1 #ifndef _LTTNG_TRACEPOINT_H
2 #define _LTTNG_TRACEPOINT_H
5 * Copyright 2011-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
18 #include <lttng/tracepoint-types.h>
19 #include <lttng/tracepoint-rcu.h>
20 #include <urcu/compiler.h>
21 #include <dlfcn.h> /* for dlopen */
22 #include <string.h> /* for memset */
24 #include <lttng/ust-config.h> /* for sdt */
25 #include <lttng/ust-compiler.h>
27 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
28 #define SDT_USE_VARIADIC
31 #define STAP_PROBEV(...)
38 #define tracepoint(provider, name, ...) \
40 STAP_PROBEV(provider, name, ## __VA_ARGS__); \
41 if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
42 __tracepoint_cb_##provider##___##name(__VA_ARGS__); \
45 #define TP_ARGS(...) __VA_ARGS__
48 * TP_ARGS takes tuples of type, argument separated by a comma.
49 * It can take up to 10 tuples (which means that less than 10 tuples is
51 * Each tuple is also separated by a comma.
53 #define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
55 #define _TP_COMBINE_TOKENS(_tokena, _tokenb) \
56 __TP_COMBINE_TOKENS(_tokena, _tokenb)
57 #define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
58 _tokena##_tokenb##_tokenc
59 #define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
60 __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
61 #define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
62 _tokena##_tokenb##_tokenc##_tokend
63 #define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
64 __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
67 * _TP_EXVAR* extract the var names.
68 * _TP_EXVAR1 and _TP_EXDATA_VAR1 are needed for -std=c99.
72 #define _TP_EXVAR2(a,b) b
73 #define _TP_EXVAR4(a,b,c,d) b,d
74 #define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
75 #define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
76 #define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
77 #define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
78 #define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
79 #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
80 #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
81 #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
83 #define _TP_EXDATA_VAR0() __tp_data
84 #define _TP_EXDATA_VAR1(a) __tp_data
85 #define _TP_EXDATA_VAR2(a,b) __tp_data,b
86 #define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
87 #define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
88 #define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
89 #define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
90 #define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
91 #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
92 #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
93 #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
94 #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
97 * _TP_EXPROTO* extract tuples of type, var.
98 * _TP_EXPROTO1 and _TP_EXDATA_PROTO1 are needed for -std=c99.
100 #define _TP_EXPROTO0() void
101 #define _TP_EXPROTO1(a) void
102 #define _TP_EXPROTO2(a,b) a b
103 #define _TP_EXPROTO4(a,b,c,d) a b,c d
104 #define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
105 #define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
106 #define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
107 #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
108 #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
109 #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
110 #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
111 #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
113 #define _TP_EXDATA_PROTO0() void *__tp_data
114 #define _TP_EXDATA_PROTO1(a) void *__tp_data
115 #define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
116 #define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
117 #define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
118 #define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
119 #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
120 #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
121 #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
122 #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
123 #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
124 #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
126 /* Preprocessor trick to count arguments. Inspired from sdt.h. */
127 #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)
128 #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
129 #define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
130 #define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
131 #define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
132 #define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
133 #define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
134 #define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
135 #define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
136 #define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
137 #define _TP_PARAMS(...) __VA_ARGS__
139 #define _DECLARE_TRACEPOINT(_provider, _name, ...) \
140 extern struct tracepoint __tracepoint_##_provider##___##_name; \
141 static inline lttng_ust_notrace \
142 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)); \
144 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
146 struct tracepoint_probe *__tp_probe; \
148 if (!TP_RCU_LINK_TEST()) \
150 tp_rcu_read_lock_bp(); \
151 __tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
152 if (caa_unlikely(!__tp_probe)) \
155 void (*__tp_cb)(void) = __tp_probe->func; \
156 void *__tp_data = __tp_probe->data; \
158 URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
159 (_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
160 } while ((++__tp_probe)->func); \
162 tp_rcu_read_unlock_bp(); \
164 static inline lttng_ust_notrace \
165 void __tracepoint_register_##_provider##___##_name(char *name, \
166 void (*func)(void), void *data); \
168 void __tracepoint_register_##_provider##___##_name(char *name, \
169 void (*func)(void), void *data) \
171 __tracepoint_probe_register(name, func, data, \
172 __tracepoint_##_provider##___##_name.signature); \
174 static inline lttng_ust_notrace \
175 void __tracepoint_unregister_##_provider##___##_name(char *name, \
176 void (*func)(void), void *data); \
178 void __tracepoint_unregister_##_provider##___##_name(char *name, \
179 void (*func)(void), void *data) \
181 __tracepoint_probe_unregister(name, func, data); \
184 extern int __tracepoint_probe_register(const char *name
, void (*func
)(void),
185 void *data
, const char *signature
);
186 extern int __tracepoint_probe_unregister(const char *name
, void (*func
)(void),
190 * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
191 * shared across objects in a module/main executable.
193 struct tracepoint_dlopen
{
194 void *liblttngust_handle
;
196 int (*tracepoint_register_lib
)(struct tracepoint
* const *tracepoints_start
,
197 int tracepoints_count
);
198 int (*tracepoint_unregister_lib
)(struct tracepoint
* const *tracepoints_start
);
200 void (*rcu_read_lock_sym_bp
)(void);
201 void (*rcu_read_unlock_sym_bp
)(void);
202 void *(*rcu_dereference_sym_bp
)(void *p
);
206 extern struct tracepoint_dlopen tracepoint_dlopen
;
208 #ifdef TRACEPOINT_DEFINE
211 * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
212 * unresolved symbol that requires the provider to be linked in. When
213 * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
214 * unresolved symbol that depends on having the provider linked in,
215 * otherwise the linker complains. This deals with use of static
216 * libraries, ensuring that the linker does not remove the provider
217 * object from the executable.
219 #ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
220 #define _TRACEPOINT_UNDEFINED_REF(provider) NULL
221 #else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
222 #define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
223 #endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
226 * Note: to allow PIC code, we need to allow the linker to update the pointers
227 * in the __tracepoints_ptrs section.
228 * Therefore, this section is _not_ const (read-only).
230 #define _TP_EXTRACT_STRING(...) #__VA_ARGS__
232 #define _DEFINE_TRACEPOINT(_provider, _name, _args) \
233 extern int __tracepoint_provider_##_provider; \
234 static const char __tp_strtab_##_provider##___##_name[] \
235 __attribute__((section("__tracepoints_strings"))) = \
236 #_provider ":" #_name; \
237 struct tracepoint __tracepoint_##_provider##___##_name \
238 __attribute__((section("__tracepoints"))) = \
240 __tp_strtab_##_provider##___##_name, \
243 _TRACEPOINT_UNDEFINED_REF(_provider), \
244 _TP_EXTRACT_STRING(_args), \
246 static struct tracepoint * __tracepoint_ptr_##_provider##___##_name \
247 __attribute__((used, section("__tracepoints_ptrs"))) = \
248 &__tracepoint_##_provider##___##_name;
251 * These weak symbols, the constructor, and destructor take care of
252 * registering only _one_ instance of the tracepoints per shared-ojbect
253 * (or for the whole main program).
255 extern struct tracepoint
* const __start___tracepoints_ptrs
[]
256 __attribute__((weak
, visibility("hidden")));
257 extern struct tracepoint
* const __stop___tracepoints_ptrs
[]
258 __attribute__((weak
, visibility("hidden")));
259 int __tracepoint_registered
260 __attribute__((weak
, visibility("hidden")));
261 struct tracepoint_dlopen tracepoint_dlopen
262 __attribute__((weak
, visibility("hidden")));
264 static void lttng_ust_notrace
__attribute__((constructor
))
265 __tracepoints__init(void);
267 __tracepoints__init(void)
269 if (__tracepoint_registered
++)
272 tracepoint_dlopen
.liblttngust_handle
=
273 dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW
| RTLD_GLOBAL
);
274 if (!tracepoint_dlopen
.liblttngust_handle
)
276 tracepoint_dlopen
.tracepoint_register_lib
=
277 URCU_FORCE_CAST(int (*)(struct tracepoint
* const *, int),
278 dlsym(tracepoint_dlopen
.liblttngust_handle
,
279 "tracepoint_register_lib"));
280 tracepoint_dlopen
.tracepoint_unregister_lib
=
281 URCU_FORCE_CAST(int (*)(struct tracepoint
* const *),
282 dlsym(tracepoint_dlopen
.liblttngust_handle
,
283 "tracepoint_unregister_lib"));
285 tracepoint_dlopen
.rcu_read_lock_sym_bp
=
286 URCU_FORCE_CAST(void (*)(void),
287 dlsym(tracepoint_dlopen
.liblttngust_handle
,
288 "tp_rcu_read_lock_bp"));
289 tracepoint_dlopen
.rcu_read_unlock_sym_bp
=
290 URCU_FORCE_CAST(void (*)(void),
291 dlsym(tracepoint_dlopen
.liblttngust_handle
,
292 "tp_rcu_read_unlock_bp"));
293 tracepoint_dlopen
.rcu_dereference_sym_bp
=
294 URCU_FORCE_CAST(void *(*)(void *p
),
295 dlsym(tracepoint_dlopen
.liblttngust_handle
,
296 "tp_rcu_dereference_sym_bp"));
298 tracepoint_dlopen
.tracepoint_register_lib(__start___tracepoints_ptrs
,
299 __stop___tracepoints_ptrs
-
300 __start___tracepoints_ptrs
);
303 static void lttng_ust_notrace
__attribute__((destructor
))
304 __tracepoints__destroy(void);
306 __tracepoints__destroy(void)
310 if (--__tracepoint_registered
)
312 if (tracepoint_dlopen
.tracepoint_unregister_lib
)
313 tracepoint_dlopen
.tracepoint_unregister_lib(__start___tracepoints_ptrs
);
314 if (tracepoint_dlopen
.liblttngust_handle
) {
315 ret
= dlclose(tracepoint_dlopen
.liblttngust_handle
);
317 memset(&tracepoint_dlopen
, 0, sizeof(tracepoint_dlopen
));
321 #else /* TRACEPOINT_DEFINE */
323 #define _DEFINE_TRACEPOINT(_provider, _name, _args)
325 #endif /* #else TRACEPOINT_DEFINE */
331 #endif /* _LTTNG_TRACEPOINT_H */
333 /* The following declarations must be outside re-inclusion protection. */
335 #ifndef TRACEPOINT_EVENT
338 * How to use the TRACEPOINT_EVENT macro:
342 * TRACEPOINT_EVENT(someproject_component, event_name,
344 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
346 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
347 * long *, arg4, size_t, arg4_len),
349 * * TP_FIELDS describes the event payload layout in the trace *
352 * * Integer, printed in base 10 *
353 * ctf_integer(int, field_a, arg0)
355 * * Integer, printed with 0x base 16 *
356 * ctf_integer_hex(unsigned long, field_d, arg1)
358 * * Array Sequence, printed as UTF8-encoded array of bytes *
359 * ctf_array_text(char, field_b, string, FIXED_LEN)
360 * ctf_sequence_text(char, field_c, string, size_t, strlen)
362 * * String, printed as UTF8-encoded string *
363 * ctf_string(field_e, string)
365 * * Array sequence of signed integer values *
366 * ctf_array(long, field_f, arg4, FIXED_LEN4)
367 * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
371 * More detailed explanation:
373 * The name of the tracepoint is expressed as a tuple with the provider
374 * and name arguments.
376 * The provider and name should be a proper C99 identifier.
377 * The "provider" and "name" MUST follow these rules to ensure no
378 * namespace clash occurs:
380 * For projects (applications and libraries) for which an entity
381 * specific to the project controls the source code and thus its
382 * tracepoints (typically with a scope larger than a single company):
385 * project_component, event
389 * Where "project" is the name of the project,
390 * "component" is the name of the project component (which may
391 * include several levels of sub-components, e.g.
392 * ...component_subcomponent_...) where the tracepoint is located
394 * "event" is the name of the tracepoint event.
396 * For projects issued from a single company wishing to advertise that
397 * the company controls the source code and thus the tracepoints, the
398 * "com_" prefix should be used:
401 * com_company_project_component, event
403 * com_company_project, event
405 * Where "company" is the name of the company,
406 * "project" is the name of the project,
407 * "component" is the name of the project component (which may
408 * include several levels of sub-components, e.g.
409 * ...component_subcomponent_...) where the tracepoint is located
411 * "event" is the name of the tracepoint event.
413 * the provider:event identifier is limited to 127 characters.
416 #define TRACEPOINT_EVENT(provider, name, args, fields) \
417 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
418 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
420 #define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
422 #define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
423 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
424 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
426 #endif /* #ifndef TRACEPOINT_EVENT */
428 #ifndef TRACEPOINT_LOGLEVEL
431 * Tracepoint Loglevels
433 * Typical use of these loglevels:
435 * The loglevels go from 0 to 14. Higher numbers imply the most
436 * verbosity (higher event throughput expected.
438 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
439 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
446 * action must be taken immediately
449 * critical conditions
458 * normal, but significant, condition
461 * informational message
463 * TRACE_DEBUG_SYSTEM 7
464 * debug information with system-level scope (set of programs)
466 * TRACE_DEBUG_PROGRAM 8
467 * debug information with program-level scope (set of processes)
469 * TRACE_DEBUG_PROCESS 9
470 * debug information with process-level scope (set of modules)
472 * TRACE_DEBUG_MODULE 10
473 * debug information with module (executable/library) scope (set of units)
475 * TRACE_DEBUG_UNIT 11
476 * debug information with compilation unit scope (set of functions)
478 * TRACE_DEBUG_FUNCTION 12
479 * debug information with function-level scope
481 * TRACE_DEBUG_LINE 13
482 * debug information with line-level scope (TRACEPOINT_EVENT default)
485 * debug-level message (trace_printf default)
487 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
488 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
489 * tracepoint name. The first field is the provider name, the second
490 * field is the name of the tracepoint, the third field is the loglevel
493 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
496 * The TRACEPOINT_PROVIDER must be already declared before declaring a
497 * TRACEPOINT_LOGLEVEL.
508 TRACE_DEBUG_SYSTEM
= 7,
509 TRACE_DEBUG_PROGRAM
= 8,
510 TRACE_DEBUG_PROCESS
= 9,
511 TRACE_DEBUG_MODULE
= 10,
512 TRACE_DEBUG_UNIT
= 11,
513 TRACE_DEBUG_FUNCTION
= 12,
514 TRACE_DEBUG_LINE
= 13,
518 #define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
520 #endif /* #ifndef TRACEPOINT_LOGLEVEL */
522 #ifndef TRACEPOINT_MODEL_EMF_URI
524 #define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
526 #endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */