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

#ifndef _LTTNG_TRACEPOINT_H
#define _LTTNG_TRACEPOINT_H

/*
 * Copyright (c) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
 * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
 *
 * Permission is hereby granted to use or copy this program
 * for any purpose,  provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 */

#include <lttng/tracepoint-types.h>
#include <lttng/tracepoint-rcu.h>
#include <urcu/compiler.h>
#include <dlfcn.h>	/* for dlopen */
#include <string.h>	/* for memset */
#include <assert.h>
#include <lttng/ust-config.h>	/* for sdt */

#ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
#define SDT_USE_VARIADIC
#include <sys/sdt.h>
#else
#define STAP_PROBEV(...)
#endif

#ifdef __cplusplus
extern "C" {
#endif

#define tracepoint(provider, name, ...)					    \
	do {								    \
		STAP_PROBEV(provider, name, ## __VA_ARGS__);		    \
		if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
			__tracepoint_cb_##provider##___##name(__VA_ARGS__); \
	} while (0)

#define TP_ARGS(...)       __VA_ARGS__

/*
 * TP_ARGS takes tuples of type, argument separated by a comma.
 * It can take up to 10 tuples (which means that less than 10 tuples is
 * fine too).
 * Each tuple is also separated by a comma.
 */
#define __TP_COMBINE_TOKENS(_tokena, _tokenb)				\
		_tokena##_tokenb
#define _TP_COMBINE_TOKENS(_tokena, _tokenb)				\
		__TP_COMBINE_TOKENS(_tokena, _tokenb)
#define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)			\
		_tokena##_tokenb##_tokenc
#define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)			\
		__TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
#define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)	\
		_tokena##_tokenb##_tokenc##_tokend
#define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)		\
		__TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)

/* _TP_EXVAR* extract the var names. */
#define _TP_EXVAR0()
#define _TP_EXVAR2(a,b)						b
#define _TP_EXVAR4(a,b,c,d)					b,d
#define _TP_EXVAR6(a,b,c,d,e,f)					b,d,f
#define _TP_EXVAR8(a,b,c,d,e,f,g,h)				b,d,f,h
#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j)			b,d,f,h,j
#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l)			b,d,f,h,j,l
#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n)		b,d,f,h,j,l,n
#define _TP_EXVAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p)		b,d,f,h,j,l,n,p
#define _TP_EXVAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r)	b,d,f,h,j,l,n,p,r
#define _TP_EXVAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t)	b,d,f,h,j,l,n,p,r,t

#define _TP_EXDATA_VAR0()						__tp_data
#define _TP_EXDATA_VAR2(a,b)						__tp_data,b
#define _TP_EXDATA_VAR4(a,b,c,d)					__tp_data,b,d
#define _TP_EXDATA_VAR6(a,b,c,d,e,f)					__tp_data,b,d,f
#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h)				__tp_data,b,d,f,h
#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j)				__tp_data,b,d,f,h,j
#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l)			__tp_data,b,d,f,h,j,l
#define _TP_EXDATA_VAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n)			__tp_data,b,d,f,h,j,l,n
#define _TP_EXDATA_VAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p)		__tp_data,b,d,f,h,j,l,n,p
#define _TP_EXDATA_VAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r)		__tp_data,b,d,f,h,j,l,n,p,r
#define _TP_EXDATA_VAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t)	__tp_data,b,d,f,h,j,l,n,p,r,t

/* _TP_EXPROTO* extract tuples of type, var */
#define _TP_EXPROTO0()
#define _TP_EXPROTO2(a,b)					a b
#define _TP_EXPROTO4(a,b,c,d)					a b,c d
#define _TP_EXPROTO6(a,b,c,d,e,f)				a b,c d,e f
#define _TP_EXPROTO8(a,b,c,d,e,f,g,h)				a b,c d,e f,g h
#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j)			a b,c d,e f,g h,i j
#define _TP_EXPROTO12(a,b,c,d,e,f,g,h,i,j,k,l)			a b,c d,e f,g h,i j,k l
#define _TP_EXPROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n)		a b,c d,e f,g h,i j,k l,m n
#define _TP_EXPROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p)		a b,c d,e f,g h,i j,k l,m n,o p
#define _TP_EXPROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r)	a b,c d,e f,g h,i j,k l,m n,o p,q r
#define _TP_EXPROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t)	a b,c d,e f,g h,i j,k l,m n,o p,q r,s t

#define _TP_EXDATA_PROTO0()						void *__tp_data
#define _TP_EXDATA_PROTO2(a,b)						void *__tp_data,a b
#define _TP_EXDATA_PROTO4(a,b,c,d)					void *__tp_data,a b,c d
#define _TP_EXDATA_PROTO6(a,b,c,d,e,f)					void *__tp_data,a b,c d,e f
#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h)				void *__tp_data,a b,c d,e f,g h
#define _TP_EXDATA_PROTO10(a,b,c,d,e,f,g,h,i,j)				void *__tp_data,a b,c d,e f,g h,i j
#define _TP_EXDATA_PROTO12(a,b,c,d,e,f,g,h,i,j,k,l)			void *__tp_data,a b,c d,e f,g h,i j,k l
#define _TP_EXDATA_PROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n)			void *__tp_data,a b,c d,e f,g h,i j,k l,m n
#define _TP_EXDATA_PROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p)		void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p
#define _TP_EXDATA_PROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r)		void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r
#define _TP_EXDATA_PROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t)	void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r,s t

