[lttng-ust.git] / include / ust / tracepoint.h

#ifndef _UST_TRACEPOINT_H
#define _UST_TRACEPOINT_H

/*
 * Copyright (C) 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
 * Copyright (C) 2009 Pierre-Marc Fournier
 * Copyright (C) 2009 Steven Rostedt <rostedt@goodmis.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 *
 * Heavily inspired from the Linux Kernel Markers.
 *
 * Ported to userspace by Pierre-Marc Fournier.
 */

#define _LGPL_SOURCE
#include <urcu-bp.h>
#include <ust/immediate.h>
#include <ust/core.h>

struct module;
struct tracepoint;

struct probe {
	void *func;
	void *data;
};

struct tracepoint {
	const char *name;		/* Tracepoint name */
	DEFINE_IMV(char, state);	/* State. */
	struct probe *probes;
};

#define PARAMS(args...) args

#define TP_PROTO(args...)	args
#define TP_ARGS(args...)	args

#define CONFIG_TRACEPOINTS
#ifdef CONFIG_TRACEPOINTS

/*
 * it_func[0] is never NULL because there is at least one element in the array
 * when the array itself is non NULL.
 */
#define __DO_TRACE(tp, proto, args)					\
	do {								\
		struct probe *it_probe_ptr;				\
		void *it_func;						\
		void *__data;						\
									\
		rcu_read_lock();					\
		it_probe_ptr = rcu_dereference((tp)->probes);		\
		if (it_probe_ptr) {					\
			do {						\
				it_func	= (it_probe_ptr)->func;		\
				__data = (it_probe_ptr)->data;		\
				((void(*)(proto))(it_func))(args);	\
			} while ((++it_probe_ptr)->func);		\
		}							\
		rcu_read_unlock();					\
	} while (0)

#define __CHECK_TRACE(name, generic, proto, args)			\
	do {								\
		if (!generic) {						\
			if (unlikely(imv_read(__tracepoint_##name.state))) \
				__DO_TRACE(&__tracepoint_##name,	\
					TP_PROTO(proto), TP_ARGS(args));	\
		} else {						\
			if (unlikely(_imv_read(__tracepoint_##name.state))) \
				__DO_TRACE(&__tracepoint_##name,	\
					TP_PROTO(proto), TP_ARGS(args));	\
		}							\
	} while (0)

/*
 * Make sure the alignment of the structure in the __tracepoints section will
 * not add unwanted padding between the beginning of the section and the
 * structure. Force alignment to the same alignment as the section start.
 *
 * The "generic" argument, passed to the declared __trace_##name inline
 * function controls which tracepoint enabling mechanism must be used.
 * If generic is true, a variable read is used.
 * If generic is false, immediate values are used.
 */
#define __DECLARE_TRACE(name, proto, args, data_proto, data_args)	\
	extern struct tracepoint __tracepoint_##name;			\
	static inline void trace_##name(proto)				\
	{								\
		__CHECK_TRACE(name, 0, TP_PROTO(data_proto),		\
			      TP_ARGS(data_args));			\
	}								\
	static inline void _trace_##name(proto)				\
	{								\
		__CHECK_TRACE(name, 1, TP_PROTO(data_proto),		\
			      TP_ARGS(data_args));			\
	}								\
	static inline int						\
	register_trace_##name(void (*probe)(data_proto), void *data)	\
	{								\
		return tracepoint_probe_register(#name, (void *)probe,	\
						 data);			\
									\
	}								\
	static inline int						\
	unregister_trace_##name(void (*probe)(data_proto), void *data)	\
	{								\
		return tracepoint_probe_unregister(#name, (void *)probe, \
						   data);		\
	}

#define DEFINE_TRACE_FN(name, reg, unreg)				\
	static const char __tpstrtab_##name[]				\
	__attribute__((section("__tracepoints_strings"))) = #name;	\
	struct tracepoint __tracepoint_##name				\
	__attribute__((section("__tracepoints"))) =			\
		{ __tpstrtab_##name, 0, NULL };				\
	static struct tracepoint * const __tracepoint_ptr_##name	\
	__attribute__((used, section("__tracepoints_ptrs"))) =		\
		&__tracepoint_##name;

#define DEFINE_TRACE(name)						\
	DEFINE_TRACE_FN(name, NULL, NULL)

extern void tracepoint_update_probe_range(struct tracepoint * const *begin,
	struct tracepoint * const *end);

#else /* !CONFIG_TRACEPOINTS */
#define __DECLARE_TRACE(name, proto, args)				\
	static inline void trace_##name(proto)				\
	{ }								\
	static inline void _trace_##name(proto)				\
	{ }								\
	static inline int register_trace_##name(void (*probe)(proto), void *data)	\
	{								\
		return -ENOSYS;						\
	}								\
	static inline int unregister_trace_##name(void (*probe)(proto), void *data)	\
	{								\
		return -ENOSYS;						\
	}

#define DEFINE_TRACE(name)
#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
#define EXPORT_TRACEPOINT_SYMBOL(name)

static inline void tracepoint_update_probe_range(struct tracepoint *begin,
	struct tracepoint *end)
{ }
#endif /* CONFIG_TRACEPOINTS */

#define DECLARE_TRACE(name, proto, args)			\
	__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),	\
			PARAMS(void *__data, proto),		\
			PARAMS(__data, args))

/*
 * Connect a probe to a tracepoint.
 * Internal API, should not be used directly.
 */
extern int tracepoint_probe_register(const char *name, void *probe, void *data);

/*
 * Disconnect a probe from a tracepoint.
 * Internal API, should not be used directly.
 */
extern int tracepoint_probe_unregister(const char *name, void *probe, void *data);

extern int tracepoint_probe_register_noupdate(const char *name, void *probe,
					      void *data);
extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe,
						void *data);
extern void tracepoint_probe_update_all(void);

struct tracepoint_iter {
//ust//	struct module *module;
	struct tracepoint_lib *lib;
	struct tracepoint * const *tracepoint;
};

extern void tracepoint_iter_start(struct tracepoint_iter *iter);
extern void tracepoint_iter_next(struct tracepoint_iter *iter);
extern void tracepoint_iter_stop(struct tracepoint_iter *iter);
extern void tracepoint_iter_reset(struct tracepoint_iter *iter);
extern int tracepoint_get_iter_range(struct tracepoint * const **tracepoint,
	struct tracepoint * const *begin, struct tracepoint * const *end);

/*
 * tracepoint_synchronize_unregister must be called between the last tracepoint
 * probe unregistration and the end of module exit to make sure there is no
 * caller executing a probe when it is freed.
 */
static inline void tracepoint_synchronize_unregister(void)
{
//ust//	synchronize_sched();
}

struct tracepoint_lib {
	struct tracepoint * const *tracepoints_start;
	int tracepoints_count;
	struct cds_list_head list;
};

extern int tracepoint_register_lib(struct tracepoint * const *tracepoints_start,
				   int tracepoints_count);
extern int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start);

#define TRACEPOINT_LIB							\
	extern struct tracepoint * const __start___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
	extern struct tracepoint * const __stop___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
	static void __attribute__((constructor)) __tracepoints__init(void)	\
	{									\
		tracepoint_register_lib(__start___tracepoints_ptrs,			\
					__stop___tracepoints_ptrs -			\
					__start___tracepoints_ptrs);			\
	}									\
										\
	static void __attribute__((destructor)) __tracepoints__destroy(void)	\
	{									\
		tracepoint_unregister_lib(__start___tracepoints_ptrs);		\
	}


