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, 53 insertions, 0 deletions

diff --git a/drivers/rapidio/rio.h b/drivers/rapidio/rio.h
new file mode 100644
index 000000000..a0e2a09dd
--- /dev/null
+++ b/drivers/rapidio/rio.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * RapidIO interconnect services
+ *
+ * Copyright 2005 MontaVista Software, Inc.
+ * Matt Porter <mporter@kernel.crashing.org>
+ */
+
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/rio.h>
+
+#define RIO_MAX_CHK_RETRY	3
+#define RIO_MPORT_ANY		(-1)
+
+/* Functions internal to the RIO core code */
+
+extern u32 rio_mport_get_feature(struct rio_mport *mport, int local, u16 destid,
+				 u8 hopcount, int ftr);
+extern u32 rio_mport_get_physefb(struct rio_mport *port, int local,
+				 u16 destid, u8 hopcount, u32 *rmap);
+extern u32 rio_mport_get_efb(struct rio_mport *port, int local, u16 destid,
+			     u8 hopcount, u32 from);
+extern int rio_mport_chk_dev_access(struct rio_mport *mport, u16 destid,
+				    u8 hopcount);
+extern int rio_lock_device(struct rio_mport *port, u16 destid,
+			u8 hopcount, int wait_ms);
+extern int rio_unlock_device(struct rio_mport *port, u16 destid, u8 hopcount);
+extern int rio_route_add_entry(struct rio_dev *rdev,
+			u16 table, u16 route_destid, u8 route_port, int lock);
+extern int rio_route_get_entry(struct rio_dev *rdev, u16 table,
+			u16 route_destid, u8 *route_port, int lock);
+extern int rio_route_clr_table(struct rio_dev *rdev, u16 table, int lock);
+extern int rio_set_port_lockout(struct rio_dev *rdev, u32 pnum, int lock);
+extern struct rio_dev *rio_get_comptag(u32 comp_tag, struct rio_dev *from);
+extern struct rio_net *rio_alloc_net(struct rio_mport *mport);
+extern int rio_add_net(struct rio_net *net);
+extern void rio_free_net(struct rio_net *net);
+extern int rio_add_device(struct rio_dev *rdev);
+extern void rio_del_device(struct rio_dev *rdev, enum rio_device_state state);
+extern int rio_enable_rx_tx_port(struct rio_mport *port, int local, u16 destid,
+				 u8 hopcount, u8 port_num);
+extern int rio_register_scan(int mport_id, struct rio_scan *scan_ops);
+extern void rio_attach_device(struct rio_dev *rdev);
+extern int rio_mport_scan(int mport_id);
+
+/* Structures internal to the RIO core code */
+extern const struct attribute_group *rio_dev_groups[];
+extern const struct attribute_group *rio_bus_groups[];
+extern const struct attribute_group *rio_mport_groups[];
+
+#define RIO_GET_DID(size, x)	(size ? (x & 0xffff) : ((x & 0x00ff0000) >> 16))
+#define RIO_SET_DID(size, x)	(size ? (x & 0xffff) : ((x & 0x000000ff) << 16))