[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
 *
 * 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 tracepoint {
	const char *name;		/* Tracepoint name */
	DEFINE_IMV(char, state);	/* State. */
	void **funcs;
} __attribute__((aligned(32)));		/*
					 * Aligned on 32 bytes because it is
					 * globally visible and gcc happily
					 * align these on the structure size.
					 * Keep in sync with vmlinux.lds.h.
					 */

#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 {								\
		void **it_func;						\
									\
		rcu_read_lock(); /*ust rcu_read_lock_sched_notrace();	*/			\
		it_func = rcu_dereference((tp)->funcs);			\
		if (it_func) {						\
			do {						\
				((void(*)(proto))(*it_func))(args);	\
			} while (*(++it_func));				\
		}							\
		rcu_read_unlock(); /*ust rcu_read_unlock_sched_notrace(); */			\
	} 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)				\
	extern struct tracepoint __tracepoint_##name;			\
	static inline void trace_##name(proto)				\
	{								\
		__CHECK_TRACE(name, 0, TP_PROTO(proto), TP_ARGS(args));	\
	}								\
	static inline void _trace_##name(proto)				\
	{								\
		__CHECK_TRACE(name, 1, TP_PROTO(proto), TP_ARGS(args));	\
	}								\
	static inline int register_trace_##name(void (*probe)(proto))	\
	{								\
		return tracepoint_probe_register(#name, (void *)probe);	\
	}								\
	static inline int unregister_trace_##name(void (*probe)(proto))	\
	{								\
		return tracepoint_probe_unregister(#name, (void *)probe);\
	}

#define DEFINE_TRACE(name)						\
	static const char __tpstrtab_##name[]				\
	__attribute__((section("__tracepoints_strings"))) = #name;	\
	struct tracepoint __tracepoint_##name				\
	__attribute__((section("__tracepoints"), aligned(32))) =	\
		{ __tpstrtab_##name, 0, NULL }

extern void tracepoint_update_probe_range(struct tracepoint *begin,
	struct tracepoint *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))	\
	{								\
		return -ENOSYS;						\
	}								\
	static inline int unregister_trace_##name(void (*probe)(proto))	\
	{								\
		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 */

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

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

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

struct tracepoint_iter {
//ust//	struct module *module;
	struct tracepoint_lib *lib;
	struct tracepoint *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 **tracepoint,
	struct tracepoint *begin, struct tracepoint *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 *tracepoints_start;
	int tracepoints_count;
	struct list_head list;
};

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

#define TRACEPOINT_LIB							\
	extern struct tracepoint __start___tracepoints[] __attribute__((weak, visibility("hidden"))); \
	extern struct tracepoint __stop___tracepoints[] __attribute__((weak, visibility("hidden"))); \
	static void __attribute__((constructor)) __tracepoints__init(void) \
	{								\
		tracepoint_register_lib(__start___tracepoints,		\
					(((long)__stop___tracepoints)-((long)__start___tracepoints))/sizeof(struct tracepoint)); \
	} \
	\
	static void __attribute__((destructor)) __tracepoints__destroy(void) \
	{								\
		tracepoint_unregister_lib(__start___tracepoints); \
	}

