[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/core.h>

struct tracepoint;

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

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

#define PARAMS(args...) args

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

/*
 * Tracepoints should be added to the instrumented code using the
 * "tracepoint()" macro.
 */
#define tracepoint(name, args...)	__trace_##name(args)

#define register_tracepoint(name, probe, data)			\
		__register_trace_##name(probe, data)

#define unregister_tracepoint(name, probe, data)		\
		__unregister_trace_##name(probe, data)

#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, proto, args)				\
	do {								\
		if (unlikely(__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.
 */
#define __DECLARE_TRACE(name, proto, args, data_proto, data_args)	\
	extern struct tracepoint __tracepoint_##name;			\
	static inline void __trace_##name(proto)			\
	{								\
		__CHECK_TRACE(name, 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 */

/*
 * The need for the DECLARE_TRACE_NOARGS() is to handle the prototype
 * (void). "void" is a special value in a function prototype and can
 * not be combined with other arguments. Since the DECLARE_TRACE()
 * macro adds a data element at the beginning of the prototype,
 * we need a way to differentiate "(void *data, proto)" from
 * "(void *data, void)". The second prototype is invalid.
 *
 * DECLARE_TRACE_NOARGS() passes "void" as the tracepoint prototype
 * and "void *__data" as the callback prototype.
 *
 * DECLARE_TRACE() passes "proto" as the tracepoint protoype and
 * "void *__data, proto" as the callback prototype.
 */
#define DECLARE_TRACE_NOARGS(name)					\
		__DECLARE_TRACE(name, void, , void *__data, __data)

