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Fix: don't dereference NULL pointers
[lttng-ust.git] / include / lttng / tracepoint.h
CommitLineData
b728d87e
MD		 1#ifndef _LTTNG_TRACEPOINT_H
2#define _LTTNG_TRACEPOINT_H
3
4/*
e92f3e28 5 * Copyright 2011-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
b728d87e 6 *
e92f3e28
MD		 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:
b728d87e 13 *
e92f3e28
MD		 14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
d2428e87
MD		 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.
b728d87e
MD		 24 */
25
76aca78d
MD		 26#include <stdio.h>
27#include <stdlib.h>
8fce9e2b 28#include <lttng/tracepoint-types.h>
40b2b5a4 29#include <lttng/tracepoint-rcu.h>
b728d87e 30#include <urcu/compiler.h>
c082d14b 31#include <urcu/system.h>
deb6e540 32#include <dlfcn.h> /* for dlopen */
51920067 33#include <string.h> /* for memset */
b2f60c79 34#include <lttng/ust-config.h> /* for sdt */
a8909ba5 35#include <lttng/ust-compiler.h>
b2f60c79
MD		 36
37#ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
38#define SDT_USE_VARIADIC
39#include <sys/sdt.h>
40#else
41#define STAP_PROBEV(...)
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 { \
7cb85a18 56 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{ \
1a206094 167 struct lttng_ust_tracepoint_probe *__tp_probe; \
b728d87e 168 \
d3db6a40 169 if (caa_unlikely(!TP_RCU_LINK_TEST())) \
deb6e540 170 return; \
40b2b5a4 171 tp_rcu_read_lock_bp(); \
0f2f7e21 172 __tp_probe = tp_rcu_dereference_bp(__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: \
40b2b5a4 183 tp_rcu_read_unlock_bp(); \
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);
51920067
MD		 220#ifndef _LGPL_SOURCE
221 void (*rcu_read_lock_sym_bp)(void);
222 void (*rcu_read_unlock_sym_bp)(void);
223 void *(*rcu_dereference_sym_bp)(void *p);
224#endif
225};
226
1a206094 227extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen;
51920067 228
46c881a7
MD		 229#if defined(TRACEPOINT_DEFINE) || defined(TRACEPOINT_CREATE_PROBES)
230
231/*
232 * These weak symbols, the constructor, and destructor take care of
233 * registering only _one_ instance of the tracepoints per shared-ojbect
234 * (or for the whole main program).
235 */
236int __tracepoint_registered
237 __attribute__((weak, visibility("hidden")));
238int __tracepoint_ptrs_registered
239 __attribute__((weak, visibility("hidden")));
1a206094 240struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
46c881a7
MD		 241 __attribute__((weak, visibility("hidden")));
242
99234da6
MD		 243#ifndef _LGPL_SOURCE
244static inline void lttng_ust_notrace
245__tracepoint__init_urcu_sym(void);
246static inline void
247__tracepoint__init_urcu_sym(void)
248{
249 /*
250 * Symbols below are needed by tracepoint call sites and probe
251 * providers.
252 */
253 if (!tracepoint_dlopen.rcu_read_lock_sym_bp)
254 tracepoint_dlopen.rcu_read_lock_sym_bp =
255 URCU_FORCE_CAST(void (*)(void),
256 dlsym(tracepoint_dlopen.liblttngust_handle,
257 "tp_rcu_read_lock_bp"));
258 if (!tracepoint_dlopen.rcu_read_unlock_sym_bp)
259 tracepoint_dlopen.rcu_read_unlock_sym_bp =
260 URCU_FORCE_CAST(void (*)(void),
261 dlsym(tracepoint_dlopen.liblttngust_handle,
262 "tp_rcu_read_unlock_bp"));
263 if (!tracepoint_dlopen.rcu_dereference_sym_bp)
264 tracepoint_dlopen.rcu_dereference_sym_bp =
265 URCU_FORCE_CAST(void *(*)(void *p),
266 dlsym(tracepoint_dlopen.liblttngust_handle,
267 "tp_rcu_dereference_sym_bp"));
268}
269#else
270static inline void lttng_ust_notrace
271__tracepoint__init_urcu_sym(void);
272static inline void
273__tracepoint__init_urcu_sym(void)
274{
275}
276#endif
277
46c881a7
MD		 278static void lttng_ust_notrace __attribute__((constructor))
279__tracepoints__init(void);
280static void
281__tracepoints__init(void)
282{
283 if (__tracepoint_registered++)
284 return;
285
286 if (!tracepoint_dlopen.liblttngust_handle)
287 tracepoint_dlopen.liblttngust_handle =
288 dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
289 if (!tracepoint_dlopen.liblttngust_handle)
290 return;
99234da6 291 __tracepoint__init_urcu_sym();
46c881a7
MD		 292}
293
294static void lttng_ust_notrace __attribute__((destructor))
295__tracepoints__destroy(void);
296static void
297__tracepoints__destroy(void)
298{
299 int ret;
300
301 if (--__tracepoint_registered)
302 return;
303 if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_ptrs_registered) {
304 ret = dlclose(tracepoint_dlopen.liblttngust_handle);
76aca78d
MD		 305 if (ret) {
306 fprintf(stderr, "Error (%d) in dlclose\n", ret);
307 abort();
308 }
46c881a7
MD		 309 memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
310 }
311}
312
313#endif
314
deb6e540
MD		 315#ifdef TRACEPOINT_DEFINE
316
558b9d86
MD		 317/*
318 * These weak symbols, the constructor, and destructor take care of
319 * registering only _one_ instance of the tracepoints per shared-ojbect
320 * (or for the whole main program).
