2 * SPDX-License-Identifier: MIT
4 * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7 #ifndef _LTTNG_TRACEPOINT_H
8 #define _LTTNG_TRACEPOINT_H
12 #include <lttng/tracepoint-types.h>
13 #include <lttng/tracepoint-rcu.h>
14 #include <urcu/compiler.h>
15 #include <urcu/system.h>
16 #include <dlfcn.h> /* for dlopen */
17 #include <string.h> /* for memset */
19 #include <lttng/ust-config.h> /* for sdt */
20 #include <lttng/ust-compiler.h>
21 #include <lttng/ust-tracer.h>
23 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
25 * Instead of using SDT_USE_VARIADIC from 'sys/sdt.h', use our own namespaced
26 * macros since the instrumented application might already have included
27 * 'sys/sdt.h' without variadic support.
31 #define _LTTNG_SDT_NARG(...) \
32 __LTTNG_SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0)
34 #define __LTTNG_SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N
36 #define _LTTNG_SDT_PROBE_N(provider, name, N, ...) \
37 _SDT_PROBE(provider, name, N, (__VA_ARGS__))
39 #define LTTNG_STAP_PROBEV(provider, name, ...) \
40 _LTTNG_SDT_PROBE_N(provider, name, _LTTNG_SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__)
43 #define LTTNG_STAP_PROBEV(...)
50 #define tracepoint_enabled(provider, name) \
51 caa_unlikely(CMM_LOAD_SHARED(__tracepoint_##provider##___##name.state))
53 #define do_tracepoint(provider, name, ...) \
54 __tracepoint_cb_##provider##___##name(__VA_ARGS__)
56 #define tracepoint(provider, name, ...) \
58 LTTNG_STAP_PROBEV(provider, name, ## __VA_ARGS__); \
59 if (tracepoint_enabled(provider, name)) \
60 do_tracepoint(provider, name, __VA_ARGS__); \
63 #define TP_ARGS(...) __VA_ARGS__
66 * TP_ARGS takes tuples of type, argument separated by a comma.
67 * It can take up to 10 tuples (which means that less than 10 tuples is
69 * Each tuple is also separated by a comma.
71 #define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
73 #define _TP_COMBINE_TOKENS(_tokena, _tokenb) \
74 __TP_COMBINE_TOKENS(_tokena, _tokenb)
75 #define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
76 _tokena##_tokenb##_tokenc
77 #define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
78 __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
79 #define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
80 _tokena##_tokenb##_tokenc##_tokend
81 #define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
82 __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
85 * _TP_EXVAR* extract the var names.
86 * _TP_EXVAR1 and _TP_EXDATA_VAR1 are needed for -std=c99.
90 #define _TP_EXVAR2(a,b) b
91 #define _TP_EXVAR4(a,b,c,d) b,d
92 #define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
93 #define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
94 #define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
95 #define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
96 #define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
97 #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
98 #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
99 #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
101 #define _TP_EXDATA_VAR0() __tp_data
102 #define _TP_EXDATA_VAR1(a) __tp_data
103 #define _TP_EXDATA_VAR2(a,b) __tp_data,b
104 #define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
105 #define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
106 #define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
107 #define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
108 #define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
109 #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
110 #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
111 #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
112 #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
115 * _TP_EXPROTO* extract tuples of type, var.
116 * _TP_EXPROTO1 and _TP_EXDATA_PROTO1 are needed for -std=c99.
118 #define _TP_EXPROTO0() void
119 #define _TP_EXPROTO1(a) void
120 #define _TP_EXPROTO2(a,b) a b
121 #define _TP_EXPROTO4(a,b,c,d) a b,c d
122 #define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
123 #define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
124 #define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
125 #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
126 #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
127 #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
128 #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
129 #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
131 #define _TP_EXDATA_PROTO0() void *__tp_data
132 #define _TP_EXDATA_PROTO1(a) void *__tp_data
133 #define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
134 #define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
135 #define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
136 #define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
137 #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
138 #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
139 #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
140 #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
141 #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
142 #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
144 /* Preprocessor trick to count arguments. Inspired from sdt.h. */
145 #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)
146 #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
147 #define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
148 #define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
149 #define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
150 #define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
151 #define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
152 #define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
153 #define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
154 #define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
155 #define _TP_PARAMS(...) __VA_ARGS__
158 * The tracepoint cb is marked always inline so we can distinguish
159 * between caller's ip addresses within the probe using the return
162 #define _DECLARE_TRACEPOINT(_provider, _name, ...) \
163 extern struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name; \
165 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
166 __attribute__((always_inline, unused)) lttng_ust_notrace; \
168 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
170 struct lttng_ust_tracepoint_probe *__tp_probe; \
172 if (caa_unlikely(!TP_RCU_LINK_TEST())) \
174 tp_rcu_read_lock(); \
175 __tp_probe = tp_rcu_dereference(__tracepoint_##_provider##___##_name.probes); \
176 if (caa_unlikely(!__tp_probe)) \
179 void (*__tp_cb)(void) = __tp_probe->func; \
180 void *__tp_data = __tp_probe->data; \
182 URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
183 (_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
184 } while ((++__tp_probe)->func); \
186 tp_rcu_read_unlock(); \
188 static inline lttng_ust_notrace \
189 void __tracepoint_register_##_provider##___##_name(char *name, \
190 void (*func)(void), void *data); \
192 void __tracepoint_register_##_provider##___##_name(char *name, \
193 void (*func)(void), void *data) \
195 __tracepoint_probe_register(name, func, data, \
196 __tracepoint_##_provider##___##_name.signature); \
198 static inline lttng_ust_notrace \
199 void __tracepoint_unregister_##_provider##___##_name(char *name, \
200 void (*func)(void), void *data); \
202 void __tracepoint_unregister_##_provider##___##_name(char *name, \
203 void (*func)(void), void *data) \
205 __tracepoint_probe_unregister(name, func, data); \
208 extern int __tracepoint_probe_register(const char *name
, void (*func
)(void),
209 void *data
, const char *signature
);
210 extern int __tracepoint_probe_unregister(const char *name
, void (*func
)(void),
214 * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
215 * shared across objects in a module/main executable.
217 * IMPORTANT: this structure is part of the ABI between instrumented
218 * applications and UST. Fields need to be only added at the end, never
219 * reordered, never removed.
221 * The field @struct_size should be used to determine the size of the
222 * structure. It should be queried before using additional fields added
223 * at the end of the structure.
225 struct lttng_ust_tracepoint_dlopen
{
226 uint32_t struct_size
;
228 void *liblttngust_handle
;
230 int (*tracepoint_register_lib
)(struct lttng_ust_tracepoint
* const *tracepoints_start
,
231 int tracepoints_count
);
232 int (*tracepoint_unregister_lib
)(struct lttng_ust_tracepoint
* const *tracepoints_start
);
233 void (*rcu_read_lock_sym
)(void);
234 void (*rcu_read_unlock_sym
)(void);
235 void *(*rcu_dereference_sym
)(void *p
);
237 /* End of base ABI. Fields below should be used after checking struct_size. */
240 extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
;
241 extern struct lttng_ust_tracepoint_dlopen
*tracepoint_dlopen_ptr
;
244 * These weak symbols, the constructor, and destructor take care of
245 * registering only _one_ instance of the tracepoints per shared-ojbect
246 * (or for the whole main program).
248 int __tracepoint_registered
249 __attribute__((weak
, visibility("hidden")));
250 int __tracepoint_ptrs_registered
251 __attribute__((weak
, visibility("hidden")));
252 struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
253 __attribute__((weak
, visibility("hidden"))) = {
254 .struct_size
= sizeof(struct lttng_ust_tracepoint_dlopen
),
257 * Deal with gcc O1 optimisation issues with weak hidden symbols. gcc
258 * 4.8 and prior does not have the same behavior for symbol scoping on
259 * 32-bit powerpc depending on the object size: symbols for objects of 8
260 * bytes or less have the same address throughout a module, whereas they
261 * have different addresses between compile units for objects larger
262 * than 8 bytes. Add this pointer indirection to ensure that the symbol
263 * scoping match that of the other weak hidden symbols found in this
266 struct lttng_ust_tracepoint_dlopen
*tracepoint_dlopen_ptr
267 __attribute__((weak
, visibility("hidden")));
270 * Tracepoint dynamic linkage handling (callbacks). Hidden visibility: shared
271 * across objects in a module/main executable. The callbacks are used to
272 * control and check if the destructors should be executed.
274 * IMPORTANT: this structure is part of the ABI between instrumented
275 * applications and UST. Fields need to be only added at the end, never
276 * reordered, never removed.
278 * The field @struct_size should be used to determine the size of the
279 * structure. It should be queried before using additional fields added
280 * at the end of the structure.
282 struct lttng_ust_tracepoint_destructors_syms
{
283 uint32_t struct_size
;
285 void (*tracepoint_disable_destructors
)(void);
286 int (*tracepoint_get_destructors_state
)(void);
288 /* End of base ABI. Fields below should be used after checking struct_size. */
291 extern struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms
;
292 extern struct lttng_ust_tracepoint_destructors_syms
*tracepoint_destructors_syms_ptr
;
294 struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms
295 __attribute__((weak
, visibility("hidden"))) = {
296 .struct_size
= sizeof(struct lttng_ust_tracepoint_destructors_syms
),
298 struct lttng_ust_tracepoint_destructors_syms
*tracepoint_destructors_syms_ptr
299 __attribute__((weak
, visibility("hidden")));
301 static inline void tracepoint_disable_destructors(void)
303 if (!tracepoint_dlopen_ptr
)
304 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
305 if (!tracepoint_destructors_syms_ptr
)
306 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
307 if (tracepoint_dlopen_ptr
->liblttngust_handle
308 && tracepoint_destructors_syms_ptr
->tracepoint_disable_destructors
)
309 tracepoint_destructors_syms_ptr
->tracepoint_disable_destructors();
313 static inline void lttng_ust_notrace
314 __tracepoint__init_urcu_sym(void);
316 __tracepoint__init_urcu_sym(void)
318 if (!tracepoint_dlopen_ptr
)
319 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
321 * Symbols below are needed by tracepoint call sites and probe
324 if (!tracepoint_dlopen_ptr
->rcu_read_lock_sym
)
325 tracepoint_dlopen_ptr
->rcu_read_lock_sym
=
326 URCU_FORCE_CAST(void (*)(void),
327 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
328 "tp_rcu_read_lock"));
329 if (!tracepoint_dlopen_ptr
->rcu_read_unlock_sym
)
330 tracepoint_dlopen_ptr
->rcu_read_unlock_sym
=
331 URCU_FORCE_CAST(void (*)(void),
332 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
333 "tp_rcu_read_unlock"));
334 if (!tracepoint_dlopen_ptr
->rcu_dereference_sym
)
335 tracepoint_dlopen_ptr
->rcu_dereference_sym
=
336 URCU_FORCE_CAST(void *(*)(void *p
),
337 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
338 "tp_rcu_dereference_sym"));
341 static inline void lttng_ust_notrace
342 __tracepoint__init_urcu_sym(void);
344 __tracepoint__init_urcu_sym(void)
350 __tracepoints__init(void)
351 lttng_ust_notrace
__attribute__((constructor
));
353 __tracepoints__init(void)
355 if (__tracepoint_registered
++) {
356 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
358 __tracepoint__init_urcu_sym();
362 if (!tracepoint_dlopen_ptr
)
363 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
364 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
365 tracepoint_dlopen_ptr
->liblttngust_handle
=
366 dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME
, RTLD_NOW
| RTLD_GLOBAL
);
367 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
369 __tracepoint__init_urcu_sym();
373 __tracepoints__destroy(void)
374 lttng_ust_notrace
__attribute__((destructor
));
376 __tracepoints__destroy(void)
380 if (--__tracepoint_registered
)
382 if (!tracepoint_dlopen_ptr
)
383 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
384 if (!tracepoint_destructors_syms_ptr
)
385 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
386 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
388 if (__tracepoint_ptrs_registered
)
391 * Lookup if destructors must be executed using the new method.
393 if (tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state
394 && !tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state()) {
396 * The tracepoint_get_destructors_state symbol was found with
397 * dlsym but its returned value is 0 meaning that destructors
398 * must not be executed.
402 ret
= dlclose(tracepoint_dlopen_ptr
->liblttngust_handle
);
404 fprintf(stderr
, "Error (%d) in dlclose\n", ret
);
407 memset(tracepoint_dlopen_ptr
, 0, sizeof(*tracepoint_dlopen_ptr
));
410 #ifdef TRACEPOINT_DEFINE
413 * These weak symbols, the constructor, and destructor take care of
414 * registering only _one_ instance of the tracepoints per shared-ojbect
415 * (or for the whole main program).
417 extern struct lttng_ust_tracepoint
* const __start___tracepoints_ptrs
[]
418 __attribute__((weak
, visibility("hidden")));
419 extern struct lttng_ust_tracepoint
* const __stop___tracepoints_ptrs
[]
420 __attribute__((weak
, visibility("hidden")));
423 * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
424 * unresolved symbol that requires the provider to be linked in. When
425 * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
426 * unresolved symbol that depends on having the provider linked in,
427 * otherwise the linker complains. This deals with use of static
428 * libraries, ensuring that the linker does not remove the provider
429 * object from the executable.
431 #ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
432 #define _TRACEPOINT_UNDEFINED_REF(provider) NULL
433 #else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
434 #define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
435 #endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
438 * Note: to allow PIC code, we need to allow the linker to update the pointers
439 * in the __tracepoints_ptrs section.
440 * Therefore, this section is _not_ const (read-only).
442 #define _TP_EXTRACT_STRING(...) #__VA_ARGS__
444 #define _DEFINE_TRACEPOINT(_provider, _name, _args) \
445 extern int __tracepoint_provider_##_provider; \
446 static const char __tp_strtab_##_provider##___##_name[] \
447 __attribute__((section("__tracepoints_strings"))) = \
448 #_provider ":" #_name; \
449 struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name \
450 __attribute__((section("__tracepoints"))) = { \
451 sizeof(struct lttng_ust_tracepoint), \
452 __tp_strtab_##_provider##___##_name, \
455 _TRACEPOINT_UNDEFINED_REF(_provider), \
456 _TP_EXTRACT_STRING(_args), \
458 static struct lttng_ust_tracepoint * \
459 __tracepoint_ptr_##_provider##___##_name \
460 __attribute__((section("__tracepoints_ptrs"), used)) \
461 __lttng_ust_variable_attribute_no_sanitize_address = \
462 &__tracepoint_##_provider##___##_name;
465 __tracepoints__ptrs_init(void)
466 lttng_ust_notrace
__attribute__((constructor
));
468 __tracepoints__ptrs_init(void)
470 if (__tracepoint_ptrs_registered
++)
472 if (!tracepoint_dlopen_ptr
)
473 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
474 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
475 tracepoint_dlopen_ptr
->liblttngust_handle
=
476 dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME
, RTLD_NOW
| RTLD_GLOBAL
);
477 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
479 if (!tracepoint_destructors_syms_ptr
)
480 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
481 tracepoint_dlopen_ptr
->tracepoint_register_lib
=
482 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint
* const *, int),
483 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
484 "tracepoint_register_lib"));
485 tracepoint_dlopen_ptr
->tracepoint_unregister_lib
=
486 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint
* const *),
487 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
488 "tracepoint_unregister_lib"));
489 tracepoint_destructors_syms_ptr
->tracepoint_disable_destructors
=
490 URCU_FORCE_CAST(void (*)(void),
491 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
492 "tp_disable_destructors"));
493 tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state
=
494 URCU_FORCE_CAST(int (*)(void),
495 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
496 "tp_get_destructors_state"));
497 __tracepoint__init_urcu_sym();
498 if (tracepoint_dlopen_ptr
->tracepoint_register_lib
) {
499 tracepoint_dlopen_ptr
->tracepoint_register_lib(__start___tracepoints_ptrs
,
500 __stop___tracepoints_ptrs
-
501 __start___tracepoints_ptrs
);
506 __tracepoints__ptrs_destroy(void)
507 lttng_ust_notrace
__attribute__((destructor
));
509 __tracepoints__ptrs_destroy(void)
513 if (--__tracepoint_ptrs_registered
)
515 if (!tracepoint_dlopen_ptr
)
516 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
517 if (!tracepoint_destructors_syms_ptr
)
518 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
519 if (tracepoint_dlopen_ptr
->tracepoint_unregister_lib
)
520 tracepoint_dlopen_ptr
->tracepoint_unregister_lib(__start___tracepoints_ptrs
);
521 if (tracepoint_dlopen_ptr
->liblttngust_handle
522 && tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state
523 && tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state()
524 && !__tracepoint_ptrs_registered
) {
525 ret
= dlclose(tracepoint_dlopen_ptr
->liblttngust_handle
);
527 fprintf(stderr
, "Error (%d) in dlclose\n", ret
);
530 memset(tracepoint_dlopen_ptr
, 0, sizeof(*tracepoint_dlopen_ptr
));
534 #else /* TRACEPOINT_DEFINE */
536 #define _DEFINE_TRACEPOINT(_provider, _name, _args)
538 #endif /* #else TRACEPOINT_DEFINE */
544 #endif /* _LTTNG_TRACEPOINT_H */
546 /* The following declarations must be outside re-inclusion protection. */
548 #ifndef TRACEPOINT_ENUM
551 * Tracepoint Enumerations
553 * The enumeration is a mapping between an integer, or range of integers, and
554 * a string. It can be used to have a more compact trace in cases where the
555 * possible values for a field are limited:
559 * TRACEPOINT_ENUM(someproject_component, enumname,
561 * ctf_enum_value("even", 0)
562 * ctf_enum_value("uneven", 1)
563 * ctf_enum_range("twoto4", 2, 4)
564 * ctf_enum_value("five", 5)
568 * Where "someproject_component" is the name of the component this enumeration
569 * belongs to and "enumname" identifies this enumeration. Inside the
570 * TP_ENUM_VALUES macro is the actual mapping. Each string value can map
571 * to either a single value with ctf_enum_value or a range of values
572 * with ctf_enum_range.
574 * Enumeration ranges may overlap, but the behavior is implementation-defined,
575 * each trace reader will handle overlapping as it wishes.
577 * That enumeration can then be used in a field inside the TP_FIELD macro using
578 * the following line:
580 * ctf_enum(someproject_component, enumname, enumtype, enumfield, enumval)
582 * Where "someproject_component" and "enumname" match those in the
583 * TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
584 * backing the enumeration, "enumfield" is the name of the field and
585 * "enumval" is the value.
588 #define TRACEPOINT_ENUM(provider, name, values)
590 #endif /* #ifndef TRACEPOINT_ENUM */
592 #ifndef TRACEPOINT_EVENT
595 * How to use the TRACEPOINT_EVENT macro:
599 * TRACEPOINT_EVENT(someproject_component, event_name,
601 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
603 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
604 * long *, arg4, size_t, arg4_len),
606 * * TP_FIELDS describes the event payload layout in the trace *
609 * * Integer, printed in base 10 *
610 * ctf_integer(int, field_a, arg0)
612 * * Integer, printed with 0x base 16 *
613 * ctf_integer_hex(unsigned long, field_d, arg1)
616 * ctf_enum(someproject_component, enum_name, int, field_e, arg0)
618 * * Array Sequence, printed as UTF8-encoded array of bytes *
619 * ctf_array_text(char, field_b, string, FIXED_LEN)
620 * ctf_sequence_text(char, field_c, string, size_t, strlen)
622 * * String, printed as UTF8-encoded string *
623 * ctf_string(field_e, string)
625 * * Array sequence of signed integer values *
626 * ctf_array(long, field_f, arg4, FIXED_LEN4)
627 * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
631 * More detailed explanation:
633 * The name of the tracepoint is expressed as a tuple with the provider
634 * and name arguments.
636 * The provider and name should be a proper C99 identifier.
637 * The "provider" and "name" MUST follow these rules to ensure no
638 * namespace clash occurs:
640 * For projects (applications and libraries) for which an entity
641 * specific to the project controls the source code and thus its
642 * tracepoints (typically with a scope larger than a single company):
645 * project_component, event
649 * Where "project" is the name of the project,
650 * "component" is the name of the project component (which may
651 * include several levels of sub-components, e.g.
652 * ...component_subcomponent_...) where the tracepoint is located
654 * "event" is the name of the tracepoint event.
656 * For projects issued from a single company wishing to advertise that
657 * the company controls the source code and thus the tracepoints, the
658 * "com_" prefix should be used:
661 * com_company_project_component, event
663 * com_company_project, event
665 * Where "company" is the name of the company,
666 * "project" is the name of the project,
667 * "component" is the name of the project component (which may
668 * include several levels of sub-components, e.g.
669 * ...component_subcomponent_...) where the tracepoint is located
671 * "event" is the name of the tracepoint event.
673 * the provider:event identifier is limited to 127 characters.
676 #define TRACEPOINT_EVENT(provider, name, args, fields) \
677 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
678 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
680 #define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
682 #define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
683 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
684 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
686 #endif /* #ifndef TRACEPOINT_EVENT */
688 #ifndef TRACEPOINT_LOGLEVEL
691 * Tracepoint Loglevels
693 * Typical use of these loglevels:
695 * The loglevels go from 0 to 14. Higher numbers imply the most
696 * verbosity (higher event throughput expected.
698 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
699 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
706 * action must be taken immediately
709 * critical conditions
718 * normal, but significant, condition
721 * informational message
723 * TRACE_DEBUG_SYSTEM 7
724 * debug information with system-level scope (set of programs)
726 * TRACE_DEBUG_PROGRAM 8
727 * debug information with program-level scope (set of processes)
729 * TRACE_DEBUG_PROCESS 9
730 * debug information with process-level scope (set of modules)
732 * TRACE_DEBUG_MODULE 10
733 * debug information with module (executable/library) scope (set of units)
735 * TRACE_DEBUG_UNIT 11
736 * debug information with compilation unit scope (set of functions)
738 * TRACE_DEBUG_FUNCTION 12
739 * debug information with function-level scope
741 * TRACE_DEBUG_LINE 13
742 * debug information with line-level scope (TRACEPOINT_EVENT default)
745 * debug-level message
747 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
748 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
749 * tracepoint name. The first field is the provider name, the second
750 * field is the name of the tracepoint, the third field is the loglevel
753 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
756 * The TRACEPOINT_PROVIDER must be already declared before declaring a
757 * TRACEPOINT_LOGLEVEL.
768 TRACE_DEBUG_SYSTEM
= 7,
769 TRACE_DEBUG_PROGRAM
= 8,
770 TRACE_DEBUG_PROCESS
= 9,
771 TRACE_DEBUG_MODULE
= 10,
772 TRACE_DEBUG_UNIT
= 11,
773 TRACE_DEBUG_FUNCTION
= 12,
774 TRACE_DEBUG_LINE
= 13,
778 #define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
780 #endif /* #ifndef TRACEPOINT_LOGLEVEL */
782 #ifndef TRACEPOINT_MODEL_EMF_URI
784 #define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
786 #endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */