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
  18 #include <lttng/tracepoint-types.h>
  19 #include <lttng/tracepoint-rcu.h>
  20 #include <urcu/compiler.h>
  21 #include <dlfcn.h>      /* for dlopen */
  22 #include <string.h>     /* for memset */
  23 #include <assert.h>
  24 #include <lttng/ust-config.h>   /* for sdt */
  25 #include <lttng/ust-compiler.h>
  26
  27 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
  28 #define SDT_USE_VARIADIC
  29 #include <sys/sdt.h>
  30 #else
  31 #define STAP_PROBEV(...)
  32 #endif
  33
  34 #ifdef __cplusplus
  35 extern "C" {
  36 #endif
  37
  38 #define tracepoint(provider, name, ...)                                     \
  39         do {                                                                \
  40                 TRACEPOINT_CALLSITE(provider, name);                        \
  41                 STAP_PROBEV(provider, name, ## __VA_ARGS__);                \
  42                 if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
  43                         __tracepoint_cb_##provider##___##name(__VA_ARGS__); \
  44         } while (0)
  45
  46 #define TP_ARGS(...)       __VA_ARGS__
  47
  48 /*
  49  * TP_ARGS takes tuples of type, argument separated by a comma.
  50  * It can take up to 10 tuples (which means that less than 10 tuples is
  51  * fine too).
  52  * Each tuple is also separated by a comma.
  53  */
  54 #define __TP_COMBINE_TOKENS(_tokena, _tokenb)                           \
  55                 _tokena##_tokenb
  56 #define _TP_COMBINE_TOKENS(_tokena, _tokenb)                            \
  57                 __TP_COMBINE_TOKENS(_tokena, _tokenb)
  58 #define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)                 \
  59                 _tokena##_tokenb##_tokenc
  60 #define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)                  \
  61                 __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
  62 #define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)        \
  63                 _tokena##_tokenb##_tokenc##_tokend
  64 #define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)         \
  65                 __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
  66
  67 /*
  68  * _TP_EXVAR* extract the var names.
  69  * _TP_EXVAR1 and _TP_EXDATA_VAR1 are needed for -std=c99.
  70  */
  71 #define _TP_EXVAR0()
  72 #define _TP_EXVAR1(a)
  73 #define _TP_EXVAR2(a,b)                                         b
  74 #define _TP_EXVAR4(a,b,c,d)                                     b,d
  75 #define _TP_EXVAR6(a,b,c,d,e,f)                                 b,d,f
  76 #define _TP_EXVAR8(a,b,c,d,e,f,g,h)                             b,d,f,h
  77 #define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j)                        b,d,f,h,j
  78 #define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l)                    b,d,f,h,j,l
  79 #define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n)                b,d,f,h,j,l,n
  80 #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
  81 #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
  82 #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
  83
  84 #define _TP_EXDATA_VAR0()                                               __tp_data
  85 #define _TP_EXDATA_VAR1(a)                                              __tp_data
  86 #define _TP_EXDATA_VAR2(a,b)                                            __tp_data,b
  87 #define _TP_EXDATA_VAR4(a,b,c,d)                                        __tp_data,b,d
  88 #define _TP_EXDATA_VAR6(a,b,c,d,e,f)                                    __tp_data,b,d,f
  89 #define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h)                                __tp_data,b,d,f,h
  90 #define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j)                           __tp_data,b,d,f,h,j
  91 #define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l)                       __tp_data,b,d,f,h,j,l
  92 #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
  93 #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
  94 #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
  95 #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
  96
  97 /*
  98  * _TP_EXPROTO* extract tuples of type, var.
  99  * _TP_EXPROTO1 and _TP_EXDATA_PROTO1 are needed for -std=c99.
 100  */
 101 #define _TP_EXPROTO0()                                          void
 102 #define _TP_EXPROTO1(a)                                         void
 103 #define _TP_EXPROTO2(a,b)                                       a b
 104 #define _TP_EXPROTO4(a,b,c,d)                                   a b,c d
 105 #define _TP_EXPROTO6(a,b,c,d,e,f)                               a b,c d,e f
 106 #define _TP_EXPROTO8(a,b,c,d,e,f,g,h)                           a b,c d,e f,g h
 107 #define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j)                      a b,c d,e f,g h,i j
 108 #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
 109 #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
 110 #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
 111 #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
 112 #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
 113
 114 #define _TP_EXDATA_PROTO0()                                             void *__tp_data
 115 #define _TP_EXDATA_PROTO1(a)                                            void *__tp_data
 116 #define _TP_EXDATA_PROTO2(a,b)                                          void *__tp_data,a b
 117 #define _TP_EXDATA_PROTO4(a,b,c,d)                                      void *__tp_data,a b,c d
 118 #define _TP_EXDATA_PROTO6(a,b,c,d,e,f)                                  void *__tp_data,a b,c d,e f
 119 #define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h)                              void *__tp_data,a b,c d,e f,g h
 120 #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
 121 #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
 122 #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
 123 #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
 124 #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
 125 #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
 126
 127 /* Preprocessor trick to count arguments. Inspired from sdt.h. */
 128 #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)
 129 #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
 130 #define _TP_PROTO_N(N, ...)             _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
 131 #define _TP_VAR_N(N, ...)               _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
 132 #define _TP_DATA_PROTO_N(N, ...)        _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
 133 #define _TP_DATA_VAR_N(N, ...)          _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
 134 #define _TP_ARGS_PROTO(...)             _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 135 #define _TP_ARGS_VAR(...)               _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 136 #define _TP_ARGS_DATA_PROTO(...)        _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 137 #define _TP_ARGS_DATA_VAR(...)          _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 138 #define _TP_PARAMS(...)                 __VA_ARGS__
 139
 140 #define _DECLARE_TRACEPOINT(_provider, _name, ...)                                      \
 141 extern struct tracepoint __tracepoint_##_provider##___##_name;                          \
 142 static inline lttng_ust_notrace                                                         \
 143 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__));              \
 144 static inline                                                                           \
 145 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__))               \
 146 {                                                                                       \
 147         struct tracepoint_probe *__tp_probe;                                            \
 148                                                                                         \
 149         if (!TP_RCU_LINK_TEST())                                                        \
 150                 return;                                                                 \
 151         tp_rcu_read_lock_bp();                                                          \
 152         __tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
 153         if (caa_unlikely(!__tp_probe))                                                  \
 154                 goto end;                                                               \
 155         do {                                                                            \
 156                 void (*__tp_cb)(void) = __tp_probe->func;                                       \
 157                 void *__tp_data = __tp_probe->data;                                     \
 158                                                                                         \
 159                 URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb)    \
 160                                 (_TP_ARGS_DATA_VAR(__VA_ARGS__));                       \
 161         } while ((++__tp_probe)->func);                                                 \
 162 end:                                                                                    \
 163         tp_rcu_read_unlock_bp();                                                        \
 164 }                                                                                       \
 165 static inline lttng_ust_notrace                                                         \
 166 void __tracepoint_register_##_provider##___##_name(char *name,                          \
 167                 void (*func)(void), void *data);                                        \
 168 static inline                                                                           \
 169 void __tracepoint_register_##_provider##___##_name(char *name,                          \
 170                 void (*func)(void), void *data)                                         \
 171 {                                                                                       \
 172         __tracepoint_probe_register(name, func, data,                                   \
 173                 __tracepoint_##_provider##___##_name.signature);                        \
 174 }                                                                                       \
 175 static inline lttng_ust_notrace                                                         \
 176 void __tracepoint_unregister_##_provider##___##_name(char *name,                        \
 177                 void (*func)(void), void *data);                                        \
 178 static inline                                                                           \
 179 void __tracepoint_unregister_##_provider##___##_name(char *name,                        \
 180                 void (*func)(void), void *data)                                         \
 181 {                                                                                       \
 182         __tracepoint_probe_unregister(name, func, data);                                \
 183 }
 184
 185 extern int __tracepoint_probe_register(const char *name, void (*func)(void),
 186                 void *data, const char *signature);
 187 extern int __tracepoint_probe_unregister(const char *name, void (*func)(void),
 188                 void *data);
 189
 190 /*
 191  * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
 192  * shared across objects in a module/main executable.
