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, 50 insertions, 0 deletions

diff --git a/fs/nfsd/flexfilelayoutxdr.h b/fs/nfsd/flexfilelayoutxdr.h
new file mode 100644
index 000000000..6d5a1066a
--- /dev/null
+++ b/fs/nfsd/flexfilelayoutxdr.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2016 Tom Haynes <loghyr@primarydata.com>
+ */
+#ifndef _NFSD_FLEXFILELAYOUTXDR_H
+#define _NFSD_FLEXFILELAYOUTXDR_H 1
+
+#include <linux/inet.h>
+#include "xdr4.h"
+
+#define FF_FLAGS_NO_LAYOUTCOMMIT 1
+#define FF_FLAGS_NO_IO_THRU_MDS  2
+#define FF_FLAGS_NO_READ_IO      4
+
+struct xdr_stream;
+
+#define FF_NETID_LEN		(4)
+#define FF_ADDR_LEN		(INET6_ADDRSTRLEN + 8)
+struct pnfs_ff_netaddr {
+	char				netid[FF_NETID_LEN + 1];
+	char				addr[FF_ADDR_LEN + 1];
+	u32				netid_len;
+	u32				addr_len;
+};
+
+struct pnfs_ff_device_addr {
+	struct pnfs_ff_netaddr		netaddr;
+	u32				version;
+	u32				minor_version;
+	u32				rsize;
+	u32				wsize;
+	bool				tightly_coupled;
+};
+
+struct pnfs_ff_layout {
+	u32				flags;
+	u32				stats_collect_hint;
+	kuid_t				uid;
+	kgid_t				gid;
+	struct nfsd4_deviceid		deviceid;
+	stateid_t			stateid;
+	struct nfs_fh			fh;
+};
+
+__be32 nfsd4_ff_encode_getdeviceinfo(struct xdr_stream *xdr,
+		const struct nfsd4_getdeviceinfo *gdp);
+__be32 nfsd4_ff_encode_layoutget(struct xdr_stream *xdr,
+		const struct nfsd4_layoutget *lgp);
+
+#endif /* _NFSD_FLEXFILELAYOUTXDR_H */