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