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[lttng-ust.git] / include / lttng / tracepoint.h
CommitLineData
b728d87e 1/*
c0c0989a 2 * SPDX-License-Identifier: MIT
b728d87e 3 *
c0c0989a 4 * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
b728d87e
MD		 5 */
6
c0c0989a
MJ		 7#ifndef _LTTNG_TRACEPOINT_H
8#define _LTTNG_TRACEPOINT_H
9
76aca78d
MD		 10#include <stdio.h>
11#include <stdlib.h>
8fce9e2b 12#include <lttng/tracepoint-types.h>
40b2b5a4 13#include <lttng/tracepoint-rcu.h>
b728d87e 14#include <urcu/compiler.h>
c082d14b 15#include <urcu/system.h>
deb6e540 16#include <dlfcn.h> /* for dlopen */
51920067 17#include <string.h> /* for memset */
b2f60c79 18#include <lttng/ust-config.h> /* for sdt */
a8909ba5 19#include <lttng/ust-compiler.h>
b2f60c79
MD		 20
21#ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
23b75ae5
MJ		 22/*
23 * Instead of using SDT_USE_VARIADIC from 'sys/sdt.h', use our own namespaced
24 * macros since the instrumented application might already have included
25 * 'sys/sdt.h' without variadic support.
26 */
b2f60c79 27#include <sys/sdt.h>
23b75ae5
MJ		 28
29#define _LTTNG_SDT_NARG(...) \
30 __LTTNG_SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0)
31
32#define __LTTNG_SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N
33
34#define _LTTNG_SDT_PROBE_N(provider, name, N, ...) \
35 _SDT_PROBE(provider, name, N, (__VA_ARGS__))
36
37#define LTTNG_STAP_PROBEV(provider, name, ...) \
38 _LTTNG_SDT_PROBE_N(provider, name, _LTTNG_SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__)
39
b2f60c79 40#else
afeea86f 41#define LTTNG_STAP_PROBEV(...)
b2f60c79 42#endif
b728d87e
MD		 43
44#ifdef __cplusplus
45extern "C" {
46#endif
47
8da6d0c8 48#define tracepoint_enabled(provider, name) \
c082d14b 49 caa_unlikely(CMM_LOAD_SHARED(__tracepoint_##provider##___##name.state))
8da6d0c8
DS		 50
51#define do_tracepoint(provider, name, ...) \
52 __tracepoint_cb_##provider##___##name(__VA_ARGS__)
53
23c8854a
MD		 54#define tracepoint(provider, name, ...) \
55 do { \
afeea86f 56 LTTNG_STAP_PROBEV(provider, name, ## __VA_ARGS__); \
8da6d0c8
DS		 57 if (tracepoint_enabled(provider, name)) \
58 do_tracepoint(provider, name, __VA_ARGS__); \
b728d87e
MD		 59 } while (0)
60
61#define TP_ARGS(...) __VA_ARGS__
62
63/*
64 * TP_ARGS takes tuples of type, argument separated by a comma.
65 * It can take up to 10 tuples (which means that less than 10 tuples is
66 * fine too).
67 * Each tuple is also separated by a comma.
68 */
df854e41
MD		 69#define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
70 _tokena##_tokenb
71#define _TP_COMBINE_TOKENS(_tokena, _tokenb) \
72 __TP_COMBINE_TOKENS(_tokena, _tokenb)
73#define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
74 _tokena##_tokenb##_tokenc
75#define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
76 __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
77#define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
78 _tokena##_tokenb##_tokenc##_tokend
79#define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
80 __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
b728d87e 81
4495dd39
MD		 82/*
83 * _TP_EXVAR* extract the var names.
84 * _TP_EXVAR1 and _TP_EXDATA_VAR1 are needed for -std=c99.
