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/uuid.h>
  16 #include <linux/kprobes.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 struct lttng_ctx_field {
 123         struct lttng_event_field event_field;
 124         size_t (*get_size)(size_t offset);
 125         void (*record)(struct lttng_ctx_field *field,
 126                        struct lib_ring_buffer_ctx *ctx,
 127                        struct ltt_channel *chan);
 128         union {
 129                 struct {
 130                         struct perf_event **e;  /* per-cpu array */
 131                         struct list_head head;
 132                         struct perf_event_attr *attr;
 133                 } perf_counter;
 134         } u;
 135         void (*destroy)(struct lttng_ctx_field *field);
 136 };
 137
 138 struct lttng_ctx {
 139         struct lttng_ctx_field *fields;
 140         unsigned int nr_fields;
 141         unsigned int allocated_fields;
 142 };
 143
 144 struct lttng_event_desc {
 145         const char *name;
 146         void *probe_callback;
 147         const struct lttng_event_ctx *ctx;      /* context */
 148         const struct lttng_event_field *fields; /* event payload */
 149         unsigned int nr_fields;
 150         struct module *owner;
 151 };
 152
 153 struct lttng_probe_desc {
 154         const struct lttng_event_desc *event_desc;
 155         unsigned int nr_events;
 156         struct list_head head;                  /* chain registered probes */
 157 };
 158
 159 /*
 160  * ltt_event structure is referred to by the tracing fast path. It must be
 161  * kept small.
 162  */
 163 struct ltt_event {
 164         unsigned int id;
 165         struct ltt_channel *chan;
 166         const struct lttng_event_desc *desc;
 167         void *filter;
 168         struct lttng_ctx *ctx;
 169         enum lttng_kernel_instrumentation instrumentation;
 170         union {
 171                 struct {
 172                         struct kprobe kp;
 173                         char *symbol_name;
 174                 } kprobe;
 175                 struct {
 176                         char *symbol_name;
 177                 } ftrace;
 178         } u;
 179         struct list_head list;          /* Event list */
 180         int metadata_dumped:1;
 181 };
 182
 183 struct ltt_channel_ops {
 184         struct channel *(*channel_create)(const char *name,
 185                                 struct ltt_channel *ltt_chan,
 186                                 void *buf_addr,
 187                                 size_t subbuf_size, size_t num_subbuf,
 188                                 unsigned int switch_timer_interval,
 189                                 unsigned int read_timer_interval);
 190         void (*channel_destroy)(struct channel *chan);
 191         struct lib_ring_buffer *(*buffer_read_open)(struct channel *chan);
 192         void (*buffer_read_close)(struct lib_ring_buffer *buf);
 193         int (*event_reserve)(struct lib_ring_buffer_ctx *ctx,
 194                              uint32_t event_id);
 195         void (*event_commit)(struct lib_ring_buffer_ctx *ctx);
 196         void (*event_write)(struct lib_ring_buffer_ctx *ctx, const void *src,
 197                             size_t len);
 198         /*
 199          * packet_avail_size returns the available size in the current
 200          * packet. Note that the size returned is only a hint, since it
 201          * may change due to concurrent writes.
