include/lttng/tracepoint.h

   1 #ifndef _LTTNG_TRACEPOINT_H
   2 #define _LTTNG_TRACEPOINT_H
   3
   4 /*
   5  * Copyright 2011-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  */
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <lttng/tracepoint-types.h>
  29 #include <lttng/tracepoint-rcu.h>
  30 #include <urcu/compiler.h>
  31 #include <dlfcn.h>      /* for dlopen */
  32 #include <string.h>     /* for memset */
  33 #include <lttng/ust-config.h>   /* for sdt */
  34 #include <lttng/ust-compiler.h>
  35
  36 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
  37 #define SDT_USE_VARIADIC
  38 #include <sys/sdt.h>
  39 #else
  40 #define STAP_PROBEV(...)
  41 #endif
  42
  43 #ifdef __cplusplus
  44 extern "C" {
  45 #endif
  46
  47 #define tracepoint_enabled(provider, name) \
  48         caa_unlikely(__tracepoint_##provider##___##name.state)
  49
  50 #define do_tracepoint(provider, name, ...) \
  51         __tracepoint_cb_##provider##___##name(__VA_ARGS__)
  52
  53 #define tracepoint(provider, name, ...)                                     \
  54         do {                                                                \
  55                 STAP_PROBEV(provider, name, ## __VA_ARGS__);                \
  56                 if (tracepoint_enabled(provider, name))                     \
  57                         do_tracepoint(provider, name, __VA_ARGS__);         \
  58         } while (0)
  59
  60 #define TP_ARGS(...)       __VA_ARGS__
  61
  62 /*
  63  * TP_ARGS takes tuples of type, argument separated by a comma.
  64  * It can take up to 10 tuples (which means that less than 10 tuples is
  65  * fine too).
  66  * Each tuple is also separated by a comma.
  67  */
  68 #define __TP_COMBINE_TOKENS(_tokena, _tokenb)                           \
  69                 _tokena##_tokenb
  70 #define _TP_COMBINE_TOKENS(_tokena, _tokenb)                            \
  71                 __TP_COMBINE_TOKENS(_tokena, _tokenb)
  72 #define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)                 \
  73                 _tokena##_tokenb##_tokenc
  74 #define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)                  \
  75                 __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
  76 #define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)        \
  77                 _tokena##_tokenb##_tokenc##_tokend
  78 #define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)         \
  79                 __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
  80
  81 /*
  82  * _TP_EXVAR* extract the var names.
  83  * _TP_EXVAR1 and _TP_EXDATA_VAR1 are needed for -std=c99.
  84  */
  85 #define _TP_EXVAR0()
  86 #define _TP_EXVAR1(a)
  87 #define _TP_EXVAR2(a,b)                                         b
  88 #define _TP_EXVAR4(a,b,c,d)                                     b,d
  89 #define _TP_EXVAR6(a,b,c,d,e,f)                                 b,d,f
  90 #define _TP_EXVAR8(a,b,c,d,e,f,g,h)                             b,d,f,h
  91 #define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j)                        b,d,f,h,j
  92 #define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l)                    b,d,f,h,j,l
  93 #define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n)                b,d,f,h,j,l,n
  94 #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
  95 #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
  96 #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
  97
  98 #define _TP_EXDATA_VAR0()                                               __tp_data
  99 #define _TP_EXDATA_VAR1(a)                                              __tp_data
 100 #define _TP_EXDATA_VAR2(a,b)                                            __tp_data,b
 101 #define _TP_EXDATA_VAR4(a,b,c,d)                                        __tp_data,b,d
 102 #define _TP_EXDATA_VAR6(a,b,c,d,e,f)                                    __tp_data,b,d,f
 103 #define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h)                                __tp_data,b,d,f,h
 104 #define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j)                           __tp_data,b,d,f,h,j
 105 #define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l)                       __tp_data,b,d,f,h,j,l
 106 #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
 107 #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
 108 #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
 109 #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
 110
 111 /*
 112  * _TP_EXPROTO* extract tuples of type, var.
 113  * _TP_EXPROTO1 and _TP_EXDATA_PROTO1 are needed for -std=c99.
 114  */
 115 #define _TP_EXPROTO0()                                          void
 116 #define _TP_EXPROTO1(a)                                         void
 117 #define _TP_EXPROTO2(a,b)                                       a b
 118 #define _TP_EXPROTO4(a,b,c,d)                                   a b,c d
 119 #define _TP_EXPROTO6(a,b,c,d,e,f)                               a b,c d,e f
 120 #define _TP_EXPROTO8(a,b,c,d,e,f,g,h)                           a b,c d,e f,g h
 121 #define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j)                      a b,c d,e f,g h,i j
 122 #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
 123 #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
 124 #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
 125 #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
 126 #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
 127
 128 #define _TP_EXDATA_PROTO0()                                             void *__tp_data
 129 #define _TP_EXDATA_PROTO1(a)                                            void *__tp_data
 130 #define _TP_EXDATA_PROTO2(a,b)                                          void *__tp_data,a b
 131 #define _TP_EXDATA_PROTO4(a,b,c,d)                                      void *__tp_data,a b,c d
 132 #define _TP_EXDATA_PROTO6(a,b,c,d,e,f)                                  void *__tp_data,a b,c d,e f
 133 #define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h)                              void *__tp_data,a b,c d,e f,g h
 134 #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
 135 #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
 136 #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
 137 #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
 138 #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
 139 #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
 140
 141 /* Preprocessor trick to count arguments. Inspired from sdt.h. */
 142 #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)
 143 #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
 144 #define _TP_PROTO_N(N, ...)             _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
 145 #define _TP_VAR_N(N, ...)               _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
 146 #define _TP_DATA_PROTO_N(N, ...)        _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
 147 #define _TP_DATA_VAR_N(N, ...)          _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
 148 #define _TP_ARGS_PROTO(...)             _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 149 #define _TP_ARGS_VAR(...)               _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 150 #define _TP_ARGS_DATA_PROTO(...)        _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 151 #define _TP_ARGS_DATA_VAR(...)          _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 152 #define _TP_PARAMS(...)                 __VA_ARGS__
 153
 154 /*
 155  * The tracepoint cb is marked always inline so we can distinguish
 156  * between caller's ip addresses within the probe using the return
 157  * address.
 158  */
 159 #define _DECLARE_TRACEPOINT(_provider, _name, ...)                                      \
 160 extern struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name;                \
 161 static inline __attribute__((always_inline, unused)) lttng_ust_notrace                  \
 162 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__));              \
 163 static                                                                                  \
 164 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__))               \
 165 {                                                                                       \
 166         struct lttng_ust_tracepoint_probe *__tp_probe;                                          \
 167                                                                                         \
 168         if (caa_unlikely(!TP_RCU_LINK_TEST()))                                          \
 169                 return;                                                                 \
 170         tp_rcu_read_lock_bp();                                                          \
 171         __tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
 172         if (caa_unlikely(!__tp_probe))                                                  \
 173                 goto end;                                                               \
 174         do {                                                                            \
 175                 void (*__tp_cb)(void) = __tp_probe->func;                               \
 176                 void *__tp_data = __tp_probe->data;                                     \
 177                                                                                         \
 178                 URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb)    \
 179                                 (_TP_ARGS_DATA_VAR(__VA_ARGS__));                       \
 180         } while ((++__tp_probe)->func);                                                 \
 181 end:                                                                                    \
 182         tp_rcu_read_unlock_bp();                                                        \
 183 }                                                                                       \
 184 static inline lttng_ust_notrace                                                         \
 185 void __tracepoint_register_##_provider##___##_name(char *name,                          \
 186                 void (*func)(void), void *data);                                        \
 187 static inline                                                                           \
 188 void __tracepoint_register_##_provider##___##_name(char *name,                          \
 189                 void (*func)(void), void *data)                                         \
 190 {                                                                                       \
 191         __tracepoint_probe_register(name, func, data,                                   \
 192                 __tracepoint_##_provider##___##_name.signature);                        \
 193 }                                                                                       \
 194 static inline lttng_ust_notrace                                                         \
 195 void __tracepoint_unregister_##_provider##___##_name(char *name,                        \
 196                 void (*func)(void), void *data);                                        \
 197 static inline                                                                           \
 198 void __tracepoint_unregister_##_provider##___##_name(char *name,                        \
 199                 void (*func)(void), void *data)                                         \
 200 {                                                                                       \
 201         __tracepoint_probe_unregister(name, func, data);                                \
 202 }
 203
 204 extern int __tracepoint_probe_register(const char *name, void (*func)(void),
 205                 void *data, const char *signature);
 206 extern int __tracepoint_probe_unregister(const char *name, void (*func)(void),
 207                 void *data);
 208
 209 /*
 210  * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
 211  * shared across objects in a module/main executable.
