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, 174 insertions, 0 deletions

diff --git a/tools/firewire/nosy-dump.h b/tools/firewire/nosy-dump.h
new file mode 100644
index 000000000..69e5e594f
--- /dev/null
+++ b/tools/firewire/nosy-dump.h
@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __nosy_dump_h__
+#define __nosy_dump_h__
+
+#define array_length(array) (sizeof(array) / sizeof(array[0]))
+
+#define ACK_NO_ACK   0x0
+#define ACK_DONE(a)  ((a >> 2) == 0)
+#define ACK_BUSY(a)  ((a >> 2) == 1)
+#define ACK_ERROR(a) ((a >> 2) == 3)
+
+#include <stdint.h>
+
+struct phy_packet {
+	uint32_t timestamp;
+	union {
+		struct {
+			uint32_t zero:24;
+			uint32_t phy_id:6;
+			uint32_t identifier:2;
+		} common, link_on;
+
+		struct {
+			uint32_t zero:16;
+			uint32_t gap_count:6;
+			uint32_t set_gap_count:1;
+			uint32_t set_root:1;
+			uint32_t root_id:6;
+			uint32_t identifier:2;
+		} phy_config;
+
+		struct {
+			uint32_t more_packets:1;
+			uint32_t initiated_reset:1;
+			uint32_t port2:2;
+			uint32_t port1:2;
+			uint32_t port0:2;
+			uint32_t power_class:3;
+			uint32_t contender:1;
+			uint32_t phy_delay:2;
+			uint32_t phy_speed:2;
+			uint32_t gap_count:6;
+			uint32_t link_active:1;
+			uint32_t extended:1;
+			uint32_t phy_id:6;
+			uint32_t identifier:2;
+		} self_id;
+
+		struct {
+			uint32_t more_packets:1;
+			uint32_t reserved1:1;
+			uint32_t porth:2;
+			uint32_t portg:2;
+			uint32_t portf:2;
+			uint32_t porte:2;
+			uint32_t portd:2;
+			uint32_t portc:2;
+			uint32_t portb:2;
+			uint32_t porta:2;
+			uint32_t reserved0:2;
+			uint32_t sequence:3;
+			uint32_t extended:1;
+			uint32_t phy_id:6;
+			uint32_t identifier:2;
+		} ext_self_id;
+	};
+	uint32_t inverted;
+	uint32_t ack;
+};
+
+#define TCODE_PHY_PACKET 0x10
+
+#define PHY_PACKET_CONFIGURATION 0x00
+#define PHY_PACKET_LINK_ON 0x01
+#define PHY_PACKET_SELF_ID 0x02
+
+struct link_packet {
+	uint32_t timestamp;
+	union {
+		struct {
+			uint32_t priority:4;
+			uint32_t tcode:4;
+			uint32_t rt:2;
+			uint32_t tlabel:6;
+			uint32_t destination:16;
+
+			uint32_t offset_high:16;
+			uint32_t source:16;
+
+			uint32_t offset_low;
+		} common;
+
+		struct {
+			uint32_t common[3];
+			uint32_t crc;
+		} read_quadlet;
+
+		struct {
+			uint32_t common[3];
+			uint32_t data;
+			uint32_t crc;
+		} read_quadlet_response;
+
+		struct {
+			uint32_t common[3];
+			uint32_t extended_tcode:16;
+			uint32_t data_length:16;
+			uint32_t crc;
+		} read_block;
+
+		struct {
+			uint32_t common[3];
+			uint32_t extended_tcode:16;
+			uint32_t data_length:16;
+			uint32_t crc;
+			uint32_t data[0];
+			/* crc and ack follows. */
+		} read_block_response;
+
+		struct {
+			uint32_t common[3];
+			uint32_t data;
+			uint32_t crc;
+		} write_quadlet;
+
+		struct {
+			uint32_t common[3];
+			uint32_t extended_tcode:16;
+			uint32_t data_length:16;
+			uint32_t crc;
+			uint32_t data[0];
+			/* crc and ack follows. */
+		} write_block;
+
+		struct {
+			uint32_t common[3];
+			uint32_t crc;
+		} write_response;
+
+		struct {
+			uint32_t common[3];
+			uint32_t data;
+			uint32_t crc;
+		} cycle_start;
+
+		struct {
+			uint32_t sy:4;
+			uint32_t tcode:4;
+			uint32_t channel:6;
+			uint32_t tag:2;
+			uint32_t data_length:16;
+
+			uint32_t crc;
+		} iso_data;
+	};
+};
+
+struct subaction {
+	uint32_t ack;
+	size_t length;
+	struct list link;
+	struct link_packet packet;
+};
+
+struct link_transaction {
+	int request_node, response_node, tlabel;
+	struct subaction *request, *response;
+	struct list request_list, response_list;
+	struct list link;
+};
+
+int decode_fcp(struct link_transaction *t);
+
+#endif /* __nosy_dump_h__ */