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 #ifdef LTTNG_UST_ABORT_ON_CRITICAL
 417 static inline
 418 bool lttng_ust_tracepoint_logging_abort_on_critical_enabled(void)
 419 {
 420         return true;
 421 }
 422 #else /* #ifdef LTTNG_UST_ABORT_ON_CRITICAL */
 423 static inline
 424 bool lttng_ust_tracepoint_logging_abort_on_critical_enabled(void)
 425 {
 426         return getenv("LTTNG_UST_ABORT_ON_CRITICAL");
 427 }
 428 #endif
 429
 430 #define LTTNG_UST_TRACEPOINT_THIS_IP            \
 431         ({ __label__ here; here: &&here; })
 432
 433 static void
 434 lttng_ust_tracepoints_print_disabled_message(void)
 435 {
 436         if (lttng_ust_tracepoint_logging_debug_enabled())
 437                 fprintf(stderr, "lttng-ust-tracepoint [%ld]: Critical: dlopen() failed to find '%s', tracepoints in this binary won't be registered. "
 438                         "(at addr=%p in %s() at " __FILE__ ":" lttng_ust_stringify(__LINE__) ")\n",
 439                         (long) getpid(),
 440                         LTTNG_UST_TRACEPOINT_LIB_SONAME,
 441                         LTTNG_UST_TRACEPOINT_THIS_IP,
 442                         __func__);
 443         if (lttng_ust_tracepoint_logging_abort_on_critical_enabled())
 444                 abort();
 445 }
 446
 447 static void
 448 lttng_ust__tracepoints__init(void)
 449         lttng_ust_notrace __attribute__((constructor));
 450 static void
 451 lttng_ust__tracepoints__init(void)
 452 {
 453         if (lttng_ust_tracepoint_registered++) {
 454                 if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 455                         return;
 456                 lttng_ust_tracepoint__init_urcu_sym();
 457                 return;
 458         }
 459
 460         if (!lttng_ust_tracepoint_dlopen_ptr)
 461                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 462         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 463                 lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle =
 464                         dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
 465         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle) {
 466                 lttng_ust_tracepoints_print_disabled_message();
 467                 return;
 468         }
 469         lttng_ust_tracepoint__init_urcu_sym();
 470 }
 471
 472 static void
 473 lttng_ust__tracepoints__destroy(void)
 474         lttng_ust_notrace __attribute__((destructor));
 475 static void
 476 lttng_ust__tracepoints__destroy(void)
 477 {
 478         int ret;
 479
 480         if (--lttng_ust_tracepoint_registered)
 481                 return;
 482         if (!lttng_ust_tracepoint_dlopen_ptr)
 483                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 484         if (!lttng_ust_tracepoint_destructors_syms_ptr)
 485                 lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 486         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 487                 return;
 488         if (lttng_ust_tracepoint_ptrs_registered)
 489                 return;
 490         /*
 491          * Lookup if destructors must be executed using the new method.
 492          */
 493         if (lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
 494                 && !lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()) {
 495                 /*
 496                  * The tracepoint_get_destructors_state symbol was found with
 497                  * dlsym but its returned value is 0 meaning that destructors
 498                  * must not be executed.
 499                  */
 500                 return;
 501         }
 502         ret = dlclose(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle);
 503         if (ret) {
 504                 fprintf(stderr, "Error (%d) in dlclose\n", ret);
 505                 abort();
 506         }
 507         memset(lttng_ust_tracepoint_dlopen_ptr, 0, sizeof(*lttng_ust_tracepoint_dlopen_ptr));
 508 }
 509
 510 #if LTTNG_UST_COMPAT_API(0)
 511 # if defined(TRACEPOINT_DEFINE) && !defined(LTTNG_UST_TRACEPOINT_DEFINE)
 512 #  define LTTNG_UST_TRACEPOINT_DEFINE
 513 # endif
 514 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 515
 516 #ifdef LTTNG_UST_TRACEPOINT_DEFINE
 517
 518 /*
 519  * These weak symbols, the constructor, and destructor take care of
 520  * registering only _one_ instance of the tracepoints per shared-ojbect
 521  * (or for the whole main program).
