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
  12 #include <linux/list.h>
  13 #include <linux/uuid.h>
  14 #include <linux/kprobes.h>
  15 #include "ltt-debugfs-abi.h"
  16
  17 #undef is_signed_type
  18 #define is_signed_type(type)            (((type)(-1)) < 0)
  19
  20 struct ltt_channel;
  21 struct ltt_session;
  22 struct lib_ring_buffer_ctx;
  23 struct perf_event;
  24 struct perf_event_attr;
  25
  26 /* Type description */
  27
  28 /* Update the astract_types name table in lttng-types.c along with this enum */
  29 enum abstract_types {
  30         atype_integer,
  31         atype_enum,
  32         atype_array,
  33         atype_sequence,
  34         atype_string,
  35         NR_ABSTRACT_TYPES,
  36 };
  37
  38 /* Update the string_encodings name table in lttng-types.c along with this enum */
  39 enum lttng_string_encodings {
  40         lttng_encode_none = 0,
  41         lttng_encode_UTF8 = 1,
  42         lttng_encode_ASCII = 2,
  43         NR_STRING_ENCODINGS,
  44 };
  45
  46 struct lttng_enum_entry {
  47         unsigned long long start, end;  /* start and end are inclusive */
  48         const char *string;
  49 };
  50
  51 #define __type_integer(_type, _byte_order, _base, _encoding)    \
  52         {                                                       \
  53             .atype = atype_integer,                             \
  54             .u.basic.integer =                                  \
  55                 {                                               \
  56                   .size = sizeof(_type) * CHAR_BIT,             \
  57                   .alignment = ltt_alignof(_type) * CHAR_BIT,   \
  58                   .signedness = is_signed_type(_type),          \
  59                   .reverse_byte_order = _byte_order != __BYTE_ORDER,    \
  60                   .base = _base,                                \
  61                   .encoding = lttng_encode_##_encoding,         \
  62                 },                                              \
  63         }                                                       \
  64
  65 struct lttng_integer_type {
  66         unsigned int size;              /* in bits */
  67         unsigned short alignment;       /* in bits */
  68         unsigned int signedness:1;
  69         unsigned int reverse_byte_order:1;
  70         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
  71         enum lttng_string_encodings encoding;
  72 };
  73
  74 union _lttng_basic_type {
  75         struct lttng_integer_type integer;
  76         struct {
  77                 const char *name;
  78         } enumeration;
  79         struct {
  80                 enum lttng_string_encodings encoding;
  81         } string;
  82 };
  83
  84 struct lttng_basic_type {
  85         enum abstract_types atype;
  86         union {
  87                 union _lttng_basic_type basic;
  88         } u;
  89 };
  90
  91 struct lttng_type {
  92         enum abstract_types atype;
  93         union {
  94                 union _lttng_basic_type basic;
  95                 struct {
  96                         struct lttng_basic_type elem_type;
  97                         unsigned int length;            /* num. elems. */
  98                 } array;
  99                 struct {
 100                         struct lttng_basic_type length_type;
 101                         struct lttng_basic_type elem_type;
 102                 } sequence;
 103         } u;
 104 };
 105
 106 struct lttng_enum {
 107         const char *name;
 108         struct lttng_type container_type;
 109         const struct lttng_enum_entry *entries;
 110         unsigned int len;
 111 };
 112
 113 /* Event field description */
 114
 115 struct lttng_event_field {
 116         const char *name;
 117         struct lttng_type type;
 118 };
 119
 120 struct lttng_ctx_field {
 121         const char *name;
 122         struct lttng_type type;
 123         void *callback;
 124         union {
 125                 struct {
 126                         struct perf_event **e;  /* per-cpu array */
 127                         struct list_head head;
 128                         struct perf_event_attr *attr;
 129                 } perf_counter;
 130         } u;
 131         void (*destroy)(struct lttng_ctx_field *field);
 132 };
 133
 134 struct lttng_ctx {
 135         struct lttng_ctx_field *fields;
 136         unsigned int nr_fields;
 137         unsigned int allocated_fields;
 138 };
 139
 140 struct lttng_event_desc {
 141         const char *name;
 142         void *probe_callback;
 143         const struct lttng_event_ctx *ctx;      /* context */
 144         const struct lttng_event_field *fields; /* event payload */
 145         unsigned int nr_fields;
 146         struct module *owner;
 147 };
 148
 149 struct lttng_probe_desc {
 150         const struct lttng_event_desc *event_desc;
 151         unsigned int nr_events;
 152         struct list_head head;                  /* chain registered probes */
 153 };
 154
 155 /*
 156  * ltt_event structure is referred to by the tracing fast path. It must be
 157  * kept small.
 158  */
 159 struct ltt_event {
 160         unsigned int id;
 161         struct ltt_channel *chan;
 162         const struct lttng_event_desc *desc;
 163         void *filter;
 164         enum lttng_kernel_instrumentation instrumentation;
 165         union {
 166                 struct {
 167                         struct kprobe kp;
 168                         char *symbol_name;
 169                 } kprobe;
 170                 struct {
 171                         char *symbol_name;
 172                 } ftrace;
 173         } u;
 174         struct list_head list;          /* Event list */
 175         int metadata_dumped:1;
 176 };
 177
 178 struct ltt_channel_ops {
 179         struct channel *(*channel_create)(const char *name,
 180                                 struct ltt_channel *ltt_chan,
 181                                 void *buf_addr,
 182                                 size_t subbuf_size, size_t num_subbuf,
 183                                 unsigned int switch_timer_interval,
 184                                 unsigned int read_timer_interval);
 185         void (*channel_destroy)(struct channel *chan);
 186         struct lib_ring_buffer *(*buffer_read_open)(struct channel *chan);
 187         void (*buffer_read_close)(struct lib_ring_buffer *buf);
 188         int (*event_reserve)(struct lib_ring_buffer_ctx *ctx,
 189                              uint32_t event_id);
 190         void (*event_commit)(struct lib_ring_buffer_ctx *ctx);
 191         void (*event_write)(struct lib_ring_buffer_ctx *ctx, const void *src,
 192                             size_t len);
 193         /*
 194          * packet_avail_size returns the available size in the current
 195          * packet. Note that the size returned is only a hint, since it
 196          * may change due to concurrent writes.
 197          */
 198         size_t (*packet_avail_size)(struct channel *chan);
 199         wait_queue_head_t *(*get_reader_wait_queue)(struct ltt_channel *chan);
 200 };
 201
 202 struct ltt_channel {
 203         unsigned int id;
 204         struct channel *chan;           /* Channel buffers */
 205         /* Event ID management */
 206         struct ltt_session *session;
 207         struct file *file;              /* File associated to channel */
 208         unsigned int free_event_id;     /* Next event ID to allocate */
 209         struct list_head list;          /* Channel list */
 210         wait_queue_head_t notify_wait;  /* Channel addition notif. waitqueue */
 211         struct ltt_channel_ops *ops;
 212         int header_type;                /* 0: unset, 1: compact, 2: large */
 213         int metadata_dumped:1;
 214 };
 215
 216 struct ltt_session {
 217         int active;                     /* Is trace session active ? */
 218         struct file *file;              /* File associated to session */
 219         struct ltt_channel *metadata;   /* Metadata channel */
 220         struct list_head chan;          /* Channel list head */
 221         struct list_head events;        /* Event list head */
 222         struct list_head list;          /* Session list */
 223         unsigned int free_chan_id;      /* Next chan ID to allocate */
 224         uuid_le uuid;                   /* Trace session unique ID */
 225         int metadata_dumped:1;
 226 };
 227
 228 struct ltt_transport {
 229         char *name;
 230         struct module *owner;
 231         struct list_head node;
 232         struct ltt_channel_ops ops;
 233 };
 234
 235 struct ltt_session *ltt_session_create(void);
 236 int ltt_session_start(struct ltt_session *session);
 237 int ltt_session_stop(struct ltt_session *session);
 238 void ltt_session_destroy(struct ltt_session *session);
 239
 240 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 241                                        const char *transport_name,
 242                                        void *buf_addr,
 243                                        size_t subbuf_size, size_t num_subbuf,
 244                                        unsigned int switch_timer_interval,
 245                                        unsigned int read_timer_interval);
 246 struct ltt_channel *ltt_global_channel_create(struct ltt_session *session,
 247                                        int overwrite, void *buf_addr,
 248                                        size_t subbuf_size, size_t num_subbuf,
 249                                        unsigned int switch_timer_interval,
 250                                        unsigned int read_timer_interval);
 251
 252 struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 253                                    struct lttng_kernel_event *event_param,
 254                                    void *filter);
 255
 256 void ltt_transport_register(struct ltt_transport *transport);
 257 void ltt_transport_unregister(struct ltt_transport *transport);
 258
 259 int ltt_debugfs_abi_init(void);
 260 void ltt_debugfs_abi_exit(void);
 261
 262 int ltt_probe_register(struct lttng_probe_desc *desc);
 263 void ltt_probe_unregister(struct lttng_probe_desc *desc);
 264 const struct lttng_event_desc *ltt_event_get(const char *name);
 265 void ltt_event_put(const struct lttng_event_desc *desc);
 266 int ltt_probes_init(void);
 267 void ltt_probes_exit(void);
 268 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx);
 269 void lttng_destroy_context(struct lttng_ctx *ctx);
 270
 271 #ifdef CONFIG_KPROBES
 272 int lttng_kprobes_register(const char *name,
 273                 const char *symbol_name,
 274                 uint64_t offset,
 275                 uint64_t addr,
 276                 struct ltt_event *event);
 277 void lttng_kprobes_unregister(struct ltt_event *event);
 278 void lttng_kprobes_destroy_private(struct ltt_event *event);
 279 #else
 280 static inline
 281 int lttng_kprobes_register(const char *name,
 282                 const char *symbol_name,
 283                 uint64_t offset,
 284                 uint64_t addr,
 285                 struct ltt_event *event)
 286 {
 287         return -ENOSYS;
 288 }
 289
 290 static inline
 291 void lttng_kprobes_unregister(struct ltt_event *event)
 292 {
 293 }
 294
 295 static inline
 296 void lttng_kprobes_destroy_private(struct ltt_event *event)
 297 {
 298 }
 299 #endif
 300
 301 #ifdef CONFIG_DYNAMIC_FTRACE
 302 int lttng_ftrace_register(const char *name,
 303                           const char *symbol_name,
 304                           struct ltt_event *event);
 305 void lttng_ftrace_unregister(struct ltt_event *event);
 306 void lttng_ftrace_destroy_private(struct ltt_event *event);
 307 #else
 308 static inline
 309 int lttng_ftrace_register(const char *name,
 310                           const char *symbol_name,
 311                           struct ltt_event *event)
 312 {
 313         return -ENOSYS;
 314 }
 315
 316 static inline
 317 void lttng_ftrace_unregister(struct ltt_event *event)
 318 {
 319 }
 320
 321 static inline
 322 void lttng_ftrace_destroy_private(struct ltt_event *event)
 323 {
 324 }
 325 #endif
 326
 327 extern const struct file_operations lttng_tracepoint_list_fops;
 328
 329 #endif /* _LTT_EVENTS_H */