include/lttng/tracepoint.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  */
   6
   7 #ifndef _LTTNG_UST_TRACEPOINT_H
   8 #define _LTTNG_UST_TRACEPOINT_H
   9
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <lttng/tracepoint-types.h>
  13 #include <lttng/tracepoint-rcu.h>
  14 #include <lttng/ust-utils.h>
  15 #include <sys/types.h>
  16 #include <unistd.h>
  17
  18 #include <urcu/compiler.h>
  19 #include <urcu/system.h>
  20 #include <dlfcn.h>      /* for dlopen */
  21 #include <string.h>     /* for memset */
  22 #include <stdbool.h>
  23
  24 #include <lttng/ust-config.h>   /* for sdt */
  25 #include <lttng/ust-compiler.h>
  26 #include <lttng/ust-tracer.h>
  27 #include <lttng/ust-api-compat.h>
  28
  29 #if (defined(__cplusplus) && (__cplusplus <= 199711L))
  30 #error "C++11 support is required to build tracepoints and providers as C++"
  31 #endif
  32
  33 #define LTTNG_UST_TRACEPOINT_NAME_LEN_MAX       256
  34
  35 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
  36 /*
  37  * Instead of using SDT_USE_VARIADIC from 'sys/sdt.h', use our own namespaced
  38  * macros since the instrumented application might already have included
  39  * 'sys/sdt.h' without variadic support.
  40  */
  41 #include <sys/sdt.h>
  42
  43 #define LTTNG_UST__SDT_NARG(...) \
  44         LTTNG_UST___SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0)
  45
  46 #define LTTNG_UST___SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N
  47
  48 #define LTTNG_UST__SDT_PROBE_N(provider, name, N, ...) \
  49         _SDT_PROBE(provider, name, N, (__VA_ARGS__))
  50
  51 #define LTTNG_UST_STAP_PROBEV(provider, name, ...) \
  52         LTTNG_UST__SDT_PROBE_N(provider, name, LTTNG_UST__SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__)
  53
  54 #else
  55 #define LTTNG_UST_STAP_PROBEV(...)
  56 #endif
  57
  58 #ifdef __cplusplus
  59 extern "C" {
  60 #endif
  61
  62 #define lttng_ust_tracepoint_enabled(provider, name)                            \
  63         caa_unlikely(CMM_LOAD_SHARED(lttng_ust_tracepoint_##provider##___##name.state))
  64
  65 #define lttng_ust_do_tracepoint(provider, name, ...)                            \
  66         lttng_ust_tracepoint_cb_##provider##___##name(__VA_ARGS__)
  67
  68 #define lttng_ust_tracepoint(provider, name, ...)                               \
  69         do {                                                                    \
  70                 LTTNG_UST_STAP_PROBEV(provider, name, ## __VA_ARGS__);          \
  71                 if (lttng_ust_tracepoint_enabled(provider, name))               \
  72                         lttng_ust_do_tracepoint(provider, name, __VA_ARGS__);   \
  73         } while (0)
  74
  75 #define LTTNG_UST_TP_ARGS(...)       __VA_ARGS__
  76
  77 /*
  78  * LTTNG_UST_TP_ARGS takes tuples of type, argument separated by a comma.
  79  * It can take up to 10 tuples (which means that less than 10 tuples is
  80  * fine too).
  81  * Each tuple is also separated by a comma.
  82  */
  83 #define LTTNG_UST___TP_COMBINE_TOKENS(_tokena, _tokenb)                         \
  84                 _tokena##_tokenb
  85 #define LTTNG_UST__TP_COMBINE_TOKENS(_tokena, _tokenb)                          \
  86                 LTTNG_UST___TP_COMBINE_TOKENS(_tokena, _tokenb)
  87 #define LTTNG_UST___TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)                       \
  88                 _tokena##_tokenb##_tokenc
  89 #define LTTNG_UST__TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)                        \
  90                 LTTNG_UST___TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
  91 #define LTTNG_UST___TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)      \
  92                 _tokena##_tokenb##_tokenc##_tokend
  93 #define LTTNG_UST__TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)               \
  94                 LTTNG_UST___TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
  95
  96 /*
  97  * LTTNG_UST__TP_EXVAR* extract the var names.
  98  * LTTNG_UST__TP_EXVAR1 and LTTNG_UST__TP_EXDATA_VAR1 are needed for -std=c99.
  99  */
 100 #define LTTNG_UST__TP_EXVAR0()
 101 #define LTTNG_UST__TP_EXVAR1(a)
 102 #define LTTNG_UST__TP_EXVAR2(a,b)                                               b
 103 #define LTTNG_UST__TP_EXVAR4(a,b,c,d)                                   b,d
 104 #define LTTNG_UST__TP_EXVAR6(a,b,c,d,e,f)                                       b,d,f
 105 #define LTTNG_UST__TP_EXVAR8(a,b,c,d,e,f,g,h)                           b,d,f,h
 106 #define LTTNG_UST__TP_EXVAR10(a,b,c,d,e,f,g,h,i,j)                      b,d,f,h,j
 107 #define LTTNG_UST__TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l)                  b,d,f,h,j,l
 108 #define LTTNG_UST__TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n)              b,d,f,h,j,l,n
 109 #define LTTNG_UST__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
 110 #define LTTNG_UST__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
 111 #define LTTNG_UST__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
 112
 113 #define LTTNG_UST__TP_EXDATA_VAR0()                                             __tp_data
 114 #define LTTNG_UST__TP_EXDATA_VAR1(a)                                            __tp_data
 115 #define LTTNG_UST__TP_EXDATA_VAR2(a,b)                                          __tp_data,b
 116 #define LTTNG_UST__TP_EXDATA_VAR4(a,b,c,d)                                      __tp_data,b,d
 117 #define LTTNG_UST__TP_EXDATA_VAR6(a,b,c,d,e,f)                                  __tp_data,b,d,f
 118 #define LTTNG_UST__TP_EXDATA_VAR8(a,b,c,d,e,f,g,h)                              __tp_data,b,d,f,h
 119 #define LTTNG_UST__TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j)                         __tp_data,b,d,f,h,j
 120 #define LTTNG_UST__TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l)                     __tp_data,b,d,f,h,j,l
 121 #define LTTNG_UST__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
 122 #define LTTNG_UST__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
 123 #define LTTNG_UST__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
 124 #define LTTNG_UST__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
 125
 126 /*
 127  * LTTNG_UST__TP_EXPROTO* extract tuples of type, var.
 128  * LTTNG_UST__TP_EXPROTO1 and LTTNG_UST__TP_EXDATA_PROTO1 are needed for -std=c99.
 129  */
 130 #define LTTNG_UST__TP_EXPROTO0()                                                void
 131 #define LTTNG_UST__TP_EXPROTO1(a)                                               void
 132 #define LTTNG_UST__TP_EXPROTO2(a,b)                                     a b
 133 #define LTTNG_UST__TP_EXPROTO4(a,b,c,d)                                 a b,c d
 134 #define LTTNG_UST__TP_EXPROTO6(a,b,c,d,e,f)                             a b,c d,e f
 135 #define LTTNG_UST__TP_EXPROTO8(a,b,c,d,e,f,g,h)                         a b,c d,e f,g h
 136 #define LTTNG_UST__TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j)                    a b,c d,e f,g h,i j
 137 #define LTTNG_UST__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
 138 #define LTTNG_UST__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
 139 #define LTTNG_UST__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
 140 #define LTTNG_UST__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
 141 #define LTTNG_UST__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
 142
 143 #define LTTNG_UST__TP_EXDATA_PROTO0()                                           void *__tp_data
 144 #define LTTNG_UST__TP_EXDATA_PROTO1(a)                                          void *__tp_data
 145 #define LTTNG_UST__TP_EXDATA_PROTO2(a,b)                                                void *__tp_data,a b
 146 #define LTTNG_UST__TP_EXDATA_PROTO4(a,b,c,d)                                    void *__tp_data,a b,c d
 147 #define LTTNG_UST__TP_EXDATA_PROTO6(a,b,c,d,e,f)                                        void *__tp_data,a b,c d,e f
 148 #define LTTNG_UST__TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h)                            void *__tp_data,a b,c d,e f,g h
 149 #define LTTNG_UST__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
 150 #define LTTNG_UST__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
 151 #define LTTNG_UST__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
 152 #define LTTNG_UST__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
 153 #define LTTNG_UST__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
 154 #define LTTNG_UST__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
 155
 156 /* Preprocessor trick to count arguments. Inspired from sdt.h. */
 157 #define LTTNG_UST__TP_NARGS(...)                LTTNG_UST___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)
 158 #define LTTNG_UST___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
 159 #define LTTNG_UST__TP_PROTO_N(N, ...)           LTTNG_UST__TP_PARAMS(LTTNG_UST__TP_COMBINE_TOKENS(LTTNG_UST__TP_EXPROTO, N)(__VA_ARGS__))
 160 #define LTTNG_UST__TP_VAR_N(N, ...)             LTTNG_UST__TP_PARAMS(LTTNG_UST__TP_COMBINE_TOKENS(LTTNG_UST__TP_EXVAR, N)(__VA_ARGS__))
 161 #define LTTNG_UST__TP_DATA_PROTO_N(N, ...)      LTTNG_UST__TP_PARAMS(LTTNG_UST__TP_COMBINE_TOKENS(LTTNG_UST__TP_EXDATA_PROTO, N)(__VA_ARGS__))
 162 #define LTTNG_UST__TP_DATA_VAR_N(N, ...)        LTTNG_UST__TP_PARAMS(LTTNG_UST__TP_COMBINE_TOKENS(LTTNG_UST__TP_EXDATA_VAR, N)(__VA_ARGS__))
 163 #define LTTNG_UST__TP_ARGS_PROTO(...)           LTTNG_UST__TP_PROTO_N(LTTNG_UST__TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 164 #define LTTNG_UST__TP_ARGS_VAR(...)             LTTNG_UST__TP_VAR_N(LTTNG_UST__TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 165 #define LTTNG_UST__TP_ARGS_DATA_PROTO(...)      LTTNG_UST__TP_DATA_PROTO_N(LTTNG_UST__TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 166 #define LTTNG_UST__TP_ARGS_DATA_VAR(...)        LTTNG_UST__TP_DATA_VAR_N(LTTNG_UST__TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 167 #define LTTNG_UST__TP_PARAMS(...)               __VA_ARGS__
 168
 169 /*
 170  * sizeof(#_provider) - 1 : length of the provider string (excluding \0).
 171  * sizeof(#_name) - 1     : length of the name string (excluding \0).
 172  * + 1                    : separator between provider and event name.
 173  *
 174  * Upper bound (inclusive) is LTTNG_UST_TRACEPOINT_NAME_LEN_MAX - 1 to
 175  * account for \0.
 176  *
 177  * The comparison is:
 178  *   left hand side:   sizeof(#_provider) - 1 + sizeof(#_name) - 1 + 1
 179  *   right hand side:  LTTNG_UST_TRACEPOINT_NAME_LEN_MAX - 1
 180  *   operator:         <=  (inclusive)
 181  * Simplified in the code below.
 182  */
 183 #define lttng_ust_tracepoint_validate_name_len(_provider, _name)                                                \
 184         lttng_ust_static_assert(sizeof(#_provider) + sizeof(#_name) <= LTTNG_UST_TRACEPOINT_NAME_LEN_MAX,       \
 185                 "Tracepoint name length is too long",                                                           \
 186                 Tracepoint_name_length_is_too_long)
 187
 188 /*
 189  * The tracepoint cb is marked always inline so we can distinguish
 190  * between caller's ip addresses within the probe using the return
 191  * address.
 192  */
 193 #define LTTNG_UST__DECLARE_TRACEPOINT(_provider, _name, ...)                                    \
 194 extern struct lttng_ust_tracepoint lttng_ust_tracepoint_##_provider##___##_name         \
 195                 LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY;                            \
 196 static inline                                                                           \
 197 void lttng_ust_tracepoint_cb_##_provider##___##_name(LTTNG_UST__TP_ARGS_PROTO(__VA_ARGS__))             \
 198         __attribute__((always_inline, unused)) lttng_ust_notrace;                       \
 199 static                                                                                  \
 200 void lttng_ust_tracepoint_cb_##_provider##___##_name(LTTNG_UST__TP_ARGS_PROTO(__VA_ARGS__))             \
 201 {                                                                                       \
 202         struct lttng_ust_tracepoint_probe *__tp_probe;                                  \
 203                                                                                         \
 204         if (caa_unlikely(!LTTNG_UST_TP_RCU_LINK_TEST()))                                                \
 205                 return;                                                                 \
 206         lttng_ust_tp_rcu_read_lock();                                                           \
 207         __tp_probe = lttng_ust_tp_rcu_dereference(lttng_ust_tracepoint_##_provider##___##_name.probes); \
 208         if (caa_unlikely(!__tp_probe))                                                  \
 209                 goto end;                                                               \
 210         do {                                                                            \
 211                 void (*__tp_cb)(void) = __tp_probe->func;                               \
 212                 void *__tp_data = __tp_probe->data;                                     \
 213                                                                                         \
 214                 URCU_FORCE_CAST(void (*)(LTTNG_UST__TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb)  \
 215                                 (LTTNG_UST__TP_ARGS_DATA_VAR(__VA_ARGS__));                     \
 216         } while ((++__tp_probe)->func);                                                 \
 217 end:                                                                                    \
 218         lttng_ust_tp_rcu_read_unlock();                                                         \
 219 }                                                                                       \
 220 static inline                                                                           \
 221 void lttng_ust_tracepoint_register_##_provider##___##_name(char *provider_name, char *event_name, \
 222                 void (*func)(void), void *data)                                         \
 223         lttng_ust_notrace;                                                              \
 224 static inline                                                                           \
 225 void lttng_ust_tracepoint_register_##_provider##___##_name(char *provider_name, char *event_name, \
 226                 void (*func)(void), void *data)                                         \
 227 {                                                                                       \
 228         lttng_ust_tracepoint_provider_register(provider_name, event_name, func, data,           \
 229                 lttng_ust_tracepoint_##_provider##___##_name.signature);                        \
 230 }                                                                                       \
 231 static inline                                                                           \
 232 void lttng_ust_tracepoint_unregister_##_provider##___##_name(char *provider_name, char *event_name, \
 233                 void (*func)(void), void *data)                                         \
 234         lttng_ust_notrace;                                                              \
 235 static inline                                                                           \
 236 void lttng_ust_tracepoint_unregister_##_provider##___##_name(char *provider_name, char *event_name, \
 237                 void (*func)(void), void *data)                                         \
 238 {                                                                                       \
 239         lttng_ust_tracepoint_provider_unregister(provider_name, event_name, func, data);                \
 240 }
 241
 242 /*
 243  * Registration of tracepoint provider probe functions with
 244  * lttng_ust_tracepoint_provider_register, unregistration with
 245  * lttng_ust_tracepoint_provider_unregister.
 246  */
 247 int lttng_ust_tracepoint_provider_register(const char *provider_name, const char *event_name,
 248                 void (*func)(void), void *data, const char *signature);
 249 int lttng_ust_tracepoint_provider_unregister(const char *provider_name, const char *event_name,
 250                 void (*func)(void), void *data);
 251
 252 /*
 253  * Registration of tracepoint instrumentation modules with lttng_ust_tracepoint_module_register,
 254  * unregistration with lttng_ust_tracepoint_module_unregister.
 255  */
 256 int lttng_ust_tracepoint_module_register(struct lttng_ust_tracepoint * const *tracepoints_start,
 257                              int tracepoints_count);
 258 int lttng_ust_tracepoint_module_unregister(struct lttng_ust_tracepoint * const *tracepoints_start);
 259
 260 /*
 261  * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
 262  * shared across objects in a module/main executable.
 263  *
 264  * IMPORTANT: this structure is part of the ABI between instrumented
 265  * applications and UST. Fields need to be only added at the end, never
 266  * reordered, never removed.
 267  *
 268  * The field @struct_size should be used to determine the size of the
 269  * structure. It should be queried before using additional fields added
 270  * at the end of the structure.
 271  */
 272 struct lttng_ust_tracepoint_dlopen {
 273         uint32_t struct_size;
 274
 275         void *liblttngust_handle;
 276
 277         int (*lttng_ust_tracepoint_module_register)(struct lttng_ust_tracepoint * const *tracepoints_start,
 278                 int tracepoints_count);
 279         int (*lttng_ust_tracepoint_module_unregister)(struct lttng_ust_tracepoint * const *tracepoints_start);
 280         void (*rcu_read_lock_sym)(void);
 281         void (*rcu_read_unlock_sym)(void);
 282         void *(*rcu_dereference_sym)(void *p);
 283
 284         /* End of base ABI. Fields below should be used after checking struct_size. */
 285 };
 286
 287 extern struct lttng_ust_tracepoint_dlopen lttng_ust_tracepoint_dlopen;
 288 extern struct lttng_ust_tracepoint_dlopen *lttng_ust_tracepoint_dlopen_ptr;
 289
 290 /*
 291  * These weak symbols, the constructor, and destructor take care of
 292  * registering only _one_ instance of the tracepoints per shared-ojbect
 293  * (or for the whole main program).
 294  */
 295 int lttng_ust_tracepoint_registered
 296         __attribute__((weak, visibility("hidden")));
 297 int lttng_ust_tracepoint_ptrs_registered
 298         __attribute__((weak, visibility("hidden")));
 299 struct lttng_ust_tracepoint_dlopen lttng_ust_tracepoint_dlopen
 300                 __attribute__((weak, visibility("hidden"))) = {
 301         .struct_size = sizeof(struct lttng_ust_tracepoint_dlopen),
 302 };
 303 /*
 304  * Deal with gcc O1 optimisation issues with weak hidden symbols. gcc
 305  * 4.8 and prior does not have the same behavior for symbol scoping on
 306  * 32-bit powerpc depending on the object size: symbols for objects of 8
 307  * bytes or less have the same address throughout a module, whereas they
 308  * have different addresses between compile units for objects larger
 309  * than 8 bytes. Add this pointer indirection to ensure that the symbol
 310  * scoping match that of the other weak hidden symbols found in this
 311  * header.