 522  */
 523 extern struct lttng_ust_tracepoint * const __start_lttng_ust_tracepoints_ptrs[]
 524         __attribute__((weak, visibility("hidden")));
 525 extern struct lttng_ust_tracepoint * const __stop_lttng_ust_tracepoints_ptrs[]
 526         __attribute__((weak, visibility("hidden")));
 527
 528 /*
 529  * When LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
 530  * unresolved symbol that requires the provider to be linked in. When
 531  * LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
 532  * unresolved symbol that depends on having the provider linked in,
 533  * otherwise the linker complains. This deals with use of static
 534  * libraries, ensuring that the linker does not remove the provider
 535  * object from the executable.
 536  */
 537
 538 #if LTTNG_UST_COMPAT_API(0)
 539 # if defined(TRACEPOINT_PROBE_DYNAMIC_LINKAGE) && !defined(LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE)
 540 #  define LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE
 541 # endif
 542 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 543
 544 #ifdef LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE
 545 #define LTTNG_UST__TRACEPOINT_UNDEFINED_REF(provider)   NULL
 546 #else   /* LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
 547 #define LTTNG_UST__TRACEPOINT_UNDEFINED_REF(provider)   &lttng_ust_tracepoint_provider_##provider
 548 #endif /* LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
 549
 550 /*
 551  * Note: to allow PIC code, we need to allow the linker to update the pointers
 552  * in the lttng_ust_tracepoints_ptrs section.
 553  * Therefore, this section is _not_ const (read-only).
 554  */
 555 #define LTTNG_UST__TP_EXTRACT_STRING(...)       #__VA_ARGS__
 556
 557 #define LTTNG_UST__DEFINE_TRACEPOINT(_provider, _name, _args)                           \
 558         lttng_ust_tracepoint_validate_name_len(_provider, _name);               \
 559         extern int lttng_ust_tracepoint_provider_##_provider                    \
 560                 LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY;           \
 561         static const char lttng_ust_tp_provider_strtab_##_provider##___##_name[]        \
 562                 __attribute__((section("lttng_ust_tracepoints_strings"))) =             \
 563                         #_provider;                                             \
 564         static const char lttng_ust_tp_name_strtab_##_provider##___##_name[]            \
 565                 __attribute__((section("lttng_ust_tracepoints_strings"))) =             \
 566                         #_name;                                                 \
 567         struct lttng_ust_tracepoint lttng_ust_tracepoint_##_provider##___##_name        \
 568                 __attribute__((section("lttng_ust_tracepoints")))               \
 569                 LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY = {                 \
 570                         sizeof(struct lttng_ust_tracepoint),                    \
 571                         lttng_ust_tp_provider_strtab_##_provider##___##_name,           \
 572                         lttng_ust_tp_name_strtab_##_provider##___##_name,               \
 573                         0,                                                      \
 574                         NULL,                                                   \
 575                         LTTNG_UST__TRACEPOINT_UNDEFINED_REF(_provider),         \
 576                         LTTNG_UST__TP_EXTRACT_STRING(_args),                    \
 577                 };                                                              \
 578         static struct lttng_ust_tracepoint *                                    \
 579                 lttng_ust_tracepoint_ptr_##_provider##___##_name                        \
 580                 __attribute__((section("lttng_ust_tracepoints_ptrs"), used))            \
 581                 __lttng_ust_variable_attribute_no_sanitize_address =            \
 582                         &lttng_ust_tracepoint_##_provider##___##_name;
 583
 584 static void
 585 lttng_ust__tracepoints__ptrs_init(void)
 586         lttng_ust_notrace __attribute__((constructor));
 587 static void
 588 lttng_ust__tracepoints__ptrs_init(void)
 589 {
 590         if (lttng_ust_tracepoint_ptrs_registered++)
 591                 return;
 592         if (!lttng_ust_tracepoint_dlopen_ptr)
 593                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 594         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 595                 lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle =
 596                         dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
 597         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle) {
 598                 lttng_ust_tracepoints_print_disabled_message();
 599                 return;
 600         }
 601         if (!lttng_ust_tracepoint_destructors_syms_ptr)
 602                 lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 603         lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_register =
