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.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
28 #include <lttng/tracepoint-types.h>
29 #include <lttng/tracepoint-rcu.h>
30 #include <urcu/compiler.h>
31 #include <urcu/system.h>
32 #include <dlfcn.h> /* for dlopen */
33 #include <string.h> /* for memset */
34 #include <lttng/ust-config.h> /* for sdt */
35 #include <lttng/ust-compiler.h>
37 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
39 * Instead of using SDT_USE_VARIADIC from 'sys/sdt.h', use our own namespaced
40 * macros since the instrumented application might already have included
41 * 'sys/sdt.h' without variadic support.
45 #define _LTTNG_SDT_NARG(...) \
46 __LTTNG_SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0)
48 #define __LTTNG_SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N
50 #define _LTTNG_SDT_PROBE_N(provider, name, N, ...) \
51 _SDT_PROBE(provider, name, N, (__VA_ARGS__))
53 #define LTTNG_STAP_PROBEV(provider, name, ...) \
54 _LTTNG_SDT_PROBE_N(provider, name, _LTTNG_SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__)
57 #define LTTNG_STAP_PROBEV(...)
64 #define tracepoint_enabled(provider, name) \
65 caa_unlikely(CMM_LOAD_SHARED(__tracepoint_##provider##___##name.state))
67 #define do_tracepoint(provider, name, ...) \
68 __tracepoint_cb_##provider##___##name(__VA_ARGS__)
70 #define tracepoint(provider, name, ...) \
72 LTTNG_STAP_PROBEV(provider, name, ## __VA_ARGS__); \
73 if (tracepoint_enabled(provider, name)) \
74 do_tracepoint(provider, name, __VA_ARGS__); \
77 #define TP_ARGS(...) __VA_ARGS__
80 * TP_ARGS takes tuples of type, argument separated by a comma.
81 * It can take up to 10 tuples (which means that less than 10 tuples is
83 * Each tuple is also separated by a comma.
85 #define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
87 #define _TP_COMBINE_TOKENS(_tokena, _tokenb) \
88 __TP_COMBINE_TOKENS(_tokena, _tokenb)
89 #define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
90 _tokena##_tokenb##_tokenc
91 #define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
92 __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
93 #define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
94 _tokena##_tokenb##_tokenc##_tokend
95 #define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
96 __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
99 * _TP_EXVAR* extract the var names.
100 * _TP_EXVAR1 and _TP_EXDATA_VAR1 are needed for -std=c99.
103 #define _TP_EXVAR1(a)
104 #define _TP_EXVAR2(a,b) b
105 #define _TP_EXVAR4(a,b,c,d) b,d
106 #define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
107 #define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
108 #define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
109 #define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
110 #define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
111 #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
112 #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
113 #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
115 #define _TP_EXDATA_VAR0() __tp_data
116 #define _TP_EXDATA_VAR1(a) __tp_data
117 #define _TP_EXDATA_VAR2(a,b) __tp_data,b
118 #define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
119 #define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
120 #define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
121 #define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
122 #define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
123 #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
124 #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
125 #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
126 #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
129 * _TP_EXPROTO* extract tuples of type, var.
130 * _TP_EXPROTO1 and _TP_EXDATA_PROTO1 are needed for -std=c99.
