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