85 */
b728d87e 86#define _TP_EXVAR0()
4495dd39 87#define _TP_EXVAR1(a)
b728d87e
MD		 88#define _TP_EXVAR2(a,b) b
89#define _TP_EXVAR4(a,b,c,d) b,d
90#define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
91#define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
92#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
93#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
94#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
95#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
96#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
97#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
98
99#define _TP_EXDATA_VAR0() __tp_data
4495dd39 100#define _TP_EXDATA_VAR1(a) __tp_data
b728d87e
MD		 101#define _TP_EXDATA_VAR2(a,b) __tp_data,b
102#define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
103#define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
104#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
105#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
106#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
107#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
108#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
109#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
110#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
111
4495dd39
MD		 112/*
113 * _TP_EXPROTO* extract tuples of type, var.
114 * _TP_EXPROTO1 and _TP_EXDATA_PROTO1 are needed for -std=c99.
115 */
86637aa6 116#define _TP_EXPROTO0() void
4495dd39 117#define _TP_EXPROTO1(a) void
b728d87e
MD		 118#define _TP_EXPROTO2(a,b) a b
119#define _TP_EXPROTO4(a,b,c,d) a b,c d
120#define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
121#define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
122#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
123#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
124#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
125#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
126#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
127#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
128
129#define _TP_EXDATA_PROTO0() void *__tp_data
4495dd39 130#define _TP_EXDATA_PROTO1(a) void *__tp_data
b728d87e
MD		 131#define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
132#define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
133#define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
134#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
135#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
136#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
137#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
138#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
139#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
140#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
141
142/* Preprocessor trick to count arguments. Inspired from sdt.h. */
143#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)
144#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
23c8854a
MD		 145#define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
146#define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
147#define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
148#define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
b728d87e 149#define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
23c8854a 150#define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
b728d87e 151#define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
23c8854a 152#define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
b728d87e
MD		 153#define _TP_PARAMS(...) __VA_ARGS__
154
96f85541
MD		 155/*
156 * The tracepoint cb is marked always inline so we can distinguish
157 * between caller's ip addresses within the probe using the return
158 * address.
159 */
0f2f7e21 160#define _DECLARE_TRACEPOINT(_provider, _name, ...) \
1a206094 161extern struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name; \
17ca0600 162static inline __attribute__((always_inline, unused)) lttng_ust_notrace \
a8909ba5 163void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)); \
96f85541 164static \
a8909ba5 165void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
b728d87e 166{ \
10544ee8 167 struct lttng_ust_tracepoint_probe *__tp_probe; \
b728d87e 168 \
d3db6a40 169 if (caa_unlikely(!TP_RCU_LINK_TEST())) \
deb6e540 170 return; \
10544ee8
MD		 171 tp_rcu_read_lock(); \
172 __tp_probe = tp_rcu_dereference(__tracepoint_##_provider##___##_name.probes); \
23c8854a 173 if (caa_unlikely(!__tp_probe)) \
b728d87e
MD		 174 goto end; \
175 do { \
1a206094 176 void (*__tp_cb)(void) = __tp_probe->func; \
23c8854a 177 void *__tp_data = __tp_probe->data; \
b728d87e 178 \
23c8854a
MD		 179 URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
180 (_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
181 } while ((++__tp_probe)->func); \
b728d87e 182end: \
10544ee8 183 tp_rcu_read_unlock(); \
b728d87e 184} \
a8909ba5
PW		 185static inline lttng_ust_notrace \
186void __tracepoint_register_##_provider##___##_name(char *name, \
187 void (*func)(void), void *data); \
188static inline \
189void __tracepoint_register_##_provider##___##_name(char *name, \
190 void (*func)(void), void *data) \
b728d87e 191{ \
67e5f391
MD		 192 __tracepoint_probe_register(name, func, data, \
193 __tracepoint_##_provider##___##_name.signature); \
b728d87e 194} \
a8909ba5
PW		 195static inline lttng_ust_notrace \
196void __tracepoint_unregister_##_provider##___##_name(char *name, \
197 void (*func)(void), void *data); \
198static inline \
199void __tracepoint_unregister_##_provider##___##_name(char *name, \
200 void (*func)(void), void *data) \
b728d87e 201{ \
23c8854a 202 __tracepoint_probe_unregister(name, func, data); \
b728d87e
MD		 203}
204
fbdeb5ec
MD		 205extern int __tracepoint_probe_register(const char *name, void (*func)(void),
206 void *data, const char *signature);
207extern int __tracepoint_probe_unregister(const char *name, void (*func)(void),
208 void *data);
deb6e540 209
51920067
MD		 210/*
211 * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
212 * shared across objects in a module/main executable.
213 */
1a206094 214struct lttng_ust_tracepoint_dlopen {
51920067
MD		 215 void *liblttngust_handle;
216
1a206094 217 int (*tracepoint_register_lib)(struct lttng_ust_tracepoint * const *tracepoints_start,
51920067 218 int tracepoints_count);
1a206094 219 int (*tracepoint_unregister_lib)(struct lttng_ust_tracepoint * const *tracepoints_start);
10544ee8
MD		 220 void (*rcu_read_lock_sym)(void);
221 void (*rcu_read_unlock_sym)(void);
222 void *(*rcu_dereference_sym)(void *p);
51920067
MD		 223};
224
1a206094 225extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen;
f4624de2 226extern struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr;
51920067 227
46c881a7
MD		 228/*
229 * These weak symbols, the constructor, and destructor take care of
230 * registering only _one_ instance of the tracepoints per shared-ojbect
231 * (or for the whole main program).
232 */
233int __tracepoint_registered
234 __attribute__((weak, visibility("hidden")));
235int __tracepoint_ptrs_registered
236 __attribute__((weak, visibility("hidden")));
1a206094 237struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
46c881a7 238 __attribute__((weak, visibility("hidden")));
9443a022
MD		 239/*
240 * Deal with gcc O1 optimisation issues with weak hidden symbols. gcc
241 * 4.8 and prior does not have the same behavior for symbol scoping on
242 * 32-bit powerpc depending on the object size: symbols for objects of 8
243 * bytes or less have the same address throughout a module, whereas they
244 * have different addresses between compile units for objects larger
245 * than 8 bytes. Add this pointer indirection to ensure that the symbol
246 * scoping match that of the other weak hidden symbols found in this
247 * header.
248 */
249struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr
250 __attribute__((weak, visibility("hidden")));
46c881a7 251
0fd0de10
FD		 252/*
253 * Tracepoint dynamic linkage handling (callbacks). Hidden visibility: shared
254 * across objects in a module/main executable. The callbacks are used to
255 * control and check if the destructors should be executed.
256 */
257struct lttng_ust_tracepoint_destructors_syms {
0fd0de10
FD		 258 void (*tracepoint_disable_destructors)(void);
259 int (*tracepoint_get_destructors_state)(void);
260};
261
262extern struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms;
263extern struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr;
264
265struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms
266 __attribute__((weak, visibility("hidden")));
267struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr
268 __attribute__((weak, visibility("hidden")));
269
270static inline void tracepoint_disable_destructors(void)
271{
272 if (!tracepoint_dlopen_ptr)
273 tracepoint_dlopen_ptr = &tracepoint_dlopen;
274 if (!tracepoint_destructors_syms_ptr)
275 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
276 if (tracepoint_dlopen_ptr->liblttngust_handle
277 && tracepoint_destructors_syms_ptr->tracepoint_disable_destructors)
278 tracepoint_destructors_syms_ptr->tracepoint_disable_destructors();
0fd0de10
FD		 279}
280
99234da6
MD		 281#ifndef _LGPL_SOURCE
282static inline void lttng_ust_notrace
283__tracepoint__init_urcu_sym(void);
284static inline void
285__tracepoint__init_urcu_sym(void)
286{
9443a022
MD		 287 if (!tracepoint_dlopen_ptr)
288 tracepoint_dlopen_ptr = &tracepoint_dlopen;
99234da6
MD		 289 /*
290 * Symbols below are needed by tracepoint call sites and probe
291 * providers.
292 */
10544ee8
MD		 293 if (!tracepoint_dlopen_ptr->rcu_read_lock_sym)
294 tracepoint_dlopen_ptr->rcu_read_lock_sym =
99234da6 295 URCU_FORCE_CAST(void (*)(void),
9443a022 296 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
10544ee8
MD		 297 "tp_rcu_read_lock"));
298 if (!tracepoint_dlopen_ptr->rcu_read_unlock_sym)
299 tracepoint_dlopen_ptr->rcu_read_unlock_sym =
99234da6 300 URCU_FORCE_CAST(void (*)(void),
9443a022 301 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
10544ee8
MD		 302 "tp_rcu_read_unlock"));
303 if (!tracepoint_dlopen_ptr->rcu_dereference_sym)
304 tracepoint_dlopen_ptr->rcu_dereference_sym =
99234da6 305 URCU_FORCE_CAST(void *(*)(void *p),
9443a022 306 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
10544ee8 307 "tp_rcu_dereference_sym"));
99234da6
MD		 308}
309#else
310static inline void lttng_ust_notrace
311__tracepoint__init_urcu_sym(void);
312static inline void
313__tracepoint__init_urcu_sym(void)
314{
315}
316#endif
317
46c881a7
MD		 318static void lttng_ust_notrace __attribute__((constructor))
319__tracepoints__init(void);
320static void
321__tracepoints__init(void)
322{
8f0d1c78
MD		 323 if (__tracepoint_registered++) {
324 if (!tracepoint_dlopen_ptr->liblttngust_handle)
325 return;
326 __tracepoint__init_urcu_sym();
46c881a7 327 return;
8f0d1c78 328 }
46c881a7 329
9443a022
MD		 330 if (!tracepoint_dlopen_ptr)
331 tracepoint_dlopen_ptr = &tracepoint_dlopen;
332 if (!tracepoint_dlopen_ptr->liblttngust_handle)
333 tracepoint_dlopen_ptr->liblttngust_handle =
05e8ff1f 334 dlopen("liblttng-ust-tracepoint.so.1", RTLD_NOW | RTLD_GLOBAL);
9443a022 335 if (!tracepoint_dlopen_ptr->liblttngust_handle)
46c881a7 336 return;
99234da6 337 __tracepoint__init_urcu_sym();
46c881a7
MD		 338}
339
340static void lttng_ust_notrace __attribute__((destructor))
341__tracepoints__destroy(void);
342static void
343__tracepoints__destroy(void)
344{
345 int ret;
346
347 if (--__tracepoint_registered)
348 return;
9443a022
MD		 349 if (!tracepoint_dlopen_ptr)
350 tracepoint_dlopen_ptr = &tracepoint_dlopen;
0fd0de10
FD		 351 if (!tracepoint_destructors_syms_ptr)
352 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
353 if (!tracepoint_dlopen_ptr->liblttngust_handle)
354 return;
355 if (__tracepoint_ptrs_registered)
356 return;
357 /*
358 * Lookup if destructors must be executed using the new method.
359 */
360 if (tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
361 && !tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()) {
362 /*
363 * The tracepoint_get_destructors_state symbol was found with
364 * dlsym but its returned value is 0 meaning that destructors
365 * must not be executed.
366 */
367 return;
368 }
0fd0de10
FD		 369 ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
370 if (ret) {
371 fprintf(stderr, "Error (%d) in dlclose\n", ret);
372 abort();
373 }
374 memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
46c881a7
MD		 375}
376
deb6e540
MD		 377#ifdef TRACEPOINT_DEFINE
378
558b9d86
MD		 379/*
380 * These weak symbols, the constructor, and destructor take care of
381 * registering only _one_ instance of the tracepoints per shared-ojbect
382 * (or for the whole main program).
383 */
1a206094 384extern struct lttng_ust_tracepoint * const __start___tracepoints_ptrs[]
558b9d86 385 __attribute__((weak, visibility("hidden")));
1a206094 386extern struct lttng_ust_tracepoint * const __stop___tracepoints_ptrs[]
558b9d86
MD		 387 __attribute__((weak, visibility("hidden")));
388
628e1d81
MD		 389/*
390 * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
391 * unresolved symbol that requires the provider to be linked in. When
392 * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
393 * unresolved symbol that depends on having the provider linked in,
394 * otherwise the linker complains. This deals with use of static
395 * libraries, ensuring that the linker does not remove the provider
396 * object from the executable.
397 */
398#ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
b4f3bc52 399#define _TRACEPOINT_UNDEFINED_REF(provider) NULL
628e1d81 400#else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
b4f3bc52 401#define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
628e1d81
MD		 402#endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
403
b728d87e
MD		 404/*
405 * Note: to allow PIC code, we need to allow the linker to update the pointers
406 * in the __tracepoints_ptrs section.
407 * Therefore, this section is _not_ const (read-only).
408 */
b4f3bc52
MD		 409#define _TP_EXTRACT_STRING(...) #__VA_ARGS__
410
411#define _DEFINE_TRACEPOINT(_provider, _name, _args) \
412 extern int __tracepoint_provider_##_provider; \
413 static const char __tp_strtab_##_provider##___##_name[] \
b728d87e 414 __attribute__((section("__tracepoints_strings"))) = \
b4f3bc52 415 #_provider ":" #_name; \
1a206094 416 struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name \
b728d87e 417 __attribute__((section("__tracepoints"))) = \
b4f3bc52
MD		 418 { \
419 __tp_strtab_##_provider##___##_name, \
420 0, \
421 NULL, \
422 _TRACEPOINT_UNDEFINED_REF(_provider), \
423 _TP_EXTRACT_STRING(_args), \
10e594aa 424 { }, \
b4f3bc52 425 }; \
1a206094
SM		 426 static struct lttng_ust_tracepoint * \
427 __tracepoint_ptr_##_provider##___##_name \
4f74bc5e
MD		 428 __attribute__((section("__tracepoints_ptrs"), used)) \
429 __lttng_ust_variable_attribute_no_sanitize_address = \
b4f3bc52 430 &__tracepoint_##_provider##___##_name;
b728d87e 431
a8909ba5 432static void lttng_ust_notrace __attribute__((constructor))
46c881a7 433__tracepoints__ptrs_init(void);
a8909ba5 434static void
46c881a7 435__tracepoints__ptrs_init(void)
b728d87e 436{
46c881a7 437 if (__tracepoint_ptrs_registered++)
b728d87e 438 return;
9443a022
MD		 439 if (!tracepoint_dlopen_ptr)
440 tracepoint_dlopen_ptr = &tracepoint_dlopen;
441 if (!tracepoint_dlopen_ptr->liblttngust_handle)
442 tracepoint_dlopen_ptr->liblttngust_handle =
05e8ff1f 443 dlopen("liblttng-ust-tracepoint.so.1", RTLD_NOW | RTLD_GLOBAL);
9443a022 444 if (!tracepoint_dlopen_ptr->liblttngust_handle)
deb6e540 445 return;
0fd0de10
FD		 446 if (!tracepoint_destructors_syms_ptr)
447 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
9443a022 448 tracepoint_dlopen_ptr->tracepoint_register_lib =
1a206094 449 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int),
9443a022 450 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
ae14f822 451 "tracepoint_register_lib"));
9443a022 452 tracepoint_dlopen_ptr->tracepoint_unregister_lib =
1a206094 453 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *),
9443a022 454 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
ae14f822 455 "tracepoint_unregister_lib"));
0fd0de10
FD		 456 tracepoint_destructors_syms_ptr->tracepoint_disable_destructors =
457 URCU_FORCE_CAST(void (*)(void),
458 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
459 "tp_disable_destructors"));
460 tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state =
461 URCU_FORCE_CAST(int (*)(void),
462 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
463 "tp_get_destructors_state"));
99234da6 464 __tracepoint__init_urcu_sym();
9443a022
MD		 465 if (tracepoint_dlopen_ptr->tracepoint_register_lib) {
466 tracepoint_dlopen_ptr->tracepoint_register_lib(__start___tracepoints_ptrs,
46c881a7
MD		 467 __stop___tracepoints_ptrs -
468 __start___tracepoints_ptrs);
99234da6 469 }
b728d87e
MD		 470}
471
a8909ba5 472static void lttng_ust_notrace __attribute__((destructor))
46c881a7 473__tracepoints__ptrs_destroy(void);
a8909ba5 474static void
46c881a7 475__tracepoints__ptrs_destroy(void)
b728d87e 476{
deb6e540 477 int ret;
51920067 478
46c881a7 479 if (--__tracepoint_ptrs_registered)
b728d87e 480 return;
9443a022
MD		 481 if (!tracepoint_dlopen_ptr)
482 tracepoint_dlopen_ptr = &tracepoint_dlopen;
0fd0de10
FD		 483 if (!tracepoint_destructors_syms_ptr)
484 tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
9443a022
MD		 485 if (tracepoint_dlopen_ptr->tracepoint_unregister_lib)
486 tracepoint_dlopen_ptr->tracepoint_unregister_lib(__start___tracepoints_ptrs);
0fd0de10
FD		 487 if (tracepoint_dlopen_ptr->liblttngust_handle
488 && tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
489 && tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()
664ccf24 490 && !__tracepoint_ptrs_registered) {
9443a022 491 ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
76aca78d
MD		 492 if (ret) {
493 fprintf(stderr, "Error (%d) in dlclose\n", ret);
494 abort();
495 }
9443a022 496 memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
deb6e540 497 }
b728d87e
MD		 498}
499
46c881a7
MD		 500#else /* TRACEPOINT_DEFINE */
501
502#define _DEFINE_TRACEPOINT(_provider, _name, _args)
503
504#endif /* #else TRACEPOINT_DEFINE */
deb6e540 505
b728d87e
MD		 506#ifdef __cplusplus
507}
508#endif
509
510#endif /* _LTTNG_TRACEPOINT_H */
511
512/* The following declarations must be outside re-inclusion protection. */
513
c785c634
MD		 514#ifndef TRACEPOINT_ENUM
515
516/*
517 * Tracepoint Enumerations
518 *
519 * The enumeration is a mapping between an integer, or range of integers, and
520 * a string. It can be used to have a more compact trace in cases where the
521 * possible values for a field are limited:
522 *
523 * An example:
524 *
525 * TRACEPOINT_ENUM(someproject_component, enumname,
526 * TP_ENUM_VALUES(
527 * ctf_enum_value("even", 0)
528 * ctf_enum_value("uneven", 1)
529 * ctf_enum_range("twoto4", 2, 4)
530 * ctf_enum_value("five", 5)
531 * )
532 * )
533 *
534 * Where "someproject_component" is the name of the component this enumeration
535 * belongs to and "enumname" identifies this enumeration. Inside the
536 * TP_ENUM_VALUES macro is the actual mapping. Each string value can map
537 * to either a single value with ctf_enum_value or a range of values
538 * with ctf_enum_range.
539 *
540 * Enumeration ranges may overlap, but the behavior is implementation-defined,
541 * each trace reader will handle overlapping as it wishes.
542 *
543 * That enumeration can then be used in a field inside the TP_FIELD macro using
544 * the following line:
545 *
546 * ctf_enum(someproject_component, enumname, enumtype, enumfield, enumval)
547 *
548 * Where "someproject_component" and "enumname" match those in the
549 * TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
550 * backing the enumeration, "enumfield" is the name of the field and
551 * "enumval" is the value.
