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;               /* lttng-modules name */
 174         const char *kname;              /* Linux kernel name (tracepoints) */
 175         void *probe_callback;
 176         const struct lttng_event_ctx *ctx;      /* context */
 177         const struct lttng_event_field *fields; /* event payload */
 178         unsigned int nr_fields;
 179         struct module *owner;
 180 };
 181
 182 struct lttng_probe_desc {
 183         const struct lttng_event_desc **event_desc;
 184         unsigned int nr_events;
 185         struct list_head head;                  /* chain registered probes */
 186 };
 187
 188 struct lttng_krp;                               /* Kretprobe handling */
 189
 190 /*
 191  * lttng_event structure is referred to by the tracing fast path. It must be
 192  * kept small.
 193  */
 194 struct lttng_event {
 195         unsigned int id;
 196         struct lttng_channel *chan;
 197         int enabled;
 198         const struct lttng_event_desc *desc;
 199         void *filter;
 200         struct lttng_ctx *ctx;
 201         enum lttng_kernel_instrumentation instrumentation;
 202         union {
 203                 struct {
 204                         struct kprobe kp;
 205                         char *symbol_name;
 206                 } kprobe;
 207                 struct {
 208                         struct lttng_krp *lttng_krp;
 209                         char *symbol_name;
 210                 } kretprobe;
 211                 struct {
 212                         char *symbol_name;
 213                 } ftrace;
 214         } u;
 215         struct list_head list;          /* Event list */
 216         unsigned int metadata_dumped:1;
 217 };
 218
 219 struct lttng_channel_ops {
 220         struct channel *(*channel_create)(const char *name,
 221                                 struct lttng_channel *lttng_chan,
 222                                 void *buf_addr,
 223                                 size_t subbuf_size, size_t num_subbuf,
 224                                 unsigned int switch_timer_interval,
 225                                 unsigned int read_timer_interval);
 226         void (*channel_destroy)(struct channel *chan);
 227         struct lib_ring_buffer *(*buffer_read_open)(struct channel *chan);
 228         int (*buffer_has_read_closed_stream)(struct channel *chan);
 229         void (*buffer_read_close)(struct lib_ring_buffer *buf);
 230         int (*event_reserve)(struct lib_ring_buffer_ctx *ctx,
 231                              uint32_t event_id);
 232         void (*event_commit)(struct lib_ring_buffer_ctx *ctx);
 233         void (*event_write)(struct lib_ring_buffer_ctx *ctx, const void *src,
 234                             size_t len);
 235         void (*event_write_from_user)(struct lib_ring_buffer_ctx *ctx,
 236                                       const void *src, size_t len);
 237         void (*event_memset)(struct lib_ring_buffer_ctx *ctx,
 238                              int c, size_t len);
 239         void (*event_strcpy)(struct lib_ring_buffer_ctx *ctx, const char *src,
 240                              size_t len);
 241         void (*event_strcpy_from_user)(struct lib_ring_buffer_ctx *ctx,
 242                                        const char __user *src, size_t len);
 243         /*
 244          * packet_avail_size returns the available size in the current
 245          * packet. Note that the size returned is only a hint, since it
 246          * may change due to concurrent writes.
 247          */
 248         size_t (*packet_avail_size)(struct channel *chan);
 249         wait_queue_head_t *(*get_writer_buf_wait_queue)(struct channel *chan, int cpu);
 250         wait_queue_head_t *(*get_hp_wait_queue)(struct channel *chan);
 251         int (*is_finalized)(struct channel *chan);
 252         int (*is_disabled)(struct channel *chan);
 253         int (*timestamp_begin) (const struct lib_ring_buffer_config *config,
 254                         struct lib_ring_buffer *bufb,
 255                         uint64_t *timestamp_begin);
 256         int (*timestamp_end) (const struct lib_ring_buffer_config *config,
 257                         struct lib_ring_buffer *bufb,
 258                         uint64_t *timestamp_end);
 259         int (*events_discarded) (const struct lib_ring_buffer_config *config,
 260                         struct lib_ring_buffer *bufb,
 261                         uint64_t *events_discarded);
 262         int (*content_size) (const struct lib_ring_buffer_config *config,
 263                         struct lib_ring_buffer *bufb,
 264                         uint64_t *content_size);
 265         int (*packet_size) (const struct lib_ring_buffer_config *config,
 266                         struct lib_ring_buffer *bufb,
 267                         uint64_t *packet_size);
 268         int (*stream_id) (const struct lib_ring_buffer_config *config,
 269                         struct lib_ring_buffer *bufb,
 270                         uint64_t *stream_id);
 271         int (*current_timestamp) (const struct lib_ring_buffer_config *config,
 272                         struct lib_ring_buffer *bufb,
 273                         uint64_t *ts);
 274 };
 275
 276 struct lttng_transport {
 277         char *name;
 278         struct module *owner;
 279         struct list_head node;
 280         struct lttng_channel_ops ops;
 281 };
 282
 283 struct lttng_channel {
 284         unsigned int id;
 285         struct channel *chan;           /* Channel buffers */
 286         int enabled;
 287         struct lttng_ctx *ctx;
 288         /* Event ID management */
 289         struct lttng_session *session;
 290         struct file *file;              /* File associated to channel */
 291         unsigned int free_event_id;     /* Next event ID to allocate */
 292         struct list_head list;          /* Channel list */
 293         struct lttng_channel_ops *ops;
 294         struct lttng_transport *transport;
 295         struct lttng_event **sc_table;  /* for syscall tracing */
 296         struct lttng_event **compat_sc_table;
 297         struct lttng_event *sc_unknown; /* for unknown syscalls */
 298         struct lttng_event *sc_compat_unknown;
 299         struct lttng_event *sc_exit;    /* for syscall exit */
 300         int header_type;                /* 0: unset, 1: compact, 2: large */
 301         enum channel_type channel_type;
 302         unsigned int metadata_dumped:1;
 303 };
 304
 305 struct lttng_metadata_stream {
 306         void *priv;                     /* Ring buffer private data */
 307         struct lttng_metadata_cache *metadata_cache;
 308         unsigned int metadata_in;       /* Bytes read from the cache */
 309         unsigned int metadata_out;      /* Bytes consumed from stream */
 310         int finalized;                  /* Has channel been finalized */
 311         wait_queue_head_t read_wait;    /* Reader buffer-level wait queue */
 312         struct list_head list;          /* Stream list */
 313         struct lttng_transport *transport;
 314 };
 315
 316 struct lttng_session {
 317         int active;                     /* Is trace session active ? */
 318         int been_active;                /* Has trace session been active ? */
 319         struct file *file;              /* File associated to session */
 320         struct list_head chan;          /* Channel list head */
 321         struct list_head events;        /* Event list head */
 322         struct list_head list;          /* Session list */
 323         unsigned int free_chan_id;      /* Next chan ID to allocate */
 324         uuid_le uuid;                   /* Trace session unique ID */
 325         struct lttng_metadata_cache *metadata_cache;
 326         unsigned int metadata_dumped:1;
 327 };
 328
 329 struct lttng_metadata_cache {
 330         char *data;                     /* Metadata cache */
 331         unsigned int cache_alloc;       /* Metadata allocated size (bytes) */
 332         unsigned int metadata_written;  /* Number of bytes written in metadata cache */
 333         struct kref refcount;           /* Metadata cache usage */
 334         struct list_head metadata_stream;       /* Metadata stream list */
 335 };
 336
 337 struct lttng_session *lttng_session_create(void);
 338 int lttng_session_enable(struct lttng_session *session);
 339 int lttng_session_disable(struct lttng_session *session);
 340 void lttng_session_destroy(struct lttng_session *session);
 341 void metadata_cache_destroy(struct kref *kref);
 342
 343 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
 344                                        const char *transport_name,
 345                                        void *buf_addr,
 346                                        size_t subbuf_size, size_t num_subbuf,
 347                                        unsigned int switch_timer_interval,
 348                                        unsigned int read_timer_interval,
 349                                        enum channel_type channel_type);
 350 struct lttng_channel *lttng_global_channel_create(struct lttng_session *session,
 351                                        int overwrite, void *buf_addr,
 352                                        size_t subbuf_size, size_t num_subbuf,
 353                                        unsigned int switch_timer_interval,
 354                                        unsigned int read_timer_interval);
 355
 356 void lttng_metadata_channel_destroy(struct lttng_channel *chan);
 357 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 358                                    struct lttng_kernel_event *event_param,
 359                                    void *filter,
 360                                    const struct lttng_event_desc *internal_desc);
 361 struct lttng_event *lttng_event_compat_old_create(struct lttng_channel *chan,
 362                 struct lttng_kernel_old_event *old_event_param,
 363                 void *filter,
 364                 const struct lttng_event_desc *internal_desc);
 365
 366 int lttng_channel_enable(struct lttng_channel *channel);
 367 int lttng_channel_disable(struct lttng_channel *channel);
 368 int lttng_event_enable(struct lttng_event *event);
 369 int lttng_event_disable(struct lttng_event *event);
 370
 371 void lttng_transport_register(struct lttng_transport *transport);
 372 void lttng_transport_unregister(struct lttng_transport *transport);
 373
 374 void synchronize_trace(void);
 375 int lttng_abi_init(void);
 376 int lttng_abi_compat_old_init(void);
 377 void lttng_abi_exit(void);
 378 void lttng_abi_compat_old_exit(void);
 379
 380 int lttng_probe_register(struct lttng_probe_desc *desc);
 381 void lttng_probe_unregister(struct lttng_probe_desc *desc);
 382 const struct lttng_event_desc *lttng_event_get(const char *name);
 383 void lttng_event_put(const struct lttng_event_desc *desc);
 384 int lttng_probes_init(void);
 385 void lttng_probes_exit(void);
 386
 387 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
 388                 struct channel *chan);
 389
 390 #if defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS)
 391 int lttng_syscalls_register(struct lttng_channel *chan, void *filter);
 392 int lttng_syscalls_unregister(struct lttng_channel *chan);
 393 #else
 394 static inline int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
 395 {
 396         return -ENOSYS;
 397 }
 398
 399 static inline int lttng_syscalls_unregister(struct lttng_channel *chan)
 400 {
 401         return 0;
 402 }
 403 #endif
 404
 405 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx);
 406 int lttng_find_context(struct lttng_ctx *ctx, const char *name);
 407 void lttng_remove_context_field(struct lttng_ctx **ctx,
 408                                 struct lttng_ctx_field *field);
 409 void lttng_destroy_context(struct lttng_ctx *ctx);
 410 int lttng_add_pid_to_ctx(struct lttng_ctx **ctx);
 411 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
 412 int lttng_add_prio_to_ctx(struct lttng_ctx **ctx);
 413 int lttng_add_nice_to_ctx(struct lttng_ctx **ctx);
 414 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
 415 int lttng_add_tid_to_ctx(struct lttng_ctx **ctx);
 416 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
 417 int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx);
 418 int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx);
 419 int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx);
 420 #if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33))
 421 int lttng_add_perf_counter_to_ctx(uint32_t type,
 422                                   uint64_t config,
 423                                   const char *name,
 424                                   struct lttng_ctx **ctx);
 425 #else
 426 static inline
 427 int lttng_add_perf_counter_to_ctx(uint32_t type,
 428                                   uint64_t config,
 429                                   const char *name,
 430                                   struct lttng_ctx **ctx)
 431 {
 432         return -ENOSYS;
 433 }
 434 #endif
 435
 436 int lttng_logger_init(void);
 437 void lttng_logger_exit(void);
 438
 439 extern int lttng_statedump_start(struct lttng_session *session);
 440
 441 #ifdef CONFIG_KPROBES
 442 int lttng_kprobes_register(const char *name,
 443                 const char *symbol_name,
 444                 uint64_t offset,
 445                 uint64_t addr,
 446                 struct lttng_event *event);
 447 void lttng_kprobes_unregister(struct lttng_event *event);
 448 void lttng_kprobes_destroy_private(struct lttng_event *event);
 449 #else
 450 static inline
 451 int lttng_kprobes_register(const char *name,
 452                 const char *symbol_name,
 453                 uint64_t offset,
 454                 uint64_t addr,
 455                 struct lttng_event *event)
 456 {
 457         return -ENOSYS;
 458 }
 459
 460 static inline
 461 void lttng_kprobes_unregister(struct lttng_event *event)
 462 {
 463 }
 464
 465 static inline
 466 void lttng_kprobes_destroy_private(struct lttng_event *event)
 467 {
 468 }
 469 #endif
 470
 471 #ifdef CONFIG_KRETPROBES
 472 int lttng_kretprobes_register(const char *name,
 473                 const char *symbol_name,
 474                 uint64_t offset,
 475                 uint64_t addr,
 476                 struct lttng_event *event_entry,
 477                 struct lttng_event *event_exit);
 478 void lttng_kretprobes_unregister(struct lttng_event *event);
 479 void lttng_kretprobes_destroy_private(struct lttng_event *event);
 480 #else
 481 static inline
 482 int lttng_kretprobes_register(const char *name,
 483                 const char *symbol_name,
 484                 uint64_t offset,
 485                 uint64_t addr,
 486                 struct lttng_event *event_entry,
 487                 struct lttng_event *event_exit)
 488 {
 489         return -ENOSYS;
 490 }
 491
 492 static inline
 493 void lttng_kretprobes_unregister(struct lttng_event *event)
 494 {
 495 }
 496
 497 static inline
 498 void lttng_kretprobes_destroy_private(struct lttng_event *event)
 499 {
 500 }
 501 #endif
 502
 503 #ifdef CONFIG_DYNAMIC_FTRACE
 504 int lttng_ftrace_register(const char *name,
 505                           const char *symbol_name,
 506                           struct lttng_event *event);
 507 void lttng_ftrace_unregister(struct lttng_event *event);
 508 void lttng_ftrace_destroy_private(struct lttng_event *event);
 509 #else
 510 static inline
 511 int lttng_ftrace_register(const char *name,
 512                           const char *symbol_name,
 513                           struct lttng_event *event)
 514 {
 515         return -ENOSYS;
 516 }
 517
 518 static inline
 519 void lttng_ftrace_unregister(struct lttng_event *event)
 520 {
 521 }
 522
 523 static inline
 524 void lttng_ftrace_destroy_private(struct lttng_event *event)
 525 {
 526 }
 527 #endif
 528
 529 int lttng_calibrate(struct lttng_kernel_calibrate *calibrate);
 530
 531 extern const struct file_operations lttng_tracepoint_list_fops;
 532
 533 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35))
 534 #define TRACEPOINT_HAS_DATA_ARG
 535 #endif
 536
 537 #endif /* _LTTNG_EVENTS_H */