321 */
1a206094 322extern struct lttng_ust_tracepoint * const __start___tracepoints_ptrs[]
558b9d86 323 __attribute__((weak, visibility("hidden")));
1a206094 324extern struct lttng_ust_tracepoint * const __stop___tracepoints_ptrs[]
558b9d86
MD		 325 __attribute__((weak, visibility("hidden")));
326
628e1d81
MD		 327/*
328 * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
329 * unresolved symbol that requires the provider to be linked in. When
330 * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
331 * unresolved symbol that depends on having the provider linked in,
332 * otherwise the linker complains. This deals with use of static
333 * libraries, ensuring that the linker does not remove the provider
334 * object from the executable.
335 */
336#ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
b4f3bc52 337#define _TRACEPOINT_UNDEFINED_REF(provider) NULL
628e1d81 338#else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
b4f3bc52 339#define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
628e1d81
MD		 340#endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
341
b728d87e
MD		 342/*
343 * Note: to allow PIC code, we need to allow the linker to update the pointers
344 * in the __tracepoints_ptrs section.
345 * Therefore, this section is _not_ const (read-only).
346 */
b4f3bc52
MD		 347#define _TP_EXTRACT_STRING(...) #__VA_ARGS__
348
349#define _DEFINE_TRACEPOINT(_provider, _name, _args) \
350 extern int __tracepoint_provider_##_provider; \
351 static const char __tp_strtab_##_provider##___##_name[] \
b728d87e 352 __attribute__((section("__tracepoints_strings"))) = \
b4f3bc52 353 #_provider ":" #_name; \
1a206094 354 struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name \
b728d87e 355 __attribute__((section("__tracepoints"))) = \
b4f3bc52
MD		 356 { \
357 __tp_strtab_##_provider##___##_name, \
358 0, \
359 NULL, \
360 _TRACEPOINT_UNDEFINED_REF(_provider), \
361 _TP_EXTRACT_STRING(_args), \
10e594aa 362 { }, \
b4f3bc52 363 }; \
1a206094
SM		 364 static struct lttng_ust_tracepoint * \
365 __tracepoint_ptr_##_provider##___##_name \
b728d87e 366 __attribute__((used, section("__tracepoints_ptrs"))) = \
b4f3bc52 367 &__tracepoint_##_provider##___##_name;
b728d87e 368
a8909ba5 369static void lttng_ust_notrace __attribute__((constructor))
46c881a7 370__tracepoints__ptrs_init(void);
a8909ba5 371static void
46c881a7 372__tracepoints__ptrs_init(void)
b728d87e 373{
46c881a7 374 if (__tracepoint_ptrs_registered++)
b728d87e 375 return;
46c881a7
MD		 376 if (!tracepoint_dlopen.liblttngust_handle)
377 tracepoint_dlopen.liblttngust_handle =
378 dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
51920067 379 if (!tracepoint_dlopen.liblttngust_handle)
deb6e540 380 return;
99234da6 381 tracepoint_dlopen.tracepoint_register_lib =
1a206094 382 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int),
99234da6
MD		 383 dlsym(tracepoint_dlopen.liblttngust_handle,
384 "tracepoint_register_lib"));
385 tracepoint_dlopen.tracepoint_unregister_lib =
1a206094 386 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *),
99234da6
MD		 387 dlsym(tracepoint_dlopen.liblttngust_handle,
388 "tracepoint_unregister_lib"));
389 __tracepoint__init_urcu_sym();
390 if (tracepoint_dlopen.tracepoint_register_lib) {
391 tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs,
46c881a7
MD		 392 __stop___tracepoints_ptrs -
393 __start___tracepoints_ptrs);
99234da6 394 }
b728d87e
MD		 395}
396
a8909ba5 397static void lttng_ust_notrace __attribute__((destructor))
46c881a7 398__tracepoints__ptrs_destroy(void);
a8909ba5 399static void
46c881a7 400__tracepoints__ptrs_destroy(void)
b728d87e 401{
