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, 182 insertions, 0 deletions

diff --git a/tools/lib/thermal/include/thermal.h b/tools/lib/thermal/include/thermal.h
new file mode 100644
index 000000000..d9097271d
--- /dev/null
+++ b/tools/lib/thermal/include/thermal.h
@@ -0,0 +1,182 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+/* Copyright (C) 2022, Linaro Ltd - Daniel Lezcano <daniel.lezcano@linaro.org> */
+#ifndef __LIBTHERMAL_H
+#define __LIBTHERMAL_H
+
+#include <linux/thermal.h>
+#include <sys/types.h>
+
+#ifndef LIBTHERMAL_API
+#define LIBTHERMAL_API __attribute__((visibility("default")))
+#endif
+
+#ifndef THERMAL_THRESHOLD_WAY_UP
+#define THERMAL_THRESHOLD_WAY_UP 0x1
+#endif
+
+#ifndef THERMAL_THRESHOLD_WAY_DOWN
+#define THERMAL_THRESHOLD_WAY_DOWN 0x2
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct thermal_sampling_ops {
+	int (*tz_temp)(int tz_id, int temp, void *arg);
+};
+
+struct thermal_events_ops {
+	int (*tz_create)(const char *name, int tz_id, void *arg);
+	int (*tz_delete)(int tz_id, void *arg);
+	int (*tz_enable)(int tz_id, void *arg);
+	int (*tz_disable)(int tz_id, void *arg);
+	int (*trip_high)(int tz_id, int trip_id, int temp, void *arg);
+	int (*trip_low)(int tz_id, int trip_id, int temp, void *arg);
+	int (*trip_add)(int tz_id, int trip_id, int type, int temp, int hyst, void *arg);
+	int (*trip_change)(int tz_id, int trip_id, int type, int temp, int hyst, void *arg);
+	int (*trip_delete)(int tz_id, int trip_id, void *arg);
+	int (*cdev_add)(const char *name, int cdev_id, int max_state, void *arg);
+	int (*cdev_delete)(int cdev_id, void *arg);
+	int (*cdev_update)(int cdev_id, int cur_state, void *arg);
+	int (*gov_change)(int tz_id, const char *gov_name, void *arg);
+	int (*threshold_add)(int tz_id, int temperature, int direction, void *arg);
+	int (*threshold_delete)(int tz_id, int temperature, int direction, void *arg);
+	int (*threshold_flush)(int tz_id, void *arg);
+	int (*threshold_up)(int tz_id, int temp, int prev_temp, void *arg);
+	int (*threshold_down)(int tz_id, int temp, int prev_temp, void *arg);
+};
+
+struct thermal_ops {
+	struct thermal_sampling_ops sampling;
+	struct thermal_events_ops events;
+};
+
+struct thermal_trip {
+	int id;
+	int type;
+	int temp;
+	int hyst;
+};
+
+struct thermal_threshold {
+	int temperature;
+	int direction;
+};
+
+struct thermal_zone {
+	int id;
+	int temp;
+	char name[THERMAL_NAME_LENGTH];
+	char governor[THERMAL_NAME_LENGTH];
+	struct thermal_trip *trip;
+	struct thermal_threshold *thresholds;
+};
+
+struct thermal_cdev {
+	int id;
+	char name[THERMAL_NAME_LENGTH];
+	int max_state;
+	int min_state;
+	int cur_state;
+};
+
+typedef enum {
+	THERMAL_ERROR = -1,
+	THERMAL_SUCCESS = 0,
+} thermal_error_t;
+
+struct thermal_handler;
+
+typedef int (*cb_tz_t)(struct thermal_zone *, void *);
+
+typedef int (*cb_tt_t)(struct thermal_trip *, void *);
+
+typedef int (*cb_tc_t)(struct thermal_cdev *, void *);
+
+typedef int (*cb_th_t)(struct thermal_threshold *, void *);
+
+LIBTHERMAL_API int for_each_thermal_zone(struct thermal_zone *tz, cb_tz_t cb, void *arg);
+
+LIBTHERMAL_API int for_each_thermal_trip(struct thermal_trip *tt, cb_tt_t cb, void *arg);
+
+LIBTHERMAL_API int for_each_thermal_cdev(struct thermal_cdev *cdev, cb_tc_t cb, void *arg);
+
+LIBTHERMAL_API int for_each_thermal_threshold(struct thermal_threshold *th, cb_th_t cb, void *arg);
+
+LIBTHERMAL_API struct thermal_zone *thermal_zone_find_by_name(struct thermal_zone *tz,
+							      const char *name);
+
+LIBTHERMAL_API struct thermal_zone *thermal_zone_find_by_id(struct thermal_zone *tz, int id);
+
+LIBTHERMAL_API struct thermal_zone *thermal_zone_discover(struct thermal_handler *th);
+
+LIBTHERMAL_API struct thermal_handler *thermal_init(struct thermal_ops *ops);
+
+LIBTHERMAL_API void thermal_exit(struct thermal_handler *th);
+
+/*
+ * Netlink thermal events
+ */
+LIBTHERMAL_API thermal_error_t thermal_events_exit(struct thermal_handler *th);
+
+LIBTHERMAL_API thermal_error_t thermal_events_init(struct thermal_handler *th);
+
+LIBTHERMAL_API thermal_error_t thermal_events_handle(struct thermal_handler *th, void *arg);
+
+LIBTHERMAL_API int thermal_events_fd(struct thermal_handler *th);
+
+/*
+ * Netlink thermal commands
+ */
+LIBTHERMAL_API thermal_error_t thermal_cmd_exit(struct thermal_handler *th);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_init(struct thermal_handler *th);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_get_tz(struct thermal_handler *th,
+						  struct thermal_zone **tz);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_get_cdev(struct thermal_handler *th,
+						    struct thermal_cdev **tc);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_get_trip(struct thermal_handler *th,
+						    struct thermal_zone *tz);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_get_governor(struct thermal_handler *th,
+							struct thermal_zone *tz);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_get_temp(struct thermal_handler *th,
+						    struct thermal_zone *tz);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_threshold_get(struct thermal_handler *th,
+							 struct thermal_zone *tz);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_threshold_add(struct thermal_handler *th,
+                                                         struct thermal_zone *tz,
+                                                         int temperature,
+                                                         int direction);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_threshold_delete(struct thermal_handler *th,
+                                                            struct thermal_zone *tz,
+                                                            int temperature,
+                                                            int direction);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_threshold_flush(struct thermal_handler *th,
+                                                           struct thermal_zone *tz);
+
+/*
+ * Netlink thermal samples
+ */
+LIBTHERMAL_API thermal_error_t thermal_sampling_exit(struct thermal_handler *th);
+
+LIBTHERMAL_API thermal_error_t thermal_sampling_init(struct thermal_handler *th);
+
+LIBTHERMAL_API thermal_error_t thermal_sampling_handle(struct thermal_handler *th, void *arg);
+
+LIBTHERMAL_API int thermal_sampling_fd(struct thermal_handler *th);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __LIBTHERMAL_H */