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;               /* lttng-modules name */
 173         const char *kname;              /* Linux kernel name (tracepoints) */
 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 };
 249
 250 struct lttng_transport {
 251         char *name;
 252         struct module *owner;
 253         struct list_head node;
 254         struct lttng_channel_ops ops;
 255 };
 256
 257 struct lttng_channel {
 258         unsigned int id;
 259         struct channel *chan;           /* Channel buffers */
 260         int enabled;
 261         struct lttng_ctx *ctx;
 262         /* Event ID management */
 263         struct lttng_session *session;
 264         struct file *file;              /* File associated to channel */
 265         unsigned int free_event_id;     /* Next event ID to allocate */
 266         struct list_head list;          /* Channel list */
 267         struct lttng_channel_ops *ops;
 268         struct lttng_transport *transport;
 269         struct lttng_event **sc_table;  /* for syscall tracing */
 270         struct lttng_event **compat_sc_table;
 271         struct lttng_event *sc_unknown; /* for unknown syscalls */
 272         struct lttng_event *sc_compat_unknown;
 273         struct lttng_event *sc_exit;    /* for syscall exit */
 274         int header_type;                /* 0: unset, 1: compact, 2: large */
 275         enum channel_type channel_type;
 276         unsigned int metadata_dumped:1;
 277 };
 278
 279 struct lttng_metadata_stream {
 280         void *priv;                     /* Ring buffer private data */
 281         struct lttng_metadata_cache *metadata_cache;
 282         unsigned int metadata_in;       /* Bytes read from the cache */
 283         unsigned int metadata_out;      /* Bytes consumed from stream */
 284         int finalized;                  /* Has channel been finalized */
 285         wait_queue_head_t read_wait;    /* Reader buffer-level wait queue */
 286         struct list_head list;          /* Stream list */
 287         struct lttng_transport *transport;
 288 };
 289
 290 struct lttng_session {
 291         int active;                     /* Is trace session active ? */
 292         int been_active;                /* Has trace session been active ? */
 293         struct file *file;              /* File associated to session */
 294         struct list_head chan;          /* Channel list head */
 295         struct list_head events;        /* Event list head */
 296         struct list_head list;          /* Session list */
 297         unsigned int free_chan_id;      /* Next chan ID to allocate */
 298         uuid_le uuid;                   /* Trace session unique ID */
 299         struct lttng_metadata_cache *metadata_cache;
 300         unsigned int metadata_dumped:1;
 301 };
 302
 303 struct lttng_metadata_cache {
 304         char *data;                     /* Metadata cache */
 305         unsigned int cache_alloc;       /* Metadata allocated size (bytes) */
 306         unsigned int metadata_written;  /* Number of bytes written in metadata cache */
 307         struct kref refcount;           /* Metadata cache usage */
 308         struct list_head metadata_stream;       /* Metadata stream list */
 309 };
 310
 311 struct lttng_session *lttng_session_create(void);
 312 int lttng_session_enable(struct lttng_session *session);
 313 int lttng_session_disable(struct lttng_session *session);
 314 void lttng_session_destroy(struct lttng_session *session);
 315 void metadata_cache_destroy(struct kref *kref);
 316
 317 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
 318                                        const char *transport_name,
 319                                        void *buf_addr,
 320                                        size_t subbuf_size, size_t num_subbuf,
 321                                        unsigned int switch_timer_interval,
 322                                        unsigned int read_timer_interval,
 323                                        enum channel_type channel_type);
 324 struct lttng_channel *lttng_global_channel_create(struct lttng_session *session,
 325                                        int overwrite, void *buf_addr,
 326                                        size_t subbuf_size, size_t num_subbuf,
 327                                        unsigned int switch_timer_interval,
 328                                        unsigned int read_timer_interval);
 329
 330 void lttng_metadata_channel_destroy(struct lttng_channel *chan);
 331 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 332                                    struct lttng_kernel_event *event_param,
 333                                    void *filter,
 334                                    const struct lttng_event_desc *internal_desc);
 335 struct lttng_event *lttng_event_compat_old_create(struct lttng_channel *chan,
 336                 struct lttng_kernel_old_event *old_event_param,
 337                 void *filter,
 338                 const struct lttng_event_desc *internal_desc);
 339
 340 int lttng_channel_enable(struct lttng_channel *channel);
 341 int lttng_channel_disable(struct lttng_channel *channel);
 342 int lttng_event_enable(struct lttng_event *event);
 343 int lttng_event_disable(struct lttng_event *event);
 344
 345 void lttng_transport_register(struct lttng_transport *transport);
 346 void lttng_transport_unregister(struct lttng_transport *transport);
 347
 348 void synchronize_trace(void);
 349 int lttng_abi_init(void);
 350 int lttng_abi_compat_old_init(void);
 351 void lttng_abi_exit(void);
 352 void lttng_abi_compat_old_exit(void);
 353
 354 int lttng_probe_register(struct lttng_probe_desc *desc);
 355 void lttng_probe_unregister(struct lttng_probe_desc *desc);
 356 const struct lttng_event_desc *lttng_event_get(const char *name);
 357 void lttng_event_put(const struct lttng_event_desc *desc);
 358 int lttng_probes_init(void);
 359 void lttng_probes_exit(void);
 360
 361 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
 362                 struct channel *chan);
 363
 364 #if defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS)
 365 int lttng_syscalls_register(struct lttng_channel *chan, void *filter);
 366 int lttng_syscalls_unregister(struct lttng_channel *chan);
 367 #else
 368 static inline int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
 369 {
 370         return -ENOSYS;
 371 }
 372
 373 static inline int lttng_syscalls_unregister(struct lttng_channel *chan)
 374 {
 375         return 0;
 376 }
 377 #endif
 378
 379 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx);
 380 int lttng_find_context(struct lttng_ctx *ctx, const char *name);
 381 void lttng_remove_context_field(struct lttng_ctx **ctx,
 382                                 struct lttng_ctx_field *field);
 383 void lttng_destroy_context(struct lttng_ctx *ctx);
 384 int lttng_add_pid_to_ctx(struct lttng_ctx **ctx);
 385 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
 386 int lttng_add_prio_to_ctx(struct lttng_ctx **ctx);
 387 int lttng_add_nice_to_ctx(struct lttng_ctx **ctx);
 388 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
 389 int lttng_add_tid_to_ctx(struct lttng_ctx **ctx);
 390 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
 391 int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx);
 392 int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx);
 393 int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx);
 394 #if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33))
 395 int lttng_add_perf_counter_to_ctx(uint32_t type,
 396                                   uint64_t config,
 397                                   const char *name,
 398                                   struct lttng_ctx **ctx);
 399 #else
 400 static inline
 401 int lttng_add_perf_counter_to_ctx(uint32_t type,
 402                                   uint64_t config,
 403                                   const char *name,
 404                                   struct lttng_ctx **ctx)
 405 {
 406         return -ENOSYS;
 407 }
 408 #endif
 409
 410 extern int lttng_statedump_start(struct lttng_session *session);
 411
 412 #ifdef CONFIG_KPROBES
 413 int lttng_kprobes_register(const char *name,
 414                 const char *symbol_name,
 415                 uint64_t offset,
 416                 uint64_t addr,
 417                 struct lttng_event *event);
 418 void lttng_kprobes_unregister(struct lttng_event *event);
 419 void lttng_kprobes_destroy_private(struct lttng_event *event);
 420 #else
 421 static inline
 422 int lttng_kprobes_register(const char *name,
 423                 const char *symbol_name,
 424                 uint64_t offset,
 425                 uint64_t addr,
 426                 struct lttng_event *event)
 427 {
 428         return -ENOSYS;
 429 }
 430
 431 static inline
 432 void lttng_kprobes_unregister(struct lttng_event *event)
 433 {
 434 }
 435
 436 static inline
 437 void lttng_kprobes_destroy_private(struct lttng_event *event)
 438 {
 439 }
 440 #endif
 441
 442 #ifdef CONFIG_KRETPROBES
 443 int lttng_kretprobes_register(const char *name,
 444                 const char *symbol_name,
 445                 uint64_t offset,
 446                 uint64_t addr,
 447                 struct lttng_event *event_entry,
 448                 struct lttng_event *event_exit);
 449 void lttng_kretprobes_unregister(struct lttng_event *event);
 450 void lttng_kretprobes_destroy_private(struct lttng_event *event);
 451 #else
 452 static inline
 453 int lttng_kretprobes_register(const char *name,
 454                 const char *symbol_name,
 455                 uint64_t offset,
 456                 uint64_t addr,
 457                 struct lttng_event *event_entry,
 458                 struct lttng_event *event_exit)
 459 {
 460         return -ENOSYS;
 461 }
 462
 463 static inline
 464 void lttng_kretprobes_unregister(struct lttng_event *event)
 465 {
 466 }
 467
 468 static inline
 469 void lttng_kretprobes_destroy_private(struct lttng_event *event)
 470 {
 471 }
 472 #endif
 473
 474 #ifdef CONFIG_DYNAMIC_FTRACE
 475 int lttng_ftrace_register(const char *name,
 476                           const char *symbol_name,
 477                           struct lttng_event *event);
 478 void lttng_ftrace_unregister(struct lttng_event *event);
 479 void lttng_ftrace_destroy_private(struct lttng_event *event);
 480 #else
 481 static inline
 482 int lttng_ftrace_register(const char *name,
 483                           const char *symbol_name,
 484                           struct lttng_event *event)
 485 {
 486         return -ENOSYS;
 487 }
 488
 489 static inline
 490 void lttng_ftrace_unregister(struct lttng_event *event)
 491 {
 492 }
 493
 494 static inline
 495 void lttng_ftrace_destroy_private(struct lttng_event *event)
 496 {
 497 }
 498 #endif
 499
 500 int lttng_calibrate(struct lttng_kernel_calibrate *calibrate);
 501
 502 extern const struct file_operations lttng_tracepoint_list_fops;
 503
 504 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35))
 505 #define TRACEPOINT_HAS_DATA_ARG
 506 #endif
 507
 508 #endif /* _LTTNG_EVENTS_H */