deb6e540 402 int ret;
51920067 403
46c881a7 404 if (--__tracepoint_ptrs_registered)
b728d87e 405 return;
46c881a7
MD		 406 if (tracepoint_dlopen.tracepoint_unregister_lib)
407 tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
408 if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_registered) {
51920067 409 ret = dlclose(tracepoint_dlopen.liblttngust_handle);
76aca78d
MD		 410 if (ret) {
411 fprintf(stderr, "Error (%d) in dlclose\n", ret);
412 abort();
413 }
51920067 414 memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
deb6e540 415 }
b728d87e
MD		 416}
417
46c881a7
MD		 418#else /* TRACEPOINT_DEFINE */
419
420#define _DEFINE_TRACEPOINT(_provider, _name, _args)
421
422#endif /* #else TRACEPOINT_DEFINE */
deb6e540 423
b728d87e
MD		 424#ifdef __cplusplus
425}
426#endif
427
428#endif /* _LTTNG_TRACEPOINT_H */
429
430/* The following declarations must be outside re-inclusion protection. */
431
432#ifndef TRACEPOINT_EVENT
433
434/*
435 * How to use the TRACEPOINT_EVENT macro:
436 *
437 * An example:
438 *
439 * TRACEPOINT_EVENT(someproject_component, event_name,
440 *
441 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
442 *
443 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
444 * long *, arg4, size_t, arg4_len),
445 *
446 * * TP_FIELDS describes the event payload layout in the trace *
447 *
448 * TP_FIELDS(
449 * * Integer, printed in base 10 *
450 * ctf_integer(int, field_a, arg0)
451 *
452 * * Integer, printed with 0x base 16 *
453 * ctf_integer_hex(unsigned long, field_d, arg1)
454 *
455 * * Array Sequence, printed as UTF8-encoded array of bytes *
456 * ctf_array_text(char, field_b, string, FIXED_LEN)
457 * ctf_sequence_text(char, field_c, string, size_t, strlen)
458 *
459 * * String, printed as UTF8-encoded string *
460 * ctf_string(field_e, string)
461 *
462 * * Array sequence of signed integer values *
463 * ctf_array(long, field_f, arg4, FIXED_LEN4)
464 * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
465 * )
466 * )
467 *
468 * More detailed explanation:
469 *
470 * The name of the tracepoint is expressed as a tuple with the provider
471 * and name arguments.
472 *
473 * The provider and name should be a proper C99 identifier.
474 * The "provider" and "name" MUST follow these rules to ensure no
475 * namespace clash occurs:
476 *
477 * For projects (applications and libraries) for which an entity
478 * specific to the project controls the source code and thus its
479 * tracepoints (typically with a scope larger than a single company):
480 *
481 * either:
482 * project_component, event
483 * or:
484 * project, event
485 *
486 * Where "project" is the name of the project,
487 * "component" is the name of the project component (which may
488 * include several levels of sub-components, e.g.
489 * ...component_subcomponent_...) where the tracepoint is located
490 * (optional),
491 * "event" is the name of the tracepoint event.
492 *
493 * For projects issued from a single company wishing to advertise that
494 * the company controls the source code and thus the tracepoints, the
495 * "com_" prefix should be used:
496 *
497 * either:
498 * com_company_project_component, event
499 * or:
500 * com_company_project, event
501 *
502 * Where "company" is the name of the company,
503 * "project" is the name of the project,
504 * "component" is the name of the project component (which may
505 * include several levels of sub-components, e.g.
506 * ...component_subcomponent_...) where the tracepoint is located
507 * (optional),
508 * "event" is the name of the tracepoint event.
509 *
510 * the provider:event identifier is limited to 127 characters.
