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_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 #define LTTNG_UST_ENUM_ENTRY_PADDING    16
  87 struct lttng_enum_entry {
  88         struct lttng_enum_value start, end; /* start and end are inclusive */
  89         const char *string;
  90         union {
  91                 struct {
  92                         unsigned int options;
  93                 } LTTNG_PACKED extra;
  94                 char padding[LTTNG_UST_ENUM_ENTRY_PADDING];
  95         } u;
  96 };
  97
  98 #define __type_integer(_type, _byte_order, _base, _encoding)    \
  99         {                                                       \
 100           .atype = atype_integer,                               \
 101           .u =                                                  \
 102                 {                                               \
 103                   .integer =                                    \
 104                         {                                       \
 105                           .size = sizeof(_type) * CHAR_BIT,     \
 106                           .alignment = lttng_alignof(_type) * CHAR_BIT, \
 107                           .signedness = lttng_is_signed_type(_type), \
 108                           .reverse_byte_order = _byte_order != BYTE_ORDER, \
 109                           .base = _base,                        \
 110                           .encoding = lttng_encode_##_encoding, \
 111                         }                                       \
 112                 },                                              \
 113         }                                                       \
 114
 115 #define LTTNG_UST_INTEGER_TYPE_PADDING  24
 116 struct lttng_integer_type {
 117         unsigned int size;              /* in bits */
 118         unsigned short alignment;       /* in bits */
 119         unsigned int signedness:1;
 120         unsigned int reverse_byte_order:1;
 121         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
 122         enum lttng_string_encodings encoding;
 123         char padding[LTTNG_UST_INTEGER_TYPE_PADDING];
 124 };
 125
 126 /*
 127  * Only float and double are supported. long double is not supported at
 128  * the moment.
 129  */
 130 #define _float_mant_dig(_type)                                          \
 131         (sizeof(_type) == sizeof(float) ? FLT_MANT_DIG                  \
 132                 : (sizeof(_type) == sizeof(double) ? DBL_MANT_DIG       \
 133                 : 0))
 134
 135 #define __type_float(_type)                                     \
 136         {                                                       \
 137           .atype = atype_float,                                 \
 138           .u =                                                  \
 139                 {                                               \
 140                   ._float =                                     \
 141                         {                                       \
 142                           .exp_dig = sizeof(_type) * CHAR_BIT   \
 143                                           - _float_mant_dig(_type), \
 144                           .mant_dig = _float_mant_dig(_type),   \
 145                           .alignment = lttng_alignof(_type) * CHAR_BIT, \
 146                           .reverse_byte_order = BYTE_ORDER != FLOAT_WORD_ORDER, \
 147                         }                                       \
 148                 }                                               \
 149         }                                                       \
 150
 151 #define LTTNG_UST_FLOAT_TYPE_PADDING    24
 152 struct lttng_float_type {
 153         unsigned int exp_dig;           /* exponent digits, in bits */
 154         unsigned int mant_dig;          /* mantissa digits, in bits */
 155         unsigned short alignment;       /* in bits */
 156         unsigned int reverse_byte_order:1;
 157         char padding[LTTNG_UST_FLOAT_TYPE_PADDING];
 158 };
 159
 160 #define LTTNG_UST_TYPE_PADDING  128
 161 struct lttng_type {
 162         enum lttng_abstract_types atype;
 163         union {
 164                 /* provider ABI 2.0 */
 165                 struct lttng_integer_type integer;
 166                 struct lttng_float_type _float;
 167                 struct {
 168                         enum lttng_string_encodings encoding;
 169                 } string;
 170                 struct {
 171                         const struct lttng_enum_desc *desc;     /* Enumeration mapping */
 172                         struct lttng_type *container_type;
 173                 } enum_nestable;
 174                 struct {
 175                         const struct lttng_type *elem_type;
 176                         unsigned int length;                    /* Num. elems. */
 177                         unsigned int alignment;
 178                 } array_nestable;
 179                 struct {
 180                         const char *length_name;                /* Length field name. */
 181                         const struct lttng_type *elem_type;
 182                         unsigned int alignment;                 /* Alignment before elements. */
 183                 } sequence_nestable;
 184                 struct {
 185                         unsigned int nr_fields;
 186                         const struct lttng_event_field *fields; /* Array of fields. */
 187                         unsigned int alignment;
 188                 } struct_nestable;
 189
 190                 char padding[LTTNG_UST_TYPE_PADDING];
 191         } u;
 192 };
 193
 194 #define LTTNG_UST_ENUM_TYPE_PADDING     24
 195 struct lttng_enum_desc {
 196         const char *name;
 197         const struct lttng_enum_entry *entries;
 198         unsigned int nr_entries;
 199         char padding[LTTNG_UST_ENUM_TYPE_PADDING];
 200 };
 201
 202 /*
 203  * Event field description
 204  *
 205  * IMPORTANT: this structure is part of the ABI between the probe and
 206  * UST. Fields need to be only added at the end, never reordered, never
 207  * removed.
