src/lib/lttng-ust/lttng-ring-buffer-metadata-client-template.h

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * LTTng lib ring buffer client template.
   7  */
   8
   9 #include <limits.h>
  10 #include <stddef.h>
  11 #include <stdint.h>
  12
  13 #include "lib/lttng-ust/events.h"
  14 #include "common/bitfield.h"
  15 #include "common/align.h"
  16 #include "lttng-tracer.h"
  17 #include "common/ringbuffer/frontend_types.h"
  18 #include <urcu/tls-compat.h>
  19
  20 struct metadata_packet_header {
  21         uint32_t magic;                 /* 0x75D11D57 */
  22         uint8_t  uuid[LTTNG_UST_UUID_LEN]; /* Unique Universal Identifier */
  23         uint32_t checksum;              /* 0 if unused */
  24         uint32_t content_size;          /* in bits */
  25         uint32_t packet_size;           /* in bits */
  26         uint8_t  compression_scheme;    /* 0 if unused */
  27         uint8_t  encryption_scheme;     /* 0 if unused */
  28         uint8_t  checksum_scheme;       /* 0 if unused */
  29         uint8_t  major;                 /* CTF spec major version number */
  30         uint8_t  minor;                 /* CTF spec minor version number */
  31         uint8_t  header_end[0];
  32 };
  33
  34 struct metadata_record_header {
  35         uint8_t header_end[0];          /* End of header */
  36 };
  37
  38 static const struct lttng_ust_ring_buffer_config client_config;
  39
  40 /* No nested use supported for metadata ring buffer. */
  41 static DEFINE_URCU_TLS(struct lttng_ust_ring_buffer_ctx_private, private_ctx);
  42
  43 static inline uint64_t lib_ring_buffer_clock_read(
  44                 struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)))
  45 {
  46         return 0;
  47 }
  48
  49 static inline
  50 size_t record_header_size(
  51                 const struct lttng_ust_ring_buffer_config *config __attribute__((unused)),
  52                 struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)),
  53                 size_t offset __attribute__((unused)),
  54                 size_t *pre_header_padding __attribute__((unused)),
  55                 struct lttng_ust_ring_buffer_ctx *ctx __attribute__((unused)),
  56                 void *client_ctx __attribute__((unused)))
  57 {
  58         return 0;
  59 }
  60
  61 #include "common/ringbuffer/api.h"
  62 #include "lttng-rb-clients.h"
  63
  64 static uint64_t client_ring_buffer_clock_read(
  65                 struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)))
  66 {
  67         return 0;
  68 }
  69
  70 static
  71 size_t client_record_header_size(
  72                 const struct lttng_ust_ring_buffer_config *config __attribute__((unused)),
  73                 struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)),
  74                 size_t offset __attribute__((unused)),
  75                 size_t *pre_header_padding __attribute__((unused)),
  76                 struct lttng_ust_ring_buffer_ctx *ctx __attribute__((unused)),
  77                 void *client_ctx __attribute__((unused)))
  78 {
  79         return 0;
  80 }
  81
  82 /**
  83  * client_packet_header_size - called on buffer-switch to a new sub-buffer
  84  *
  85  * Return header size without padding after the structure. Don't use packed
  86  * structure because gcc generates inefficient code on some architectures
  87  * (powerpc, mips..)
  88  */
  89 static size_t client_packet_header_size(void)
  90 {
  91         return offsetof(struct metadata_packet_header, header_end);
  92 }
  93
  94 static void client_buffer_begin(struct lttng_ust_ring_buffer *buf,
  95                 uint64_t tsc __attribute__((unused)),
  96                 unsigned int subbuf_idx,
  97                 struct lttng_ust_shm_handle *handle)
  98 {
  99         struct lttng_ust_ring_buffer_channel *chan = shmp(handle, buf->backend.chan);
 100         struct metadata_packet_header *header =
 101                 (struct metadata_packet_header *)
 102                         lib_ring_buffer_offset_address(&buf->backend,
 103                                 subbuf_idx * chan->backend.subbuf_size,
 104                                 handle);
 105         struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(chan);
 106
 107         assert(header);
 108         if (!header)
 109                 return;
 110         header->magic = TSDL_MAGIC_NUMBER;
 111         memcpy(header->uuid, lttng_chan->priv->uuid, sizeof(lttng_chan->priv->uuid));
 112         header->checksum = 0;           /* 0 if unused */
 113         header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
 114         header->packet_size = 0xFFFFFFFF;  /* in bits, for debugging */
 115         header->compression_scheme = 0; /* 0 if unused */
 116         header->encryption_scheme = 0;  /* 0 if unused */
 117         header->checksum_scheme = 0;    /* 0 if unused */
 118         header->major = CTF_SPEC_MAJOR;
 119         header->minor = CTF_SPEC_MINOR;
 120 }
 121
 122 /*
 123  * offset is assumed to never be 0 here : never deliver a completely empty
 124  * subbuffer. data_size is between 1 and subbuf_size.
 125  */
 126 static void client_buffer_end(struct lttng_ust_ring_buffer *buf,
 127                 uint64_t tsc  __attribute__((unused)),
 128                 unsigned int subbuf_idx, unsigned long data_size,
 129                 struct lttng_ust_shm_handle *handle)
 130 {
 131         struct lttng_ust_ring_buffer_channel *chan = shmp(handle, buf->backend.chan);
 132         struct metadata_packet_header *header =
 133                 (struct metadata_packet_header *)
 134                         lib_ring_buffer_offset_address(&buf->backend,
 135                                 subbuf_idx * chan->backend.subbuf_size,
 136                                 handle);
 137         unsigned long records_lost = 0;
 138
 139         assert(header);
 140         if (!header)
 141                 return;
 142         header->content_size = data_size * CHAR_BIT;            /* in bits */
 143         header->packet_size = LTTNG_UST_PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
 144         /*
 145          * We do not care about the records lost count, because the metadata
 146          * channel waits and retry.
 147          */
 148         (void) lib_ring_buffer_get_records_lost_full(&client_config, buf);
 149         records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
 150         records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
 151         WARN_ON_ONCE(records_lost != 0);
 152 }
 153
 154 static int client_buffer_create(
 155                 struct lttng_ust_ring_buffer *buf __attribute__((unused)),
 156                 void *priv __attribute__((unused)),
 157                 int cpu __attribute__((unused)),
 158                 const char *name __attribute__((unused)),
 159                 struct lttng_ust_shm_handle *handle __attribute__((unused)))
 160 {
 161         return 0;
 162 }
 163
 164 static void client_buffer_finalize(
 165                 struct lttng_ust_ring_buffer *buf __attribute__((unused)),
 166                 void *priv __attribute__((unused)),
 167                 int cpu __attribute__((unused)),
 168                 struct lttng_ust_shm_handle *handle __attribute__((unused)))
 169 {
 170 }
 171
 172 static const
 173 struct lttng_ust_client_lib_ring_buffer_client_cb client_cb = {
 174         .parent = {
 175                 .ring_buffer_clock_read = client_ring_buffer_clock_read,
 176                 .record_header_size = client_record_header_size,
 177                 .subbuffer_header_size = client_packet_header_size,
 178                 .buffer_begin = client_buffer_begin,
 179                 .buffer_end = client_buffer_end,
 180                 .buffer_create = client_buffer_create,
 181                 .buffer_finalize = client_buffer_finalize,
 182         },
 183 };
 184
 185 static const struct lttng_ust_ring_buffer_config client_config = {
 186         .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
 187         .cb.record_header_size = client_record_header_size,
 188         .cb.subbuffer_header_size = client_packet_header_size,
 189         .cb.buffer_begin = client_buffer_begin,
 190         .cb.buffer_end = client_buffer_end,
 191         .cb.buffer_create = client_buffer_create,
 192         .cb.buffer_finalize = client_buffer_finalize,
 193
 194         .tsc_bits = 0,
 195         .alloc = RING_BUFFER_ALLOC_GLOBAL,
 196         .sync = RING_BUFFER_SYNC_GLOBAL,
 197         .mode = RING_BUFFER_MODE_TEMPLATE,
 198         .backend = RING_BUFFER_PAGE,
 199         .output = RING_BUFFER_MMAP,
 200         .oops = RING_BUFFER_OOPS_CONSISTENCY,
 201         .ipi = RING_BUFFER_NO_IPI_BARRIER,
 202         .wakeup = RING_BUFFER_WAKEUP_BY_WRITER,
 203         .client_type = LTTNG_CLIENT_TYPE,
 204
 205          .cb_ptr = &client_cb.parent,
 206 };
 207
 208 static
 209 struct lttng_ust_channel_buffer *_channel_create(const char *name,
 210                                 void *buf_addr,
 211                                 size_t subbuf_size, size_t num_subbuf,
 212                                 unsigned int switch_timer_interval,
 213                                 unsigned int read_timer_interval,
 214                                 unsigned char *uuid,
 215                                 uint32_t chan_id,
 216                                 const int *stream_fds, int nr_stream_fds,
 217                                 int64_t blocking_timeout)
 218 {
 219         struct lttng_ust_abi_channel_config chan_priv_init;
 220         struct lttng_ust_shm_handle *handle;
 221         struct lttng_ust_channel_buffer *lttng_chan_buf;
 222
 223         lttng_chan_buf = lttng_ust_alloc_channel_buffer();
 224         if (!lttng_chan_buf)
 225                 return NULL;
 226         memcpy(lttng_chan_buf->priv->uuid, uuid, LTTNG_UST_UUID_LEN);
 227         lttng_chan_buf->priv->id = chan_id;
 228
 229         memset(&chan_priv_init, 0, sizeof(chan_priv_init));
 230         memcpy(chan_priv_init.uuid, uuid, LTTNG_UST_UUID_LEN);
 231         chan_priv_init.id = chan_id;
 232
 233         handle = channel_create(&client_config, name,
 234                         __alignof__(struct lttng_ust_channel_buffer),
 235                         sizeof(struct lttng_ust_channel_buffer),
 236                         &chan_priv_init,
 237                         lttng_chan_buf, buf_addr, subbuf_size, num_subbuf,
 238                         switch_timer_interval, read_timer_interval,
 239                         stream_fds, nr_stream_fds, blocking_timeout);
 240         if (!handle)
 241                 goto error;
 242         lttng_chan_buf->priv->rb_chan = shmp(handle, handle->chan);
 243         return lttng_chan_buf;
 244
 245 error:
 246         lttng_ust_free_channel_common(lttng_chan_buf->parent);
 247         return NULL;
 248 }
 249
 250 static
 251 void lttng_channel_destroy(struct lttng_ust_channel_buffer *lttng_chan_buf)
 252 {
 253         channel_destroy(lttng_chan_buf->priv->rb_chan, lttng_chan_buf->priv->rb_chan->handle, 1);
 254         lttng_ust_free_channel_common(lttng_chan_buf->parent);
 255 }
 256
 257 static
 258 int lttng_event_reserve(struct lttng_ust_ring_buffer_ctx *ctx)
 259 {
 260         int ret;
 261
 262         memset(&URCU_TLS(private_ctx), 0, sizeof(struct lttng_ust_ring_buffer_ctx_private));
 263         URCU_TLS(private_ctx).pub = ctx;
 264         URCU_TLS(private_ctx).chan = ctx->client_priv;
 265         ctx->priv = &URCU_TLS(private_ctx);
 266         ret = lib_ring_buffer_reserve(&client_config, ctx, NULL);
 267         if (ret)
 268                 return ret;
 269         if (lib_ring_buffer_backend_get_pages(&client_config, ctx,
 270                         &ctx->priv->backend_pages))
 271                 return -EPERM;
 272         return 0;
 273 }
 274
 275 static
 276 void lttng_event_commit(struct lttng_ust_ring_buffer_ctx *ctx)
 277 {
 278         lib_ring_buffer_commit(&client_config, ctx);
 279 }
 280
 281 static
 282 void lttng_event_write(struct lttng_ust_ring_buffer_ctx *ctx,
 283                 const void *src, size_t len, size_t alignment)
 284 {
 285         lttng_ust_ring_buffer_align_ctx(ctx, alignment);
 286         lib_ring_buffer_write(&client_config, ctx, src, len);
 287 }
 288
 289 static
 290 size_t lttng_packet_avail_size(struct lttng_ust_channel_buffer *chan)
 291 {
 292         struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
 293         unsigned long o_begin;
 294         struct lttng_ust_ring_buffer *buf;
 295
 296         buf = shmp(rb_chan->handle, rb_chan->backend.buf[0].shmp);      /* Only for global buffer ! */
 297         o_begin = v_read(&client_config, &buf->offset);
 298         if (subbuf_offset(o_begin, rb_chan) != 0) {
 299                 return rb_chan->backend.subbuf_size - subbuf_offset(o_begin, rb_chan);
 300         } else {
 301                 return rb_chan->backend.subbuf_size - subbuf_offset(o_begin, rb_chan)
 302                         - sizeof(struct metadata_packet_header);
 303         }
 304 }
 305
 306 static
 307 int lttng_is_finalized(struct lttng_ust_channel_buffer *chan)
 308 {
 309         struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
 310
 311         return lib_ring_buffer_channel_is_finalized(rb_chan);
 312 }
 313
 314 static
 315 int lttng_is_disabled(struct lttng_ust_channel_buffer *chan)
 316 {
 317         struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
 318
 319         return lib_ring_buffer_channel_is_disabled(rb_chan);
 320 }
 321
 322 static
 323 int lttng_flush_buffer(struct lttng_ust_channel_buffer *chan)
 324 {
 325         struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
 326         struct lttng_ust_ring_buffer *buf;
 327         int shm_fd, wait_fd, wakeup_fd;
 328         uint64_t memory_map_size;
 329
 330         buf = channel_get_ring_buffer(&client_config, rb_chan,
 331                         0, rb_chan->handle, &shm_fd, &wait_fd, &wakeup_fd,
 332                         &memory_map_size);
 333         lib_ring_buffer_switch(&client_config, buf,
 334                         SWITCH_ACTIVE, rb_chan->handle);
 335         return 0;
 336 }
 337
 338 static struct lttng_transport lttng_relay_transport = {
 339         .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
 340         .ops = {
 341                 .struct_size = sizeof(struct lttng_ust_channel_buffer_ops),
 342
 343                 .priv = LTTNG_UST_COMPOUND_LITERAL(struct lttng_ust_channel_buffer_ops_private, {
 344                         .pub = &lttng_relay_transport.ops,
 345                         .channel_create = _channel_create,
 346                         .channel_destroy = lttng_channel_destroy,
 347                         .packet_avail_size = lttng_packet_avail_size,
 348                         .is_finalized = lttng_is_finalized,
 349                         .is_disabled = lttng_is_disabled,
 350                         .flush_buffer = lttng_flush_buffer,
 351                 }),
 352                 .event_reserve = lttng_event_reserve,
 353                 .event_commit = lttng_event_commit,
 354                 .event_write = lttng_event_write,
 355         },
 356         .client_config = &client_config,
 357 };
 358
 359 void RING_BUFFER_MODE_TEMPLATE_INIT(void)
 360 {
 361         DBG("LTT : ltt ring buffer client \"%s\" init\n",
 362                 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
 363         lttng_transport_register(&lttng_relay_transport);
 364 }
 365
 366 void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
 367 {
 368         DBG("LTT : ltt ring buffer client \"%s\" exit\n",
 369                 "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
 370         lttng_transport_unregister(&lttng_relay_transport);
 371 }