ltt-events.h

   1 #ifndef _LTT_EVENTS_H
   2 #define _LTT_EVENTS_H
   3
   4 /*
   5  * ltt-events.h
   6  *
   7  * Copyright 2010 (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 "ltt-debugfs-abi.h"
  18
  19 #undef is_signed_type
  20 #define is_signed_type(type)            (((type)(-1)) < 0)
  21
  22 struct ltt_channel;
  23 struct ltt_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 = ltt_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         unsigned int 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 ltt_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  * ltt_event structure is referred to by the tracing fast path. It must be
 170  * kept small.
 171  */
 172 struct ltt_event {
 173         unsigned int id;
 174         struct ltt_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         int metadata_dumped:1;
 195 };
 196
 197 struct ltt_channel_ops {
 198         struct channel *(*channel_create)(const char *name,
 199                                 struct ltt_channel *ltt_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         /*
 214          * packet_avail_size returns the available size in the current
 215          * packet. Note that the size returned is only a hint, since it
 216          * may change due to concurrent writes.
 217          */
 218         size_t (*packet_avail_size)(struct channel *chan);
 219         wait_queue_head_t *(*get_reader_wait_queue)(struct channel *chan);
 220         wait_queue_head_t *(*get_hp_wait_queue)(struct channel *chan);
 221         int (*is_finalized)(struct channel *chan);
 222         int (*is_disabled)(struct channel *chan);
 223 };
 224
 225 struct ltt_transport {
 226         char *name;
 227         struct module *owner;
 228         struct list_head node;
 229         struct ltt_channel_ops ops;
 230 };
 231
 232 struct ltt_channel {
 233         unsigned int id;
 234         struct channel *chan;           /* Channel buffers */
 235         int enabled;
 236         struct lttng_ctx *ctx;
 237         /* Event ID management */
 238         struct ltt_session *session;
 239         struct file *file;              /* File associated to channel */
 240         unsigned int free_event_id;     /* Next event ID to allocate */
 241         struct list_head list;          /* Channel list */
 242         struct ltt_channel_ops *ops;
 243         struct ltt_transport *transport;
 244         int header_type;                /* 0: unset, 1: compact, 2: large */
 245         int metadata_dumped:1;
 246 };
 247
 248 struct ltt_session {
 249         int active;                     /* Is trace session active ? */
 250         int been_active;                /* Has trace session been active ? */
 251         struct file *file;              /* File associated to session */
 252         struct ltt_channel *metadata;   /* Metadata channel */
 253         struct list_head chan;          /* Channel list head */
 254         struct list_head events;        /* Event list head */
 255         struct list_head list;          /* Session list */
 256         unsigned int free_chan_id;      /* Next chan ID to allocate */
 257         uuid_le uuid;                   /* Trace session unique ID */
 258         int metadata_dumped:1;
 259 };
 260
 261 struct ltt_session *ltt_session_create(void);
 262 int ltt_session_enable(struct ltt_session *session);
 263 int ltt_session_disable(struct ltt_session *session);
 264 void ltt_session_destroy(struct ltt_session *session);
 265
 266 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 267                                        const char *transport_name,
 268                                        void *buf_addr,
 269                                        size_t subbuf_size, size_t num_subbuf,
 270                                        unsigned int switch_timer_interval,
 271                                        unsigned int read_timer_interval);
 272 struct ltt_channel *ltt_global_channel_create(struct ltt_session *session,
 273                                        int overwrite, void *buf_addr,
 274                                        size_t subbuf_size, size_t num_subbuf,
 275                                        unsigned int switch_timer_interval,
 276                                        unsigned int read_timer_interval);
 277
 278 struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 279                                    struct lttng_kernel_event *event_param,
 280                                    void *filter);
 281
 282 int ltt_channel_enable(struct ltt_channel *channel);
 283 int ltt_channel_disable(struct ltt_channel *channel);
 284 int ltt_event_enable(struct ltt_event *event);
 285 int ltt_event_disable(struct ltt_event *event);
 286
 287 void ltt_transport_register(struct ltt_transport *transport);
 288 void ltt_transport_unregister(struct ltt_transport *transport);
 289
 290 void synchronize_trace(void);
 291 int ltt_debugfs_abi_init(void);
 292 void ltt_debugfs_abi_exit(void);
 293
 294 int ltt_probe_register(struct lttng_probe_desc *desc);
 295 void ltt_probe_unregister(struct lttng_probe_desc *desc);
 296 const struct lttng_event_desc *ltt_event_get(const char *name);
 297 void ltt_event_put(const struct lttng_event_desc *desc);
 298 int ltt_probes_init(void);
 299 void ltt_probes_exit(void);
 300 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx);
 301 int lttng_find_context(struct lttng_ctx *ctx, const char *name);
 302 void lttng_remove_context_field(struct lttng_ctx **ctx,
 303                                 struct lttng_ctx_field *field);
 304 void lttng_destroy_context(struct lttng_ctx *ctx);
 305 int lttng_add_pid_to_ctx(struct lttng_ctx **ctx);
 306 int lttng_add_comm_to_ctx(struct lttng_ctx **ctx);
 307 int lttng_add_prio_to_ctx(struct lttng_ctx **ctx);
 308 int lttng_add_nice_to_ctx(struct lttng_ctx **ctx);
 309 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
 310 int lttng_add_tid_to_ctx(struct lttng_ctx **ctx);
 311 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
 312 int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx);
 313 int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx);
 314 #ifdef CONFIG_PERF_EVENTS
 315 int lttng_add_perf_counter_to_ctx(uint32_t type,
 316                                   uint64_t config,
 317                                   const char *name,
 318                                   struct lttng_ctx **ctx);
 319 #else
 320 static inline
 321 int lttng_add_perf_counter_to_ctx(uint32_t type,
 322                                   uint64_t config,
 323                                   const char *name,
 324                                   struct lttng_ctx **ctx)
 325 {
 326         return -ENOSYS;
 327 }
 328 #endif
 329
 330 #ifdef CONFIG_KPROBES
 331 int lttng_kprobes_register(const char *name,
 332                 const char *symbol_name,
 333                 uint64_t offset,
 334                 uint64_t addr,
 335                 struct ltt_event *event);
 336 void lttng_kprobes_unregister(struct ltt_event *event);
 337 void lttng_kprobes_destroy_private(struct ltt_event *event);
 338 #else
 339 static inline
 340 int lttng_kprobes_register(const char *name,
 341                 const char *symbol_name,
 342                 uint64_t offset,
 343                 uint64_t addr,
 344                 struct ltt_event *event)
 345 {
 346         return -ENOSYS;
 347 }
 348
 349 static inline
 350 void lttng_kprobes_unregister(struct ltt_event *event)
 351 {
 352 }
 353
 354 static inline
 355 void lttng_kprobes_destroy_private(struct ltt_event *event)
 356 {
 357 }
 358 #endif
 359
 360 #ifdef CONFIG_KRETPROBES
 361 int lttng_kretprobes_register(const char *name,
 362                 const char *symbol_name,
 363                 uint64_t offset,
 364                 uint64_t addr,
 365                 struct ltt_event *event_entry,
 366                 struct ltt_event *event_exit);
 367 void lttng_kretprobes_unregister(struct ltt_event *event);
 368 void lttng_kretprobes_destroy_private(struct ltt_event *event);
 369 #else
 370 static inline
 371 int lttng_kretprobes_register(const char *name,
 372                 const char *symbol_name,
 373                 uint64_t offset,
 374                 uint64_t addr,
 375                 struct ltt_event *event_entry,
 376                 struct ltt_event *event_exit)
 377 {
 378         return -ENOSYS;
 379 }
 380
 381 static inline
 382 void lttng_kretprobes_unregister(struct ltt_event *event)
 383 {
 384 }
 385
 386 static inline
 387 void lttng_kretprobes_destroy_private(struct ltt_event *event)
 388 {
 389 }
 390 #endif
 391
 392 #ifdef CONFIG_DYNAMIC_FTRACE
 393 int lttng_ftrace_register(const char *name,
 394                           const char *symbol_name,
 395                           struct ltt_event *event);
 396 void lttng_ftrace_unregister(struct ltt_event *event);
 397 void lttng_ftrace_destroy_private(struct ltt_event *event);
 398 #else
 399 static inline
 400 int lttng_ftrace_register(const char *name,
 401                           const char *symbol_name,
 402                           struct ltt_event *event)
 403 {
 404         return -ENOSYS;
 405 }
 406
 407 static inline
 408 void lttng_ftrace_unregister(struct ltt_event *event)
 409 {
 410 }
 411
 412 static inline
 413 void lttng_ftrace_destroy_private(struct ltt_event *event)
 414 {
 415 }
 416 #endif
 417
 418 extern const struct file_operations lttng_tracepoint_list_fops;
 419
 420 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35))
 421 #define TRACEPOINT_HAS_DATA_ARG
 422 #endif
 423
 424 #endif /* _LTT_EVENTS_H */