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