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Rename LTTNG_TP_EXTERN_C to LTTNG_UST_TP_EXTERN_C
[lttng-ust.git] / include / lttng / tracepoint.h
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1/*
2 * SPDX-License-Identifier: MIT
3 *
4 * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 */
6
7#ifndef _LTTNG_TRACEPOINT_H
8#define _LTTNG_TRACEPOINT_H
9
10#include <stdio.h>
11#include <stdlib.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 */
18
19#include <lttng/ust-config.h> /* for sdt */
20#include <lttng/ust-compiler.h>
21#include <lttng/ust-tracer.h>
22
23#ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
24/*
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.
28 */
29#include <sys/sdt.h>
30
31#define _LTTNG_SDT_NARG(...) \
32 __LTTNG_SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0)
33
34#define __LTTNG_SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N
35
36#define _LTTNG_SDT_PROBE_N(provider, name, N, ...) \
37 _SDT_PROBE(provider, name, N, (__VA_ARGS__))
38
39#define LTTNG_STAP_PROBEV(provider, name, ...) \
40 _LTTNG_SDT_PROBE_N(provider, name, _LTTNG_SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__)
41
42#else
43#define LTTNG_STAP_PROBEV(...)
44#endif
45
46#ifdef __cplusplus
47extern "C" {
48#endif
49
50#define tracepoint_enabled(provider, name) \
51 caa_unlikely(CMM_LOAD_SHARED(__tracepoint_##provider##___##name.state))
52
53#define do_tracepoint(provider, name, ...) \
54 __tracepoint_cb_##provider##___##name(__VA_ARGS__)
55
56#define tracepoint(provider, name, ...) \
57 do { \
58 LTTNG_STAP_PROBEV(provider, name, ## __VA_ARGS__); \
59 if (tracepoint_enabled(provider, name)) \
60 do_tracepoint(provider, name, __VA_ARGS__); \
61 } while (0)
62
63#define TP_ARGS(...) __VA_ARGS__
64
65/*
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
68 * fine too).
69 * Each tuple is also separated by a comma.
70 */
71#define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
72 _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)
83
84/*
85 * _TP_EXVAR* extract the var names.
86 * _TP_EXVAR1 and _TP_EXDATA_VAR1 are needed for -std=c99.
87 */
88#define _TP_EXVAR0()
89#define _TP_EXVAR1(a)
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
100
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
113
114/*
115 * _TP_EXPROTO* extract tuples of type, var.
116 * _TP_EXPROTO1 and _TP_EXDATA_PROTO1 are needed for -std=c99.
117 */
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
130
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
143
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__
156
157/*
158 * The tracepoint cb is marked always inline so we can distinguish
159 * between caller's ip addresses within the probe using the return
160 * address.
161 */
162#define _DECLARE_TRACEPOINT(_provider, _name, ...) \
163extern struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name; \
164static inline \
165void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
166 __attribute__((always_inline, unused)) lttng_ust_notrace; \
167static \
168void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
169{ \
170 struct lttng_ust_tracepoint_probe *__tp_probe; \
171 \
172 if (caa_unlikely(!TP_RCU_LINK_TEST())) \
173 return; \
174 tp_rcu_read_lock(); \
175 __tp_probe = tp_rcu_dereference(__tracepoint_##_provider##___##_name.probes); \
176 if (caa_unlikely(!__tp_probe)) \
177 goto end; \
178 do { \
179 void (*__tp_cb)(void) = __tp_probe->func; \
180 void *__tp_data = __tp_probe->data; \
181 \
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); \
185end: \
186 tp_rcu_read_unlock(); \
187} \
188static inline \
189void __tracepoint_register_##_provider##___##_name(char *name, \
190 void (*func)(void), void *data) \
191 lttng_ust_notrace; \
192static inline \
193void __tracepoint_register_##_provider##___##_name(char *name, \
194 void (*func)(void), void *data) \
195{ \
196 __tracepoint_probe_register(name, func, data, \
197 __tracepoint_##_provider##___##_name.signature); \
198} \
199static inline \
200void __tracepoint_unregister_##_provider##___##_name(char *name, \
201 void (*func)(void), void *data) \
202 lttng_ust_notrace; \
203static inline \
204void __tracepoint_unregister_##_provider##___##_name(char *name, \
205 void (*func)(void), void *data) \
206{ \
207 __tracepoint_probe_unregister(name, func, data); \
208}
209
210extern int __tracepoint_probe_register(const char *name, void (*func)(void),
211 void *data, const char *signature);
212extern int __tracepoint_probe_unregister(const char *name, void (*func)(void),
213 void *data);
214
215/*
216 * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
217 * shared across objects in a module/main executable.