/* Preprocessor trick to count arguments. Inspired from sdt.h. */
#define _TP_NARGS(...)			__TP_NARGS(__VA_ARGS__, 20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
#define __TP_NARGS(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20, N, ...)	N
#define _TP_PROTO_N(N, ...)		_TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
#define _TP_VAR_N(N, ...)		_TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
#define _TP_DATA_PROTO_N(N, ...)	_TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
#define _TP_DATA_VAR_N(N, ...)		_TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
#define _TP_ARGS_PROTO(...)		_TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
#define _TP_ARGS_VAR(...)		_TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
#define _TP_ARGS_DATA_PROTO(...)	_TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
#define _TP_ARGS_DATA_VAR(...)		_TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
#define _TP_PARAMS(...)			__VA_ARGS__

#define _DECLARE_TRACEPOINT(_provider, _name, ...)			 		\
extern struct tracepoint __tracepoint_##_provider##___##_name;				\
static inline void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__))	\
{											\
	struct tracepoint_probe *__tp_probe;						\
											\
	if (!TP_RCU_LINK_TEST())							\
		return;									\
	tp_rcu_read_lock_bp();								\
	__tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
	if (caa_unlikely(!__tp_probe))							\
		goto end;								\
	do {										\
		void *__tp_cb =	__tp_probe->func;					\
		void *__tp_data = __tp_probe->data;					\
											\
		URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb)	\
				(_TP_ARGS_DATA_VAR(__VA_ARGS__));			\
	} while ((++__tp_probe)->func);							\
end:											\
	tp_rcu_read_unlock_bp();							\
}											\
static inline void __tracepoint_register_##_provider##___##_name(char *name,		\
		void *func, void *data)							\
{											\
	__tracepoint_probe_register(name, func, data);					\
}											\
static inline void __tracepoint_unregister_##_provider##___##_name(char *name,		\
		void *func, void *data)							\
{											\
	__tracepoint_probe_unregister(name, func, data);				\
}

extern int __tracepoint_probe_register(const char *name, void *func, void *data);
extern int __tracepoint_probe_unregister(const char *name, void *func, void *data);

/*
 * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
 * shared across objects in a module/main executable.
 */
struct tracepoint_dlopen {
	void *liblttngust_handle;

	int (*tracepoint_register_lib)(struct tracepoint * const *tracepoints_start,
		int tracepoints_count);
	int (*tracepoint_unregister_lib)(struct tracepoint * const *tracepoints_start);
#ifndef _LGPL_SOURCE
	void (*rcu_read_lock_sym_bp)(void);
	void (*rcu_read_unlock_sym_bp)(void);
	void *(*rcu_dereference_sym_bp)(void *p);
#endif
};

extern struct tracepoint_dlopen tracepoint_dlopen;

#ifdef TRACEPOINT_DEFINE

/*
 * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
 * unresolved symbol that requires the provider to be linked in. When
 * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
 * unresolved symbol that depends on having the provider linked in,
 * otherwise the linker complains. This deals with use of static
 * libraries, ensuring that the linker does not remove the provider
 * object from the executable.
 */
#ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
#define _TRACEPOINT_UNDEFINED_REF(provider)	NULL
#else	/* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
#define _TRACEPOINT_UNDEFINED_REF(provider)	&__tracepoint_provider_##provider
#endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */

/*
 * Note: to allow PIC code, we need to allow the linker to update the pointers
 * in the __tracepoints_ptrs section.
 * Therefore, this section is _not_ const (read-only).
 */
#define _TP_EXTRACT_STRING(...)	#__VA_ARGS__

#define _DEFINE_TRACEPOINT(_provider, _name, _args)				\
	extern int __tracepoint_provider_##_provider; 				\
	static const char __tp_strtab_##_provider##___##_name[]			\
		__attribute__((section("__tracepoints_strings"))) =		\
			#_provider ":" #_name;					\
	struct tracepoint __tracepoint_##_provider##___##_name			\
		__attribute__((section("__tracepoints"))) =			\
		{								\
			__tp_strtab_##_provider##___##_name,			\
			0,							\
			NULL,							\
			_TRACEPOINT_UNDEFINED_REF(_provider), 			\
			_TP_EXTRACT_STRING(_args),				\
		};								\
	static struct tracepoint * __tracepoint_ptr_##_provider##___##_name	\
		__attribute__((used, section("__tracepoints_ptrs"))) =		\
			&__tracepoint_##_provider##___##_name;

