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#ifndef _LTTNG_TRACEPOINT_H
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#define _LTTNG_TRACEPOINT_H
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* Copyright 2011-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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#include <lttng/tracepoint-types.h>
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#include <lttng/tracepoint-rcu.h>
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#include <urcu/compiler.h>
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#include <dlfcn.h> /* for dlopen */
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#include <string.h> /* for memset */
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#include <lttng/ust-config.h> /* for sdt */
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#ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
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#define SDT_USE_VARIADIC
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#define STAP_PROBEV(...)
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#define tracepoint(provider, name, ...) \
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STAP_PROBEV(provider, name, ## __VA_ARGS__); \
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if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
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__tracepoint_cb_##provider##___##name(__VA_ARGS__); \
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#define TP_ARGS(...) __VA_ARGS__
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* TP_ARGS takes tuples of type, argument separated by a comma.
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* It can take up to 10 tuples (which means that less than 10 tuples is
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* Each tuple is also separated by a comma.
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#define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
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#define _TP_COMBINE_TOKENS(_tokena, _tokenb) \
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__TP_COMBINE_TOKENS(_tokena, _tokenb)
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#define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
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_tokena##_tokenb##_tokenc
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#define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
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__TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
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#define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
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_tokena##_tokenb##_tokenc##_tokend
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#define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
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__TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
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* _TP_EXVAR* extract the var names.
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* _TP_EXVAR1 and _TP_EXDATA_VAR1 are needed for -std=c99.
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#define _TP_EXVAR2(a,b) b
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#define _TP_EXVAR4(a,b,c,d) b,d
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#define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
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#define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
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#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
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#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
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#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
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#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
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#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
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#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
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#define _TP_EXDATA_VAR0() __tp_data
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#define _TP_EXDATA_VAR1(a) __tp_data
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#define _TP_EXDATA_VAR2(a,b) __tp_data,b
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#define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
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#define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
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#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
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#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
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#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
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#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
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#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
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#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
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#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
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* _TP_EXPROTO* extract tuples of type, var.
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* _TP_EXPROTO1 and _TP_EXDATA_PROTO1 are needed for -std=c99.
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#define _TP_EXPROTO0() void
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#define _TP_EXPROTO1(a) void
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#define _TP_EXPROTO2(a,b) a b
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#define _TP_EXPROTO4(a,b,c,d) a b,c d
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#define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
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#define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
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#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
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#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
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#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
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#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
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#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
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#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
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#define _TP_EXDATA_PROTO0() void *__tp_data
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#define _TP_EXDATA_PROTO1(a) void *__tp_data
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#define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
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#define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
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#define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
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#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
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#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
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#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
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#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
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#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
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#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
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#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
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/* Preprocessor trick to count arguments. Inspired from sdt.h. */
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#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)
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#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
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#define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
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#define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
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#define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
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#define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
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#define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
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#define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
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#define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
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#define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
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#define _TP_PARAMS(...) __VA_ARGS__
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#define _DECLARE_TRACEPOINT(_provider, _name, ...) \
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extern struct tracepoint __tracepoint_##_provider##___##_name; \
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static inline void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
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struct tracepoint_probe *__tp_probe; \
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if (!TP_RCU_LINK_TEST()) \
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tp_rcu_read_lock_bp(); \
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__tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
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if (caa_unlikely(!__tp_probe)) \
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void *__tp_cb = __tp_probe->func; \
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void *__tp_data = __tp_probe->data; \
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URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
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(_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
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} while ((++__tp_probe)->func); \
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tp_rcu_read_unlock_bp(); \
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static inline void __tracepoint_register_##_provider##___##_name(char *name, \
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void *func, void *data) \
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__tracepoint_probe_register(name, func, data, \
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__tracepoint_##_provider##___##_name.signature); \
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static inline void __tracepoint_unregister_##_provider##___##_name(char *name, \
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void *func, void *data) \
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__tracepoint_probe_unregister(name, func, data); \
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extern int __tracepoint_probe_register(const char *name, void *func, void *data,
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const char *signature);
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extern int __tracepoint_probe_unregister(const char *name, void *func, void *data);
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* tracepoint dynamic linkage handling (callbacks). Hidden visibility:
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* shared across objects in a module/main executable.
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struct tracepoint_dlopen {
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void *liblttngust_handle;
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int (*tracepoint_register_lib)(struct tracepoint * const *tracepoints_start,
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int tracepoints_count);
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int (*tracepoint_unregister_lib)(struct tracepoint * const *tracepoints_start);
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void (*rcu_read_lock_sym_bp)(void);
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void (*rcu_read_unlock_sym_bp)(void);
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void *(*rcu_dereference_sym_bp)(void *p);
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extern struct tracepoint_dlopen tracepoint_dlopen;
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#ifdef TRACEPOINT_DEFINE
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* When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
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* unresolved symbol that requires the provider to be linked in. When
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* TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
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* unresolved symbol that depends on having the provider linked in,
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* otherwise the linker complains. This deals with use of static
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* libraries, ensuring that the linker does not remove the provider
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* object from the executable.
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#ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
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#define _TRACEPOINT_UNDEFINED_REF(provider) NULL
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#else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
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#define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
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#endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
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* Note: to allow PIC code, we need to allow the linker to update the pointers
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* in the __tracepoints_ptrs section.
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* Therefore, this section is _not_ const (read-only).
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#define _TP_EXTRACT_STRING(...) #__VA_ARGS__
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#define _DEFINE_TRACEPOINT(_provider, _name, _args) \
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extern int __tracepoint_provider_##_provider; \
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static const char __tp_strtab_##_provider##___##_name[] \
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__attribute__((section("__tracepoints_strings"))) = \
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#_provider ":" #_name; \
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struct tracepoint __tracepoint_##_provider##___##_name \
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__attribute__((section("__tracepoints"))) = \
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__tp_strtab_##_provider##___##_name, \
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_TRACEPOINT_UNDEFINED_REF(_provider), \
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_TP_EXTRACT_STRING(_args), \
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static struct tracepoint * __tracepoint_ptr_##_provider##___##_name \
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__attribute__((used, section("__tracepoints_ptrs"))) = \
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&__tracepoint_##_provider##___##_name;
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* These weak symbols, the constructor, and destructor take care of
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* registering only _one_ instance of the tracepoints per shared-ojbect
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* (or for the whole main program).
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extern struct tracepoint * const __start___tracepoints_ptrs[]
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__attribute__((weak, visibility("hidden")));
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extern struct tracepoint * const __stop___tracepoints_ptrs[]
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__attribute__((weak, visibility("hidden")));
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int __tracepoint_registered
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__attribute__((weak, visibility("hidden")));
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struct tracepoint_dlopen tracepoint_dlopen
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__attribute__((weak, visibility("hidden")));
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static void __attribute__((constructor)) __tracepoints__init(void)
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if (__tracepoint_registered++)
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tracepoint_dlopen.liblttngust_handle =
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dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
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if (!tracepoint_dlopen.liblttngust_handle)
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tracepoint_dlopen.tracepoint_register_lib =
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URCU_FORCE_CAST(int (*)(struct tracepoint * const *, int),
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dlsym(tracepoint_dlopen.liblttngust_handle,
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"tracepoint_register_lib"));
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tracepoint_dlopen.tracepoint_unregister_lib =
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URCU_FORCE_CAST(int (*)(struct tracepoint * const *),
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dlsym(tracepoint_dlopen.liblttngust_handle,
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"tracepoint_unregister_lib"));
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tracepoint_dlopen.rcu_read_lock_sym_bp =
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URCU_FORCE_CAST(void (*)(void),
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dlsym(tracepoint_dlopen.liblttngust_handle,
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"tp_rcu_read_lock_bp"));
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tracepoint_dlopen.rcu_read_unlock_sym_bp =
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URCU_FORCE_CAST(void (*)(void),
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dlsym(tracepoint_dlopen.liblttngust_handle,
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"tp_rcu_read_unlock_bp"));
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tracepoint_dlopen.rcu_dereference_sym_bp =
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URCU_FORCE_CAST(void *(*)(void *p),
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dlsym(tracepoint_dlopen.liblttngust_handle,
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"tp_rcu_dereference_sym_bp"));
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tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs,
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__stop___tracepoints_ptrs -
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__start___tracepoints_ptrs);
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static void __attribute__((destructor)) __tracepoints__destroy(void)
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if (--__tracepoint_registered)
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if (tracepoint_dlopen.tracepoint_unregister_lib)
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tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
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if (tracepoint_dlopen.liblttngust_handle) {
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ret = dlclose(tracepoint_dlopen.liblttngust_handle);
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memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
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#else /* TRACEPOINT_DEFINE */
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#define _DEFINE_TRACEPOINT(_provider, _name, _args)
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#endif /* #else TRACEPOINT_DEFINE */
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#endif /* _LTTNG_TRACEPOINT_H */
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/* The following declarations must be outside re-inclusion protection. */
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#ifndef TRACEPOINT_EVENT
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* How to use the TRACEPOINT_EVENT macro:
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* TRACEPOINT_EVENT(someproject_component, event_name,
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* * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
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* TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
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* long *, arg4, size_t, arg4_len),
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* * TP_FIELDS describes the event payload layout in the trace *
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* * Integer, printed in base 10 *
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* ctf_integer(int, field_a, arg0)
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* * Integer, printed with 0x base 16 *
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* ctf_integer_hex(unsigned long, field_d, arg1)
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* * Array Sequence, printed as UTF8-encoded array of bytes *
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* ctf_array_text(char, field_b, string, FIXED_LEN)
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* ctf_sequence_text(char, field_c, string, size_t, strlen)
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* * String, printed as UTF8-encoded string *
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* ctf_string(field_e, string)
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* * Array sequence of signed integer values *
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* ctf_array(long, field_f, arg4, FIXED_LEN4)
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* ctf_sequence(long, field_g, arg4, size_t, arg4_len)
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* More detailed explanation:
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* The name of the tracepoint is expressed as a tuple with the provider
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* and name arguments.
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* The provider and name should be a proper C99 identifier.
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* The "provider" and "name" MUST follow these rules to ensure no
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* namespace clash occurs:
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* For projects (applications and libraries) for which an entity
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* specific to the project controls the source code and thus its
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* tracepoints (typically with a scope larger than a single company):
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* project_component, event
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* Where "project" is the name of the project,
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* "component" is the name of the project component (which may
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* include several levels of sub-components, e.g.
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* ...component_subcomponent_...) where the tracepoint is located
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* "event" is the name of the tracepoint event.
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* For projects issued from a single company wishing to advertise that
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* the company controls the source code and thus the tracepoints, the
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* "com_" prefix should be used:
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* com_company_project_component, event
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* com_company_project, event
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* Where "company" is the name of the company,
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* "project" is the name of the project,
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* "component" is the name of the project component (which may
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* include several levels of sub-components, e.g.
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* ...component_subcomponent_...) where the tracepoint is located
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* "event" is the name of the tracepoint event.
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* the provider:event identifier is limited to 127 characters.
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#define TRACEPOINT_EVENT(provider, name, args, fields) \
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_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
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_DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
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#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
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#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
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_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
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_DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
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#endif /* #ifndef TRACEPOINT_EVENT */
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#ifndef TRACEPOINT_LOGLEVEL
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* Tracepoint Loglevels
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* Typical use of these loglevels:
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* The loglevels go from 0 to 14. Higher numbers imply the most
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* verbosity (higher event throughput expected.
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* Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
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* semantic. Loglevels 7 through 13 offer more fine-grained selection of
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* action must be taken immediately
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* critical conditions
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* normal, but significant, condition
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* informational message
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* TRACE_DEBUG_SYSTEM 7
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* debug information with system-level scope (set of programs)
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* TRACE_DEBUG_PROGRAM 8
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* debug information with program-level scope (set of processes)
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* TRACE_DEBUG_PROCESS 9
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* debug information with process-level scope (set of modules)
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* TRACE_DEBUG_MODULE 10
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* debug information with module (executable/library) scope (set of units)
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* TRACE_DEBUG_UNIT 11
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* debug information with compilation unit scope (set of functions)
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* TRACE_DEBUG_FUNCTION 12
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* debug information with function-level scope
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* TRACE_DEBUG_LINE 13
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* debug information with line-level scope (TRACEPOINT_EVENT default)
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* debug-level message (trace_printf default)
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* Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
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* should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
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* tracepoint name. The first field is the provider name, the second
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* field is the name of the tracepoint, the third field is the loglevel
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* TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
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* The TRACEPOINT_PROVIDER must be already declared before declaring a
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* TRACEPOINT_LOGLEVEL.
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TRACE_DEBUG_SYSTEM = 7,
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TRACE_DEBUG_PROGRAM = 8,
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TRACE_DEBUG_PROCESS = 9,
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TRACE_DEBUG_MODULE = 10,
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TRACE_DEBUG_UNIT = 11,
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TRACE_DEBUG_FUNCTION = 12,
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TRACE_DEBUG_LINE = 13,
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#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
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#endif /* #ifndef TRACEPOINT_LOGLEVEL */
added
removed
include/lttng/tracepoint.h
