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

#ifndef _LINUX_TRACEPOINT_H
#define _LINUX_TRACEPOINT_H

/*
 * Copyright (C) 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
 * Copyright (C) 2009 Pierre-Marc Fournier
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; 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.
 */

//#include <linux/immediate.h>
//#include <linux/types.h>
//#include <linux/rcupdate.h>

#define _LGPL_SOURCE
#include <urcu.h>

#include "immediate.h"
#include "kernelcompat.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 TPPROTO(args...)	args
#define TPARGS(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,	\
					TPPROTO(proto), TPARGS(args));	\
		} else {						\
			if (unlikely(_imv_read(__tracepoint_##name.state))) \
				__DO_TRACE(&__tracepoint_##name,	\
					TPPROTO(proto), TPARGS(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, TPPROTO(proto), TPARGS(args));	\
	}								\
	static inline void _trace_##name(proto)				\
	{								\
		__CHECK_TRACE(name, 1, TPPROTO(proto), TPARGS(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 }

#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)				\
	EXPORT_SYMBOL_GPL(__tracepoint_##name)
#define EXPORT_TRACEPOINT_SYMBOL(name)					\
	EXPORT_SYMBOL(__tracepoint_##name)

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);

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

#endif
Commit	Line	Data
	1	#ifndef _LINUX_TRACEPOINT_H
	2	#define _LINUX_TRACEPOINT_H
	3
	4	/*
	5	* Copyright (C) 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
	6	* Copyright (C) 2009 Pierre-Marc Fournier
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License
	10	* as published by the Free Software Foundation; either version 2
	11	* of the License, or (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	21	*
	22	* Heavily inspired from the Linux Kernel Markers.
	23	*
	24	* Ported to userspace by Pierre-Marc Fournier.
	25	*/
	26
	27	//#include <linux/immediate.h>
	28	//#include <linux/types.h>
	29	//#include <linux/rcupdate.h>
	30
	31	#define _LGPL_SOURCE
	32	#include <urcu.h>
	33
	34	#include "immediate.h"
	35	#include "kernelcompat.h"
	36
	37	struct module;
	38	struct tracepoint;
	39
	40	struct tracepoint {
	41	const char name; / Tracepoint name */
	42	DEFINE_IMV(char, state); /* State. */
	43	void **funcs;
	44	} __attribute__((aligned(32))); /*
	45	* Aligned on 32 bytes because it is
	46	* globally visible and gcc happily
	47	* align these on the structure size.
	48	* Keep in sync with vmlinux.lds.h.
	49	*/
	50
	51	#define TPPROTO(args...) args
	52	#define TPARGS(args...) args
	53
	54	#define CONFIG_TRACEPOINTS
	55	#ifdef CONFIG_TRACEPOINTS
	56
	57	/*
	58	* it_func[0] is never NULL because there is at least one element in the array
	59	* when the array itself is non NULL.
	60	*/
	61	#define __DO_TRACE(tp, proto, args) \
	62	do { \
	63	void **it_func; \
	64	\
	65	rcu_read_lock(); /ust rcu_read_lock_sched_notrace(); / \
	66	it_func = rcu_dereference((tp)->funcs); \
	67	if (it_func) { \
	68	do { \
	69	((void()(proto))(it_func))(args); \
	70	} while (*(++it_func)); \
	71	} \
	72	rcu_read_unlock(); /ust rcu_read_unlock_sched_notrace(); / \
	73	} while (0)
	74
	75	#define __CHECK_TRACE(name, generic, proto, args) \
	76	do { \
	77	if (!generic) { \
	78	if (unlikely(imv_read(__tracepoint_##name.state))) \
	79	__DO_TRACE(&__tracepoint_##name, \
	80	TPPROTO(proto), TPARGS(args)); \
	81	} else { \
	82	if (unlikely(_imv_read(__tracepoint_##name.state))) \
	83	__DO_TRACE(&__tracepoint_##name, \
	84	TPPROTO(proto), TPARGS(args)); \
	85	} \
	86	} while (0)
	87
	88	/*
	89	* Make sure the alignment of the structure in the __tracepoints section will
	90	* not add unwanted padding between the beginning of the section and the
	91	* structure. Force alignment to the same alignment as the section start.
	92	*
	93	* The "generic" argument, passed to the declared __trace_##name inline
	94	* function controls which tracepoint enabling mechanism must be used.
	95	* If generic is true, a variable read is used.
	96	* If generic is false, immediate values are used.
	97	*/
	98	#define DECLARE_TRACE(name, proto, args) \