 193  */
 194 struct tracepoint_dlopen {
 195         void *liblttngust_handle;
 196
 197         int (*tracepoint_register_lib)(struct tracepoint * const *tracepoints_start,
 198                 int tracepoints_count);
 199         int (*tracepoint_unregister_lib)(struct tracepoint * const *tracepoints_start);
 200 #ifndef _LGPL_SOURCE
 201         void (*rcu_read_lock_sym_bp)(void);
 202         void (*rcu_read_unlock_sym_bp)(void);
 203         void *(*rcu_dereference_sym_bp)(void *p);
 204 #endif
 205 };
 206
 207 extern struct tracepoint_dlopen tracepoint_dlopen;
 208
 209 struct tracepoint_callsite_dlopen {
 210         void *liblttngust_handle;
 211
 212         int (*tracepoint_register_lib_callsite)(struct tracepoint_callsite * const *tp_start,
 213                 int tp_count);
 214         int (*tracepoint_unregister_lib_callsite)(struct tracepoint_callsite * const *tp_start,
 215                 int tp_count);
 216 };
 217
 218 struct tracepoint_callsite_dlopen tracepoint_callsite_dlopen
 219         __attribute__((weak, visibility("hidden")));
 220 int __tracepoint_callsite_registered
 221         __attribute__((weak, visibility("hidden")));
 222
 223 #if (CAA_BITS_PER_LONG == 64)
 224 #define __TP_ASM_PTR    ".quad "
 225 #else
 226 #define __TP_ASM_PTR    ".long "
 227 #endif
 228
 229 /*
 230  * Note: to allow PIC code, we need to allow the linker to update the pointers
 231  * in the __tracepoints_callsite_ptrs section.
 232  * Therefore, this section is _not_ const (read-only).
 233  */
 234 #define TRACEPOINT_CALLSITE(_provider, _name)                                   \
 235 do {                                                                            \
 236         asm volatile (  ".pushsection __tracepoint_callsite, \"aw\"\n\t"        \
 237                         "1:\n\t"                                                \
 238                         __TP_ASM_PTR "%c0, %c1, %c2, 2f\n\t"                    \
 239                         ".int %c3\n\t"                                          \
 240                         ".space 16\n\t" /* padding */                           \
 241                         ".popsection\n\t"                                       \
 242                         ".pushsection __tracepoint_callsite_ptrs, \"aw\"\n\t"   \
 243                         __TP_ASM_PTR "1b\n\t"                                   \
 244                         ".popsection\n\t"                                       \
 245                         "2:\n\t"                                                \
 246                 : : "i" (#_provider ":" #_name),                                \
 247                         "i" (__func__),                                         \
 248                         "i" (__FILE__),                                         \
 249                         "i" (__LINE__));                                        \
 250 } while (0)
 251
 252 /*
 253  * These weak symbols, the constructor, and destructor take care of
 254  * registering only _one_ instance of the tracepoint callsite per
 255  * shared-ojbect (or for the whole main program).
 256  */
 257 extern struct tracepoint_callsite * const __start___tracepoint_callsite_ptrs[]
 258         __attribute__((weak, visibility("hidden")));
 259 extern struct tracepoint_callsite * const __stop___tracepoint_callsite_ptrs[]
 260         __attribute__((weak, visibility("hidden")));
 261
 262 /*
 263  * We need at least one pointer in the section.
 264  */
 265 static struct tracepoint_callsite *
 266         __tracepoint_callsite_ptr_dummy
 267         __attribute__((used, section("__tracepoint_callsite_ptrs"))) =
 268                 NULL;
 269
 270 static void lttng_ust_notrace __attribute__((constructor))
 271 __tracepoint_callsite__init(void);
 272 static void
 273 __tracepoint_callsite__init(void)
 274 {
 275         if (__tracepoint_callsite_registered++)
 276                 return;
 277
 278         tracepoint_callsite_dlopen.liblttngust_handle =
 279                 dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
 280         if (!tracepoint_callsite_dlopen.liblttngust_handle)
 281                 return;
 282         tracepoint_callsite_dlopen.tracepoint_register_lib_callsite =
 283                 URCU_FORCE_CAST(int (*)(struct tracepoint_callsite * const *, int),
 284                                 dlsym(tracepoint_callsite_dlopen.liblttngust_handle,
 285                                         "tracepoint_register_lib_callsite"));
 286         tracepoint_callsite_dlopen.tracepoint_unregister_lib_callsite =
 287                 URCU_FORCE_CAST(int (*)(struct tracepoint_callsite * const *, int),
 288                                 dlsym(tracepoint_callsite_dlopen.liblttngust_handle,
 289                                         "tracepoint_unregister_lib_callsite"));
 290         tracepoint_callsite_dlopen.tracepoint_register_lib_callsite(__start___tracepoint_callsite_ptrs,
 291                                 __stop___tracepoint_callsite_ptrs -
 292                                 __start___tracepoint_callsite_ptrs);
 293 }
 294
 295 static void lttng_ust_notrace __attribute__((destructor))
 296 __tracepoint_callsite__destroy(void);
 297 static void
 298 __tracepoint_callsite__destroy(void)
 299 {
 300         int ret;
 301
 302         if (--__tracepoint_callsite_registered)
 303                 return;
 304         if (tracepoint_callsite_dlopen.tracepoint_unregister_lib_callsite)
 305                 tracepoint_callsite_dlopen.tracepoint_unregister_lib_callsite(__start___tracepoint_callsite_ptrs,
 306                                 __stop___tracepoint_callsite_ptrs -
 307                                 __start___tracepoint_callsite_ptrs);
 308         if (tracepoint_callsite_dlopen.liblttngust_handle) {
 309                 ret = dlclose(tracepoint_callsite_dlopen.liblttngust_handle);
 310                 assert(!ret);
 311                 memset(&tracepoint_callsite_dlopen, 0, sizeof(tracepoint_callsite_dlopen));
 312         }
 313 }
 314
 315 #ifdef TRACEPOINT_DEFINE
 316
 317 /*
 318  * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
 319  * unresolved symbol that requires the provider to be linked in. When
 320  * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
 321  * unresolved symbol that depends on having the provider linked in,
 322  * otherwise the linker complains. This deals with use of static
 323  * libraries, ensuring that the linker does not remove the provider
 324  * object from the executable.
 325  */
 326 #ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
 327 #define _TRACEPOINT_UNDEFINED_REF(provider)     NULL
 328 #else   /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
 329 #define _TRACEPOINT_UNDEFINED_REF(provider)     &__tracepoint_provider_##provider
 330 #endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
 331
 332 /*
 333  * Note: to allow PIC code, we need to allow the linker to update the pointers
 334  * in the __tracepoints_ptrs section.
 335  * Therefore, this section is _not_ const (read-only).
 336  */
 337 #define _TP_EXTRACT_STRING(...) #__VA_ARGS__
 338
 339 #define _DEFINE_TRACEPOINT(_provider, _name, _args)                             \
 340         extern int __tracepoint_provider_##_provider;                           \
 341         static const char __tp_strtab_##_provider##___##_name[]                 \
 342                 __attribute__((section("__tracepoints_strings"))) =             \
 343                         #_provider ":" #_name;                                  \
 344         struct tracepoint __tracepoint_##_provider##___##_name                  \
 345                 __attribute__((section("__tracepoints"))) =                     \
 346                 {                                                               \
 347                         __tp_strtab_##_provider##___##_name,                    \
 348                         0,                                                      \
 349                         NULL,                                                   \
 350                         _TRACEPOINT_UNDEFINED_REF(_provider),                   \
 351                         _TP_EXTRACT_STRING(_args),                              \
 352                 };                                                              \
 353         static struct tracepoint * __tracepoint_ptr_##_provider##___##_name     \
 354                 __attribute__((used, section("__tracepoints_ptrs"))) =          \
 355                         &__tracepoint_##_provider##___##_name;
 356
 357 /*
 358  * These weak symbols, the constructor, and destructor take care of
 359  * registering only _one_ instance of the tracepoints per shared-ojbect
 360  * (or for the whole main program).
 361  */
 362 extern struct tracepoint * const __start___tracepoints_ptrs[]
 363         __attribute__((weak, visibility("hidden")));
 364 extern struct tracepoint * const __stop___tracepoints_ptrs[]
 365         __attribute__((weak, visibility("hidden")));
 366 int __tracepoint_registered
 367         __attribute__((weak, visibility("hidden")));
 368 struct tracepoint_dlopen tracepoint_dlopen
 369         __attribute__((weak, visibility("hidden")));
 370
 371 static void lttng_ust_notrace __attribute__((constructor))
 372 __tracepoints__init(void);
 373 static void
 374 __tracepoints__init(void)
 375 {
 376         if (__tracepoint_registered++)
 377                 return;
 378
 379         tracepoint_dlopen.liblttngust_handle =
 380                 dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
 381         if (!tracepoint_dlopen.liblttngust_handle)
 382                 return;
 383         tracepoint_dlopen.tracepoint_register_lib =
 384                 URCU_FORCE_CAST(int (*)(struct tracepoint * const *, int),
 385                                 dlsym(tracepoint_dlopen.liblttngust_handle,
 386                                         "tracepoint_register_lib"));
 387         tracepoint_dlopen.tracepoint_unregister_lib =
 388                 URCU_FORCE_CAST(int (*)(struct tracepoint * const *),
 389                                 dlsym(tracepoint_dlopen.liblttngust_handle,
 390                                         "tracepoint_unregister_lib"));
 391 #ifndef _LGPL_SOURCE
 392         tracepoint_dlopen.rcu_read_lock_sym_bp =
 393                 URCU_FORCE_CAST(void (*)(void),
 394                                 dlsym(tracepoint_dlopen.liblttngust_handle,
 395                                         "tp_rcu_read_lock_bp"));