511 */
512
b728d87e 513#define TRACEPOINT_EVENT(provider, name, args, fields) \
deb6e540 514 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
b4f3bc52 515 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
b728d87e
MD		 516
517#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
518
519#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
deb6e540 520 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
b4f3bc52 521 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
b728d87e
MD		 522
523#endif /* #ifndef TRACEPOINT_EVENT */
524
525#ifndef TRACEPOINT_LOGLEVEL
526
527/*
75c5ad79 528 * Tracepoint Loglevels
b728d87e
MD		 529 *
530 * Typical use of these loglevels:
531 *
d8de1354 532 * The loglevels go from 0 to 14. Higher numbers imply the most
75c5ad79
MD		 533 * verbosity (higher event throughput expected.
534 *
d8de1354
MD		 535 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
536 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
537 * debug information.
75c5ad79 538 *
d8de1354 539 * TRACE_EMERG 0
75c5ad79
MD		 540 * system is unusable
541 *
d8de1354 542 * TRACE_ALERT 1
75c5ad79
MD		 543 * action must be taken immediately
544 *
d8de1354 545 * TRACE_CRIT 2
75c5ad79
MD		 546 * critical conditions
547 *
d8de1354 548 * TRACE_ERR 3
75c5ad79
MD		 549 * error conditions
550 *
d8de1354 551 * TRACE_WARNING 4
75c5ad79
MD		 552 * warning conditions
553 *
d8de1354 554 * TRACE_NOTICE 5
75c5ad79
MD		 555 * normal, but significant, condition
556 *
d8de1354 557 * TRACE_INFO 6
75c5ad79
MD		 558 * informational message
559 *
d8de1354
MD		 560 * TRACE_DEBUG_SYSTEM 7
561 * debug information with system-level scope (set of programs)
75c5ad79 562 *
d8de1354
MD		 563 * TRACE_DEBUG_PROGRAM 8
564 * debug information with program-level scope (set of processes)
75c5ad79 565 *
d8de1354
MD		 566 * TRACE_DEBUG_PROCESS 9
567 * debug information with process-level scope (set of modules)
75c5ad79 568 *
d8de1354
MD		 569 * TRACE_DEBUG_MODULE 10
570 * debug information with module (executable/library) scope (set of units)
75c5ad79 571 *
d8de1354
MD		 572 * TRACE_DEBUG_UNIT 11
573 * debug information with compilation unit scope (set of functions)
75c5ad79 574 *
d8de1354
MD		 575 * TRACE_DEBUG_FUNCTION 12
576 * debug information with function-level scope
75c5ad79 577 *
d8de1354
MD		 578 * TRACE_DEBUG_LINE 13
579 * debug information with line-level scope (TRACEPOINT_EVENT default)
902e1379 580 *
d8de1354 581 * TRACE_DEBUG 14
1e3b0059 582 * debug-level message
75c5ad79
MD		 583 *
584 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
585 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
853cda88
MD		 586 * tracepoint name. The first field is the provider name, the second
587 * field is the name of the tracepoint, the third field is the loglevel
588 * name.
b728d87e
MD		 589 *
590 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
591 * < loglevel_name >)
592 *
75c5ad79
MD		 593 * The TRACEPOINT_PROVIDER must be already declared before declaring a
594 * TRACEPOINT_LOGLEVEL.
b728d87e
MD		 595 */
596
882a56d7 597enum {
d8de1354
MD		 598 TRACE_EMERG = 0,
599 TRACE_ALERT = 1,
600 TRACE_CRIT = 2,
601 TRACE_ERR = 3,
602 TRACE_WARNING = 4,
603 TRACE_NOTICE = 5,
604 TRACE_INFO = 6,
605 TRACE_DEBUG_SYSTEM = 7,
606 TRACE_DEBUG_PROGRAM = 8,
607 TRACE_DEBUG_PROCESS = 9,
608 TRACE_DEBUG_MODULE = 10,
609 TRACE_DEBUG_UNIT = 11,
610 TRACE_DEBUG_FUNCTION = 12,
611 TRACE_DEBUG_LINE = 13,
612 TRACE_DEBUG = 14,
882a56d7
MD		 613};
614
05ceaafd 615#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
b728d87e
MD		 616
617#endif /* #ifndef TRACEPOINT_LOGLEVEL */
6ddc916d
MD		 618
619#ifndef TRACEPOINT_MODEL_EMF_URI
620
621#define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
622
623#endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */
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