 212  */
 213 struct lttng_ust_tracepoint_dlopen {
 214         void *liblttngust_handle;
 215
 216         int (*tracepoint_register_lib)(struct lttng_ust_tracepoint * const *tracepoints_start,
 217                 int tracepoints_count);
 218         int (*tracepoint_unregister_lib)(struct lttng_ust_tracepoint * const *tracepoints_start);
 219 #ifndef _LGPL_SOURCE
 220         void (*rcu_read_lock_sym_bp)(void);
 221         void (*rcu_read_unlock_sym_bp)(void);
 222         void *(*rcu_dereference_sym_bp)(void *p);
 223 #endif
 224 };
 225
 226 extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen;
 227
 228 #if defined(TRACEPOINT_DEFINE) || defined(TRACEPOINT_CREATE_PROBES)
 229
 230 /*
 231  * These weak symbols, the constructor, and destructor take care of
 232  * registering only _one_ instance of the tracepoints per shared-ojbect
 233  * (or for the whole main program).
 234  */
 235 int __tracepoint_registered
 236         __attribute__((weak, visibility("hidden")));
 237 int __tracepoint_ptrs_registered
 238         __attribute__((weak, visibility("hidden")));
 239 struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
 240         __attribute__((weak, visibility("hidden")));
 241
 242 #ifndef _LGPL_SOURCE
 243 static inline void lttng_ust_notrace
 244 __tracepoint__init_urcu_sym(void);
 245 static inline void
 246 __tracepoint__init_urcu_sym(void)
 247 {
 248         /*
 249          * Symbols below are needed by tracepoint call sites and probe
 250          * providers.
 251          */
 252         if (!tracepoint_dlopen.rcu_read_lock_sym_bp)
 253                 tracepoint_dlopen.rcu_read_lock_sym_bp =
 254                         URCU_FORCE_CAST(void (*)(void),
 255                                 dlsym(tracepoint_dlopen.liblttngust_handle,
 256                                         "tp_rcu_read_lock_bp"));
 257         if (!tracepoint_dlopen.rcu_read_unlock_sym_bp)
 258                 tracepoint_dlopen.rcu_read_unlock_sym_bp =
 259                         URCU_FORCE_CAST(void (*)(void),
 260                                 dlsym(tracepoint_dlopen.liblttngust_handle,
 261                                         "tp_rcu_read_unlock_bp"));
 262         if (!tracepoint_dlopen.rcu_dereference_sym_bp)
 263                 tracepoint_dlopen.rcu_dereference_sym_bp =
 264                         URCU_FORCE_CAST(void *(*)(void *p),
 265                                 dlsym(tracepoint_dlopen.liblttngust_handle,
 266                                         "tp_rcu_dereference_sym_bp"));
 267 }
 268 #else
 269 static inline void lttng_ust_notrace
 270 __tracepoint__init_urcu_sym(void);
 271 static inline void
 272 __tracepoint__init_urcu_sym(void)
 273 {
 274 }
 275 #endif
 276
 277 static void lttng_ust_notrace __attribute__((constructor))
 278 __tracepoints__init(void);
 279 static void
 280 __tracepoints__init(void)
 281 {
 282         if (__tracepoint_registered++)
 283                 return;
 284
 285         if (!tracepoint_dlopen.liblttngust_handle)
 286                 tracepoint_dlopen.liblttngust_handle =
 287                         dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
 288         if (!tracepoint_dlopen.liblttngust_handle)
 289                 return;
 290         __tracepoint__init_urcu_sym();
 291 }
 292
 293 static void lttng_ust_notrace __attribute__((destructor))
 294 __tracepoints__destroy(void);
 295 static void
 296 __tracepoints__destroy(void)
 297 {
 298         int ret;
 299
 300         if (--__tracepoint_registered)
 301                 return;
 302         if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_ptrs_registered) {
 303                 ret = dlclose(tracepoint_dlopen.liblttngust_handle);
 304                 if (ret) {
 305                         fprintf(stderr, "Error (%d) in dlclose\n", ret);
 306                         abort();
 307                 }
 308                 memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
 309         }
 310 }
 311
 312 #endif
 313
 314 #ifdef TRACEPOINT_DEFINE
 315
 316 /*
 317  * These weak symbols, the constructor, and destructor take care of
 318  * registering only _one_ instance of the tracepoints per shared-ojbect
 319  * (or for the whole main program).