132 #define _TP_EXPROTO0() void
133 #define _TP_EXPROTO1(a) void
134 #define _TP_EXPROTO2(a,b) a b
135 #define _TP_EXPROTO4(a,b,c,d) a b,c d
136 #define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
137 #define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
138 #define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
139 #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
140 #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
141 #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
142 #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
143 #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
145 #define _TP_EXDATA_PROTO0() void *__tp_data
146 #define _TP_EXDATA_PROTO1(a) void *__tp_data
147 #define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
148 #define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
149 #define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
150 #define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
151 #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
152 #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
153 #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
154 #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
155 #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
156 #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
158 /* Preprocessor trick to count arguments. Inspired from sdt.h. */
159 #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)
160 #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
161 #define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
162 #define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
163 #define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
164 #define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
165 #define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
166 #define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
167 #define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
168 #define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
169 #define _TP_PARAMS(...) __VA_ARGS__
172 * The tracepoint cb is marked always inline so we can distinguish
173 * between caller's ip addresses within the probe using the return
176 #define _DECLARE_TRACEPOINT(_provider, _name, ...) \
177 extern struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name; \
178 static inline __attribute__((always_inline, unused)) lttng_ust_notrace \
179 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)); \
181 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
183 struct lttng_ust_tracepoint_probe *__tp_probe; \
185 if (caa_unlikely(!TP_RCU_LINK_TEST())) \
187 tp_rcu_read_lock_bp(); \
188 __tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
189 if (caa_unlikely(!__tp_probe)) \
192 void (*__tp_cb)(void) = __tp_probe->func; \
193 void *__tp_data = __tp_probe->data; \
195 URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
196 (_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
197 } while ((++__tp_probe)->func); \
199 tp_rcu_read_unlock_bp(); \
201 static inline lttng_ust_notrace \
202 void __tracepoint_register_##_provider##___##_name(char *name, \
203 void (*func)(void), void *data); \
205 void __tracepoint_register_##_provider##___##_name(char *name, \
206 void (*func)(void), void *data) \
208 __tracepoint_probe_register(name, func, data, \
209 __tracepoint_##_provider##___##_name.signature); \
211 static inline lttng_ust_notrace \
212 void __tracepoint_unregister_##_provider##___##_name(char *name, \
213 void (*func)(void), void *data); \
215 void __tracepoint_unregister_##_provider##___##_name(char *name, \
216 void (*func)(void), void *data) \
218 __tracepoint_probe_unregister(name, func, data); \
221 extern int __tracepoint_probe_register(const char *name
, void (*func
)(void),
222 void *data
, const char *signature
);
223 extern int __tracepoint_probe_unregister(const char *name
, void (*func
)(void),
227 * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
228 * shared across objects in a module/main executable.
230 struct lttng_ust_tracepoint_dlopen
{
231 void *liblttngust_handle
;
233 int (*tracepoint_register_lib
)(struct lttng_ust_tracepoint
* const *tracepoints_start
,
234 int tracepoints_count
);
235 int (*tracepoint_unregister_lib
)(struct lttng_ust_tracepoint
* const *tracepoints_start
);
236 void (*rcu_read_lock_sym_bp
)(void);
237 void (*rcu_read_unlock_sym_bp
)(void);
238 void *(*rcu_dereference_sym_bp
)(void *p
);
241 extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
;
242 extern struct lttng_ust_tracepoint_dlopen
*tracepoint_dlopen_ptr
;
245 * These weak symbols, the constructor, and destructor take care of
246 * registering only _one_ instance of the tracepoints per shared-ojbect
247 * (or for the whole main program).
249 int __tracepoint_registered
250 __attribute__((weak
, visibility("hidden")));
251 int __tracepoint_ptrs_registered
252 __attribute__((weak
, visibility("hidden")));
253 struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
254 __attribute__((weak
, visibility("hidden")));
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 struct lttng_ust_tracepoint_destructors_syms
{
274 int *old_tracepoint_disable_destructors
;
275 void (*tracepoint_disable_destructors
)(void);
276 int (*tracepoint_get_destructors_state
)(void);
279 extern struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms
;
280 extern struct lttng_ust_tracepoint_destructors_syms
*tracepoint_destructors_syms_ptr
;
282 struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms
283 __attribute__((weak
, visibility("hidden")));
284 struct lttng_ust_tracepoint_destructors_syms
*tracepoint_destructors_syms_ptr
285 __attribute__((weak
, visibility("hidden")));
287 static inline void tracepoint_disable_destructors(void)
289 if (!tracepoint_dlopen_ptr
)
290 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
291 if (!tracepoint_destructors_syms_ptr
)
292 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
293 if (tracepoint_dlopen_ptr
->liblttngust_handle
294 && tracepoint_destructors_syms_ptr
->tracepoint_disable_destructors
)
295 tracepoint_destructors_syms_ptr
->tracepoint_disable_destructors();
296 *tracepoint_destructors_syms_ptr
->old_tracepoint_disable_destructors
= 1;
300 static inline void lttng_ust_notrace
301 __tracepoint__init_urcu_sym(void);
303 __tracepoint__init_urcu_sym(void)
305 if (!tracepoint_dlopen_ptr
)
306 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
308 * Symbols below are needed by tracepoint call sites and probe
311 if (!tracepoint_dlopen_ptr
->rcu_read_lock_sym_bp
)
312 tracepoint_dlopen_ptr
->rcu_read_lock_sym_bp
=
313 URCU_FORCE_CAST(void (*)(void),
314 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
315 "tp_rcu_read_lock_bp"));
316 if (!tracepoint_dlopen_ptr
->rcu_read_unlock_sym_bp
)
317 tracepoint_dlopen_ptr
->rcu_read_unlock_sym_bp
=
318 URCU_FORCE_CAST(void (*)(void),
319 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
320 "tp_rcu_read_unlock_bp"));
321 if (!tracepoint_dlopen_ptr
->rcu_dereference_sym_bp
)
322 tracepoint_dlopen_ptr
->rcu_dereference_sym_bp
=
323 URCU_FORCE_CAST(void *(*)(void *p
),
324 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
325 "tp_rcu_dereference_sym_bp"));
328 static inline void lttng_ust_notrace
329 __tracepoint__init_urcu_sym(void);
331 __tracepoint__init_urcu_sym(void)
336 static void lttng_ust_notrace
__attribute__((constructor
))
337 __tracepoints__init(void);
339 __tracepoints__init(void)
341 if (__tracepoint_registered
++) {
342 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
344 __tracepoint__init_urcu_sym();
348 if (!tracepoint_dlopen_ptr
)
349 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
350 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
351 tracepoint_dlopen_ptr
->liblttngust_handle
=
352 dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW
| RTLD_GLOBAL
);
353 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
355 __tracepoint__init_urcu_sym();
358 static void lttng_ust_notrace
__attribute__((destructor
))
359 __tracepoints__destroy(void);
361 __tracepoints__destroy(void)
365 if (--__tracepoint_registered
)
367 if (!tracepoint_dlopen_ptr
)
368 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
369 if (!tracepoint_destructors_syms_ptr
)
370 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
371 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
373 if (__tracepoint_ptrs_registered
)
376 * Lookup if destructors must be executed using the new method.
378 if (tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state
379 && !tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state()) {
381 * The tracepoint_get_destructors_state symbol was found with
382 * dlsym but its returned value is 0 meaning that destructors
383 * must not be executed.
388 * Lookup if destructors must be executed using the old method.
390 if (tracepoint_destructors_syms_ptr
->old_tracepoint_disable_destructors
391 && *tracepoint_destructors_syms_ptr
->old_tracepoint_disable_destructors
) {
393 * The old_tracepoint_disable_destructors symbol was found with
394 * dlsym but its value is 1 meaning that destructors must not
400 ret
= dlclose(tracepoint_dlopen_ptr
->liblttngust_handle
);
402 fprintf(stderr
, "Error (%d) in dlclose\n", ret
);
405 memset(tracepoint_dlopen_ptr
, 0, sizeof(*tracepoint_dlopen_ptr
));
408 #ifdef TRACEPOINT_DEFINE
411 * These weak symbols, the constructor, and destructor take care of
412 * registering only _one_ instance of the tracepoints per shared-ojbect
413 * (or for the whole main program).
415 extern struct lttng_ust_tracepoint
* const __start___tracepoints_ptrs
[]
416 __attribute__((weak
, visibility("hidden")));
417 extern struct lttng_ust_tracepoint
* const __stop___tracepoints_ptrs
[]
418 __attribute__((weak
, visibility("hidden")));
421 * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
422 * unresolved symbol that requires the provider to be linked in. When
423 * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
424 * unresolved symbol that depends on having the provider linked in,
425 * otherwise the linker complains. This deals with use of static
426 * libraries, ensuring that the linker does not remove the provider
427 * object from the executable.
429 #ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
430 #define _TRACEPOINT_UNDEFINED_REF(provider) NULL
431 #else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
432 #define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
433 #endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
436 * Note: to allow PIC code, we need to allow the linker to update the pointers
437 * in the __tracepoints_ptrs section.
438 * Therefore, this section is _not_ const (read-only).
440 #define _TP_EXTRACT_STRING(...) #__VA_ARGS__
442 #define _DEFINE_TRACEPOINT(_provider, _name, _args) \
443 extern int __tracepoint_provider_##_provider; \
444 static const char __tp_strtab_##_provider##___##_name[] \
445 __attribute__((section("__tracepoints_strings"))) = \
446 #_provider ":" #_name; \
447 struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name \
448 __attribute__((section("__tracepoints"))) = \
450 __tp_strtab_##_provider##___##_name, \
453 _TRACEPOINT_UNDEFINED_REF(_provider), \
454 _TP_EXTRACT_STRING(_args), \
457 static struct lttng_ust_tracepoint * \
458 __tracepoint_ptr_##_provider##___##_name \
459 __attribute__((section("__tracepoints_ptrs"), used)) \
460 __lttng_ust_variable_attribute_no_sanitize_address = \
461 &__tracepoint_##_provider##___##_name;
463 static void lttng_ust_notrace
__attribute__((constructor
))
464 __tracepoints__ptrs_init(void);
466 __tracepoints__ptrs_init(void)
468 if (__tracepoint_ptrs_registered
++)
470 if (!tracepoint_dlopen_ptr
)
471 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
472 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
473 tracepoint_dlopen_ptr
->liblttngust_handle
=
474 dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW
| RTLD_GLOBAL
);
475 if (!tracepoint_dlopen_ptr
->liblttngust_handle
)
477 if (!tracepoint_destructors_syms_ptr
)
478 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
479 tracepoint_dlopen_ptr
->tracepoint_register_lib
=
480 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint
* const *, int),
481 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
482 "tracepoint_register_lib"));
483 tracepoint_dlopen_ptr
->tracepoint_unregister_lib
=
484 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint
* const *),
485 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
486 "tracepoint_unregister_lib"));
487 tracepoint_destructors_syms_ptr
->old_tracepoint_disable_destructors
=
488 URCU_FORCE_CAST(int *,
489 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
490 "__tracepoints__disable_destructors"));
491 tracepoint_destructors_syms_ptr
->tracepoint_disable_destructors
=
492 URCU_FORCE_CAST(void (*)(void),
493 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
494 "tp_disable_destructors"));
495 tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state
=
496 URCU_FORCE_CAST(int (*)(void),
497 dlsym(tracepoint_dlopen_ptr
->liblttngust_handle
,
498 "tp_get_destructors_state"));
499 __tracepoint__init_urcu_sym();
500 if (tracepoint_dlopen_ptr
->tracepoint_register_lib
) {
501 tracepoint_dlopen_ptr
->tracepoint_register_lib(__start___tracepoints_ptrs
,
502 __stop___tracepoints_ptrs
-
503 __start___tracepoints_ptrs
);
507 static void lttng_ust_notrace
__attribute__((destructor
))
508 __tracepoints__ptrs_destroy(void);
510 __tracepoints__ptrs_destroy(void)
514 if (--__tracepoint_ptrs_registered
)
516 if (!tracepoint_dlopen_ptr
)
517 tracepoint_dlopen_ptr
= &tracepoint_dlopen
;
518 if (!tracepoint_destructors_syms_ptr
)
519 tracepoint_destructors_syms_ptr
= &tracepoint_destructors_syms
;
520 if (tracepoint_dlopen_ptr
->tracepoint_unregister_lib
)
521 tracepoint_dlopen_ptr
->tracepoint_unregister_lib(__start___tracepoints_ptrs
);
522 if (tracepoint_dlopen_ptr
->liblttngust_handle
523 && tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state
524 && tracepoint_destructors_syms_ptr
->tracepoint_get_destructors_state()
525 && !__tracepoint_ptrs_registered
) {
526 ret
= dlclose(tracepoint_dlopen_ptr
->liblttngust_handle
);
528 fprintf(stderr
, "Error (%d) in dlclose\n", ret
);
531 memset(tracepoint_dlopen_ptr
, 0, sizeof(*tracepoint_dlopen_ptr
));
535 #else /* TRACEPOINT_DEFINE */
537 #define _DEFINE_TRACEPOINT(_provider, _name, _args)
539 #endif /* #else TRACEPOINT_DEFINE */
545 #endif /* _LTTNG_TRACEPOINT_H */
547 /* The following declarations must be outside re-inclusion protection. */
549 #ifndef TRACEPOINT_ENUM
552 * Tracepoint Enumerations
554 * The enumeration is a mapping between an integer, or range of integers, and
555 * a string. It can be used to have a more compact trace in cases where the
556 * possible values for a field are limited:
560 * TRACEPOINT_ENUM(someproject_component, enumname,
562 * ctf_enum_value("even", 0)
563 * ctf_enum_value("uneven", 1)
564 * ctf_enum_range("twoto4", 2, 4)
565 * ctf_enum_value("five", 5)
569 * Where "someproject_component" is the name of the component this enumeration
570 * belongs to and "enumname" identifies this enumeration. Inside the
571 * TP_ENUM_VALUES macro is the actual mapping. Each string value can map
572 * to either a single value with ctf_enum_value or a range of values
573 * with ctf_enum_range.
575 * Enumeration ranges may overlap, but the behavior is implementation-defined,
576 * each trace reader will handle overlapping as it wishes.
578 * That enumeration can then be used in a field inside the TP_FIELD macro using
579 * the following line:
581 * ctf_enum(someproject_component, enumname, enumtype, enumfield, enumval)
583 * Where "someproject_component" and "enumname" match those in the
584 * TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
585 * backing the enumeration, "enumfield" is the name of the field and
586 * "enumval" is the value.
589 #define TRACEPOINT_ENUM(provider, name, values)
591 #endif /* #ifndef TRACEPOINT_ENUM */
593 #ifndef TRACEPOINT_EVENT
596 * How to use the TRACEPOINT_EVENT macro:
600 * TRACEPOINT_EVENT(someproject_component, event_name,
602 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
604 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
605 * long *, arg4, size_t, arg4_len),
607 * * TP_FIELDS describes the event payload layout in the trace *
610 * * Integer, printed in base 10 *
611 * ctf_integer(int, field_a, arg0)
613 * * Integer, printed with 0x base 16 *
614 * ctf_integer_hex(unsigned long, field_d, arg1)
617 * ctf_enum(someproject_component, enum_name, int, field_e, arg0)
619 * * Array Sequence, printed as UTF8-encoded array of bytes *
620 * ctf_array_text(char, field_b, string, FIXED_LEN)
621 * ctf_sequence_text(char, field_c, string, size_t, strlen)
623 * * String, printed as UTF8-encoded string *
624 * ctf_string(field_e, string)
626 * * Array sequence of signed integer values *
627 * ctf_array(long, field_f, arg4, FIXED_LEN4)
628 * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
632 * More detailed explanation:
634 * The name of the tracepoint is expressed as a tuple with the provider
635 * and name arguments.
637 * The provider and name should be a proper C99 identifier.
638 * The "provider" and "name" MUST follow these rules to ensure no
639 * namespace clash occurs:
641 * For projects (applications and libraries) for which an entity
642 * specific to the project controls the source code and thus its
643 * tracepoints (typically with a scope larger than a single company):
646 * project_component, event
650 * Where "project" is the name of the project,
651 * "component" is the name of the project component (which may
652 * include several levels of sub-components, e.g.
653 * ...component_subcomponent_...) where the tracepoint is located
655 * "event" is the name of the tracepoint event.
657 * For projects issued from a single company wishing to advertise that
658 * the company controls the source code and thus the tracepoints, the
659 * "com_" prefix should be used:
662 * com_company_project_component, event
664 * com_company_project, event
666 * Where "company" is the name of the company,
667 * "project" is the name of the project,
668 * "component" is the name of the project component (which may
669 * include several levels of sub-components, e.g.
670 * ...component_subcomponent_...) where the tracepoint is located
672 * "event" is the name of the tracepoint event.
674 * the provider:event identifier is limited to 127 characters.
677 #define TRACEPOINT_EVENT(provider, name, args, fields) \
678 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
679 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
681 #define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
683 #define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
684 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
685 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
687 #endif /* #ifndef TRACEPOINT_EVENT */
689 #ifndef TRACEPOINT_LOGLEVEL
692 * Tracepoint Loglevels
694 * Typical use of these loglevels:
696 * The loglevels go from 0 to 14. Higher numbers imply the most
697 * verbosity (higher event throughput expected.
699 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
700 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
707 * action must be taken immediately
710 * critical conditions
719 * normal, but significant, condition
722 * informational message
724 * TRACE_DEBUG_SYSTEM 7
725 * debug information with system-level scope (set of programs)
727 * TRACE_DEBUG_PROGRAM 8
728 * debug information with program-level scope (set of processes)
730 * TRACE_DEBUG_PROCESS 9
731 * debug information with process-level scope (set of modules)
733 * TRACE_DEBUG_MODULE 10
734 * debug information with module (executable/library) scope (set of units)
736 * TRACE_DEBUG_UNIT 11
737 * debug information with compilation unit scope (set of functions)
739 * TRACE_DEBUG_FUNCTION 12
740 * debug information with function-level scope
742 * TRACE_DEBUG_LINE 13
743 * debug information with line-level scope (TRACEPOINT_EVENT default)
746 * debug-level message
748 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
749 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
750 * tracepoint name. The first field is the provider name, the second
751 * field is the name of the tracepoint, the third field is the loglevel
754 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
757 * The TRACEPOINT_PROVIDER must be already declared before declaring a
758 * TRACEPOINT_LOGLEVEL.
769 TRACE_DEBUG_SYSTEM
= 7,
770 TRACE_DEBUG_PROGRAM
= 8,
771 TRACE_DEBUG_PROCESS
= 9,
772 TRACE_DEBUG_MODULE
= 10,
773 TRACE_DEBUG_UNIT
= 11,
774 TRACE_DEBUG_FUNCTION
= 12,
775 TRACE_DEBUG_LINE
= 13,
779 #define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
781 #endif /* #ifndef TRACEPOINT_LOGLEVEL */
783 #ifndef TRACEPOINT_MODEL_EMF_URI
785 #define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
787 #endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */