lttng-events.h

   1 #ifndef _LTTNG_EVENTS_H
   2 #define _LTTNG_EVENTS_H
   3
   4 /*
   5  * lttng-events.h
   6  *
   7  * Holds LTTng per-session event registry.
   8  *
   9  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  *
  11  * This library is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU Lesser General Public
  13  * License as published by the Free Software Foundation; only
  14  * version 2.1 of the License.
  15  *
  16  * This library is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19  * Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public
  22  * License along with this library; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  24  */
  25
  26 #include <linux/version.h>
  27 #include <linux/list.h>
  28 #include <linux/kprobes.h>
  29 #include <linux/kref.h>
  30 #include "wrapper/uuid.h"
  31 #include "lttng-abi.h"
  32 #include "lttng-abi-old.h"
  33
  34 #define lttng_is_signed_type(type)      (((type)(-1)) < 0)
  35
  36 struct lttng_channel;
  37 struct lttng_session;
  38 struct lttng_metadata_cache;
  39 struct lib_ring_buffer_ctx;
  40 struct perf_event;
  41 struct perf_event_attr;
  42 struct lib_ring_buffer_config;
  43
  44 /* Type description */
  45
  46 /* Update the astract_types name table in lttng-types.c along with this enum */
  47 enum abstract_types {
  48         atype_integer,
  49         atype_enum,
  50         atype_array,
  51         atype_sequence,
  52         atype_string,
  53         NR_ABSTRACT_TYPES,
  54 };
  55
  56 /* Update the string_encodings name table in lttng-types.c along with this enum */
  57 enum lttng_string_encodings {
  58         lttng_encode_none = 0,
  59         lttng_encode_UTF8 = 1,
  60         lttng_encode_ASCII = 2,
  61         NR_STRING_ENCODINGS,
  62 };
  63
  64 enum channel_type {
  65         PER_CPU_CHANNEL,
  66         METADATA_CHANNEL,
  67 };
  68
  69 struct lttng_enum_entry {
  70         unsigned long long start, end;  /* start and end are inclusive */
  71         const char *string;
  72 };
  73
  74 #define __type_integer(_type, _byte_order, _base, _encoding)    \
  75         {                                                       \
  76             .atype = atype_integer,                             \
  77             .u.basic.integer =                                  \
  78                 {                                               \
  79                   .size = sizeof(_type) * CHAR_BIT,             \
  80                   .alignment = lttng_alignof(_type) * CHAR_BIT, \
  81                   .signedness = lttng_is_signed_type(_type),    \
  82                   .reverse_byte_order = _byte_order != __BYTE_ORDER,    \
  83                   .base = _base,                                \
  84                   .encoding = lttng_encode_##_encoding,         \
  85                 },                                              \
  86         }                                                       \
  87
  88 struct lttng_integer_type {
  89         unsigned int size;              /* in bits */
  90         unsigned short alignment;       /* in bits */
  91         unsigned int signedness:1,
  92                 reverse_byte_order:1;
  93         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
  94         enum lttng_string_encodings encoding;
  95 };
  96
  97 union _lttng_basic_type {
  98         struct lttng_integer_type integer;
  99         struct {
 100                 const char *name;
 101         } enumeration;
 102         struct {
 103                 enum lttng_string_encodings encoding;
 104         } string;
 105 };
 106
 107 struct lttng_basic_type {
 108         enum abstract_types atype;
 109         union {
 110                 union _lttng_basic_type basic;
 111         } u;
 112 };
 113
 114 struct lttng_type {
 115         enum abstract_types atype;
 116         union {
 117                 union _lttng_basic_type basic;
 118                 struct {
 119                         struct lttng_basic_type elem_type;
 120                         unsigned int length;            /* num. elems. */
 121                 } array;
 122                 struct {
 123                         struct lttng_basic_type length_type;
 124                         struct lttng_basic_type elem_type;
 125                 } sequence;
 126         } u;
 127 };
 128
 129 struct lttng_enum {
 130         const char *name;
 131         struct lttng_type container_type;
 132         const struct lttng_enum_entry *entries;
 133         unsigned int len;
 134 };
 135
 136 /* Event field description */
 137
 138 struct lttng_event_field {
 139         const char *name;
 140         struct lttng_type type;
 141 };
 142
 143 /*
 144  * We need to keep this perf counter field separately from struct
 145  * lttng_ctx_field because cpu hotplug needs fixed-location addresses.
 146  */
 147 struct lttng_perf_counter_field {
 148         struct notifier_block nb;
 149         int hp_enable;
 150         struct perf_event_attr *attr;
 151         struct perf_event **e;  /* per-cpu array */
 152 };
 153
 154 struct lttng_ctx_field {
 155         struct lttng_event_field event_field;
 156         size_t (*get_size)(size_t offset);
 157         void (*record)(struct lttng_ctx_field *field,
 158                        struct lib_ring_buffer_ctx *ctx,
 159                        struct lttng_channel *chan);
 160         union {
 161                 struct lttng_perf_counter_field *perf_counter;
 162         } u;
 163         void (*destroy)(struct lttng_ctx_field *field);
 164 };
 165
 166 struct lttng_ctx {
 167         struct lttng_ctx_field *fields;
 168         unsigned int nr_fields;
 169         unsigned int allocated_fields;
 170 };
 171
 172 struct lttng_event_desc {
 173         const char *name;
 174         void *probe_callback;
 175         const struct lttng_event_ctx *ctx;      /* context */
 176         const struct lttng_event_field *fields; /* event payload */
 177         unsigned int nr_fields;
 178         struct module *owner;
 179 };
 180
 181 struct lttng_probe_desc {
 182         const struct lttng_event_desc **event_desc;
 183         unsigned int nr_events;
 184         struct list_head head;                  /* chain registered probes */
 185 };
 186
 187 struct lttng_krp;                               /* Kretprobe handling */
 188
 189 /*
 190  * lttng_event structure is referred to by the tracing fast path. It must be
 191  * kept small.
 192  */
 193 struct lttng_event {
 194         unsigned int id;
 195         struct lttng_channel *chan;
 196         int enabled;
 197         const struct lttng_event_desc *desc;
 198         void *filter;
 199         struct lttng_ctx *ctx;
 200         enum lttng_kernel_instrumentation instrumentation;
 201         union {
 202                 struct {
 203                         struct kprobe kp;
 204                         char *symbol_name;
 205                 } kprobe;
 206                 struct {
 207                         struct lttng_krp *lttng_krp;
 208                         char *symbol_name;
 209                 } kretprobe;
 210                 struct {
 211                         char *symbol_name;
 212                 } ftrace;
 213         } u;
 214         struct list_head list;          /* Event list */
 215         unsigned int metadata_dumped:1;
 216 };
 217
 218 struct lttng_channel_ops {
 219         struct channel *(*channel_create)(const char *name,
 220                                 struct lttng_channel *lttng_chan,
 221                                 void *buf_addr,
 222                                 size_t subbuf_size, size_t num_subbuf,
 223                                 unsigned int switch_timer_interval,
 224                                 unsigned int read_timer_interval);
 225         void (*channel_destroy)(struct channel *chan);
 226         struct lib_ring_buffer *(*buffer_read_open)(struct channel *chan);
 227         int (*buffer_has_read_closed_stream)(struct channel *chan);
 228         void (*buffer_read_close)(struct lib_ring_buffer *buf);
 229         int (*event_reserve)(struct lib_ring_buffer_ctx *ctx,
 230                              uint32_t event_id);
 231         void (*event_commit)(struct lib_ring_buffer_ctx *ctx);
 232         void (*event_write)(struct lib_ring_buffer_ctx *ctx, const void *src,
 233                             size_t len);
 234         void (*event_write_from_user)(struct lib_ring_buffer_ctx *ctx,
 235                                       const void *src, size_t len);
 236         void (*event_memset)(struct lib_ring_buffer_ctx *ctx,
 237                              int c, size_t len);
 238         /*
 239          * packet_avail_size returns the available size in the current
 240          * packet. Note that the size returned is only a hint, since it
 241          * may change due to concurrent writes.
 242          */
 243         size_t (*packet_avail_size)(struct channel *chan);
 244         wait_queue_head_t *(*get_writer_buf_wait_queue)(struct channel *chan, int cpu);
 245         wait_queue_head_t *(*get_hp_wait_queue)(struct channel *chan);
 246         int (*is_finalized)(struct channel *chan);
 247         int (*is_disabled)(struct channel *chan);
 248         int (*timestamp_begin) (const struct lib_ring_buffer_config *config,
 249                         struct lib_ring_buffer *bufb,
 250                         uint64_t *timestamp_begin);
 251         int (*timestamp_end) (const struct lib_ring_buffer_config *config,
 252                         struct lib_ring_buffer *bufb,
 253                         uint64_t *timestamp_end);
 254         int (*events_discarded) (const struct lib_ring_buffer_config *config,
 255                         struct lib_ring_buffer *bufb,
 256                         uint64_t *events_discarded);
 257         int (*content_size) (const struct lib_ring_buffer_config *config,
 258                         struct lib_ring_buffer *bufb,
 259                         uint64_t *content_size);
 260         int (*packet_size) (const struct lib_ring_buffer_config *config,
 261                         struct lib_ring_buffer *bufb,
 262                         uint64_t *packet_size);
 263         int (*stream_id) (const struct lib_ring_buffer_config *config,
 264                         struct lib_ring_buffer *bufb,
 265                         uint64_t *stream_id);
 266         int (*current_timestamp) (const struct lib_ring_buffer_config *config,
 267                         struct lib_ring_buffer *bufb,
 268                         uint64_t *ts);
 269 };
 270
 271 struct lttng_transport {
 272         char *name;
 273         struct module *owner;
 274         struct list_head node;
 275         struct lttng_channel_ops ops;
 276 };
 277
 278 struct lttng_channel {
 279         unsigned int id;
 280         struct channel *chan;           /* Channel buffers */
 281         int enabled;
 282         struct lttng_ctx *ctx;
 283         /* Event ID management */
 284         struct lttng_session *session;
 285         struct file *file;              /* File associated to channel */
 286         unsigned int free_event_id;     /* Next event ID to allocate */
 287         struct list_head list;          /* Channel list */
 288         struct lttng_channel_ops *ops;
 289         struct lttng_transport *transport;
 290         struct lttng_event **sc_table;  /* for syscall tracing */
 291         struct lttng_event **compat_sc_table;
 292         struct lttng_event *sc_unknown; /* for unknown syscalls */
 293         struct lttng_event *sc_compat_unknown;
 294         struct lttng_event *sc_exit;    /* for syscall exit */
 295         int header_type;                /* 0: unset, 1: compact, 2: large */
 296         enum channel_type channel_type;
 297         unsigned int metadata_dumped:1;
 298 };
 299
 300 struct lttng_metadata_stream {
 301         void *priv;                     /* Ring buffer private data */
 302         struct lttng_metadata_cache *metadata_cache;
 303         unsigned int metadata_in;       /* Bytes read from the cache */
 304         unsigned int metadata_out;      /* Bytes consumed from stream */
 305         int finalized;                  /* Has channel been finalized */
 306         wait_queue_head_t read_wait;    /* Reader buffer-level wait queue */
 307         struct list_head list;          /* Stream list */
 308         struct lttng_transport *transport;
 309 };
 310
 311 struct lttng_session {
 312         int active;                     /* Is trace session active ? */
 313         int been_active;                /* Has trace session been active ? */
 314         struct file *file;              /* File associated to session */
 315         struct list_head chan;          /* Channel list head */
 316         struct list_head events;        /* Event list head */
 317         struct list_head list;          /* Session list */
 318         unsigned int free_chan_id;      /* Next chan ID to allocate */
 319         uuid_le uuid;                   /* Trace session unique ID */
