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         const char *name;
 262         void (*probe_callback)(void);
 263         const struct lttng_event_ctx *ctx;      /* context */
 264         const 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         const 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_bytecode_interpreter_ret {
 303         LTTNG_INTERPRETER_DISCARD = 0,
 304         LTTNG_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_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         struct lttng_ust_event_common_private *priv;    /* Private event interface */
 372
 373         enum lttng_ust_event_type type;
 374         void *child;                                    /* Pointer to child, for inheritance by aggregation. */
 375
 376         int enabled;
 377         int has_enablers_without_bytecode;
 378         /* list of struct lttng_ust_bytecode_runtime, sorted by seqnum */
 379         struct cds_list_head filter_bytecode_runtime_head;
 380
 381         /* End of base ABI. Fields below should be used after checking struct_size. */
 382 };
 383
 384 struct lttng_ust_event_recorder_private;
 385
 386 /*
 387  * IMPORTANT: this structure is part of the ABI between the probe and
 388  * UST. Fields need to be only added at the end, never reordered, never
 389  * removed.
 390  *
 391  * struct lttng_ust_event_recorder is the action for recording events
 392  * into a ring buffer. It inherits from struct lttng_ust_event_common
 393  * by composition to ensure both parent and child structure are
 394  * extensible.
 395  *
 396  * The field @struct_size should be used to determine the size of the
 397  * structure. It should be queried before using additional fields added
 398  * at the end of the structure.
 399  */
 400 struct lttng_ust_event_recorder {
 401         uint32_t struct_size;                           /* Size of this structure. */
 402         struct lttng_ust_event_common *parent;          /* Inheritance by aggregation. */
 403         struct lttng_ust_event_recorder_private *priv;  /* Private event record interface */
 404
 405         unsigned int id;
 406         struct lttng_channel *chan;
 407         struct lttng_ctx *ctx;
 408
 409         /* End of base ABI. Fields below should be used after checking struct_size. */
 410 };
 411
 412 struct lttng_ust_event_notifier_private;
 413
 414 /*
 415  * IMPORTANT: this structure is part of the ABI between the probe and
 416  * UST. Fields need to be only added at the end, never reordered, never
 417  * removed.
 418  *
 419  * struct lttng_ust_event_notifier is the action for sending
 420  * notifications. It inherits from struct lttng_ust_event_common
 421  * by composition to ensure both parent and child structure are
 422  * extensible.
 423  *
 424  * The field @struct_size should be used to determine the size of the
 425  * structure. It should be queried before using additional fields added
 426  * at the end of the structure.
 427  */
 428 struct lttng_ust_event_notifier {
 429         uint32_t struct_size;                           /* Size of this structure. */
 430
 431         struct lttng_ust_event_common *parent;          /* Inheritance by aggregation. */
 432         struct lttng_ust_event_notifier_private *priv;  /* Private event notifier interface */
 433
 434         void (*notification_send)(struct lttng_ust_event_notifier *event_notifier,
 435                 const char *stack_data);
 436         struct cds_list_head capture_bytecode_runtime_head;
 437
 438         /* End of base ABI. Fields below should be used after checking struct_size. */
 439 };
 440
 441 struct channel;
 442 struct lttng_ust_shm_handle;
 443
 444 /*
 445  * IMPORTANT: this structure is part of the ABI between the probe and
 446  * UST. Fields need to be only added at the end, never reordered, never
 447  * removed.
 448  *
 449  * The field @struct_size should be used to determine the size of the
 450  * structure. It should be queried before using additional fields added
 451  * at the end of the structure.
 452  */
 453 struct lttng_ust_channel_ops {
 454         uint32_t struct_size;
 455
 456         struct lttng_channel *(*channel_create)(const char *name,
 457                         void *buf_addr,
 458                         size_t subbuf_size, size_t num_subbuf,
 459                         unsigned int switch_timer_interval,
 460                         unsigned int read_timer_interval,
 461                         unsigned char *uuid,
 462                         uint32_t chan_id,
 463                         const int *stream_fds, int nr_stream_fds,
 464                         int64_t blocking_timeout);
 465         void (*channel_destroy)(struct lttng_channel *chan);
 466         int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 467                              uint32_t event_id);
 468         void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx);
 469         void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 470                         const void *src, size_t len);
 471         /*
 472          * packet_avail_size returns the available size in the current
 473          * packet. Note that the size returned is only a hint, since it
 474          * may change due to concurrent writes.
 475          */
 476         size_t (*packet_avail_size)(struct channel *chan,
 477                                     struct lttng_ust_shm_handle *handle);
 478         int (*is_finalized)(struct channel *chan);
 479         int (*is_disabled)(struct channel *chan);
 480         int (*flush_buffer)(struct channel *chan, struct lttng_ust_shm_handle *handle);
 481         void (*event_strcpy)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 482                         const char *src, size_t len);
 483
 484         /* End of base ABI. Fields below should be used after checking struct_size. */
 485 };
 486
 487 /*
 488  * IMPORTANT: this structure is part of the ABI between the probe and
 489  * UST. Fields need to be only added at the end, never reordered, never
 490  * removed.
 491  */
 492 struct lttng_channel {
 493         /*
 494          * The pointers located in this private data are NOT safe to be
 495          * dereferenced by the consumer. The only operations the
 496          * consumer process is designed to be allowed to do is to read
 497          * and perform subbuffer flush.
 498          */
 499         struct channel *chan;           /* Channel buffers */
 500         int enabled;
 501         struct lttng_ctx *ctx;
 502         /* Event ID management */
 503         struct lttng_session *session;
 504         int objd;                       /* Object associated to channel */
 505         struct cds_list_head node;      /* Channel list in session */
 506         const struct lttng_ust_channel_ops *ops;
 507         int header_type;                /* 0: unset, 1: compact, 2: large */
 508         struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
 509
 510         /* Channel ID */
 511         unsigned int id;
 512         enum lttng_ust_abi_chan_type type;
 513         unsigned char uuid[LTTNG_UST_UUID_LEN]; /* Trace session unique ID */
 514         int tstate:1;                   /* Transient enable state */
 515 };
 516
 517 /*
 518  * IMPORTANT: this structure is part of the ABI between the probe and
 519  * UST. Fields need to be only added at the end, never reordered, never
 520  * removed.
 521  *
 522  * The field @struct_size should be used to determine the size of the
 523  * structure. It should be queried before using additional fields added
 524  * at the end of the structure.
 525  */
 526 struct lttng_ust_stack_ctx {
 527         uint32_t struct_size;                   /* Size of this structure */
 528
 529         struct lttng_ust_event_recorder *event_recorder;
 530         struct lttng_ctx *chan_ctx;     /* RCU dereferenced. */
 531         struct lttng_ctx *event_ctx;    /* RCU dereferenced. */
 532
 533         /* End of base ABI. Fields below should be used after checking struct_size. */
 534 };
 535
 536 struct lttng_ust_session_private;
 537
 538 /*
 539  * IMPORTANT: this structure is part of the ABI between the probe and
 540  * UST. Fields need to be only added at the end, never reordered, never
 541  * removed.
 542  *
 543  * The field @struct_size should be used to determine the size of the
 544  * structure. It should be queried before using additional fields added
 545  * at the end of the structure.
 546  */
 547 struct lttng_session {
 548         uint32_t struct_size;                   /* Size of this structure */
 549         struct lttng_ust_session_private *priv; /* Private session interface */
 550
 551         int active;                             /* Is trace session active ? */
 552
 553         /* End of base ABI. Fields below should be used after checking struct_size. */
 554 };
 555
 556 int lttng_ust_probe_register(struct lttng_ust_probe_desc *desc);
 557 void lttng_ust_probe_unregister(struct lttng_ust_probe_desc *desc);
 558
 559 /*
 560  * Applications that change their procname and need the new value to be
 561  * reflected in the procname event context have to call this function to clear
 562  * the internally cached value. This should not be called from a signal
 563  * handler.
 564  */
 565 void lttng_ust_context_procname_reset(void);
 566
 567 #ifdef __cplusplus
 568 }
 569 #endif
 570
 571 #endif /* _LTTNG_UST_EVENTS_H */