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