#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 {
	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 struct tracepoint * const __tracepoint_ptr_dummy		\
	__attribute__((used, section("__tracepoints_ptrs"))) = NULL;	\
	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 struct trace_event * const __event_ptrs_dummy		\
	__attribute__((used, section("__trace_events_ptrs"))) =	NULL;	\
	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>
518d7abb	30	#include <ust/core.h>
f99be407	31
f99be407 PMF	32	struct tracepoint;
f99be407 PMF	33
9dec086e NC	34	struct probe {
	35	void *func;
	36	void *data;
	37	};
	38
f99be407 PMF	39	struct tracepoint {
f99be407 PMF	40	const char name; / Tracepoint name */
f36c12ab	41	char state; /* State. */
9dec086e	42	struct probe *probes;
f218ff28	43	};
f99be407	44
22d72948 NC	45	#define PARAMS(args...) args
22d72948 NC	46
7166e240 PMF	47	#define TP_PROTO(args...) args
7166e240 PMF	48	#define TP_ARGS(args...) args
f99be407	49
cc7b66ba MD	50	/*
	51	* Tracepoints should be added to the instrumented code using the
	52	* "tracepoint()" macro.
	53	*/
	54	#define tracepoint(name, args...) __trace_##name(args)
	55
	56	#define register_tracepoint(name, probe, data) \
	57	__register_trace_##name(probe, data)
	58
	59	#define unregister_tracepoint(name, probe, data) \
	60	__unregister_trace_##name(probe, data)
	61
872037bb PMF	62	#define CONFIG_TRACEPOINTS
872037bb PMF	63	#ifdef CONFIG_TRACEPOINTS
f99be407 PMF	64
	65	/*
	66	* it_func[0] is never NULL because there is at least one element in the array
	67	* when the array itself is non NULL.
	68	*/
	69	#define __DO_TRACE(tp, proto, args) \
	70	do { \
9dec086e NC	71	struct probe *it_probe_ptr; \
	72	void *it_func; \
	73	void *__data; \
f99be407	74	\
9dec086e NC	75	rcu_read_lock(); \
	76	it_probe_ptr = rcu_dereference((tp)->probes); \
	77	if (it_probe_ptr) { \
f99be407	78	do { \
9dec086e NC	79	it_func = (it_probe_ptr)->func; \
	80	__data = (it_probe_ptr)->data; \
	81	((void(*)(proto))(it_func))(args); \
	82	} while ((++it_probe_ptr)->func); \
f99be407	83	} \
9dec086e	84	rcu_read_unlock(); \
f99be407 PMF	85	} while (0)
f99be407 PMF	86
f36c12ab	87	#define __CHECK_TRACE(name, proto, args) \
f99be407	88	do { \
f36c12ab MD	89	if (unlikely(__tracepoint_##name.state)) \
	90	__DO_TRACE(&__tracepoint_##name, \
	91	TP_PROTO(proto), TP_ARGS(args)); \
f99be407 PMF	92	} while (0)
	93
	94	/*
	95	* Make sure the alignment of the structure in the __tracepoints section will
	96	* not add unwanted padding between the beginning of the section and the
	97	* structure. Force alignment to the same alignment as the section start.
f99be407	98	*/
9dec086e	99	#define __DECLARE_TRACE(name, proto, args, data_proto, data_args) \
f99be407	100	extern struct tracepoint __tracepoint_##name; \
cc7b66ba	101	static inline void __trace_##name(proto) \
f99be407	102	{ \
f36c12ab	103	__CHECK_TRACE(name, TP_PROTO(data_proto), \
9dec086e	104	TP_ARGS(data_args)); \
f99be407	105	} \
9dec086e	106	static inline int \
cc7b66ba	107	__register_trace_##name(void (probe)(data_proto), void data) \
f99be407	108	{ \
9dec086e NC	109	return tracepoint_probe_register(#name, (void *)probe, \
	110	data); \
	111	\
f99be407	112	} \
9dec086e	113	static inline int \
cc7b66ba	114	__unregister_trace_##name(void (probe)(data_proto), void data)\
f99be407	115	{ \
9dec086e NC	116	return tracepoint_probe_unregister(#name, (void *)probe, \
9dec086e NC	117	data); \
f99be407 PMF	118	}
f99be407 PMF	119
f218ff28	120	#define DEFINE_TRACE_FN(name, reg, unreg) \
f99be407 PMF	121	static const char __tpstrtab_##name[] \
	122	__attribute__((section("__tracepoints_strings"))) = #name; \
	123	struct tracepoint __tracepoint_##name \
f218ff28 MD	124	__attribute__((section("__tracepoints"))) = \
	125	{ __tpstrtab_##name, 0, NULL }; \
	126	static struct tracepoint * const __tracepoint_ptr_##name \