 320  */
 321 extern struct lttng_ust_tracepoint * const __start___tracepoints_ptrs[]
 322         __attribute__((weak, visibility("hidden")));
 323 extern struct lttng_ust_tracepoint * const __stop___tracepoints_ptrs[]
 324         __attribute__((weak, visibility("hidden")));
 325
 326 /*
 327  * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
 328  * unresolved symbol that requires the provider to be linked in. When
 329  * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
 330  * unresolved symbol that depends on having the provider linked in,
 331  * otherwise the linker complains. This deals with use of static
 332  * libraries, ensuring that the linker does not remove the provider
 333  * object from the executable.
 334  */
 335 #ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
 336 #define _TRACEPOINT_UNDEFINED_REF(provider)     NULL
 337 #else   /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
 338 #define _TRACEPOINT_UNDEFINED_REF(provider)     &__tracepoint_provider_##provider
 339 #endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
 340
 341 /*
 342  * Note: to allow PIC code, we need to allow the linker to update the pointers
 343  * in the __tracepoints_ptrs section.
 344  * Therefore, this section is _not_ const (read-only).
 345  */
 346 #define _TP_EXTRACT_STRING(...) #__VA_ARGS__
 347
 348 #define _DEFINE_TRACEPOINT(_provider, _name, _args)                             \
 349         extern int __tracepoint_provider_##_provider;                           \
 350         static const char __tp_strtab_##_provider##___##_name[]                 \
 351                 __attribute__((section("__tracepoints_strings"))) =             \
 352                         #_provider ":" #_name;                                  \
 353         struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name        \
 354                 __attribute__((section("__tracepoints"))) =                     \
 355                 {                                                               \
 356                         __tp_strtab_##_provider##___##_name,                    \
 357                         0,                                                      \
 358                         NULL,                                                   \
 359                         _TRACEPOINT_UNDEFINED_REF(_provider),                   \
 360                         _TP_EXTRACT_STRING(_args),                              \
 361                         { },                                                    \
 362                 };                                                              \
 363         static struct lttng_ust_tracepoint *                                    \
 364                 __tracepoint_ptr_##_provider##___##_name                        \
 365                 __attribute__((used, section("__tracepoints_ptrs"))) =          \
 366                         &__tracepoint_##_provider##___##_name;
 367
 368 static void lttng_ust_notrace __attribute__((constructor))
 369 __tracepoints__ptrs_init(void);
 370 static void
 371 __tracepoints__ptrs_init(void)
 372 {
 373         if (__tracepoint_ptrs_registered++)
 374                 return;
 375         if (!tracepoint_dlopen.liblttngust_handle)
 376                 tracepoint_dlopen.liblttngust_handle =
 377                         dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
 378         if (!tracepoint_dlopen.liblttngust_handle)
 379                 return;
 380         tracepoint_dlopen.tracepoint_register_lib =
 381                 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int),
 382                                 dlsym(tracepoint_dlopen.liblttngust_handle,
 383                                         "tracepoint_register_lib"));
 384         tracepoint_dlopen.tracepoint_unregister_lib =
 385                 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *),
 386                                 dlsym(tracepoint_dlopen.liblttngust_handle,
 387                                         "tracepoint_unregister_lib"));
 388         __tracepoint__init_urcu_sym();
 389         if (tracepoint_dlopen.tracepoint_register_lib) {
