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