include/lttng/ust-events.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * Holds LTTng per-session event registry.
   7  */
   8
   9 #ifndef _LTTNG_UST_EVENTS_H
  10 #define _LTTNG_UST_EVENTS_H
  11
  12 #include <urcu/list.h>
  13 #include <urcu/hlist.h>
  14 #include <stddef.h>
  15 #include <stdint.h>
  16 #include <lttng/ust-abi.h>
  17 #include <lttng/ust-tracer.h>
  18 #include <lttng/ust-endian.h>
  19 #include <float.h>
  20 #include <errno.h>
  21 #include <urcu/ref.h>
  22 #include <pthread.h>
  23
  24 #ifdef __cplusplus
  25 extern "C" {
  26 #endif
  27
  28 #define LTTNG_UST_UUID_LEN              16
  29
  30 /*
  31  * Tracepoint provider version. Compatibility based on the major number.
  32  * Older tracepoint providers can always register to newer lttng-ust
  33  * library, but the opposite is rejected: a newer tracepoint provider is
  34  * rejected by an older lttng-ust library.
  35  */
  36 #define LTTNG_UST_PROVIDER_MAJOR        2
  37 #define LTTNG_UST_PROVIDER_MINOR        0
  38
  39 struct lttng_ust_channel_buffer;
  40 struct lttng_ust_session;
  41 struct lttng_ust_lib_ring_buffer_ctx;
  42 struct lttng_ust_event_field;
  43
  44 /*
  45  * Data structures used by tracepoint event declarations, and by the
  46  * tracer.
  47  */
  48
  49 /* Type description */
  50
  51 enum lttng_ust_type {
  52         lttng_ust_type_integer,
  53         lttng_ust_type_string,
  54         lttng_ust_type_float,
  55         lttng_ust_type_dynamic,
  56         lttng_ust_type_enum,
  57         lttng_ust_type_array,
  58         lttng_ust_type_sequence,
  59         lttng_ust_type_struct,
  60         NR_LTTNG_UST_TYPE,
  61 };
  62
  63 enum lttng_ust_string_encoding {
  64         lttng_ust_string_encoding_none = 0,
  65         lttng_ust_string_encoding_UTF8 = 1,
  66         lttng_ust_string_encoding_ASCII = 2,
  67         NR_LTTNG_UST_STRING_ENCODING,
  68 };
  69
  70 struct lttng_ust_enum_value {
  71         unsigned long long value;
  72         unsigned int signedness:1;
  73 };
  74
  75 enum lttng_ust_enum_entry_option {
  76         LTTNG_UST_ENUM_ENTRY_OPTION_IS_AUTO = 1U << 0,
  77 };
  78
  79 /*
  80  * Enumeration entry description
  81  *
  82  * IMPORTANT: this structure is part of the ABI between the probe and
  83  * UST. Fields need to be only added at the end, never reordered, never
  84  * removed.
  85  *
  86  * The field @struct_size should be used to determine the size of the
  87  * structure. It should be queried before using additional fields added
  88  * at the end of the structure.
  89  */
  90
  91 struct lttng_ust_enum_entry {
  92         uint32_t struct_size;
  93
  94         struct lttng_ust_enum_value start, end; /* start and end are inclusive */
  95         const char *string;
  96         unsigned int options;
  97
  98         /* End of base ABI. Fields below should be used after checking struct_size. */
  99 };
 100
 101 /*
 102  * struct lttng_ust_type_common is fixed-size. Its children inherits
 103  * from it by embedding struct lttng_ust_type_common as its first field.
 104  */
 105 struct lttng_ust_type_common {
 106         enum lttng_ust_type type;
 107 };
 108
 109 struct lttng_ust_type_integer {
 110         struct lttng_ust_type_common parent;
 111         uint32_t struct_size;
 112         unsigned int size;              /* in bits */
 113         unsigned short alignment;       /* in bits */
 114         unsigned int signedness:1;
 115         unsigned int reverse_byte_order:1;
 116         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
 117 };
 118
 119 #define lttng_ust_type_integer_define(_type, _byte_order, _base)        \
 120         ((struct lttng_ust_type_common *) __LTTNG_COMPOUND_LITERAL(struct lttng_ust_type_integer, { \
 121                 .parent = {                                             \
 122                         .type = lttng_ust_type_integer,                 \
 123                 },                                                      \
 124                 .struct_size = sizeof(struct lttng_ust_type_integer),   \
 125                 .size = sizeof(_type) * CHAR_BIT,                       \
 126                 .alignment = lttng_alignof(_type) * CHAR_BIT,           \
 127                 .signedness = lttng_is_signed_type(_type),              \
 128                 .reverse_byte_order = _byte_order != BYTE_ORDER,        \
 129                 .base = _base,                                          \
 130         }))
 131
 132 struct lttng_ust_type_float {
 133         struct lttng_ust_type_common parent;
 134         uint32_t struct_size;
 135         unsigned int exp_dig;           /* exponent digits, in bits */
 136         unsigned int mant_dig;          /* mantissa digits, in bits */
 137         unsigned short alignment;       /* in bits */
 138         unsigned int reverse_byte_order:1;
 139 };
 140
 141 /*
 142  * Only float and double are supported. long double is not supported at
 143  * the moment.
 144  */
 145 #define lttng_ust_float_mant_dig(_type)                                 \
 146         (sizeof(_type) == sizeof(float) ? FLT_MANT_DIG                  \
 147                 : (sizeof(_type) == sizeof(double) ? DBL_MANT_DIG       \
 148                 : 0))
 149
 150 #define lttng_ust_type_float_define(_type)                              \
 151         ((struct lttng_ust_type_common *) __LTTNG_COMPOUND_LITERAL(struct lttng_ust_type_float, { \
 152                 .parent = {                                             \
 153                         .type = lttng_ust_type_float,                   \
 154                 },                                                      \
 155                 .struct_size = sizeof(struct lttng_ust_type_float),     \
 156                 .exp_dig = sizeof(_type) * CHAR_BIT                     \
 157                         - lttng_ust_float_mant_dig(_type),              \
 158                 .mant_dig = lttng_ust_float_mant_dig(_type),            \
 159                 .alignment = lttng_alignof(_type) * CHAR_BIT,           \
 160                 .reverse_byte_order = BYTE_ORDER != FLOAT_WORD_ORDER,   \
 161         }))
 162
 163
 164 struct lttng_ust_type_string {
 165         struct lttng_ust_type_common parent;
 166         uint32_t struct_size;
 167         enum lttng_ust_string_encoding encoding;
 168 };
 169
 170 struct lttng_ust_type_enum {
 171         struct lttng_ust_type_common parent;
 172         uint32_t struct_size;
 173         struct lttng_ust_enum_desc *desc;       /* Enumeration mapping */
 174         struct lttng_ust_type_common *container_type;
 175 };
 176
 177 struct lttng_ust_type_array {
 178         struct lttng_ust_type_common parent;
 179         uint32_t struct_size;
 180         struct lttng_ust_type_common *elem_type;
 181         unsigned int length;                    /* Num. elems. */
 182         unsigned int alignment;
 183         enum lttng_ust_string_encoding encoding;
 184 };
 185
 186 struct lttng_ust_type_sequence {
 187         struct lttng_ust_type_common parent;
 188         uint32_t struct_size;
 189         const char *length_name;        /* Length field name. */
 190         struct lttng_ust_type_common *elem_type;
 191         unsigned int alignment;         /* Alignment before elements. */
 192         enum lttng_ust_string_encoding encoding;
 193 };
 194
 195 struct lttng_ust_type_struct {
 196         struct lttng_ust_type_common parent;
 197         uint32_t struct_size;
 198         unsigned int nr_fields;
 199         struct lttng_ust_event_field **fields;  /* Array of pointers to fields. */
 200         unsigned int alignment;
 201 };
 202
 203 /*
 204  * Enumeration description
 205  *
 206  * IMPORTANT: this structure is part of the ABI between the probe and
 207  * UST. Fields need to be only added at the end, never reordered, never
 208  * removed.
 209  *
 210  * The field @struct_size should be used to determine the size of the
 211  * structure. It should be queried before using additional fields added
 212  * at the end of the structure.
 213  */
 214
 215 struct lttng_ust_enum_desc {
 216         uint32_t struct_size;
 217
 218         const char *name;
 219         struct lttng_ust_enum_entry **entries;
 220         unsigned int nr_entries;
 221
 222         /* End of base ABI. Fields below should be used after checking struct_size. */
 223 };
 224
 225 /*
 226  * Event field description
 227  *
 228  * IMPORTANT: this structure is part of the ABI between the probe and
 229  * UST. Fields need to be only added at the end, never reordered, never
 230  * removed.
 231  *
 232  * The field @struct_size should be used to determine the size of the
 233  * structure. It should be queried before using additional fields added
 234  * at the end of the structure.
 235  */
 236
 237 struct lttng_ust_event_field {
 238         uint32_t struct_size;
 239
 240         const char *name;
 241         struct lttng_ust_type_common *type;
 242         unsigned int nowrite:1,         /* do not write into trace */
 243                 nofilter:1;             /* do not consider for filter */
 244
 245         /* End of base ABI. Fields below should be used after checking struct_size. */
 246 };
 247
 248
 249 /*
 250  * IMPORTANT: this structure is part of the ABI between the probe and
 251  * UST. Fields need to be only added at the end, never reordered, never
 252  * removed.
 253  *
 254  * The field @struct_size should be used to determine the size of the
 255  * structure. It should be queried before using additional fields added
 256  * at the end of the structure.
 257  */
 258 struct lttng_ust_event_desc {
 259         uint32_t struct_size;                   /* Size of this structure. */
 260
 261         const char *name;
 262         void (*probe_callback)(void);
 263         struct lttng_event_ctx *ctx;            /* context */
 264         struct lttng_ust_event_field **fields;  /* event payload */
 265         unsigned int nr_fields;
 266         const int **loglevel;
 267         const char *signature;                  /* Argument types/names received */
 268         const char **model_emf_uri;
 269
 270         /* End of base ABI. Fields below should be used after checking struct_size. */
 271 };
 272
 273 /*
 274  * IMPORTANT: this structure is part of the ABI between the probe and
 275  * UST. Fields need to be only added at the end, never reordered, never
 276  * removed.
 277  *
 278  * The field @struct_size should be used to determine the size of the
 279  * structure. It should be queried before using additional fields added
 280  * at the end of the structure.
 281  */
 282 struct lttng_ust_probe_desc {
 283         uint32_t struct_size;                   /* Size of this structure. */
 284
 285         const char *provider;
 286         struct lttng_ust_event_desc **event_desc;
 287         unsigned int nr_events;
 288         struct cds_list_head head;              /* chain registered probes */
 289         struct cds_list_head lazy_init_head;
 290         int lazy;                               /* lazy registration */
 291         uint32_t major;
 292         uint32_t minor;
 293
 294         /* End of base ABI. Fields below should be used after checking struct_size. */
 295 };
 296
 297 /* Data structures used by the tracer. */
 298
 299 /*
 300  * Bytecode interpreter return value masks.
 301  */
 302 enum lttng_ust_bytecode_interpreter_ret {
 303         LTTNG_UST_BYTECODE_INTERPRETER_DISCARD = 0,
 304         LTTNG_UST_BYTECODE_INTERPRETER_RECORD_FLAG = (1ULL << 0),
 305         /* Other bits are kept for future use. */
 306 };
 307
 308 struct lttng_interpreter_output;
 309 struct lttng_ust_bytecode_runtime_private;
 310
 311 /*
 312  * IMPORTANT: this structure is part of the ABI between the probe and
 313  * UST. Fields need to be only added at the end, never reordered, never
 314  * removed.
 315  *
 316  * The field @struct_size should be used to determine the size of the
 317  * structure. It should be queried before using additional fields added
 318  * at the end of the structure.
 319  */
 320 struct lttng_ust_bytecode_runtime {
 321         uint32_t struct_size;                   /* Size of this structure. */
 322
 323         struct lttng_ust_bytecode_runtime_private *priv;
 324         /* Associated bytecode */
 325         union {
 326                 uint64_t (*filter)(void *interpreter_data,
 327                                 const char *interpreter_stack_data);
 328                 uint64_t (*capture)(void *interpreter_data,
 329                                 const char *interpreter_stack_data,
 330                                 struct lttng_interpreter_output *interpreter_output);
 331         } interpreter_funcs;
 332         struct cds_list_head node;      /* list of bytecode runtime in event */
 333
 334         /* End of base ABI. Fields below should be used after checking struct_size. */
 335 };
 336
 337 /*
 338  * lttng_event structure is referred to by the tracing fast path. It
 339  * must be kept small.
 340  *
 341  * IMPORTANT: this structure is part of the ABI between the probe and
 342  * UST. Fields need to be only added at the end, never reordered, never
 343  * removed.
 344  */
 345
 346 struct lttng_ust_ctx;
 347 struct lttng_ust_event_common_private;
 348
 349 enum lttng_ust_event_type {
 350         LTTNG_UST_EVENT_TYPE_RECORDER = 0,
 351         LTTNG_UST_EVENT_TYPE_NOTIFIER = 1,
 352 };
 353
 354 /*
 355  * IMPORTANT: this structure is part of the ABI between the probe and
 356  * UST. Fields need to be only added at the end, never reordered, never
 357  * removed.
 358  *
 359  * struct lttng_ust_event_common is the common ancestor of the various
 360  * public event actions. Inheritance is done by composition: The parent
 361  * has a pointer to its child, and the child has a pointer to its
 362  * parent. Inheritance of those public structures is done by composition
 363  * to ensure both parent and child structures can be extended.
 364  *
 365  * The field @struct_size should be used to determine the size of the
 366  * structure. It should be queried before using additional fields added
 367  * at the end of the structure.
 368  */
 369 struct lttng_ust_event_common {
 370         uint32_t struct_size;                           /* Size of this structure. */
 371
 372         struct lttng_ust_event_common_private *priv;    /* Private event interface */
 373
 374         enum lttng_ust_event_type type;
 375         void *child;                                    /* Pointer to child, for inheritance by aggregation. */
 376
 377         int enabled;
 378         int has_enablers_without_bytecode;
 379         /* list of struct lttng_ust_bytecode_runtime, sorted by seqnum */
 380         struct cds_list_head filter_bytecode_runtime_head;
 381
 382         /* End of base ABI. Fields below should be used after checking struct_size. */
 383 };
 384
 385 struct lttng_ust_event_recorder_private;
 386
 387 /*
 388  * IMPORTANT: this structure is part of the ABI between the probe and
 389  * UST. Fields need to be only added at the end, never reordered, never
 390  * removed.
 391  *
 392  * struct lttng_ust_event_recorder is the action for recording events
 393  * into a ring buffer. It inherits from struct lttng_ust_event_common
 394  * by composition to ensure both parent and child structure are
 395  * extensible.
 396  *
 397  * The field @struct_size should be used to determine the size of the
 398  * structure. It should be queried before using additional fields added
 399  * at the end of the structure.
 400  */
 401 struct lttng_ust_event_recorder {
 402         uint32_t struct_size;                           /* Size of this structure. */
 403
 404         struct lttng_ust_event_common *parent;          /* Inheritance by aggregation. */
 405         struct lttng_ust_event_recorder_private *priv;  /* Private event record interface */
 406
 407         unsigned int id;
 408         struct lttng_ust_channel_buffer *chan;
 409         struct lttng_ust_ctx *ctx;
 410
 411         /* End of base ABI. Fields below should be used after checking struct_size. */
 412 };
 413
 414 struct lttng_ust_event_notifier_private;
 415
 416 /*
 417  * IMPORTANT: this structure is part of the ABI between the probe and
 418  * UST. Fields need to be only added at the end, never reordered, never
 419  * removed.
 420  *
 421  * struct lttng_ust_event_notifier is the action for sending
 422  * notifications. It inherits from struct lttng_ust_event_common
 423  * by composition to ensure both parent and child structure are
 424  * extensible.
 425  *
 426  * The field @struct_size should be used to determine the size of the
 427  * structure. It should be queried before using additional fields added
 428  * at the end of the structure.
 429  */
 430 struct lttng_ust_event_notifier {
 431         uint32_t struct_size;                           /* Size of this structure. */
 432
 433         struct lttng_ust_event_common *parent;          /* Inheritance by aggregation. */
 434         struct lttng_ust_event_notifier_private *priv;  /* Private event notifier interface */
 435
 436         void (*notification_send)(struct lttng_ust_event_notifier *event_notifier,
 437                 const char *stack_data);
 438         struct cds_list_head capture_bytecode_runtime_head;
 439
 440         /* End of base ABI. Fields below should be used after checking struct_size. */
 441 };
 442
 443 struct lttng_ust_lib_ring_buffer_channel;
 444 struct lttng_ust_channel_ops_private;
 445
 446 /*
 447  * IMPORTANT: this structure is part of the ABI between the probe and
 448  * UST. Fields need to be only added at the end, never reordered, never
 449  * removed.
 450  *
 451  * The field @struct_size should be used to determine the size of the
 452  * structure. It should be queried before using additional fields added
 453  * at the end of the structure.
 454  */
 455 struct lttng_ust_channel_ops {
 456         uint32_t struct_size;
 457
 458         struct lttng_ust_channel_ops_private *priv;     /* Private channel ops interface */
 459
 460         int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 461                              uint32_t event_id);
 462         void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx);
 463         void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 464                         const void *src, size_t len);
 465         void (*event_strcpy)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 466                         const char *src, size_t len);
 467
 468         /* End of base ABI. Fields below should be used after checking struct_size. */
 469 };
 470
 471 enum lttng_ust_channel_type {
 472         LTTNG_UST_CHANNEL_TYPE_BUFFER = 0,
 473 };
 474
 475 struct lttng_ust_channel_common_private;
 476
 477 /*
 478  * IMPORTANT: this structure is part of the ABI between the probe and
 479  * UST. Fields need to be only added at the end, never reordered, never
 480  * removed.
 481  *
 482  * The field @struct_size should be used to determine the size of the
 483  * structure. It should be queried before using additional fields added
 484  * at the end of the structure.
 485  */
 486 struct lttng_ust_channel_common {
 487         uint32_t struct_size;                           /* Size of this structure. */
 488
 489         struct lttng_ust_channel_common_private *priv;  /* Private channel interface */
 490
 491         enum lttng_ust_channel_type type;
 492         void *child;                                    /* Pointer to child, for inheritance by aggregation. */
 493
 494         int enabled;
 495         struct lttng_ust_session *session;
 496
 497         /* End of base ABI. Fields below should be used after checking struct_size. */
 498 };
 499
 500 struct lttng_ust_channel_buffer_private;
 501
 502 /*
 503  * IMPORTANT: this structure is part of the ABI between the probe and
 504  * UST. Fields need to be only added at the end, never reordered, never
 505  * removed.
 506  *
 507  * The field @struct_size should be used to determine the size of the
 508  * structure. It should be queried before using additional fields added
 509  * at the end of the structure.
 510  */
 511 struct lttng_ust_channel_buffer {
 512         uint32_t struct_size;                           /* Size of this structure. */
 513
 514         struct lttng_ust_channel_common *parent;        /* Inheritance by aggregation. */
 515         struct lttng_ust_channel_buffer_private *priv;  /* Private channel buffer interface */
 516
 517         struct lttng_ust_channel_ops *ops;
 518         struct lttng_ust_lib_ring_buffer_channel *chan; /* Channel buffers */
 519         struct lttng_ust_shm_handle *handle;            /* shared-memory handle */
 520
 521         /* End of base ABI. Fields below should be used after checking struct_size. */
 522 };
 523
 524 /*
 525  * IMPORTANT: this structure is part of the ABI between the probe and
 526  * UST. Fields need to be only added at the end, never reordered, never
 527  * removed.
 528  *
 529  * The field @struct_size should be used to determine the size of the
 530  * structure. It should be queried before using additional fields added
 531  * at the end of the structure.
 532  */
 533 struct lttng_ust_stack_ctx {
 534         uint32_t struct_size;                   /* Size of this structure */
 535
 536         struct lttng_ust_event_recorder *event_recorder;
 537         struct lttng_ust_ctx *event_ctx;        /* RCU dereferenced. */
 538
 539         /* End of base ABI. Fields below should be used after checking struct_size. */
 540 };
 541
 542 struct lttng_ust_session_private;
 543
 544 /*
 545  * IMPORTANT: this structure is part of the ABI between the probe and
 546  * UST. Fields need to be only added at the end, never reordered, never
 547  * removed.
 548  *
 549  * The field @struct_size should be used to determine the size of the
 550  * structure. It should be queried before using additional fields added
 551  * at the end of the structure.
 552  */
 553 struct lttng_ust_session {
 554         uint32_t struct_size;                   /* Size of this structure */
 555
 556         struct lttng_ust_session_private *priv; /* Private session interface */
 557
 558         int active;                             /* Is trace session active ? */
 559
 560         /* End of base ABI. Fields below should be used after checking struct_size. */
 561 };
 562
 563 int lttng_ust_probe_register(struct lttng_ust_probe_desc *desc);
 564 void lttng_ust_probe_unregister(struct lttng_ust_probe_desc *desc);
 565
 566 /*
 567  * Applications that change their procname and need the new value to be
 568  * reflected in the procname event context have to call this function to clear
 569  * the internally cached value. This should not be called from a signal
 570  * handler.
 571  */
 572 void lttng_ust_context_procname_reset(void);
 573
 574 #ifdef __cplusplus
 575 }
 576 #endif
 577
 578 #endif /* _LTTNG_UST_EVENTS_H */