 396         tracepoint_dlopen.rcu_read_unlock_sym_bp =
 397                 URCU_FORCE_CAST(void (*)(void),
 398                                 dlsym(tracepoint_dlopen.liblttngust_handle,
 399                                         "tp_rcu_read_unlock_bp"));
 400         tracepoint_dlopen.rcu_dereference_sym_bp =
 401                 URCU_FORCE_CAST(void *(*)(void *p),
 402                                 dlsym(tracepoint_dlopen.liblttngust_handle,
 403                                         "tp_rcu_dereference_sym_bp"));
 404 #endif
 405         tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs,
 406                                 __stop___tracepoints_ptrs -
 407                                 __start___tracepoints_ptrs);
 408 }
 409
 410 static void lttng_ust_notrace __attribute__((destructor))
 411 __tracepoints__destroy(void);
 412 static void
 413 __tracepoints__destroy(void)
 414 {
 415         int ret;
 416
 417         if (--__tracepoint_registered)
 418                 return;
 419         if (tracepoint_dlopen.tracepoint_unregister_lib)
 420                 tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
 421         if (tracepoint_dlopen.liblttngust_handle) {
 422                 ret = dlclose(tracepoint_dlopen.liblttngust_handle);
 423                 assert(!ret);
 424                 memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
 425         }
 426 }
 427
 428 #else /* TRACEPOINT_DEFINE */
 429
 430 #define _DEFINE_TRACEPOINT(_provider, _name, _args)
 431
 432 #endif /* #else TRACEPOINT_DEFINE */
 433
 434 #ifdef __cplusplus
 435 }
 436 #endif
 437
 438 #endif /* _LTTNG_TRACEPOINT_H */
 439
 440 /* The following declarations must be outside re-inclusion protection. */
 441
 442 #ifndef TRACEPOINT_EVENT
 443
 444 /*
 445  * How to use the TRACEPOINT_EVENT macro:
 446  *
 447  * An example:
 448  *
 449  * TRACEPOINT_EVENT(someproject_component, event_name,
 450  *
 451  *     * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
 452  *
 453  *     TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
 454  *             long *, arg4, size_t, arg4_len),
 455  *
 456  *      * TP_FIELDS describes the event payload layout in the trace *
 457  *
 458  *     TP_FIELDS(
 459  *         * Integer, printed in base 10 *
 460  *         ctf_integer(int, field_a, arg0)
 461  *
 462  *         * Integer, printed with 0x base 16 *
 463  *         ctf_integer_hex(unsigned long, field_d, arg1)
 464  *
 465  *         * Array Sequence, printed as UTF8-encoded array of bytes *
 466  *         ctf_array_text(char, field_b, string, FIXED_LEN)
 467  *         ctf_sequence_text(char, field_c, string, size_t, strlen)
 468  *
 469  *         * String, printed as UTF8-encoded string *
 470  *         ctf_string(field_e, string)
 471  *
 472  *         * Array sequence of signed integer values *
 473  *         ctf_array(long, field_f, arg4, FIXED_LEN4)
 474  *         ctf_sequence(long, field_g, arg4, size_t, arg4_len)
 475  *     )
 476  * )
 477  *
 478  * More detailed explanation:
 479  *
 480  * The name of the tracepoint is expressed as a tuple with the provider
 481  * and name arguments.
 482  *
 483  * The provider and name should be a proper C99 identifier.
 484  * The "provider" and "name" MUST follow these rules to ensure no
 485  * namespace clash occurs:
 486  *
 487  * For projects (applications and libraries) for which an entity
 488  * specific to the project controls the source code and thus its
 489  * tracepoints (typically with a scope larger than a single company):
 490  *
 491  * either:
 492  *   project_component, event
 493  * or:
 494  *   project, event
 495  *
 496  * Where "project" is the name of the project,
 497  *       "component" is the name of the project component (which may
 498  *       include several levels of sub-components, e.g.
 499  *       ...component_subcomponent_...) where the tracepoint is located
 500  *       (optional),
 501  *       "event" is the name of the tracepoint event.
 502  *
 503  * For projects issued from a single company wishing to advertise that
 504  * the company controls the source code and thus the tracepoints, the
 505  * "com_" prefix should be used:
 506  *
 507  * either:
 508  *   com_company_project_component, event
 509  * or:
 510  *   com_company_project, event
 511  *
 512  * Where "company" is the name of the company,
 513  *       "project" is the name of the project,
 514  *       "component" is the name of the project component (which may
 515  *       include several levels of sub-components, e.g.
 516  *       ...component_subcomponent_...) where the tracepoint is located
 517  *       (optional),
 518  *       "event" is the name of the tracepoint event.
 519  *
 520  * the provider:event identifier is limited to 127 characters.
 521  */
 522
 523 #define TRACEPOINT_EVENT(provider, name, args, fields)                  \
 524         _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))           \
 525         _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
 526
 527 #define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
 528
 529 #define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args)      \
 530         _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))           \
 531         _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
 532
 533 #endif /* #ifndef TRACEPOINT_EVENT */
 534
 535 #ifndef TRACEPOINT_LOGLEVEL
 536
 537 /*
 538  * Tracepoint Loglevels
 539  *
 540  * Typical use of these loglevels:
 541  *
 542  * The loglevels go from 0 to 14. Higher numbers imply the most
 543  * verbosity (higher event throughput expected.
 544  *
 545  * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
 546  * semantic. Loglevels 7 through 13 offer more fine-grained selection of
 547  * debug information.
 548  *
 549  * TRACE_EMERG           0
 550  * system is unusable
 551  *
 552  * TRACE_ALERT           1
 553  * action must be taken immediately
 554  *
 555  * TRACE_CRIT            2
 556  * critical conditions
 557  *
 558  * TRACE_ERR             3
 559  * error conditions
 560  *
 561  * TRACE_WARNING         4
 562  * warning conditions
 563  *
 564  * TRACE_NOTICE          5
 565  * normal, but significant, condition
 566  *
 567  * TRACE_INFO            6
 568  * informational message
 569  *
 570  * TRACE_DEBUG_SYSTEM    7
 571  * debug information with system-level scope (set of programs)
 572  *
 573  * TRACE_DEBUG_PROGRAM   8
 574  * debug information with program-level scope (set of processes)
 575  *
 576  * TRACE_DEBUG_PROCESS   9
 577  * debug information with process-level scope (set of modules)
 578  *
 579  * TRACE_DEBUG_MODULE    10
 580  * debug information with module (executable/library) scope (set of units)
 581  *
 582  * TRACE_DEBUG_UNIT      11
 583  * debug information with compilation unit scope (set of functions)
 584  *
 585  * TRACE_DEBUG_FUNCTION  12
 586  * debug information with function-level scope
 587  *
 588  * TRACE_DEBUG_LINE      13
 589  * debug information with line-level scope (TRACEPOINT_EVENT default)
 590  *
 591  * TRACE_DEBUG           14
 592  * debug-level message (trace_printf default)
 593  *
 594  * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
 595  * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
 596  * tracepoint name. The first field is the provider name, the second
 597  * field is the name of the tracepoint, the third field is the loglevel
 598  * name.
 599  *
 600  *      TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
 601  *              < loglevel_name >)
 602  *
 603  * The TRACEPOINT_PROVIDER must be already declared before declaring a
 604  * TRACEPOINT_LOGLEVEL.
 605  */
 606
 607 enum {
 608         TRACE_EMERG             = 0,
 609         TRACE_ALERT             = 1,
 610         TRACE_CRIT              = 2,
 611         TRACE_ERR               = 3,
 612         TRACE_WARNING           = 4,
 613         TRACE_NOTICE            = 5,
 614         TRACE_INFO              = 6,
 615         TRACE_DEBUG_SYSTEM      = 7,
 616         TRACE_DEBUG_PROGRAM     = 8,
 617         TRACE_DEBUG_PROCESS     = 9,
 618         TRACE_DEBUG_MODULE      = 10,
 619         TRACE_DEBUG_UNIT        = 11,
 620         TRACE_DEBUG_FUNCTION    = 12,
 621         TRACE_DEBUG_LINE        = 13,
 622         TRACE_DEBUG             = 14,
 623 };
 624
 625 #define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
 626
 627 #endif /* #ifndef TRACEPOINT_LOGLEVEL */
 628
 629 #ifndef TRACEPOINT_MODEL_EMF_URI
 630
 631 #define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
 632
 633 #endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */