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;
  48 struct lttng_event_notifier_group;
  49
  50 /*
  51  * Data structures used by tracepoint event declarations, and by the
  52  * tracer. Those structures have padding for future extension.
  53  */
  54
  55 /* Type description */
  56
  57 /* Update the astract_types name table in lttng-types.c along with this enum */
  58 enum lttng_abstract_types {
  59         atype_integer,
  60         atype_enum,     /* legacy */
  61         atype_array,    /* legacy */
  62         atype_sequence, /* legacy */
  63         atype_string,
  64         atype_float,
  65         atype_dynamic,
  66         atype_struct,   /* legacy */
  67         atype_enum_nestable,
  68         atype_array_nestable,
  69         atype_sequence_nestable,
  70         atype_struct_nestable,
  71         NR_ABSTRACT_TYPES,
  72 };
  73
  74 /* Update the string_encodings name table in lttng-types.c along with this enum */
  75 enum lttng_string_encodings {
  76         lttng_encode_none = 0,
  77         lttng_encode_UTF8 = 1,
  78         lttng_encode_ASCII = 2,
  79         NR_STRING_ENCODINGS,
  80 };
  81
  82 struct lttng_enum_value {
  83         unsigned long long value;
  84         unsigned int signedness:1;
  85 };
  86
  87 enum lttng_enum_entry_options {
  88         LTTNG_ENUM_ENTRY_OPTION_IS_AUTO = 1U << 0,
  89 };
  90
  91 #define LTTNG_UST_ENUM_ENTRY_PADDING    16
  92 struct lttng_enum_entry {
  93         struct lttng_enum_value start, end; /* start and end are inclusive */
  94         const char *string;
  95         union {
  96                 struct {
  97                         unsigned int options;
  98                 } LTTNG_PACKED extra;
  99                 char padding[LTTNG_UST_ENUM_ENTRY_PADDING];
 100         } u;
 101 };
 102
 103 #define __type_integer(_type, _byte_order, _base, _encoding)    \
 104         {                                                       \
 105           .atype = atype_integer,                               \
 106           .u =                                                  \
 107                 {                                               \
 108                   .integer =                                    \
 109                         {                                       \
 110                           .size = sizeof(_type) * CHAR_BIT,     \
 111                           .alignment = lttng_alignof(_type) * CHAR_BIT, \
 112                           .signedness = lttng_is_signed_type(_type), \
 113                           .reverse_byte_order = _byte_order != BYTE_ORDER, \
 114                           .base = _base,                        \
 115                           .encoding = lttng_encode_##_encoding, \
 116                         }                                       \
 117                 },                                              \
 118         }                                                       \
 119
 120 #define LTTNG_UST_INTEGER_TYPE_PADDING  24
 121 struct lttng_integer_type {
 122         unsigned int size;              /* in bits */
 123         unsigned short alignment;       /* in bits */
 124         unsigned int signedness:1;
 125         unsigned int reverse_byte_order:1;
 126         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
 127         enum lttng_string_encodings encoding;
 128         char padding[LTTNG_UST_INTEGER_TYPE_PADDING];
 129 };
 130
 131 /*
 132  * Only float and double are supported. long double is not supported at
 133  * the moment.
 134  */
 135 #define _float_mant_dig(_type)                                          \
 136         (sizeof(_type) == sizeof(float) ? FLT_MANT_DIG                  \
 137                 : (sizeof(_type) == sizeof(double) ? DBL_MANT_DIG       \
 138                 : 0))
 139
 140 #define __type_float(_type)                                     \
 141         {                                                       \
 142           .atype = atype_float,                                 \
 143           .u =                                                  \
 144                 {                                               \
 145                   ._float =                                     \
 146                         {                                       \
 147                           .exp_dig = sizeof(_type) * CHAR_BIT   \
 148                                           - _float_mant_dig(_type), \
 149                           .mant_dig = _float_mant_dig(_type),   \
 150                           .alignment = lttng_alignof(_type) * CHAR_BIT, \
 151                           .reverse_byte_order = BYTE_ORDER != FLOAT_WORD_ORDER, \
 152                         }                                       \
 153                 }                                               \
 154         }                                                       \
 155
 156 #define LTTNG_UST_FLOAT_TYPE_PADDING    24
 157 struct lttng_float_type {
 158         unsigned int exp_dig;           /* exponent digits, in bits */
 159         unsigned int mant_dig;          /* mantissa digits, in bits */
 160         unsigned short alignment;       /* in bits */
 161         unsigned int reverse_byte_order:1;
 162         char padding[LTTNG_UST_FLOAT_TYPE_PADDING];
 163 };
 164
 165 /* legacy */
 166 #define LTTNG_UST_BASIC_TYPE_PADDING    128
 167 union _lttng_basic_type {
 168         struct lttng_integer_type integer;      /* legacy */
 169         struct {
 170                 const struct lttng_enum_desc *desc;     /* Enumeration mapping */
 171                 struct lttng_integer_type container_type;
 172         } enumeration;                          /* legacy */
 173         struct {
 174                 enum lttng_string_encodings encoding;
 175         } string;                               /* legacy */
 176         struct lttng_float_type _float;         /* legacy */
 177         char padding[LTTNG_UST_BASIC_TYPE_PADDING];
 178 };
 179
 180 /* legacy */
 181 struct lttng_basic_type {
 182         enum lttng_abstract_types atype;
 183         union {
 184                 union _lttng_basic_type basic;
 185         } u;
 186 };
 187
 188 #define LTTNG_UST_TYPE_PADDING  128
 189 struct lttng_type {
 190         enum lttng_abstract_types atype;
 191         union {
 192                 /* provider ABI 2.0 */
 193                 struct lttng_integer_type integer;
 194                 struct lttng_float_type _float;
 195                 struct {
 196                         enum lttng_string_encodings encoding;
 197                 } string;
 198                 struct {
 199                         const struct lttng_enum_desc *desc;     /* Enumeration mapping */
 200                         struct lttng_type *container_type;
 201                 } enum_nestable;
 202                 struct {
 203                         const struct lttng_type *elem_type;
 204                         unsigned int length;                    /* Num. elems. */
 205                         unsigned int alignment;
 206                 } array_nestable;
 207                 struct {
 208                         const char *length_name;                /* Length field name. */
 209                         const struct lttng_type *elem_type;
 210                         unsigned int alignment;                 /* Alignment before elements. */
 211                 } sequence_nestable;
 212                 struct {
 213                         unsigned int nr_fields;
 214                         const struct lttng_event_field *fields; /* Array of fields. */
 215                         unsigned int alignment;
 216                 } struct_nestable;
 217
 218                 union {
 219                         /* legacy provider ABI 1.0 */
 220                         union _lttng_basic_type basic;  /* legacy */
 221                         struct {
 222                                 struct lttng_basic_type elem_type;
 223                                 unsigned int length;            /* Num. elems. */
 224                         } array;                        /* legacy */
 225                         struct {
 226                                 struct lttng_basic_type length_type;
 227                                 struct lttng_basic_type elem_type;
 228                         } sequence;                     /* legacy */
 229                         struct {
 230                                 unsigned int nr_fields;
 231                                 struct lttng_event_field *fields;       /* Array of fields. */
 232                         } _struct;                      /* legacy */
 233                 } legacy;
 234                 char padding[LTTNG_UST_TYPE_PADDING];
 235         } u;
 236 };
 237
 238 #define LTTNG_UST_ENUM_TYPE_PADDING     24
 239 struct lttng_enum_desc {
 240         const char *name;
 241         const struct lttng_enum_entry *entries;
 242         unsigned int nr_entries;
 243         char padding[LTTNG_UST_ENUM_TYPE_PADDING];
 244 };
 245
 246 /*
 247  * Event field description
 248  *
 249  * IMPORTANT: this structure is part of the ABI between the probe and
 250  * UST. Fields need to be only added at the end, never reordered, never
 251  * removed.
 252  */
 253
 254 #define LTTNG_UST_EVENT_FIELD_PADDING   28
 255 struct lttng_event_field {
 256         const char *name;
 257         struct lttng_type type;
 258         unsigned int nowrite;   /* do not write into trace */
 259         union {
 260                 struct {
 261                         unsigned int nofilter:1;        /* do not consider for filter */
 262                 } ext;
 263                 char padding[LTTNG_UST_EVENT_FIELD_PADDING];
 264         } u;
 265 };
 266
 267 enum lttng_ust_dynamic_type {
 268         LTTNG_UST_DYNAMIC_TYPE_NONE,
 269         LTTNG_UST_DYNAMIC_TYPE_S8,
 270         LTTNG_UST_DYNAMIC_TYPE_S16,
 271         LTTNG_UST_DYNAMIC_TYPE_S32,
 272         LTTNG_UST_DYNAMIC_TYPE_S64,
 273         LTTNG_UST_DYNAMIC_TYPE_U8,
 274         LTTNG_UST_DYNAMIC_TYPE_U16,
 275         LTTNG_UST_DYNAMIC_TYPE_U32,
 276         LTTNG_UST_DYNAMIC_TYPE_U64,
 277         LTTNG_UST_DYNAMIC_TYPE_FLOAT,
 278         LTTNG_UST_DYNAMIC_TYPE_DOUBLE,
 279         LTTNG_UST_DYNAMIC_TYPE_STRING,
 280         _NR_LTTNG_UST_DYNAMIC_TYPES,
 281 };
 282
 283 struct lttng_ctx_value {
 284         enum lttng_ust_dynamic_type sel;
 285         union {
 286                 int64_t s64;
 287                 uint64_t u64;
 288                 const char *str;
 289                 double d;
 290         } u;
 291 };
 292
 293 struct lttng_perf_counter_field;
 294
 295 #define LTTNG_UST_CTX_FIELD_PADDING     40
 296 struct lttng_ctx_field {
 297         struct lttng_event_field event_field;
 298         size_t (*get_size)(struct lttng_ctx_field *field, size_t offset);
 299         void (*record)(struct lttng_ctx_field *field,
 300                        struct lttng_ust_lib_ring_buffer_ctx *ctx,
 301                        struct lttng_channel *chan);
 302         void (*get_value)(struct lttng_ctx_field *field,
 303                          struct lttng_ctx_value *value);
 304         union {
 305                 struct lttng_perf_counter_field *perf_counter;
 306                 char padding[LTTNG_UST_CTX_FIELD_PADDING];
 307         } u;
 308         void (*destroy)(struct lttng_ctx_field *field);
 309         char *field_name;       /* Has ownership, dynamically allocated. */
 310 };
 311
 312 #define LTTNG_UST_CTX_PADDING   20
 313 struct lttng_ctx {
 314         struct lttng_ctx_field *fields;
 315         unsigned int nr_fields;
 316         unsigned int allocated_fields;
 317         unsigned int largest_align;
 318         char padding[LTTNG_UST_CTX_PADDING];
 319 };
 320
 321 #define LTTNG_UST_EVENT_DESC_PADDING    40
 322 struct lttng_event_desc {
 323         const char *name;
 324         void (*probe_callback)(void);
 325         const struct lttng_event_ctx *ctx;      /* context */
 326         const struct lttng_event_field *fields; /* event payload */
 327         unsigned int nr_fields;
 328         const int **loglevel;
 329         const char *signature;  /* Argument types/names received */
 330         union {
 331                 struct {
 332                         const char **model_emf_uri;
 333                         void (*event_notifier_callback)(void);
 334                 } ext;
 335                 char padding[LTTNG_UST_EVENT_DESC_PADDING];
 336         } u;
 337 };
 338
 339 #define LTTNG_UST_PROBE_DESC_PADDING    12
 340 struct lttng_probe_desc {
 341         const char *provider;
 342         const struct lttng_event_desc **event_desc;
 343         unsigned int nr_events;
 344         struct cds_list_head head;              /* chain registered probes */
 345         struct cds_list_head lazy_init_head;
 346         int lazy;                               /* lazy registration */
 347         uint32_t major;
 348         uint32_t minor;
 349         char padding[LTTNG_UST_PROBE_DESC_PADDING];
 350 };
 351
 352 /* Data structures used by the tracer. */
 353
 354 /*
 355  * Bytecode interpreter return value masks.
 356  */
 357 enum lttng_bytecode_interpreter_ret {
 358         LTTNG_INTERPRETER_DISCARD = 0,
 359         LTTNG_INTERPRETER_RECORD_FLAG = (1ULL << 0),
 360         /* Other bits are kept for future use. */
 361 };
 362
 363 struct lttng_interpreter_output;
 364 struct lttng_ust_bytecode_runtime_private;
 365
 366 /*
 367  * This structure is used in the probes. More specifically, the
 368  * `interpreter_funcs` and `node` fields are explicity used in the
 369  * probes. When modifying this structure we must not change the layout
 370  * of these two fields as it is considered ABI.
 371  */
 372 struct lttng_bytecode_runtime {
 373         struct lttng_ust_bytecode_runtime_private *priv;
 374
 375         /* Associated bytecode */
 376         union {
 377                 uint64_t (*filter)(void *interpreter_data,
 378                                 const char *interpreter_stack_data);
 379                 uint64_t (*capture)(void *interpreter_data,
 380                                 const char *interpreter_stack_data,
 381                                 struct lttng_interpreter_output *interpreter_output);
 382         } interpreter_funcs;
 383         struct cds_list_head node;      /* list of bytecode runtime in event */
 384 };
 385
 386 /*
 387  * lttng_event structure is referred to by the tracing fast path. It
 388  * must be kept small.
 389  *
 390  * IMPORTANT: this structure is part of the ABI between the probe and
 391  * UST. Fields need to be only added at the end, never reordered, never
 392  * removed.
 393  */
 394
 395 struct lttng_ust_event_private;
 396
 397 struct lttng_event {
 398         uint32_t struct_size;                   /* Size of this structure. */
 399         struct lttng_ust_event_private *priv;   /* Private event interface */
 400
 401         unsigned int id;
 402         int enabled;
 403         int has_enablers_without_bytecode;
 404         /* list of struct lttng_bytecode_runtime, sorted by seqnum */
 405         struct cds_list_head filter_bytecode_runtime_head;
 406         struct lttng_channel *chan;
 407         struct lttng_ctx *ctx;
 408 };
 409
 410 struct lttng_event_notifier {
 411         uint64_t user_token;
 412         uint64_t error_counter_index;
 413         int enabled;
 414         int registered;                 /* has reg'd tracepoint probe */
 415         size_t num_captures;            /* Needed to allocate the msgpack array. */
 416         void (*notification_send)(struct lttng_event_notifier *event_notifier,
 417                 const char *stack_data);
 418         struct cds_list_head filter_bytecode_runtime_head;
 419         struct cds_list_head capture_bytecode_runtime_head;
 420         int has_enablers_without_bytecode;
 421         struct cds_list_head enablers_ref_head;
 422         const struct lttng_event_desc *desc;
 423         struct cds_hlist_node hlist;    /* hashtable of event_notifiers */
 424         struct cds_list_head node;      /* event_notifier list in session */
 425         struct lttng_event_notifier_group *group; /* weak ref */
 426 };
 427
 428 struct lttng_enum {
 429         const struct lttng_enum_desc *desc;
 430         struct lttng_session *session;
 431         struct cds_list_head node;      /* Enum list in session */
 432         struct cds_hlist_node hlist;    /* Session ht of enums */
 433         uint64_t id;                    /* Enumeration ID in sessiond */
 434 };
 435
 436 struct channel;
 437 struct lttng_ust_shm_handle;
 438
 439 /*
 440  * IMPORTANT: this structure is part of the ABI between the probe and
 441  * UST. Fields need to be only added at the end, never reordered, never
 442  * removed.
 443  */
 444 struct lttng_channel_ops {
 445         struct lttng_channel *(*channel_create)(const char *name,
 446                         void *buf_addr,
 447                         size_t subbuf_size, size_t num_subbuf,
 448                         unsigned int switch_timer_interval,
 449                         unsigned int read_timer_interval,
 450                         unsigned char *uuid,
 451                         uint32_t chan_id,
 452                         const int *stream_fds, int nr_stream_fds,
 453                         int64_t blocking_timeout);
 454         void (*channel_destroy)(struct lttng_channel *chan);
 455         int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 456                              uint32_t event_id);
 457         void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx);
 458         void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 459                         const void *src, size_t len);
 460         /*
 461          * packet_avail_size returns the available size in the current
 462          * packet. Note that the size returned is only a hint, since it
 463          * may change due to concurrent writes.
 464          */
 465         size_t (*packet_avail_size)(struct channel *chan,
 466                                     struct lttng_ust_shm_handle *handle);
 467         int (*is_finalized)(struct channel *chan);
 468         int (*is_disabled)(struct channel *chan);
 469         int (*flush_buffer)(struct channel *chan, struct lttng_ust_shm_handle *handle);
 470         void (*event_strcpy)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 471                         const char *src, size_t len);
 472 };
 473
 474 /*
 475  * IMPORTANT: this structure is part of the ABI between the probe and
 476  * UST. Fields need to be only added at the end, never reordered, never
 477  * removed.
 478  */
 479 struct lttng_channel {
 480         /*
 481          * The pointers located in this private data are NOT safe to be
 482          * dereferenced by the consumer. The only operations the
 483          * consumer process is designed to be allowed to do is to read
 484          * and perform subbuffer flush.
 485          */
 486         struct channel *chan;           /* Channel buffers */
 487         int enabled;
 488         struct lttng_ctx *ctx;
 489         /* Event ID management */
 490         struct lttng_session *session;
 491         int objd;                       /* Object associated to channel */
 492         struct cds_list_head node;      /* Channel list in session */
 493         const struct lttng_channel_ops *ops;
 494         int header_type;                /* 0: unset, 1: compact, 2: large */
 495         struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
 496
 497         /* Channel ID */
 498         unsigned int id;
 499         enum lttng_ust_chan_type type;
 500         unsigned char uuid[LTTNG_UST_UUID_LEN]; /* Trace session unique ID */
 501         int tstate:1;                   /* Transient enable state */
 502 };
 503
 504 struct lttng_counter_dimension;
 505
 506 struct lttng_counter_ops {
 507         struct lib_counter *(*counter_create)(size_t nr_dimensions,
 508                         const struct lttng_counter_dimension *dimensions,
 509                         int64_t global_sum_step,
 510                         int global_counter_fd,
 511                         int nr_counter_cpu_fds,
 512                         const int *counter_cpu_fds,
 513                         bool is_daemon);
 514         void (*counter_destroy)(struct lib_counter *counter);
 515         int (*counter_add)(struct lib_counter *counter,
 516                         const size_t *dimension_indexes, int64_t v);
 517         int (*counter_read)(struct lib_counter *counter,
 518                         const size_t *dimension_indexes, int cpu,
 519                         int64_t *value, bool *overflow, bool *underflow);
 520         int (*counter_aggregate)(struct lib_counter *counter,
 521                         const size_t *dimension_indexes, int64_t *value,
 522                         bool *overflow, bool *underflow);
 523         int (*counter_clear)(struct lib_counter *counter, const size_t *dimension_indexes);
 524 };
 525
 526 #define LTTNG_UST_STACK_CTX_PADDING     32
 527 struct lttng_stack_ctx {
 528         struct lttng_event *event;
 529         struct lttng_ctx *chan_ctx;     /* RCU dereferenced. */
 530         struct lttng_ctx *event_ctx;    /* RCU dereferenced. */
 531         char padding[LTTNG_UST_STACK_CTX_PADDING];
 532 };
 533
 534 #define LTTNG_UST_EVENT_HT_BITS         12
 535 #define LTTNG_UST_EVENT_HT_SIZE         (1U << LTTNG_UST_EVENT_HT_BITS)
 536
 537 struct lttng_ust_event_ht {
 538         struct cds_hlist_head table[LTTNG_UST_EVENT_HT_SIZE];
 539 };
 540
 541 #define LTTNG_UST_EVENT_NOTIFIER_HT_BITS                12
 542 #define LTTNG_UST_EVENT_NOTIFIER_HT_SIZE                (1U << LTTNG_UST_EVENT_NOTIFIER_HT_BITS)
 543 struct lttng_ust_event_notifier_ht {
 544         struct cds_hlist_head table[LTTNG_UST_EVENT_NOTIFIER_HT_SIZE];
 545 };
 546
 547 #define LTTNG_UST_ENUM_HT_BITS          12
 548 #define LTTNG_UST_ENUM_HT_SIZE          (1U << LTTNG_UST_ENUM_HT_BITS)
 549
 550 struct lttng_ust_enum_ht {
 551         struct cds_hlist_head table[LTTNG_UST_ENUM_HT_SIZE];
 552 };
 553
 554 struct lttng_ust_session_private;
 555
 556 /*
 557  * IMPORTANT: this structure is part of the ABI between the probe and
 558  * UST. Fields need to be only added at the end, never reordered, never
 559  * removed.
 560  */
 561 struct lttng_session {
 562         struct lttng_ust_session_private *priv; /* Private session interface */
 563
 564         int active;                             /* Is trace session active ? */
 565 };
 566
 567 int lttng_probe_register(struct lttng_probe_desc *desc);
 568 void lttng_probe_unregister(struct lttng_probe_desc *desc);
 569
 570 /*
 571  * Can be used by applications that change their procname to clear the ust cached value.
 572  */
 573 void lttng_context_procname_reset(void);
 574
 575 struct lttng_transport *lttng_transport_find(const char *name);
 576
 577 int lttng_session_active(void);
 578
 579 void lttng_ust_dl_update(void *ip);
 580
 581 #ifdef __cplusplus
 582 }
 583 #endif
 584
 585 #endif /* _LTTNG_UST_EVENTS_H */