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