include/lttng/events.h

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   2  *
   3  * lttng/events.h
   4  *
   5  * Holds LTTng per-session event registry.
   6  *
   7  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  */
   9
  10 #ifndef _LTTNG_EVENTS_H
  11 #define _LTTNG_EVENTS_H
  12
  13 #include <lttng/kernel-version.h>
  14 #include <linux/list.h>
  15 #include <linux/kprobes.h>
  16 #include <linux/kref.h>
  17 #include <linux/uuid.h>
  18 #include <linux/irq_work.h>
  19 #include <wrapper/uprobes.h>
  20 #include <lttng/cpuhotplug.h>
  21 #include <lttng/tracer.h>
  22 #include <lttng/abi.h>
  23 #include <lttng/abi-old.h>
  24 #include <lttng/endian.h>
  25
  26 #define lttng_is_signed_type(type)      (((type) -1) < (type) 1)
  27
  28 struct lttng_kernel_channel_buffer;
  29 struct lttng_kernel_session;
  30 struct lttng_kernel_ring_buffer_ctx;
  31
  32 /* Type description */
  33
  34 enum lttng_kernel_type {
  35         lttng_kernel_type_integer,
  36         lttng_kernel_type_string,
  37         lttng_kernel_type_enum,
  38         lttng_kernel_type_array,
  39         lttng_kernel_type_sequence,
  40         lttng_kernel_type_struct,
  41         lttng_kernel_type_variant,
  42         NR_LTTNG_KERNEL_TYPES,
  43 };
  44
  45 enum lttng_kernel_string_encoding {
  46         lttng_kernel_string_encoding_none = 0,
  47         lttng_kernel_string_encoding_UTF8 = 1,
  48         lttng_kernel_string_encoding_ASCII = 2,
  49         NR_LTTNG_KERNEL_STRING_ENCODING,
  50 };
  51
  52 struct lttng_kernel_enum_value {
  53         unsigned long long value;
  54         unsigned int signedness:1;
  55 };
  56
  57 struct lttng_kernel_enum_entry {
  58         struct lttng_kernel_enum_value start, end;      /* start and end are inclusive */
  59         const char *string;
  60         struct {
  61                 unsigned int is_auto:1;
  62         } options;
  63 };
  64
  65 /*
  66  * struct lttng_kernel_type_common is fixed-size. Its children inherits
  67  * from it by embedding struct lttng_kernel_type_common as its first field.
  68  */
  69 struct lttng_kernel_type_common {
  70         enum lttng_kernel_type type;
  71 };
  72
  73 struct lttng_kernel_type_integer {
  74         struct lttng_kernel_type_common parent;
  75         unsigned int size;              /* in bits */
  76         unsigned short alignment;       /* in bits */
  77         unsigned int signedness:1,
  78                 reverse_byte_order:1,
  79                 user:1;                 /* fetch from user-space */
  80         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
  81 };
  82
  83 struct lttng_kernel_type_string {
  84         struct lttng_kernel_type_common parent;
  85         enum lttng_kernel_string_encoding encoding;
  86         unsigned int user:1;            /* fetch from user-space */
  87 };
  88
  89 struct lttng_kernel_type_enum {
  90         struct lttng_kernel_type_common parent;
  91         const struct lttng_kernel_enum_desc *desc;      /* Enumeration mapping */
  92         const struct lttng_kernel_type_common *container_type;
  93 };
  94
  95 struct lttng_kernel_type_array {
  96         struct lttng_kernel_type_common parent;
  97         const struct lttng_kernel_type_common *elem_type;
  98         unsigned int length;                    /* Num. elems. */
  99         unsigned int alignment;         /* Alignment in bytes before elements. */
 100         enum lttng_kernel_string_encoding encoding;
 101 };
 102
 103 struct lttng_kernel_type_sequence {
 104         struct lttng_kernel_type_common parent;
 105         const char *length_name;        /* Length field name. If NULL, use previous field. */
 106         const struct lttng_kernel_type_common *elem_type;
 107         unsigned int alignment;         /* Alignment in bytes before elements. */
 108         enum lttng_kernel_string_encoding encoding;
 109 };
 110
 111 struct lttng_kernel_type_struct {
 112         struct lttng_kernel_type_common parent;
 113         unsigned int nr_fields;
 114         const struct lttng_kernel_event_field * const *fields;  /* Array of pointers to fields. */
 115         unsigned int alignment;         /* Alignment in bits */
 116 };
 117
 118 struct lttng_kernel_type_variant {
 119         struct lttng_kernel_type_common parent;
 120         const char *tag_name;           /* Tag field name. If NULL, use previous field. */
 121         const struct lttng_kernel_event_field * const *choices; /* Array of pointers to fields. */
 122         unsigned int nr_choices;
 123         unsigned int alignment;         /* Alignment in bytes */
 124 };
 125
 126 struct lttng_kernel_enum_desc {
 127         const char *name;
 128         const struct lttng_kernel_enum_entry * const *entries;
 129         unsigned int nr_entries;
 130         const struct lttng_kernel_probe_desc *probe_desc;
 131 };
 132
 133 /* Event field description */
 134
 135 struct lttng_kernel_event_field {
 136         const char *name;
 137         const struct lttng_kernel_type_common *type;
 138         unsigned int nowrite:1,         /* do not write into trace */
 139                         nofilter:1;     /* do not consider for filter */
 140 };
 141
 142 #ifndef PARAMS
 143 #define PARAMS(args...) args
 144 #endif
 145
 146 #define _lttng_kernel_static_type_integer(_size, _alignment, _signedness, _byte_order, _user, _base)    \
 147         ((const struct lttng_kernel_type_common *) __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_type_integer, { \
 148                 .parent = {                                                                             \
 149                         .type = lttng_kernel_type_integer,                                                      \
 150                 },                                                                                      \
 151                 .size = (_size),                                                                        \
 152                 .alignment = (_alignment),                                                              \
 153                 .signedness = (_signedness),                                                            \
 154                 .reverse_byte_order = (_byte_order) != __BYTE_ORDER,                                    \
 155                 .user = (_user),                                                                        \
 156                 .base = (_base),                                                                        \
 157         }))
 158
 159 #define lttng_kernel_static_type_integer(_size, _alignment, _signedness, _byte_order, _base)            \
 160         _lttng_kernel_static_type_integer(_size, _alignment, _signedness, _byte_order, 0, _base)
 161
 162 #define lttng_kernel_static_type_user_integer(_size, _alignment, _signedness, _byte_order, _base)       \
 163         _lttng_kernel_static_type_integer(_size, _alignment, _signedness, _byte_order, 1, _base)
 164
 165 #define _lttng_kernel_static_type_integer_from_type(_type, _byte_order, _user, _base)                   \
 166         lttng_kernel_static_type_integer(sizeof(_type) * CHAR_BIT,                                      \
 167                         lttng_alignof(_type) * CHAR_BIT,                                                \
 168                         lttng_is_signed_type(_type),                                                    \
 169                         _byte_order,                                                                    \
 170                         _base)
 171
 172 #define lttng_kernel_static_type_integer_from_type(_type, _byte_order, _base)                           \
 173         _lttng_kernel_static_type_integer_from_type(_type, _byte_order, 0, _base)
 174
 175 #define lttng_kernel_static_type_user_integer_from_type(_type, _byte_order, _base)                      \
 176         _lttng_kernel_static_type_integer_from_type(_type, _byte_order, 1, _base)
 177
 178 #define lttng_kernel_static_type_enum(_desc, _container_type)                                           \
 179         ((const struct lttng_kernel_type_common *) __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_type_enum, { \
 180                 .parent = {                                                                             \
 181                         .type = lttng_kernel_type_enum,                                                 \
 182                 },                                                                                      \
 183                 .desc = (_desc),                                                                        \
 184                 .container_type = (_container_type),                                                    \
 185         }))
 186
 187 #define lttng_kernel_static_type_array(_length, _elem_type, _alignment, _encoding)                      \
 188         ((const struct lttng_kernel_type_common *) __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_type_array, { \
 189                 .parent = {                                                                             \
 190                         .type = lttng_kernel_type_array,                                                \
 191                 },                                                                                      \
 192                 .length = (_length),                                                                    \
 193                 .alignment = (_alignment),                                                              \
 194                 .encoding = lttng_kernel_string_encoding_##_encoding,                                   \
 195                 .elem_type = (_elem_type),                                                              \
 196         }))
 197
 198 #define lttng_kernel_static_type_array_text(_length)                                                    \
 199         lttng_kernel_static_type_array(_length,                                                         \
 200                 lttng_kernel_static_type_integer(sizeof(char) * CHAR_BIT,                               \
 201                                 lttng_alignof(char) * CHAR_BIT, lttng_is_signed_type(char),             \
 202                                 __BYTE_ORDER, 10),                                                      \
 203                 0, UTF8)
 204
 205 #define lttng_kernel_static_type_sequence(_length_name, _elem_type, _alignment, _encoding)                      \
 206         ((const struct lttng_kernel_type_common *) __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_type_sequence, { \
 207                 .parent = {                                                                             \
 208                         .type = lttng_kernel_type_sequence,                                             \
 209                 },                                                                                      \
 210                 .length_name = (_length_name),                                                          \
 211                 .alignment = (_alignment),                                                              \
 212                 .encoding = lttng_kernel_string_encoding_##_encoding,                                   \
 213                 .elem_type = (_elem_type),                                                              \
 214         }))
 215
 216 #define lttng_kernel_static_type_string(_encoding, _user)                                               \
 217         ((const struct lttng_kernel_type_common *) __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_type_string, { \
 218                 .parent = {                                                                             \
 219                         .type = lttng_kernel_type_string,                                               \
 220                 },                                                                                      \
 221                 .encoding = lttng_kernel_string_encoding_##_encoding,                                   \
 222                 .user = (_user),                                                                        \
 223         }))
 224
 225 #define lttng_kernel_static_type_struct_init(_nr_fields, _fields, _alignment)                           \
 226         {                                                                                               \
 227                 .parent = {                                                                             \
 228                         .type = lttng_kernel_type_struct,                                               \
 229                 },                                                                                      \
 230                 .nr_fields = (_nr_fields),                                                              \
 231                 .fields = _fields,                                                                      \
 232                 .alignment = (_alignment),                                                              \
 233         }
 234
 235 #define lttng_kernel_static_type_struct(_nr_fields, _fields, _alignment)                                \
 236         ((const struct lttng_kernel_type_common *) __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_type_struct, \
 237                 lttng_kernel_static_type_struct_init(_nr_fields, PARAMS(_fields), _alignment)                   \
 238         ))
 239
 240 #define lttng_kernel_static_type_variant(_nr_choices, _choices, _tag_name, _alignment)                  \
 241         ((const struct lttng_kernel_type_common *) __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_type_variant, { \
 242                 .parent = {                                                                             \
 243                         .type = lttng_kernel_type_variant,                                              \
 244                 },                                                                                      \
 245                 .tag_name = (_tag_name),                                                                \
 246                 .choices = _choices,                                                                    \
 247                 .nr_choices = (_nr_choices),                                                            \
 248                 .alignment = (_alignment),                                                              \
 249         }))
 250
 251 #define lttng_kernel_static_event_field(_name, _type, _nowrite, _nofilter)                              \
 252         __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_event_field, {                               \
 253                 .name = (_name),                                                                        \
 254                 .type = (_type),                                                                        \
 255                 .nowrite = (_nowrite),                                                                  \
 256                 .nofilter = (_nofilter),                                                                \
 257         })
 258
 259 #define lttng_kernel_static_event_field_array(_fields...)                                               \
 260         __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_event_field *,                               \
 261                 _fields                                                                                 \
 262         )
 263
 264 #define lttng_kernel_static_enum_entry_value(_string, _value)                                           \
 265         __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_enum_entry, {                                \
 266                 .start = {                                                                              \
 267                         .signedness = lttng_is_signed_type(__typeof__(_value)),                         \
 268                         .value = lttng_is_signed_type(__typeof__(_value)) ?                             \
 269                                 (long long) (_value) : (_value),                                        \
 270                 },                                                                                      \
 271                 .end = {                                                                                \
 272                         .signedness = lttng_is_signed_type(__typeof__(_value)),                         \
 273                         .value = lttng_is_signed_type(__typeof__(_value)) ?                             \
 274                                 (long long) (_value) : (_value),                                        \
 275                 },                                                                                      \
 276                 .string = (_string),                                                                    \
 277         }),
 278
 279 #define lttng_kernel_static_enum_entry_range(_string, _range_start, _range_end)                         \
 280         __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_enum_entry, {                                \
 281                 .start = {                                                                              \
 282                         .signedness = lttng_is_signed_type(__typeof__(_range_start)),                   \
 283                         .value = lttng_is_signed_type(__typeof__(_range_start)) ?                       \
 284                                 (long long) (_range_start) : (_range_start),                            \
 285                 },                                                                                      \
 286                 .end = {                                                                                \
 287                         .signedness = lttng_is_signed_type(__typeof__(_range_end)),                     \
 288                         .value = lttng_is_signed_type(__typeof__(_range_end)) ?                         \
 289                                 (long long) (_range_end) : (_range_end),                                \
 290                 },                                                                                      \
 291                 .string = (_string),                                                                    \
 292         }),
 293
 294 #define lttng_kernel_static_enum_entry_auto(_string)                                                    \
 295         __LTTNG_COMPOUND_LITERAL(const struct lttng_kernel_enum_entry, {                                \
 296                 .start = {                                                                              \
 297                         .signedness = -1,                                                               \
 298                         .value = -1,                                                                    \
 299                 },                                                                                      \
 300                 .end = {                                                                                \
 301                         .signedness = -1,                                                               \
 302                         .value = -1,                                                                    \
 303                 },                                                                                      \
 304                 .string = (_string),                                                                    \
 305                 .options = {                                                                            \
 306                         .is_auto = 1,                                                                   \
 307                 }                                                                                       \
 308         }),
 309
 310 struct lttng_kernel_probe_ctx {
 311         struct lttng_kernel_event_common *event;
 312         uint8_t interruptible;
 313 };
 314
 315 struct lttng_kernel_tracepoint_class {
 316         void (*probe_callback)(void);
 317         const struct lttng_kernel_event_field * const *fields;  /* event payload */
 318         unsigned int nr_fields;
 319         const struct lttng_kernel_probe_desc *probe_desc;
 320 };
 321
 322 struct lttng_kernel_event_desc {
 323         const char *event_name;         /* lttng-modules name */
 324         const char *event_kname;        /* Linux kernel name (tracepoints) */
 325         const struct lttng_kernel_probe_desc *probe_desc;
 326         const struct lttng_kernel_tracepoint_class *tp_class;
 327         struct module *owner;
 328 };
 329
 330 struct lttng_kernel_probe_desc {
 331         const char *provider_name;
 332         const struct lttng_kernel_event_desc * const *event_desc;
 333         unsigned int nr_events;
 334         struct list_head head;                  /* chain registered probes */
 335         struct list_head lazy_init_head;
 336         int lazy;                               /* lazy registration */
 337 };
 338
 339 /*
 340  * Result of the run_filter() callback.
 341  */
 342 enum lttng_kernel_event_filter_result {
 343         LTTNG_KERNEL_EVENT_FILTER_ACCEPT = 0,
 344         LTTNG_KERNEL_EVENT_FILTER_REJECT = 1,
 345 };
 346
 347 struct lttng_kernel_event_common_private;
 348
 349 enum lttng_kernel_event_type {
 350         LTTNG_KERNEL_EVENT_TYPE_RECORDER = 0,
 351         LTTNG_KERNEL_EVENT_TYPE_NOTIFIER = 1,
 352 };
 353
 354 struct lttng_kernel_event_common {
 355         struct lttng_kernel_event_common_private *priv; /* Private event interface */
 356
 357         enum lttng_kernel_event_type type;
 358         /* Get child with container_of(). */
 359
 360         int enabled;
 361         int eval_filter;                                /* Need to evaluate filters */
 362         int (*run_filter)(const struct lttng_kernel_event_common *event,
 363                 const char *stack_data,
 364                 struct lttng_kernel_probe_ctx *probe_ctx,
 365                 void *filter_ctx);
 366 };
 367
 368 struct lttng_kernel_event_recorder_private;
 369
 370 struct lttng_kernel_event_recorder {
 371         struct lttng_kernel_event_common parent;
 372         struct lttng_kernel_event_recorder_private *priv;       /* Private event record interface */
 373
 374         struct lttng_kernel_channel_buffer *chan;
 375 };
 376
 377 struct lttng_kernel_notification_ctx {
 378         int eval_capture;                                       /* Capture evaluation available. */
 379 };
 380
 381 struct lttng_kernel_event_notifier_private;
 382
 383 struct lttng_kernel_event_notifier {
 384         struct lttng_kernel_event_common parent;
 385         struct lttng_kernel_event_notifier_private *priv;       /* Private event notifier interface */
 386
 387         int eval_capture;                               /* Need to evaluate capture */
 388         void (*notification_send)(struct lttng_kernel_event_notifier *event_notifier,
 389                 const char *stack_data,
 390                 struct lttng_kernel_probe_ctx *probe_ctx,
 391                 struct lttng_kernel_notification_ctx *notif_ctx);
 392 };
 393
 394 struct lttng_kernel_channel_buffer_ops {
 395         struct lttng_kernel_channel_buffer_ops_private *priv;   /* Private channel buffer ops interface. */
 396
 397         int (*event_reserve)(struct lttng_kernel_ring_buffer_ctx *ctx);
 398         void (*event_commit)(struct lttng_kernel_ring_buffer_ctx *ctx);
 399         void (*event_write)(struct lttng_kernel_ring_buffer_ctx *ctx, const void *src,
 400                             size_t len, size_t alignment);
 401         void (*event_write_from_user)(struct lttng_kernel_ring_buffer_ctx *ctx,
 402                                       const void *src, size_t len, size_t alignment);
 403         void (*event_memset)(struct lttng_kernel_ring_buffer_ctx *ctx,
 404                              int c, size_t len);
 405         void (*event_strcpy)(struct lttng_kernel_ring_buffer_ctx *ctx, const char *src,
 406                              size_t len);
 407         void (*event_strcpy_from_user)(struct lttng_kernel_ring_buffer_ctx *ctx,
 408                                        const char __user *src, size_t len);
 409         void (*event_pstrcpy_pad)(struct lttng_kernel_ring_buffer_ctx *ctx,
 410                                   const char *src, size_t len);
 411         void (*event_pstrcpy_pad_from_user)(struct lttng_kernel_ring_buffer_ctx *ctx,
 412                                   const char __user *src, size_t len);
 413         void (*lost_event_too_big)(struct lttng_kernel_channel_buffer *lttng_channel);
 414 };
 415
 416 enum lttng_kernel_channel_type {
 417         LTTNG_KERNEL_CHANNEL_TYPE_BUFFER = 0,
 418 };
 419
 420 struct lttng_kernel_channel_common_private;
 421
 422 /* Use container_of() to get child. */
 423 struct lttng_kernel_channel_common {
 424         struct lttng_kernel_channel_common_private *priv;       /* Private channel interface. */
 425
 426         enum lttng_kernel_channel_type type;
 427
 428         int enabled;
 429         struct lttng_kernel_session *session;
 430 };
 431
 432 struct lttng_kernel_channel_buffer_private;
 433
 434 struct lttng_kernel_channel_buffer {
 435         struct lttng_kernel_channel_common parent;
 436         struct lttng_kernel_channel_buffer_private *priv;
 437
 438         struct lttng_kernel_channel_buffer_ops *ops;
 439 };
 440
 441 #define LTTNG_DYNAMIC_LEN_STACK_SIZE    128
 442
 443 struct lttng_dynamic_len_stack {
 444         size_t stack[LTTNG_DYNAMIC_LEN_STACK_SIZE];
 445         size_t offset;
 446 };
 447
 448 DECLARE_PER_CPU(struct lttng_dynamic_len_stack, lttng_dynamic_len_stack);
 449
 450 /*
 451  * struct lttng_kernel_id_tracker declared in header due to deferencing of *v
 452  * in RCU_INITIALIZER(v).
 453  */
 454 #define LTTNG_ID_HASH_BITS      6
 455 #define LTTNG_ID_TABLE_SIZE     (1 << LTTNG_ID_HASH_BITS)
 456
 457 struct lttng_kernel_id_tracker_rcu {
 458         struct hlist_head id_hash[LTTNG_ID_TABLE_SIZE];
 459 };
 460
 461 struct lttng_kernel_id_tracker {
 462         struct lttng_kernel_id_tracker_private *priv;   /* Private API */
 463
 464         struct lttng_kernel_id_tracker_rcu *p;  /* RCU dereferenced. */
 465 };
 466
 467 struct lttng_kernel_session_private;
 468
 469 struct lttng_kernel_session {
 470         struct lttng_kernel_session_private *priv;      /* Private session interface */
 471
 472         int active;                     /* Is trace session active ? */
 473
 474         struct lttng_kernel_id_tracker pid_tracker;
 475         struct lttng_kernel_id_tracker vpid_tracker;
 476         struct lttng_kernel_id_tracker uid_tracker;
 477         struct lttng_kernel_id_tracker vuid_tracker;
 478         struct lttng_kernel_id_tracker gid_tracker;
 479         struct lttng_kernel_id_tracker vgid_tracker;
 480 };
 481
 482 int lttng_kernel_probe_register(struct lttng_kernel_probe_desc *desc);
 483 void lttng_kernel_probe_unregister(struct lttng_kernel_probe_desc *desc);
 484
 485 bool lttng_id_tracker_lookup(struct lttng_kernel_id_tracker_rcu *p, int id);
 486
 487 #endif /* _LTTNG_EVENTS_H */