#ifndef TRACE_EVENT
/*
 * For use with the TRACE_EVENT macro:
 *
 * We define a tracepoint, its arguments, its printf format
 * and its 'fast binary record' layout.
 *
 * Firstly, name your tracepoint via TRACE_EVENT(name : the
 * 'subsystem_event' notation is fine.
 *
 * Think about this whole construct as the
 * 'trace_sched_switch() function' from now on.
 *
 *
 *  TRACE_EVENT(sched_switch,
 *
 *	*
 *	* A function has a regular function arguments
 *	* prototype, declare it via TP_PROTO():
 *	*
 *
 *	TP_PROTO(struct rq *rq, struct task_struct *prev,
 *		 struct task_struct *next),
 *
 *	*
 *	* Define the call signature of the 'function'.
 *	* (Design sidenote: we use this instead of a
 *	*  TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
 *	*
 *
 *	TP_ARGS(rq, prev, next),
 *
 *	*
 *	* Fast binary tracing: define the trace record via
 *	* TP_STRUCT__entry(). You can think about it like a
 *	* regular C structure local variable definition.
 *	*
 *	* This is how the trace record is structured and will
 *	* be saved into the ring buffer. These are the fields
 *	* that will be exposed to readers.
 *	*
 *	* The declared 'local variable' is called '__entry'
 *	*
 *	* __field(pid_t, prev_prid) is equivalent to a standard declariton:
 *	*
 *	*	pid_t	prev_pid;
 *	*
 *	* __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
 *	*
 *	*	char	prev_comm[TASK_COMM_LEN];
 *	*
 *
 *	TP_STRUCT__entry(
 *		__array(	char,	prev_comm,	TASK_COMM_LEN	)
 *		__field(	pid_t,	prev_pid			)
 *		__field(	int,	prev_prio			)
 *		__array(	char,	next_comm,	TASK_COMM_LEN	)
 *		__field(	pid_t,	next_pid			)
 *		__field(	int,	next_prio			)
 *	),
 *
 *	*
 *	* Assign the entry into the trace record, by embedding
 *	* a full C statement block into TP_fast_assign(). You
 *	* can refer to the trace record as '__entry' -
 *	* otherwise you can put arbitrary C code in here.
 *	*
 *	* Note: this C code will execute every time a trace event
 *	* happens, on an active tracepoint.
 *	*
 *
 *	TP_fast_assign(
 *		memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
 *		__entry->prev_pid	= prev->pid;
 *		__entry->prev_prio	= prev->prio;
 *		memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
 *		__entry->next_pid	= next->pid;
 *		__entry->next_prio	= next->prio;
 *	)
 *
 *	*
 *	* Formatted output of a trace record via TP_printf().
 *	* This is how the tracepoint will appear under debugging
 *	* of tracepoints.
 *	*
 *	* (raw-binary tracing wont actually perform this step.)
 *	*
 *
 *	TP_printf("task %s:%d [%d] ==> %s:%d [%d]",
 *		__entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
 *		__entry->next_comm, __entry->next_pid, __entry->next_prio),
 *
 * );
 *
 * This macro construct is thus used for the regular printf format
 * tracing setup.
 *
 * A set of (un)registration functions can be passed to the variant
 * TRACE_EVENT_FN to perform any (un)registration work.
 */

struct trace_event {
	const char *name;
	int (*regfunc)(void *data);
	int (*unregfunc)(void *data);
};

struct trace_event_lib {
	struct trace_event * const *trace_events_start;
	int trace_events_count;
	struct cds_list_head list;
};

struct trace_event_iter {
	struct trace_event_lib *lib;
	struct trace_event * const *trace_event;
};

extern void lock_trace_events(void);
extern void unlock_trace_events(void);

extern void trace_event_iter_start(struct trace_event_iter *iter);
extern void trace_event_iter_next(struct trace_event_iter *iter);
extern void trace_event_iter_reset(struct trace_event_iter *iter);

extern int trace_event_get_iter_range(struct trace_event * const **trace_event,
				      struct trace_event * const *begin,
				      struct trace_event * const *end);

extern void trace_event_update_process(void);
extern int is_trace_event_enabled(const char *channel, const char *name);

extern int trace_event_register_lib(struct trace_event * const *start_trace_events,
				    int trace_event_count);

extern int trace_event_unregister_lib(struct trace_event * const *start_trace_events);

