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cleanup: function attribute 'unused'
[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 lttng_ust_notrace \
189void __tracepoint_register_##_provider##___##_name(char *name, \
190 void (*func)(void), void *data); \
191static inline \
192void __tracepoint_register_##_provider##___##_name(char *name, \
193 void (*func)(void), void *data) \
194{ \
195 __tracepoint_probe_register(name, func, data, \
196 __tracepoint_##_provider##___##_name.signature); \
197} \
198static inline lttng_ust_notrace \
199void __tracepoint_unregister_##_provider##___##_name(char *name, \
200 void (*func)(void), void *data); \
201static inline \
202void __tracepoint_unregister_##_provider##___##_name(char *name, \
203 void (*func)(void), void *data) \
204{ \
205 __tracepoint_probe_unregister(name, func, data); \
206}
207
208extern int __tracepoint_probe_register(const char *name, void (*func)(void),
209 void *data, const char *signature);
210extern int __tracepoint_probe_unregister(const char *name, void (*func)(void),
211 void *data);
212
213/*
214 * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
215 * shared across objects in a module/main executable.
216 *
217 * IMPORTANT: this structure is part of the ABI between instrumented
218 * applications and UST. Fields need to be only added at the end, never
219 * reordered, never removed.
220 *
221 * The field @struct_size should be used to determine the size of the
222 * structure. It should be queried before using additional fields added
223 * at the end of the structure.
224 */
225struct lttng_ust_tracepoint_dlopen {
226 uint32_t struct_size;
227
228 void *liblttngust_handle;
229
230 int (*tracepoint_register_lib)(struct lttng_ust_tracepoint * const *tracepoints_start,
231 int tracepoints_count);
232 int (*tracepoint_unregister_lib)(struct lttng_ust_tracepoint * const *tracepoints_start);
233 void (*rcu_read_lock_sym)(void);
234 void (*rcu_read_unlock_sym)(void);
235 void *(*rcu_dereference_sym)(void *p);
236
237 /* End of base ABI. Fields below should be used after checking struct_size. */
238};
239
240extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen;
241extern struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr;
242
243/*
244 * These weak symbols, the constructor, and destructor take care of
245 * registering only _one_ instance of the tracepoints per shared-ojbect
246 * (or for the whole main program).
247 */
248int __tracepoint_registered
249 __attribute__((weak, visibility("hidden")));
250int __tracepoint_ptrs_registered
251 __attribute__((weak, visibility("hidden")));
252struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
253 __attribute__((weak, visibility("hidden"))) = {
254 .struct_size = sizeof(struct lttng_ust_tracepoint_dlopen),
255};
256/*
257 * Deal with gcc O1 optimisation issues with weak hidden symbols. gcc
258 * 4.8 and prior does not have the same behavior for symbol scoping on
259 * 32-bit powerpc depending on the object size: symbols for objects of 8
260 * bytes or less have the same address throughout a module, whereas they
261 * have different addresses between compile units for objects larger
262 * than 8 bytes. Add this pointer indirection to ensure that the symbol
263 * scoping match that of the other weak hidden symbols found in this
264 * header.
265 */
266struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr
267 __attribute__((weak, visibility("hidden")));
268
269/*
270 * Tracepoint dynamic linkage handling (callbacks). Hidden visibility: shared
271 * across objects in a module/main executable. The callbacks are used to
272 * control and check if the destructors should be executed.
273 *
274 * IMPORTANT: this structure is part of the ABI between instrumented
275 * applications and UST. Fields need to be only added at the end, never
276 * reordered, never removed.
277 *
278 * The field @struct_size should be used to determine the size of the
279 * structure. It should be queried before using additional fields added
280 * at the end of the structure.
281 */
282struct lttng_ust_tracepoint_destructors_syms {
283 uint32_t struct_size;
284
285 void (*tracepoint_disable_destructors)(void);
286 int (*tracepoint_get_destructors_state)(void);
287
288 /* End of base ABI. Fields below should be used after checking struct_size. */
289};
290
291extern struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms;
292extern struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr;
293
294struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms
295 __attribute__((weak, visibility("hidden"))) = {
296 .struct_size = sizeof(struct lttng_ust_tracepoint_destructors_syms),
297};
298struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr
299 __attribute__((weak, visibility("hidden")));
300
301static inline void tracepoint_disable_destructors(void)
302{
303 if (!tracepoint_dlopen_ptr)
304 tracepoint_dlopen_ptr = &tracepoint_dlopen;
305 if (!tracepoint_destructors_syms_ptr)
306 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
307 if (tracepoint_dlopen_ptr->liblttngust_handle
308 && tracepoint_destructors_syms_ptr->tracepoint_disable_destructors)
309 tracepoint_destructors_syms_ptr->tracepoint_disable_destructors();
310}
311
312#ifndef _LGPL_SOURCE
313static inline void lttng_ust_notrace
314__tracepoint__init_urcu_sym(void);
315static inline void
316__tracepoint__init_urcu_sym(void)
317{
318 if (!tracepoint_dlopen_ptr)
319 tracepoint_dlopen_ptr = &tracepoint_dlopen;
320 /*
321 * Symbols below are needed by tracepoint call sites and probe
322 * providers.
323 */
324 if (!tracepoint_dlopen_ptr->rcu_read_lock_sym)
325 tracepoint_dlopen_ptr->rcu_read_lock_sym =
326 URCU_FORCE_CAST(void (*)(void),
327 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
328 "tp_rcu_read_lock"));
329 if (!tracepoint_dlopen_ptr->rcu_read_unlock_sym)
330 tracepoint_dlopen_ptr->rcu_read_unlock_sym =
331 URCU_FORCE_CAST(void (*)(void),
332 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
333 "tp_rcu_read_unlock"));
334 if (!tracepoint_dlopen_ptr->rcu_dereference_sym)
335 tracepoint_dlopen_ptr->rcu_dereference_sym =
336 URCU_FORCE_CAST(void *(*)(void *p),
337 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
338 "tp_rcu_dereference_sym"));
339}
340#else
341static inline void lttng_ust_notrace
342__tracepoint__init_urcu_sym(void);
343static inline void
344__tracepoint__init_urcu_sym(void)
345{
346}
347#endif
348
349static void lttng_ust_notrace __attribute__((constructor))
350__tracepoints__init(void);
351static void
352__tracepoints__init(void)
353{
354 if (__tracepoint_registered++) {
355 if (!tracepoint_dlopen_ptr->liblttngust_handle)
356 return;
357 __tracepoint__init_urcu_sym();
358 return;
359 }
360
361 if (!tracepoint_dlopen_ptr)
362 tracepoint_dlopen_ptr = &tracepoint_dlopen;
363 if (!tracepoint_dlopen_ptr->liblttngust_handle)
364 tracepoint_dlopen_ptr->liblttngust_handle =
365 dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
366 if (!tracepoint_dlopen_ptr->liblttngust_handle)
367 return;
368 __tracepoint__init_urcu_sym();
369}
370
371static void lttng_ust_notrace __attribute__((destructor))
372__tracepoints__destroy(void);
373static void
374__tracepoints__destroy(void)
375{
376 int ret;
377
378 if (--__tracepoint_registered)
379 return;
380 if (!tracepoint_dlopen_ptr)
381 tracepoint_dlopen_ptr = &tracepoint_dlopen;
382 if (!tracepoint_destructors_syms_ptr)
383 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
384 if (!tracepoint_dlopen_ptr->liblttngust_handle)
385 return;
386 if (__tracepoint_ptrs_registered)
387 return;
388 /*
389 * Lookup if destructors must be executed using the new method.
390 */
391 if (tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
392 && !tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()) {
393 /*
394 * The tracepoint_get_destructors_state symbol was found with
395 * dlsym but its returned value is 0 meaning that destructors
396 * must not be executed.
397 */
398 return;
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 */
415extern struct lttng_ust_tracepoint * const __start___tracepoints_ptrs[]
416 __attribute__((weak, visibility("hidden")));
417extern 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 sizeof(struct lttng_ust_tracepoint), \
450 __tp_strtab_##_provider##___##_name, \
451 0, \
452 NULL, \
453 _TRACEPOINT_UNDEFINED_REF(_provider), \
454 _TP_EXTRACT_STRING(_args), \
455 }; \
456 static struct lttng_ust_tracepoint * \
457 __tracepoint_ptr_##_provider##___##_name \
458 __attribute__((section("__tracepoints_ptrs"), used)) \
459 __lttng_ust_variable_attribute_no_sanitize_address = \
460 &__tracepoint_##_provider##___##_name;
461
462static void lttng_ust_notrace __attribute__((constructor))
463__tracepoints__ptrs_init(void);
464static void
465__tracepoints__ptrs_init(void)
466{
467 if (__tracepoint_ptrs_registered++)
468 return;
469 if (!tracepoint_dlopen_ptr)
470 tracepoint_dlopen_ptr = &tracepoint_dlopen;
471 if (!tracepoint_dlopen_ptr->liblttngust_handle)
472 tracepoint_dlopen_ptr->liblttngust_handle =
473 dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
474 if (!tracepoint_dlopen_ptr->liblttngust_handle)
475 return;
476 if (!tracepoint_destructors_syms_ptr)
477 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
478 tracepoint_dlopen_ptr->tracepoint_register_lib =
479 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int),
480 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
481 "tracepoint_register_lib"));
482 tracepoint_dlopen_ptr->tracepoint_unregister_lib =
483 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *),
484 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
485 "tracepoint_unregister_lib"));
486 tracepoint_destructors_syms_ptr->tracepoint_disable_destructors =
487 URCU_FORCE_CAST(void (*)(void),
488 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
489 "tp_disable_destructors"));
490 tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state =
491 URCU_FORCE_CAST(int (*)(void),
492 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
493 "tp_get_destructors_state"));
494 __tracepoint__init_urcu_sym();
495 if (tracepoint_dlopen_ptr->tracepoint_register_lib) {
496 tracepoint_dlopen_ptr->tracepoint_register_lib(__start___tracepoints_ptrs,
497 __stop___tracepoints_ptrs -
498 __start___tracepoints_ptrs);
499 }
500}
501
502static void lttng_ust_notrace __attribute__((destructor))
503__tracepoints__ptrs_destroy(void);
504static void
505__tracepoints__ptrs_destroy(void)
506{
507 int ret;
508
509 if (--__tracepoint_ptrs_registered)
510 return;
511 if (!tracepoint_dlopen_ptr)
512 tracepoint_dlopen_ptr = &tracepoint_dlopen;
513 if (!tracepoint_destructors_syms_ptr)
514 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
515 if (tracepoint_dlopen_ptr->tracepoint_unregister_lib)
516 tracepoint_dlopen_ptr->tracepoint_unregister_lib(__start___tracepoints_ptrs);
517 if (tracepoint_dlopen_ptr->liblttngust_handle
518 && tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
519 && tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()
520 && !__tracepoint_ptrs_registered) {
521 ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
522 if (ret) {
523 fprintf(stderr, "Error (%d) in dlclose\n", ret);
524 abort();
525 }
526 memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
527 }
528}
529
530#else /* TRACEPOINT_DEFINE */
531
532#define _DEFINE_TRACEPOINT(_provider, _name, _args)
533
534#endif /* #else TRACEPOINT_DEFINE */
535
536#ifdef __cplusplus
537}
538#endif
539
540#endif /* _LTTNG_TRACEPOINT_H */
541
542/* The following declarations must be outside re-inclusion protection. */
543
544#ifndef TRACEPOINT_ENUM
545
546/*
547 * Tracepoint Enumerations
548 *
549 * The enumeration is a mapping between an integer, or range of integers, and
550 * a string. It can be used to have a more compact trace in cases where the
551 * possible values for a field are limited:
552 *
553 * An example:
554 *
555 * TRACEPOINT_ENUM(someproject_component, enumname,
556 * TP_ENUM_VALUES(
557 * ctf_enum_value("even", 0)
558 * ctf_enum_value("uneven", 1)
559 * ctf_enum_range("twoto4", 2, 4)
560 * ctf_enum_value("five", 5)
561 * )
562 * )
563 *
564 * Where "someproject_component" is the name of the component this enumeration
565 * belongs to and "enumname" identifies this enumeration. Inside the
566 * TP_ENUM_VALUES macro is the actual mapping. Each string value can map
567 * to either a single value with ctf_enum_value or a range of values
568 * with ctf_enum_range.
569 *
570 * Enumeration ranges may overlap, but the behavior is implementation-defined,
571 * each trace reader will handle overlapping as it wishes.
572 *
573 * That enumeration can then be used in a field inside the TP_FIELD macro using
574 * the following line:
575 *
576 * ctf_enum(someproject_component, enumname, enumtype, enumfield, enumval)
577 *
578 * Where "someproject_component" and "enumname" match those in the
579 * TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
580 * backing the enumeration, "enumfield" is the name of the field and
581 * "enumval" is the value.
582 */
583
584#define TRACEPOINT_ENUM(provider, name, values)
585
586#endif /* #ifndef TRACEPOINT_ENUM */
587
588#ifndef TRACEPOINT_EVENT
589
590/*
591 * How to use the TRACEPOINT_EVENT macro:
592 *
593 * An example:
594 *
595 * TRACEPOINT_EVENT(someproject_component, event_name,
596 *
597 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
598 *
599 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
600 * long *, arg4, size_t, arg4_len),
601 *
602 * * TP_FIELDS describes the event payload layout in the trace *
603 *
604 * TP_FIELDS(
605 * * Integer, printed in base 10 *
606 * ctf_integer(int, field_a, arg0)
607 *
608 * * Integer, printed with 0x base 16 *
609 * ctf_integer_hex(unsigned long, field_d, arg1)
610 *
611 * * Enumeration *
612 * ctf_enum(someproject_component, enum_name, int, field_e, arg0)
613 *
614 * * Array Sequence, printed as UTF8-encoded array of bytes *
615 * ctf_array_text(char, field_b, string, FIXED_LEN)
616 * ctf_sequence_text(char, field_c, string, size_t, strlen)
617 *
618 * * String, printed as UTF8-encoded string *
619 * ctf_string(field_e, string)
620 *
621 * * Array sequence of signed integer values *
622 * ctf_array(long, field_f, arg4, FIXED_LEN4)
623 * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
624 * )
625 * )
626 *
627 * More detailed explanation:
628 *
629 * The name of the tracepoint is expressed as a tuple with the provider
630 * and name arguments.
631 *
632 * The provider and name should be a proper C99 identifier.
633 * The "provider" and "name" MUST follow these rules to ensure no
634 * namespace clash occurs:
635 *
636 * For projects (applications and libraries) for which an entity
637 * specific to the project controls the source code and thus its
638 * tracepoints (typically with a scope larger than a single company):
639 *
640 * either:
641 * project_component, event
642 * or:
643 * project, event
644 *
645 * Where "project" is the name of the project,
646 * "component" is the name of the project component (which may
647 * include several levels of sub-components, e.g.
648 * ...component_subcomponent_...) where the tracepoint is located
649 * (optional),
650 * "event" is the name of the tracepoint event.
651 *
652 * For projects issued from a single company wishing to advertise that
653 * the company controls the source code and thus the tracepoints, the
654 * "com_" prefix should be used:
655 *
656 * either:
657 * com_company_project_component, event
658 * or:
659 * com_company_project, event
660 *
661 * Where "company" is the name of the company,
662 * "project" is the name of the project,
663 * "component" is the name of the project component (which may
664 * include several levels of sub-components, e.g.
665 * ...component_subcomponent_...) where the tracepoint is located
666 * (optional),
667 * "event" is the name of the tracepoint event.
668 *
669 * the provider:event identifier is limited to 127 characters.
670 */
671
672#define TRACEPOINT_EVENT(provider, name, args, fields) \
673 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
674 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
675
676#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
677
678#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
679 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
680 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
681
682#endif /* #ifndef TRACEPOINT_EVENT */
683
684#ifndef TRACEPOINT_LOGLEVEL
685
686/*
687 * Tracepoint Loglevels
688 *
689 * Typical use of these loglevels:
690 *
691 * The loglevels go from 0 to 14. Higher numbers imply the most
692 * verbosity (higher event throughput expected.
693 *
694 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
695 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
696 * debug information.
697 *
698 * TRACE_EMERG 0
699 * system is unusable
700 *
701 * TRACE_ALERT 1
702 * action must be taken immediately
703 *
704 * TRACE_CRIT 2
705 * critical conditions
706 *
707 * TRACE_ERR 3
708 * error conditions
709 *
710 * TRACE_WARNING 4
711 * warning conditions
712 *
713 * TRACE_NOTICE 5
714 * normal, but significant, condition
715 *
716 * TRACE_INFO 6
717 * informational message
718 *
719 * TRACE_DEBUG_SYSTEM 7
720 * debug information with system-level scope (set of programs)
721 *
722 * TRACE_DEBUG_PROGRAM 8
723 * debug information with program-level scope (set of processes)
724 *
725 * TRACE_DEBUG_PROCESS 9
726 * debug information with process-level scope (set of modules)
727 *
728 * TRACE_DEBUG_MODULE 10
729 * debug information with module (executable/library) scope (set of units)
730 *
731 * TRACE_DEBUG_UNIT 11
732 * debug information with compilation unit scope (set of functions)
733 *
734 * TRACE_DEBUG_FUNCTION 12
735 * debug information with function-level scope
736 *
737 * TRACE_DEBUG_LINE 13
738 * debug information with line-level scope (TRACEPOINT_EVENT default)
739 *
740 * TRACE_DEBUG 14
741 * debug-level message
742 *
743 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
744 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
745 * tracepoint name. The first field is the provider name, the second
746 * field is the name of the tracepoint, the third field is the loglevel
747 * name.
748 *
749 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
750 * < loglevel_name >)
751 *
752 * The TRACEPOINT_PROVIDER must be already declared before declaring a
753 * TRACEPOINT_LOGLEVEL.
754 */
755
756enum {
757 TRACE_EMERG = 0,
758 TRACE_ALERT = 1,
759 TRACE_CRIT = 2,
760 TRACE_ERR = 3,
761 TRACE_WARNING = 4,
762 TRACE_NOTICE = 5,
763 TRACE_INFO = 6,
764 TRACE_DEBUG_SYSTEM = 7,
765 TRACE_DEBUG_PROGRAM = 8,
766 TRACE_DEBUG_PROCESS = 9,
767 TRACE_DEBUG_MODULE = 10,
768 TRACE_DEBUG_UNIT = 11,
769 TRACE_DEBUG_FUNCTION = 12,
770 TRACE_DEBUG_LINE = 13,
771 TRACE_DEBUG = 14,
772};
773
774#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
775
776#endif /* #ifndef TRACEPOINT_LOGLEVEL */
777
778#ifndef TRACEPOINT_MODEL_EMF_URI
779
780#define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
781
782#endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */
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