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