lttng-events.h

   1 #ifndef _LTTNG_EVENTS_H
   2 #define _LTTNG_EVENTS_H
   3
   4 /*
   5  * lttng-events.h
   6  *
   7  * Copyright 2010-2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * Holds LTTng per-session event registry.
  10  *
  11  * Dual LGPL v2.1/GPL v2 license.
  12  */
  13
  14 #include <linux/list.h>
  15 #include <linux/kprobes.h>
  16 #include "wrapper/uuid.h"
  17 #include "lttng-abi.h"
  18
  19 #undef is_signed_type
  20 #define is_signed_type(type)            (((type)(-1)) < 0)
  21
  22 struct lttng_channel;
  23 struct lttng_session;
  24 struct lib_ring_buffer_ctx;
  25 struct perf_event;
  26 struct perf_event_attr;
  27
  28 /* Type description */
  29
  30 /* Update the astract_types name table in lttng-types.c along with this enum */
  31 enum abstract_types {
  32         atype_integer,
  33         atype_enum,
  34         atype_array,
  35         atype_sequence,
  36         atype_string,
  37         NR_ABSTRACT_TYPES,
  38 };
  39
  40 /* Update the string_encodings name table in lttng-types.c along with this enum */
  41 enum lttng_string_encodings {
  42         lttng_encode_none = 0,
  43         lttng_encode_UTF8 = 1,
  44         lttng_encode_ASCII = 2,
  45         NR_STRING_ENCODINGS,
  46 };
  47
  48 struct lttng_enum_entry {
  49         unsigned long long start, end;  /* start and end are inclusive */
  50         const char *string;
  51 };
  52
  53 #define __type_integer(_type, _byte_order, _base, _encoding)    \
  54         {                                                       \
  55             .atype = atype_integer,                             \
  56             .u.basic.integer =                                  \
  57                 {                                               \
  58                   .size = sizeof(_type) * CHAR_BIT,             \
  59                   .alignment = lttng_alignof(_type) * CHAR_BIT, \
  60                   .signedness = is_signed_type(_type),          \
  61                   .reverse_byte_order = _byte_order != __BYTE_ORDER,    \
  62                   .base = _base,                                \
  63                   .encoding = lttng_encode_##_encoding,         \
  64                 },                                              \
  65         }                                                       \
  66
  67 struct lttng_integer_type {
  68         unsigned int size;              /* in bits */
  69         unsigned short alignment;       /* in bits */
  70         unsigned int signedness:1,
  71                 reverse_byte_order:1;
  72         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
  73         enum lttng_string_encodings encoding;
  74 };
  75
  76 union _lttng_basic_type {
  77         struct lttng_integer_type integer;
  78         struct {
  79                 const char *name;
  80         } enumeration;
  81         struct {
  82                 enum lttng_string_encodings encoding;
  83         } string;
  84 };
  85
  86 struct lttng_basic_type {
  87         enum abstract_types atype;
  88         union {
  89                 union _lttng_basic_type basic;
  90         } u;
  91 };
  92
  93 struct lttng_type {
  94         enum abstract_types atype;
  95         union {
  96                 union _lttng_basic_type basic;
  97                 struct {
  98                         struct lttng_basic_type elem_type;
  99                         unsigned int length;            /* num. elems. */
 100                 } array;
 101                 struct {
 102                         struct lttng_basic_type length_type;
 103                         struct lttng_basic_type elem_type;
 104                 } sequence;
 105         } u;
 106 };
 107
 108 struct lttng_enum {
 109         const char *name;
 110         struct lttng_type container_type;
 111         const struct lttng_enum_entry *entries;
 112         unsigned int len;
 113 };
 114
 115 /* Event field description */
 116
 117 struct lttng_event_field {
 118         const char *name;
 119         struct lttng_type type;
 120 };
 121
 122 /*
 123  * We need to keep this perf counter field separately from struct
 124  * lttng_ctx_field because cpu hotplug needs fixed-location addresses.
 125  */
 126 struct lttng_perf_counter_field {
 127         struct notifier_block nb;
 128         int hp_enable;
 129         struct perf_event_attr *attr;
 130         struct perf_event **e;  /* per-cpu array */
 131 };
 132
 133 struct lttng_ctx_field {
 134         struct lttng_event_field event_field;
 135         size_t (*get_size)(size_t offset);
 136         void (*record)(struct lttng_ctx_field *field,
 137                        struct lib_ring_buffer_ctx *ctx,
 138                        struct lttng_channel *chan);
 139         union {
 140                 struct lttng_perf_counter_field *perf_counter;
 141         } u;
 142         void (*destroy)(struct lttng_ctx_field *field);
 143 };
 144
 145 struct lttng_ctx {
 146         struct lttng_ctx_field *fields;
 147         unsigned int nr_fields;
 148         unsigned int allocated_fields;
 149 };
 150
 151 struct lttng_event_desc {
 152         const char *name;
 153         void *probe_callback;
 154         const struct lttng_event_ctx *ctx;      /* context */
 155         const struct lttng_event_field *fields; /* event payload */
 156         unsigned int nr_fields;
 157         struct module *owner;
 158 };
 159
 160 struct lttng_probe_desc {
 161         const struct lttng_event_desc **event_desc;
 162         unsigned int nr_events;
 163         struct list_head head;                  /* chain registered probes */
 164 };
 165
 166 struct lttng_krp;                               /* Kretprobe handling */
 167
 168 /*
 169  * lttng_event structure is referred to by the tracing fast path. It must be
 170  * kept small.
 171  */
 172 struct lttng_event {
 173         unsigned int id;
 174         struct lttng_channel *chan;
 175         int enabled;
 176         const struct lttng_event_desc *desc;
 177         void *filter;
 178         struct lttng_ctx *ctx;
 179         enum lttng_kernel_instrumentation instrumentation;
 180         union {
 181                 struct {
 182                         struct kprobe kp;
 183                         char *symbol_name;
 184                 } kprobe;
 185                 struct {
 186                         struct lttng_krp *lttng_krp;
 187                         char *symbol_name;
 188                 } kretprobe;
 189                 struct {
 190                         char *symbol_name;
 191                 } ftrace;
 192         } u;
 193         struct list_head list;          /* Event list */
 194         unsigned int metadata_dumped:1;
 195 };
 196
 197 struct lttng_channel_ops {
 198         struct channel *(*channel_create)(const char *name,
 199                                 struct lttng_channel *lttng_chan,
 200                                 void *buf_addr,
 201                                 size_t subbuf_size, size_t num_subbuf,
 202                                 unsigned int switch_timer_interval,
 203                                 unsigned int read_timer_interval);
 204         void (*channel_destroy)(struct channel *chan);
 205         struct lib_ring_buffer *(*buffer_read_open)(struct channel *chan);
 206         int (*buffer_has_read_closed_stream)(struct channel *chan);
 207         void (*buffer_read_close)(struct lib_ring_buffer *buf);
 208         int (*event_reserve)(struct lib_ring_buffer_ctx *ctx,
 209                              uint32_t event_id);
 210         void (*event_commit)(struct lib_ring_buffer_ctx *ctx);
 211         void (*event_write)(struct lib_ring_buffer_ctx *ctx, const void *src,
 212                             size_t len);
 213         void (*event_write_from_user)(struct lib_ring_buffer_ctx *ctx,
 214                                       const void *src, size_t len);
 215         void (*event_memset)(struct lib_ring_buffer_ctx *ctx,
 216                              int c, size_t len);
 217         /*
 218          * packet_avail_size returns the available size in the current
 219          * packet. Note that the size returned is only a hint, since it
 220          * may change due to concurrent writes.
 221          */
 222         size_t (*packet_avail_size)(struct channel *chan);
 223         wait_queue_head_t *(*get_writer_buf_wait_queue)(struct channel *chan, int cpu);
 224         wait_queue_head_t *(*get_hp_wait_queue)(struct channel *chan);
 225         int (*is_finalized)(struct channel *chan);
 226         int (*is_disabled)(struct channel *chan);
 227 };
 228
 229 struct lttng_transport {
 230         char *name;
 231         struct module *owner;
 232         struct list_head node;
 233         struct lttng_channel_ops ops;
 234 };
 235
 236 struct lttng_channel {
 237         unsigned int id;
 238         struct channel *chan;           /* Channel buffers */
 239         int enabled;
 240         struct lttng_ctx *ctx;
 241         /* Event ID management */
 242         struct lttng_session *session;
 243         struct file *file;              /* File associated to channel */
 244         unsigned int free_event_id;     /* Next event ID to allocate */
 245         struct list_head list;          /* Channel list */
 246         struct lttng_channel_ops *ops;
 247         struct lttng_transport *transport;
 248         struct lttng_event **sc_table;  /* for syscall tracing */
 249         struct lttng_event **compat_sc_table;
 250         struct lttng_event *sc_unknown; /* for unknown syscalls */
 251         struct lttng_event *sc_compat_unknown;
 252         struct lttng_event *sc_exit;    /* for syscall exit */
 253         int header_type;                /* 0: unset, 1: compact, 2: large */
 254         unsigned int metadata_dumped:1;
 255 };
 256
 257 struct lttng_session {
 258         int active;                     /* Is trace session active ? */
 259         int been_active;                /* Has trace session been active ? */
 260         struct file *file;              /* File associated to session */
 261         struct lttng_channel *metadata; /* Metadata channel */
 262         struct list_head chan;          /* Channel list head */
 263         struct list_head events;        /* Event list head */
 264         struct list_head list;          /* Session list */
 265         unsigned int free_chan_id;      /* Next chan ID to allocate */
 266         uuid_le uuid;                   /* Trace session unique ID */
 267         unsigned int metadata_dumped:1;
 268 };
 269
 270 struct lttng_session *lttng_session_create(void);
 271 int lttng_session_enable(struct lttng_session *session);
 272 int lttng_session_disable(struct lttng_session *session);
 273 void lttng_session_destroy(struct lttng_session *session);
 274
 275 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
 276                                        const char *transport_name,
 277                                        void *buf_addr,
 278                                        size_t subbuf_size, size_t num_subbuf,
 279                                        unsigned int switch_timer_interval,
 280                                        unsigned int read_timer_interval);
 281 struct lttng_channel *lttng_global_channel_create(struct lttng_session *session,
 282                                        int overwrite, void *buf_addr,
 283                                        size_t subbuf_size, size_t num_subbuf,
 284                                        unsigned int switch_timer_interval,
 285                                        unsigned int read_timer_interval);
 286
 287 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 288                                    struct lttng_kernel_event *event_param,
 289                                    void *filter,
 290                                    const struct lttng_event_desc *internal_desc);
 291
 292 int lttng_channel_enable(struct lttng_channel *channel);
 293 int lttng_channel_disable(struct lttng_channel *channel);
 294 int lttng_event_enable(struct lttng_event *event);
 295 int lttng_event_disable(struct lttng_event *event);
 296
 297 void lttng_transport_register(struct lttng_transport *transport);
 298 void lttng_transport_unregister(struct lttng_transport *transport);
 299
 300 void synchronize_trace(void);
 301 int lttng_abi_init(void);
 302 void lttng_abi_exit(void);
 303
 304 int lttng_probe_register(struct lttng_probe_desc *desc);
 305 void lttng_probe_unregister(struct lttng_probe_desc *desc);
 306 const struct lttng_event_desc *lttng_event_get(const char *name);
 307 void lttng_event_put(const struct lttng_event_desc *desc);
 308 int lttng_probes_init(void);
 309 void lttng_probes_exit(void);
 310
 311 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 312 int lttng_syscalls_register(struct lttng_channel *chan, void *filter);
 313 int lttng_syscalls_unregister(struct lttng_channel *chan);
 314 #else
 315 static inline int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
 316 {
 317         return -ENOSYS;
 318 }
 319
 320 static inline int lttng_syscalls_unregister(struct lttng_channel *chan)
 321 {
 322         return 0;
 323 }
 324 #endif
 325
 326 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx);
 327 int lttng_find_context(struct lttng_ctx *ctx, const char *name);
 328 void lttng_remove_context_field(struct lttng_ctx **ctx,
 329                                 struct lttng_ctx_field *field);
 330 void lttng_destroy_context(struct lttng_ctx *ctx);
 331 int lttng_add_pid_to_ctx(struct lttng_ctx **ctx);
 332 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
 333 int lttng_add_prio_to_ctx(struct lttng_ctx **ctx);
 334 int lttng_add_nice_to_ctx(struct lttng_ctx **ctx);
 335 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
 336 int lttng_add_tid_to_ctx(struct lttng_ctx **ctx);
 337 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
 338 int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx);
 339 int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx);
 340 #if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33))
 341 int lttng_add_perf_counter_to_ctx(uint32_t type,
 342                                   uint64_t config,
 343                                   const char *name,
 344                                   struct lttng_ctx **ctx);
 345 #else
 346 static inline
 347 int lttng_add_perf_counter_to_ctx(uint32_t type,
 348                                   uint64_t config,
 349                                   const char *name,
 350                                   struct lttng_ctx **ctx)
 351 {
 352         return -ENOSYS;
 353 }
 354 #endif
 355
 356 #ifdef CONFIG_KPROBES
 357 int lttng_kprobes_register(const char *name,
 358                 const char *symbol_name,
 359                 uint64_t offset,
 360                 uint64_t addr,
 361                 struct lttng_event *event);
 362 void lttng_kprobes_unregister(struct lttng_event *event);
 363 void lttng_kprobes_destroy_private(struct lttng_event *event);
 364 #else
 365 static inline
 366 int lttng_kprobes_register(const char *name,
 367                 const char *symbol_name,
 368                 uint64_t offset,
 369                 uint64_t addr,
 370                 struct lttng_event *event)
 371 {
 372         return -ENOSYS;
 373 }
 374
 375 static inline
 376 void lttng_kprobes_unregister(struct lttng_event *event)
 377 {
 378 }
 379
 380 static inline
 381 void lttng_kprobes_destroy_private(struct lttng_event *event)
 382 {
 383 }
 384 #endif
 385
 386 #ifdef CONFIG_KRETPROBES
 387 int lttng_kretprobes_register(const char *name,
 388                 const char *symbol_name,
 389                 uint64_t offset,
 390                 uint64_t addr,
 391                 struct lttng_event *event_entry,
 392                 struct lttng_event *event_exit);
 393 void lttng_kretprobes_unregister(struct lttng_event *event);
 394 void lttng_kretprobes_destroy_private(struct lttng_event *event);
 395 #else
 396 static inline
 397 int lttng_kretprobes_register(const char *name,
 398                 const char *symbol_name,
 399                 uint64_t offset,
 400                 uint64_t addr,
 401                 struct lttng_event *event_entry,
 402                 struct lttng_event *event_exit)
 403 {
 404         return -ENOSYS;
 405 }
 406
 407 static inline
 408 void lttng_kretprobes_unregister(struct lttng_event *event)
 409 {
 410 }
 411
 412 static inline
 413 void lttng_kretprobes_destroy_private(struct lttng_event *event)
 414 {
 415 }
 416 #endif
 417
 418 #ifdef CONFIG_DYNAMIC_FTRACE
 419 int lttng_ftrace_register(const char *name,
 420                           const char *symbol_name,
 421                           struct lttng_event *event);
 422 void lttng_ftrace_unregister(struct lttng_event *event);
 423 void lttng_ftrace_destroy_private(struct lttng_event *event);
 424 #else
 425 static inline
 426 int lttng_ftrace_register(const char *name,
 427                           const char *symbol_name,
 428                           struct lttng_event *event)
 429 {
 430         return -ENOSYS;
 431 }
 432
 433 static inline
 434 void lttng_ftrace_unregister(struct lttng_event *event)
 435 {
 436 }
 437
 438 static inline
 439 void lttng_ftrace_destroy_private(struct lttng_event *event)
 440 {
 441 }
 442 #endif
 443
 444 int lttng_calibrate(struct lttng_kernel_calibrate *calibrate);
 445
 446 extern const struct file_operations lttng_tracepoint_list_fops;
 447
 448 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35))
 449 #define TRACEPOINT_HAS_DATA_ARG
 450 #endif
 451
 452 #endif /* _LTTNG_EVENTS_H */