#define TRACE_EVENT_LIB							\
	extern struct trace_event * const __start___trace_events_ptrs[]	\
	__attribute__((weak, visibility("hidden")));			\
	extern struct trace_event * const __stop___trace_events_ptrs[]	\
	__attribute__((weak, visibility("hidden")));			\
	static void __attribute__((constructor))			\
	__trace_events__init(void)					\
	{								\
		trace_event_register_lib(__start___trace_events_ptrs,	\
					 __stop___trace_events_ptrs -	\
					 __start___trace_events_ptrs);	\
	}								\
									\
	static void __attribute__((destructor))				\
	__trace_event__destroy(void)					\
	{								\
		trace_event_unregister_lib(__start___trace_events_ptrs);\
	}

#define DECLARE_TRACE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
#define DEFINE_TRACE_EVENT(template, name, proto, args)		\
	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
#define DEFINE_TRACE_EVENT_PRINT(template, name, proto, args, print)	\
	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))

#define TRACE_EVENT(name, proto, args, struct, assign, print)	\
	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
#define TRACE_EVENT_FN(name, proto, args, struct,		\
		assign, print, reg, unreg)			\
	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))

#endif /* ifdef TRACE_EVENT (see note above) */


#endif /* _UST_TRACEPOINT_H */
Commit	Line	Data
27b052e3 PMF	1	#ifndef _UST_TRACEPOINT_H
27b052e3 PMF	2	#define _UST_TRACEPOINT_H
f99be407 PMF	3
f99be407 PMF	4	/*
1f8b0dff PMF	5	* Copyright (C) 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
1f8b0dff PMF	6	* Copyright (C) 2009 Pierre-Marc Fournier
22d72948	7	* Copyright (C) 2009 Steven Rostedt <rostedt@goodmis.org>
f99be407	8	*
8fc2d8db PMF	9	* This library is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU Lesser General Public
	11	* License as published by the Free Software Foundation; either
	12	* version 2.1 of the License, or (at your option) any later version.
f99be407	13	*
8fc2d8db	14	* This library is distributed in the hope that it will be useful,
1f8b0dff	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
8fc2d8db PMF	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
8fc2d8db PMF	17	* Lesser General Public License for more details.
1f8b0dff	18	*
8fc2d8db PMF	19	* You should have received a copy of the GNU Lesser General Public
	20	* License along with this library; if not, write to the Free Software
	21	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
f99be407 PMF	22	*
	23	* Heavily inspired from the Linux Kernel Markers.
	24	*
1f8b0dff	25	* Ported to userspace by Pierre-Marc Fournier.
f99be407 PMF	26	*/
f99be407 PMF	27
872037bb	28	#define _LGPL_SOURCE
b7ea1a1c	29	#include <urcu-bp.h>
93d0f2ea	30	#include <ust/immediate.h>
518d7abb	31	#include <ust/core.h>
f99be407 PMF	32
	33	struct module;
	34	struct tracepoint;
	35
9dec086e NC	36	struct probe {
	37	void *func;
	38	void *data;
	39	};
	40
f99be407 PMF	41	struct tracepoint {
	42	const char name; / Tracepoint name */
	43	DEFINE_IMV(char, state); /* State. */
9dec086e	44	struct probe *probes;
f218ff28	45	};
f99be407	46
22d72948 NC	47	#define PARAMS(args...) args
22d72948 NC	48
7166e240 PMF	49	#define TP_PROTO(args...) args
7166e240 PMF	50	#define TP_ARGS(args...) args
f99be407	51
872037bb PMF	52	#define CONFIG_TRACEPOINTS
872037bb PMF	53	#ifdef CONFIG_TRACEPOINTS
f99be407 PMF	54
	55	/*
	56	* it_func[0] is never NULL because there is at least one element in the array
	57	* when the array itself is non NULL.
	58	*/
	59	#define __DO_TRACE(tp, proto, args) \
	60	do { \
9dec086e NC	61	struct probe *it_probe_ptr; \
	62	void *it_func; \
	63	void *__data; \
f99be407	64	\
9dec086e NC	65	rcu_read_lock(); \
	66	it_probe_ptr = rcu_dereference((tp)->probes); \
	67	if (it_probe_ptr) { \
f99be407	68	do { \
9dec086e NC	69	it_func = (it_probe_ptr)->func; \
	70	__data = (it_probe_ptr)->data; \
	71	((void(*)(proto))(it_func))(args); \
	72	} while ((++it_probe_ptr)->func); \
f99be407	73	} \
9dec086e	74	rcu_read_unlock(); \
f99be407 PMF	75	} while (0)
	76
	77	#define __CHECK_TRACE(name, generic, proto, args) \
	78	do { \
	79	if (!generic) { \
	80	if (unlikely(imv_read(__tracepoint_##name.state))) \
	81	__DO_TRACE(&__tracepoint_##name, \
7166e240	82	TP_PROTO(proto), TP_ARGS(args)); \
f99be407 PMF	83	} else { \
	84	if (unlikely(_imv_read(__tracepoint_##name.state))) \
	85	__DO_TRACE(&__tracepoint_##name, \
7166e240	86	TP_PROTO(proto), TP_ARGS(args)); \
f99be407 PMF	87	} \
	88	} while (0)
	89
	90	/*
	91	* Make sure the alignment of the structure in the __tracepoints section will
	92	* not add unwanted padding between the beginning of the section and the
	93	* structure. Force alignment to the same alignment as the section start.
	94	*
	95	* The "generic" argument, passed to the declared __trace_##name inline
	96	* function controls which tracepoint enabling mechanism must be used.
	97	* If generic is true, a variable read is used.
	98	* If generic is false, immediate values are used.
	99	*/
9dec086e	100	#define __DECLARE_TRACE(name, proto, args, data_proto, data_args) \
f99be407 PMF	101	extern struct tracepoint __tracepoint_##name; \
	102	static inline void trace_##name(proto) \
	103	{ \
9dec086e NC	104	__CHECK_TRACE(name, 0, TP_PROTO(data_proto), \
9dec086e NC	105	TP_ARGS(data_args)); \
f99be407 PMF	106	} \
	107	static inline void _trace_##name(proto) \
	108	{ \
9dec086e NC	109	__CHECK_TRACE(name, 1, TP_PROTO(data_proto), \
9dec086e NC	110	TP_ARGS(data_args)); \
f99be407	111	} \
9dec086e NC	112	static inline int \
9dec086e NC	113	register_trace_##name(void (probe)(data_proto), void data) \
f99be407	114	{ \
9dec086e NC	115	return tracepoint_probe_register(#name, (void *)probe, \
	116	data); \
	117	\
f99be407	118	} \
9dec086e NC	119	static inline int \
9dec086e NC	120	unregister_trace_##name(void (probe)(data_proto), void data) \
f99be407	121	{ \
9dec086e NC	122	return tracepoint_probe_unregister(#name, (void *)probe, \
9dec086e NC	123	data); \
f99be407 PMF	124	}
f99be407 PMF	125
f218ff28	126	#define DEFINE_TRACE_FN(name, reg, unreg) \
f99be407 PMF	127	static const char __tpstrtab_##name[] \
	128	__attribute__((section("__tracepoints_strings"))) = #name; \
	129	struct tracepoint __tracepoint_##name \
f218ff28 MD	130	__attribute__((section("__tracepoints"))) = \
	131	{ __tpstrtab_##name, 0, NULL }; \
	132	static struct tracepoint * const __tracepoint_ptr_##name \
	133	__attribute__((used, section("__tracepoints_ptrs"))) = \
	134	&__tracepoint_##name;
f99be407	135
9dec086e	136	#define DEFINE_TRACE(name) \
f218ff28	137	DEFINE_TRACE_FN(name, NULL, NULL)
9dec086e	138
f218ff28 MD	139	extern void tracepoint_update_probe_range(struct tracepoint * const *begin,
f218ff28 MD	140	struct tracepoint * const *end);
f99be407	141
872037bb	142	#else /* !CONFIG_TRACEPOINTS */
9dec086e	143	#define __DECLARE_TRACE(name, proto, args) \
872037bb PMF	144	static inline void trace_##name(proto) \
	145	{ } \
	146	static inline void _trace_##name(proto) \
	147	{ } \
f218ff28	148	static inline int register_trace_##name(void (probe)(proto), void data) \
872037bb PMF	149	{ \
	150	return -ENOSYS; \
	151	} \
f218ff28	152	static inline int unregister_trace_##name(void (probe)(proto), void data) \
872037bb PMF	153	{ \
	154	return -ENOSYS; \
	155	}
	156
	157	#define DEFINE_TRACE(name)
	158	#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
	159	#define EXPORT_TRACEPOINT_SYMBOL(name)
	160
	161	static inline void tracepoint_update_probe_range(struct tracepoint *begin,
	162	struct tracepoint *end)
	163	{ }
	164	#endif /* CONFIG_TRACEPOINTS */
f99be407	165
9dec086e NC	166	#define DECLARE_TRACE(name, proto, args) \
	167	__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \
	168	PARAMS(void *__data, proto), \
	169	PARAMS(__data, args))
	170
f99be407 PMF	171	/*
	172	* Connect a probe to a tracepoint.
	173	* Internal API, should not be used directly.
	174	*/
9dec086e	175	extern int tracepoint_probe_register(const char name, void probe, void *data);
f99be407 PMF	176
	177	/*
	178	* Disconnect a probe from a tracepoint.
	179	* Internal API, should not be used directly.
	180	*/
9dec086e	181	extern int tracepoint_probe_unregister(const char name, void probe, void *data);
f99be407	182
9dec086e NC	183	extern int tracepoint_probe_register_noupdate(const char name, void probe,
	184	void *data);
	185	extern int tracepoint_probe_unregister_noupdate(const char name, void probe,
	186	void *data);
f99be407 PMF	187	extern void tracepoint_probe_update_all(void);
	188
	189	struct tracepoint_iter {
474d745f PMF	190	//ust// struct module *module;
474d745f PMF	191	struct tracepoint_lib *lib;
f218ff28	192	struct tracepoint * const *tracepoint;
f99be407 PMF	193	};
	194
	195	extern void tracepoint_iter_start(struct tracepoint_iter *iter);
	196	extern void tracepoint_iter_next(struct tracepoint_iter *iter);
	197	extern void tracepoint_iter_stop(struct tracepoint_iter *iter);
	198	extern void tracepoint_iter_reset(struct tracepoint_iter *iter);
f218ff28 MD	199	extern int tracepoint_get_iter_range(struct tracepoint * const **tracepoint,
f218ff28 MD	200	struct tracepoint * const begin, struct tracepoint const *end);
f99be407 PMF	201
	202	/*
	203	* tracepoint_synchronize_unregister must be called between the last tracepoint
	204	* probe unregistration and the end of module exit to make sure there is no
	205	* caller executing a probe when it is freed.
	206	*/
	207	static inline void tracepoint_synchronize_unregister(void)
	208	{
270c6b98	209	//ust// synchronize_sched();
f99be407 PMF	210	}
f99be407 PMF	211
474d745f	212	struct tracepoint_lib {
f218ff28	213	struct tracepoint * const *tracepoints_start;
474d745f	214	int tracepoints_count;
0222e121	215	struct cds_list_head list;
474d745f PMF	216	};
474d745f PMF	217
f218ff28	218	extern int tracepoint_register_lib(struct tracepoint * const *tracepoints_start,
872037bb	219	int tracepoints_count);
f218ff28	220	extern int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start);
872037bb PMF	221
872037bb PMF	222	#define TRACEPOINT_LIB \
bf5fe926 MD	223	extern struct tracepoint * const __start___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