 390                 tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs,
 391                                 __stop___tracepoints_ptrs -
 392                                 __start___tracepoints_ptrs);
 393         }
 394 }
 395
 396 static void lttng_ust_notrace __attribute__((destructor))
 397 __tracepoints__ptrs_destroy(void);
 398 static void
 399 __tracepoints__ptrs_destroy(void)
 400 {
 401         int ret;
 402
 403         if (--__tracepoint_ptrs_registered)
 404                 return;
 405         if (tracepoint_dlopen.tracepoint_unregister_lib)
 406                 tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
 407         if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_registered) {
 408                 ret = dlclose(tracepoint_dlopen.liblttngust_handle);
 409                 if (ret) {
 410                         fprintf(stderr, "Error (%d) in dlclose\n", ret);
 411                         abort();
 412                 }
 413                 memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
 414         }
 415 }
 416
 417 #else /* TRACEPOINT_DEFINE */
 418
 419 #define _DEFINE_TRACEPOINT(_provider, _name, _args)
 420
 421 #endif /* #else TRACEPOINT_DEFINE */
 422
 423 #ifdef __cplusplus
 424 }
 425 #endif
 426
 427 #endif /* _LTTNG_TRACEPOINT_H */
 428
 429 /* The following declarations must be outside re-inclusion protection. */
 430
 431 #ifndef TRACEPOINT_EVENT
 432
 433 /*
 434  * How to use the TRACEPOINT_EVENT macro:
 435  *
 436  * An example:
 437  *
 438  * TRACEPOINT_EVENT(someproject_component, event_name,
 439  *
 440  *     * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
 441  *
 442  *     TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
 443  *             long *, arg4, size_t, arg4_len),
 444  *
 445  *      * TP_FIELDS describes the event payload layout in the trace *
 446  *
 447  *     TP_FIELDS(
 448  *         * Integer, printed in base 10 *
 449  *         ctf_integer(int, field_a, arg0)
 450  *
 451  *         * Integer, printed with 0x base 16 *
 452  *         ctf_integer_hex(unsigned long, field_d, arg1)
 453  *
 454  *         * Array Sequence, printed as UTF8-encoded array of bytes *
 455  *         ctf_array_text(char, field_b, string, FIXED_LEN)
 456  *         ctf_sequence_text(char, field_c, string, size_t, strlen)
 457  *
 458  *         * String, printed as UTF8-encoded string *
 459  *         ctf_string(field_e, string)
 460  *
 461  *         * Array sequence of signed integer values *
 462  *         ctf_array(long, field_f, arg4, FIXED_LEN4)
 463  *         ctf_sequence(long, field_g, arg4, size_t, arg4_len)
 464  *     )
 465  * )
 466  *
 467  * More detailed explanation:
 468  *
 469  * The name of the tracepoint is expressed as a tuple with the provider
 470  * and name arguments.
 471  *
 472  * The provider and name should be a proper C99 identifier.
 473  * The "provider" and "name" MUST follow these rules to ensure no
 474  * namespace clash occurs:
 475  *
 476  * For projects (applications and libraries) for which an entity
 477  * specific to the project controls the source code and thus its
 478  * tracepoints (typically with a scope larger than a single company):
 479  *
 480  * either:
 481  *   project_component, event
 482  * or:
 483  *   project, event
 484  *
 485  * Where "project" is the name of the project,
 486  *       "component" is the name of the project component (which may
 487  *       include several levels of sub-components, e.g.
 488  *       ...component_subcomponent_...) where the tracepoint is located
 489  *       (optional),
 490  *       "event" is the name of the tracepoint event.
 491  *
 492  * For projects issued from a single company wishing to advertise that
 493  * the company controls the source code and thus the tracepoints, the
 494  * "com_" prefix should be used:
 495  *
 496  * either:
 497  *   com_company_project_component, event
 498  * or:
 499  *   com_company_project, event
 500  *
 501  * Where "company" is the name of the company,
 502  *       "project" is the name of the project,
 503  *       "component" is the name of the project component (which may
 504  *       include several levels of sub-components, e.g.
