Fix: add missing tracelog-internal.h to makefile
[lttng-ust.git] / include / lttng / tracepoint.h
1 #ifndef _LTTNG_TRACEPOINT_H
2 #define _LTTNG_TRACEPOINT_H
3
4 /*
5 * Copyright 2011-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 *
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:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
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
23 * SOFTWARE.
24 */
25
26 #include <stdio.h>
27 #include <stdlib.h>
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>
36
37 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
38 /*
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.
42 */
43 #include <sys/sdt.h>
44
45 #define _LTTNG_SDT_NARG(...) \
46 __LTTNG_SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0)
47
48 #define __LTTNG_SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N
49
50 #define _LTTNG_SDT_PROBE_N(provider, name, N, ...) \
51 _SDT_PROBE(provider, name, N, (__VA_ARGS__))
52
53 #define LTTNG_STAP_PROBEV(provider, name, ...) \
54 _LTTNG_SDT_PROBE_N(provider, name, _LTTNG_SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__)
55
56 #else
57 #define LTTNG_STAP_PROBEV(...)
58 #endif
59
60 #ifdef __cplusplus
61 extern "C" {
62 #endif
63
64 #define tracepoint_enabled(provider, name) \
65 caa_unlikely(CMM_LOAD_SHARED(__tracepoint_##provider##___##name.state))
66
67 #define do_tracepoint(provider, name, ...) \
68 __tracepoint_cb_##provider##___##name(__VA_ARGS__)
69
70 #define tracepoint(provider, name, ...) \
71 do { \
72 LTTNG_STAP_PROBEV(provider, name, ## __VA_ARGS__); \
73 if (tracepoint_enabled(provider, name)) \
74 do_tracepoint(provider, name, __VA_ARGS__); \
75 } while (0)
76
77 #define TP_ARGS(...) __VA_ARGS__
78
79 /*
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
82 * fine too).
83 * Each tuple is also separated by a comma.
84 */
85 #define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
86 _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)
97
98 /*
99 * _TP_EXVAR* extract the var names.
100 * _TP_EXVAR1 and _TP_EXDATA_VAR1 are needed for -std=c99.
101 */
102 #define _TP_EXVAR0()
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
114
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
127
128 /*
129 * _TP_EXPROTO* extract tuples of type, var.
130 * _TP_EXPROTO1 and _TP_EXDATA_PROTO1 are needed for -std=c99.
131 */
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
144
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
157
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__
170
171 /*
172 * The tracepoint cb is marked always inline so we can distinguish
173 * between caller's ip addresses within the probe using the return
174 * address.
175 */
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__)); \
180 static \
181 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
182 { \
183 struct lttng_ust_tracepoint_probe *__tp_probe; \
184 \
185 if (caa_unlikely(!TP_RCU_LINK_TEST())) \
186 return; \
187 tp_rcu_read_lock_bp(); \
188 __tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
189 if (caa_unlikely(!__tp_probe)) \
190 goto end; \
191 do { \
192 void (*__tp_cb)(void) = __tp_probe->func; \
193 void *__tp_data = __tp_probe->data; \
194 \
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); \
198 end: \
199 tp_rcu_read_unlock_bp(); \
200 } \
201 static inline lttng_ust_notrace \
202 void __tracepoint_register_##_provider##___##_name(char *name, \
203 void (*func)(void), void *data); \
204 static inline \
205 void __tracepoint_register_##_provider##___##_name(char *name, \
206 void (*func)(void), void *data) \
207 { \
208 __tracepoint_probe_register(name, func, data, \
209 __tracepoint_##_provider##___##_name.signature); \
210 } \
211 static inline lttng_ust_notrace \
212 void __tracepoint_unregister_##_provider##___##_name(char *name, \
213 void (*func)(void), void *data); \
214 static inline \
215 void __tracepoint_unregister_##_provider##___##_name(char *name, \
216 void (*func)(void), void *data) \
217 { \
218 __tracepoint_probe_unregister(name, func, data); \
219 }
220
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),
224 void *data);
225
226 /*
227 * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
228 * shared across objects in a module/main executable.
229 */
230 struct lttng_ust_tracepoint_dlopen {
231 void *liblttngust_handle;
232
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);
239 };
240
241 extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen;
242 extern struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr;
243
244 /*
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).
248 */
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")));
255 /*
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
263 * header.
264 */
265 struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr
266 __attribute__((weak, visibility("hidden")));
267
268 /*
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.