 320         struct lttng_metadata_cache *metadata_cache;
 321         unsigned int metadata_dumped:1;
 322 };
 323
 324 struct lttng_metadata_cache {
 325         char *data;                     /* Metadata cache */
 326         unsigned int cache_alloc;       /* Metadata allocated size (bytes) */
 327         unsigned int metadata_written;  /* Number of bytes written in metadata cache */
 328         struct kref refcount;           /* Metadata cache usage */
 329         struct list_head metadata_stream;       /* Metadata stream list */
 330 };
 331
 332 struct lttng_session *lttng_session_create(void);
 333 int lttng_session_enable(struct lttng_session *session);
 334 int lttng_session_disable(struct lttng_session *session);
 335 void lttng_session_destroy(struct lttng_session *session);
 336 void metadata_cache_destroy(struct kref *kref);
 337
 338 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
 339                                        const char *transport_name,
 340                                        void *buf_addr,
 341                                        size_t subbuf_size, size_t num_subbuf,
 342                                        unsigned int switch_timer_interval,
 343                                        unsigned int read_timer_interval,
 344                                        enum channel_type channel_type);
 345 struct lttng_channel *lttng_global_channel_create(struct lttng_session *session,
 346                                        int overwrite, void *buf_addr,
 347                                        size_t subbuf_size, size_t num_subbuf,
 348                                        unsigned int switch_timer_interval,
 349                                        unsigned int read_timer_interval);
 350
 351 void lttng_metadata_channel_destroy(struct lttng_channel *chan);
 352 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 353                                    struct lttng_kernel_event *event_param,
 354                                    void *filter,
 355                                    const struct lttng_event_desc *internal_desc);
 356 struct lttng_event *lttng_event_compat_old_create(struct lttng_channel *chan,
 357                 struct lttng_kernel_old_event *old_event_param,
 358                 void *filter,
 359                 const struct lttng_event_desc *internal_desc);
 360
 361 int lttng_channel_enable(struct lttng_channel *channel);
 362 int lttng_channel_disable(struct lttng_channel *channel);
 363 int lttng_event_enable(struct lttng_event *event);
 364 int lttng_event_disable(struct lttng_event *event);
 365
 366 void lttng_transport_register(struct lttng_transport *transport);
 367 void lttng_transport_unregister(struct lttng_transport *transport);
 368
 369 void synchronize_trace(void);
 370 int lttng_abi_init(void);
 371 int lttng_abi_compat_old_init(void);
 372 void lttng_abi_exit(void);
 373 void lttng_abi_compat_old_exit(void);
 374
 375 int lttng_probe_register(struct lttng_probe_desc *desc);
 376 void lttng_probe_unregister(struct lttng_probe_desc *desc);
 377 const struct lttng_event_desc *lttng_event_get(const char *name);
 378 void lttng_event_put(const struct lttng_event_desc *desc);
 379 int lttng_probes_init(void);
 380 void lttng_probes_exit(void);
 381
 382 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
 383                 struct channel *chan);
 384
 385 #if defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS)
 386 int lttng_syscalls_register(struct lttng_channel *chan, void *filter);
 387 int lttng_syscalls_unregister(struct lttng_channel *chan);
 388 #else
 389 static inline int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
 390 {
 391         return -ENOSYS;
 392 }
 393
 394 static inline int lttng_syscalls_unregister(struct lttng_channel *chan)
 395 {
 396         return 0;
 397 }
 398 #endif
 399
 400 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx);
 401 int lttng_find_context(struct lttng_ctx *ctx, const char *name);
 402 void lttng_remove_context_field(struct lttng_ctx **ctx,
 403                                 struct lttng_ctx_field *field);
 404 void lttng_destroy_context(struct lttng_ctx *ctx);
 405 int lttng_add_pid_to_ctx(struct lttng_ctx **ctx);
 406 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
 407 int lttng_add_prio_to_ctx(struct lttng_ctx **ctx);
 408 int lttng_add_nice_to_ctx(struct lttng_ctx **ctx);
 409 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
 410 int lttng_add_tid_to_ctx(struct lttng_ctx **ctx);
 411 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
 412 int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx);
 413 int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx);
 414 int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx);
 415 #if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33))
 416 int lttng_add_perf_counter_to_ctx(uint32_t type,
 417                                   uint64_t config,
 418                                   const char *name,
 419                                   struct lttng_ctx **ctx);
 420 #else
 421 static inline
 422 int lttng_add_perf_counter_to_ctx(uint32_t type,
 423                                   uint64_t config,
 424                                   const char *name,
 425                                   struct lttng_ctx **ctx)
 426 {
 427         return -ENOSYS;
 428 }
 429 #endif
 430
 431 extern int lttng_statedump_start(struct lttng_session *session);
 432
 433 #ifdef CONFIG_KPROBES
 434 int lttng_kprobes_register(const char *name,
 435                 const char *symbol_name,
 436                 uint64_t offset,
 437                 uint64_t addr,
 438                 struct lttng_event *event);
 439 void lttng_kprobes_unregister(struct lttng_event *event);
 440 void lttng_kprobes_destroy_private(struct lttng_event *event);
 441 #else
 442 static inline
 443 int lttng_kprobes_register(const char *name,
 444                 const char *symbol_name,
 445                 uint64_t offset,
 446                 uint64_t addr,
 447                 struct lttng_event *event)
 448 {
 449         return -ENOSYS;
 450 }
 451
 452 static inline
 453 void lttng_kprobes_unregister(struct lttng_event *event)
 454 {
 455 }
 456
 457 static inline
 458 void lttng_kprobes_destroy_private(struct lttng_event *event)
 459 {
 460 }
 461 #endif
 462
 463 #ifdef CONFIG_KRETPROBES
 464 int lttng_kretprobes_register(const char *name,
 465                 const char *symbol_name,
 466                 uint64_t offset,
 467                 uint64_t addr,
 468                 struct lttng_event *event_entry,
 469                 struct lttng_event *event_exit);
 470 void lttng_kretprobes_unregister(struct lttng_event *event);
 471 void lttng_kretprobes_destroy_private(struct lttng_event *event);
 472 #else
 473 static inline
 474 int lttng_kretprobes_register(const char *name,
 475                 const char *symbol_name,
 476                 uint64_t offset,
 477                 uint64_t addr,
 478                 struct lttng_event *event_entry,
 479                 struct lttng_event *event_exit)
 480 {
 481         return -ENOSYS;
 482 }
 483
 484 static inline
 485 void lttng_kretprobes_unregister(struct lttng_event *event)
 486 {
 487 }
 488
 489 static inline
 490 void lttng_kretprobes_destroy_private(struct lttng_event *event)
 491 {
 492 }
 493 #endif
 494
 495 #ifdef CONFIG_DYNAMIC_FTRACE
 496 int lttng_ftrace_register(const char *name,
 497                           const char *symbol_name,
 498                           struct lttng_event *event);
 499 void lttng_ftrace_unregister(struct lttng_event *event);
 500 void lttng_ftrace_destroy_private(struct lttng_event *event);
 501 #else
 502 static inline
 503 int lttng_ftrace_register(const char *name,
 504                           const char *symbol_name,
 505                           struct lttng_event *event)
 506 {
 507         return -ENOSYS;
 508 }
 509
 510 static inline
 511 void lttng_ftrace_unregister(struct lttng_event *event)
 512 {
 513 }
 514
 515 static inline
 516 void lttng_ftrace_destroy_private(struct lttng_event *event)
 517 {
 518 }
 519 #endif
 520
 521 int lttng_calibrate(struct lttng_kernel_calibrate *calibrate);
 522
 523 extern const struct file_operations lttng_tracepoint_list_fops;
 524
 525 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35))
 526 #define TRACEPOINT_HAS_DATA_ARG
 527 #endif
 528
 529 #endif /* _LTTNG_EVENTS_H */