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 #ifndef LTTNG_PACKED
  25 #error "LTTNG_PACKED should be defined"
  26 #endif
  27
  28 #ifdef __cplusplus
  29 extern "C" {
  30 #endif
  31
  32 #define LTTNG_UST_UUID_LEN              16
  33
  34 /*
  35  * Tracepoint provider version. Compatibility based on the major number.
  36  * Older tracepoint providers can always register to newer lttng-ust
  37  * library, but the opposite is rejected: a newer tracepoint provider is
  38  * rejected by an older lttng-ust library.
  39  */
  40 #define LTTNG_UST_PROVIDER_MAJOR        2
  41 #define LTTNG_UST_PROVIDER_MINOR        0
  42
  43 struct lttng_channel;
  44 struct lttng_session;
  45 struct lttng_ust_lib_ring_buffer_ctx;
  46 struct lttng_ust_event_field;
  47 struct lttng_event_notifier_group;
  48
  49 /*
  50  * Data structures used by tracepoint event declarations, and by the
  51  * tracer. Those structures have padding for future extension.
  52  */
  53
  54 /* Type description */
  55
  56 /* Update the astract_types name table in lttng-types.c along with this enum */
  57 enum lttng_abstract_types {
  58         atype_integer,
  59         atype_string,
  60         atype_float,
  61         atype_dynamic,
  62         atype_enum_nestable,
  63         atype_array_nestable,
  64         atype_sequence_nestable,
  65         atype_struct_nestable,
  66         NR_ABSTRACT_TYPES,
  67 };
  68
  69 /* Update the string_encodings name table in lttng-types.c along with this enum */
  70 enum lttng_string_encodings {
  71         lttng_encode_none = 0,
  72         lttng_encode_UTF8 = 1,
  73         lttng_encode_ASCII = 2,
  74         NR_STRING_ENCODINGS,
  75 };
  76
  77 struct lttng_enum_value {
  78         unsigned long long value;
  79         unsigned int signedness:1;
  80 };
  81
  82 enum lttng_enum_entry_options {
  83         LTTNG_ENUM_ENTRY_OPTION_IS_AUTO = 1U << 0,
  84 };
  85
  86 /*
  87  * Enumeration entry description
  88  *
  89  * IMPORTANT: this structure is part of the ABI between the probe and
  90  * UST. Fields need to be only added at the end, never reordered, never
  91  * removed.
  92  *
  93  * The field @struct_size should be used to determine the size of the
  94  * structure. It should be queried before using additional fields added
  95  * at the end of the structure.
  96  */
  97
  98 struct lttng_ust_enum_entry {
  99         uint32_t struct_size;
 100
 101         struct lttng_enum_value start, end; /* start and end are inclusive */
 102         const char *string;
 103         unsigned int options;
 104
 105         /* End of base ABI. Fields below should be used after checking struct_size. */
 106 };
 107
 108 #define __type_integer(_type, _byte_order, _base, _encoding)    \
 109         {                                                       \
 110           .atype = atype_integer,                               \
 111           .u =                                                  \
 112                 {                                               \
 113                   .integer =                                    \
 114                         {                                       \
 115                           .size = sizeof(_type) * CHAR_BIT,     \
 116                           .alignment = lttng_alignof(_type) * CHAR_BIT, \
 117                           .signedness = lttng_is_signed_type(_type), \
 118                           .reverse_byte_order = _byte_order != BYTE_ORDER, \
 119                           .base = _base,                        \
 120                           .encoding = lttng_encode_##_encoding, \
 121                         }                                       \
 122                 },                                              \
 123         }                                                       \
 124
 125 #define LTTNG_UST_INTEGER_TYPE_PADDING  24
 126 struct lttng_integer_type {
 127         unsigned int size;              /* in bits */
 128         unsigned short alignment;       /* in bits */
 129         unsigned int signedness:1;
 130         unsigned int reverse_byte_order:1;
 131         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
 132         enum lttng_string_encodings encoding;
 133         char padding[LTTNG_UST_INTEGER_TYPE_PADDING];
 134 };
 135
 136 /*
 137  * Only float and double are supported. long double is not supported at
 138  * the moment.
 139  */
 140 #define _float_mant_dig(_type)                                          \
 141         (sizeof(_type) == sizeof(float) ? FLT_MANT_DIG                  \
 142                 : (sizeof(_type) == sizeof(double) ? DBL_MANT_DIG       \
 143                 : 0))
 144
 145 #define __type_float(_type)                                     \
 146         {                                                       \
 147           .atype = atype_float,                                 \
 148           .u =                                                  \
 149                 {                                               \
 150                   ._float =                                     \
 151                         {                                       \
 152                           .exp_dig = sizeof(_type) * CHAR_BIT   \
 153                                           - _float_mant_dig(_type), \
 154                           .mant_dig = _float_mant_dig(_type),   \
 155                           .alignment = lttng_alignof(_type) * CHAR_BIT, \
 156                           .reverse_byte_order = BYTE_ORDER != FLOAT_WORD_ORDER, \
 157                         }                                       \
 158                 }                                               \
 159         }                                                       \
 160
 161 #define LTTNG_UST_FLOAT_TYPE_PADDING    24
 162 struct lttng_float_type {
 163         unsigned int exp_dig;           /* exponent digits, in bits */
 164         unsigned int mant_dig;          /* mantissa digits, in bits */
 165         unsigned short alignment;       /* in bits */
 166         unsigned int reverse_byte_order:1;
 167         char padding[LTTNG_UST_FLOAT_TYPE_PADDING];
 168 };
 169
 170 #define LTTNG_UST_TYPE_PADDING  128
 171 struct lttng_type {
 172         enum lttng_abstract_types atype;
 173         union {
 174                 /* provider ABI 2.0 */
 175                 struct lttng_integer_type integer;
 176                 struct lttng_float_type _float;
 177                 struct {
 178                         enum lttng_string_encodings encoding;
 179                 } string;
 180                 struct {
 181                         const struct lttng_ust_enum_desc *desc; /* Enumeration mapping */
 182                         struct lttng_type *container_type;
 183                 } enum_nestable;
 184                 struct {
 185                         const struct lttng_type *elem_type;
 186                         unsigned int length;                    /* Num. elems. */
 187                         unsigned int alignment;
 188                 } array_nestable;
 189                 struct {
 190                         const char *length_name;                /* Length field name. */
 191                         const struct lttng_type *elem_type;
 192                         unsigned int alignment;                 /* Alignment before elements. */
 193                 } sequence_nestable;
 194                 struct {
 195                         unsigned int nr_fields;
 196                         const struct lttng_ust_event_field **fields; /* Array of pointers to fields. */
 197                         unsigned int alignment;
 198                 } struct_nestable;
 199
 200                 char padding[LTTNG_UST_TYPE_PADDING];
 201         } u;
 202 };
 203
 204 /*
 205  * Enumeration description
 206  *
 207  * IMPORTANT: this structure is part of the ABI between the probe and
 208  * UST. Fields need to be only added at the end, never reordered, never
 209  * removed.
 210  *
 211  * The field @struct_size should be used to determine the size of the
 212  * structure. It should be queried before using additional fields added
 213  * at the end of the structure.
 214  */
 215
 216 struct lttng_ust_enum_desc {
 217         uint32_t struct_size;
 218
 219         const char *name;
 220         const struct lttng_ust_enum_entry **entries;
 221         unsigned int nr_entries;
 222
 223         /* End of base ABI. Fields below should be used after checking struct_size. */
 224 };
 225
 226 /*
 227  * Event field description
 228  *
 229  * IMPORTANT: this structure is part of the ABI between the probe and
 230  * UST. Fields need to be only added at the end, never reordered, never
 231  * removed.
 232  *
 233  * The field @struct_size should be used to determine the size of the
 234  * structure. It should be queried before using additional fields added
 235  * at the end of the structure.
 236  */
 237
 238 struct lttng_ust_event_field {
 239         uint32_t struct_size;
 240
 241         const char *name;
 242         struct lttng_type type;
 243         unsigned int nowrite:1,         /* do not write into trace */
 244                 nofilter:1;             /* do not consider for filter */
 245
 246         /* End of base ABI. Fields below should be used after checking struct_size. */
 247 };
 248
 249
 250 /*
 251  * IMPORTANT: this structure is part of the ABI between the probe and
 252  * UST. Fields need to be only added at the end, never reordered, never
 253  * removed.
 254  *
 255  * The field @struct_size should be used to determine the size of the
 256  * structure. It should be queried before using additional fields added
 257  * at the end of the structure.
 258  */
 259 struct lttng_ust_event_desc {
 260         uint32_t struct_size;                   /* Size of this structure. */
 261
 262         const char *name;
 263         void (*probe_callback)(void);
 264         const struct lttng_event_ctx *ctx;      /* context */
 265         const struct lttng_ust_event_field **fields;    /* event payload */
 266         unsigned int nr_fields;
 267         const int **loglevel;
 268         const char *signature;                  /* Argument types/names received */
 269         const char **model_emf_uri;
 270
 271         /* End of base ABI. Fields below should be used after checking struct_size. */
 272 };
 273
 274 /*
 275  * IMPORTANT: this structure is part of the ABI between the probe and
 276  * UST. Fields need to be only added at the end, never reordered, never
 277  * removed.
 278  *
 279  * The field @struct_size should be used to determine the size of the
 280  * structure. It should be queried before using additional fields added
 281  * at the end of the structure.
 282  */
 283 struct lttng_ust_probe_desc {
 284         uint32_t struct_size;                   /* Size of this structure. */
 285
 286         const char *provider;
 287         const struct lttng_ust_event_desc **event_desc;
 288         unsigned int nr_events;
 289         struct cds_list_head head;              /* chain registered probes */
 290         struct cds_list_head lazy_init_head;
 291         int lazy;                               /* lazy registration */
 292         uint32_t major;
 293         uint32_t minor;
 294
 295         /* End of base ABI. Fields below should be used after checking struct_size. */
 296 };
 297
 298 /* Data structures used by the tracer. */
 299
 300 /*
 301  * Bytecode interpreter return value masks.
 302  */
 303 enum lttng_bytecode_interpreter_ret {
 304         LTTNG_INTERPRETER_DISCARD = 0,
 305         LTTNG_INTERPRETER_RECORD_FLAG = (1ULL << 0),
 306         /* Other bits are kept for future use. */
 307 };
 308
 309 struct lttng_interpreter_output;
 310 struct lttng_ust_bytecode_runtime_private;
 311
 312 /*
 313  * IMPORTANT: this structure is part of the ABI between the probe and
 314  * UST. Fields need to be only added at the end, never reordered, never
 315  * removed.
 316  *
 317  * The field @struct_size should be used to determine the size of the
 318  * structure. It should be queried before using additional fields added
 319  * at the end of the structure.
 320  */
 321 struct lttng_ust_bytecode_runtime {
 322         uint32_t struct_size;                   /* Size of this structure. */
 323
 324         struct lttng_ust_bytecode_runtime_private *priv;
 325         /* Associated bytecode */
 326         union {
 327                 uint64_t (*filter)(void *interpreter_data,
 328                                 const char *interpreter_stack_data);
 329                 uint64_t (*capture)(void *interpreter_data,
 330                                 const char *interpreter_stack_data,
 331                                 struct lttng_interpreter_output *interpreter_output);
 332         } interpreter_funcs;
 333         struct cds_list_head node;      /* list of bytecode runtime in event */
 334
 335         /* End of base ABI. Fields below should be used after checking struct_size. */
 336 };
 337
 338 /*
 339  * lttng_event structure is referred to by the tracing fast path. It
 340  * must be kept small.
 341  *
 342  * IMPORTANT: this structure is part of the ABI between the probe and
 343  * UST. Fields need to be only added at the end, never reordered, never
 344  * removed.
 345  */
 346
 347 struct lttng_ust_ctx;
 348 struct lttng_ust_event_common_private;
 349
 350 enum lttng_ust_event_type {
 351         LTTNG_UST_EVENT_TYPE_RECORDER = 0,
 352         LTTNG_UST_EVENT_TYPE_NOTIFIER = 1,
 353 };
 354
 355 /*
 356  * IMPORTANT: this structure is part of the ABI between the probe and
 357  * UST. Fields need to be only added at the end, never reordered, never
 358  * removed.
 359  *
 360  * struct lttng_ust_event_common is the common ancestor of the various
 361  * public event actions. Inheritance is done by composition: The parent
 362  * has a pointer to its child, and the child has a pointer to its
 363  * parent. Inheritance of those public structures is done by composition
 364  * to ensure both parent and child structures can be extended.
 365  *
 366  * The field @struct_size should be used to determine the size of the
 367  * structure. It should be queried before using additional fields added
 368  * at the end of the structure.
 369  */
 370 struct lttng_ust_event_common {
 371         uint32_t struct_size;                           /* Size of this structure. */
 372
 373         struct lttng_ust_event_common_private *priv;    /* Private event interface */
 374
 375         enum lttng_ust_event_type type;
 376         void *child;                                    /* Pointer to child, for inheritance by aggregation. */
 377
 378         int enabled;
 379         int has_enablers_without_bytecode;
 380         /* list of struct lttng_ust_bytecode_runtime, sorted by seqnum */
 381         struct cds_list_head filter_bytecode_runtime_head;
 382
 383         /* End of base ABI. Fields below should be used after checking struct_size. */
 384 };
 385
 386 struct lttng_ust_event_recorder_private;
 387
 388 /*
 389  * IMPORTANT: this structure is part of the ABI between the probe and
 390  * UST. Fields need to be only added at the end, never reordered, never
 391  * removed.
 392  *
 393  * struct lttng_ust_event_recorder is the action for recording events
 394  * into a ring buffer. It inherits from struct lttng_ust_event_common
 395  * by composition to ensure both parent and child structure are
 396  * extensible.
 397  *
 398  * The field @struct_size should be used to determine the size of the
 399  * structure. It should be queried before using additional fields added
 400  * at the end of the structure.
 401  */
 402 struct lttng_ust_event_recorder {
 403         uint32_t struct_size;                           /* Size of this structure. */
 404
 405         struct lttng_ust_event_common *parent;          /* Inheritance by aggregation. */
 406         struct lttng_ust_event_recorder_private *priv;  /* Private event record interface */
 407
 408         unsigned int id;
 409         struct lttng_channel *chan;
 410         struct lttng_ust_ctx *ctx;
 411
 412         /* End of base ABI. Fields below should be used after checking struct_size. */
 413 };
 414
 415 struct lttng_ust_event_notifier_private;
 416
 417 /*
 418  * IMPORTANT: this structure is part of the ABI between the probe and
 419  * UST. Fields need to be only added at the end, never reordered, never
 420  * removed.
 421  *
 422  * struct lttng_ust_event_notifier is the action for sending
 423  * notifications. It inherits from struct lttng_ust_event_common
 424  * by composition to ensure both parent and child structure are
 425  * extensible.
 426  *
 427  * The field @struct_size should be used to determine the size of the
 428  * structure. It should be queried before using additional fields added
 429  * at the end of the structure.
 430  */
 431 struct lttng_ust_event_notifier {
 432         uint32_t struct_size;                           /* Size of this structure. */
 433
 434         struct lttng_ust_event_common *parent;          /* Inheritance by aggregation. */
 435         struct lttng_ust_event_notifier_private *priv;  /* Private event notifier interface */
 436
 437         void (*notification_send)(struct lttng_ust_event_notifier *event_notifier,
 438                 const char *stack_data);
 439         struct cds_list_head capture_bytecode_runtime_head;
 440
 441         /* End of base ABI. Fields below should be used after checking struct_size. */
 442 };
 443
 444 struct lttng_ust_lib_ring_buffer_channel;
 445 struct lttng_ust_shm_handle;
 446
 447 /*
 448  * IMPORTANT: this structure is part of the ABI between the probe and
 449  * UST. Fields need to be only added at the end, never reordered, never
 450  * removed.
 451  *
 452  * The field @struct_size should be used to determine the size of the
 453  * structure. It should be queried before using additional fields added
 454  * at the end of the structure.
 455  */
 456 struct lttng_ust_channel_ops {
 457         uint32_t struct_size;
 458
 459         struct lttng_channel *(*channel_create)(const char *name,
 460                         void *buf_addr,
 461                         size_t subbuf_size, size_t num_subbuf,
 462                         unsigned int switch_timer_interval,
 463                         unsigned int read_timer_interval,
 464                         unsigned char *uuid,
 465                         uint32_t chan_id,
 466                         const int *stream_fds, int nr_stream_fds,
 467                         int64_t blocking_timeout);
 468         void (*channel_destroy)(struct lttng_channel *chan);
 469         int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 470                              uint32_t event_id);
 471         void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx);
 472         void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 473                         const void *src, size_t len);
 474         /*
 475          * packet_avail_size returns the available size in the current
 476          * packet. Note that the size returned is only a hint, since it
 477          * may change due to concurrent writes.
 478          */
 479         size_t (*packet_avail_size)(struct lttng_ust_lib_ring_buffer_channel *chan,
 480                                     struct lttng_ust_shm_handle *handle);
 481         int (*is_finalized)(struct lttng_ust_lib_ring_buffer_channel *chan);
 482         int (*is_disabled)(struct lttng_ust_lib_ring_buffer_channel *chan);
 483         int (*flush_buffer)(struct lttng_ust_lib_ring_buffer_channel *chan,
 484                             struct lttng_ust_shm_handle *handle);
 485         void (*event_strcpy)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 486                         const char *src, size_t len);
 487
 488         /* End of base ABI. Fields below should be used after checking struct_size. */
 489 };
 490
 491 /*
 492  * IMPORTANT: this structure is part of the ABI between the probe and
 493  * UST. Fields need to be only added at the end, never reordered, never
 494  * removed.
 495  */
 496 struct lttng_channel {
 497         /*
 498          * The pointers located in this private data are NOT safe to be
 499          * dereferenced by the consumer. The only operations the
 500          * consumer process is designed to be allowed to do is to read
 501          * and perform subbuffer flush.
 502          */
 503         struct lttng_ust_lib_ring_buffer_channel *chan; /* Channel buffers */
 504         int enabled;
 505         struct lttng_ust_ctx *ctx;
 506         /* Event ID management */
 507         struct lttng_session *session;
 508         int objd;                       /* Object associated to channel */
 509         struct cds_list_head node;      /* Channel list in session */
 510         const struct lttng_ust_channel_ops *ops;
 511         int header_type;                /* 0: unset, 1: compact, 2: large */
 512         struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
 513
 514         /* Channel ID */
 515         unsigned int id;
 516         enum lttng_ust_abi_chan_type type;
 517         unsigned char uuid[LTTNG_UST_UUID_LEN]; /* Trace session unique ID */
 518         int tstate:1;                   /* Transient enable state */
 519 };
 520
 521 /*
 522  * IMPORTANT: this structure is part of the ABI between the probe and
 523  * UST. Fields need to be only added at the end, never reordered, never
 524  * removed.
 525  *
 526  * The field @struct_size should be used to determine the size of the
 527  * structure. It should be queried before using additional fields added
 528  * at the end of the structure.
 529  */
 530 struct lttng_ust_stack_ctx {
 531         uint32_t struct_size;                   /* Size of this structure */
 532
 533         struct lttng_ust_event_recorder *event_recorder;
 534         struct lttng_ust_ctx *chan_ctx; /* RCU dereferenced. */
 535         struct lttng_ust_ctx *event_ctx;        /* RCU dereferenced. */
 536
 537         /* End of base ABI. Fields below should be used after checking struct_size. */
 538 };
 539
 540 struct lttng_ust_session_private;
 541
 542 /*
 543  * IMPORTANT: this structure is part of the ABI between the probe and
 544  * UST. Fields need to be only added at the end, never reordered, never
 545  * removed.
 546  *
 547  * The field @struct_size should be used to determine the size of the
 548  * structure. It should be queried before using additional fields added
 549  * at the end of the structure.
 550  */
 551 struct lttng_session {
 552         uint32_t struct_size;                   /* Size of this structure */
 553
 554         struct lttng_ust_session_private *priv; /* Private session interface */
 555
 556         int active;                             /* Is trace session active ? */
 557
 558         /* End of base ABI. Fields below should be used after checking struct_size. */
 559 };
 560
 561 int lttng_ust_probe_register(struct lttng_ust_probe_desc *desc);
 562 void lttng_ust_probe_unregister(struct lttng_ust_probe_desc *desc);
 563
 564 /*
 565  * Applications that change their procname and need the new value to be
 566  * reflected in the procname event context have to call this function to clear
 567  * the internally cached value. This should not be called from a signal
 568  * handler.
 569  */
 570 void lttng_ust_context_procname_reset(void);
 571
 572 #ifdef __cplusplus
 573 }
 574 #endif
 575
 576 #endif /* _LTTNG_UST_EVENTS_H */