272 */
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);
277 };
278
279 extern struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms;
280 extern struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr;
281
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")));
286
287 static inline void tracepoint_disable_destructors(void)
288 {
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;
297 }
298
299 #ifndef _LGPL_SOURCE
300 static inline void lttng_ust_notrace
301 __tracepoint__init_urcu_sym(void);
302 static inline void
303 __tracepoint__init_urcu_sym(void)
304 {
305 if (!tracepoint_dlopen_ptr)
306 tracepoint_dlopen_ptr = &tracepoint_dlopen;
307 /*
308 * Symbols below are needed by tracepoint call sites and probe
309 * providers.
310 */
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"));
326 }
327 #else
328 static inline void lttng_ust_notrace
329 __tracepoint__init_urcu_sym(void);
330 static inline void
331 __tracepoint__init_urcu_sym(void)
332 {
333 }
334 #endif
335
336 static void lttng_ust_notrace __attribute__((constructor))
337 __tracepoints__init(void);
338 static void
339 __tracepoints__init(void)
340 {
341 if (__tracepoint_registered++) {
342 if (!tracepoint_dlopen_ptr->liblttngust_handle)
343 return;
344 __tracepoint__init_urcu_sym();
345 return;
346 }
347
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)
354 return;
355 __tracepoint__init_urcu_sym();
356 }
357
358 static void lttng_ust_notrace __attribute__((destructor))
359 __tracepoints__destroy(void);
360 static void
361 __tracepoints__destroy(void)
362 {
363 int ret;
364
365 if (--__tracepoint_registered)
366 return;
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)
372 return;
373 if (__tracepoint_ptrs_registered)
374 return;
375 /*
376 * Lookup if destructors must be executed using the new method.
377 */
378 if (tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
379 && !tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()) {
380 /*
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.
384 */
385 return;
386 }
387 /*
388 * Lookup if destructors must be executed using the old method.
389 */
390 if (tracepoint_destructors_syms_ptr->old_tracepoint_disable_destructors
391 && *tracepoint_destructors_syms_ptr->old_tracepoint_disable_destructors) {
392 /*
393 * The old_tracepoint_disable_destructors symbol was found with
394 * dlsym but its value is 1 meaning that destructors must not
395 * be executed.
396 */
397 return;
398 }
399
400 ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
401 if (ret) {
402 fprintf(stderr, "Error (%d) in dlclose\n", ret);
403 abort();
404 }
405 memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
406 }
407
408 #ifdef TRACEPOINT_DEFINE
409
410 /*
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).
414 */
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")));
419
420 /*
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.
428 */
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 */
434
435 /*
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).
439 */
440 #define _TP_EXTRACT_STRING(...) #__VA_ARGS__
441
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"))) = \
449 { \
450 __tp_strtab_##_provider##___##_name, \
451 0, \
452 NULL, \
453 _TRACEPOINT_UNDEFINED_REF(_provider), \
454 _TP_EXTRACT_STRING(_args), \
455 { }, \
456 }; \
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;
462
463 static void lttng_ust_notrace __attribute__((constructor))
464 __tracepoints__ptrs_init(void);
465 static void
466 __tracepoints__ptrs_init(void)
467 {
468 if (__tracepoint_ptrs_registered++)
469 return;
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)
476 return;
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);
504 }
505 }
506
507 static void lttng_ust_notrace __attribute__((destructor))
508 __tracepoints__ptrs_destroy(void);
509 static void
510 __tracepoints__ptrs_destroy(void)
511 {
512 int ret;
513
514 if (--__tracepoint_ptrs_registered)
515 return;
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);
527 if (ret) {
528 fprintf(stderr, "Error (%d) in dlclose\n", ret);
529 abort();
530 }
531 memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
532 }
533 }
534
535 #else /* TRACEPOINT_DEFINE */
536
537 #define _DEFINE_TRACEPOINT(_provider, _name, _args)
538
539 #endif /* #else TRACEPOINT_DEFINE */
540
541 #ifdef __cplusplus
542 }
543 #endif
544
545 #endif /* _LTTNG_TRACEPOINT_H */
546
547 /* The following declarations must be outside re-inclusion protection. */
548
549 #ifndef TRACEPOINT_ENUM
550
551 /*
552 * Tracepoint Enumerations
553 *
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:
557 *
558 * An example:
559 *
560 * TRACEPOINT_ENUM(someproject_component, enumname,
561 * TP_ENUM_VALUES(
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)
566 * )
567 * )
568 *
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.
574 *
575 * Enumeration ranges may overlap, but the behavior is implementation-defined,
576 * each trace reader will handle overlapping as it wishes.
577 *
578 * That enumeration can then be used in a field inside the TP_FIELD macro using
579 * the following line:
580 *
581 * ctf_enum(someproject_component, enumname, enumtype, enumfield, enumval)
582 *
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.