 312  */
 313 struct lttng_ust_tracepoint_dlopen *lttng_ust_tracepoint_dlopen_ptr
 314         __attribute__((weak, visibility("hidden")));
 315
 316 /*
 317  * Tracepoint dynamic linkage handling (callbacks). Hidden visibility: shared
 318  * across objects in a module/main executable. The callbacks are used to
 319  * control and check if the destructors should be executed.
 320  *
 321  * IMPORTANT: this structure is part of the ABI between instrumented
 322  * applications and UST. Fields need to be only added at the end, never
 323  * reordered, never removed.
 324  *
 325  * The field @struct_size should be used to determine the size of the
 326  * structure. It should be queried before using additional fields added
 327  * at the end of the structure.
 328  */
 329 struct lttng_ust_tracepoint_destructors_syms {
 330         uint32_t struct_size;
 331
 332         void (*tracepoint_disable_destructors)(void);
 333         int (*tracepoint_get_destructors_state)(void);
 334
 335         /* End of base ABI. Fields below should be used after checking struct_size. */
 336 };
 337
 338 extern struct lttng_ust_tracepoint_destructors_syms lttng_ust_tracepoint_destructors_syms;
 339 extern struct lttng_ust_tracepoint_destructors_syms *lttng_ust_tracepoint_destructors_syms_ptr;
 340
 341 struct lttng_ust_tracepoint_destructors_syms lttng_ust_tracepoint_destructors_syms
 342         __attribute__((weak, visibility("hidden"))) = {
 343         .struct_size = sizeof(struct lttng_ust_tracepoint_destructors_syms),
 344 };
 345 struct lttng_ust_tracepoint_destructors_syms *lttng_ust_tracepoint_destructors_syms_ptr
 346         __attribute__((weak, visibility("hidden")));
 347
 348 static inline void tracepoint_disable_destructors(void)
 349 {
 350         if (!lttng_ust_tracepoint_dlopen_ptr)
 351                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 352         if (!lttng_ust_tracepoint_destructors_syms_ptr)
 353                 lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 354         if (lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle
 355                         && lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_disable_destructors)
 356                 lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_disable_destructors();
 357 }
 358
 359 #ifndef _LGPL_SOURCE
 360 static inline void
 361 lttng_ust_tracepoint__init_urcu_sym(void)
 362         lttng_ust_notrace;
 363 static inline void
 364 lttng_ust_tracepoint__init_urcu_sym(void)
 365 {
 366         if (!lttng_ust_tracepoint_dlopen_ptr)
 367                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 368         /*
 369          * Symbols below are needed by tracepoint call sites and probe
 370          * providers.
 371          */
 372         if (!lttng_ust_tracepoint_dlopen_ptr->rcu_read_lock_sym)
 373                 lttng_ust_tracepoint_dlopen_ptr->rcu_read_lock_sym =
 374                         URCU_FORCE_CAST(void (*)(void),
 375                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 376                                         "lttng_ust_tp_rcu_read_lock"));
 377         if (!lttng_ust_tracepoint_dlopen_ptr->rcu_read_unlock_sym)
 378                 lttng_ust_tracepoint_dlopen_ptr->rcu_read_unlock_sym =
 379                         URCU_FORCE_CAST(void (*)(void),
 380                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 381                                         "lttng_ust_tp_rcu_read_unlock"));
 382         if (!lttng_ust_tracepoint_dlopen_ptr->rcu_dereference_sym)
 383                 lttng_ust_tracepoint_dlopen_ptr->rcu_dereference_sym =
 384                         URCU_FORCE_CAST(void *(*)(void *p),
 385                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 386                                         "lttng_ust_tp_rcu_dereference_sym"));
 387 }
 388 #else
 389 static inline void
 390 lttng_ust_tracepoint__init_urcu_sym(void)
 391         lttng_ust_notrace;
 392 static inline void
 393 lttng_ust_tracepoint__init_urcu_sym(void)
 394 {
 395 }
 396 #endif
 397
 398 /*
 399  * Use getenv() directly and bypass lttng-ust helper functions
 400  * because we may not have access to lttng-ust shared libraries.
 401  */
 402 #ifdef LTTNG_UST_DEBUG
 403 static inline
 404 bool lttng_ust_tracepoint_logging_debug_enabled(void)
 405 {
 406         return true;
 407 }
 408 #else /* #ifdef LTTNG_UST_DEBUG */
 409 static inline
 410 bool lttng_ust_tracepoint_logging_debug_enabled(void)
 411 {
 412         return getenv("LTTNG_UST_DEBUG");
 413 }
 414 #endif /* #ifdef LTTNG_UST_DEBUG */
 415
 416 #define LTTNG_UST_TRACEPOINT_THIS_IP            \
 417         ({ __label__ here; here: &&here; })
 418
 419 static void
 420 lttng_ust_tracepoints_print_disabled_message(void)
 421 {
 422         if (!lttng_ust_tracepoint_logging_debug_enabled())
 423                 return;
 424         fprintf(stderr, "lttng-ust-tracepoint [%ld]: dlopen() failed to find '%s', tracepoints in this binary won't be registered. "
 425                 "(at addr=%p in %s() at " __FILE__ ":" lttng_ust_stringify(__LINE__) ")\n",
 426                 (long) getpid(),
 427                 LTTNG_UST_TRACEPOINT_LIB_SONAME,
 428                 LTTNG_UST_TRACEPOINT_THIS_IP,
 429                 __func__);
 430 }
 431
 432 static void
 433 lttng_ust__tracepoints__init(void)
 434         lttng_ust_notrace __attribute__((constructor));
 435 static void
 436 lttng_ust__tracepoints__init(void)
 437 {
 438         if (lttng_ust_tracepoint_registered++) {
 439                 if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 440                         return;
 441                 lttng_ust_tracepoint__init_urcu_sym();
 442                 return;
 443         }
 444
 445         if (!lttng_ust_tracepoint_dlopen_ptr)
 446                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 447         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 448                 lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle =
 449                         dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
 450         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle) {
 451                 lttng_ust_tracepoints_print_disabled_message();
 452                 return;
 453         }
 454         lttng_ust_tracepoint__init_urcu_sym();
 455 }
 456
 457 static void
 458 lttng_ust__tracepoints__destroy(void)
 459         lttng_ust_notrace __attribute__((destructor));
 460 static void
 461 lttng_ust__tracepoints__destroy(void)
 462 {
 463         int ret;
 464
 465         if (--lttng_ust_tracepoint_registered)
 466                 return;
 467         if (!lttng_ust_tracepoint_dlopen_ptr)
 468                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 469         if (!lttng_ust_tracepoint_destructors_syms_ptr)
 470                 lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 471         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 472                 return;
 473         if (lttng_ust_tracepoint_ptrs_registered)
 474                 return;
 475         /*
 476          * Lookup if destructors must be executed using the new method.
 477          */
 478         if (lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
 479                 && !lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()) {
 480                 /*
 481                  * The tracepoint_get_destructors_state symbol was found with
 482                  * dlsym but its returned value is 0 meaning that destructors
 483                  * must not be executed.
 484                  */
 485                 return;
 486         }
 487         ret = dlclose(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle);
 488         if (ret) {
 489                 fprintf(stderr, "Error (%d) in dlclose\n", ret);
 490                 abort();
 491         }
 492         memset(lttng_ust_tracepoint_dlopen_ptr, 0, sizeof(*lttng_ust_tracepoint_dlopen_ptr));
 493 }
 494
 495 #if LTTNG_UST_COMPAT_API(0)
 496 # if defined(TRACEPOINT_DEFINE) && !defined(LTTNG_UST_TRACEPOINT_DEFINE)
 497 #  define LTTNG_UST_TRACEPOINT_DEFINE
 498 # endif
 499 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 500
 501 #ifdef LTTNG_UST_TRACEPOINT_DEFINE
 502
 503 /*
 504  * These weak symbols, the constructor, and destructor take care of
 505  * registering only _one_ instance of the tracepoints per shared-ojbect
 506  * (or for the whole main program).
 507  */
 508 extern struct lttng_ust_tracepoint * const __start_lttng_ust_tracepoints_ptrs[]
 509         __attribute__((weak, visibility("hidden")));
 510 extern struct lttng_ust_tracepoint * const __stop_lttng_ust_tracepoints_ptrs[]
 511         __attribute__((weak, visibility("hidden")));
 512
 513 /*
 514  * When LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
 515  * unresolved symbol that requires the provider to be linked in. When
 516  * LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
 517  * unresolved symbol that depends on having the provider linked in,
 518  * otherwise the linker complains. This deals with use of static
 519  * libraries, ensuring that the linker does not remove the provider
 520  * object from the executable.
 521  */
 522
 523 #if LTTNG_UST_COMPAT_API(0)
 524 # if defined(TRACEPOINT_PROBE_DYNAMIC_LINKAGE) && !defined(LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE)
 525 #  define LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE
 526 # endif
 527 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 528
 529 #ifdef LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE
 530 #define LTTNG_UST__TRACEPOINT_UNDEFINED_REF(provider)   NULL
 531 #else   /* LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
 532 #define LTTNG_UST__TRACEPOINT_UNDEFINED_REF(provider)   &lttng_ust_tracepoint_provider_##provider
 533 #endif /* LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
 534
 535 /*
 536  * Note: to allow PIC code, we need to allow the linker to update the pointers
 537  * in the lttng_ust_tracepoints_ptrs section.
 538  * Therefore, this section is _not_ const (read-only).
 539  */
 540 #define LTTNG_UST__TP_EXTRACT_STRING(...)       #__VA_ARGS__
 541
 542 #define LTTNG_UST__DEFINE_TRACEPOINT(_provider, _name, _args)                           \
 543         lttng_ust_tracepoint_validate_name_len(_provider, _name);               \
 544         extern int lttng_ust_tracepoint_provider_##_provider                    \
 545                 LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY;           \
 546         static const char lttng_ust_tp_provider_strtab_##_provider##___##_name[]        \
 547                 __attribute__((section("lttng_ust_tracepoints_strings"))) =             \
 548                         #_provider;                                             \
 549         static const char lttng_ust_tp_name_strtab_##_provider##___##_name[]            \
 550                 __attribute__((section("lttng_ust_tracepoints_strings"))) =             \
 551                         #_name;                                                 \
 552         struct lttng_ust_tracepoint lttng_ust_tracepoint_##_provider##___##_name        \
 553                 __attribute__((section("lttng_ust_tracepoints")))               \
 554                 LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY = {                 \
 555                         sizeof(struct lttng_ust_tracepoint),                    \
 556                         lttng_ust_tp_provider_strtab_##_provider##___##_name,           \
 557                         lttng_ust_tp_name_strtab_##_provider##___##_name,               \
 558                         0,                                                      \
 559                         NULL,                                                   \
 560                         LTTNG_UST__TRACEPOINT_UNDEFINED_REF(_provider),         \
 561                         LTTNG_UST__TP_EXTRACT_STRING(_args),                    \
 562                 };                                                              \
 563         static struct lttng_ust_tracepoint *                                    \
 564                 lttng_ust_tracepoint_ptr_##_provider##___##_name                        \
 565                 __attribute__((section("lttng_ust_tracepoints_ptrs"), used))            \
 566                 __lttng_ust_variable_attribute_no_sanitize_address =            \
 567                         &lttng_ust_tracepoint_##_provider##___##_name;
 568
 569 static void
 570 lttng_ust__tracepoints__ptrs_init(void)
 571         lttng_ust_notrace __attribute__((constructor));
 572 static void
 573 lttng_ust__tracepoints__ptrs_init(void)
 574 {
 575         if (lttng_ust_tracepoint_ptrs_registered++)
 576                 return;
 577         if (!lttng_ust_tracepoint_dlopen_ptr)
 578                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 579         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 580                 lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle =
 581                         dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
 582         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle) {
 583                 lttng_ust_tracepoints_print_disabled_message();
 584                 return;
 585         }
 586         if (!lttng_ust_tracepoint_destructors_syms_ptr)
 587                 lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 588         lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_register =
 589                 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int),