#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
f99be407	7	*
8fc2d8db PMF	8	* This library is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License as published by the Free Software Foundation; either
	11	* version 2.1 of the License, or (at your option) any later version.
f99be407	12	*
8fc2d8db	13	* This library is distributed in the hope that it will be useful,
1f8b0dff	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
8fc2d8db PMF	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
8fc2d8db PMF	16	* Lesser General Public License for more details.
1f8b0dff	17	*
8fc2d8db PMF	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with this library; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
f99be407 PMF	21	*
	22	* Heavily inspired from the Linux Kernel Markers.
	23	*
1f8b0dff	24	* Ported to userspace by Pierre-Marc Fournier.
f99be407 PMF	25	*/
f99be407 PMF	26
872037bb	27	#define _LGPL_SOURCE
b7ea1a1c	28	#include <urcu-bp.h>
93d0f2ea	29	#include <ust/immediate.h>
518d7abb	30	#include <ust/core.h>
f99be407 PMF	31
	32	struct module;
	33	struct tracepoint;
	34
	35	struct tracepoint {
	36	const char name; / Tracepoint name */
	37	DEFINE_IMV(char, state); /* State. */
	38	void **funcs;
	39	} __attribute__((aligned(32))); /*
	40	* Aligned on 32 bytes because it is
	41	* globally visible and gcc happily
	42	* align these on the structure size.
	43	* Keep in sync with vmlinux.lds.h.
	44	*/
	45
7166e240 PMF	46	#define TP_PROTO(args...) args
7166e240 PMF	47	#define TP_ARGS(args...) args
f99be407	48
872037bb PMF	49	#define CONFIG_TRACEPOINTS
872037bb PMF	50	#ifdef CONFIG_TRACEPOINTS
f99be407 PMF	51
	52	/*
	53	* it_func[0] is never NULL because there is at least one element in the array
	54	* when the array itself is non NULL.
	55	*/
	56	#define __DO_TRACE(tp, proto, args) \
	57	do { \
	58	void **it_func; \
	59	\
6cb88bc0	60	rcu_read_lock(); /ust rcu_read_lock_sched_notrace(); / \
f99be407 PMF	61	it_func = rcu_dereference((tp)->funcs); \
	62	if (it_func) { \
	63	do { \
	64	((void()(proto))(it_func))(args); \
	65	} while (*(++it_func)); \
	66	} \
6cb88bc0	67	rcu_read_unlock(); /ust rcu_read_unlock_sched_notrace(); / \
f99be407 PMF	68	} while (0)
	69
	70	#define __CHECK_TRACE(name, generic, proto, args) \
	71	do { \
	72	if (!generic) { \
	73	if (unlikely(imv_read(__tracepoint_##name.state))) \
	74	__DO_TRACE(&__tracepoint_##name, \
7166e240	75	TP_PROTO(proto), TP_ARGS(args)); \
f99be407 PMF	76	} else { \
	77	if (unlikely(_imv_read(__tracepoint_##name.state))) \
	78	__DO_TRACE(&__tracepoint_##name, \
7166e240	79	TP_PROTO(proto), TP_ARGS(args)); \
f99be407 PMF	80	} \
	81	} while (0)
	82
	83	/*
	84	* Make sure the alignment of the structure in the __tracepoints section will
	85	* not add unwanted padding between the beginning of the section and the
	86	* structure. Force alignment to the same alignment as the section start.
	87	*
	88	* The "generic" argument, passed to the declared __trace_##name inline
	89	* function controls which tracepoint enabling mechanism must be used.
	90	* If generic is true, a variable read is used.
	91	* If generic is false, immediate values are used.
	92	*/
	93	#define DECLARE_TRACE(name, proto, args) \
	94	extern struct tracepoint __tracepoint_##name; \
	95	static inline void trace_##name(proto) \
	96	{ \
7166e240	97	__CHECK_TRACE(name, 0, TP_PROTO(proto), TP_ARGS(args)); \
f99be407 PMF	98	} \
	99	static inline void _trace_##name(proto) \
	100	{ \
7166e240	101	__CHECK_TRACE(name, 1, TP_PROTO(proto), TP_ARGS(args)); \
f99be407 PMF	102	} \
	103	static inline int register_trace_##name(void (*probe)(proto)) \
	104	{ \
	105	return tracepoint_probe_register(#name, (void *)probe); \
	106	} \
	107	static inline int unregister_trace_##name(void (*probe)(proto)) \
	108	{ \
	109	return tracepoint_probe_unregister(#name, (void *)probe);\
	110	}
	111
	112	#define DEFINE_TRACE(name) \