	127	__attribute__((used, section("__tracepoints_ptrs"))) = \
	128	&__tracepoint_##name;
f99be407	129
9dec086e	130	#define DEFINE_TRACE(name) \
f218ff28	131	DEFINE_TRACE_FN(name, NULL, NULL)
9dec086e	132
f218ff28 MD	133	extern void tracepoint_update_probe_range(struct tracepoint * const *begin,
f218ff28 MD	134	struct tracepoint * const *end);
f99be407	135
872037bb	136	#else /* !CONFIG_TRACEPOINTS */
9dec086e	137	#define __DECLARE_TRACE(name, proto, args) \
872037bb PMF	138	static inline void trace_##name(proto) \
	139	{ } \
	140	static inline void _trace_##name(proto) \
	141	{ } \
cc7b66ba	142	static inline int __register_trace_##name(void (probe)(proto), void data) \
872037bb PMF	143	{ \
	144	return -ENOSYS; \
	145	} \
cc7b66ba	146	static inline int __unregister_trace_##name(void (probe)(proto), void data) \
872037bb PMF	147	{ \
	148	return -ENOSYS; \
	149	}
	150
	151	#define DEFINE_TRACE(name)
	152	#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
	153	#define EXPORT_TRACEPOINT_SYMBOL(name)
	154
	155	static inline void tracepoint_update_probe_range(struct tracepoint *begin,
	156	struct tracepoint *end)
	157	{ }
	158	#endif /* CONFIG_TRACEPOINTS */
f99be407	159
377d33ed MD	160	/*
	161	* The need for the DECLARE_TRACE_NOARGS() is to handle the prototype
	162	* (void). "void" is a special value in a function prototype and can
	163	* not be combined with other arguments. Since the DECLARE_TRACE()
	164	* macro adds a data element at the beginning of the prototype,
	165	* we need a way to differentiate "(void *data, proto)" from
	166	* "(void *data, void)". The second prototype is invalid.
	167	*
	168	* DECLARE_TRACE_NOARGS() passes "void" as the tracepoint prototype
	169	* and "void *__data" as the callback prototype.
	170	*
	171	* DECLARE_TRACE() passes "proto" as the tracepoint protoype and
	172	* "void *__data, proto" as the callback prototype.
	173	*/
	174	#define DECLARE_TRACE_NOARGS(name) \
	175	__DECLARE_TRACE(name, void, , void *__data, __data)
	176
	177	#define DECLARE_TRACE(name, proto, args) \
	178	__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \
	179	PARAMS(void *__data, proto), \
	180	PARAMS(__data, args))
9dec086e	181
f99be407 PMF	182	/*
	183	* Connect a probe to a tracepoint.
	184	* Internal API, should not be used directly.
	185	*/
9dec086e	186	extern int tracepoint_probe_register(const char name, void probe, void *data);
f99be407 PMF	187
	188	/*
	189	* Disconnect a probe from a tracepoint.
	190	* Internal API, should not be used directly.
	191	*/
9dec086e	192	extern int tracepoint_probe_unregister(const char name, void probe, void *data);
f99be407	193
9dec086e NC	194	extern int tracepoint_probe_register_noupdate(const char name, void probe,
	195	void *data);
	196	extern int tracepoint_probe_unregister_noupdate(const char name, void probe,
	197	void *data);
f99be407 PMF	198	extern void tracepoint_probe_update_all(void);
	199
	200	struct tracepoint_iter {
474d745f	201	struct tracepoint_lib *lib;
f218ff28	202	struct tracepoint * const *tracepoint;
f99be407 PMF	203	};
	204
	205	extern void tracepoint_iter_start(struct tracepoint_iter *iter);
	206	extern void tracepoint_iter_next(struct tracepoint_iter *iter);
	207	extern void tracepoint_iter_stop(struct tracepoint_iter *iter);
	208	extern void tracepoint_iter_reset(struct tracepoint_iter *iter);
f218ff28 MD	209	extern int tracepoint_get_iter_range(struct tracepoint * const **tracepoint,
f218ff28 MD	210	struct tracepoint * const begin, struct tracepoint const *end);
f99be407 PMF	211
	212	/*
	213	* tracepoint_synchronize_unregister must be called between the last tracepoint
	214	* probe unregistration and the end of module exit to make sure there is no
	215	* caller executing a probe when it is freed.
	216	*/
	217	static inline void tracepoint_synchronize_unregister(void)
	218	{
270c6b98	219	//ust// synchronize_sched();