 208  */
 209
 210 #define LTTNG_UST_EVENT_FIELD_PADDING   28
 211 struct lttng_event_field {
 212         const char *name;
 213         struct lttng_type type;
 214         unsigned int nowrite;   /* do not write into trace */
 215         union {
 216                 struct {
 217                         unsigned int nofilter:1;        /* do not consider for filter */
 218                 } ext;
 219                 char padding[LTTNG_UST_EVENT_FIELD_PADDING];
 220         } u;
 221 };
 222
 223 enum lttng_ust_dynamic_type {
 224         LTTNG_UST_DYNAMIC_TYPE_NONE,
 225         LTTNG_UST_DYNAMIC_TYPE_S8,
 226         LTTNG_UST_DYNAMIC_TYPE_S16,
 227         LTTNG_UST_DYNAMIC_TYPE_S32,
 228         LTTNG_UST_DYNAMIC_TYPE_S64,
 229         LTTNG_UST_DYNAMIC_TYPE_U8,
 230         LTTNG_UST_DYNAMIC_TYPE_U16,
 231         LTTNG_UST_DYNAMIC_TYPE_U32,
 232         LTTNG_UST_DYNAMIC_TYPE_U64,
 233         LTTNG_UST_DYNAMIC_TYPE_FLOAT,
 234         LTTNG_UST_DYNAMIC_TYPE_DOUBLE,
 235         LTTNG_UST_DYNAMIC_TYPE_STRING,
 236         _NR_LTTNG_UST_DYNAMIC_TYPES,
 237 };
 238
 239 struct lttng_ctx_value {
 240         enum lttng_ust_dynamic_type sel;
 241         union {
 242                 int64_t s64;
 243                 uint64_t u64;
 244                 const char *str;
 245                 double d;
 246         } u;
 247 };
 248
 249 struct lttng_perf_counter_field;
 250
 251 #define LTTNG_UST_CTX_FIELD_PADDING     40
 252 struct lttng_ctx_field {
 253         struct lttng_event_field event_field;
 254         size_t (*get_size)(struct lttng_ctx_field *field, size_t offset);
 255         void (*record)(struct lttng_ctx_field *field,
 256                        struct lttng_ust_lib_ring_buffer_ctx *ctx,
 257                        struct lttng_channel *chan);
 258         void (*get_value)(struct lttng_ctx_field *field,
 259                          struct lttng_ctx_value *value);
 260         union {
 261                 struct lttng_perf_counter_field *perf_counter;
 262                 char padding[LTTNG_UST_CTX_FIELD_PADDING];
 263         } u;
 264         void (*destroy)(struct lttng_ctx_field *field);
 265         char *field_name;       /* Has ownership, dynamically allocated. */
 266 };
 267
 268 #define LTTNG_UST_CTX_PADDING   20
 269 struct lttng_ctx {
 270         struct lttng_ctx_field *fields;
 271         unsigned int nr_fields;
 272         unsigned int allocated_fields;
 273         unsigned int largest_align;
 274         char padding[LTTNG_UST_CTX_PADDING];
 275 };
 276
 277 #define LTTNG_UST_EVENT_DESC_PADDING    40
 278 struct lttng_event_desc {
 279         const char *name;
 280         void (*probe_callback)(void);
 281         const struct lttng_event_ctx *ctx;      /* context */
 282         const struct lttng_event_field *fields; /* event payload */
 283         unsigned int nr_fields;
 284         const int **loglevel;
 285         const char *signature;  /* Argument types/names received */
 286         union {
 287                 struct {
 288                         const char **model_emf_uri;
 289                 } ext;
 290                 char padding[LTTNG_UST_EVENT_DESC_PADDING];
 291         } u;
 292 };
 293
 294 #define LTTNG_UST_PROBE_DESC_PADDING    12
 295 struct lttng_probe_desc {
 296         const char *provider;
 297         const struct lttng_event_desc **event_desc;
 298         unsigned int nr_events;
 299         struct cds_list_head head;              /* chain registered probes */
 300         struct cds_list_head lazy_init_head;
 301         int lazy;                               /* lazy registration */
 302         uint32_t major;
 303         uint32_t minor;
 304         char padding[LTTNG_UST_PROBE_DESC_PADDING];
 305 };
 306
 307 /* Data structures used by the tracer. */
 308
 309 /*
 310  * Bytecode interpreter return value masks.
 311  */
 312 enum lttng_bytecode_interpreter_ret {
 313         LTTNG_INTERPRETER_DISCARD = 0,
 314         LTTNG_INTERPRETER_RECORD_FLAG = (1ULL << 0),
 315         /* Other bits are kept for future use. */
 316 };
 317
 318 struct lttng_interpreter_output;
 319 struct lttng_ust_bytecode_runtime_private;
 320
 321 /*
 322  * This structure is used in the probes. More specifically, the
 323  * `interpreter_funcs` and `node` fields are explicity used in the
 324  * probes. When modifying this structure we must not change the layout
 325  * of these two fields as it is considered ABI.
 326  */
 327 struct lttng_bytecode_runtime {
 328         struct lttng_ust_bytecode_runtime_private *priv;
 329
 330         /* Associated bytecode */
 331         union {
 332                 uint64_t (*filter)(void *interpreter_data,
 333                                 const char *interpreter_stack_data);
 334                 uint64_t (*capture)(void *interpreter_data,
 335                                 const char *interpreter_stack_data,
 336                                 struct lttng_interpreter_output *interpreter_output);
 337         } interpreter_funcs;
 338         struct cds_list_head node;      /* list of bytecode runtime in event */
 339 };
 340
 341 /*
 342  * lttng_event structure is referred to by the tracing fast path. It
 343  * must be kept small.
 344  *
 345  * IMPORTANT: this structure is part of the ABI between the probe and
 346  * UST. Fields need to be only added at the end, never reordered, never
 347  * removed.
 348  */
 349
 350 struct lttng_ust_event_common_private;
 351
 352 enum lttng_ust_event_type {
 353         LTTNG_UST_EVENT_TYPE_RECORDER = 0,
 354         LTTNG_UST_EVENT_TYPE_NOTIFIER = 1,
 355 };
 356
 357 /*
 358  * struct lttng_ust_event_common is the common ancestor of the various
 359  * public event actions. Inheritance is done by composition: The parent
 360  * has a pointer to its child, and the child has a pointer to its
 361  * parent. Inheritance of those public structures is done by composition
 362  * to ensure both parent and child structures can be extended.
 363  *
 364  * The field @struct_size should be used to determine the size of the
 365  * structure. It should be queried before using additional fields added
 366  * at the end of the structure.
 367  */
 368 struct lttng_ust_event_common {
 369         uint32_t struct_size;                           /* Size of this structure. */
 370         struct lttng_ust_event_common_private *priv;    /* Private event interface */
 371
 372         enum lttng_ust_event_type type;
 373         void *child;                                    /* Pointer to child, for inheritance by aggregation. */
 374
 375         int enabled;
 376         int has_enablers_without_bytecode;
 377         /* list of struct lttng_bytecode_runtime, sorted by seqnum */
 378         struct cds_list_head filter_bytecode_runtime_head;
 379
 380         /* End of base ABI. Fields below should be used after checking struct_size. */
 381 };
 382
 383 struct lttng_ust_event_recorder_private;
 384
 385 /*
 386  * struct lttng_ust_event_recorder is the action for recording events
 387  * into a ring buffer. It inherits from struct lttng_ust_event_common
 388  * by composition to ensure both parent and child structure are
 389  * extensible.
 390  *
 391  * The field @struct_size should be used to determine the size of the
 392  * structure. It should be queried before using additional fields added
 393  * at the end of the structure.
 394  */
 395 struct lttng_ust_event_recorder {
 396         uint32_t struct_size;                           /* Size of this structure. */
 397         struct lttng_ust_event_common *parent;          /* Inheritance by aggregation. */
 398         struct lttng_ust_event_recorder_private *priv;  /* Private event record interface */
 399
 400         unsigned int id;
 401         struct lttng_channel *chan;
 402         struct lttng_ctx *ctx;
 403
 404         /* End of base ABI. Fields below should be used after checking struct_size. */
 405 };
 406
 407 struct lttng_ust_event_notifier_private;
 408
 409 /*
 410  * struct lttng_ust_event_notifier is the action for sending
 411  * notifications. It inherits from struct lttng_ust_event_common
 412  * by composition to ensure both parent and child structure are
 413  * extensible.
 414  *
 415  * The field @struct_size should be used to determine the size of the
 416  * structure. It should be queried before using additional fields added
 417  * at the end of the structure.
 418  */
 419 struct lttng_ust_event_notifier {
 420         uint32_t struct_size;                           /* Size of this structure. */
 421         struct lttng_ust_event_common *parent;          /* Inheritance by aggregation. */
 422         struct lttng_ust_event_notifier_private *priv;  /* Private event notifier interface */
 423
 424         void (*notification_send)(struct lttng_ust_event_notifier *event_notifier,
 425                 const char *stack_data);
 426         struct cds_list_head capture_bytecode_runtime_head;
 427
 428         /* End of base ABI. Fields below should be used after checking struct_size. */
 429 };
 430
 431 struct lttng_enum {
 432         const struct lttng_enum_desc *desc;
 433         struct lttng_session *session;
 434         struct cds_list_head node;      /* Enum list in session */
 435         struct cds_hlist_node hlist;    /* Session ht of enums */
 436         uint64_t id;                    /* Enumeration ID in sessiond */
 437 };
 438
 439 struct channel;
 440 struct lttng_ust_shm_handle;
 441
 442 /*
 443  * IMPORTANT: this structure is part of the ABI between the probe and
 444  * UST. Fields need to be only added at the end, never reordered, never
 445  * removed.
 446  */
 447 struct lttng_channel_ops {
 448         struct lttng_channel *(*channel_create)(const char *name,
 449                         void *buf_addr,
 450                         size_t subbuf_size, size_t num_subbuf,
 451                         unsigned int switch_timer_interval,
 452                         unsigned int read_timer_interval,
 453                         unsigned char *uuid,
 454                         uint32_t chan_id,
 455                         const int *stream_fds, int nr_stream_fds,
 456                         int64_t blocking_timeout);
 457         void (*channel_destroy)(struct lttng_channel *chan);
 458         int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 459                              uint32_t event_id);
 460         void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx);
 461         void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 462                         const void *src, size_t len);
 463         /*
 464          * packet_avail_size returns the available size in the current
 465          * packet. Note that the size returned is only a hint, since it
 466          * may change due to concurrent writes.
 467          */
 468         size_t (*packet_avail_size)(struct channel *chan,
 469                                     struct lttng_ust_shm_handle *handle);
 470         int (*is_finalized)(struct channel *chan);
 471         int (*is_disabled)(struct channel *chan);
 472         int (*flush_buffer)(struct channel *chan, struct lttng_ust_shm_handle *handle);
 473         void (*event_strcpy)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 474                         const char *src, size_t len);
 475 };
 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 struct lttng_channel {
 483         /*
 484          * The pointers located in this private data are NOT safe to be
 485          * dereferenced by the consumer. The only operations the
 486          * consumer process is designed to be allowed to do is to read
 487          * and perform subbuffer flush.
 488          */
 489         struct channel *chan;           /* Channel buffers */
 490         int enabled;
 491         struct lttng_ctx *ctx;
 492         /* Event ID management */
 493         struct lttng_session *session;
 494         int objd;                       /* Object associated to channel */
 495         struct cds_list_head node;      /* Channel list in session */
 496         const struct lttng_channel_ops *ops;
 497         int header_type;                /* 0: unset, 1: compact, 2: large */
 498         struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
 499
 500         /* Channel ID */
 501         unsigned int id;
 502         enum lttng_ust_abi_chan_type type;
 503         unsigned char uuid[LTTNG_UST_UUID_LEN]; /* Trace session unique ID */
 504         int tstate:1;                   /* Transient enable state */
 505 };
 506
 507 struct lttng_counter_dimension;
 508
 509 struct lttng_counter_ops {
 510         struct lib_counter *(*counter_create)(size_t nr_dimensions,
 511                         const struct lttng_counter_dimension *dimensions,
 512                         int64_t global_sum_step,
 513                         int global_counter_fd,
 514                         int nr_counter_cpu_fds,
 515                         const int *counter_cpu_fds,
 516                         bool is_daemon);
 517         void (*counter_destroy)(struct lib_counter *counter);
 518         int (*counter_add)(struct lib_counter *counter,
 519                         const size_t *dimension_indexes, int64_t v);
 520         int (*counter_read)(struct lib_counter *counter,
 521                         const size_t *dimension_indexes, int cpu,
 522                         int64_t *value, bool *overflow, bool *underflow);
 523         int (*counter_aggregate)(struct lib_counter *counter,
 524                         const size_t *dimension_indexes, int64_t *value,
 525                         bool *overflow, bool *underflow);
 526         int (*counter_clear)(struct lib_counter *counter, const size_t *dimension_indexes);
 527 };
 528
 529 #define LTTNG_UST_STACK_CTX_PADDING     32
 530 struct lttng_stack_ctx {
 531         struct lttng_ust_event_recorder *event_recorder;
 532         struct lttng_ctx *chan_ctx;     /* RCU dereferenced. */
 533         struct lttng_ctx *event_ctx;    /* RCU dereferenced. */
 534         char padding[LTTNG_UST_STACK_CTX_PADDING];
 535 };
 536
 537 #define LTTNG_UST_EVENT_HT_BITS         12
 538 #define LTTNG_UST_EVENT_HT_SIZE         (1U << LTTNG_UST_EVENT_HT_BITS)
 539
 540 struct lttng_ust_event_ht {
 541         struct cds_hlist_head table[LTTNG_UST_EVENT_HT_SIZE];
 542 };
 543
 544 #define LTTNG_UST_EVENT_NOTIFIER_HT_BITS                12
 545 #define LTTNG_UST_EVENT_NOTIFIER_HT_SIZE                (1U << LTTNG_UST_EVENT_NOTIFIER_HT_BITS)
 546 struct lttng_ust_event_notifier_ht {
 547         struct cds_hlist_head table[LTTNG_UST_EVENT_NOTIFIER_HT_SIZE];
 548 };
 549
 550 #define LTTNG_UST_ENUM_HT_BITS          12
 551 #define LTTNG_UST_ENUM_HT_SIZE          (1U << LTTNG_UST_ENUM_HT_BITS)
 552
 553 struct lttng_ust_enum_ht {
 554         struct cds_hlist_head table[LTTNG_UST_ENUM_HT_SIZE];
 555 };
 556
 557 struct lttng_ust_session_private;
 558
 559 /*
 560  * IMPORTANT: this structure is part of the ABI between the probe and
 561  * UST. Fields need to be only added at the end, never reordered, never
 562  * removed.
 563  */
 564 struct lttng_session {
 565         uint32_t struct_size;                   /* Size of this structure */
 566         struct lttng_ust_session_private *priv; /* Private session interface */
 567
 568         int active;                             /* Is trace session active ? */
 569 };
 570
 571 int lttng_probe_register(struct lttng_probe_desc *desc);
 572 void lttng_probe_unregister(struct lttng_probe_desc *desc);
 573
 574 /*
 575  * Can be used by applications that change their procname to clear the ust cached value.
 576  */
 577 void lttng_context_procname_reset(void);
 578
 579 struct lttng_transport *lttng_transport_find(const char *name);
 580
 581 int lttng_session_active(void);
 582
 583 void lttng_ust_dl_update(void *ip);
 584
 585 #ifdef __cplusplus
 586 }
 587 #endif
 588
 589 #endif /* _LTTNG_UST_EVENTS_H */