| 1 | /* |
| 2 | * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include "field.hpp" |
| 9 | #include "lttng-sessiond.hpp" |
| 10 | #include "notification-thread-commands.hpp" |
| 11 | #include "session.hpp" |
| 12 | #include "trace-class.hpp" |
| 13 | #include "tsdl-trace-class-visitor.hpp" |
| 14 | #include "ctf2-trace-class-visitor.hpp" |
| 15 | #include "ust-app.hpp" |
| 16 | #include "ust-field-convert.hpp" |
| 17 | #include "ust-registry.hpp" |
| 18 | |
| 19 | #include <common/compat/directory-handle.hpp> |
| 20 | #include <common/error.hpp> |
| 21 | #include <common/exception.hpp> |
| 22 | #include <common/format.hpp> |
| 23 | #include <common/hashtable/utils.hpp> |
| 24 | #include <common/macros.hpp> |
| 25 | #include <common/make-unique.hpp> |
| 26 | #include <common/pthread-lock.hpp> |
| 27 | #include <common/runas.hpp> |
| 28 | #include <common/time.hpp> |
| 29 | #include <common/urcu.hpp> |
| 30 | |
| 31 | #include <fcntl.h> |
| 32 | #include <functional> |
| 33 | #include <initializer_list> |
| 34 | #include <mutex> |
| 35 | #include <sstream> |
| 36 | #include <string> |
| 37 | |
| 38 | namespace ls = lttng::sessiond; |
| 39 | namespace lst = lttng::sessiond::trace; |
| 40 | namespace lsu = lttng::sessiond::ust; |
| 41 | |
| 42 | namespace { |
| 43 | lttng_uuid generate_uuid_or_throw() |
| 44 | { |
| 45 | lttng_uuid new_uuid; |
| 46 | |
| 47 | if (lttng_uuid_generate(new_uuid)) { |
| 48 | LTTNG_THROW_POSIX("Failed to generate UST uuid", errno); |
| 49 | } |
| 50 | |
| 51 | return new_uuid; |
| 52 | } |
| 53 | |
| 54 | int get_count_order(unsigned int count) |
| 55 | { |
| 56 | int order; |
| 57 | |
| 58 | order = lttng_fls(count) - 1; |
| 59 | if (count & (count - 1)) { |
| 60 | order++; |
| 61 | } |
| 62 | |
| 63 | LTTNG_ASSERT(order >= 0); |
| 64 | return order; |
| 65 | } |
| 66 | |
| 67 | void clear_metadata_file(int fd) |
| 68 | { |
| 69 | const auto lseek_ret = lseek(fd, 0, SEEK_SET); |
| 70 | if (lseek_ret < 0) { |
| 71 | LTTNG_THROW_POSIX("Failed to seek to the beginning of the metadata file while clearing it", errno); |
| 72 | } |
| 73 | |
| 74 | const auto ret = ftruncate(fd, 0); |
| 75 | if (ret < 0) { |
| 76 | LTTNG_THROW_POSIX("Failed to truncate the metadata file while clearing it", errno); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | /* |
| 81 | * Validate that the id has reached the maximum allowed or not. |
| 82 | */ |
| 83 | bool is_max_channel_id(uint32_t id) |
| 84 | { |
| 85 | return id == UINT32_MAX; |
| 86 | } |
| 87 | |
| 88 | void destroy_channel_rcu(struct rcu_head *head) |
| 89 | { |
| 90 | DIAGNOSTIC_PUSH |
| 91 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 92 | lsu::registry_channel *chan = |
| 93 | lttng::utils::container_of(head, &lsu::registry_channel::_rcu_head); |
| 94 | DIAGNOSTIC_POP |
| 95 | |
| 96 | delete chan; |
| 97 | } |
| 98 | |
| 99 | /* |
| 100 | * Destroy every element of the registry and free the memory. This does NOT |
| 101 | * free the registry pointer since it might not have been allocated before so |
| 102 | * it's the caller responsability. |
| 103 | * |
| 104 | * Called from ~registry_session(), must not throw. |
| 105 | */ |
| 106 | void destroy_channel(lsu::registry_channel *chan, bool notify) noexcept |
| 107 | { |
| 108 | struct lttng_ht_iter iter; |
| 109 | lttng::sessiond::ust::registry_event *event; |
| 110 | enum lttng_error_code cmd_ret; |
| 111 | |
| 112 | LTTNG_ASSERT(chan); |
| 113 | |
| 114 | if (notify) { |
| 115 | cmd_ret = notification_thread_command_remove_channel( |
| 116 | the_notification_thread_handle, |
| 117 | chan->_consumer_key, LTTNG_DOMAIN_UST); |
| 118 | if (cmd_ret != LTTNG_OK) { |
| 119 | ERR("Failed to remove channel from notification thread"); |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | if (chan->_events) { |
| 124 | lttng::urcu::read_lock_guard read_lock_guard; |
| 125 | |
| 126 | /* Destroy all event associated with this registry. */ |
| 127 | DIAGNOSTIC_PUSH |
| 128 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 129 | cds_lfht_for_each_entry( |
| 130 | chan->_events->ht, &iter.iter, event, _node) { |
| 131 | /* Delete the node from the ht and free it. */ |
| 132 | ust_registry_channel_destroy_event(chan, event); |
| 133 | } |
| 134 | DIAGNOSTIC_POP |
| 135 | } |
| 136 | |
| 137 | call_rcu(&chan->_rcu_head, destroy_channel_rcu); |
| 138 | } |
| 139 | |
| 140 | void destroy_enum(lsu::registry_enum *reg_enum) |
| 141 | { |
| 142 | if (!reg_enum) { |
| 143 | return; |
| 144 | } |
| 145 | |
| 146 | delete reg_enum; |
| 147 | } |
| 148 | |
| 149 | void destroy_enum_rcu(struct rcu_head *head) |
| 150 | { |
| 151 | DIAGNOSTIC_PUSH |
| 152 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 153 | lsu::registry_enum *reg_enum = |
| 154 | lttng::utils::container_of(head, &lsu::registry_enum::rcu_head); |
| 155 | DIAGNOSTIC_POP |
| 156 | |
| 157 | destroy_enum(reg_enum); |
| 158 | } |
| 159 | |
| 160 | /* |
| 161 | * Hash table match function for enumerations in the session. Match is |
| 162 | * performed on enumeration name, and confirmed by comparing the enum |
| 163 | * entries. |
| 164 | */ |
| 165 | int ht_match_enum(struct cds_lfht_node *node, const void *_key) |
| 166 | { |
| 167 | lsu::registry_enum *_enum; |
| 168 | const lsu::registry_enum *key; |
| 169 | |
| 170 | LTTNG_ASSERT(node); |
| 171 | LTTNG_ASSERT(_key); |
| 172 | |
| 173 | DIAGNOSTIC_PUSH |
| 174 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 175 | _enum = caa_container_of(node, lsu::registry_enum, |
| 176 | node.node); |
| 177 | DIAGNOSTIC_POP |
| 178 | |
| 179 | LTTNG_ASSERT(_enum); |
| 180 | key = (lsu::registry_enum *) _key; |
| 181 | |
| 182 | return *_enum == *key; |
| 183 | } |
| 184 | |
| 185 | /* |
| 186 | * Hash table match function for enumerations in the session. Match is |
| 187 | * performed by enumeration ID. |
| 188 | */ |
| 189 | int ht_match_enum_id(struct cds_lfht_node *node, const void *_key) |
| 190 | { |
| 191 | lsu::registry_enum *_enum; |
| 192 | const lsu::registry_enum *key = (lsu::registry_enum *) _key; |
| 193 | |
| 194 | LTTNG_ASSERT(node); |
| 195 | LTTNG_ASSERT(_key); |
| 196 | |
| 197 | DIAGNOSTIC_PUSH |
| 198 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 199 | _enum = caa_container_of(node, lsu::registry_enum, node.node); |
| 200 | DIAGNOSTIC_POP |
| 201 | |
| 202 | LTTNG_ASSERT(_enum); |
| 203 | |
| 204 | if (_enum->id != key->id) { |
| 205 | goto no_match; |
| 206 | } |
| 207 | |
| 208 | /* Match. */ |
| 209 | return 1; |
| 210 | |
| 211 | no_match: |
| 212 | return 0; |
| 213 | } |
| 214 | |
| 215 | /* |
| 216 | * Hash table hash function for enumerations in the session. The |
| 217 | * enumeration name is used for hashing. |
| 218 | */ |
| 219 | unsigned long ht_hash_enum(void *_key, unsigned long seed) |
| 220 | { |
| 221 | lsu::registry_enum *key = (lsu::registry_enum *) _key; |
| 222 | |
| 223 | LTTNG_ASSERT(key); |
| 224 | return hash_key_str(key->name.c_str(), seed); |
| 225 | } |
| 226 | } /* namespace */ |
| 227 | |
