[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,					\
		__tracepoint_##_provider##___##_name.signature);			\
}											\
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,
		const char *signature);
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	{ \
67e5f391 MD	152	__tracepoint_probe_register(name, func, data, \
67e5f391 MD	153	__tracepoint_##_provider##___##_name.signature); \
b728d87e	154	} \
0f2f7e21	155	static inline void __tracepoint_unregister_##_provider##___##_name(char *name, \
23c8854a	156	void func, void data) \
b728d87e	157	{ \
23c8854a	158	__tracepoint_probe_unregister(name, func, data); \
b728d87e MD	159	}
b728d87e MD	160
67e5f391 MD	161	extern int __tracepoint_probe_register(const char name, void func, void *data,
67e5f391 MD	162	const char *signature);
deb6e540 MD	163	extern int __tracepoint_probe_unregister(const char name, void func, void *data);
deb6e540 MD	164
51920067 MD	165	/*
	166	* tracepoint dynamic linkage handling (callbacks). Hidden visibility:
	167	* shared across objects in a module/main executable.
	168	*/
	169	struct tracepoint_dlopen {
	170	void *liblttngust_handle;
	171
	172	int (tracepoint_register_lib)(struct tracepoint const *tracepoints_start,
	173	int tracepoints_count);
	174	int (tracepoint_unregister_lib)(struct tracepoint const *tracepoints_start);
	175	#ifndef _LGPL_SOURCE
	176	void (*rcu_read_lock_sym_bp)(void);
	177	void (*rcu_read_unlock_sym_bp)(void);
	178	void (rcu_dereference_sym_bp)(void *p);
	179	#endif
	180	};
	181
	182	extern struct tracepoint_dlopen tracepoint_dlopen;
	183
deb6e540 MD	184	#ifdef TRACEPOINT_DEFINE
deb6e540 MD	185
628e1d81 MD	186	/*
	187	* When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
	188	* unresolved symbol that requires the provider to be linked in. When
	189	* TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
	190	* unresolved symbol that depends on having the provider linked in,
	191	* otherwise the linker complains. This deals with use of static
	192	* libraries, ensuring that the linker does not remove the provider
	193	* object from the executable.
	194	*/
	195	#ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
b4f3bc52	196	#define _TRACEPOINT_UNDEFINED_REF(provider) NULL
628e1d81	197	#else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
b4f3bc52	198	#define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
628e1d81 MD	199	#endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
628e1d81 MD	200
b728d87e MD	201	/*
	202	* Note: to allow PIC code, we need to allow the linker to update the pointers
	203	* in the __tracepoints_ptrs section.
	204	* Therefore, this section is _not_ const (read-only).
	205	*/
b4f3bc52 MD	206	#define _TP_EXTRACT_STRING(...) #__VA_ARGS__
	207
	208	#define _DEFINE_TRACEPOINT(_provider, _name, _args) \
	209	extern int __tracepoint_provider_##_provider; \
	210	static const char __tp_strtab_##_provider##___##_name[] \
b728d87e	211	__attribute__((section("__tracepoints_strings"))) = \
b4f3bc52 MD	212	#_provider ":" #_name; \
b4f3bc52 MD	213	struct tracepoint __tracepoint_##_provider##___##_name \
b728d87e	214	__attribute__((section("__tracepoints"))) = \
b4f3bc52 MD	215	{ \
	216	__tp_strtab_##_provider##___##_name, \
	217	0, \
	218	NULL, \
	219	_TRACEPOINT_UNDEFINED_REF(_provider), \
	220	_TP_EXTRACT_STRING(_args), \
	221	}; \
	222	static struct tracepoint * __tracepoint_ptr_##_provider##___##_name \
b728d87e	223	__attribute__((used, section("__tracepoints_ptrs"))) = \
b4f3bc52	224	&__tracepoint_##_provider##___##_name;
b728d87e	225
b728d87e MD	226	/*
	227	* These weak symbols, the constructor, and destructor take care of
	228	* registering only _one_ instance of the tracepoints per shared-ojbect
	229	* (or for the whole main program).