f99be407 PMF	220	}
f99be407 PMF	221
474d745f	222	struct tracepoint_lib {
f218ff28	223	struct tracepoint * const *tracepoints_start;
474d745f	224	int tracepoints_count;
0222e121	225	struct cds_list_head list;
474d745f PMF	226	};
474d745f PMF	227
f218ff28	228	extern int tracepoint_register_lib(struct tracepoint * const *tracepoints_start,
872037bb	229	int tracepoints_count);
f218ff28	230	extern int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start);
872037bb PMF	231
872037bb PMF	232	#define TRACEPOINT_LIB \
bf5fe926 MD	233	extern struct tracepoint * const __start___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
bf5fe926 MD	234	extern struct tracepoint * const __stop___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
f08ebbe2 MD	235	static struct tracepoint * const __tracepoint_ptr_dummy \
f08ebbe2 MD	236	__attribute__((used, section("__tracepoints_ptrs"))) = NULL; \
bf5fe926 MD	237	static void __attribute__((constructor)) __tracepoints__init(void) \
bf5fe926 MD	238	{ \
103fffbc MD	239	tracepoint_register_lib(__start___tracepoints_ptrs, \
	240	__stop___tracepoints_ptrs - \
	241	__start___tracepoints_ptrs); \
bf5fe926 MD	242	} \
	243	\
	244	static void __attribute__((destructor)) __tracepoints__destroy(void) \
	245	{ \
103fffbc	246	tracepoint_unregister_lib(__start___tracepoints_ptrs); \
872037bb PMF	247	}
872037bb PMF	248
22d72948 NC	249
	250	#ifndef TRACE_EVENT
	251	/*
	252	* For use with the TRACE_EVENT macro:
	253	*
	254	* We define a tracepoint, its arguments, its printf format
	255	* and its 'fast binary record' layout.
	256	*
	257	* Firstly, name your tracepoint via TRACE_EVENT(name : the
	258	* 'subsystem_event' notation is fine.
	259	*
	260	* Think about this whole construct as the
	261	* 'trace_sched_switch() function' from now on.
	262	*
	263	*
	264	* TRACE_EVENT(sched_switch,
	265	*
	266	* *
	267	* * A function has a regular function arguments
	268	* * prototype, declare it via TP_PROTO():
	269	* *
	270	*
	271	* TP_PROTO(struct rq rq, struct task_struct prev,
	272	* struct task_struct *next),
	273	*
	274	* *
	275	* * Define the call signature of the 'function'.
	276	* * (Design sidenote: we use this instead of a
	277	* * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
	278	* *
	279	*
	280	* TP_ARGS(rq, prev, next),
	281	*
	282	* *
	283	* * Fast binary tracing: define the trace record via
	284	* * TP_STRUCT__entry(). You can think about it like a
	285	* * regular C structure local variable definition.
	286	* *
	287	* * This is how the trace record is structured and will
	288	* * be saved into the ring buffer. These are the fields
	289	* * that will be exposed to readers.
	290	* *
	291	* * The declared 'local variable' is called '__entry'
	292	* *
	293	* * __field(pid_t, prev_prid) is equivalent to a standard declariton:
	294	* *
	295	* * pid_t prev_pid;
	296	* *
	297	* * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
	298	* *
	299	* * char prev_comm[TASK_COMM_LEN];
	300	* *
	301	*
	302	* TP_STRUCT__entry(
	303	* __array( char, prev_comm, TASK_COMM_LEN )
	304	* __field( pid_t, prev_pid )
	305	* __field( int, prev_prio )
	306	* __array( char, next_comm, TASK_COMM_LEN )
	307	* __field( pid_t, next_pid )
	308	* __field( int, next_prio )
	309	* ),
	310	*
	311	* *
	312	* * Assign the entry into the trace record, by embedding
313	* * a full C statement block into TP_fast_assign(). You
314	* * can refer to the trace record as '__entry' -
315	* * otherwise you can put arbitrary C code in here.
316	* *
317	* * Note: this C code will execute every time a trace event
318	* * happens, on an active tracepoint.
319	* *
320	*
321	* TP_fast_assign(
322	* memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
323	* __entry->prev_pid = prev->pid;
324	* __entry->prev_prio = prev->prio;
325	* memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