 505  *       ...component_subcomponent_...) where the tracepoint is located
 506  *       (optional),
 507  *       "event" is the name of the tracepoint event.
 508  *
 509  * the provider:event identifier is limited to 127 characters.
 510  */
 511
 512 #define TRACEPOINT_EVENT(provider, name, args, fields)                  \
 513         _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))           \
 514         _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
 515
 516 #define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
 517
 518 #define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args)      \
 519         _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))           \
 520         _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
 521
 522 #endif /* #ifndef TRACEPOINT_EVENT */
 523
 524 #ifndef TRACEPOINT_LOGLEVEL
 525
 526 /*
 527  * Tracepoint Loglevels
 528  *
 529  * Typical use of these loglevels:
 530  *
 531  * The loglevels go from 0 to 14. Higher numbers imply the most
 532  * verbosity (higher event throughput expected.
 533  *
 534  * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
 535  * semantic. Loglevels 7 through 13 offer more fine-grained selection of
 536  * debug information.
 537  *
 538  * TRACE_EMERG           0
 539  * system is unusable
 540  *
 541  * TRACE_ALERT           1
 542  * action must be taken immediately
 543  *
 544  * TRACE_CRIT            2
 545  * critical conditions
 546  *
 547  * TRACE_ERR             3
 548  * error conditions
 549  *
 550  * TRACE_WARNING         4
 551  * warning conditions
 552  *
 553  * TRACE_NOTICE          5
 554  * normal, but significant, condition
 555  *
 556  * TRACE_INFO            6
 557  * informational message
 558  *
 559  * TRACE_DEBUG_SYSTEM    7
 560  * debug information with system-level scope (set of programs)
 561  *
 562  * TRACE_DEBUG_PROGRAM   8
 563  * debug information with program-level scope (set of processes)
 564  *
 565  * TRACE_DEBUG_PROCESS   9
 566  * debug information with process-level scope (set of modules)
 567  *
 568  * TRACE_DEBUG_MODULE    10
 569  * debug information with module (executable/library) scope (set of units)
 570  *
 571  * TRACE_DEBUG_UNIT      11
 572  * debug information with compilation unit scope (set of functions)
 573  *
 574  * TRACE_DEBUG_FUNCTION  12
 575  * debug information with function-level scope
 576  *
 577  * TRACE_DEBUG_LINE      13
 578  * debug information with line-level scope (TRACEPOINT_EVENT default)
 579  *
 580  * TRACE_DEBUG           14
 581  * debug-level message
 582  *
 583  * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
 584  * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
 585  * tracepoint name. The first field is the provider name, the second
 586  * field is the name of the tracepoint, the third field is the loglevel
 587  * name.
 588  *
 589  *      TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
 590  *              < loglevel_name >)
 591  *
 592  * The TRACEPOINT_PROVIDER must be already declared before declaring a
 593  * TRACEPOINT_LOGLEVEL.
 594  */
 595
 596 enum {
 597         TRACE_EMERG             = 0,
 598         TRACE_ALERT             = 1,
 599         TRACE_CRIT              = 2,
 600         TRACE_ERR               = 3,
 601         TRACE_WARNING           = 4,
 602         TRACE_NOTICE            = 5,
 603         TRACE_INFO              = 6,
 604         TRACE_DEBUG_SYSTEM      = 7,
 605         TRACE_DEBUG_PROGRAM     = 8,
 606         TRACE_DEBUG_PROCESS     = 9,
 607         TRACE_DEBUG_MODULE      = 10,
 608         TRACE_DEBUG_UNIT        = 11,
 609         TRACE_DEBUG_FUNCTION    = 12,
 610         TRACE_DEBUG_LINE        = 13,
 611         TRACE_DEBUG             = 14,
 612 };
 613
 614 #define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
 615
 616 #endif /* #ifndef TRACEPOINT_LOGLEVEL */
 617
 618 #ifndef TRACEPOINT_MODEL_EMF_URI
 619
 620 #define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
 621
 622 #endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */