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; \
164 static inline __attribute__((always_inline, unused)) lttng_ust_notrace \
165 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)); \
167 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
169 struct lttng_ust_tracepoint_probe *__tp_probe; \
171 if (caa_unlikely(!TP_RCU_LINK_TEST())) \
173 tp_rcu_read_lock(); \
174 __tp_probe = tp_rcu_dereference(__tracepoint_##_provider##___##_name.probes); \
175 if (caa_unlikely(!__tp_probe)) \
178 void (*__tp_cb)(void) = __tp_probe->func; \
179 void *__tp_data = __tp_probe->data; \
181 URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
182 (_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
183 } while ((++__tp_probe)->func); \
185 tp_rcu_read_unlock(); \
187 static inline lttng_ust_notrace \
188 void __tracepoint_register_##_provider##___##_name(char *name, \
189 void (*func)(void), void *data); \
191 void __tracepoint_register_##_provider##___##_name(char *name, \
192 void (*func)(void), void *data) \
194 __tracepoint_probe_register(name, func, data, \
195 __tracepoint_##_provider##___##_name.signature); \
197 static inline lttng_ust_notrace \
198 void __tracepoint_unregister_##_provider##___##_name(char *name, \
199 void (*func)(void), void *data); \
201 void __tracepoint_unregister_##_provider##___##_name(char *name, \
202 void (*func)(void), void *data) \
204 __tracepoint_probe_unregister(name, func, data); \
207 extern int __tracepoint_probe_register(const char *name
, void (*func
)(void),
208 void *data
, const char *signature
);
209 extern int __tracepoint_probe_unregister(const char *name
, void (*func
)(void),
213 * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
214 * shared across objects in a module/main executable.
216 * IMPORTANT: this structure is part of the ABI between instrumented
217 * applications and UST. Fields need to be only added at the end, never
218 * reordered, never removed.
220 * The field @struct_size should be used to determine the size of the
221 * structure. It should be queried before using additional fields added
222 * at the end of the structure.
224 struct lttng_ust_tracepoint_dlopen
{
225 uint32_t struct_size
;
227 void *liblttngust_handle
;
229 int (*tracepoint_register_lib
)(struct lttng_ust_tracepoint
* const *tracepoints_start
,
230 int tracepoints_count
);
231 int (*tracepoint_unregister_lib
)(struct lttng_ust_tracepoint
* const *tracepoints_start
);
232 void (*rcu_read_lock_sym
)(void);
233 void (*rcu_read_unlock_sym
)(void);
234 void *(*rcu_dereference_sym
)(void *p
);
236 /* End of base ABI. Fields below should be used after checking struct_size. */
239 extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
;
240 extern struct lttng_ust_tracepoint_dlopen
*tracepoint_dlopen_ptr
;
243 * These weak symbols, the constructor, and destructor take care of
244 * registering only _one_ instance of the tracepoints per shared-ojbect
245 * (or for the whole main program).
247 int __tracepoint_registered
248 __attribute__((weak
, visibility("hidden")));
249 int __tracepoint_ptrs_registered
250 __attribute__((weak
, visibility("hidden")));
251 struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
252 __attribute__((weak
, visibility("hidden"))) = {
253 .struct_size
= sizeof(struct lttng_ust_tracepoint_dlopen
),
256 * Deal with gcc O1 optimisation issues with weak hidden symbols. gcc
257 * 4.8 and prior does not have the same behavior for symbol scoping on
258 * 32-bit powerpc depending on the object size: symbols for objects of 8
259 * bytes or less have the same address throughout a module, whereas they
260 * have different addresses between compile units for objects larger
261 * than 8 bytes. Add this pointer indirection to ensure that the symbol
262 * scoping match that of the other weak hidden symbols found in this
265 struct lttng_ust_tracepoint_dlopen
*tracepoint_dlopen_ptr
266 __attribute__((weak
, visibility("hidden")));
269 * Tracepoint dynamic linkage handling (callbacks). Hidden visibility: shared
270 * across objects in a module/main executable. The callbacks are used to
271 * control and check if the destructors should be executed.
273 * IMPORTANT: this structure is part of the ABI between instrumented
274 * applications and UST. Fields need to be only added at the end, never
275 * reordered, never removed.
277 * The field @struct_size should be used to determine the size of the
278 * structure. It should be queried before using additional fields added
279 * at the end of the structure.
