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         size_t largest_align;   /* in bytes */
 171 };
 172
 173 struct lttng_event_desc {
 174         const char *name;               /* lttng-modules name */
 175         const char *kname;              /* Linux kernel name (tracepoints) */
 176         void *probe_callback;
 177         const struct lttng_event_ctx *ctx;      /* context */
 178         const struct lttng_event_field *fields; /* event payload */
 179         unsigned int nr_fields;
 180         struct module *owner;
 181 };
 182
 183 struct lttng_probe_desc {
 184         const struct lttng_event_desc **event_desc;
 185         unsigned int nr_events;
 186         struct list_head head;                  /* chain registered probes */
 187 };
 188
 189 struct lttng_krp;                               /* Kretprobe handling */
 190
 191 /*
 192  * lttng_event structure is referred to by the tracing fast path. It must be
 193  * kept small.
 194  */
 195 struct lttng_event {
 196         unsigned int id;
 197         struct lttng_channel *chan;
 198         int enabled;
 199         const struct lttng_event_desc *desc;
 200         void *filter;
 201         struct lttng_ctx *ctx;
 202         enum lttng_kernel_instrumentation instrumentation;
 203         union {
 204                 struct {
 205                         struct kprobe kp;
 206                         char *symbol_name;
 207                 } kprobe;
 208                 struct {
 209                         struct lttng_krp *lttng_krp;
 210                         char *symbol_name;
 211                 } kretprobe;
 212                 struct {
 213                         char *symbol_name;
 214                 } ftrace;
 215         } u;
 216         struct list_head list;          /* Event list */
 217         unsigned int metadata_dumped:1;
 218 };
 219
 220 struct lttng_channel_ops {
 221         struct channel *(*channel_create)(const char *name,
 222                                 struct lttng_channel *lttng_chan,
 223                                 void *buf_addr,
 224                                 size_t subbuf_size, size_t num_subbuf,
 225                                 unsigned int switch_timer_interval,
 226                                 unsigned int read_timer_interval);
 227         void (*channel_destroy)(struct channel *chan);
 228         struct lib_ring_buffer *(*buffer_read_open)(struct channel *chan);
 229         int (*buffer_has_read_closed_stream)(struct channel *chan);
 230         void (*buffer_read_close)(struct lib_ring_buffer *buf);
 231         int (*event_reserve)(struct lib_ring_buffer_ctx *ctx,
 232                              uint32_t event_id);
 233         void (*event_commit)(struct lib_ring_buffer_ctx *ctx);
 234         void (*event_write)(struct lib_ring_buffer_ctx *ctx, const void *src,
 235                             size_t len);
 236         void (*event_write_from_user)(struct lib_ring_buffer_ctx *ctx,
 237                                       const void *src, size_t len);
 238         void (*event_memset)(struct lib_ring_buffer_ctx *ctx,
 239                              int c, size_t len);
 240         void (*event_strcpy)(struct lib_ring_buffer_ctx *ctx, const char *src,
 241                              size_t len);
 242         void (*event_strcpy_from_user)(struct lib_ring_buffer_ctx *ctx,
 243                                        const char __user *src, size_t len);
 244         /*
 245          * packet_avail_size returns the available size in the current
 246          * packet. Note that the size returned is only a hint, since it
 247          * may change due to concurrent writes.
 248          */
 249         size_t (*packet_avail_size)(struct channel *chan);
 250         wait_queue_head_t *(*get_writer_buf_wait_queue)(struct channel *chan, int cpu);
 251         wait_queue_head_t *(*get_hp_wait_queue)(struct channel *chan);
 252         int (*is_finalized)(struct channel *chan);
 253         int (*is_disabled)(struct channel *chan);
 254         int (*timestamp_begin) (const struct lib_ring_buffer_config *config,
 255                         struct lib_ring_buffer *bufb,
 256                         uint64_t *timestamp_begin);
 257         int (*timestamp_end) (const struct lib_ring_buffer_config *config,
 258                         struct lib_ring_buffer *bufb,
 259                         uint64_t *timestamp_end);
 260         int (*events_discarded) (const struct lib_ring_buffer_config *config,
 261                         struct lib_ring_buffer *bufb,
 262                         uint64_t *events_discarded);
 263         int (*content_size) (const struct lib_ring_buffer_config *config,
 264                         struct lib_ring_buffer *bufb,
 265                         uint64_t *content_size);
 266         int (*packet_size) (const struct lib_ring_buffer_config *config,
 267                         struct lib_ring_buffer *bufb,
 268                         uint64_t *packet_size);
 269         int (*stream_id) (const struct lib_ring_buffer_config *config,
 270                         struct lib_ring_buffer *bufb,
 271                         uint64_t *stream_id);
 272         int (*current_timestamp) (const struct lib_ring_buffer_config *config,
 273                         struct lib_ring_buffer *bufb,
 274                         uint64_t *ts);
 275 };
 276
 277 struct lttng_transport {
 278         char *name;
 279         struct module *owner;
 280         struct list_head node;
 281         struct lttng_channel_ops ops;
 282 };
 283
 284 struct lttng_syscall_filter;
 285
 286 struct lttng_channel {
 287         unsigned int id;
 288         struct channel *chan;           /* Channel buffers */
 289         int enabled;
 290         struct lttng_ctx *ctx;
 291         /* Event ID management */
 292         struct lttng_session *session;
 293         struct file *file;              /* File associated to channel */
 294         unsigned int free_event_id;     /* Next event ID to allocate */
 295         struct list_head list;          /* Channel list */
 296         struct lttng_channel_ops *ops;
 297         struct lttng_transport *transport;
 298         struct lttng_event **sc_table;  /* for syscall tracing */
 299         struct lttng_event **compat_sc_table;
 300         struct lttng_event **sc_exit_table;     /* for syscall exit tracing */
 301         struct lttng_event **compat_sc_exit_table;
 302         struct lttng_event *sc_unknown; /* for unknown syscalls */
 303         struct lttng_event *sc_compat_unknown;
 304         struct lttng_event *sc_exit_unknown;
 305         struct lttng_event *compat_sc_exit_unknown;
 306         struct lttng_syscall_filter *sc_filter;
 307         int header_type;                /* 0: unset, 1: compact, 2: large */
 308         enum channel_type channel_type;
 309         unsigned int metadata_dumped:1,
 310                 sys_enter_registered:1,
 311                 sys_exit_registered:1,
 312                 syscall_all:1;
 313 };
 314
 315 struct lttng_metadata_stream {
 316         void *priv;                     /* Ring buffer private data */
 317         struct lttng_metadata_cache *metadata_cache;
 318         unsigned int metadata_in;       /* Bytes read from the cache */
 319         unsigned int metadata_out;      /* Bytes consumed from stream */
 320         int finalized;                  /* Has channel been finalized */
 321         wait_queue_head_t read_wait;    /* Reader buffer-level wait queue */
 322         struct list_head list;          /* Stream list */
 323         struct lttng_transport *transport;
 324         struct mutex lock;
 325 };
 326
 327
 328 /*
 329  * struct lttng_pid_tracker declared in header due to deferencing of *v
 330  * in RCU_INITIALIZER(v).
 331  */
 332 #define LTTNG_PID_HASH_BITS     6
 333 #define LTTNG_PID_TABLE_SIZE    (1 << LTTNG_PID_HASH_BITS)
 334
 335 struct lttng_pid_tracker {
 336         struct hlist_head pid_hash[LTTNG_PID_TABLE_SIZE];
 337 };
 338
 339 struct lttng_session {
 340         int active;                     /* Is trace session active ? */
 341         int been_active;                /* Has trace session been active ? */
 342         struct file *file;              /* File associated to session */
 343         struct list_head chan;          /* Channel list head */
 344         struct list_head events;        /* Event list head */
 345         struct list_head list;          /* Session list */
 346         unsigned int free_chan_id;      /* Next chan ID to allocate */
 347         uuid_le uuid;                   /* Trace session unique ID */
 348         struct lttng_metadata_cache *metadata_cache;
 349         struct lttng_pid_tracker *pid_tracker;
 350         unsigned int metadata_dumped:1;
 351 };
 352
 353 struct lttng_metadata_cache {
 354         char *data;                     /* Metadata cache */
 355         unsigned int cache_alloc;       /* Metadata allocated size (bytes) */
 356         unsigned int metadata_written;  /* Number of bytes written in metadata cache */
 357         struct kref refcount;           /* Metadata cache usage */
 358         struct list_head metadata_stream;       /* Metadata stream list */
 359         uuid_le uuid;                   /* Trace session unique ID (copy) */
 360 };
 361
 362 struct lttng_session *lttng_session_create(void);
 363 int lttng_session_enable(struct lttng_session *session);
 364 int lttng_session_disable(struct lttng_session *session);
 365 void lttng_session_destroy(struct lttng_session *session);
 366 void metadata_cache_destroy(struct kref *kref);
 367
 368 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
 369                                        const char *transport_name,
 370                                        void *buf_addr,
 371                                        size_t subbuf_size, size_t num_subbuf,
 372                                        unsigned int switch_timer_interval,
 373                                        unsigned int read_timer_interval,
 374                                        enum channel_type channel_type);
 375 struct lttng_channel *lttng_global_channel_create(struct lttng_session *session,
 376                                        int overwrite, void *buf_addr,
 377                                        size_t subbuf_size, size_t num_subbuf,
 378                                        unsigned int switch_timer_interval,
 379                                        unsigned int read_timer_interval);
 380
 381 void lttng_metadata_channel_destroy(struct lttng_channel *chan);
 382 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 383                                    struct lttng_kernel_event *event_param,
 384                                    void *filter,
 385                                    const struct lttng_event_desc *internal_desc);
 386 struct lttng_event *lttng_event_compat_old_create(struct lttng_channel *chan,
 387                 struct lttng_kernel_old_event *old_event_param,
 388                 void *filter,
 389                 const struct lttng_event_desc *internal_desc);
 390
 391 int lttng_channel_enable(struct lttng_channel *channel);
 392 int lttng_channel_disable(struct lttng_channel *channel);
 393 int lttng_event_enable(struct lttng_event *event);
 394 int lttng_event_disable(struct lttng_event *event);
 395
 396 void lttng_transport_register(struct lttng_transport *transport);
 397 void lttng_transport_unregister(struct lttng_transport *transport);
 398
 399 void synchronize_trace(void);
 400 int lttng_abi_init(void);
 401 int lttng_abi_compat_old_init(void);
 402 void lttng_abi_exit(void);
 403 void lttng_abi_compat_old_exit(void);
 404
 405 int lttng_probe_register(struct lttng_probe_desc *desc);
 406 void lttng_probe_unregister(struct lttng_probe_desc *desc);
 407 const struct lttng_event_desc *lttng_event_get(const char *name);
 408 void lttng_event_put(const struct lttng_event_desc *desc);
 409 int lttng_probes_init(void);
 410 void lttng_probes_exit(void);
 411
 412 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
 413                 struct channel *chan);
 414
 415 struct lttng_pid_tracker *lttng_pid_tracker_create(void);
 416 void lttng_pid_tracker_destroy(struct lttng_pid_tracker *lpf);
 417 bool lttng_pid_tracker_lookup(struct lttng_pid_tracker *lpf, int pid);
 418 int lttng_pid_tracker_add(struct lttng_pid_tracker *lpf, int pid);
 419 int lttng_pid_tracker_del(struct lttng_pid_tracker *lpf, int pid);
 420
 421 int lttng_session_track_pid(struct lttng_session *session, int pid);
 422 int lttng_session_untrack_pid(struct lttng_session *session, int pid);
 423
 424 #if defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS)
 425 int lttng_syscalls_register(struct lttng_channel *chan, void *filter);
 426 int lttng_syscalls_unregister(struct lttng_channel *chan);
 427 int lttng_syscall_filter_enable(struct lttng_channel *chan,
 428                 const char *name);
 429 int lttng_syscall_filter_disable(struct lttng_channel *chan,
 430                 const char *name);
 431 long lttng_channel_syscall_mask(struct lttng_channel *channel,
 432                 struct lttng_kernel_syscall_mask __user *usyscall_mask);
 433 int lttng_abi_syscall_list(void);
 434 #else
 435 static inline int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
 436 {
 437         return -ENOSYS;
 438 }
 439
 440 static inline int lttng_syscalls_unregister(struct lttng_channel *chan)
 441 {
 442         return 0;
 443 }
 444
 445 static inline
 446 int lttng_syscall_filter_enable(struct lttng_channel *chan,
 447                 const char *name)
 448 {
 449         return -ENOSYS;
 450 }
 451
 452 static inline
 453 int lttng_syscall_filter_disable(struct lttng_channel *chan,
 454                 const char *name)
 455 {
 456         return -ENOSYS;
 457 }
 458
 459 static inline
 460 long lttng_channel_syscall_mask(struct lttng_channel *channel,
 461                 struct lttng_kernel_syscall_mask __user *usyscall_mask)
 462 {
 463         return -ENOSYS;
 464 }
 465
 466 static inline
 467 int lttng_abi_syscall_list(void)
 468 {
 469         return -ENOSYS;
 470 }
 471 #endif
 472
 473 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx);
 474 void lttng_context_update(struct lttng_ctx *ctx);
 475 int lttng_find_context(struct lttng_ctx *ctx, const char *name);
 476 void lttng_remove_context_field(struct lttng_ctx **ctx,
 477                                 struct lttng_ctx_field *field);
 478 void lttng_destroy_context(struct lttng_ctx *ctx);
 479 int lttng_add_pid_to_ctx(struct lttng_ctx **ctx);
 480 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
 481 int lttng_add_prio_to_ctx(struct lttng_ctx **ctx);
 482 int lttng_add_nice_to_ctx(struct lttng_ctx **ctx);
 483 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
 484 int lttng_add_tid_to_ctx(struct lttng_ctx **ctx);
 485 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
 486 int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx);
 487 int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx);
 488 int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx);
 489 #if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33))
 490 int lttng_add_perf_counter_to_ctx(uint32_t type,
 491                                   uint64_t config,
 492                                   const char *name,
 493                                   struct lttng_ctx **ctx);
 494 #else
 495 static inline
 496 int lttng_add_perf_counter_to_ctx(uint32_t type,
 497                                   uint64_t config,
 498                                   const char *name,
 499                                   struct lttng_ctx **ctx)
 500 {
 501         return -ENOSYS;
 502 }
 503 #endif
 504
 505 int lttng_logger_init(void);
 506 void lttng_logger_exit(void);
 507
 508 extern int lttng_statedump_start(struct lttng_session *session);
 509
 510 #ifdef CONFIG_KPROBES
 511 int lttng_kprobes_register(const char *name,
 512                 const char *symbol_name,
 513                 uint64_t offset,
 514                 uint64_t addr,
 515                 struct lttng_event *event);
 516 void lttng_kprobes_unregister(struct lttng_event *event);
 517 void lttng_kprobes_destroy_private(struct lttng_event *event);
 518 #else
 519 static inline
 520 int lttng_kprobes_register(const char *name,
 521                 const char *symbol_name,
 522                 uint64_t offset,
 523                 uint64_t addr,
 524                 struct lttng_event *event)
 525 {
 526         return -ENOSYS;
 527 }
 528
 529 static inline
 530 void lttng_kprobes_unregister(struct lttng_event *event)
 531 {
 532 }
 533
 534 static inline
 535 void lttng_kprobes_destroy_private(struct lttng_event *event)
 536 {
 537 }
 538 #endif
 539
 540 #ifdef CONFIG_KRETPROBES
 541 int lttng_kretprobes_register(const char *name,
 542                 const char *symbol_name,
 543                 uint64_t offset,
 544                 uint64_t addr,
 545                 struct lttng_event *event_entry,
 546                 struct lttng_event *event_exit);
 547 void lttng_kretprobes_unregister(struct lttng_event *event);
 548 void lttng_kretprobes_destroy_private(struct lttng_event *event);
 549 #else
 550 static inline
 551 int lttng_kretprobes_register(const char *name,
 552                 const char *symbol_name,
 553                 uint64_t offset,
 554                 uint64_t addr,
 555                 struct lttng_event *event_entry,
 556                 struct lttng_event *event_exit)
 557 {
 558         return -ENOSYS;
 559 }
 560
 561 static inline
 562 void lttng_kretprobes_unregister(struct lttng_event *event)
 563 {
 564 }
 565
 566 static inline
 567 void lttng_kretprobes_destroy_private(struct lttng_event *event)
 568 {
 569 }
 570 #endif
 571
 572 #ifdef CONFIG_DYNAMIC_FTRACE
 573 int lttng_ftrace_register(const char *name,
 574                           const char *symbol_name,
 575                           struct lttng_event *event);
 576 void lttng_ftrace_unregister(struct lttng_event *event);
 577 void lttng_ftrace_destroy_private(struct lttng_event *event);
 578 #else
 579 static inline
 580 int lttng_ftrace_register(const char *name,
 581                           const char *symbol_name,
 582                           struct lttng_event *event)
 583 {
 584         return -ENOSYS;
 585 }
 586
 587 static inline
 588 void lttng_ftrace_unregister(struct lttng_event *event)
 589 {
 590 }
 591
 592 static inline
 593 void lttng_ftrace_destroy_private(struct lttng_event *event)
 594 {
 595 }
 596 #endif
 597
 598 int lttng_calibrate(struct lttng_kernel_calibrate *calibrate);
 599
 600 extern const struct file_operations lttng_tracepoint_list_fops;
 601 extern const struct file_operations lttng_syscall_list_fops;
 602
 603 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35))
 604 #define TRACEPOINT_HAS_DATA_ARG
 605 #endif
 606
 607 #endif /* _LTTNG_EVENTS_H */