| 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 <ust-events-internal.h> |
| 14 | #include "ust-bitfield.h" |
| 15 | #include "ust-compat.h" |
| 16 | #include "lttng-tracer.h" |
| 17 | #include "../libringbuffer/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_lib_ring_buffer_config client_config; |
| 39 | |
| 40 | /* No nested use supported for metadata ring buffer. */ |
| 41 | static DEFINE_URCU_TLS(struct lttng_ust_lib_ring_buffer_ctx_private, private_ctx); |
| 42 | |
| 43 | static inline uint64_t lib_ring_buffer_clock_read( |
| 44 | struct lttng_ust_lib_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_lib_ring_buffer_config *config __attribute__((unused)), |
| 52 | struct lttng_ust_lib_ring_buffer_channel *chan __attribute__((unused)), |
| 53 | size_t offset __attribute__((unused)), |
| 54 | size_t *pre_header_padding __attribute__((unused)), |
| 55 | struct lttng_ust_lib_ring_buffer_ctx *ctx __attribute__((unused)), |
| 56 | void *client_ctx __attribute__((unused))) |
| 57 | { |
| 58 | return 0; |
| 59 | } |
| 60 | |
| 61 | #include "../libringbuffer/api.h" |
| 62 | #include "lttng-rb-clients.h" |
| 63 | |
| 64 | static uint64_t client_ring_buffer_clock_read( |
| 65 | struct lttng_ust_lib_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_lib_ring_buffer_config *config __attribute__((unused)), |
| 73 | struct lttng_ust_lib_ring_buffer_channel *chan __attribute__((unused)), |
| 74 | size_t offset __attribute__((unused)), |
| 75 | size_t *pre_header_padding __attribute__((unused)), |
| 76 | struct lttng_ust_lib_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_lib_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_lib_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_lib_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_lib_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_lib_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_lib_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_lib_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_lib_ring_buffer_ctx *ctx) |
| 259 | { |
| 260 | int ret; |
| 261 | |
| 262 | memset(&URCU_TLS(private_ctx), 0, sizeof(struct lttng_ust_lib_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_lib_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_lib_ring_buffer_ctx *ctx, |
| 283 | const void *src, size_t len, size_t alignment) |
| 284 | { |
| 285 | lttng_ust_lib_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_lib_ring_buffer_channel *rb_chan = chan->priv->rb_chan; |
| 293 | unsigned long o_begin; |
| 294 | struct lttng_ust_lib_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_lib_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_lib_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_lib_ring_buffer_channel *rb_chan = chan->priv->rb_chan; |
| 326 | struct lttng_ust_lib_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_COMPOUND_LITERAL(struct lttng_ust_channel_buffer_ops_private, { |
| 344 | .pub = <tng_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(<tng_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(<tng_relay_transport); |
| 371 | } |