 604                 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int),
 605                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 606                                         "lttng_ust_tracepoint_module_register"));
 607         lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_unregister =
 608                 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *),
 609                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 610                                         "lttng_ust_tracepoint_module_unregister"));
 611         lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_disable_destructors =
 612                 URCU_FORCE_CAST(void (*)(void),
 613                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 614                                         "lttng_ust_tp_disable_destructors"));
 615         lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state =
 616                 URCU_FORCE_CAST(int (*)(void),
 617                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 618                                         "lttng_ust_tp_get_destructors_state"));
 619         lttng_ust_tracepoint__init_urcu_sym();
 620         if (lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_register) {
 621                 lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_register(__start_lttng_ust_tracepoints_ptrs,
 622                                 __stop_lttng_ust_tracepoints_ptrs -
 623                                 __start_lttng_ust_tracepoints_ptrs);
 624         }
 625 }
 626
 627 static void
 628 lttng_ust__tracepoints__ptrs_destroy(void)
 629         lttng_ust_notrace __attribute__((destructor));
 630 static void
 631 lttng_ust__tracepoints__ptrs_destroy(void)
 632 {
 633         int ret;
 634
 635         if (--lttng_ust_tracepoint_ptrs_registered)
 636                 return;
 637         if (!lttng_ust_tracepoint_dlopen_ptr)
 638                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 639         if (!lttng_ust_tracepoint_destructors_syms_ptr)
 640                 lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 641         if (lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_unregister)
 642                 lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_unregister(__start_lttng_ust_tracepoints_ptrs);
 643         if (lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle
 644                         && lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
 645                         && lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()
 646                         && !lttng_ust_tracepoint_ptrs_registered) {
 647                 ret = dlclose(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle);
 648                 if (ret) {
 649                         fprintf(stderr, "Error (%d) in dlclose\n", ret);
 650                         abort();
 651                 }
 652                 memset(lttng_ust_tracepoint_dlopen_ptr, 0, sizeof(*lttng_ust_tracepoint_dlopen_ptr));
 653         }
 654 }
 655
 656 #else /* LTTNG_UST_TRACEPOINT_DEFINE */
 657
 658 #define LTTNG_UST__DEFINE_TRACEPOINT(_provider, _name, _args)
 659
 660 #endif /* #else LTTNG_UST_TRACEPOINT_DEFINE */
 661
 662 #if LTTNG_UST_COMPAT_API(0)
 663 #define tracepoint                      lttng_ust_tracepoint
 664 #define do_tracepoint                   lttng_ust_do_tracepoint
 665 #define tracepoint_enabled              lttng_ust_tracepoint_enabled
 666 #define TP_ARGS                         LTTNG_UST_TP_ARGS
 667 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 668
 669 #ifdef __cplusplus
 670 }
 671 #endif
 672
 673 #endif /* _LTTNG_UST_TRACEPOINT_H */
 674
 675 /* The following declarations must be outside re-inclusion protection. */
 676
 677 /*
 678  * LTTNG_UST_TRACEPOINT_HIDDEN_DEFINITION: Define this before including
 679  * a tracepoint instrumentation header to hide symbols associated with
 680  * tracepoint module instrumentation. This is useful if all compile
 681  * units using the lttng_ust_tracepoint(),
 682  * lttng_ust_tracepoint_enabled() and lttng_ust_do_tracepoint() macros
 683  * is within the same module as the compile unit including the
 684  * tracepoint header after defining LTTNG_UST_TRACEPOINT_DEFINE.
 685  */
 686
 687 #undef LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY
 688 #ifdef LTTNG_UST_TRACEPOINT_HIDDEN_DEFINITION
 689 #define LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY             __attribute__((visibility("hidden")))
 690 #else
 691 #define LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY             __attribute__((visibility("default")))
 692 #endif
 693
 694 /*
 695  * LTTNG_UST_TRACEPOINT_PROVIDER_HIDDEN_DEFINITION: Define this before
 696  * including a tracepoint instrumentation header to hide symbols
 697  * associated with the tracepoint provider. This is useful if the
 698  * tracepoint definition (including the header after defining
 699  * LTTNG_UST_TRACEPOINT_DEFINE) is in the same module as the provider
 700  * (including the header after defining
 701  * LTTNG_UST_TRACEPOINT_CREATE_PROBES).
