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