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 notifier_block nb;
 132                         int hp_enable;
 133                         struct perf_event_attr *attr;
 134                 } perf_counter;
 135         } u;
 136         void (*destroy)(struct lttng_ctx_field *field);
 137 };
 138
 139 struct lttng_ctx {
 140         struct lttng_ctx_field *fields;
 141         unsigned int nr_fields;
 142         unsigned int allocated_fields;
 143 };
 144
 145 struct lttng_event_desc {
 146         const char *name;
 147         void *probe_callback;
 148         const struct lttng_event_ctx *ctx;      /* context */
 149         const struct lttng_event_field *fields; /* event payload */
 150         unsigned int nr_fields;
 151         struct module *owner;
 152 };
 153
 154 struct lttng_probe_desc {
 155         const struct lttng_event_desc *event_desc;
 156         unsigned int nr_events;
 157         struct list_head head;                  /* chain registered probes */
 158 };
 159
 160 /*
 161  * ltt_event structure is referred to by the tracing fast path. It must be
 162  * kept small.
 163  */
 164 struct ltt_event {
 165         unsigned int id;
 166         struct ltt_channel *chan;
 167         const struct lttng_event_desc *desc;
 168         void *filter;
 169         struct lttng_ctx *ctx;
 170         enum lttng_kernel_instrumentation instrumentation;
 171         union {
 172                 struct {
 173                         struct kprobe kp;
 174                         char *symbol_name;
 175                 } kprobe;
 176                 struct {
 177                         char *symbol_name;
 178                 } ftrace;
 179         } u;
 180         struct list_head list;          /* Event list */
 181         int metadata_dumped:1;
 182 };
 183
 184 struct ltt_channel_ops {
 185         struct channel *(*channel_create)(const char *name,
 186                                 struct ltt_channel *ltt_chan,
 187                                 void *buf_addr,
 188                                 size_t subbuf_size, size_t num_subbuf,
 189                                 unsigned int switch_timer_interval,
 190                                 unsigned int read_timer_interval);
 191         void (*channel_destroy)(struct channel *chan);
 192         struct lib_ring_buffer *(*buffer_read_open)(struct channel *chan);
 193         void (*buffer_read_close)(struct lib_ring_buffer *buf);
 194         int (*event_reserve)(struct lib_ring_buffer_ctx *ctx,
 195                              uint32_t event_id);
 196         void (*event_commit)(struct lib_ring_buffer_ctx *ctx);
 197         void (*event_write)(struct lib_ring_buffer_ctx *ctx, const void *src,
 198                             size_t len);
 199         /*
 200          * packet_avail_size returns the available size in the current
 201          * packet. Note that the size returned is only a hint, since it
 202          * may change due to concurrent writes.
 203          */
 204         size_t (*packet_avail_size)(struct channel *chan);
 205         wait_queue_head_t *(*get_reader_wait_queue)(struct ltt_channel *chan);
 206 };
 207
 208 struct ltt_channel {
 209         unsigned int id;
 210         struct channel *chan;           /* Channel buffers */
 211         struct lttng_ctx *ctx;
 212         /* Event ID management */
 213         struct ltt_session *session;
 214         struct file *file;              /* File associated to channel */
 215         unsigned int free_event_id;     /* Next event ID to allocate */
 216         struct list_head list;          /* Channel list */
 217         wait_queue_head_t notify_wait;  /* Channel addition notif. waitqueue */
 218         struct ltt_channel_ops *ops;
 219         int header_type;                /* 0: unset, 1: compact, 2: large */
 220         int metadata_dumped:1;
 221 };
 222
 223 struct ltt_session {
 224         int active;                     /* Is trace session active ? */
 225         int been_active;                /* Has trace session been active ? */
 226         struct file *file;              /* File associated to session */
 227         struct ltt_channel *metadata;   /* Metadata channel */
 228         struct list_head chan;          /* Channel list head */
 229         struct list_head events;        /* Event list head */
 230         struct list_head list;          /* Session list */
 231         unsigned int free_chan_id;      /* Next chan ID to allocate */
 232         uuid_le uuid;                   /* Trace session unique ID */
 233         int metadata_dumped:1;
 234 };
 235
 236 struct ltt_transport {
 237         char *name;
 238         struct module *owner;
 239         struct list_head node;
 240         struct ltt_channel_ops ops;
 241 };
 242
 243 struct ltt_session *ltt_session_create(void);
 244 int ltt_session_start(struct ltt_session *session);
 245 int ltt_session_stop(struct ltt_session *session);
 246 void ltt_session_destroy(struct ltt_session *session);
 247
 248 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 249                                        const char *transport_name,
 250                                        void *buf_addr,
 251                                        size_t subbuf_size, size_t num_subbuf,
 252                                        unsigned int switch_timer_interval,
 253                                        unsigned int read_timer_interval);
 254 struct ltt_channel *ltt_global_channel_create(struct ltt_session *session,
 255                                        int overwrite, void *buf_addr,
 256                                        size_t subbuf_size, size_t num_subbuf,
 257                                        unsigned int switch_timer_interval,
 258                                        unsigned int read_timer_interval);
 259
 260 struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 261                                    struct lttng_kernel_event *event_param,
 262                                    void *filter);
 263
 264 void ltt_transport_register(struct ltt_transport *transport);
 265 void ltt_transport_unregister(struct ltt_transport *transport);
 266
 267 int ltt_debugfs_abi_init(void);
 268 void ltt_debugfs_abi_exit(void);
 269
 270 int ltt_probe_register(struct lttng_probe_desc *desc);
 271 void ltt_probe_unregister(struct lttng_probe_desc *desc);
 272 const struct lttng_event_desc *ltt_event_get(const char *name);
 273 void ltt_event_put(const struct lttng_event_desc *desc);
 274 int ltt_probes_init(void);
 275 void ltt_probes_exit(void);
 276 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx);
 277 void lttng_remove_context_field(struct lttng_ctx **ctx,
 278                                 struct lttng_ctx_field *field);
 279 void lttng_destroy_context(struct lttng_ctx *ctx);
 280 int lttng_add_pid_to_ctx(struct lttng_ctx **ctx);
 281 int lttng_add_comm_to_ctx(struct lttng_ctx **ctx);
 282 int lttng_add_prio_to_ctx(struct lttng_ctx **ctx);
 283 int lttng_add_nice_to_ctx(struct lttng_ctx **ctx);
 284 int lttng_add_perf_counter_to_ctx(uint32_t type,
 285                                   uint64_t config,
 286                                   const char *name,
 287                                   struct lttng_ctx **ctx);
 288
 289 #ifdef CONFIG_KPROBES
 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 void lttng_kprobes_unregister(struct ltt_event *event);
 296 void lttng_kprobes_destroy_private(struct ltt_event *event);
 297 #else
 298 static inline
 299 int lttng_kprobes_register(const char *name,
 300                 const char *symbol_name,
 301                 uint64_t offset,
 302                 uint64_t addr,
 303                 struct ltt_event *event)
 304 {
 305         return -ENOSYS;
 306 }
 307
 308 static inline
 309 void lttng_kprobes_unregister(struct ltt_event *event)
 310 {
 311 }
 312
 313 static inline
 314 void lttng_kprobes_destroy_private(struct ltt_event *event)
 315 {
 316 }
 317 #endif
 318
 319 #ifdef CONFIG_DYNAMIC_FTRACE
 320 int lttng_ftrace_register(const char *name,
 321                           const char *symbol_name,
 322                           struct ltt_event *event);
 323 void lttng_ftrace_unregister(struct ltt_event *event);
 324 void lttng_ftrace_destroy_private(struct ltt_event *event);
 325 #else
 326 static inline
 327 int lttng_ftrace_register(const char *name,
 328                           const char *symbol_name,
 329                           struct ltt_event *event)
 330 {
 331         return -ENOSYS;
 332 }
 333
 334 static inline
 335 void lttng_ftrace_unregister(struct ltt_event *event)
 336 {
 337 }
 338
 339 static inline
 340 void lttng_ftrace_destroy_private(struct ltt_event *event)
 341 {
 342 }
 343 #endif
 344
 345 extern const struct file_operations lttng_tracepoint_list_fops;
 346
 347 #endif /* _LTT_EVENTS_H */