include/lttng/tracepoint.h

   1 // SPDX-FileCopyrightText: 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   2 //
   3 // SPDX-License-Identifier: MIT
   4
   5 #ifndef _LTTNG_UST_TRACEPOINT_H
   6 #define _LTTNG_UST_TRACEPOINT_H
   7
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <lttng/tracepoint-types.h>
  11 #include <lttng/tracepoint-rcu.h>
  12 #include <lttng/ust-utils.h>
  13 #include <sys/types.h>
  14 #include <unistd.h>
  15
  16 #include <urcu/compiler.h>
  17 #include <urcu/system.h>
  18 #include <dlfcn.h>      /* for dlopen */
  19 #include <string.h>     /* for memset */
  20 #include <stdbool.h>
  21
  22 #include <lttng/ust-config.h>   /* for sdt */
  23 #include <lttng/ust-compiler.h>
  24 #include <lttng/ust-tracer.h>
  25 #include <lttng/ust-api-compat.h>
  26
  27 #if (defined(__cplusplus) && (__cplusplus <= 199711L))
  28 #error "C++11 support is required to build tracepoints and providers as C++"
  29 #endif
  30
  31 #define LTTNG_UST_TRACEPOINT_NAME_LEN_MAX       256
  32
  33 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
  34 /*
  35  * Instead of using SDT_USE_VARIADIC from 'sys/sdt.h', use our own namespaced
  36  * macros since the instrumented application might already have included
  37  * 'sys/sdt.h' without variadic support.
  38  */
  39 #include <sys/sdt.h>
  40
  41 #define LTTNG_UST__SDT_NARG(...) \
  42         LTTNG_UST___SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0)
  43
  44 #define LTTNG_UST___SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N
  45
  46 #define LTTNG_UST__SDT_PROBE_N(provider, name, N, ...) \
  47         _SDT_PROBE(provider, name, N, (__VA_ARGS__))
  48
  49 #define LTTNG_UST_STAP_PROBEV(provider, name, ...) \
  50         LTTNG_UST__SDT_PROBE_N(provider, name, LTTNG_UST__SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__)
  51
  52 #else
  53 #define LTTNG_UST_STAP_PROBEV(...)
  54 #endif
  55
  56 #ifdef __cplusplus
  57 extern "C" {
  58 #endif
  59
  60 #define lttng_ust_tracepoint_enabled(provider, name)                            \
  61         caa_unlikely(CMM_LOAD_SHARED(lttng_ust_tracepoint_##provider##___##name.state))
  62
  63 #define lttng_ust_do_tracepoint(provider, name, ...)                            \
  64         lttng_ust_tracepoint_cb_##provider##___##name(__VA_ARGS__)
  65
  66 #define lttng_ust_tracepoint(provider, name, ...)                               \
  67         do {                                                                    \
  68                 LTTNG_UST_STAP_PROBEV(provider, name, ## __VA_ARGS__);          \
  69                 if (lttng_ust_tracepoint_enabled(provider, name))               \
  70                         lttng_ust_do_tracepoint(provider, name, __VA_ARGS__);   \
  71         } while (0)
  72
  73 #define LTTNG_UST_TP_ARGS(...)       __VA_ARGS__
  74
  75 /*
  76  * LTTNG_UST_TP_ARGS takes tuples of type, argument separated by a comma.
  77  * It can take up to 10 tuples (which means that less than 10 tuples is
  78  * fine too).
  79  * Each tuple is also separated by a comma.
  80  */
  81 #define LTTNG_UST___TP_COMBINE_TOKENS(_tokena, _tokenb)                         \
  82                 _tokena##_tokenb
  83 #define LTTNG_UST__TP_COMBINE_TOKENS(_tokena, _tokenb)                          \
  84                 LTTNG_UST___TP_COMBINE_TOKENS(_tokena, _tokenb)
  85 #define LTTNG_UST___TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)                       \
  86                 _tokena##_tokenb##_tokenc
  87 #define LTTNG_UST__TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)                        \
  88                 LTTNG_UST___TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
  89 #define LTTNG_UST___TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)      \
  90                 _tokena##_tokenb##_tokenc##_tokend
  91 #define LTTNG_UST__TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)               \
  92                 LTTNG_UST___TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
  93
  94 /*
  95  * LTTNG_UST__TP_EXVAR* extract the var names.
  96  * LTTNG_UST__TP_EXVAR1 and LTTNG_UST__TP_EXDATA_VAR1 are needed for -std=c99.
  97  */
  98 #define LTTNG_UST__TP_EXVAR0()
  99 #define LTTNG_UST__TP_EXVAR1(a)
 100 #define LTTNG_UST__TP_EXVAR2(a,b)                                               b
 101 #define LTTNG_UST__TP_EXVAR4(a,b,c,d)                                   b,d
 102 #define LTTNG_UST__TP_EXVAR6(a,b,c,d,e,f)                                       b,d,f
 103 #define LTTNG_UST__TP_EXVAR8(a,b,c,d,e,f,g,h)                           b,d,f,h
 104 #define LTTNG_UST__TP_EXVAR10(a,b,c,d,e,f,g,h,i,j)                      b,d,f,h,j
 105 #define LTTNG_UST__TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l)                  b,d,f,h,j,l
 106 #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
 107 #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
 108 #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
 109 #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
 110
 111 #define LTTNG_UST__TP_EXDATA_VAR0()                                             __tp_data
 112 #define LTTNG_UST__TP_EXDATA_VAR1(a)                                            __tp_data
 113 #define LTTNG_UST__TP_EXDATA_VAR2(a,b)                                          __tp_data,b
 114 #define LTTNG_UST__TP_EXDATA_VAR4(a,b,c,d)                                      __tp_data,b,d
 115 #define LTTNG_UST__TP_EXDATA_VAR6(a,b,c,d,e,f)                                  __tp_data,b,d,f
 116 #define LTTNG_UST__TP_EXDATA_VAR8(a,b,c,d,e,f,g,h)                              __tp_data,b,d,f,h
 117 #define LTTNG_UST__TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j)                         __tp_data,b,d,f,h,j
 118 #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
 119 #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
 120 #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
 121 #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
 122 #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
 123
 124 /*
 125  * LTTNG_UST__TP_EXPROTO* extract tuples of type, var.
 126  * LTTNG_UST__TP_EXPROTO1 and LTTNG_UST__TP_EXDATA_PROTO1 are needed for -std=c99.
 127  */
 128 #define LTTNG_UST__TP_EXPROTO0()                                                void
 129 #define LTTNG_UST__TP_EXPROTO1(a)                                               void
 130 #define LTTNG_UST__TP_EXPROTO2(a,b)                                     a b
 131 #define LTTNG_UST__TP_EXPROTO4(a,b,c,d)                                 a b,c d
 132 #define LTTNG_UST__TP_EXPROTO6(a,b,c,d,e,f)                             a b,c d,e f
 133 #define LTTNG_UST__TP_EXPROTO8(a,b,c,d,e,f,g,h)                         a b,c d,e f,g h
 134 #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
 135 #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
 136 #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
 137 #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
 138 #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
 139 #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
 140
 141 #define LTTNG_UST__TP_EXDATA_PROTO0()                                           void *__tp_data
 142 #define LTTNG_UST__TP_EXDATA_PROTO1(a)                                          void *__tp_data
 143 #define LTTNG_UST__TP_EXDATA_PROTO2(a,b)                                                void *__tp_data,a b
 144 #define LTTNG_UST__TP_EXDATA_PROTO4(a,b,c,d)                                    void *__tp_data,a b,c d
 145 #define LTTNG_UST__TP_EXDATA_PROTO6(a,b,c,d,e,f)                                        void *__tp_data,a b,c d,e f
 146 #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
 147 #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
 148 #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
 149 #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
 150 #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
 151 #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
 152 #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
 153
 154 /* Preprocessor trick to count arguments. Inspired from sdt.h. */
 155 #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)
 156 #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
 157 #define LTTNG_UST__TP_PROTO_N(N, ...)           LTTNG_UST__TP_PARAMS(LTTNG_UST__TP_COMBINE_TOKENS(LTTNG_UST__TP_EXPROTO, N)(__VA_ARGS__))
 158 #define LTTNG_UST__TP_VAR_N(N, ...)             LTTNG_UST__TP_PARAMS(LTTNG_UST__TP_COMBINE_TOKENS(LTTNG_UST__TP_EXVAR, N)(__VA_ARGS__))
 159 #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__))
 160 #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__))
 161 #define LTTNG_UST__TP_ARGS_PROTO(...)           LTTNG_UST__TP_PROTO_N(LTTNG_UST__TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 162 #define LTTNG_UST__TP_ARGS_VAR(...)             LTTNG_UST__TP_VAR_N(LTTNG_UST__TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 163 #define LTTNG_UST__TP_ARGS_DATA_PROTO(...)      LTTNG_UST__TP_DATA_PROTO_N(LTTNG_UST__TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 164 #define LTTNG_UST__TP_ARGS_DATA_VAR(...)        LTTNG_UST__TP_DATA_VAR_N(LTTNG_UST__TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 165 #define LTTNG_UST__TP_PARAMS(...)               __VA_ARGS__
 166
 167 /*
 168  * sizeof(#_provider) - 1 : length of the provider string (excluding \0).
 169  * sizeof(#_name) - 1     : length of the name string (excluding \0).
 170  * + 1                    : separator between provider and event name.
 171  *
 172  * Upper bound (inclusive) is LTTNG_UST_TRACEPOINT_NAME_LEN_MAX - 1 to
 173  * account for \0.
 174  *
 175  * The comparison is:
 176  *   left hand side:   sizeof(#_provider) - 1 + sizeof(#_name) - 1 + 1
 177  *   right hand side:  LTTNG_UST_TRACEPOINT_NAME_LEN_MAX - 1
 178  *   operator:         <=  (inclusive)
 179  * Simplified in the code below.
 180  */
 181 #define lttng_ust_tracepoint_validate_name_len(_provider, _name)                                                \
 182         lttng_ust_static_assert(sizeof(#_provider) + sizeof(#_name) <= LTTNG_UST_TRACEPOINT_NAME_LEN_MAX,       \
 183                 "Tracepoint name length is too long",                                                           \
 184                 Tracepoint_name_length_is_too_long)
 185
 186 /*
 187  * The tracepoint cb is marked always inline so we can distinguish
 188  * between caller's ip addresses within the probe using the return
 189  * address.
 190  */
 191 #define LTTNG_UST__DECLARE_TRACEPOINT(_provider, _name, ...)                                    \
 192 extern struct lttng_ust_tracepoint lttng_ust_tracepoint_##_provider##___##_name         \
 193                 LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY;                            \
 194 static inline                                                                           \
 195 void lttng_ust_tracepoint_cb_##_provider##___##_name(LTTNG_UST__TP_ARGS_PROTO(__VA_ARGS__))             \
 196         __attribute__((always_inline, unused)) lttng_ust_notrace;                       \
 197 static                                                                                  \
 198 void lttng_ust_tracepoint_cb_##_provider##___##_name(LTTNG_UST__TP_ARGS_PROTO(__VA_ARGS__))             \
 199 {                                                                                       \
 200         struct lttng_ust_tracepoint_probe *__tp_probe;                                  \
 201                                                                                         \
 202         if (caa_unlikely(!LTTNG_UST_TP_RCU_LINK_TEST()))                                                \
 203                 return;                                                                 \
 204         lttng_ust_tp_rcu_read_lock();                                                           \
 205         __tp_probe = lttng_ust_tp_rcu_dereference(lttng_ust_tracepoint_##_provider##___##_name.probes); \
 206         if (caa_unlikely(!__tp_probe))                                                  \
 207                 goto end;                                                               \
 208         do {                                                                            \
 209                 void (*__tp_cb)(void) = __tp_probe->func;                               \
 210                 void *__tp_data = __tp_probe->data;                                     \
 211                                                                                         \
 212                 URCU_FORCE_CAST(void (*)(LTTNG_UST__TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb)  \
 213                                 (LTTNG_UST__TP_ARGS_DATA_VAR(__VA_ARGS__));                     \
 214         } while ((++__tp_probe)->func);                                                 \
 215 end:                                                                                    \
 216         lttng_ust_tp_rcu_read_unlock();                                                         \
 217 }                                                                                       \
 218 static inline                                                                           \
 219 void lttng_ust_tracepoint_register_##_provider##___##_name(char *provider_name, char *event_name, \
 220                 void (*func)(void), void *data)                                         \
 221         lttng_ust_notrace;                                                              \
 222 static inline                                                                           \
 223 void lttng_ust_tracepoint_register_##_provider##___##_name(char *provider_name, char *event_name, \
 224                 void (*func)(void), void *data)                                         \
 225 {                                                                                       \
 226         lttng_ust_tracepoint_provider_register(provider_name, event_name, func, data,           \
 227                 lttng_ust_tracepoint_##_provider##___##_name.signature);                        \
 228 }                                                                                       \
 229 static inline                                                                           \
 230 void lttng_ust_tracepoint_unregister_##_provider##___##_name(char *provider_name, char *event_name, \
 231                 void (*func)(void), void *data)                                         \
 232         lttng_ust_notrace;                                                              \
 233 static inline                                                                           \
 234 void lttng_ust_tracepoint_unregister_##_provider##___##_name(char *provider_name, char *event_name, \
 235                 void (*func)(void), void *data)                                         \
 236 {                                                                                       \
 237         lttng_ust_tracepoint_provider_unregister(provider_name, event_name, func, data);                \
 238 }
 239
 240 /*
 241  * Registration of tracepoint provider probe functions with
 242  * lttng_ust_tracepoint_provider_register, unregistration with
 243  * lttng_ust_tracepoint_provider_unregister.
 244  */
 245 int lttng_ust_tracepoint_provider_register(const char *provider_name, const char *event_name,
 246                 void (*func)(void), void *data, const char *signature);
 247 int lttng_ust_tracepoint_provider_unregister(const char *provider_name, const char *event_name,
 248                 void (*func)(void), void *data);
 249
 250 /*
 251  * Registration of tracepoint instrumentation modules with lttng_ust_tracepoint_module_register,
 252  * unregistration with lttng_ust_tracepoint_module_unregister.
 253  */
 254 int lttng_ust_tracepoint_module_register(struct lttng_ust_tracepoint * const *tracepoints_start,
 255                              int tracepoints_count);
 256 int lttng_ust_tracepoint_module_unregister(struct lttng_ust_tracepoint * const *tracepoints_start);
 257
 258 /*
 259  * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
 260  * shared across objects in a module/main executable.
 261  *
 262  * IMPORTANT: this structure is part of the ABI between instrumented
 263  * applications and UST. Fields need to be only added at the end, never
 264  * reordered, never removed.
 265  *
 266  * The field @struct_size should be used to determine the size of the
 267  * structure. It should be queried before using additional fields added
 268  * at the end of the structure.
 269  */
 270 struct lttng_ust_tracepoint_dlopen {
 271         uint32_t struct_size;
 272
 273         void *liblttngust_handle;
 274
 275         int (*lttng_ust_tracepoint_module_register)(struct lttng_ust_tracepoint * const *tracepoints_start,
 276                 int tracepoints_count);
 277         int (*lttng_ust_tracepoint_module_unregister)(struct lttng_ust_tracepoint * const *tracepoints_start);
 278         void (*rcu_read_lock_sym)(void);
 279         void (*rcu_read_unlock_sym)(void);
 280         void *(*rcu_dereference_sym)(void *p);
 281
 282         /* End of base ABI. Fields below should be used after checking struct_size. */
 283 };
 284
 285 extern struct lttng_ust_tracepoint_dlopen lttng_ust_tracepoint_dlopen;
 286 extern struct lttng_ust_tracepoint_dlopen *lttng_ust_tracepoint_dlopen_ptr;
 287
 288 /*
 289  * These weak symbols, the constructor, and destructor take care of
 290  * registering only _one_ instance of the tracepoints per shared-ojbect
 291  * (or for the whole main program).
 292  */
 293 int lttng_ust_tracepoint_registered
 294         __attribute__((weak, visibility("hidden")));
 295 int lttng_ust_tracepoint_ptrs_registered
 296         __attribute__((weak, visibility("hidden")));
 297 struct lttng_ust_tracepoint_dlopen lttng_ust_tracepoint_dlopen
 298                 __attribute__((weak, visibility("hidden"))) = {
 299         .struct_size = sizeof(struct lttng_ust_tracepoint_dlopen),
 300 };
 301 /*
 302  * Deal with gcc O1 optimisation issues with weak hidden symbols. gcc
 303  * 4.8 and prior does not have the same behavior for symbol scoping on
 304  * 32-bit powerpc depending on the object size: symbols for objects of 8
 305  * bytes or less have the same address throughout a module, whereas they
 306  * have different addresses between compile units for objects larger
 307  * than 8 bytes. Add this pointer indirection to ensure that the symbol
 308  * scoping match that of the other weak hidden symbols found in this
 309  * header.
 310  */
 311 struct lttng_ust_tracepoint_dlopen *lttng_ust_tracepoint_dlopen_ptr
 312         __attribute__((weak, visibility("hidden")));
 313
 314 /*
 315  * Tracepoint dynamic linkage handling (callbacks). Hidden visibility: shared
 316  * across objects in a module/main executable. The callbacks are used to
 317  * control and check if the destructors should be executed.
 318  *
 319  * IMPORTANT: this structure is part of the ABI between instrumented
 320  * applications and UST. Fields need to be only added at the end, never
 321  * reordered, never removed.
 322  *
 323  * The field @struct_size should be used to determine the size of the
 324  * structure. It should be queried before using additional fields added
 325  * at the end of the structure.
 326  */
 327 struct lttng_ust_tracepoint_destructors_syms {
 328         uint32_t struct_size;
 329
 330         void (*tracepoint_disable_destructors)(void);
 331         int (*tracepoint_get_destructors_state)(void);
 332
 333         /* End of base ABI. Fields below should be used after checking struct_size. */
 334 };
 335
 336 extern struct lttng_ust_tracepoint_destructors_syms lttng_ust_tracepoint_destructors_syms;
 337 extern struct lttng_ust_tracepoint_destructors_syms *lttng_ust_tracepoint_destructors_syms_ptr;
 338
 339 struct lttng_ust_tracepoint_destructors_syms lttng_ust_tracepoint_destructors_syms
 340         __attribute__((weak, visibility("hidden"))) = {
 341         .struct_size = sizeof(struct lttng_ust_tracepoint_destructors_syms),
 342 };
 343 struct lttng_ust_tracepoint_destructors_syms *lttng_ust_tracepoint_destructors_syms_ptr
 344         __attribute__((weak, visibility("hidden")));
 345
 346 static inline void tracepoint_disable_destructors(void)
 347 {
 348         if (!lttng_ust_tracepoint_dlopen_ptr)
 349                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 350         if (!lttng_ust_tracepoint_destructors_syms_ptr)
 351                 lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 352         if (lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle
 353                         && lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_disable_destructors)
 354                 lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_disable_destructors();
 355 }
 356
 357 #ifndef _LGPL_SOURCE
 358 static inline void
 359 lttng_ust_tracepoint__init_urcu_sym(void)
 360         lttng_ust_notrace;
 361 static inline void
 362 lttng_ust_tracepoint__init_urcu_sym(void)
 363 {
 364         if (!lttng_ust_tracepoint_dlopen_ptr)
 365                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 366         /*
 367          * Symbols below are needed by tracepoint call sites and probe
 368          * providers.
 369          */
 370         if (!lttng_ust_tracepoint_dlopen_ptr->rcu_read_lock_sym)
 371                 lttng_ust_tracepoint_dlopen_ptr->rcu_read_lock_sym =
 372                         URCU_FORCE_CAST(void (*)(void),
 373                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 374                                         "lttng_ust_tp_rcu_read_lock"));
 375         if (!lttng_ust_tracepoint_dlopen_ptr->rcu_read_unlock_sym)
 376                 lttng_ust_tracepoint_dlopen_ptr->rcu_read_unlock_sym =
 377                         URCU_FORCE_CAST(void (*)(void),
 378                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 379                                         "lttng_ust_tp_rcu_read_unlock"));
 380         if (!lttng_ust_tracepoint_dlopen_ptr->rcu_dereference_sym)
 381                 lttng_ust_tracepoint_dlopen_ptr->rcu_dereference_sym =
 382                         URCU_FORCE_CAST(void *(*)(void *p),
 383                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 384                                         "lttng_ust_tp_rcu_dereference_sym"));
 385 }
 386 #else
 387 static inline void
 388 lttng_ust_tracepoint__init_urcu_sym(void)
 389         lttng_ust_notrace;
 390 static inline void
 391 lttng_ust_tracepoint__init_urcu_sym(void)
 392 {
 393 }
 394 #endif
 395
 396 /*
 397  * Use getenv() directly and bypass lttng-ust helper functions
 398  * because we may not have access to lttng-ust shared libraries.
 399  */
 400 #ifdef LTTNG_UST_DEBUG
 401 static inline
 402 bool lttng_ust_tracepoint_logging_debug_enabled(void)
 403 {
 404         return true;
 405 }
 406 #else /* #ifdef LTTNG_UST_DEBUG */
 407 static inline
 408 bool lttng_ust_tracepoint_logging_debug_enabled(void)
 409 {
 410         return getenv("LTTNG_UST_DEBUG");
 411 }
 412 #endif /* #ifdef LTTNG_UST_DEBUG */
 413
 414 #ifdef LTTNG_UST_ABORT_ON_CRITICAL
 415 static inline
 416 bool lttng_ust_tracepoint_logging_abort_on_critical_enabled(void)
 417 {
 418         return true;
 419 }
 420 #else /* #ifdef LTTNG_UST_ABORT_ON_CRITICAL */
 421 static inline
 422 bool lttng_ust_tracepoint_logging_abort_on_critical_enabled(void)
 423 {
 424         return getenv("LTTNG_UST_ABORT_ON_CRITICAL");
 425 }
 426 #endif
 427
 428 #define LTTNG_UST_TRACEPOINT_THIS_IP            \
 429         ({ __label__ here; here: &&here; })
 430
 431 static void
 432 lttng_ust_tracepoints_print_disabled_message(void)
 433 {
 434         if (lttng_ust_tracepoint_logging_debug_enabled())
 435                 fprintf(stderr, "lttng-ust-tracepoint [%ld]: Critical: dlopen() failed to find '%s', tracepoints in this binary won't be registered. "
 436                         "(at addr=%p in %s() at " __FILE__ ":" lttng_ust_stringify(__LINE__) ")\n",
 437                         (long) getpid(),
 438                         LTTNG_UST_TRACEPOINT_LIB_SONAME,
 439                         LTTNG_UST_TRACEPOINT_THIS_IP,
 440                         __func__);
 441         if (lttng_ust_tracepoint_logging_abort_on_critical_enabled())
 442                 abort();
 443 }
 444
 445 static void
 446 lttng_ust__tracepoints__init(void)
 447         lttng_ust_notrace __attribute__((constructor(LTTNG_UST_CONSTRUCTOR_PRIO)));
 448 static void
 449 lttng_ust__tracepoints__init(void)
 450 {
 451         if (lttng_ust_tracepoint_registered++) {
 452                 if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 453                         return;
 454                 lttng_ust_tracepoint__init_urcu_sym();
 455                 return;
 456         }
 457
 458         if (!lttng_ust_tracepoint_dlopen_ptr)
 459                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 460         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 461                 lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle =
 462                         dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
 463         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle) {
 464                 lttng_ust_tracepoints_print_disabled_message();
 465                 return;
 466         }
 467         lttng_ust_tracepoint__init_urcu_sym();
 468 }
 469
 470 static void
 471 lttng_ust__tracepoints__destroy(void)
 472         lttng_ust_notrace __attribute__((destructor(LTTNG_UST_CONSTRUCTOR_PRIO)));
 473 static void
 474 lttng_ust__tracepoints__destroy(void)
 475 {
 476         int ret;
 477
 478         if (--lttng_ust_tracepoint_registered)
 479                 return;
 480         if (!lttng_ust_tracepoint_dlopen_ptr)
 481                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 482         if (!lttng_ust_tracepoint_destructors_syms_ptr)
 483                 lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 484         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 485                 return;
 486         if (lttng_ust_tracepoint_ptrs_registered)
 487                 return;
 488         /*
 489          * Lookup if destructors must be executed using the new method.
 490          */
 491         if (lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
 492                 && !lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()) {
 493                 /*
 494                  * The tracepoint_get_destructors_state symbol was found with
 495                  * dlsym but its returned value is 0 meaning that destructors
 496                  * must not be executed.
 497                  */
 498                 return;
 499         }
 500         ret = dlclose(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle);
 501         if (ret) {
 502                 fprintf(stderr, "Error (%d) in dlclose\n", ret);
 503                 abort();
 504         }
 505         memset(lttng_ust_tracepoint_dlopen_ptr, 0, sizeof(*lttng_ust_tracepoint_dlopen_ptr));
 506 }
 507
 508 #if LTTNG_UST_COMPAT_API(0)
 509 # if defined(TRACEPOINT_DEFINE) && !defined(LTTNG_UST_TRACEPOINT_DEFINE)
 510 #  define LTTNG_UST_TRACEPOINT_DEFINE
 511 # endif
 512 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 513
 514 #if LTTNG_UST_COMPAT_API(0)
 515 #define tracepoint                      lttng_ust_tracepoint
 516 #define do_tracepoint                   lttng_ust_do_tracepoint
 517 #define tracepoint_enabled              lttng_ust_tracepoint_enabled
 518 #define TP_ARGS                         LTTNG_UST_TP_ARGS
 519 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 520
 521 #ifdef __cplusplus
 522 }
 523 #endif
 524
 525 #endif /* _LTTNG_UST_TRACEPOINT_H */
 526
 527 /* The following declarations must be outside re-inclusion protection. */
 528
 529 #ifdef LTTNG_UST_TRACEPOINT_DEFINE
 530
 531 #ifndef _LTTNG_UST_TRACEPOINT_DEFINE_ONCE
 532 #define _LTTNG_UST_TRACEPOINT_DEFINE_ONCE
 533
 534 #ifdef __cplusplus
 535 extern "C" {
 536 #endif
 537
 538 /*
 539  * These weak symbols, the constructor, and destructor take care of
 540  * registering only _one_ instance of the tracepoints per shared-ojbect
 541  * (or for the whole main program).
 542  */
 543 extern struct lttng_ust_tracepoint * const __start_lttng_ust_tracepoints_ptrs[]
 544         __attribute__((weak, visibility("hidden")));
 545 extern struct lttng_ust_tracepoint * const __stop_lttng_ust_tracepoints_ptrs[]
 546         __attribute__((weak, visibility("hidden")));
 547
 548 /*
 549  * When LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
 550  * unresolved symbol that requires the provider to be linked in. When
 551  * LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
 552  * unresolved symbol that depends on having the provider linked in,
 553  * otherwise the linker complains. This deals with use of static
 554  * libraries, ensuring that the linker does not remove the provider
 555  * object from the executable.
 556  */
 557
 558 #if LTTNG_UST_COMPAT_API(0)
 559 # if defined(TRACEPOINT_PROBE_DYNAMIC_LINKAGE) && !defined(LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE)
 560 #  define LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE
 561 # endif
 562 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 563
 564 #ifdef LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE
 565 #define LTTNG_UST__TRACEPOINT_UNDEFINED_REF(provider)   NULL
 566 #else   /* LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
 567 #define LTTNG_UST__TRACEPOINT_UNDEFINED_REF(provider)   &lttng_ust_tracepoint_provider_##provider
 568 #endif /* LTTNG_UST_TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
 569
 570 /*
 571  * Note: to allow PIC code, we need to allow the linker to update the pointers
 572  * in the lttng_ust_tracepoints_ptrs section.
 573  * Therefore, this section is _not_ const (read-only).
 574  */
 575 #define LTTNG_UST__TP_EXTRACT_STRING(...)       #__VA_ARGS__
 576
 577 #undef LTTNG_UST__DEFINE_TRACEPOINT
 578 #define LTTNG_UST__DEFINE_TRACEPOINT(_provider, _name, _args)                           \
 579         lttng_ust_tracepoint_validate_name_len(_provider, _name);               \
 580         extern int lttng_ust_tracepoint_provider_##_provider                    \
 581                 LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY;           \
 582         static const char lttng_ust_tp_provider_strtab_##_provider##___##_name[]        \
 583                 __attribute__((section("lttng_ust_tracepoints_strings"))) =             \
 584                         #_provider;                                             \
 585         static const char lttng_ust_tp_name_strtab_##_provider##___##_name[]            \
 586                 __attribute__((section("lttng_ust_tracepoints_strings"))) =             \
 587                         #_name;                                                 \
 588         struct lttng_ust_tracepoint lttng_ust_tracepoint_##_provider##___##_name        \
 589                 __attribute__((section("lttng_ust_tracepoints")))               \
 590                 LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY = {                 \
 591                         sizeof(struct lttng_ust_tracepoint),                    \
 592                         lttng_ust_tp_provider_strtab_##_provider##___##_name,           \
 593                         lttng_ust_tp_name_strtab_##_provider##___##_name,               \
 594                         0,                                                      \
 595                         NULL,                                                   \
 596                         LTTNG_UST__TRACEPOINT_UNDEFINED_REF(_provider),         \
 597                         LTTNG_UST__TP_EXTRACT_STRING(_args),                    \
 598                 };                                                              \
 599         static struct lttng_ust_tracepoint *                                    \
 600                 lttng_ust_tracepoint_ptr_##_provider##___##_name                        \
 601                 __attribute__((section("lttng_ust_tracepoints_ptrs"), used))            \
 602                 __lttng_ust_variable_attribute_no_sanitize_address =            \
 603                         &lttng_ust_tracepoint_##_provider##___##_name;
 604
 605 static void
 606 lttng_ust__tracepoints__ptrs_init(void)
 607         lttng_ust_notrace __attribute__((constructor(LTTNG_UST_CONSTRUCTOR_PRIO)));
 608 static void
 609 lttng_ust__tracepoints__ptrs_init(void)
 610 {
 611         if (lttng_ust_tracepoint_ptrs_registered++)
 612                 return;
 613         if (!lttng_ust_tracepoint_dlopen_ptr)
 614                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 615         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 616                 lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle =
 617                         dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
 618         if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle) {
 619                 lttng_ust_tracepoints_print_disabled_message();
 620                 return;
 621         }
 622         if (!lttng_ust_tracepoint_destructors_syms_ptr)
 623                 lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 624         lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_register =
 625                 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int),
 626                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 627                                         "lttng_ust_tracepoint_module_register"));
 628         lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_unregister =
 629                 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *),
 630                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 631                                         "lttng_ust_tracepoint_module_unregister"));
 632         lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_disable_destructors =
 633                 URCU_FORCE_CAST(void (*)(void),
 634                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 635                                         "lttng_ust_tp_disable_destructors"));
 636         lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state =
 637                 URCU_FORCE_CAST(int (*)(void),
 638                                 dlsym(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle,
 639                                         "lttng_ust_tp_get_destructors_state"));
 640         lttng_ust_tracepoint__init_urcu_sym();
 641         if (lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_register) {
 642                 lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_register(__start_lttng_ust_tracepoints_ptrs,
 643                                 __stop_lttng_ust_tracepoints_ptrs -
 644                                 __start_lttng_ust_tracepoints_ptrs);
 645         }
 646 }
 647
 648 static void
 649 lttng_ust__tracepoints__ptrs_destroy(void)
 650         lttng_ust_notrace __attribute__((destructor(LTTNG_UST_CONSTRUCTOR_PRIO)));
 651 static void
 652 lttng_ust__tracepoints__ptrs_destroy(void)
 653 {
 654         int ret;
 655
 656         if (--lttng_ust_tracepoint_ptrs_registered)
 657                 return;
 658         if (!lttng_ust_tracepoint_dlopen_ptr)
 659                 lttng_ust_tracepoint_dlopen_ptr = &lttng_ust_tracepoint_dlopen;
 660         if (!lttng_ust_tracepoint_destructors_syms_ptr)
 661                 lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 662         if (lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_unregister)
 663                 lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_unregister(__start_lttng_ust_tracepoints_ptrs);
 664         if (lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle
 665                         && lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
 666                         && lttng_ust_tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()
 667                         && !lttng_ust_tracepoint_ptrs_registered) {
 668                 ret = dlclose(lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle);
 669                 if (ret) {
 670                         fprintf(stderr, "Error (%d) in dlclose\n", ret);
 671                         abort();
 672                 }
 673                 memset(lttng_ust_tracepoint_dlopen_ptr, 0, sizeof(*lttng_ust_tracepoint_dlopen_ptr));
 674         }
 675 }
 676
 677 #ifdef __cplusplus
 678 }
 679 #endif
 680
 681 #endif /* _LTTNG_UST_TRACEPOINT_DEFINE_ONCE */
 682
 683 #else /* LTTNG_UST_TRACEPOINT_DEFINE */
 684
 685 #undef LTTNG_UST__DEFINE_TRACEPOINT
 686 #define LTTNG_UST__DEFINE_TRACEPOINT(_provider, _name, _args)
 687
 688 #endif /* #else LTTNG_UST_TRACEPOINT_DEFINE */
 689
 690 /*
 691  * LTTNG_UST_TRACEPOINT_HIDDEN_DEFINITION: Define this before including
 692  * a tracepoint instrumentation header to hide symbols associated with
 693  * tracepoint module instrumentation. This is useful if all compile
 694  * units using the lttng_ust_tracepoint(),
 695  * lttng_ust_tracepoint_enabled() and lttng_ust_do_tracepoint() macros
 696  * is within the same module as the compile unit including the
 697  * tracepoint header after defining LTTNG_UST_TRACEPOINT_DEFINE.
 698  */
 699
 700 #undef LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY
 701 #ifdef LTTNG_UST_TRACEPOINT_HIDDEN_DEFINITION
 702 #define LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY             __attribute__((visibility("hidden")))
 703 #else
 704 #define LTTNG_UST__TRACEPOINT_DEFINITION_VISIBILITY             __attribute__((visibility("default")))
 705 #endif
 706
 707 /*
 708  * LTTNG_UST_TRACEPOINT_PROVIDER_HIDDEN_DEFINITION: Define this before
 709  * including a tracepoint instrumentation header to hide symbols
 710  * associated with the tracepoint provider. This is useful if the
 711  * tracepoint definition (including the header after defining
 712  * LTTNG_UST_TRACEPOINT_DEFINE) is in the same module as the provider
 713  * (including the header after defining
 714  * LTTNG_UST_TRACEPOINT_CREATE_PROBES).
 715  */
 716 #undef LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY
 717 #ifdef LTTNG_UST_TRACEPOINT_PROVIDER_HIDDEN_DEFINITION
 718 #define LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY    __attribute__((visibility("hidden")))
 719 #else
 720 #define LTTNG_UST__TRACEPOINT_PROVIDER_DEFINITION_VISIBILITY    __attribute__((visibility("default")))
 721 #endif
 722
 723 #ifndef LTTNG_UST_TRACEPOINT_ENUM
 724
 725 /*
 726  * Tracepoint Enumerations
 727  *
 728  * The enumeration is a mapping between an integer, or range of integers, and
 729  * a string. It can be used to have a more compact trace in cases where the
 730  * possible values for a field are limited:
 731  *
 732  * An example:
 733  *
 734  * LTTNG_UST_TRACEPOINT_ENUM(someproject_component, enumname,
 735  *      LTTNG_UST_TP_ENUM_VALUES(
 736  *              lttng_ust_field_enum_value("even", 0)
 737  *              lttng_ust_field_enum_value("uneven", 1)
 738  *              lttng_ust_field_enum_range("twoto4", 2, 4)
 739  *              lttng_ust_field_enum_value("five", 5)
 740  *      )
 741  * )
 742  *
 743  * Where "someproject_component" is the name of the component this enumeration
 744  * belongs to and "enumname" identifies this enumeration. Inside the
 745  * LTTNG_UST_TP_ENUM_VALUES macro is the actual mapping. Each string value can map
 746  * to either a single value with lttng_ust_field_enum_value or a range of values
 747  * with lttng_ust_field_enum_range.
 748  *
 749  * Enumeration ranges may overlap, but the behavior is implementation-defined,
 750  * each trace reader will handle overlapping as it wishes.
 751  *
 752  * That enumeration can then be used in a field inside the TP_FIELD macro using
 753  * the following line:
 754  *
 755  * lttng_ust_field_enum(someproject_component, enumname, enumtype, enumfield, enumval)
 756  *
 757  * Where "someproject_component" and "enumname" match those in the
 758  * LTTNG_UST_TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
 759  * backing the enumeration, "enumfield" is the name of the field and
 760  * "enumval" is the value.
 761  */
 762
 763 #define LTTNG_UST_TRACEPOINT_ENUM(provider, name, values)
 764
 765 #if LTTNG_UST_COMPAT_API(0)
 766 #define TRACEPOINT_ENUM         LTTNG_UST_TRACEPOINT_ENUM
 767 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 768
 769 #endif /* #ifndef LTTNG_UST_TRACEPOINT_ENUM */
 770
 771 #ifndef LTTNG_UST_TRACEPOINT_EVENT
 772
 773 /*
 774  * How to use the LTTNG_UST_TRACEPOINT_EVENT macro:
 775  *
 776  * An example:
 777  *
 778  * LTTNG_UST_TRACEPOINT_EVENT(someproject_component, event_name,
 779  *
 780  *     * LTTNG_UST_TP_ARGS takes from 0 to 10 "type, field_name" pairs *
 781  *
 782  *     LTTNG_UST_TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
 783  *             long *, arg4, size_t, arg4_len),
 784  *
 785  *      * LTTNG_UST_TP_FIELDS describes the event payload layout in the trace *
 786  *
 787  *     LTTNG_UST_TP_FIELDS(
 788  *         * Integer, printed in base 10 *
 789  *         lttng_ust_field_integer(int, field_a, arg0)
 790  *
 791  *         * Integer, printed with 0x base 16 *
 792  *         lttng_ust_field_integer_hex(unsigned long, field_d, arg1)
 793  *
 794  *         * Enumeration *
 795  *         lttng_ust_field_enum(someproject_component, enum_name, int, field_e, arg0)
 796  *
 797  *         * Array Sequence, printed as UTF8-encoded array of bytes *
 798  *         lttng_ust_field_array_text(char, field_b, string, FIXED_LEN)
 799  *         lttng_ust_field_sequence_text(char, field_c, string, size_t, strlen)
 800  *
 801  *         * String, printed as UTF8-encoded string *
 802  *         lttng_ust_field_string(field_e, string)
 803  *
 804  *         * Array sequence of signed integer values *
 805  *         lttng_ust_field_array(long, field_f, arg4, FIXED_LEN4)
 806  *         lttng_ust_field_sequence(long, field_g, arg4, size_t, arg4_len)
 807  *     )
 808  * )
 809  *
 810  * More detailed explanation:
 811  *
 812  * The name of the tracepoint is expressed as a tuple with the provider
 813  * and name arguments.
 814  *
 815  * The provider and name should be a proper C99 identifier.
 816  * The "provider" and "name" MUST follow these rules to ensure no
 817  * namespace clash occurs:
 818  *
 819  * For projects (applications and libraries) for which an entity
 820  * specific to the project controls the source code and thus its
 821  * tracepoints (typically with a scope larger than a single company):
 822  *
 823  * either:
 824  *   project_component, event
 825  * or:
 826  *   project, event
 827  *
 828  * Where "project" is the name of the project,
 829  *       "component" is the name of the project component (which may
 830  *       include several levels of sub-components, e.g.
 831  *       ...component_subcomponent_...) where the tracepoint is located
 832  *       (optional),
 833  *       "event" is the name of the tracepoint event.
 834  *
 835  * For projects issued from a single company wishing to advertise that
 836  * the company controls the source code and thus the tracepoints, the
 837  * "com_" prefix should be used:
 838  *
 839  * either:
 840  *   com_company_project_component, event
 841  * or:
 842  *   com_company_project, event
 843  *
 844  * Where "company" is the name of the company,
 845  *       "project" is the name of the project,
 846  *       "component" is the name of the project component (which may
 847  *       include several levels of sub-components, e.g.
 848  *       ...component_subcomponent_...) where the tracepoint is located
 849  *       (optional),
 850  *       "event" is the name of the tracepoint event.
 851  *
 852  * the provider:event identifier is limited to 127 characters.
 853  */
 854
 855 #define LTTNG_UST_TRACEPOINT_EVENT(provider, name, args, fields)                        \
 856         LTTNG_UST__DECLARE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))               \
 857         LTTNG_UST__DEFINE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))
 858
 859 #define LTTNG_UST_TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
 860
 861 #define LTTNG_UST_TRACEPOINT_EVENT_INSTANCE(template_provider, template_name, provider, name, args)     \
 862         LTTNG_UST__DECLARE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))               \
 863         LTTNG_UST__DEFINE_TRACEPOINT(provider, name, LTTNG_UST__TP_PARAMS(args))
 864
 865 #if LTTNG_UST_COMPAT_API(0)
 866 #define TRACEPOINT_EVENT                LTTNG_UST_TRACEPOINT_EVENT
 867 #define TRACEPOINT_EVENT_CLASS          LTTNG_UST_TRACEPOINT_EVENT_CLASS
 868 #define TRACEPOINT_EVENT_INSTANCE(_provider, _template, _name, args)    \
 869         LTTNG_UST_TRACEPOINT_EVENT_INSTANCE(_provider, _template,       \
 870                 _provider, _name, LTTNG_UST__TP_PARAMS(args))
 871
 872 #endif /* #if LTTNG_UST_COMPAT_API(0) */
 873
 874 #endif /* #ifndef LTTNG_UST_TRACEPOINT_EVENT */
 875
 876 #ifndef LTTNG_UST_TRACEPOINT_LOGLEVEL
 877
 878 /*
 879  * Tracepoint Loglevels
 880  *
 881  * Typical use of these loglevels:
 882  *
 883  * The loglevels go from 0 to 14. Higher numbers imply the most
 884  * verbosity (higher event throughput expected.
 885  *
 886  * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
 887  * semantic. Loglevels 7 through 13 offer more fine-grained selection of
 888  * debug information.
 889  *
 890  * LTTNG_UST_TRACEPOINT_LOGLEVEL_EMERG           0
 891  * system is unusable
 892  *
 893  * LTTNG_UST_TRACEPOINT_LOGLEVEL_ALERT           1
 894  * action must be taken immediately
 895  *
 896  * LTTNG_UST_TRACEPOINT_LOGLEVEL_CRIT            2
 897  * critical conditions
 898  *
 899  * LTTNG_UST_TRACEPOINT_LOGLEVEL_ERR             3
 900  * error conditions
 901  *
 902  * LTTNG_UST_TRACEPOINT_LOGLEVEL_WARNING         4
 903  * warning conditions
 904  *
 905  * LTTNG_UST_TRACEPOINT_LOGLEVEL_NOTICE          5
 906  * normal, but significant, condition
 907  *
 908  * LTTNG_UST_TRACEPOINT_LOGLEVEL_INFO            6
 909  * informational message
 910  *
 911  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_SYSTEM    7
 912  * debug information with system-level scope (set of programs)
 913  *
 914  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROGRAM   8
 915  * debug information with program-level scope (set of processes)
 916  *
 917  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROCESS   9
 918  * debug information with process-level scope (set of modules)
 919  *
 920  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_MODULE    10
 921  * debug information with module (executable/library) scope (set of units)
 922  *
 923  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_UNIT      11
 924  * debug information with compilation unit scope (set of functions)
 925  *
 926  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_FUNCTION  12
 927  * debug information with function-level scope
 928  *
 929  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_LINE      13
 930  * debug information with line-level scope (LTTNG_UST_TRACEPOINT_EVENT default)
 931  *
 932  * LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG           14
 933  * debug-level message
 934  *
 935  * Declare tracepoint loglevels for tracepoints. A LTTNG_UST_TRACEPOINT_EVENT
 936  * should be declared prior to the the LTTNG_UST_TRACEPOINT_LOGLEVEL for a given
 937  * tracepoint name. The first field is the provider name, the second
 938  * field is the name of the tracepoint, the third field is the loglevel
 939  * name.
 940  *
 941  *      LTTNG_UST_TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
 942  *              < loglevel_name >)
 943  *
 944  * The LTTNG_UST_TRACEPOINT_PROVIDER must be already declared before declaring a
 945  * LTTNG_UST_TRACEPOINT_LOGLEVEL.
 946  */
 947
 948 enum {
 949         LTTNG_UST_TRACEPOINT_LOGLEVEL_EMERG             = 0,
 950         LTTNG_UST_TRACEPOINT_LOGLEVEL_ALERT             = 1,
 951         LTTNG_UST_TRACEPOINT_LOGLEVEL_CRIT              = 2,
 952         LTTNG_UST_TRACEPOINT_LOGLEVEL_ERR               = 3,
 953         LTTNG_UST_TRACEPOINT_LOGLEVEL_WARNING           = 4,
 954         LTTNG_UST_TRACEPOINT_LOGLEVEL_NOTICE            = 5,
 955         LTTNG_UST_TRACEPOINT_LOGLEVEL_INFO              = 6,
 956         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_SYSTEM      = 7,
 957         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROGRAM     = 8,
 958         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROCESS     = 9,
 959         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_MODULE      = 10,
 960         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_UNIT        = 11,
 961         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_FUNCTION    = 12,
 962         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_LINE        = 13,
 963         LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG             = 14,
 964 };
 965
 966 #define LTTNG_UST_TRACEPOINT_LOGLEVEL(provider, name, loglevel)
 967
 968 #if LTTNG_UST_COMPAT_API(0)
 969 #define TRACEPOINT_LOGLEVEL     LTTNG_UST_TRACEPOINT_LOGLEVEL
 970
 971 #define TRACE_EMERG             LTTNG_UST_TRACEPOINT_LOGLEVEL_EMERG
 972 #define TRACE_ALERT             LTTNG_UST_TRACEPOINT_LOGLEVEL_ALERT
 973 #define TRACE_CRIT              LTTNG_UST_TRACEPOINT_LOGLEVEL_CRIT
 974 #define TRACE_ERR               LTTNG_UST_TRACEPOINT_LOGLEVEL_ERR
 975 #define TRACE_WARNING           LTTNG_UST_TRACEPOINT_LOGLEVEL_WARNING
 976 #define TRACE_NOTICE            LTTNG_UST_TRACEPOINT_LOGLEVEL_NOTICE
 977 #define TRACE_INFO              LTTNG_UST_TRACEPOINT_LOGLEVEL_INFO
 978 #define TRACE_DEBUG_SYSTEM      LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_SYSTEM
 979 #define TRACE_DEBUG_PROGRAM     LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROGRAM
 980 #define TRACE_DEBUG_PROCESS     LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_PROCESS
 981 #define TRACE_DEBUG_MODULE      LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_MODULE
 982 #define TRACE_DEBUG_UNIT        LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_UNIT
 983 #define TRACE_DEBUG_FUNCTION    LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_FUNCTION
 984 #define TRACE_DEBUG_LINE        LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG_LINE
 985 #define TRACE_DEBUG             LTTNG_UST_TRACEPOINT_LOGLEVEL_DEBUG
 986 #endif
 987
 988 #endif /* #ifndef LTTNG_UST_TRACEPOINT_LOGLEVEL */
 989
 990 #ifndef LTTNG_UST_TRACEPOINT_MODEL_EMF_URI
 991
 992 #define LTTNG_UST_TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
 993
 994 #if LTTNG_UST_COMPAT_API(0)
 995 #define TRACEPOINT_MODEL_EMF_URI LTTNG_UST_TRACEPOINT_MODEL_EMF_URI
 996 #endif
 997
 998 #endif /* #ifndef LTTNG_UST_TRACEPOINT_MODEL_EMF_URI */