552 */
553
554#define TRACEPOINT_ENUM(provider, name, values)
555
556#endif /* #ifndef TRACEPOINT_ENUM */
557
b728d87e
MD		 558#ifndef TRACEPOINT_EVENT
559
560/*
561 * How to use the TRACEPOINT_EVENT macro:
562 *
563 * An example:
a60af3a5 564 *
b728d87e
MD		 565 * TRACEPOINT_EVENT(someproject_component, event_name,
566 *
567 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
568 *
569 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
570 * long *, arg4, size_t, arg4_len),
571 *
572 * * TP_FIELDS describes the event payload layout in the trace *
573 *
574 * TP_FIELDS(
a60af3a5 575 * * Integer, printed in base 10 *
b728d87e
MD		 576 * ctf_integer(int, field_a, arg0)
577 *
a60af3a5 578 * * Integer, printed with 0x base 16 *
b728d87e
MD		 579 * ctf_integer_hex(unsigned long, field_d, arg1)
580 *
c785c634
MD		 581 * * Enumeration *
582 * ctf_enum(someproject_component, enum_name, int, field_e, arg0)
583 *
a60af3a5 584 * * Array Sequence, printed as UTF8-encoded array of bytes *
b728d87e
MD		 585 * ctf_array_text(char, field_b, string, FIXED_LEN)
586 * ctf_sequence_text(char, field_c, string, size_t, strlen)
587 *
a60af3a5 588 * * String, printed as UTF8-encoded string *
b728d87e
MD		 589 * ctf_string(field_e, string)
590 *
a60af3a5 591 * * Array sequence of signed integer values *
b728d87e
MD		 592 * ctf_array(long, field_f, arg4, FIXED_LEN4)
593 * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
594 * )
595 * )
596 *
597 * More detailed explanation:
598 *
599 * The name of the tracepoint is expressed as a tuple with the provider
600 * and name arguments.
601 *
602 * The provider and name should be a proper C99 identifier.
603 * The "provider" and "name" MUST follow these rules to ensure no
604 * namespace clash occurs:
605 *
606 * For projects (applications and libraries) for which an entity
607 * specific to the project controls the source code and thus its
608 * tracepoints (typically with a scope larger than a single company):
609 *
610 * either:
611 * project_component, event
612 * or:
613 * project, event
614 *
615 * Where "project" is the name of the project,
616 * "component" is the name of the project component (which may
617 * include several levels of sub-components, e.g.
618 * ...component_subcomponent_...) where the tracepoint is located
619 * (optional),
620 * "event" is the name of the tracepoint event.
621 *
622 * For projects issued from a single company wishing to advertise that
623 * the company controls the source code and thus the tracepoints, the
624 * "com_" prefix should be used:
625 *
626 * either:
627 * com_company_project_component, event
628 * or:
629 * com_company_project, event
630 *
631 * Where "company" is the name of the company,
632 * "project" is the name of the project,
633 * "component" is the name of the project component (which may
634 * include several levels of sub-components, e.g.
635 * ...component_subcomponent_...) where the tracepoint is located
636 * (optional),
637 * "event" is the name of the tracepoint event.
638 *
639 * the provider:event identifier is limited to 127 characters.
640 */
641
b728d87e 642#define TRACEPOINT_EVENT(provider, name, args, fields) \
deb6e540 643 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
b4f3bc52 644 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
b728d87e
MD		 645
646#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
647
648#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
deb6e540 649 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
b4f3bc52 650 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
b728d87e
MD		 651
652#endif /* #ifndef TRACEPOINT_EVENT */
653
654#ifndef TRACEPOINT_LOGLEVEL
655
656/*
75c5ad79 657 * Tracepoint Loglevels
b728d87e
MD		 658 *
659 * Typical use of these loglevels:
660 *
d8de1354 661 * The loglevels go from 0 to 14. Higher numbers imply the most
75c5ad79
MD		 662 * verbosity (higher event throughput expected.
663 *
d8de1354
MD		 664 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
665 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
666 * debug information.
75c5ad79 667 *
d8de1354 668 * TRACE_EMERG 0
75c5ad79
MD		 669 * system is unusable
670 *
d8de1354 671 * TRACE_ALERT 1
75c5ad79
MD		 672 * action must be taken immediately
673 *
d8de1354 674 * TRACE_CRIT 2
75c5ad79
MD		 675 * critical conditions
676 *
d8de1354 677 * TRACE_ERR 3
75c5ad79
MD		 678 * error conditions
679 *
d8de1354 680 * TRACE_WARNING 4
75c5ad79
MD		 681 * warning conditions
682 *
d8de1354 683 * TRACE_NOTICE 5
75c5ad79
MD		 684 * normal, but significant, condition
685 *
d8de1354 686 * TRACE_INFO 6
75c5ad79
MD		 687 * informational message
688 *
d8de1354
MD		 689 * TRACE_DEBUG_SYSTEM 7
690 * debug information with system-level scope (set of programs)
75c5ad79 691 *
d8de1354
MD		 692 * TRACE_DEBUG_PROGRAM 8
693 * debug information with program-level scope (set of processes)
75c5ad79 694 *
d8de1354
MD		 695 * TRACE_DEBUG_PROCESS 9
696 * debug information with process-level scope (set of modules)
75c5ad79 697 *
d8de1354
MD		 698 * TRACE_DEBUG_MODULE 10
699 * debug information with module (executable/library) scope (set of units)
75c5ad79 700 *
d8de1354
MD		 701 * TRACE_DEBUG_UNIT 11
702 * debug information with compilation unit scope (set of functions)
75c5ad79 703 *
d8de1354
MD		 704 * TRACE_DEBUG_FUNCTION 12
705 * debug information with function-level scope
75c5ad79 706 *
d8de1354
MD		 707 * TRACE_DEBUG_LINE 13
708 * debug information with line-level scope (TRACEPOINT_EVENT default)
902e1379 709 *
d8de1354 710 * TRACE_DEBUG 14
1e3b0059 711 * debug-level message
75c5ad79
MD		 712 *
713 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
714 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
853cda88
MD		 715 * tracepoint name. The first field is the provider name, the second
716 * field is the name of the tracepoint, the third field is the loglevel
717 * name.
b728d87e
MD		 718 *
719 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
720 * < loglevel_name >)
721 *
75c5ad79
MD		 722 * The TRACEPOINT_PROVIDER must be already declared before declaring a
723 * TRACEPOINT_LOGLEVEL.
b728d87e
MD		 724 */
725
882a56d7 726enum {
d8de1354
MD		 727 TRACE_EMERG = 0,
728 TRACE_ALERT = 1,
729 TRACE_CRIT = 2,
730 TRACE_ERR = 3,
731 TRACE_WARNING = 4,
732 TRACE_NOTICE = 5,
733 TRACE_INFO = 6,
734 TRACE_DEBUG_SYSTEM = 7,
735 TRACE_DEBUG_PROGRAM = 8,
736 TRACE_DEBUG_PROCESS = 9,
737 TRACE_DEBUG_MODULE = 10,
738 TRACE_DEBUG_UNIT = 11,
739 TRACE_DEBUG_FUNCTION = 12,
740 TRACE_DEBUG_LINE = 13,
741 TRACE_DEBUG = 14,
882a56d7
MD		 742};
743
05ceaafd 744#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
b728d87e
MD		 745
746#endif /* #ifndef TRACEPOINT_LOGLEVEL */
6ddc916d
MD		 747
748#ifndef TRACEPOINT_MODEL_EMF_URI
749
750#define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
751
752#endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */
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