/*
 * These weak symbols, the constructor, and destructor take care of
 * registering only _one_ instance of the tracepoints per shared-ojbect
 * (or for the whole main program).
 */
extern struct tracepoint * const __start___tracepoints_ptrs[]
	__attribute__((weak, visibility("hidden")));
extern struct tracepoint * const __stop___tracepoints_ptrs[]
	__attribute__((weak, visibility("hidden")));
int __tracepoint_registered
	__attribute__((weak, visibility("hidden")));
struct tracepoint_dlopen tracepoint_dlopen
	__attribute__((weak, visibility("hidden")));

static void __attribute__((constructor)) __tracepoints__init(void)
{
	if (__tracepoint_registered++)
		return;

	tracepoint_dlopen.liblttngust_handle =
		dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
	if (!tracepoint_dlopen.liblttngust_handle)
		return;
	tracepoint_dlopen.tracepoint_register_lib =
		URCU_FORCE_CAST(int (*)(struct tracepoint * const *, int),
				dlsym(tracepoint_dlopen.liblttngust_handle,
					"tracepoint_register_lib"));
	tracepoint_dlopen.tracepoint_unregister_lib =
		URCU_FORCE_CAST(int (*)(struct tracepoint * const *),
				dlsym(tracepoint_dlopen.liblttngust_handle,
					"tracepoint_unregister_lib"));
#ifndef _LGPL_SOURCE
	tracepoint_dlopen.rcu_read_lock_sym_bp =
		URCU_FORCE_CAST(void (*)(void),
				dlsym(tracepoint_dlopen.liblttngust_handle,
					"tp_rcu_read_lock_bp"));
	tracepoint_dlopen.rcu_read_unlock_sym_bp =
		URCU_FORCE_CAST(void (*)(void),
				dlsym(tracepoint_dlopen.liblttngust_handle,
					"tp_rcu_read_unlock_bp"));
	tracepoint_dlopen.rcu_dereference_sym_bp =
		URCU_FORCE_CAST(void *(*)(void *p),
				dlsym(tracepoint_dlopen.liblttngust_handle,
					"tp_rcu_dereference_sym_bp"));
#endif
	tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs,
				__stop___tracepoints_ptrs -
				__start___tracepoints_ptrs);
}

static void __attribute__((destructor)) __tracepoints__destroy(void)
{
	int ret;

	if (--__tracepoint_registered)
		return;
	if (tracepoint_dlopen.tracepoint_unregister_lib)
		tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
	if (tracepoint_dlopen.liblttngust_handle) {
		ret = dlclose(tracepoint_dlopen.liblttngust_handle);
		assert(!ret);
		memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
	}
}

#else /* TRACEPOINT_DEFINE */

#define _DEFINE_TRACEPOINT(_provider, _name, _args)

#endif /* #else TRACEPOINT_DEFINE */

#ifdef __cplusplus
}
#endif

#endif /* _LTTNG_TRACEPOINT_H */

/* The following declarations must be outside re-inclusion protection. */

#ifndef TRACEPOINT_EVENT

/*
 * How to use the TRACEPOINT_EVENT macro:
 *
 * An example:
 * 
 * TRACEPOINT_EVENT(someproject_component, event_name,
 *
 *     * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
 *
 *     TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
 *             long *, arg4, size_t, arg4_len),
 *
 *	* TP_FIELDS describes the event payload layout in the trace *
 *
 *     TP_FIELDS(
 *         * Integer, printed in base 10 * 
 *         ctf_integer(int, field_a, arg0)
 *
 *         * Integer, printed with 0x base 16 * 
 *         ctf_integer_hex(unsigned long, field_d, arg1)
 *
 *         * Array Sequence, printed as UTF8-encoded array of bytes * 
 *         ctf_array_text(char, field_b, string, FIXED_LEN)
 *         ctf_sequence_text(char, field_c, string, size_t, strlen)
 *
 *         * String, printed as UTF8-encoded string * 
 *         ctf_string(field_e, string)
 *
 *         * Array sequence of signed integer values * 
 *         ctf_array(long, field_f, arg4, FIXED_LEN4)
 *         ctf_sequence(long, field_g, arg4, size_t, arg4_len)
 *     )
 * )
 *
 * More detailed explanation:
 *
 * The name of the tracepoint is expressed as a tuple with the provider
 * and name arguments.
 *
 * The provider and name should be a proper C99 identifier.
 * The "provider" and "name" MUST follow these rules to ensure no
 * namespace clash occurs:
 *
 * For projects (applications and libraries) for which an entity
 * specific to the project controls the source code and thus its
 * tracepoints (typically with a scope larger than a single company):
 *
 * either:
 *   project_component, event
 * or:
 *   project, event
 *
 * Where "project" is the name of the project,
 *       "component" is the name of the project component (which may
 *       include several levels of sub-components, e.g.
 *       ...component_subcomponent_...) where the tracepoint is located
 *       (optional),
 *       "event" is the name of the tracepoint event.
 *
 * For projects issued from a single company wishing to advertise that
 * the company controls the source code and thus the tracepoints, the
 * "com_" prefix should be used:
 *
 * either:
 *   com_company_project_component, event
 * or:
 *   com_company_project, event
 *
 * Where "company" is the name of the company,
 *       "project" is the name of the project,
 *       "component" is the name of the project component (which may
 *       include several levels of sub-components, e.g.
 *       ...component_subcomponent_...) where the tracepoint is located
 *       (optional),
 *       "event" is the name of the tracepoint event.
 *
 * the provider:event identifier is limited to 127 characters.
 */

#define TRACEPOINT_EVENT(provider, name, args, fields)			\
	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))		\
	_DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))

#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)

#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args)	\
	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))		\
	_DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))

#endif /* #ifndef TRACEPOINT_EVENT */

#ifndef TRACEPOINT_LOGLEVEL

/*
 * Tracepoint Loglevels
 *
 * Typical use of these loglevels:
 *
 * The loglevels go from 0 to 14. Higher numbers imply the most
 * verbosity (higher event throughput expected.
 *
 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
 * debug information.
 *
 * TRACE_EMERG           0
 * system is unusable
 *
 * TRACE_ALERT           1
 * action must be taken immediately
 *
 * TRACE_CRIT            2
 * critical conditions
 *
 * TRACE_ERR             3
 * error conditions
 *
 * TRACE_WARNING         4
 * warning conditions
 *
 * TRACE_NOTICE          5
 * normal, but significant, condition
 *
 * TRACE_INFO            6
 * informational message
 *
 * TRACE_DEBUG_SYSTEM    7
 * debug information with system-level scope (set of programs)
 *
 * TRACE_DEBUG_PROGRAM   8
 * debug information with program-level scope (set of processes)
 *
 * TRACE_DEBUG_PROCESS   9
 * debug information with process-level scope (set of modules)
 *
 * TRACE_DEBUG_MODULE    10
 * debug information with module (executable/library) scope (set of units)
 *
 * TRACE_DEBUG_UNIT      11
 * debug information with compilation unit scope (set of functions)
 *
 * TRACE_DEBUG_FUNCTION  12
 * debug information with function-level scope
 *
 * TRACE_DEBUG_LINE      13
 * debug information with line-level scope (TRACEPOINT_EVENT default)
 *
 * TRACE_DEBUG           14
 * debug-level message (trace_printf default)
 *
 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
 * tracepoint name. The first field is the provider name, the second
 * field is the name of the tracepoint, the third field is the loglevel
 * name.
 *
 *      TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
 *              < loglevel_name >)
 *
 * The TRACEPOINT_PROVIDER must be already declared before declaring a
 * TRACEPOINT_LOGLEVEL.
 */

enum {
	TRACE_EMERG		= 0,
	TRACE_ALERT		= 1,
	TRACE_CRIT		= 2,
	TRACE_ERR		= 3,
	TRACE_WARNING		= 4,
	TRACE_NOTICE		= 5,
	TRACE_INFO		= 6,
	TRACE_DEBUG_SYSTEM	= 7,
	TRACE_DEBUG_PROGRAM	= 8,
	TRACE_DEBUG_PROCESS	= 9,
	TRACE_DEBUG_MODULE	= 10,
	TRACE_DEBUG_UNIT	= 11,
	TRACE_DEBUG_FUNCTION	= 12,
	TRACE_DEBUG_LINE	= 13,
	TRACE_DEBUG		= 14,
};

#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)