 590                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 591                                         "lttng_ust_tracepoint_module_register"));
 592         lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_unregister =
 593                 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *),
 594                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 595                                         "lttng_ust_tracepoint_module_unregister"));
 596         lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_disable_destructors =
 597                 URCU_FORCE_CAST(void (*)(void),
 598                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 599                                         "lttng_ust_tp_disable_destructors"));
 600         lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state =
 601                 URCU_FORCE_CAST(int (*)(void),
 602                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 603                                         "lttng_ust_tp_get_destructors_state"));
 604         lttng_ust_tracepoint__init_urcu_sym();
 605         if (lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_register) {
 606                 lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_register(__start_lttng_ust_tracepoints_ptrs,
 607                                 __stop_lttng_ust_tracepoints_ptrs -
 608                                 __start_lttng_ust_tracepoints_ptrs);
 609         }
 610 }
 611
 612 static void
 613 lttng_ust__tracepoints__ptrs_destroy(void)
 614         lttng_ust_notrace __attribute__((destructor));
 615 static void
 616 lttng_ust__tracepoints__ptrs_destroy(void)
 617 {
 618         int ret;
 619
 620         if (--lttng_ust_tracepoint_ptrs_registered)
 621                 return;
 622         if (!lttng_ust_tracepoint_dlopen_ptr)
 623                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 624         if (!lttng_ust_tracepoint_destructors_syms_ptr)
 625                 lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 626         if (lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_unregister)
 627                 lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_unregister(__start_lttng_ust_tracepoints_ptrs);
 628         if (lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle
 629                         && lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
 630                         && lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()
 631                         && !lttng_ust_tracepoint_ptrs_registered) {
 632                 ret = dlclose(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle);
 633                 if (ret) {
 634                         fprintf(stderr, "Error (%d) in dlclose\n", ret);
 635                         abort();
 636                 }
 637                 memset(lttng_ust_tracepoint_dlopen_ptr, 0, sizeof(*lttng_ust_tracepoint_dlopen_ptr));
 638         }
 639 }
 640
 641 #else /* LTTNG_UST_TRACEPOINT_DEFINE */
 642
 643 #define LTTNG_UST__DEFINE_TRACEPOINT(_provider, _name, _args)
 644
 645 #endif /* #else LTTNG_UST_TRACEPOINT_DEFINE */
 646
 647 #if LTTNG_UST_COMPAT_API(0)
 648 #define tracepoint                      lttng_ust_tracepoint
 649 #define do_tracepoint                   lttng_ust_do_tracepoint
 650 #define tracepoint_enabled              lttng_ust_tracepoint_enabled
 651 #define TP_ARGS                         LTTNG_UST_TP_ARGS
 652 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 653
 654 #ifdef __cplusplus
 655 }
 656 #endif
 657
 658 #endif /* _LTTNG_UST_TRACEPOINT_H */
 659
 660 /* The following declarations must be outside re-inclusion protection. */
 661
 662 /*
 663  * LTTNG_UST_TRACEPOINT_HIDDEN_DEFINITION: Define this before including
 664  * a tracepoint instrumentation header to hide symbols associated with
 665  * tracepoint module instrumentation. This is useful if all compile
 666  * units using the lttng_ust_tracepoint(),
 667  * lttng_ust_tracepoint_enabled() and lttng_ust_do_tracepoint() macros
 668  * is within the same module as the compile unit including the
 669  * tracepoint header after defining LTTNG_UST_TRACEPOINT_DEFINE.
 670  */
 671
 672 #undef LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY
 673 #ifdef LTTNG_UST_TRACEPOINT_HIDDEN_DEFINITION
 674 #define LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY             __attribute__((visibility("hidden")))
 675 #else
 676 #define LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY             __attribute__((visibility("default")))
 677 #endif
 678
 679 /*
 680  * LTTNG_UST_TRACEPOINT_PROVIDER_HIDDEN_DEFINITION: Define this before
 681  * including a tracepoint instrumentation header to hide symbols
 682  * associated with the tracepoint provider. This is useful if the
 683  * tracepoint definition (including the header after defining
 684  * LTTNG_UST_TRACEPOINT_DEFINE) is in the same module as the provider
 685  * (including the header after defining
 686  * LTTNG_UST_TRACEPOINT_CREATE_PROBES).
 687  */
 688 #undef LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY
 689 #ifdef LTTNG_UST_TRACEPOINT_PROVIDER_HIDDEN_DEFINITION
 690 #define LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY    __attribute__((visibility("hidden")))
 691 #else
 692 #define LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY    __attribute__((visibility("default")))
 693 #endif
 694
 695 #ifndef LTTNG_UST_TRACEPOINT_ENUM
 696
 697 /*
 698  * Tracepoint Enumerations
 699  *
 700  * The enumeration is a mapping between an integer, or range of integers, and
 701  * a string. It can be used to have a more compact trace in cases where the
 702  * possible values for a field are limited:
 703  *
 704  * An example:
 705  *
 706  * LTTNG_UST_TRACEPOINT_ENUM(someproject_component, enumname,
 707  *      LTTNG_UST_TP_ENUM_VALUES(
 708  *              lttng_ust_field_enum_value("even", 0)
 709  *              lttng_ust_field_enum_value("uneven", 1)
 710  *              lttng_ust_field_enum_range("twoto4", 2, 4)
 711  *              lttng_ust_field_enum_value("five", 5)
 712  *      )
 713  * )
 714  *
 715  * Where "someproject_component" is the name of the component this enumeration
 716  * belongs to and "enumname" identifies this enumeration. Inside the
 717  * LTTNG_UST_TP_ENUM_VALUES macro is the actual mapping. Each string value can map
 718  * to either a single value with lttng_ust_field_enum_value or a range of values
 719  * with lttng_ust_field_enum_range.
 720  *
 721  * Enumeration ranges may overlap, but the behavior is implementation-defined,
 722  * each trace reader will handle overlapping as it wishes.
 723  *
 724  * That enumeration can then be used in a field inside the TP_FIELD macro using
 725  * the following line:
 726  *
 727  * lttng_ust_field_enum(someproject_component, enumname, enumtype, enumfield, enumval)
 728  *
 729  * Where "someproject_component" and "enumname" match those in the
 730  * LTTNG_UST_TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
 731  * backing the enumeration, "enumfield" is the name of the field and
 732  * "enumval" is the value.
 733  */
 734
 735 #define LTTNG_UST_TRACEPOINT_ENUM(provider, name, values)
 736
 737 #if LTTNG_UST_COMPAT_API(0)
 738 #define TRACEPOINT_ENUM         LTTNG_UST_TRACEPOINT_ENUM
 739 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 740
 741 #endif /* #ifndef LTTNG_UST_TRACEPOINT_ENUM */
 742
 743 #ifndef LTTNG_UST_TRACEPOINT_EVENT
 744
 745 /*
 746  * How to use the LTTNG_UST_TRACEPOINT_EVENT macro:
 747  *
 748  * An example:
 749  *
 750  * LTTNG_UST_TRACEPOINT_EVENT(someproject_component, event_name,
 751  *
 752  *     * LTTNG_UST_TP_ARGS takes from 0 to 10 "type, field_name" pairs *
 753  *
 754  *     LTTNG_UST_TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
 755  *             long *, arg4, size_t, arg4_len),
 756  *
 757  *      * LTTNG_UST_TP_FIELDS describes the event payload layout in the trace *
 758  *
 759  *     LTTNG_UST_TP_FIELDS(
 760  *         * Integer, printed in base 10 *
 761  *         lttng_ust_field_integer(int, field_a, arg0)
 762  *
 763  *         * Integer, printed with 0x base 16 *
 764  *         lttng_ust_field_integer_hex(unsigned long, field_d, arg1)
 765  *
 766  *         * Enumeration *
 767  *         lttng_ust_field_enum(someproject_component, enum_name, int, field_e, arg0)
 768  *
 769  *         * Array Sequence, printed as UTF8-encoded array of bytes *
 770  *         lttng_ust_field_array_text(char, field_b, string, FIXED_LEN)
 771  *         lttng_ust_field_sequence_text(char, field_c, string, size_t, strlen)
 772  *
 773  *         * String, printed as UTF8-encoded string *
 774  *         lttng_ust_field_string(field_e, string)
 775  *
 776  *         * Array sequence of signed integer values *
 777  *         lttng_ust_field_array(long, field_f, arg4, FIXED_LEN4)
 778  *         lttng_ust_field_sequence(long, field_g, arg4, size_t, arg4_len)
 779  *     )
 780  * )
 781  *
 782  * More detailed explanation:
 783  *
 784  * The name of the tracepoint is expressed as a tuple with the provider
 785  * and name arguments.
 786  *
 787  * The provider and name should be a proper C99 identifier.
 788  * The "provider" and "name" MUST follow these rules to ensure no
 789  * namespace clash occurs:
 790  *
 791  * For projects (applications and libraries) for which an entity
 792  * specific to the project controls the source code and thus its
 793  * tracepoints (typically with a scope larger than a single company):
 794  *
 795  * either:
 796  *   project_component, event
 797  * or:
 798  *   project, event
 799  *
 800  * Where "project" is the name of the project,
 801  *       "component" is the name of the project component (which may
 802  *       include several levels of sub-components, e.g.
 803  *       ...component_subcomponent_...) where the tracepoint is located
 804  *       (optional),
 805  *       "event" is the name of the tracepoint event.
 806  *
 807  * For projects issued from a single company wishing to advertise that
 808  * the company controls the source code and thus the tracepoints, the
 809  * "com_" prefix should be used:
 810  *
 811  * either:
 812  *   com_company_project_component, event
 813  * or:
 814  *   com_company_project, event
 815  *
 816  * Where "company" is the name of the company,
 817  *       "project" is the name of the project,
 818  *       "component" is the name of the project component (which may
 819  *       include several levels of sub-components, e.g.
 820  *       ...component_subcomponent_...) where the tracepoint is located
 821  *       (optional),
 822  *       "event" is the name of the tracepoint event.
 823  *
 824  * the provider:event identifier is limited to 127 characters.
 825  */
 826
 827 #define LTTNG_UST_TRACEPOINT_EVENT(provider, name, args, fields)                        \
 828         LTTNG_UST__DECLARE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))               \
 829         LTTNG_UST__DEFINE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))
 830
 831 #define LTTNG_UST_TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
 832
 833 #define LTTNG_UST_TRACEPOINT_EVENT_INSTANCE(template_provider, template_name, provider, name, args)     \
 834         LTTNG_UST__DECLARE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))               \
 835         LTTNG_UST__DEFINE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))
 836
 837 #if LTTNG_UST_COMPAT_API(0)
 838 #define TRACEPOINT_EVENT                LTTNG_UST_TRACEPOINT_EVENT
 839 #define TRACEPOINT_EVENT_CLASS          LTTNG_UST_TRACEPOINT_EVENT_CLASS
 840 #define TRACEPOINT_EVENT_INSTANCE(_provider, _template, _name, args)    \
 841         LTTNG_UST_TRACEPOINT_EVENT_INSTANCE(_provider, _template,       \
 842                 _provider, _name, LTTNG_UST__TP_PARAMS(args))
 843
 844 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 845
 846 #endif /* #ifndef LTTNG_UST_TRACEPOINT_EVENT */
 847
 848 #ifndef LTTNG_UST_TRACEPOINT_LOGLEVEL
 849
 850 /*
 851  * Tracepoint Loglevels
 852  *
 853  * Typical use of these loglevels:
 854  *
 855  * The loglevels go from 0 to 14. Higher numbers imply the most
 856  * verbosity (higher event throughput expected.
 857  *
 858  * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
 859  * semantic. Loglevels 7 through 13 offer more fine-grained selection of
 860  * debug information.
 861  *
 862  * LTTNG_UST_TRACEPOINT_LOGLEVEL_EMERG           0
 863  * system is unusable
 864  *
 865  * LTTNG_UST_TRACEPOINT_LOGLEVEL_ALERT           1
 866  * action must be taken immediately
 867  *
 868  * LTTNG_UST_TRACEPOINT_LOGLEVEL_CRIT            2
 869  * critical conditions
 870  *
 871  * LTTNG_UST_TRACEPOINT_LOGLEVEL_ERR             3
 872  * error conditions
 873  *
 874  * LTTNG_UST_TRACEPOINT_LOGLEVEL_WARNING         4
 875  * warning conditions
 876  *
 877  * LTTNG_UST_TRACEPOINT_LOGLEVEL_NOTICE          5
 878  * normal, but significant, condition
 879  *
 880  * LTTNG_UST_TRACEPOINT_LOGLEVEL_INFO            6
 881  * informational message
 882  *
 883  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_SYSTEM    7
 884  * debug information with system-level scope (set of programs)
 885  *
 886  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROGRAM   8
 887  * debug information with program-level scope (set of processes)
 888  *
 889  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROCESS   9
 890  * debug information with process-level scope (set of modules)
 891  *
 892  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_MODULE    10
 893  * debug information with module (executable/library) scope (set of units)
 894  *
 895  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_UNIT      11
 896  * debug information with compilation unit scope (set of functions)
 897  *
 898  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_FUNCTION  12
 899  * debug information with function-level scope
 900  *
 901  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_LINE      13
 902  * debug information with line-level scope (LTTNG_UST_TRACEPOINT_EVENT default)
 903  *
 904  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG           14
 905  * debug-level message
 906  *
 907  * Declare tracepoint loglevels for tracepoints. A LTTNG_UST_TRACEPOINT_EVENT
 908  * should be declared prior to the the LTTNG_UST_TRACEPOINT_LOGLEVEL for a given
 909  * tracepoint name. The first field is the provider name, the second
 910  * field is the name of the tracepoint, the third field is the loglevel
 911  * name.
 912  *
 913  *      LTTNG_UST_TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
 914  *              < loglevel_name >)
 915  *
 916  * The LTTNG_UST_TRACEPOINT_PROVIDER must be already declared before declaring a
 917  * LTTNG_UST_TRACEPOINT_LOGLEVEL.
 918  */
 919
 920 enum {
 921         LTTNG_UST_TRACEPOINT_LOGLEVEL_EMERG             = 0,
 922         LTTNG_UST_TRACEPOINT_LOGLEVEL_ALERT             = 1,
 923         LTTNG_UST_TRACEPOINT_LOGLEVEL_CRIT              = 2,
 924         LTTNG_UST_TRACEPOINT_LOGLEVEL_ERR               = 3,
 925         LTTNG_UST_TRACEPOINT_LOGLEVEL_WARNING           = 4,
 926         LTTNG_UST_TRACEPOINT_LOGLEVEL_NOTICE            = 5,
 927         LTTNG_UST_TRACEPOINT_LOGLEVEL_INFO              = 6,
 928         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_SYSTEM      = 7,
 929         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROGRAM     = 8,
 930         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROCESS     = 9,
 931         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_MODULE      = 10,
 932         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_UNIT        = 11,
 933         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_FUNCTION    = 12,
 934         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_LINE        = 13,
 935         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG             = 14,
 936 };
 937
 938 #define LTTNG_UST_TRACEPOINT_LOGLEVEL(provider, name, loglevel)
 939
 940 #if LTTNG_UST_COMPAT_API(0)
 941 #define TRACEPOINT_LOGLEVEL     LTTNG_UST_TRACEPOINT_LOGLEVEL
 942
 943 #define TRACE_EMERG             LTTNG_UST_TRACEPOINT_LOGLEVEL_EMERG
 944 #define TRACE_ALERT             LTTNG_UST_TRACEPOINT_LOGLEVEL_ALERT
 945 #define TRACE_CRIT              LTTNG_UST_TRACEPOINT_LOGLEVEL_CRIT
 946 #define TRACE_ERR               LTTNG_UST_TRACEPOINT_LOGLEVEL_ERR
 947 #define TRACE_WARNING           LTTNG_UST_TRACEPOINT_LOGLEVEL_WARNING
 948 #define TRACE_NOTICE            LTTNG_UST_TRACEPOINT_LOGLEVEL_NOTICE
 949 #define TRACE_INFO              LTTNG_UST_TRACEPOINT_LOGLEVEL_INFO
 950 #define TRACE_DEBUG_SYSTEM      LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_SYSTEM
 951 #define TRACE_DEBUG_PROGRAM     LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROGRAM
 952 #define TRACE_DEBUG_PROCESS     LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROCESS
 953 #define TRACE_DEBUG_MODULE      LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_MODULE
 954 #define TRACE_DEBUG_UNIT        LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_UNIT
 955 #define TRACE_DEBUG_FUNCTION    LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_FUNCTION
 956 #define TRACE_DEBUG_LINE        LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_LINE
 957 #define TRACE_DEBUG             LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG
 958 #endif
 959
 960 #endif /* #ifndef LTTNG_UST_TRACEPOINT_LOGLEVEL */
 961
 962 #ifndef LTTNG_UST_TRACEPOINT_MODEL_EMF_URI
 963
 964 #define LTTNG_UST_TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
 965
 966 #if LTTNG_UST_COMPAT_API(0)
 967 #define TRACEPOINT_MODEL_EMF_URI LTTNG_UST_TRACEPOINT_MODEL_EMF_URI
 968 #endif
 969
 970 #endif /* #ifndef LTTNG_UST_TRACEPOINT_MODEL_EMF_URI */