326	* __entry->next_pid = next->pid;
327	* __entry->next_prio = next->prio;
328	* )
329	*
330	* *
331	* * Formatted output of a trace record via TP_printf().
332	* * This is how the tracepoint will appear under debugging
333	* * of tracepoints.
334	* *
335	* * (raw-binary tracing wont actually perform this step.)
336	* *
337	*
338	* TP_printf("task %s:%d [%d] ==> %s:%d [%d]",
339	* __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
340	* __entry->next_comm, __entry->next_pid, __entry->next_prio),
341	*
342	* );
343	*
344	* This macro construct is thus used for the regular printf format
345	* tracing setup.
346	*
347	* A set of (un)registration functions can be passed to the variant
348	* TRACE_EVENT_FN to perform any (un)registration work.
349	*/
350
0c0686ee NC	351	struct trace_event {
	352	const char *name;
	353	int (regfunc)(void data);
	354	int (unregfunc)(void data);
fc1caebc	355	};
0c0686ee NC	356
0c0686ee NC	357	struct trace_event_lib {
fc1caebc	358	struct trace_event * const *trace_events_start;
0c0686ee	359	int trace_events_count;
0222e121	360	struct cds_list_head list;
0c0686ee NC	361	};
	362
	363	struct trace_event_iter {
	364	struct trace_event_lib *lib;
fc1caebc	365	struct trace_event * const *trace_event;
0c0686ee NC	366	};
	367
	368	extern void lock_trace_events(void);
	369	extern void unlock_trace_events(void);
	370
	371	extern void trace_event_iter_start(struct trace_event_iter *iter);
	372	extern void trace_event_iter_next(struct trace_event_iter *iter);
	373	extern void trace_event_iter_reset(struct trace_event_iter *iter);
	374
fc1caebc MD	375	extern int trace_event_get_iter_range(struct trace_event * const **trace_event,
	376	struct trace_event * const *begin,
	377	struct trace_event * const *end);
0c0686ee NC	378
	379	extern void trace_event_update_process(void);
	380	extern int is_trace_event_enabled(const char channel, const char name);
	381
fc1caebc	382	extern int trace_event_register_lib(struct trace_event * const *start_trace_events,
0c0686ee NC	383	int trace_event_count);
0c0686ee NC	384
fc1caebc	385	extern int trace_event_unregister_lib(struct trace_event * const *start_trace_events);
0c0686ee NC	386
0c0686ee NC	387	#define TRACE_EVENT_LIB \
fc1caebc	388	extern struct trace_event * const __start___trace_events_ptrs[] \
0c0686ee	389	__attribute__((weak, visibility("hidden"))); \
fc1caebc	390	extern struct trace_event * const __stop___trace_events_ptrs[] \
0c0686ee	391	__attribute__((weak, visibility("hidden"))); \
f08ebbe2 MD	392	static struct trace_event * const __event_ptrs_dummy \
f08ebbe2 MD	393	__attribute__((used, section("__trace_events_ptrs"))) = NULL; \
0c0686ee NC	394	static void __attribute__((constructor)) \
	395	__trace_events__init(void) \
	396	{ \
fc1caebc MD	397	trace_event_register_lib(__start___trace_events_ptrs, \
	398	__stop___trace_events_ptrs - \
	399	__start___trace_events_ptrs); \
0c0686ee NC	400	} \
	401	\
	402	static void __attribute__((destructor)) \
	403	__trace_event__destroy(void) \
	404	{ \
fc1caebc	405	trace_event_unregister_lib(__start___trace_events_ptrs);\
0c0686ee NC	406	}
0c0686ee NC	407
22d72948 NC	408	#define DECLARE_TRACE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
	409	#define DEFINE_TRACE_EVENT(template, name, proto, args) \
	410	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
	411	#define DEFINE_TRACE_EVENT_PRINT(template, name, proto, args, print) \
	412	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
	413
	414	#define TRACE_EVENT(name, proto, args, struct, assign, print) \
	415	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
	416	#define TRACE_EVENT_FN(name, proto, args, struct, \
	417	assign, print, reg, unreg) \
	418	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
	419
	420	#endif /* ifdef TRACE_EVENT (see note above) */
	421
	422
27b052e3	423	#endif /* _UST_TRACEPOINT_H */