#endif /* #ifndef TRACEPOINT_LOGLEVEL */
Commit	Line	Data
b728d87e MD	1	#ifndef _LTTNG_TRACEPOINT_H
	2	#define _LTTNG_TRACEPOINT_H
	3
	4	/*
	5	* Copyright (c) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	6	*
	7	* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
	8	* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
	9	*
	10	* Permission is hereby granted to use or copy this program
	11	* for any purpose, provided the above notices are retained on all copies.
	12	* Permission to modify the code and to distribute modified code is granted,
	13	* provided the above notices are retained, and a notice that the code was
	14	* modified is included with the above copyright notice.
	15	*/
	16
8fce9e2b	17	#include <lttng/tracepoint-types.h>
40b2b5a4	18	#include <lttng/tracepoint-rcu.h>
b728d87e	19	#include <urcu/compiler.h>
deb6e540	20	#include <dlfcn.h> /* for dlopen */
51920067	21	#include <string.h> /* for memset */
40b2b5a4	22	#include <assert.h>
b2f60c79 MD	23	#include <lttng/ust-config.h> /* for sdt */
	24
	25	#ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
	26	#define SDT_USE_VARIADIC
	27	#include <sys/sdt.h>
	28	#else
	29	#define STAP_PROBEV(...)
	30	#endif
b728d87e MD	31
	32	#ifdef __cplusplus
	33	extern "C" {
	34	#endif
	35
23c8854a MD	36	#define tracepoint(provider, name, ...) \
23c8854a MD	37	do { \
7cb85a18	38	STAP_PROBEV(provider, name, ## __VA_ARGS__); \
23c8854a MD	39	if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
23c8854a MD	40	__tracepoint_cb_##provider##___##name(__VA_ARGS__); \
b728d87e MD	41	} while (0)
	42
	43	#define TP_ARGS(...) __VA_ARGS__
	44
	45	/*
	46	* TP_ARGS takes tuples of type, argument separated by a comma.
	47	* It can take up to 10 tuples (which means that less than 10 tuples is
	48	* fine too).
	49	* Each tuple is also separated by a comma.
	50	*/
df854e41 MD	51	#define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
	52	_tokena##_tokenb
	53	#define _TP_COMBINE_TOKENS(_tokena, _tokenb) \
	54	__TP_COMBINE_TOKENS(_tokena, _tokenb)
	55	#define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
	56	_tokena##_tokenb##_tokenc
	57	#define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
	58	__TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
	59	#define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
	60	_tokena##_tokenb##_tokenc##_tokend
	61	#define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
	62	__TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
b728d87e	63
23c8854a	64	/* _TP_EXVAR* extract the var names. */
b728d87e MD	65	#define _TP_EXVAR0()
	66	#define _TP_EXVAR2(a,b) b
	67	#define _TP_EXVAR4(a,b,c,d) b,d
	68	#define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
	69	#define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
	70	#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
	71	#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
	72	#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
	73	#define _TP_EXVAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) b,d,f,h,j,l,n,p
	74	#define _TP_EXVAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) b,d,f,h,j,l,n,p,r
	75	#define _TP_EXVAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) b,d,f,h,j,l,n,p,r,t
	76
	77	#define _TP_EXDATA_VAR0() __tp_data
	78	#define _TP_EXDATA_VAR2(a,b) __tp_data,b
	79	#define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
	80	#define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
	81	#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
	82	#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
	83	#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
	84	#define _TP_EXDATA_VAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) __tp_data,b,d,f,h,j,l,n
	85	#define _TP_EXDATA_VAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) __tp_data,b,d,f,h,j,l,n,p
	86	#define _TP_EXDATA_VAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) __tp_data,b,d,f,h,j,l,n,p,r
	87	#define _TP_EXDATA_VAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) __tp_data,b,d,f,h,j,l,n,p,r,t
	88
	89	/* _TP_EXPROTO* extract tuples of type, var */
	90	#define _TP_EXPROTO0()
	91	#define _TP_EXPROTO2(a,b) a b
	92	#define _TP_EXPROTO4(a,b,c,d) a b,c d
	93	#define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
	94	#define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
	95	#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
	96	#define _TP_EXPROTO12(a,b,c,d,e,f,g,h,i,j,k,l) a b,c d,e f,g h,i j,k l
	97	#define _TP_EXPROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) a b,c d,e f,g h,i j,k l,m n
	98	#define _TP_EXPROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) a b,c d,e f,g h,i j,k l,m n,o p
	99	#define _TP_EXPROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) a b,c d,e f,g h,i j,k l,m n,o p,q r
	100	#define _TP_EXPROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) a b,c d,e f,g h,i j,k l,m n,o p,q r,s t
	101
	102	#define _TP_EXDATA_PROTO0() void *__tp_data
	103	#define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
	104	#define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
	105	#define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
	106	#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
	107	#define _TP_EXDATA_PROTO10(a,b,c,d,e,f,g,h,i,j) void *__tp_data,a b,c d,e f,g h,i j
	108	#define _TP_EXDATA_PROTO12(a,b,c,d,e,f,g,h,i,j,k,l) void *__tp_data,a b,c d,e f,g h,i j,k l
	109	#define _TP_EXDATA_PROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) void *__tp_data,a b,c d,e f,g h,i j,k l,m n
	110	#define _TP_EXDATA_PROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p
	111	#define _TP_EXDATA_PROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r
	112	#define _TP_EXDATA_PROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r,s t
	113
	114	/* Preprocessor trick to count arguments. Inspired from sdt.h. */
	115	#define _TP_NARGS(...) __TP_NARGS(__VA_ARGS__, 20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
	116	#define __TP_NARGS(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20, N, ...) N
23c8854a MD	117	#define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
	118	#define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
	119	#define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
	120	#define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
b728d87e	121	#define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
23c8854a	122	#define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
b728d87e	123	#define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
23c8854a	124	#define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
b728d87e MD	125	#define _TP_PARAMS(...) __VA_ARGS__
b728d87e MD	126
0f2f7e21 MD	127	#define _DECLARE_TRACEPOINT(_provider, _name, ...) \
	128	extern struct tracepoint __tracepoint_##_provider##___##_name; \
	129	static inline void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
b728d87e MD	130	{ \
	131	struct tracepoint_probe *__tp_probe; \
	132	\
40b2b5a4	133	if (!TP_RCU_LINK_TEST()) \
deb6e540	134	return; \
40b2b5a4	135	tp_rcu_read_lock_bp(); \
0f2f7e21	136	__tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
23c8854a	137	if (caa_unlikely(!__tp_probe)) \
b728d87e MD	138	goto end; \
b728d87e MD	139	do { \
23c8854a MD	140	void *__tp_cb = __tp_probe->func; \
23c8854a MD	141	void *__tp_data = __tp_probe->data; \
b728d87e	142	\
23c8854a MD	143	URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
	144	(_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
	145	} while ((++__tp_probe)->func); \
b728d87e	146	end: \
40b2b5a4	147	tp_rcu_read_unlock_bp(); \
b728d87e	148	} \
0f2f7e21	149	static inline void __tracepoint_register_##_provider##___##_name(char *name, \
23c8854a	150	void func, void data) \
b728d87e	151	{ \
23c8854a	152	__tracepoint_probe_register(name, func, data); \
b728d87e	153	} \
0f2f7e21	154	static inline void __tracepoint_unregister_##_provider##___##_name(char *name, \
23c8854a	155	void func, void data) \
b728d87e	156	{ \
23c8854a	157	__tracepoint_probe_unregister(name, func, data); \
b728d87e MD	158	}
b728d87e MD	159
deb6e540 MD	160	extern int __tracepoint_probe_register(const char name, void func, void *data);
	161	extern int __tracepoint_probe_unregister(const char name, void func, void *data);
	162
51920067 MD	163	/*
	164	* tracepoint dynamic linkage handling (callbacks). Hidden visibility:
	165	* shared across objects in a module/main executable.
	166	*/
	167	struct tracepoint_dlopen {
	168	void *liblttngust_handle;
	169
	170	int (tracepoint_register_lib)(struct tracepoint const *tracepoints_start,
	171	int tracepoints_count);
	172	int (tracepoint_unregister_lib)(struct tracepoint const *tracepoints_start);
	173	#ifndef _LGPL_SOURCE
	174	void (*rcu_read_lock_sym_bp)(void);
	175	void (*rcu_read_unlock_sym_bp)(void);
	176	void (rcu_dereference_sym_bp)(void *p);
	177	#endif
	178	};
	179
	180	extern struct tracepoint_dlopen tracepoint_dlopen;
	181
deb6e540 MD	182	#ifdef TRACEPOINT_DEFINE
deb6e540 MD	183
628e1d81 MD	184	/*
	185	* When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
	186	* unresolved symbol that requires the provider to be linked in. When
	187	* TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
	188	* unresolved symbol that depends on having the provider linked in,
	189	* otherwise the linker complains. This deals with use of static
	190	* libraries, ensuring that the linker does not remove the provider
	191	* object from the executable.
	192	*/
	193	#ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
b4f3bc52	194	#define _TRACEPOINT_UNDEFINED_REF(provider) NULL
628e1d81	195	#else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
b4f3bc52	196	#define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
628e1d81 MD	197	#endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
628e1d81 MD	198
b728d87e MD	199	/*
	200	* Note: to allow PIC code, we need to allow the linker to update the pointers
	201	* in the __tracepoints_ptrs section.
	202	* Therefore, this section is _not_ const (read-only).
	203	*/
b4f3bc52 MD	204	#define _TP_EXTRACT_STRING(...) #__VA_ARGS__
	205
	206	#define _DEFINE_TRACEPOINT(_provider, _name, _args) \
	207	extern int __tracepoint_provider_##_provider; \
	208	static const char __tp_strtab_##_provider##___##_name[] \
b728d87e	209	__attribute__((section("__tracepoints_strings"))) = \
b4f3bc52 MD	210	#_provider ":" #_name; \