	99	extern struct tracepoint __tracepoint_##name; \
	100	static inline void trace_##name(proto) \
	101	{ \
	102	__CHECK_TRACE(name, 0, TPPROTO(proto), TPARGS(args)); \
	103	} \
	104	static inline void _trace_##name(proto) \
	105	{ \
	106	__CHECK_TRACE(name, 1, TPPROTO(proto), TPARGS(args)); \
	107	} \
	108	static inline int register_trace_##name(void (*probe)(proto)) \
	109	{ \
	110	return tracepoint_probe_register(#name, (void *)probe); \
	111	} \
	112	static inline int unregister_trace_##name(void (*probe)(proto)) \
	113	{ \
	114	return tracepoint_probe_unregister(#name, (void *)probe);\
	115	}
	116
	117	#define DEFINE_TRACE(name) \
	118	static const char __tpstrtab_##name[] \
	119	__attribute__((section("__tracepoints_strings"))) = #name; \
	120	struct tracepoint __tracepoint_##name \
	121	__attribute__((section("__tracepoints"), aligned(32))) = \
	122	{ __tpstrtab_##name, 0, NULL }
	123
	124	#define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \
	125	EXPORT_SYMBOL_GPL(__tracepoint_##name)
	126	#define EXPORT_TRACEPOINT_SYMBOL(name) \
	127	EXPORT_SYMBOL(__tracepoint_##name)
	128
	129	extern void tracepoint_update_probe_range(struct tracepoint *begin,
	130	struct tracepoint *end);
	131
	132	#else /* !CONFIG_TRACEPOINTS */
	133	#define DECLARE_TRACE(name, proto, args) \
	134	static inline void trace_##name(proto) \
	135	{ } \
	136	static inline void _trace_##name(proto) \
	137	{ } \
	138	static inline int register_trace_##name(void (*probe)(proto)) \
	139	{ \
	140	return -ENOSYS; \
	141	} \
	142	static inline int unregister_trace_##name(void (*probe)(proto)) \
	143	{ \
	144	return -ENOSYS; \
	145	}
	146
	147	#define DEFINE_TRACE(name)
	148	#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
	149	#define EXPORT_TRACEPOINT_SYMBOL(name)
	150
	151	static inline void tracepoint_update_probe_range(struct tracepoint *begin,
	152	struct tracepoint *end)
	153	{ }
	154	#endif /* CONFIG_TRACEPOINTS */
	155
	156	/*
	157	* Connect a probe to a tracepoint.
	158	* Internal API, should not be used directly.
	159	*/
	160	extern int tracepoint_probe_register(const char name, void probe);
	161
	162	/*
	163	* Disconnect a probe from a tracepoint.
	164	* Internal API, should not be used directly.
	165	*/
	166	extern int tracepoint_probe_unregister(const char name, void probe);
	167
	168	extern int tracepoint_probe_register_noupdate(const char name, void probe);
	169	extern int tracepoint_probe_unregister_noupdate(const char name, void probe);
	170	extern void tracepoint_probe_update_all(void);
	171
	172	struct tracepoint_iter {
	173	//ust// struct module *module;
	174	struct tracepoint_lib *lib;
	175	struct tracepoint *tracepoint;
	176	};
	177
	178	extern void tracepoint_iter_start(struct tracepoint_iter *iter);
	179	extern void tracepoint_iter_next(struct tracepoint_iter *iter);
	180	extern void tracepoint_iter_stop(struct tracepoint_iter *iter);
	181	extern void tracepoint_iter_reset(struct tracepoint_iter *iter);
	182	extern int tracepoint_get_iter_range(struct tracepoint **tracepoint,
	183	struct tracepoint begin, struct tracepoint end);
	184
	185	/*
	186	* tracepoint_synchronize_unregister must be called between the last tracepoint
	187	* probe unregistration and the end of module exit to make sure there is no
	188	* caller executing a probe when it is freed.
	189	*/
	190	static inline void tracepoint_synchronize_unregister(void)
	191	{
	192	//ust// synchronize_sched();
	193	}
	194
	195	struct tracepoint_lib {
	196	struct tracepoint *tracepoints_start;
	197	int tracepoints_count;
	198	struct list_head list;
	199	};
	200
	201	extern int tracepoint_register_lib(struct tracepoint *tracepoints_start,
	202	int tracepoints_count);
	203
	204	#define TRACEPOINT_LIB \
	205	extern struct tracepoint __start___tracepoints[] __attribute__((visibility("hidden"))); \
	206	extern struct tracepoint __stop___tracepoints[] __attribute__((visibility("hidden"))); \
	207	static void __attribute__((constructor)) __tracepoints__init(void) \
	208	{ \
	209	tracepoint_register_lib(__start___tracepoints, \
	210	(((long)__stop___tracepoints)-((long)__start___tracepoints))/sizeof(struct tracepoint)); \
	211	}
	212
	213	#endif