218 *
219 * IMPORTANT: this structure is part of the ABI between instrumented
220 * applications and UST. Fields need to be only added at the end, never
221 * reordered, never removed.
222 *
223 * The field @struct_size should be used to determine the size of the
224 * structure. It should be queried before using additional fields added
225 * at the end of the structure.
226 */
227struct lttng_ust_tracepoint_dlopen {
228 uint32_t struct_size;
229
230 void *liblttngust_handle;
231
232 int (*tracepoint_register_lib)(struct lttng_ust_tracepoint * const *tracepoints_start,
233 int tracepoints_count);
234 int (*tracepoint_unregister_lib)(struct lttng_ust_tracepoint * const *tracepoints_start);
235 void (*rcu_read_lock_sym)(void);
236 void (*rcu_read_unlock_sym)(void);
237 void *(*rcu_dereference_sym)(void *p);
238
239 /* End of base ABI. Fields below should be used after checking struct_size. */
240};
241
242extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen;
243extern struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr;
244
245/*
246 * These weak symbols, the constructor, and destructor take care of
247 * registering only _one_ instance of the tracepoints per shared-ojbect
248 * (or for the whole main program).
249 */
250int __tracepoint_registered
251 __attribute__((weak, visibility("hidden")));
252int __tracepoint_ptrs_registered
253 __attribute__((weak, visibility("hidden")));
254struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
255 __attribute__((weak, visibility("hidden"))) = {
256 .struct_size = sizeof(struct lttng_ust_tracepoint_dlopen),
257};
258/*
259 * Deal with gcc O1 optimisation issues with weak hidden symbols. gcc
260 * 4.8 and prior does not have the same behavior for symbol scoping on
261 * 32-bit powerpc depending on the object size: symbols for objects of 8
262 * bytes or less have the same address throughout a module, whereas they
263 * have different addresses between compile units for objects larger
264 * than 8 bytes. Add this pointer indirection to ensure that the symbol
265 * scoping match that of the other weak hidden symbols found in this
266 * header.
267 */
268struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr
269 __attribute__((weak, visibility("hidden")));
270
271/*
272 * Tracepoint dynamic linkage handling (callbacks). Hidden visibility: shared
273 * across objects in a module/main executable. The callbacks are used to
274 * control and check if the destructors should be executed.
275 *
276 * IMPORTANT: this structure is part of the ABI between instrumented
277 * applications and UST. Fields need to be only added at the end, never
278 * reordered, never removed.
279 *
280 * The field @struct_size should be used to determine the size of the
281 * structure. It should be queried before using additional fields added
282 * at the end of the structure.
283 */
284struct lttng_ust_tracepoint_destructors_syms {
285 uint32_t struct_size;
286
287 void (*tracepoint_disable_destructors)(void);
288 int (*tracepoint_get_destructors_state)(void);
289
290 /* End of base ABI. Fields below should be used after checking struct_size. */
291};
292
293extern struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms;
294extern struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr;
295
296struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms
297 __attribute__((weak, visibility("hidden"))) = {
298 .struct_size = sizeof(struct lttng_ust_tracepoint_destructors_syms),
299};
300struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr
301 __attribute__((weak, visibility("hidden")));
302
303static inline void tracepoint_disable_destructors(void)
304{
305 if (!tracepoint_dlopen_ptr)
306 tracepoint_dlopen_ptr = &tracepoint_dlopen;
307 if (!tracepoint_destructors_syms_ptr)
308 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
309 if (tracepoint_dlopen_ptr->liblttngust_handle
310 && tracepoint_destructors_syms_ptr->tracepoint_disable_destructors)
311 tracepoint_destructors_syms_ptr->tracepoint_disable_destructors();
312}
313
314#ifndef _LGPL_SOURCE
315static inline void
316__tracepoint__init_urcu_sym(void)
317 lttng_ust_notrace;
318static inline void
319__tracepoint__init_urcu_sym(void)
320{
321 if (!tracepoint_dlopen_ptr)
322 tracepoint_dlopen_ptr = &tracepoint_dlopen;
323 /*
324 * Symbols below are needed by tracepoint call sites and probe
325 * providers.