	224	extern struct tracepoint * const __stop___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
	225	static void __attribute__((constructor)) __tracepoints__init(void) \
	226	{ \
103fffbc MD	227	tracepoint_register_lib(__start___tracepoints_ptrs, \
	228	__stop___tracepoints_ptrs - \
	229	__start___tracepoints_ptrs); \
bf5fe926 MD	230	} \
	231	\
	232	static void __attribute__((destructor)) __tracepoints__destroy(void) \
	233	{ \
103fffbc	234	tracepoint_unregister_lib(__start___tracepoints_ptrs); \
872037bb PMF	235	}
872037bb PMF	236
22d72948 NC	237
	238	#ifndef TRACE_EVENT
	239	/*
	240	* For use with the TRACE_EVENT macro:
	241	*
	242	* We define a tracepoint, its arguments, its printf format
	243	* and its 'fast binary record' layout.
	244	*
	245	* Firstly, name your tracepoint via TRACE_EVENT(name : the
	246	* 'subsystem_event' notation is fine.
	247	*
	248	* Think about this whole construct as the
	249	* 'trace_sched_switch() function' from now on.
	250	*
	251	*
	252	* TRACE_EVENT(sched_switch,
	253	*
	254	* *
	255	* * A function has a regular function arguments
	256	* * prototype, declare it via TP_PROTO():
	257	* *
	258	*
	259	* TP_PROTO(struct rq rq, struct task_struct prev,
	260	* struct task_struct *next),
	261	*
	262	* *
	263	* * Define the call signature of the 'function'.
	264	* * (Design sidenote: we use this instead of a
	265	* * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
	266	* *
	267	*
	268	* TP_ARGS(rq, prev, next),
	269	*
	270	* *
	271	* * Fast binary tracing: define the trace record via
	272	* * TP_STRUCT__entry(). You can think about it like a
	273	* * regular C structure local variable definition.
	274	* *
	275	* * This is how the trace record is structured and will
	276	* * be saved into the ring buffer. These are the fields
	277	* * that will be exposed to readers.
	278	* *
	279	* * The declared 'local variable' is called '__entry'
	280	* *
	281	* * __field(pid_t, prev_prid) is equivalent to a standard declariton:
	282	* *
	283	* * pid_t prev_pid;
	284	* *
	285	* * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
	286	* *
	287	* * char prev_comm[TASK_COMM_LEN];
	288	* *
	289	*
	290	* TP_STRUCT__entry(
	291	* __array( char, prev_comm, TASK_COMM_LEN )
	292	* __field( pid_t, prev_pid )
	293	* __field( int, prev_prio )
	294	* __array( char, next_comm, TASK_COMM_LEN )
	295	* __field( pid_t, next_pid )
	296	* __field( int, next_prio )
	297	* ),
	298	*
	299	* *
	300	* * Assign the entry into the trace record, by embedding
301	* * a full C statement block into TP_fast_assign(). You
302	* * can refer to the trace record as '__entry' -
303	* * otherwise you can put arbitrary C code in here.
304	* *
305	* * Note: this C code will execute every time a trace event
306	* * happens, on an active tracepoint.
307	* *
308	*
309	* TP_fast_assign(
310	* memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
311	* __entry->prev_pid = prev->pid;
312	* __entry->prev_prio = prev->prio;
313	* memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
314	* __entry->next_pid = next->pid;
315	* __entry->next_prio = next->prio;
316	* )
317	*
318	* *
319	* * Formatted output of a trace record via TP_printf().
320	* * This is how the tracepoint will appear under debugging
321	* * of tracepoints.
322	* *
323	* * (raw-binary tracing wont actually perform this step.)
324	* *
325	*
326	* TP_printf("task %s:%d [%d] ==> %s:%d [%d]",
327	* __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
328	* __entry->next_comm, __entry->next_pid, __entry->next_prio),
329	*
330	* );
331	*
332	* This macro construct is thus used for the regular printf format
333	* tracing setup.
334	*
335	* A set of (un)registration functions can be passed to the variant
336	* TRACE_EVENT_FN to perform any (un)registration work.
337	*/
338
0c0686ee NC	339	struct trace_event {
	340	const char *name;
	341	int (regfunc)(void data);
	342	int (unregfunc)(void data);
fc1caebc	343	};
0c0686ee NC	344
0c0686ee NC	345	struct trace_event_lib {
fc1caebc	346	struct trace_event * const *trace_events_start;
0c0686ee	347	int trace_events_count;
0222e121	348	struct cds_list_head list;
0c0686ee NC	349	};
	350
	351	struct trace_event_iter {
	352	struct trace_event_lib *lib;
fc1caebc	353	struct trace_event * const *trace_event;
0c0686ee NC	354	};
	355
	356	extern void lock_trace_events(void);
	357	extern void unlock_trace_events(void);
	358
	359	extern void trace_event_iter_start(struct trace_event_iter *iter);
	360	extern void trace_event_iter_next(struct trace_event_iter *iter);
	361	extern void trace_event_iter_reset(struct trace_event_iter *iter);
	362
fc1caebc MD	363	extern int trace_event_get_iter_range(struct trace_event * const **trace_event,
	364	struct trace_event * const *begin,
	365	struct trace_event * const *end);
0c0686ee NC	366
	367	extern void trace_event_update_process(void);
	368	extern int is_trace_event_enabled(const char channel, const char name);
	369
fc1caebc	370	extern int trace_event_register_lib(struct trace_event * const *start_trace_events,
0c0686ee NC	371	int trace_event_count);
0c0686ee NC	372
fc1caebc	373	extern int trace_event_unregister_lib(struct trace_event * const *start_trace_events);
0c0686ee NC	374
0c0686ee NC	375	#define TRACE_EVENT_LIB \
fc1caebc	376	extern struct trace_event * const __start___trace_events_ptrs[] \
0c0686ee	377	__attribute__((weak, visibility("hidden"))); \
fc1caebc	378	extern struct trace_event * const __stop___trace_events_ptrs[] \
0c0686ee NC	379	__attribute__((weak, visibility("hidden"))); \
	380	static void __attribute__((constructor)) \
	381	__trace_events__init(void) \
	382	{ \
fc1caebc MD	383	trace_event_register_lib(__start___trace_events_ptrs, \
	384	__stop___trace_events_ptrs - \
	385	__start___trace_events_ptrs); \
0c0686ee NC	386	} \
	387	\
	388	static void __attribute__((destructor)) \
	389	__trace_event__destroy(void) \
	390	{ \
fc1caebc	391	trace_event_unregister_lib(__start___trace_events_ptrs);\
0c0686ee NC	392	}
0c0686ee NC	393
22d72948 NC	394	#define DECLARE_TRACE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
	395	#define DEFINE_TRACE_EVENT(template, name, proto, args) \
	396	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
	397	#define DEFINE_TRACE_EVENT_PRINT(template, name, proto, args, print) \
	398	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
	399
	400	#define TRACE_EVENT(name, proto, args, struct, assign, print) \
	401	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
	402	#define TRACE_EVENT_FN(name, proto, args, struct, \
	403	assign, print, reg, unreg) \
	404	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
	405
	406	#endif /* ifdef TRACE_EVENT (see note above) */
	407
	408
27b052e3	409	#endif /* _UST_TRACEPOINT_H */