struct cache_detail *unix_gid_cache;
+	struct cache_detail *rsc_cache;
+	struct cache_detail *rsi_cache;
+
+	struct super_block *pipefs_sb;
+	struct rpc_pipe *gssd_dummy;
+	struct mutex pipefs_sb_lock;
+
+	struct list_head all_clients;
+	spinlock_t rpc_client_lock;
+
+	struct rpc_clnt *rpcb_local_clnt;
+	struct rpc_clnt *rpcb_local_clnt4;
+	spinlock_t rpcb_clnt_lock;
+	unsigned int rpcb_users;
+	unsigned int rpcb_is_af_local : 1;
+
+	struct mutex gssp_lock;
+	struct rpc_clnt *gssp_clnt;
+	int use_gss_proxy;
+	int pipe_version;
+	atomic_t pipe_users;
+	struct proc_dir_entry *use_gssp_proc;
+	struct proc_dir_entry *gss_krb5_enctypes;
+};
+
+extern unsigned int sunrpc_net_id;
+
+int ip_map_cache_create(struct net *);
+void ip_map_cache_destroy(struct net *);
+
+#endif