587 */
588
589 #define TRACEPOINT_ENUM(provider, name, values)
590
591 #endif /* #ifndef TRACEPOINT_ENUM */
592
593 #ifndef TRACEPOINT_EVENT
594
595 /*
596 * How to use the TRACEPOINT_EVENT macro:
597 *
598 * An example:
599 *
600 * TRACEPOINT_EVENT(someproject_component, event_name,
601 *
602 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
603 *
604 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
605 * long *, arg4, size_t, arg4_len),
606 *
607 * * TP_FIELDS describes the event payload layout in the trace *
608 *
609 * TP_FIELDS(
610 * * Integer, printed in base 10 *
611 * ctf_integer(int, field_a, arg0)
612 *
613 * * Integer, printed with 0x base 16 *
614 * ctf_integer_hex(unsigned long, field_d, arg1)
615 *
616 * * Enumeration *
617 * ctf_enum(someproject_component, enum_name, int, field_e, arg0)
618 *
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)
622 *
623 * * String, printed as UTF8-encoded string *
624 * ctf_string(field_e, string)
625 *
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)
629 * )
630 * )
631 *
632 * More detailed explanation:
633 *
634 * The name of the tracepoint is expressed as a tuple with the provider
635 * and name arguments.
636 *
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:
640 *
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):
644 *
645 * either:
646 * project_component, event
647 * or:
648 * project, event
649 *
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
654 * (optional),
655 * "event" is the name of the tracepoint event.
656 *
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:
660 *
661 * either:
662 * com_company_project_component, event
663 * or:
664 * com_company_project, event
665 *
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
671 * (optional),
672 * "event" is the name of the tracepoint event.
673 *
674 * the provider:event identifier is limited to 127 characters.
675 */
676
677 #define TRACEPOINT_EVENT(provider, name, args, fields) \
678 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
679 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
680
681 #define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
682
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))
686
687 #endif /* #ifndef TRACEPOINT_EVENT */
688
689 #ifndef TRACEPOINT_LOGLEVEL
690
691 /*
692 * Tracepoint Loglevels
693 *
694 * Typical use of these loglevels:
695 *
696 * The loglevels go from 0 to 14. Higher numbers imply the most
697 * verbosity (higher event throughput expected.
698 *
699 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
700 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
701 * debug information.
702 *
703 * TRACE_EMERG 0
704 * system is unusable
705 *
706 * TRACE_ALERT 1
707 * action must be taken immediately
708 *
709 * TRACE_CRIT 2
710 * critical conditions
711 *
712 * TRACE_ERR 3
713 * error conditions
714 *
715 * TRACE_WARNING 4
716 * warning conditions
717 *
718 * TRACE_NOTICE 5
719 * normal, but significant, condition
720 *
721 * TRACE_INFO 6
722 * informational message
723 *
724 * TRACE_DEBUG_SYSTEM 7
725 * debug information with system-level scope (set of programs)
726 *
727 * TRACE_DEBUG_PROGRAM 8
728 * debug information with program-level scope (set of processes)
729 *
730 * TRACE_DEBUG_PROCESS 9
731 * debug information with process-level scope (set of modules)
732 *
733 * TRACE_DEBUG_MODULE 10
734 * debug information with module (executable/library) scope (set of units)
735 *
736 * TRACE_DEBUG_UNIT 11
737 * debug information with compilation unit scope (set of functions)
738 *
739 * TRACE_DEBUG_FUNCTION 12
740 * debug information with function-level scope
741 *
742 * TRACE_DEBUG_LINE 13
743 * debug information with line-level scope (TRACEPOINT_EVENT default)
744 *
745 * TRACE_DEBUG 14
746 * debug-level message
747 *
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
752 * name.
753 *
754 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
755 * < loglevel_name >)
756 *
757 * The TRACEPOINT_PROVIDER must be already declared before declaring a
758 * TRACEPOINT_LOGLEVEL.
759 */
760
761 enum {
762 TRACE_EMERG = 0,
763 TRACE_ALERT = 1,
764 TRACE_CRIT = 2,
765 TRACE_ERR = 3,
766 TRACE_WARNING = 4,
767 TRACE_NOTICE = 5,
768 TRACE_INFO = 6,
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,
776 TRACE_DEBUG = 14,
777 };
778
779 #define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
780
781 #endif /* #ifndef TRACEPOINT_LOGLEVEL */
782
783 #ifndef TRACEPOINT_MODEL_EMF_URI
784
785 #define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
786
787 #endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */
This page took 0.07415 seconds and 4 git commands to generate.