	230	*/
	231	extern struct tracepoint * const __start___tracepoints_ptrs[]
	232	__attribute__((weak, visibility("hidden")));
	233	extern struct tracepoint * const __stop___tracepoints_ptrs[]
	234	__attribute__((weak, visibility("hidden")));
	235	int __tracepoint_registered
	236	__attribute__((weak, visibility("hidden")));
51920067 MD	237	struct tracepoint_dlopen tracepoint_dlopen
51920067 MD	238	__attribute__((weak, visibility("hidden")));
b728d87e MD	239
	240	static void __attribute__((constructor)) __tracepoints__init(void)
	241	{
	242	if (__tracepoint_registered++)
	243	return;
deb6e540	244
51920067 MD	245	tracepoint_dlopen.liblttngust_handle =
	246	dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW \| RTLD_GLOBAL);
	247	if (!tracepoint_dlopen.liblttngust_handle)
deb6e540	248	return;
51920067	249	tracepoint_dlopen.tracepoint_register_lib =
93ffe366	250	URCU_FORCE_CAST(int ()(struct tracepoint const *, int),
51920067	251	dlsym(tracepoint_dlopen.liblttngust_handle,
93ffe366	252	"tracepoint_register_lib"));
51920067	253	tracepoint_dlopen.tracepoint_unregister_lib =
93ffe366	254	URCU_FORCE_CAST(int ()(struct tracepoint const *),
51920067	255	dlsym(tracepoint_dlopen.liblttngust_handle,
93ffe366	256	"tracepoint_unregister_lib"));
40b2b5a4	257	#ifndef _LGPL_SOURCE
51920067	258	tracepoint_dlopen.rcu_read_lock_sym_bp =
40b2b5a4	259	URCU_FORCE_CAST(void (*)(void),
51920067	260	dlsym(tracepoint_dlopen.liblttngust_handle,
40b2b5a4	261	"tp_rcu_read_lock_bp"));
51920067	262	tracepoint_dlopen.rcu_read_unlock_sym_bp =
40b2b5a4	263	URCU_FORCE_CAST(void (*)(void),
51920067	264	dlsym(tracepoint_dlopen.liblttngust_handle,
40b2b5a4	265	"tp_rcu_read_unlock_bp"));
51920067	266	tracepoint_dlopen.rcu_dereference_sym_bp =
40b2b5a4	267	URCU_FORCE_CAST(void ()(void *p),
51920067	268	dlsym(tracepoint_dlopen.liblttngust_handle,
40b2b5a4 MD	269	"tp_rcu_dereference_sym_bp"));
40b2b5a4 MD	270	#endif
51920067	271	tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs,
b728d87e MD	272	__stop___tracepoints_ptrs -
	273	__start___tracepoints_ptrs);
	274	}
	275
	276	static void __attribute__((destructor)) __tracepoints__destroy(void)
	277	{
deb6e540	278	int ret;
51920067	279
b728d87e MD	280	if (--__tracepoint_registered)
b728d87e MD	281	return;
51920067 MD	282	if (tracepoint_dlopen.tracepoint_unregister_lib)
	283	tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
	284	if (tracepoint_dlopen.liblttngust_handle) {
	285	ret = dlclose(tracepoint_dlopen.liblttngust_handle);
deb6e540	286	assert(!ret);
51920067	287	memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
deb6e540	288	}
b728d87e MD	289	}
b728d87e MD	290
deb6e540 MD	291	#else /* TRACEPOINT_DEFINE */
deb6e540 MD	292
b4f3bc52	293	#define _DEFINE_TRACEPOINT(_provider, _name, _args)
deb6e540 MD	294
	295	#endif /* #else TRACEPOINT_DEFINE */
	296
b728d87e MD	297	#ifdef __cplusplus
	298	}
	299	#endif
	300
	301	#endif /* _LTTNG_TRACEPOINT_H */
	302
	303	/* The following declarations must be outside re-inclusion protection. */
	304
	305	#ifndef TRACEPOINT_EVENT
	306
	307	/*
	308	* How to use the TRACEPOINT_EVENT macro:
	309	*
	310	* An example:
	311	*
	312	* TRACEPOINT_EVENT(someproject_component, event_name,
	313	*
	314	* * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
	315	*
	316	* TP_ARGS(int, arg0, void , arg1, char , string, size_t, strlen,
	317	* long *, arg4, size_t, arg4_len),
	318	*
	319	* * TP_FIELDS describes the event payload layout in the trace *
	320	*
	321	* TP_FIELDS(
	322	* * Integer, printed in base 10 *
	323	* ctf_integer(int, field_a, arg0)
	324	*
	325	* * Integer, printed with 0x base 16 *
	326	* ctf_integer_hex(unsigned long, field_d, arg1)
	327	*
	328	* * Array Sequence, printed as UTF8-encoded array of bytes *
	329	* ctf_array_text(char, field_b, string, FIXED_LEN)
	330	* ctf_sequence_text(char, field_c, string, size_t, strlen)
	331	*
	332	* * String, printed as UTF8-encoded string *
	333	* ctf_string(field_e, string)
	334	*
	335	* * Array sequence of signed integer values *
	336	* ctf_array(long, field_f, arg4, FIXED_LEN4)
	337	* ctf_sequence(long, field_g, arg4, size_t, arg4_len)
	338	* )
	339	* )
	340	*
	341	* More detailed explanation:
	342	*
	343	* The name of the tracepoint is expressed as a tuple with the provider
	344	* and name arguments.
	345	*
	346	* The provider and name should be a proper C99 identifier.
	347	* The "provider" and "name" MUST follow these rules to ensure no
	348	* namespace clash occurs:
	349	*
	350	* For projects (applications and libraries) for which an entity
	351	* specific to the project controls the source code and thus its
	352	* tracepoints (typically with a scope larger than a single company):
	353	*
	354	* either:
	355	* project_component, event
	356	* or:
	357	* project, event
	358	*
	359	* Where "project" is the name of the project,
	360	* "component" is the name of the project component (which may
361	* include several levels of sub-components, e.g.
362	* ...component_subcomponent_...) where the tracepoint is located
363	* (optional),
364	* "event" is the name of the tracepoint event.
365	*
366	* For projects issued from a single company wishing to advertise that
367	* the company controls the source code and thus the tracepoints, the
368	* "com_" prefix should be used:
369	*
370	* either:
371	* com_company_project_component, event
372	* or:
373	* com_company_project, event
374	*
375	* Where "company" is the name of the company,
376	* "project" is the name of the project,
377	* "component" is the name of the project component (which may
378	* include several levels of sub-components, e.g.
379	* ...component_subcomponent_...) where the tracepoint is located
380	* (optional),
381	* "event" is the name of the tracepoint event.
382	*
383	* the provider:event identifier is limited to 127 characters.
384	*/
385
b728d87e	386	#define TRACEPOINT_EVENT(provider, name, args, fields) \
deb6e540	387	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
b4f3bc52	388	_DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
b728d87e MD	389
	390	#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
	391
	392	#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
deb6e540	393	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
b4f3bc52	394	_DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
b728d87e MD	395
	396	#endif /* #ifndef TRACEPOINT_EVENT */
	397
	398	#ifndef TRACEPOINT_LOGLEVEL
	399
	400	/*
75c5ad79	401	* Tracepoint Loglevels
b728d87e MD	402	*
	403	* Typical use of these loglevels:
	404	*
d8de1354	405	* The loglevels go from 0 to 14. Higher numbers imply the most
75c5ad79 MD	406	* verbosity (higher event throughput expected.
75c5ad79 MD	407	*
d8de1354 MD	408	* Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
	409	* semantic. Loglevels 7 through 13 offer more fine-grained selection of
	410	* debug information.
75c5ad79	411	*
d8de1354	412	* TRACE_EMERG 0
75c5ad79 MD	413	* system is unusable
75c5ad79 MD	414	*
d8de1354	415	* TRACE_ALERT 1
75c5ad79 MD	416	* action must be taken immediately
75c5ad79 MD	417	*
d8de1354	418	* TRACE_CRIT 2
75c5ad79 MD	419	* critical conditions
75c5ad79 MD	420	*
d8de1354	421	* TRACE_ERR 3
75c5ad79 MD	422	* error conditions
75c5ad79 MD	423	*
d8de1354	424	* TRACE_WARNING 4
75c5ad79 MD	425	* warning conditions
75c5ad79 MD	426	*
d8de1354	427	* TRACE_NOTICE 5
75c5ad79 MD	428	* normal, but significant, condition
75c5ad79 MD	429	*
d8de1354	430	* TRACE_INFO 6
75c5ad79 MD	431	* informational message
75c5ad79 MD	432	*
d8de1354 MD	433	* TRACE_DEBUG_SYSTEM 7
d8de1354 MD	434	* debug information with system-level scope (set of programs)
75c5ad79	435	*
d8de1354 MD	436	* TRACE_DEBUG_PROGRAM 8
d8de1354 MD	437	* debug information with program-level scope (set of processes)
75c5ad79	438	*
d8de1354 MD	439	* TRACE_DEBUG_PROCESS 9
d8de1354 MD	440	* debug information with process-level scope (set of modules)
75c5ad79	441	*
d8de1354 MD	442	* TRACE_DEBUG_MODULE 10
d8de1354 MD	443	* debug information with module (executable/library) scope (set of units)
75c5ad79	444	*
d8de1354 MD	445	* TRACE_DEBUG_UNIT 11
d8de1354 MD	446	* debug information with compilation unit scope (set of functions)
75c5ad79	447	*
d8de1354 MD	448	* TRACE_DEBUG_FUNCTION 12
d8de1354 MD	449	* debug information with function-level scope
75c5ad79	450	*
d8de1354 MD	451	* TRACE_DEBUG_LINE 13
d8de1354 MD	452	* debug information with line-level scope (TRACEPOINT_EVENT default)
902e1379	453	*
d8de1354	454	* TRACE_DEBUG 14
902e1379	455	* debug-level message (trace_printf default)
75c5ad79 MD	456	*
	457	* Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
	458	* should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
853cda88 MD	459	* tracepoint name. The first field is the provider name, the second
	460	* field is the name of the tracepoint, the third field is the loglevel
	461	* name.
b728d87e MD	462	*
	463	* TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
	464	* < loglevel_name >)
	465	*
75c5ad79 MD	466	* The TRACEPOINT_PROVIDER must be already declared before declaring a
75c5ad79 MD	467	* TRACEPOINT_LOGLEVEL.
b728d87e MD	468	*/
b728d87e MD	469
882a56d7	470	enum {
d8de1354 MD	471	TRACE_EMERG = 0,
	472	TRACE_ALERT = 1,
	473	TRACE_CRIT = 2,
	474	TRACE_ERR = 3,
	475	TRACE_WARNING = 4,
	476	TRACE_NOTICE = 5,
	477	TRACE_INFO = 6,
	478	TRACE_DEBUG_SYSTEM = 7,
	479	TRACE_DEBUG_PROGRAM = 8,
	480	TRACE_DEBUG_PROCESS = 9,
	481	TRACE_DEBUG_MODULE = 10,
	482	TRACE_DEBUG_UNIT = 11,
	483	TRACE_DEBUG_FUNCTION = 12,
	484	TRACE_DEBUG_LINE = 13,
	485	TRACE_DEBUG = 14,
882a56d7 MD	486	};
882a56d7 MD	487
05ceaafd	488	#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
b728d87e MD	489
b728d87e MD	490	#endif /* #ifndef TRACEPOINT_LOGLEVEL */