b4f3bc52 MD	211	struct tracepoint __tracepoint_##_provider##___##_name \
b728d87e	212	__attribute__((section("__tracepoints"))) = \
b4f3bc52 MD	213	{ \
	214	__tp_strtab_##_provider##___##_name, \
	215	0, \
	216	NULL, \
	217	_TRACEPOINT_UNDEFINED_REF(_provider), \
	218	_TP_EXTRACT_STRING(_args), \
	219	}; \
	220	static struct tracepoint * __tracepoint_ptr_##_provider##___##_name \
b728d87e	221	__attribute__((used, section("__tracepoints_ptrs"))) = \
b4f3bc52	222	&__tracepoint_##_provider##___##_name;
b728d87e	223
b728d87e MD	224	/*
	225	* These weak symbols, the constructor, and destructor take care of
	226	* registering only _one_ instance of the tracepoints per shared-ojbect
	227	* (or for the whole main program).
	228	*/
	229	extern struct tracepoint * const __start___tracepoints_ptrs[]
	230	__attribute__((weak, visibility("hidden")));
	231	extern struct tracepoint * const __stop___tracepoints_ptrs[]
	232	__attribute__((weak, visibility("hidden")));
	233	int __tracepoint_registered
	234	__attribute__((weak, visibility("hidden")));
51920067 MD	235	struct tracepoint_dlopen tracepoint_dlopen
51920067 MD	236	__attribute__((weak, visibility("hidden")));
b728d87e MD	237
	238	static void __attribute__((constructor)) __tracepoints__init(void)
	239	{
	240	if (__tracepoint_registered++)
	241	return;
deb6e540	242
51920067 MD	243	tracepoint_dlopen.liblttngust_handle =
	244	dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW \| RTLD_GLOBAL);
	245	if (!tracepoint_dlopen.liblttngust_handle)
deb6e540	246	return;
51920067	247	tracepoint_dlopen.tracepoint_register_lib =
93ffe366	248	URCU_FORCE_CAST(int ()(struct tracepoint const *, int),
51920067	249	dlsym(tracepoint_dlopen.liblttngust_handle,
93ffe366	250	"tracepoint_register_lib"));
51920067	251	tracepoint_dlopen.tracepoint_unregister_lib =
93ffe366	252	URCU_FORCE_CAST(int ()(struct tracepoint const *),
51920067	253	dlsym(tracepoint_dlopen.liblttngust_handle,
93ffe366	254	"tracepoint_unregister_lib"));
40b2b5a4	255	#ifndef _LGPL_SOURCE
51920067	256	tracepoint_dlopen.rcu_read_lock_sym_bp =
40b2b5a4	257	URCU_FORCE_CAST(void (*)(void),
51920067	258	dlsym(tracepoint_dlopen.liblttngust_handle,
40b2b5a4	259	"tp_rcu_read_lock_bp"));
51920067	260	tracepoint_dlopen.rcu_read_unlock_sym_bp =
40b2b5a4	261	URCU_FORCE_CAST(void (*)(void),
51920067	262	dlsym(tracepoint_dlopen.liblttngust_handle,
40b2b5a4	263	"tp_rcu_read_unlock_bp"));
51920067	264	tracepoint_dlopen.rcu_dereference_sym_bp =
40b2b5a4	265	URCU_FORCE_CAST(void ()(void *p),
51920067	266	dlsym(tracepoint_dlopen.liblttngust_handle,
40b2b5a4 MD	267	"tp_rcu_dereference_sym_bp"));
40b2b5a4 MD	268	#endif
51920067	269	tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs,
b728d87e MD	270	__stop___tracepoints_ptrs -
	271	__start___tracepoints_ptrs);
	272	}
	273
	274	static void __attribute__((destructor)) __tracepoints__destroy(void)
	275	{
deb6e540	276	int ret;
51920067	277
b728d87e MD	278	if (--__tracepoint_registered)
b728d87e MD	279	return;
51920067 MD	280	if (tracepoint_dlopen.tracepoint_unregister_lib)
	281	tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
	282	if (tracepoint_dlopen.liblttngust_handle) {
	283	ret = dlclose(tracepoint_dlopen.liblttngust_handle);
deb6e540	284	assert(!ret);
51920067	285	memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
deb6e540	286	}
b728d87e MD	287	}
b728d87e MD	288
deb6e540 MD	289	#else /* TRACEPOINT_DEFINE */
deb6e540 MD	290
b4f3bc52	291	#define _DEFINE_TRACEPOINT(_provider, _name, _args)
deb6e540 MD	292
	293	#endif /* #else TRACEPOINT_DEFINE */
	294
b728d87e MD	295	#ifdef __cplusplus
	296	}
	297	#endif
	298
	299	#endif /* _LTTNG_TRACEPOINT_H */
	300
	301	/* The following declarations must be outside re-inclusion protection. */
	302
	303	#ifndef TRACEPOINT_EVENT
	304
	305	/*
	306	* How to use the TRACEPOINT_EVENT macro:
	307	*
	308	* An example:
	309	*
	310	* TRACEPOINT_EVENT(someproject_component, event_name,
	311	*
	312	* * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
	313	*
	314	* TP_ARGS(int, arg0, void , arg1, char , string, size_t, strlen,
	315	* long *, arg4, size_t, arg4_len),
	316	*
	317	* * TP_FIELDS describes the event payload layout in the trace *
	318	*
	319	* TP_FIELDS(
	320	* * Integer, printed in base 10 *
	321	* ctf_integer(int, field_a, arg0)
	322	*
	323	* * Integer, printed with 0x base 16 *
	324	* ctf_integer_hex(unsigned long, field_d, arg1)
	325	*
	326	* * Array Sequence, printed as UTF8-encoded array of bytes *
	327	* ctf_array_text(char, field_b, string, FIXED_LEN)
	328	* ctf_sequence_text(char, field_c, string, size_t, strlen)
	329	*
	330	* * String, printed as UTF8-encoded string *
	331	* ctf_string(field_e, string)
	332	*
	333	* * Array sequence of signed integer values *
	334	* ctf_array(long, field_f, arg4, FIXED_LEN4)
	335	* ctf_sequence(long, field_g, arg4, size_t, arg4_len)
	336	* )
	337	* )
	338	*
	339	* More detailed explanation:
	340	*
	341	* The name of the tracepoint is expressed as a tuple with the provider
	342	* and name arguments.
	343	*
	344	* The provider and name should be a proper C99 identifier.
	345	* The "provider" and "name" MUST follow these rules to ensure no
	346	* namespace clash occurs:
	347	*
	348	* For projects (applications and libraries) for which an entity
	349	* specific to the project controls the source code and thus its
	350	* tracepoints (typically with a scope larger than a single company):
	351	*
	352	* either:
	353	* project_component, event
	354	* or:
	355	* project, event
	356	*
	357	* Where "project" is the name of the project,
	358	* "component" is the name of the project component (which may
359	* include several levels of sub-components, e.g.
360	* ...component_subcomponent_...) where the tracepoint is located
361	* (optional),
362	* "event" is the name of the tracepoint event.
363	*
364	* For projects issued from a single company wishing to advertise that
365	* the company controls the source code and thus the tracepoints, the
366	* "com_" prefix should be used:
367	*
368	* either:
369	* com_company_project_component, event
370	* or:
371	* com_company_project, event
372	*
373	* Where "company" is the name of the company,
374	* "project" is the name of the project,
375	* "component" is the name of the project component (which may
376	* include several levels of sub-components, e.g.
377	* ...component_subcomponent_...) where the tracepoint is located
378	* (optional),
379	* "event" is the name of the tracepoint event.
380	*
381	* the provider:event identifier is limited to 127 characters.
382	*/
383
b728d87e	384	#define TRACEPOINT_EVENT(provider, name, args, fields) \
deb6e540	385	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
b4f3bc52	386	_DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
b728d87e MD	387
	388	#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
	389
	390	#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
deb6e540	391	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
b4f3bc52	392	_DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
b728d87e MD	393
	394	#endif /* #ifndef TRACEPOINT_EVENT */
	395
	396	#ifndef TRACEPOINT_LOGLEVEL
	397
	398	/*
75c5ad79	399	* Tracepoint Loglevels
b728d87e MD	400	*
	401	* Typical use of these loglevels:
	402	*
d8de1354	403	* The loglevels go from 0 to 14. Higher numbers imply the most
75c5ad79 MD	404	* verbosity (higher event throughput expected.
75c5ad79 MD	405	*
d8de1354 MD	406	* Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
	407	* semantic. Loglevels 7 through 13 offer more fine-grained selection of
	408	* debug information.
75c5ad79	409	*
d8de1354	410	* TRACE_EMERG 0
75c5ad79 MD	411	* system is unusable
75c5ad79 MD	412	*
d8de1354	413	* TRACE_ALERT 1
75c5ad79 MD	414	* action must be taken immediately
75c5ad79 MD	415	*
d8de1354	416	* TRACE_CRIT 2
75c5ad79 MD	417	* critical conditions
75c5ad79 MD	418	*
d8de1354	419	* TRACE_ERR 3
75c5ad79 MD	420	* error conditions
75c5ad79 MD	421	*
d8de1354	422	* TRACE_WARNING 4
75c5ad79 MD	423	* warning conditions
75c5ad79 MD	424	*
d8de1354	425	* TRACE_NOTICE 5
75c5ad79 MD	426	* normal, but significant, condition
75c5ad79 MD	427	*
d8de1354	428	* TRACE_INFO 6
75c5ad79 MD	429	* informational message
75c5ad79 MD	430	*
d8de1354 MD	431	* TRACE_DEBUG_SYSTEM 7
d8de1354 MD	432	* debug information with system-level scope (set of programs)
75c5ad79	433	*
d8de1354 MD	434	* TRACE_DEBUG_PROGRAM 8
d8de1354 MD	435	* debug information with program-level scope (set of processes)
75c5ad79	436	*
d8de1354 MD	437	* TRACE_DEBUG_PROCESS 9
d8de1354 MD	438	* debug information with process-level scope (set of modules)
75c5ad79	439	*
d8de1354 MD	440	* TRACE_DEBUG_MODULE 10
d8de1354 MD	441	* debug information with module (executable/library) scope (set of units)
75c5ad79	442	*
d8de1354 MD	443	* TRACE_DEBUG_UNIT 11
d8de1354 MD	444	* debug information with compilation unit scope (set of functions)
75c5ad79	445	*
d8de1354 MD	446	* TRACE_DEBUG_FUNCTION 12
d8de1354 MD	447	* debug information with function-level scope
75c5ad79	448	*
d8de1354 MD	449	* TRACE_DEBUG_LINE 13
d8de1354 MD	450	* debug information with line-level scope (TRACEPOINT_EVENT default)
902e1379	451	*
d8de1354	452	* TRACE_DEBUG 14
902e1379	453	* debug-level message (trace_printf default)
75c5ad79 MD	454	*
	455	* Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
	456	* should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
853cda88 MD	457	* tracepoint name. The first field is the provider name, the second
	458	* field is the name of the tracepoint, the third field is the loglevel
	459	* name.
b728d87e MD	460	*
	461	* TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
	462	* < loglevel_name >)
	463	*
75c5ad79 MD	464	* The TRACEPOINT_PROVIDER must be already declared before declaring a
75c5ad79 MD	465	* TRACEPOINT_LOGLEVEL.
b728d87e MD	466	*/
b728d87e MD	467
882a56d7	468	enum {
d8de1354 MD	469	TRACE_EMERG = 0,
	470	TRACE_ALERT = 1,
	471	TRACE_CRIT = 2,
	472	TRACE_ERR = 3,
	473	TRACE_WARNING = 4,
	474	TRACE_NOTICE = 5,
	475	TRACE_INFO = 6,
	476	TRACE_DEBUG_SYSTEM = 7,
	477	TRACE_DEBUG_PROGRAM = 8,
	478	TRACE_DEBUG_PROCESS = 9,
	479	TRACE_DEBUG_MODULE = 10,
	480	TRACE_DEBUG_UNIT = 11,
	481	TRACE_DEBUG_FUNCTION = 12,
	482	TRACE_DEBUG_LINE = 13,
	483	TRACE_DEBUG = 14,
882a56d7 MD	484	};
882a56d7 MD	485
05ceaafd	486	#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
b728d87e MD	487
b728d87e MD	488	#endif /* #ifndef TRACEPOINT_LOGLEVEL */