	113	static const char __tpstrtab_##name[] \
	114	__attribute__((section("__tracepoints_strings"))) = #name; \
	115	struct tracepoint __tracepoint_##name \
	116	__attribute__((section("__tracepoints"), aligned(32))) = \
	117	{ __tpstrtab_##name, 0, NULL }
	118
f99be407 PMF	119	extern void tracepoint_update_probe_range(struct tracepoint *begin,
	120	struct tracepoint *end);
	121
872037bb PMF	122	#else /* !CONFIG_TRACEPOINTS */
	123	#define DECLARE_TRACE(name, proto, args) \
	124	static inline void trace_##name(proto) \
	125	{ } \
	126	static inline void _trace_##name(proto) \
	127	{ } \
	128	static inline int register_trace_##name(void (*probe)(proto)) \
	129	{ \
	130	return -ENOSYS; \
	131	} \
	132	static inline int unregister_trace_##name(void (*probe)(proto)) \
	133	{ \
	134	return -ENOSYS; \
	135	}
	136
	137	#define DEFINE_TRACE(name)
	138	#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
	139	#define EXPORT_TRACEPOINT_SYMBOL(name)
	140
	141	static inline void tracepoint_update_probe_range(struct tracepoint *begin,
	142	struct tracepoint *end)
	143	{ }
	144	#endif /* CONFIG_TRACEPOINTS */
f99be407 PMF	145
	146	/*
	147	* Connect a probe to a tracepoint.
	148	* Internal API, should not be used directly.
	149	*/
	150	extern int tracepoint_probe_register(const char name, void probe);
	151
	152	/*
	153	* Disconnect a probe from a tracepoint.
	154	* Internal API, should not be used directly.
	155	*/
	156	extern int tracepoint_probe_unregister(const char name, void probe);
	157
	158	extern int tracepoint_probe_register_noupdate(const char name, void probe);
	159	extern int tracepoint_probe_unregister_noupdate(const char name, void probe);
	160	extern void tracepoint_probe_update_all(void);
	161
	162	struct tracepoint_iter {
474d745f PMF	163	//ust// struct module *module;
474d745f PMF	164	struct tracepoint_lib *lib;
f99be407 PMF	165	struct tracepoint *tracepoint;
	166	};
	167
	168	extern void tracepoint_iter_start(struct tracepoint_iter *iter);
	169	extern void tracepoint_iter_next(struct tracepoint_iter *iter);
	170	extern void tracepoint_iter_stop(struct tracepoint_iter *iter);
	171	extern void tracepoint_iter_reset(struct tracepoint_iter *iter);
	172	extern int tracepoint_get_iter_range(struct tracepoint **tracepoint,
	173	struct tracepoint begin, struct tracepoint end);
	174
	175	/*
	176	* tracepoint_synchronize_unregister must be called between the last tracepoint
	177	* probe unregistration and the end of module exit to make sure there is no
	178	* caller executing a probe when it is freed.
	179	*/
	180	static inline void tracepoint_synchronize_unregister(void)
	181	{
270c6b98	182	//ust// synchronize_sched();
f99be407 PMF	183	}
f99be407 PMF	184
474d745f PMF	185	struct tracepoint_lib {
	186	struct tracepoint *tracepoints_start;
	187	int tracepoints_count;
	188	struct list_head list;
	189	};
	190
872037bb PMF	191	extern int tracepoint_register_lib(struct tracepoint *tracepoints_start,
872037bb PMF	192	int tracepoints_count);
24b6668c	193	extern int tracepoint_unregister_lib(struct tracepoint *tracepoints_start);
872037bb PMF	194
872037bb PMF	195	#define TRACEPOINT_LIB \
55994a67 JB	196	extern struct tracepoint __start___tracepoints[] __attribute__((weak, visibility("hidden"))); \
55994a67 JB	197	extern struct tracepoint __stop___tracepoints[] __attribute__((weak, visibility("hidden"))); \
872037bb PMF	198	static void __attribute__((constructor)) __tracepoints__init(void) \
	199	{ \
	200	tracepoint_register_lib(__start___tracepoints, \
	201	(((long)__stop___tracepoints)-((long)__start___tracepoints))/sizeof(struct tracepoint)); \
24b6668c PMF	202	} \
	203	\
	204	static void __attribute__((destructor)) __tracepoints__destroy(void) \
	205	{ \
	206	tracepoint_unregister_lib(__start___tracepoints); \
872037bb PMF	207	}
872037bb PMF	208
27b052e3	209	#endif /* _UST_TRACEPOINT_H */