 702  */
 703 #undef LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY
 704 #ifdef LTTNG_UST_TRACEPOINT_PROVIDER_HIDDEN_DEFINITION
 705 #define LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY    __attribute__((visibility("hidden")))
 706 #else
 707 #define LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY    __attribute__((visibility("default")))
 708 #endif
 709
 710 #ifndef LTTNG_UST_TRACEPOINT_ENUM
 711
 712 /*
 713  * Tracepoint Enumerations
 714  *
 715  * The enumeration is a mapping between an integer, or range of integers, and
 716  * a string. It can be used to have a more compact trace in cases where the
 717  * possible values for a field are limited:
 718  *
 719  * An example:
 720  *
 721  * LTTNG_UST_TRACEPOINT_ENUM(someproject_component, enumname,
 722  *      LTTNG_UST_TP_ENUM_VALUES(
 723  *              lttng_ust_field_enum_value("even", 0)
 724  *              lttng_ust_field_enum_value("uneven", 1)
 725  *              lttng_ust_field_enum_range("twoto4", 2, 4)
 726  *              lttng_ust_field_enum_value("five", 5)
 727  *      )
 728  * )
 729  *
 730  * Where "someproject_component" is the name of the component this enumeration
 731  * belongs to and "enumname" identifies this enumeration. Inside the
 732  * LTTNG_UST_TP_ENUM_VALUES macro is the actual mapping. Each string value can map
 733  * to either a single value with lttng_ust_field_enum_value or a range of values
 734  * with lttng_ust_field_enum_range.
 735  *
 736  * Enumeration ranges may overlap, but the behavior is implementation-defined,
 737  * each trace reader will handle overlapping as it wishes.
 738  *
 739  * That enumeration can then be used in a field inside the TP_FIELD macro using
 740  * the following line:
 741  *
 742  * lttng_ust_field_enum(someproject_component, enumname, enumtype, enumfield, enumval)
 743  *
 744  * Where "someproject_component" and "enumname" match those in the
 745  * LTTNG_UST_TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
 746  * backing the enumeration, "enumfield" is the name of the field and
 747  * "enumval" is the value.
 748  */
 749
 750 #define LTTNG_UST_TRACEPOINT_ENUM(provider, name, values)
 751
 752 #if LTTNG_UST_COMPAT_API(0)
 753 #define TRACEPOINT_ENUM         LTTNG_UST_TRACEPOINT_ENUM
 754 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 755
 756 #endif /* #ifndef LTTNG_UST_TRACEPOINT_ENUM */
 757
 758 #ifndef LTTNG_UST_TRACEPOINT_EVENT
 759
 760 /*
 761  * How to use the LTTNG_UST_TRACEPOINT_EVENT macro:
 762  *
 763  * An example:
 764  *
 765  * LTTNG_UST_TRACEPOINT_EVENT(someproject_component, event_name,
 766  *
 767  *     * LTTNG_UST_TP_ARGS takes from 0 to 10 "type, field_name" pairs *
 768  *
 769  *     LTTNG_UST_TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
 770  *             long *, arg4, size_t, arg4_len),
 771  *
 772  *      * LTTNG_UST_TP_FIELDS describes the event payload layout in the trace *
 773  *
 774  *     LTTNG_UST_TP_FIELDS(
 775  *         * Integer, printed in base 10 *
 776  *         lttng_ust_field_integer(int, field_a, arg0)
 777  *
 778  *         * Integer, printed with 0x base 16 *
 779  *         lttng_ust_field_integer_hex(unsigned long, field_d, arg1)
 780  *
 781  *         * Enumeration *
 782  *         lttng_ust_field_enum(someproject_component, enum_name, int, field_e, arg0)
 783  *
 784  *         * Array Sequence, printed as UTF8-encoded array of bytes *
 785  *         lttng_ust_field_array_text(char, field_b, string, FIXED_LEN)
 786  *         lttng_ust_field_sequence_text(char, field_c, string, size_t, strlen)
 787  *
 788  *         * String, printed as UTF8-encoded string *
 789  *         lttng_ust_field_string(field_e, string)
 790  *
 791  *         * Array sequence of signed integer values *
 792  *         lttng_ust_field_array(long, field_f, arg4, FIXED_LEN4)
 793  *         lttng_ust_field_sequence(long, field_g, arg4, size_t, arg4_len)
 794  *     )
 795  * )
 796  *
 797  * More detailed explanation:
 798  *
 799  * The name of the tracepoint is expressed as a tuple with the provider
 800  * and name arguments.
 801  *
 802  * The provider and name should be a proper C99 identifier.
 803  * The "provider" and "name" MUST follow these rules to ensure no
 804  * namespace clash occurs:
 805  *
 806  * For projects (applications and libraries) for which an entity
 807  * specific to the project controls the source code and thus its
 808  * tracepoints (typically with a scope larger than a single company):
 809  *
 810  * either:
 811  *   project_component, event
 812  * or:
 813  *   project, event
 814  *
 815  * Where "project" is the name of the project,
 816  *       "component" is the name of the project component (which may
 817  *       include several levels of sub-components, e.g.
 818  *       ...component_subcomponent_...) where the tracepoint is located
 819  *       (optional),
 820  *       "event" is the name of the tracepoint event.
 821  *
 822  * For projects issued from a single company wishing to advertise that
 823  * the company controls the source code and thus the tracepoints, the
 824  * "com_" prefix should be used:
 825  *
 826  * either:
 827  *   com_company_project_component, event
 828  * or:
 829  *   com_company_project, event
 830  *
 831  * Where "company" is the name of the company,
 832  *       "project" is the name of the project,
 833  *       "component" is the name of the project component (which may
 834  *       include several levels of sub-components, e.g.
 835  *       ...component_subcomponent_...) where the tracepoint is located
 836  *       (optional),
 837  *       "event" is the name of the tracepoint event.
 838  *
 839  * the provider:event identifier is limited to 127 characters.
 840  */
 841
 842 #define LTTNG_UST_TRACEPOINT_EVENT(provider, name, args, fields)                        \
 843         LTTNG_UST__DECLARE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))               \
 844         LTTNG_UST__DEFINE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))
 845
 846 #define LTTNG_UST_TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
 847
 848 #define LTTNG_UST_TRACEPOINT_EVENT_INSTANCE(template_provider, template_name, provider, name, args)     \
 849         LTTNG_UST__DECLARE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))               \
 850         LTTNG_UST__DEFINE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))
 851
 852 #if LTTNG_UST_COMPAT_API(0)
 853 #define TRACEPOINT_EVENT                LTTNG_UST_TRACEPOINT_EVENT
 854 #define TRACEPOINT_EVENT_CLASS          LTTNG_UST_TRACEPOINT_EVENT_CLASS
 855 #define TRACEPOINT_EVENT_INSTANCE(_provider, _template, _name, args)    \
 856         LTTNG_UST_TRACEPOINT_EVENT_INSTANCE(_provider, _template,       \
 857                 _provider, _name, LTTNG_UST__TP_PARAMS(args))
 858
 859 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 860
 861 #endif /* #ifndef LTTNG_UST_TRACEPOINT_EVENT */
 862
 863 #ifndef LTTNG_UST_TRACEPOINT_LOGLEVEL
 864
 865 /*
 866  * Tracepoint Loglevels
 867  *
 868  * Typical use of these loglevels:
 869  *
 870  * The loglevels go from 0 to 14. Higher numbers imply the most
 871  * verbosity (higher event throughput expected.
 872  *
 873  * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
 874  * semantic. Loglevels 7 through 13 offer more fine-grained selection of
 875  * debug information.
 876  *
 877  * LTTNG_UST_TRACEPOINT_LOGLEVEL_EMERG           0
 878  * system is unusable
 879  *
 880  * LTTNG_UST_TRACEPOINT_LOGLEVEL_ALERT           1
 881  * action must be taken immediately
 882  *
 883  * LTTNG_UST_TRACEPOINT_LOGLEVEL_CRIT            2
 884  * critical conditions
 885  *
 886  * LTTNG_UST_TRACEPOINT_LOGLEVEL_ERR             3
 887  * error conditions
 888  *
 889  * LTTNG_UST_TRACEPOINT_LOGLEVEL_WARNING         4
 890  * warning conditions
 891  *
 892  * LTTNG_UST_TRACEPOINT_LOGLEVEL_NOTICE          5
 893  * normal, but significant, condition
 894  *
 895  * LTTNG_UST_TRACEPOINT_LOGLEVEL_INFO            6
 896  * informational message
 897  *
 898  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_SYSTEM    7
 899  * debug information with system-level scope (set of programs)
 900  *
 901  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROGRAM   8
 902  * debug information with program-level scope (set of processes)
 903  *
 904  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROCESS   9
 905  * debug information with process-level scope (set of modules)
 906  *
 907  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_MODULE    10
 908  * debug information with module (executable/library) scope (set of units)
 909  *
 910  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_UNIT      11
 911  * debug information with compilation unit scope (set of functions)
 912  *
 913  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_FUNCTION  12
 914  * debug information with function-level scope
 915  *
 916  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_LINE      13
 917  * debug information with line-level scope (LTTNG_UST_TRACEPOINT_EVENT default)
 918  *
 919  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG           14
 920  * debug-level message
 921  *
 922  * Declare tracepoint loglevels for tracepoints. A LTTNG_UST_TRACEPOINT_EVENT
 923  * should be declared prior to the the LTTNG_UST_TRACEPOINT_LOGLEVEL for a given
 924  * tracepoint name. The first field is the provider name, the second
 925  * field is the name of the tracepoint, the third field is the loglevel
 926  * name.
 927  *
 928  *      LTTNG_UST_TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
 929  *              < loglevel_name >)
 930  *
 931  * The LTTNG_UST_TRACEPOINT_PROVIDER must be already declared before declaring a
 932  * LTTNG_UST_TRACEPOINT_LOGLEVEL.
 933  */
 934
 935 enum {
 936         LTTNG_UST_TRACEPOINT_LOGLEVEL_EMERG             = 0,
 937         LTTNG_UST_TRACEPOINT_LOGLEVEL_ALERT             = 1,
 938         LTTNG_UST_TRACEPOINT_LOGLEVEL_CRIT              = 2,
 939         LTTNG_UST_TRACEPOINT_LOGLEVEL_ERR               = 3,
 940         LTTNG_UST_TRACEPOINT_LOGLEVEL_WARNING           = 4,
 941         LTTNG_UST_TRACEPOINT_LOGLEVEL_NOTICE            = 5,
 942         LTTNG_UST_TRACEPOINT_LOGLEVEL_INFO              = 6,
 943         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_SYSTEM      = 7,
 944         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROGRAM     = 8,
 945         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROCESS     = 9,
 946         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_MODULE      = 10,
 947         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_UNIT        = 11,
 948         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_FUNCTION    = 12,
 949         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_LINE        = 13,
 950         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG             = 14,
 951 };
 952
 953 #define LTTNG_UST_TRACEPOINT_LOGLEVEL(provider, name, loglevel)
 954
 955 #if LTTNG_UST_COMPAT_API(0)
 956 #define TRACEPOINT_LOGLEVEL     LTTNG_UST_TRACEPOINT_LOGLEVEL
 957
 958 #define TRACE_EMERG             LTTNG_UST_TRACEPOINT_LOGLEVEL_EMERG
 959 #define TRACE_ALERT             LTTNG_UST_TRACEPOINT_LOGLEVEL_ALERT
 960 #define TRACE_CRIT              LTTNG_UST_TRACEPOINT_LOGLEVEL_CRIT
 961 #define TRACE_ERR               LTTNG_UST_TRACEPOINT_LOGLEVEL_ERR
 962 #define TRACE_WARNING           LTTNG_UST_TRACEPOINT_LOGLEVEL_WARNING
 963 #define TRACE_NOTICE            LTTNG_UST_TRACEPOINT_LOGLEVEL_NOTICE
 964 #define TRACE_INFO              LTTNG_UST_TRACEPOINT_LOGLEVEL_INFO
 965 #define TRACE_DEBUG_SYSTEM      LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_SYSTEM
 966 #define TRACE_DEBUG_PROGRAM     LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROGRAM
 967 #define TRACE_DEBUG_PROCESS     LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROCESS
 968 #define TRACE_DEBUG_MODULE      LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_MODULE
 969 #define TRACE_DEBUG_UNIT        LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_UNIT
 970 #define TRACE_DEBUG_FUNCTION    LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_FUNCTION
 971 #define TRACE_DEBUG_LINE        LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_LINE
 972 #define TRACE_DEBUG             LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG
 973 #endif
 974
 975 #endif /* #ifndef LTTNG_UST_TRACEPOINT_LOGLEVEL */
 976
 977 #ifndef LTTNG_UST_TRACEPOINT_MODEL_EMF_URI
 978
 979 #define LTTNG_UST_TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
 980
 981 #if LTTNG_UST_COMPAT_API(0)
 982 #define TRACEPOINT_MODEL_EMF_URI LTTNG_UST_TRACEPOINT_MODEL_EMF_URI
 983 #endif
 984
 985 #endif /* #ifndef LTTNG_UST_TRACEPOINT_MODEL_EMF_URI */