281 struct lttng_ust_tracepoint_destructors_syms
{
282 uint32_t struct_size
;
284 void (*tracepoint_disable_destructors
)(void);
285 int (*tracepoint_get_destructors_state
)(void);
287 /* End of base ABI. Fields below should be used after checking struct_size. */
290 extern struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms
;
291 extern struct lttng_ust_tracepoint_destructors_syms
*tracepoint_destructors_syms_ptr
;
293 struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms
294 __attribute__((weak
, visibility("hidden"))) = {
295 .struct_size
= sizeof(struct lttng_ust_tracepoint_destructors_syms
),
297 struct lttng_ust_tracepoint_destructors_syms
*tracepoint_destructors_syms_ptr
298 __attribute__((weak
, visibility("hidden")));
300 static inline void tracepoint_disable_destructors(void)
302 if (!tracepoint_dlopen_ptr
)
303 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
304 if (!tracepoint_destructors_syms_ptr
)
305 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
306 if (tracepoint_dlopen_ptr
->liblttngust_handle
307 && tracepoint_destructors_syms_ptr
->tracepoint_disable_destructors
)
308 tracepoint_destructors_syms_ptr
->tracepoint_disable_destructors();
312 static inline void lttng_ust_notrace
313 __tracepoint__init_urcu_sym(void);
315 __tracepoint__init_urcu_sym(void)
317 if (!tracepoint_dlopen_ptr
)
318 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
320 * Symbols below are needed by tracepoint call sites and probe
323 if (!tracepoint_dlopen_ptr
->rcu_read_lock_sym
)
324 tracepoint_dlopen_ptr
->rcu_read_lock_sym
=
325 URCU_FORCE_CAST(void (*)(void),
326 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
327 "tp_rcu_read_lock"));
328 if (!tracepoint_dlopen_ptr
->rcu_read_unlock_sym
)
329 tracepoint_dlopen_ptr
->rcu_read_unlock_sym
=
330 URCU_FORCE_CAST(void (*)(void),
331 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
332 "tp_rcu_read_unlock"));
333 if (!tracepoint_dlopen_ptr
->rcu_dereference_sym
)
334 tracepoint_dlopen_ptr
->rcu_dereference_sym
=
335 URCU_FORCE_CAST(void *(*)(void *p
),
336 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
337 "tp_rcu_dereference_sym"));
340 static inline void lttng_ust_notrace
341 __tracepoint__init_urcu_sym(void);
343 __tracepoint__init_urcu_sym(void)
348 static void lttng_ust_notrace
__attribute__((constructor
))
349 __tracepoints__init(void);
351 __tracepoints__init(void)
353 if (__tracepoint_registered
++) {
354 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
356 __tracepoint__init_urcu_sym();
360 if (!tracepoint_dlopen_ptr
)
361 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
362 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
363 tracepoint_dlopen_ptr
->liblttngust_handle
=
364 dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME
, RTLD_NOW
| RTLD_GLOBAL
);
365 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
367 __tracepoint__init_urcu_sym();
370 static void lttng_ust_notrace
__attribute__((destructor
))
371 __tracepoints__destroy(void);
373 __tracepoints__destroy(void)
377 if (--__tracepoint_registered
)
379 if (!tracepoint_dlopen_ptr
)
380 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
381 if (!tracepoint_destructors_syms_ptr
)
382 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
383 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
385 if (__tracepoint_ptrs_registered
)
388 * Lookup if destructors must be executed using the new method.
390 if (tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state
391 && !tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state()) {
393 * The tracepoint_get_destructors_state symbol was found with
394 * dlsym but its returned value is 0 meaning that destructors
395 * must not be executed.
399 ret
= dlclose(tracepoint_dlopen_ptr
->liblttngust_handle
);
401 fprintf(stderr
, "Error (%d) in dlclose\n", ret
);
404 memset(tracepoint_dlopen_ptr
, 0, sizeof(*tracepoint_dlopen_ptr
));
407 #ifdef TRACEPOINT_DEFINE
410 * These weak symbols, the constructor, and destructor take care of
411 * registering only _one_ instance of the tracepoints per shared-ojbect
412 * (or for the whole main program).
414 extern struct lttng_ust_tracepoint
* const __start___tracepoints_ptrs
[]
415 __attribute__((weak
, visibility("hidden")));
416 extern struct lttng_ust_tracepoint
* const __stop___tracepoints_ptrs
[]
417 __attribute__((weak
, visibility("hidden")));
420 * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
421 * unresolved symbol that requires the provider to be linked in. When
422 * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
423 * unresolved symbol that depends on having the provider linked in,
424 * otherwise the linker complains. This deals with use of static
425 * libraries, ensuring that the linker does not remove the provider
426 * object from the executable.
428 #ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
429 #define _TRACEPOINT_UNDEFINED_REF(provider) NULL
430 #else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
431 #define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
432 #endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
435 * Note: to allow PIC code, we need to allow the linker to update the pointers
436 * in the __tracepoints_ptrs section.
437 * Therefore, this section is _not_ const (read-only).
439 #define _TP_EXTRACT_STRING(...) #__VA_ARGS__
441 #define _DEFINE_TRACEPOINT(_provider, _name, _args) \
442 extern int __tracepoint_provider_##_provider; \
443 static const char __tp_strtab_##_provider##___##_name[] \
444 __attribute__((section("__tracepoints_strings"))) = \
445 #_provider ":" #_name; \
446 struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name \
447 __attribute__((section("__tracepoints"))) = { \
448 sizeof(struct lttng_ust_tracepoint), \
449 __tp_strtab_##_provider##___##_name, \
452 _TRACEPOINT_UNDEFINED_REF(_provider), \
453 _TP_EXTRACT_STRING(_args), \
455 static struct lttng_ust_tracepoint * \
456 __tracepoint_ptr_##_provider##___##_name \
457 __attribute__((section("__tracepoints_ptrs"), used)) \
458 __lttng_ust_variable_attribute_no_sanitize_address = \
459 &__tracepoint_##_provider##___##_name;
461 static void lttng_ust_notrace
__attribute__((constructor
))
462 __tracepoints__ptrs_init(void);
464 __tracepoints__ptrs_init(void)
466 if (__tracepoint_ptrs_registered
++)
468 if (!tracepoint_dlopen_ptr
)
469 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
470 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
471 tracepoint_dlopen_ptr
->liblttngust_handle
=
472 dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME
, RTLD_NOW
| RTLD_GLOBAL
);
473 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
475 if (!tracepoint_destructors_syms_ptr
)
476 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
477 tracepoint_dlopen_ptr
->tracepoint_register_lib
=
478 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint
* const *, int),
479 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
480 "tracepoint_register_lib"));
481 tracepoint_dlopen_ptr
->tracepoint_unregister_lib
=
482 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint
* const *),
483 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
484 "tracepoint_unregister_lib"));
485 tracepoint_destructors_syms_ptr
->tracepoint_disable_destructors
=
486 URCU_FORCE_CAST(void (*)(void),
487 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
488 "tp_disable_destructors"));
489 tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state
=
490 URCU_FORCE_CAST(int (*)(void),
491 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
492 "tp_get_destructors_state"));
493 __tracepoint__init_urcu_sym();
494 if (tracepoint_dlopen_ptr
->tracepoint_register_lib
) {
495 tracepoint_dlopen_ptr
->tracepoint_register_lib(__start___tracepoints_ptrs
,
496 __stop___tracepoints_ptrs
-
497 __start___tracepoints_ptrs
);
501 static void lttng_ust_notrace
__attribute__((destructor
))
502 __tracepoints__ptrs_destroy(void);
504 __tracepoints__ptrs_destroy(void)
508 if (--__tracepoint_ptrs_registered
)
510 if (!tracepoint_dlopen_ptr
)
511 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
512 if (!tracepoint_destructors_syms_ptr
)
513 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
514 if (tracepoint_dlopen_ptr
->tracepoint_unregister_lib
)
515 tracepoint_dlopen_ptr
->tracepoint_unregister_lib(__start___tracepoints_ptrs
);
516 if (tracepoint_dlopen_ptr
->liblttngust_handle
517 && tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state
518 && tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state()
519 && !__tracepoint_ptrs_registered
) {
520 ret
= dlclose(tracepoint_dlopen_ptr
->liblttngust_handle
);
522 fprintf(stderr
, "Error (%d) in dlclose\n", ret
);
525 memset(tracepoint_dlopen_ptr
, 0, sizeof(*tracepoint_dlopen_ptr
));
529 #else /* TRACEPOINT_DEFINE */
531 #define _DEFINE_TRACEPOINT(_provider, _name, _args)
533 #endif /* #else TRACEPOINT_DEFINE */
539 #endif /* _LTTNG_TRACEPOINT_H */
541 /* The following declarations must be outside re-inclusion protection. */
543 #ifndef TRACEPOINT_ENUM
546 * Tracepoint Enumerations
548 * The enumeration is a mapping between an integer, or range of integers, and
549 * a string. It can be used to have a more compact trace in cases where the
550 * possible values for a field are limited:
554 * TRACEPOINT_ENUM(someproject_component, enumname,
556 * ctf_enum_value("even", 0)
557 * ctf_enum_value("uneven", 1)
558 * ctf_enum_range("twoto4", 2, 4)
559 * ctf_enum_value("five", 5)
563 * Where "someproject_component" is the name of the component this enumeration
564 * belongs to and "enumname" identifies this enumeration. Inside the
565 * TP_ENUM_VALUES macro is the actual mapping. Each string value can map
566 * to either a single value with ctf_enum_value or a range of values
567 * with ctf_enum_range.
569 * Enumeration ranges may overlap, but the behavior is implementation-defined,
570 * each trace reader will handle overlapping as it wishes.
572 * That enumeration can then be used in a field inside the TP_FIELD macro using
573 * the following line:
575 * ctf_enum(someproject_component, enumname, enumtype, enumfield, enumval)
577 * Where "someproject_component" and "enumname" match those in the
578 * TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
579 * backing the enumeration, "enumfield" is the name of the field and
580 * "enumval" is the value.
583 #define TRACEPOINT_ENUM(provider, name, values)
585 #endif /* #ifndef TRACEPOINT_ENUM */
587 #ifndef TRACEPOINT_EVENT
590 * How to use the TRACEPOINT_EVENT macro:
594 * TRACEPOINT_EVENT(someproject_component, event_name,
596 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
598 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
599 * long *, arg4, size_t, arg4_len),
601 * * TP_FIELDS describes the event payload layout in the trace *
604 * * Integer, printed in base 10 *
605 * ctf_integer(int, field_a, arg0)
607 * * Integer, printed with 0x base 16 *
608 * ctf_integer_hex(unsigned long, field_d, arg1)
611 * ctf_enum(someproject_component, enum_name, int, field_e, arg0)
613 * * Array Sequence, printed as UTF8-encoded array of bytes *
614 * ctf_array_text(char, field_b, string, FIXED_LEN)
615 * ctf_sequence_text(char, field_c, string, size_t, strlen)
617 * * String, printed as UTF8-encoded string *
618 * ctf_string(field_e, string)
620 * * Array sequence of signed integer values *
621 * ctf_array(long, field_f, arg4, FIXED_LEN4)
622 * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
626 * More detailed explanation:
628 * The name of the tracepoint is expressed as a tuple with the provider
629 * and name arguments.
631 * The provider and name should be a proper C99 identifier.
632 * The "provider" and "name" MUST follow these rules to ensure no
633 * namespace clash occurs:
635 * For projects (applications and libraries) for which an entity
636 * specific to the project controls the source code and thus its
637 * tracepoints (typically with a scope larger than a single company):
640 * project_component, event
644 * Where "project" is the name of the project,
645 * "component" is the name of the project component (which may
646 * include several levels of sub-components, e.g.
647 * ...component_subcomponent_...) where the tracepoint is located
649 * "event" is the name of the tracepoint event.
651 * For projects issued from a single company wishing to advertise that
652 * the company controls the source code and thus the tracepoints, the
653 * "com_" prefix should be used:
656 * com_company_project_component, event
658 * com_company_project, event
660 * Where "company" is the name of the company,
661 * "project" is the name of the project,
662 * "component" is the name of the project component (which may
663 * include several levels of sub-components, e.g.
664 * ...component_subcomponent_...) where the tracepoint is located
666 * "event" is the name of the tracepoint event.
668 * the provider:event identifier is limited to 127 characters.
671 #define TRACEPOINT_EVENT(provider, name, args, fields) \
672 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
673 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
675 #define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
677 #define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
678 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
679 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
681 #endif /* #ifndef TRACEPOINT_EVENT */
683 #ifndef TRACEPOINT_LOGLEVEL
686 * Tracepoint Loglevels
688 * Typical use of these loglevels:
690 * The loglevels go from 0 to 14. Higher numbers imply the most
691 * verbosity (higher event throughput expected.
693 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
694 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
701 * action must be taken immediately
704 * critical conditions
713 * normal, but significant, condition
716 * informational message
718 * TRACE_DEBUG_SYSTEM 7
719 * debug information with system-level scope (set of programs)
721 * TRACE_DEBUG_PROGRAM 8
722 * debug information with program-level scope (set of processes)
724 * TRACE_DEBUG_PROCESS 9
725 * debug information with process-level scope (set of modules)
727 * TRACE_DEBUG_MODULE 10
728 * debug information with module (executable/library) scope (set of units)
730 * TRACE_DEBUG_UNIT 11
731 * debug information with compilation unit scope (set of functions)
733 * TRACE_DEBUG_FUNCTION 12
734 * debug information with function-level scope
736 * TRACE_DEBUG_LINE 13
737 * debug information with line-level scope (TRACEPOINT_EVENT default)
740 * debug-level message
742 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
743 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
744 * tracepoint name. The first field is the provider name, the second
745 * field is the name of the tracepoint, the third field is the loglevel
748 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
751 * The TRACEPOINT_PROVIDER must be already declared before declaring a
752 * TRACEPOINT_LOGLEVEL.
763 TRACE_DEBUG_SYSTEM
= 7,
764 TRACE_DEBUG_PROGRAM
= 8,
765 TRACE_DEBUG_PROCESS
= 9,
766 TRACE_DEBUG_MODULE
= 10,
767 TRACE_DEBUG_UNIT
= 11,
768 TRACE_DEBUG_FUNCTION
= 12,
769 TRACE_DEBUG_LINE
= 13,
773 #define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
775 #endif /* #ifndef TRACEPOINT_LOGLEVEL */
777 #ifndef TRACEPOINT_MODEL_EMF_URI
779 #define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
781 #endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */