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