326 */
327 if (!tracepoint_dlopen_ptr->rcu_read_lock_sym)
328 tracepoint_dlopen_ptr->rcu_read_lock_sym =
329 URCU_FORCE_CAST(void (*)(void),
330 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
331 "tp_rcu_read_lock"));
332 if (!tracepoint_dlopen_ptr->rcu_read_unlock_sym)
333 tracepoint_dlopen_ptr->rcu_read_unlock_sym =
334 URCU_FORCE_CAST(void (*)(void),
335 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
336 "tp_rcu_read_unlock"));
337 if (!tracepoint_dlopen_ptr->rcu_dereference_sym)
338 tracepoint_dlopen_ptr->rcu_dereference_sym =
339 URCU_FORCE_CAST(void *(*)(void *p),
340 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
341 "tp_rcu_dereference_sym"));
342}
343#else
344static inline void
345__tracepoint__init_urcu_sym(void)
346 lttng_ust_notrace;
347static inline void
348__tracepoint__init_urcu_sym(void)
349{
350}
351#endif
352
353static void
354__tracepoints__init(void)
355 lttng_ust_notrace __attribute__((constructor));
356static void
357__tracepoints__init(void)
358{
359 if (__tracepoint_registered++) {
360 if (!tracepoint_dlopen_ptr->liblttngust_handle)
361 return;
362 __tracepoint__init_urcu_sym();
363 return;
364 }
365
366 if (!tracepoint_dlopen_ptr)
367 tracepoint_dlopen_ptr = &tracepoint_dlopen;
368 if (!tracepoint_dlopen_ptr->liblttngust_handle)
369 tracepoint_dlopen_ptr->liblttngust_handle =
370 dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
371 if (!tracepoint_dlopen_ptr->liblttngust_handle)
372 return;
373 __tracepoint__init_urcu_sym();
374}
375
376static void
377__tracepoints__destroy(void)
378 lttng_ust_notrace __attribute__((destructor));
379static void
380__tracepoints__destroy(void)
381{
382 int ret;
383
384 if (--__tracepoint_registered)
385 return;
386 if (!tracepoint_dlopen_ptr)
387 tracepoint_dlopen_ptr = &tracepoint_dlopen;
388 if (!tracepoint_destructors_syms_ptr)
389 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
390 if (!tracepoint_dlopen_ptr->liblttngust_handle)
391 return;
392 if (__tracepoint_ptrs_registered)
393 return;
394 /*
395 * Lookup if destructors must be executed using the new method.
396 */
397 if (tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
398 && !tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()) {
399 /*
400 * The tracepoint_get_destructors_state symbol was found with
401 * dlsym but its returned value is 0 meaning that destructors
402 * must not be executed.
403 */
404 return;
405 }
406 ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
407 if (ret) {
408 fprintf(stderr, "Error (%d) in dlclose\n", ret);
409 abort();
410 }
411 memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
412}
413
414#ifdef TRACEPOINT_DEFINE
415
416/*
417 * These weak symbols, the constructor, and destructor take care of
418 * registering only _one_ instance of the tracepoints per shared-ojbect
419 * (or for the whole main program).
420 */
421extern struct lttng_ust_tracepoint * const __start___tracepoints_ptrs[]
422 __attribute__((weak, visibility("hidden")));
423extern struct lttng_ust_tracepoint * const __stop___tracepoints_ptrs[]
424 __attribute__((weak, visibility("hidden")));
425
426/*
427 * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
428 * unresolved symbol that requires the provider to be linked in. When
429 * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
430 * unresolved symbol that depends on having the provider linked in,
431 * otherwise the linker complains. This deals with use of static
432 * libraries, ensuring that the linker does not remove the provider
433 * object from the executable.
434 */
435#ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
436#define _TRACEPOINT_UNDEFINED_REF(provider) NULL
437#else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
438#define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
439#endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
440
441/*
442 * Note: to allow PIC code, we need to allow the linker to update the pointers
443 * in the __tracepoints_ptrs section.
444 * Therefore, this section is _not_ const (read-only).
445 */
446#define _TP_EXTRACT_STRING(...) #__VA_ARGS__
447
448#define _DEFINE_TRACEPOINT(_provider, _name, _args) \
449 extern int __tracepoint_provider_##_provider; \
450 static const char __tp_strtab_##_provider##___##_name[] \
451 __attribute__((section("__tracepoints_strings"))) = \
452 #_provider ":" #_name; \
453 struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name \
454 __attribute__((section("__tracepoints"))) = { \
455 sizeof(struct lttng_ust_tracepoint), \
456 __tp_strtab_##_provider##___##_name, \
457 0, \
458 NULL, \
459 _TRACEPOINT_UNDEFINED_REF(_provider), \
460 _TP_EXTRACT_STRING(_args), \
461 }; \
462 static struct lttng_ust_tracepoint * \
463 __tracepoint_ptr_##_provider##___##_name \
464 __attribute__((section("__tracepoints_ptrs"), used)) \
465 __lttng_ust_variable_attribute_no_sanitize_address = \
466 &__tracepoint_##_provider##___##_name;
467
468static void
469__tracepoints__ptrs_init(void)
470 lttng_ust_notrace __attribute__((constructor));
471static void
472__tracepoints__ptrs_init(void)
473{
474 if (__tracepoint_ptrs_registered++)
475 return;
476 if (!tracepoint_dlopen_ptr)
477 tracepoint_dlopen_ptr = &tracepoint_dlopen;
478 if (!tracepoint_dlopen_ptr->liblttngust_handle)
479 tracepoint_dlopen_ptr->liblttngust_handle =
480 dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
481 if (!tracepoint_dlopen_ptr->liblttngust_handle)
482 return;
483 if (!tracepoint_destructors_syms_ptr)
484 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
485 tracepoint_dlopen_ptr->tracepoint_register_lib =
486 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int),
487 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
488 "tracepoint_register_lib"));
489 tracepoint_dlopen_ptr->tracepoint_unregister_lib =
490 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *),
491 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
492 "tracepoint_unregister_lib"));
493 tracepoint_destructors_syms_ptr->tracepoint_disable_destructors =
494 URCU_FORCE_CAST(void (*)(void),
495 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
496 "tp_disable_destructors"));
497 tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state =
498 URCU_FORCE_CAST(int (*)(void),
499 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
500 "tp_get_destructors_state"));
501 __tracepoint__init_urcu_sym();
502 if (tracepoint_dlopen_ptr->tracepoint_register_lib) {
503 tracepoint_dlopen_ptr->tracepoint_register_lib(__start___tracepoints_ptrs,
504 __stop___tracepoints_ptrs -
505 __start___tracepoints_ptrs);
506 }
507}
508
509static void
510__tracepoints__ptrs_destroy(void)
511 lttng_ust_notrace __attribute__((destructor));
512static void
513__tracepoints__ptrs_destroy(void)
514{
515 int ret;
516
517 if (--__tracepoint_ptrs_registered)
518 return;
519 if (!tracepoint_dlopen_ptr)
520 tracepoint_dlopen_ptr = &tracepoint_dlopen;
521 if (!tracepoint_destructors_syms_ptr)
522 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
523 if (tracepoint_dlopen_ptr->tracepoint_unregister_lib)
524 tracepoint_dlopen_ptr->tracepoint_unregister_lib(__start___tracepoints_ptrs);
525 if (tracepoint_dlopen_ptr->liblttngust_handle
526 && tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
527 && tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()
528 && !__tracepoint_ptrs_registered) {
529 ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
530 if (ret) {
531 fprintf(stderr, "Error (%d) in dlclose\n", ret);
532 abort();
533 }
534 memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
535 }
536}
537
538#else /* TRACEPOINT_DEFINE */
539
540#define _DEFINE_TRACEPOINT(_provider, _name, _args)
541
542#endif /* #else TRACEPOINT_DEFINE */
543
544#ifdef __cplusplus
545}
546#endif
547
548#endif /* _LTTNG_TRACEPOINT_H */
549
550/* The following declarations must be outside re-inclusion protection. */
551
552#ifndef TRACEPOINT_ENUM
553
554/*
555 * Tracepoint Enumerations
556 *
557 * The enumeration is a mapping between an integer, or range of integers, and
558 * a string. It can be used to have a more compact trace in cases where the
559 * possible values for a field are limited:
560 *
561 * An example:
562 *
563 * TRACEPOINT_ENUM(someproject_component, enumname,
564 * TP_ENUM_VALUES(
565 * ctf_enum_value("even", 0)
566 * ctf_enum_value("uneven", 1)
567 * ctf_enum_range("twoto4", 2, 4)
568 * ctf_enum_value("five", 5)
569 * )
570 * )
571 *
572 * Where "someproject_component" is the name of the component this enumeration
573 * belongs to and "enumname" identifies this enumeration. Inside the
574 * TP_ENUM_VALUES macro is the actual mapping. Each string value can map
575 * to either a single value with ctf_enum_value or a range of values
576 * with ctf_enum_range.
577 *
578 * Enumeration ranges may overlap, but the behavior is implementation-defined,
579 * each trace reader will handle overlapping as it wishes.
580 *
581 * That enumeration can then be used in a field inside the TP_FIELD macro using
582 * the following line:
583 *
584 * ctf_enum(someproject_component, enumname, enumtype, enumfield, enumval)
585 *
586 * Where "someproject_component" and "enumname" match those in the
587 * TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
588 * backing the enumeration, "enumfield" is the name of the field and
589 * "enumval" is the value.
590 */
591
592#define TRACEPOINT_ENUM(provider, name, values)
593
594#endif /* #ifndef TRACEPOINT_ENUM */
595
596#ifndef TRACEPOINT_EVENT
597
598/*
599 * How to use the TRACEPOINT_EVENT macro:
600 *
601 * An example:
602 *
603 * TRACEPOINT_EVENT(someproject_component, event_name,
604 *
605 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
606 *
607 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
608 * long *, arg4, size_t, arg4_len),
609 *
610 * * TP_FIELDS describes the event payload layout in the trace *
611 *
612 * TP_FIELDS(
613 * * Integer, printed in base 10 *
614 * ctf_integer(int, field_a, arg0)
615 *
616 * * Integer, printed with 0x base 16 *
617 * ctf_integer_hex(unsigned long, field_d, arg1)
618 *
619 * * Enumeration *
620 * ctf_enum(someproject_component, enum_name, int, field_e, arg0)
621 *
622 * * Array Sequence, printed as UTF8-encoded array of bytes *
623 * ctf_array_text(char, field_b, string, FIXED_LEN)
624 * ctf_sequence_text(char, field_c, string, size_t, strlen)
625 *
626 * * String, printed as UTF8-encoded string *
627 * ctf_string(field_e, string)
628 *
629 * * Array sequence of signed integer values *
630 * ctf_array(long, field_f, arg4, FIXED_LEN4)
631 * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
632 * )
633 * )
634 *
635 * More detailed explanation:
636 *
637 * The name of the tracepoint is expressed as a tuple with the provider
638 * and name arguments.
639 *
640 * The provider and name should be a proper C99 identifier.
641 * The "provider" and "name" MUST follow these rules to ensure no
642 * namespace clash occurs:
643 *
644 * For projects (applications and libraries) for which an entity
645 * specific to the project controls the source code and thus its
646 * tracepoints (typically with a scope larger than a single company):
647 *
648 * either:
649 * project_component, event
650 * or:
651 * project, event
652 *
653 * Where "project" is the name of the project,
654 * "component" is the name of the project component (which may
655 * include several levels of sub-components, e.g.
656 * ...component_subcomponent_...) where the tracepoint is located
657 * (optional),
658 * "event" is the name of the tracepoint event.
659 *
660 * For projects issued from a single company wishing to advertise that
661 * the company controls the source code and thus the tracepoints, the
662 * "com_" prefix should be used:
663 *
664 * either:
665 * com_company_project_component, event
666 * or:
667 * com_company_project, event
668 *
669 * Where "company" is the name of the company,
670 * "project" is the name of the project,
671 * "component" is the name of the project component (which may
672 * include several levels of sub-components, e.g.
673 * ...component_subcomponent_...) where the tracepoint is located
674 * (optional),
675 * "event" is the name of the tracepoint event.
676 *
677 * the provider:event identifier is limited to 127 characters.
678 */
679
680#define TRACEPOINT_EVENT(provider, name, args, fields) \
681 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
682 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
683
684#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
685
686#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
687 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
688 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
689
690#endif /* #ifndef TRACEPOINT_EVENT */
691
692#ifndef TRACEPOINT_LOGLEVEL
693
694/*
695 * Tracepoint Loglevels
696 *
697 * Typical use of these loglevels:
698 *
699 * The loglevels go from 0 to 14. Higher numbers imply the most
700 * verbosity (higher event throughput expected.
701 *
702 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
703 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
704 * debug information.
705 *
706 * TRACE_EMERG 0
707 * system is unusable
708 *
709 * TRACE_ALERT 1
710 * action must be taken immediately
711 *
712 * TRACE_CRIT 2
713 * critical conditions
714 *
715 * TRACE_ERR 3
716 * error conditions
717 *
718 * TRACE_WARNING 4
719 * warning conditions
720 *
721 * TRACE_NOTICE 5
722 * normal, but significant, condition
723 *
724 * TRACE_INFO 6
725 * informational message
726 *
727 * TRACE_DEBUG_SYSTEM 7
728 * debug information with system-level scope (set of programs)
729 *
730 * TRACE_DEBUG_PROGRAM 8
731 * debug information with program-level scope (set of processes)
732 *
733 * TRACE_DEBUG_PROCESS 9
734 * debug information with process-level scope (set of modules)
735 *
736 * TRACE_DEBUG_MODULE 10
737 * debug information with module (executable/library) scope (set of units)
738 *
739 * TRACE_DEBUG_UNIT 11
740 * debug information with compilation unit scope (set of functions)
741 *
742 * TRACE_DEBUG_FUNCTION 12
743 * debug information with function-level scope
744 *
745 * TRACE_DEBUG_LINE 13
746 * debug information with line-level scope (TRACEPOINT_EVENT default)
747 *
748 * TRACE_DEBUG 14
749 * debug-level message
750 *
751 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
752 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
753 * tracepoint name. The first field is the provider name, the second
754 * field is the name of the tracepoint, the third field is the loglevel
755 * name.
756 *
757 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
758 * < loglevel_name >)
759 *
760 * The TRACEPOINT_PROVIDER must be already declared before declaring a
761 * TRACEPOINT_LOGLEVEL.
762 */
763
764enum {
765 TRACE_EMERG = 0,
766 TRACE_ALERT = 1,
767 TRACE_CRIT = 2,
768 TRACE_ERR = 3,
769 TRACE_WARNING = 4,
770 TRACE_NOTICE = 5,
771 TRACE_INFO = 6,
772 TRACE_DEBUG_SYSTEM = 7,
773 TRACE_DEBUG_PROGRAM = 8,
774 TRACE_DEBUG_PROCESS = 9,
775 TRACE_DEBUG_MODULE = 10,
776 TRACE_DEBUG_UNIT = 11,
777 TRACE_DEBUG_FUNCTION = 12,
778 TRACE_DEBUG_LINE = 13,
779 TRACE_DEBUG = 14,
780};
781
782#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
783
784#endif /* #ifndef TRACEPOINT_LOGLEVEL */
785
786#ifndef TRACEPOINT_MODEL_EMF_URI
787
788#define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
789
790#endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */
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