 202          */
 203         size_t (*packet_avail_size)(struct channel *chan);
 204         wait_queue_head_t *(*get_reader_wait_queue)(struct ltt_channel *chan);
 205 };
 206
 207 struct ltt_channel {
 208         unsigned int id;
 209         struct channel *chan;           /* Channel buffers */
 210         struct lttng_ctx *ctx;
 211         /* Event ID management */
 212         struct ltt_session *session;
 213         struct file *file;              /* File associated to channel */
 214         unsigned int free_event_id;     /* Next event ID to allocate */
 215         struct list_head list;          /* Channel list */
 216         wait_queue_head_t notify_wait;  /* Channel addition notif. waitqueue */
 217         struct ltt_channel_ops *ops;
 218         int header_type;                /* 0: unset, 1: compact, 2: large */
 219         int metadata_dumped:1;
 220 };
 221
 222 struct ltt_session {
 223         int active;                     /* Is trace session active ? */
 224         int been_active;                /* Has trace session been active ? */
 225         struct file *file;              /* File associated to session */
 226         struct ltt_channel *metadata;   /* Metadata channel */
 227         struct list_head chan;          /* Channel list head */
 228         struct list_head events;        /* Event list head */
 229         struct list_head list;          /* Session list */
 230         unsigned int free_chan_id;      /* Next chan ID to allocate */
 231         uuid_le uuid;                   /* Trace session unique ID */
 232         int metadata_dumped:1;
 233 };
 234
 235 struct ltt_transport {
 236         char *name;
 237         struct module *owner;
 238         struct list_head node;
 239         struct ltt_channel_ops ops;
 240 };
 241
 242 struct ltt_session *ltt_session_create(void);
 243 int ltt_session_start(struct ltt_session *session);
 244 int ltt_session_stop(struct ltt_session *session);
 245 void ltt_session_destroy(struct ltt_session *session);
 246
 247 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 248                                        const char *transport_name,
 249                                        void *buf_addr,
 250                                        size_t subbuf_size, size_t num_subbuf,
 251                                        unsigned int switch_timer_interval,
 252                                        unsigned int read_timer_interval);
 253 struct ltt_channel *ltt_global_channel_create(struct ltt_session *session,
 254                                        int overwrite, void *buf_addr,
 255                                        size_t subbuf_size, size_t num_subbuf,
 256                                        unsigned int switch_timer_interval,
 257                                        unsigned int read_timer_interval);
 258
 259 struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 260                                    struct lttng_kernel_event *event_param,
 261                                    void *filter);
 262
 263 void ltt_transport_register(struct ltt_transport *transport);
 264 void ltt_transport_unregister(struct ltt_transport *transport);
 265
 266 int ltt_debugfs_abi_init(void);
 267 void ltt_debugfs_abi_exit(void);
 268
 269 int ltt_probe_register(struct lttng_probe_desc *desc);
 270 void ltt_probe_unregister(struct lttng_probe_desc *desc);
 271 const struct lttng_event_desc *ltt_event_get(const char *name);
 272 void ltt_event_put(const struct lttng_event_desc *desc);
 273 int ltt_probes_init(void);
 274 void ltt_probes_exit(void);
 275 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx);
 276 void lttng_destroy_context(struct lttng_ctx *ctx);
 277 int lttng_add_pid_to_ctx(struct lttng_ctx **ctx);
 278 int lttng_add_comm_to_ctx(struct lttng_ctx **ctx);
 279 int lttng_add_prio_to_ctx(struct lttng_ctx **ctx);
 280 int lttng_add_nice_to_ctx(struct lttng_ctx **ctx);
 281 int lttng_add_perf_counter_to_ctx(uint32_t type,
 282                                   uint64_t config,
 283                                   const char *name,
 284                                   struct lttng_ctx **ctx);
 285
 286 #ifdef CONFIG_KPROBES
 287 int lttng_kprobes_register(const char *name,
 288                 const char *symbol_name,
 289                 uint64_t offset,
 290                 uint64_t addr,
 291                 struct ltt_event *event);
 292 void lttng_kprobes_unregister(struct ltt_event *event);
 293 void lttng_kprobes_destroy_private(struct ltt_event *event);
 294 #else
 295 static inline
 296 int lttng_kprobes_register(const char *name,
 297                 const char *symbol_name,
 298                 uint64_t offset,
 299                 uint64_t addr,
 300                 struct ltt_event *event)
 301 {
 302         return -ENOSYS;
 303 }
 304
 305 static inline
 306 void lttng_kprobes_unregister(struct ltt_event *event)
 307 {
 308 }
 309
 310 static inline
 311 void lttng_kprobes_destroy_private(struct ltt_event *event)
 312 {
 313 }
 314 #endif
 315
 316 #ifdef CONFIG_DYNAMIC_FTRACE
 317 int lttng_ftrace_register(const char *name,
 318                           const char *symbol_name,
 319                           struct ltt_event *event);
 320 void lttng_ftrace_unregister(struct ltt_event *event);
 321 void lttng_ftrace_destroy_private(struct ltt_event *event);
 322 #else
 323 static inline
 324 int lttng_ftrace_register(const char *name,
 325                           const char *symbol_name,
 326                           struct ltt_event *event)
 327 {
 328         return -ENOSYS;
 329 }
 330
 331 static inline
 332 void lttng_ftrace_unregister(struct ltt_event *event)
 333 {
 334 }
 335
 336 static inline
 337 void lttng_ftrace_destroy_private(struct ltt_event *event)
 338 {
 339 }
 340 #endif
 341
 342 extern const struct file_operations lttng_tracepoint_list_fops;
 343
 344 #endif /* _LTT_EVENTS_H */