| 228 | void lsu::details::locked_registry_session_release(lsu::registry_session *session) |
| 229 | { |
| 230 | pthread_mutex_unlock(&session->_lock); |
| 231 | } |
| 232 | |
| 233 | lsu::registry_session::registry_session(const struct lst::abi& in_abi, |
| 234 | uint32_t major, |
| 235 | uint32_t minor, |
| 236 | const char *root_shm_path, |
| 237 | const char *shm_path, |
| 238 | uid_t euid, |
| 239 | gid_t egid, |
| 240 | uint64_t tracing_id) : |
| 241 | lst::trace_class(in_abi, generate_uuid_or_throw()), |
| 242 | _root_shm_path{root_shm_path ? root_shm_path : ""}, |
| 243 | _shm_path{shm_path ? shm_path : ""}, |
| 244 | _metadata_path{_shm_path.size() > 0 ? fmt::format("{}/metadata", _shm_path) : |
| 245 | std::string("")}, |
| 246 | _uid{euid}, |
| 247 | _gid{egid}, |
| 248 | _app_tracer_version{.major = major, .minor = minor}, |
| 249 | _tracing_id{tracing_id}, |
| 250 | _clock{lttng::make_unique<lsu::clock_class>()}, |
| 251 | _metadata_generating_visitor{lttng::make_unique<ls::tsdl::trace_class_visitor>( |
| 252 | abi, [this](const std::string& fragment) { |
| 253 | _append_metadata_fragment(fragment); |
| 254 | })}, |
| 255 | _packet_header{_create_packet_header()} |
| 256 | { |
| 257 | pthread_mutex_init(&_lock, NULL); |
| 258 | if (_shm_path.size() > 0) { |
| 259 | if (run_as_mkdir_recursive(_shm_path.c_str(), S_IRWXU | S_IRWXG, euid, egid)) { |
| 260 | LTTNG_THROW_POSIX("run_as_mkdir_recursive", errno); |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | if (_metadata_path.size() > 0) { |
| 265 | /* Create metadata file. */ |
| 266 | const int ret = run_as_open(_metadata_path.c_str(), O_WRONLY | O_CREAT | O_EXCL, |
| 267 | S_IRUSR | S_IWUSR, euid, egid); |
| 268 | if (ret < 0) { |
| 269 | LTTNG_THROW_POSIX(fmt::format("Failed to open metadata file during registry session creation: path = {}", |
| 270 | _metadata_path), errno); |
| 271 | } |
| 272 | |
| 273 | _metadata_fd = ret; |
| 274 | } |
| 275 | |
| 276 | _enums.reset(lttng_ht_new(0, LTTNG_HT_TYPE_STRING)); |
| 277 | if (!_enums) { |
| 278 | LTTNG_THROW_POSIX("Failed to create enums hash table", ENOMEM); |
| 279 | } |
| 280 | |
| 281 | /* hash/match functions are specified at call site. */ |
| 282 | _enums->match_fct = NULL; |
| 283 | _enums->hash_fct = NULL; |
| 284 | |
| 285 | _channels.reset(lttng_ht_new(0, LTTNG_HT_TYPE_U64)); |
| 286 | if (!_channels) { |
| 287 | LTTNG_THROW_POSIX("Failed to create channels hash table", ENOMEM); |
| 288 | } |
| 289 | } |
| 290 | |
| 291 | lst::type::cuptr lsu::registry_session::_create_packet_header() const |
| 292 | { |
| 293 | lst::structure_type::fields packet_header_fields; |
| 294 | |
| 295 | /* uint32_t magic */ |
| 296 | packet_header_fields.emplace_back(lttng::make_unique<lst::field>("magic", |
| 297 | lttng::make_unique<lst::integer_type>(abi.uint32_t_alignment, |
| 298 | abi.byte_order, 32, lst::integer_type::signedness::UNSIGNED, |
| 299 | lst::integer_type::base::HEXADECIMAL, |
| 300 | std::initializer_list<lst::integer_type::role>({lst::integer_type::role::PACKET_MAGIC_NUMBER})))); |
| 301 | |
| 302 | /* uuid */ |
| 303 | packet_header_fields.emplace_back(lttng::make_unique<lst::field>("uuid", |
| 304 | lttng::make_unique<lst::static_length_blob_type>(0, 16, |
| 305 | std::initializer_list<lst::static_length_blob_type::role>({lst::static_length_blob_type::role::METADATA_STREAM_UUID})))); |
| 306 | |
| 307 | /* uint32_t stream_id */ |
| 308 | packet_header_fields.emplace_back(lttng::make_unique<lst::field>("stream_id", |
| 309 | lttng::make_unique<lst::integer_type>(abi.uint32_t_alignment, |
| 310 | abi.byte_order, 32, lst::integer_type::signedness::UNSIGNED, |
| 311 | lst::integer_type::base::DECIMAL, |
| 312 | std::initializer_list<lst::integer_type::role>({lst::integer_type::role::DATA_STREAM_CLASS_ID})))); |
| 313 | |
| 314 | /* uint64_t stream_instance_id */ |
| 315 | packet_header_fields.emplace_back(lttng::make_unique<lst::field>("stream_instance_id", |
| 316 | lttng::make_unique<lst::integer_type>(abi.uint64_t_alignment, |
| 317 | abi.byte_order, 64, lst::integer_type::signedness::UNSIGNED, |
| 318 | lst::integer_type::base::DECIMAL, |
| 319 | std::initializer_list<lst::integer_type::role>({lst::integer_type::role::DATA_STREAM_ID})))); |
| 320 | |
| 321 | return lttng::make_unique<lst::structure_type>(0, std::move(packet_header_fields)); |
| 322 | } |
| 323 | |
| 324 | const lst::type *lsu::registry_session::get_packet_header() const noexcept |
| 325 | { |
| 326 | return _packet_header.get(); |
| 327 | } |
| 328 | |
| 329 | /* |
| 330 | * For a given enumeration in a registry, delete the entry and destroy |
| 331 | * the enumeration. |
| 332 | * |
| 333 | * Note that this is used by ~registry_session() and must not throw. |
| 334 | */ |
| 335 | void lsu::registry_session::_destroy_enum(lsu::registry_enum *reg_enum) noexcept |
| 336 | { |
| 337 | int ret; |
| 338 | lttng::urcu::read_lock_guard read_lock_guard; |
| 339 | |
| 340 | LTTNG_ASSERT(reg_enum); |
| 341 | ASSERT_RCU_READ_LOCKED(); |
| 342 | |
| 343 | /* Delete the node first. */ |
| 344 | struct lttng_ht_iter iter; |
| 345 | iter.iter.node = ®_enum->node.node; |
| 346 | ret = lttng_ht_del(_enums.get(), &iter); |
| 347 | LTTNG_ASSERT(!ret); |
| 348 | call_rcu(®_enum->rcu_head, destroy_enum_rcu); |
| 349 | } |
| 350 | |
| 351 | lsu::registry_session::~registry_session() |
| 352 | { |
| 353 | int ret; |
| 354 | struct lttng_ht_iter iter; |
| 355 | lsu::registry_channel *chan; |
| 356 | lsu::registry_enum *reg_enum; |
| 357 | |
| 358 | /* On error, EBUSY can be returned if lock. Code flow error. */ |
| 359 | ret = pthread_mutex_destroy(&_lock); |
| 360 | LTTNG_ASSERT(!ret); |
| 361 | |
| 362 | if (_channels) { |
| 363 | lttng::urcu::read_lock_guard read_lock_guard; |
| 364 | |
| 365 | /* Destroy all event associated with this registry. */ |
| 366 | DIAGNOSTIC_PUSH |
| 367 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 368 | cds_lfht_for_each_entry(_channels->ht, &iter.iter, chan, _node.node) { |
| 369 | /* Delete the node from the ht and free it. */ |
| 370 | ret = lttng_ht_del(_channels.get(), &iter); |
| 371 | LTTNG_ASSERT(!ret); |
| 372 | destroy_channel(chan, true); |
| 373 | } |
| 374 | DIAGNOSTIC_POP |
| 375 | } |
| 376 | |
| 377 | free(_metadata); |
| 378 | if (_metadata_fd >= 0) { |
| 379 | ret = close(_metadata_fd); |
| 380 | if (ret) { |
| 381 | PERROR("close"); |
| 382 | } |
| 383 | |
| 384 | ret = run_as_unlink(_metadata_path.c_str(), _uid, _gid); |
| 385 | if (ret) { |
| 386 | PERROR("unlink"); |
| 387 | } |
| 388 | } |
| 389 | |
| 390 | if (_root_shm_path[0]) { |
| 391 | /* Try to delete the directory hierarchy. */ |
| 392 | (void) run_as_rmdir_recursive(_root_shm_path.c_str(), _uid, _gid, |
| 393 | LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG); |
| 394 | } |
| 395 | |
| 396 | /* Destroy the enum hash table */ |
| 397 | if (_enums) { |
| 398 | lttng::urcu::read_lock_guard read_lock_guard; |
| 399 | |
| 400 | /* Destroy all enum entries associated with this registry. */ |
| 401 | DIAGNOSTIC_PUSH |
| 402 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 403 | cds_lfht_for_each_entry (_enums->ht, &iter.iter, reg_enum, node.node) { |
| 404 | _destroy_enum(reg_enum); |
| 405 | } |
| 406 | DIAGNOSTIC_POP |
| 407 | } |
| 408 | } |
| 409 | |
| 410 | lsu::registry_session::locked_ptr lsu::registry_session::lock() noexcept |
| 411 | { |
| 412 | pthread_mutex_lock(&_lock); |
| 413 | return locked_ptr(this); |
| 414 | } |
| 415 | |
| 416 | /* |
| 417 | * Initialize registry with default values. |
| 418 | */ |
| 419 | void lsu::registry_session::add_channel(uint64_t key) |
| 420 | { |
| 421 | lttng::pthread::lock_guard session_lock_guard(_lock); |
| 422 | |
| 423 | /* |
| 424 | * Assign a channel ID right now since the event notification comes |
| 425 | * *before* the channel notify so the ID needs to be set at this point so |
| 426 | * the metadata can be dumped for that event. |
| 427 | */ |
| 428 | if (is_max_channel_id(_used_channel_id)) { |
| 429 | LTTNG_THROW_ERROR(fmt::format("Failed to allocate unique id for channel under session while adding channel")); |
| 430 | } |
| 431 | |
| 432 | auto chan = new lsu::registry_channel( |
| 433 | _get_next_channel_id(), abi, _clock->name, |
| 434 | /* Registered channel listener. */ |
| 435 | [this](const lsu::registry_channel& registered_channel) { |
| 436 | /* |
| 437 | * Channel registration completed, serialize it's layout's |
| 438 | * description. |
| 439 | */ |
| 440 | registered_channel.accept(*_metadata_generating_visitor); |
| 441 | }, |
| 442 | /* Added event listener. */ |
| 443 | [this](const lsu::registry_channel& channel, |
| 444 | const lsu::registry_event& added_event) { |
| 445 | /* |
| 446 | * The channel and its event classes will be dumped at once when |
| 447 | * it is registered. This check prevents event classes from being |
| 448 | * declared before their stream class. |
| 449 | */ |
| 450 | if (channel.is_registered()) { |
| 451 | added_event.accept(*_metadata_generating_visitor); |
| 452 | } |
| 453 | }); |
| 454 | |
| 455 | lttng::urcu::read_lock_guard rcu_read_lock_guard; |
| 456 | lttng_ht_node_init_u64(&chan->_node, key); |
| 457 | lttng_ht_add_unique_u64(_channels.get(), &chan->_node); |
| 458 | } |
| 459 | |
| 460 | lttng::sessiond::ust::registry_channel& lsu::registry_session::get_channel( |
| 461 | uint64_t channel_key) const |
| 462 | { |
| 463 | lttng::urcu::read_lock_guard read_lock_guard; |
| 464 | struct lttng_ht_node_u64 *node; |
| 465 | struct lttng_ht_iter iter; |
| 466 | |
| 467 | ASSERT_LOCKED(_lock); |
| 468 | |
| 469 | lttng_ht_lookup(_channels.get(), &channel_key, &iter); |
| 470 | node = lttng_ht_iter_get_node_u64(&iter); |
| 471 | if (!node) { |
| 472 | LTTNG_THROW_INVALID_ARGUMENT_ERROR(fmt::format( |
| 473 | "Invalid channel key provided: channel key = {}", channel_key)); |
| 474 | } |
| 475 | |
| 476 | DIAGNOSTIC_PUSH |
| 477 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 478 | auto chan = lttng::utils::container_of(node, &lsu::registry_channel::_node); |
| 479 | DIAGNOSTIC_POP |
| 480 | return *chan; |
| 481 | } |
| 482 | |
| 483 | void lsu::registry_session::remove_channel(uint64_t channel_key, bool notify) |
| 484 | { |
| 485 | struct lttng_ht_iter iter; |
| 486 | int ret; |
| 487 | lttng::urcu::read_lock_guard read_lock_guard; |
| 488 | |
| 489 | ASSERT_LOCKED(_lock); |
| 490 | auto& channel = get_channel(channel_key); |
| 491 | |
| 492 | iter.iter.node = &channel._node.node; |
| 493 | ret = lttng_ht_del(_channels.get(), &iter); |
| 494 | LTTNG_ASSERT(!ret); |
| 495 | destroy_channel(&channel, notify); |
| 496 | } |
| 497 | |
| 498 | void lsu::registry_session::accept( |
| 499 | lttng::sessiond::trace::trace_class_environment_visitor& visitor) const |
| 500 | { |
| 501 | ASSERT_LOCKED(_lock); |
| 502 | |
| 503 | visitor.visit(lst::environment_field<const char *>("domain", "ust")); |
| 504 | visitor.visit(lst::environment_field<const char *>("tracer_name", "lttng-ust")); |
| 505 | visitor.visit(lst::environment_field<int64_t>("tracer_major", _app_tracer_version.major)); |
| 506 | visitor.visit(lst::environment_field<int64_t>("tracer_minor", _app_tracer_version.minor)); |
| 507 | visitor.visit(lst::environment_field<const char *>("tracer_buffering_scheme", |
| 508 | get_buffering_scheme() == LTTNG_BUFFER_PER_PID ? "pid" : "uid")); |
| 509 | visitor.visit(lst::environment_field<int64_t>("architecture_bit_width", abi.bits_per_long)); |
| 510 | |
| 511 | { |
| 512 | /* The caller already holds the session and session list locks. */ |
| 513 | ASSERT_SESSION_LIST_LOCKED(); |
| 514 | const auto session = lttng::sessiond::find_session_by_id(_tracing_id); |
| 515 | |
| 516 | LTTNG_ASSERT(session); |
| 517 | ASSERT_LOCKED(session->lock); |
| 518 | |
| 519 | visitor.visit(lst::environment_field<const char *>("trace_name", |
| 520 | session->has_auto_generated_name ? DEFAULT_SESSION_NAME : |
| 521 | session->name)); |
| 522 | visitor.visit(lst::environment_field<std::string>("trace_creation_datetime", |
| 523 | lttng::utils::time_to_iso8601_str(session->creation_time))); |
| 524 | visitor.visit(lst::environment_field<const char *>("hostname", session->hostname)); |
| 525 | } |
| 526 | } |
| 527 | |
| 528 | void lsu::registry_session::_accept_on_clock_classes(lst::trace_class_visitor& visitor) const |
| 529 | { |
| 530 | ASSERT_LOCKED(_lock); |
| 531 | _clock->accept(visitor); |
| 532 | } |
| 533 | |
| 534 | void lsu::registry_session::_accept_on_stream_classes(lst::trace_class_visitor& visitor) const |
| 535 | { |
| 536 | ASSERT_LOCKED(_lock); |
| 537 | |
| 538 | std::vector<const lttng::sessiond::ust::registry_channel *> sorted_stream_classes; |
| 539 | |
| 540 | { |
| 541 | lttng::urcu::read_lock_guard rcu_lock_guard; |
| 542 | const lsu::registry_channel *channel; |
| 543 | lttng_ht_iter channel_it; |
| 544 | |
| 545 | DIAGNOSTIC_PUSH |
| 546 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 547 | cds_lfht_for_each_entry(_channels->ht, &channel_it.iter, channel, _node.node) { |
| 548 | sorted_stream_classes.emplace_back(channel); |
| 549 | } |
| 550 | DIAGNOSTIC_POP |
| 551 | } |
| 552 | |
| 553 | std::sort(sorted_stream_classes.begin(), sorted_stream_classes.end(), |
| 554 | [](const lttng::sessiond::ust::registry_channel *a, |
| 555 | const lttng::sessiond::ust::registry_channel *b) { |
| 556 | return a->id < b->id; |
| 557 | }); |
| 558 | |
| 559 | for (const auto stream_class : sorted_stream_classes) { |
| 560 | stream_class->accept(visitor); |
| 561 | } |
| 562 | } |
| 563 | |
| 564 | /* |
| 565 | * Return next available channel id and increment the used counter. The |
| 566 | * is_max_channel_id function MUST be called before in order to validate |
| 567 | * if the maximum number of IDs have been reached. If not, it is safe to call |
| 568 | * this function. |
| 569 | * |
| 570 | * Return a unique channel ID. If max is reached, the used_channel_id counter |
| 571 | * is returned. |
| 572 | */ |
| 573 | uint32_t lsu::registry_session::_get_next_channel_id() |
| 574 | { |
| 575 | if (is_max_channel_id(_used_channel_id)) { |
| 576 | return _used_channel_id; |
| 577 | } |
| 578 | |
| 579 | _used_channel_id++; |
| 580 | return _next_channel_id++; |
| 581 | } |
| 582 | |
| 583 | void lsu::registry_session::_increase_metadata_size(size_t reservation_length) |
| 584 | { |
| 585 | const auto new_len = _metadata_len + reservation_length; |
| 586 | auto new_alloc_len = new_len; |
| 587 | const auto old_alloc_len = _metadata_alloc_len; |
| 588 | |
| 589 | /* Rounding the new allocation length to the next power of 2 would overflow. */ |
| 590 | if (new_alloc_len > (UINT32_MAX >> 1)) { |
| 591 | LTTNG_THROW_ERROR("Failed to reserve trace metadata storage as the new size would overflow"); |
| 592 | } |
| 593 | |
| 594 | /* The current allocation length is already the largest we can afford. */ |
| 595 | if ((old_alloc_len << 1) > (UINT32_MAX >> 1)) { |
| 596 | LTTNG_THROW_ERROR("Failed to reserve trace metadata storage as the max size was already reached"); |
| 597 | } |
| 598 | |
| 599 | if (new_alloc_len > old_alloc_len) { |
| 600 | new_alloc_len = std::max<size_t>( |
| 601 | 1U << get_count_order(new_alloc_len), old_alloc_len << 1); |
| 602 | |
| 603 | auto newptr = (char *) realloc(_metadata, new_alloc_len); |
| 604 | if (!newptr) { |
| 605 | LTTNG_THROW_POSIX("Failed to allocate trace metadata storage", errno); |
| 606 | } |
| 607 | |
| 608 | _metadata = newptr; |
| 609 | |
| 610 | /* We zero directly the memory from start of allocation. */ |
| 611 | memset(&_metadata[old_alloc_len], 0, new_alloc_len - old_alloc_len); |
| 612 | _metadata_alloc_len = new_alloc_len; |
| 613 | } |
| 614 | |
| 615 | _metadata_len += reservation_length; |
| 616 | } |
| 617 | |
| 618 | void lsu::registry_session::_append_metadata_fragment(const std::string& fragment) |
| 619 | { |
| 620 | const auto offset = _metadata_len; |
| 621 | |
| 622 | _increase_metadata_size(fragment.size()); |
| 623 | memcpy(&_metadata[offset], fragment.c_str(), fragment.size()); |
| 624 | |
| 625 | if (_metadata_fd >= 0) { |
| 626 | const auto bytes_written = |
| 627 | lttng_write(_metadata_fd, fragment.c_str(), fragment.size()); |
| 628 | |
| 629 | if (bytes_written != fragment.size()) { |
| 630 | LTTNG_THROW_POSIX("Failed to write trace metadata fragment to file", |
| 631 | errno); |
| 632 | } |
| 633 | } |
| 634 | } |
| 635 | |
| 636 | void lsu::registry_session::_reset_metadata() |
| 637 | { |
| 638 | _metadata_len_sent = 0; |
| 639 | memset(_metadata, 0, _metadata_alloc_len); |
| 640 | _metadata_len = 0; |
| 641 | |
| 642 | if (_metadata_fd > 0) { |
| 643 | /* Clear the metadata file's content. */ |
| 644 | clear_metadata_file(_metadata_fd); |
| 645 | } |
| 646 | } |
| 647 | |
| 648 | void lsu::registry_session::_generate_metadata() |
| 649 | { |
| 650 | trace_class::accept(*_metadata_generating_visitor); |
| 651 | } |
| 652 | |
| 653 | void lsu::registry_session::regenerate_metadata() |
| 654 | { |
| 655 | lttng::pthread::lock_guard registry_lock(_lock); |
| 656 | |
| 657 | /* Resample the clock */ |
| 658 | _clock = lttng::make_unique<lsu::clock_class>(); |
| 659 | |
| 660 | _metadata_version++; |
| 661 | _reset_metadata(); |
| 662 | _generate_metadata(); |
| 663 | } |
| 664 | |
| 665 | /* |
| 666 | * Lookup enumeration by enum ID. |
| 667 | * |
| 668 | * Note that there is no need to lock the registry session as this only |
| 669 | * performs an RCU-protected look-up. The function also return an rcu-protected |
| 670 | * reference, which ensures that the caller keeps the RCU read lock until it |
| 671 | * disposes of the object. |
| 672 | */ |
| 673 | lsu::registry_enum::const_rcu_protected_reference |
| 674 | lsu::registry_session::get_enumeration(const char *enum_name, uint64_t enum_id) const |
| 675 | { |
| 676 | lsu::registry_enum *reg_enum = NULL; |
| 677 | struct lttng_ht_node_str *node; |
| 678 | struct lttng_ht_iter iter; |
| 679 | lttng::urcu::unique_read_lock rcu_lock; |
| 680 | /* |
| 681 | * Hack: only the name is used for hashing; the rest of the attributes |
| 682 | * can be fudged. |
| 683 | */ |
| 684 | lsu::registry_signed_enum reg_enum_lookup(enum_name, nullptr, 0); |
| 685 | |
| 686 | ASSERT_RCU_READ_LOCKED(); |
| 687 | |
| 688 | reg_enum_lookup.id = enum_id; |
| 689 | cds_lfht_lookup(_enums->ht, |
| 690 | ht_hash_enum((void *) ®_enum_lookup, lttng_ht_seed), |
| 691 | ht_match_enum_id, ®_enum_lookup, &iter.iter); |
| 692 | node = lttng_ht_iter_get_node_str(&iter); |
| 693 | if (!node) { |
| 694 | LTTNG_THROW_PROTOCOL_ERROR(fmt::format( |
| 695 | "Unknown enumeration referenced by application event field: enum name = `{}`, enum id = {}", |
| 696 | enum_name, enum_id)); |
| 697 | } |
| 698 | |
| 699 | DIAGNOSTIC_PUSH |
| 700 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 701 | reg_enum = lttng::utils::container_of(node, &lsu::registry_enum::node); |
| 702 | DIAGNOSTIC_POP |
| 703 | |
| 704 | return lsu::registry_enum::const_rcu_protected_reference{*reg_enum, std::move(rcu_lock)}; |
| 705 | } |
| 706 | |
| 707 | /* |
| 708 | * Lookup enumeration by name and comparing enumeration entries. |
| 709 | * Needs to be called from RCU read-side critical section. |
| 710 | */ |
| 711 | lsu::registry_enum *lsu::registry_session::_lookup_enum( |
| 712 | const lsu::registry_enum *reg_enum_lookup) const |
| 713 | { |
| 714 | lsu::registry_enum *reg_enum = NULL; |
| 715 | struct lttng_ht_node_str *node; |
| 716 | struct lttng_ht_iter iter; |
| 717 | |
| 718 | ASSERT_RCU_READ_LOCKED(); |
| 719 | |
| 720 | cds_lfht_lookup(_enums->ht, ht_hash_enum((void *) reg_enum_lookup, lttng_ht_seed), |
| 721 | ht_match_enum, reg_enum_lookup, &iter.iter); |
| 722 | node = lttng_ht_iter_get_node_str(&iter); |
| 723 | if (!node) { |
| 724 | goto end; |
| 725 | } |
| 726 | |
| 727 | DIAGNOSTIC_PUSH |
| 728 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 729 | reg_enum = lttng::utils::container_of(node, &lsu::registry_enum::node); |
| 730 | DIAGNOSTIC_POP |
| 731 | |
| 732 | end: |
| 733 | return reg_enum; |
| 734 | } |
| 735 | |
| 736 | /* |
| 737 | * Create a lsu::registry_enum from the given parameters and add it to the |
| 738 | * registry hash table, or find it if already there. |
| 739 | * |
| 740 | * Should be called with session registry mutex held. |
| 741 | * |
| 742 | * We receive ownership of entries. |
| 743 | */ |
| 744 | void lsu::registry_session::create_or_find_enum( |
| 745 | int session_objd, const char *enum_name, |
| 746 | struct lttng_ust_ctl_enum_entry *raw_entries, size_t nr_entries, |
| 747 | uint64_t *enum_id) |
| 748 | { |
| 749 | struct cds_lfht_node *nodep; |
| 750 | lsu::registry_enum *reg_enum = NULL, *old_reg_enum; |
| 751 | lttng::urcu::read_lock_guard read_lock_guard; |
| 752 | auto entries = lttng::make_unique_wrapper<lttng_ust_ctl_enum_entry, lttng::free>(raw_entries); |
| 753 | |
| 754 | LTTNG_ASSERT(enum_name); |
| 755 | |
| 756 | /* |
| 757 | * This should not happen but since it comes from the UST tracer, an |
| 758 | * external party, don't assert and simply validate values. |
| 759 | */ |
| 760 | if (session_objd < 0) { |
| 761 | LTTNG_THROW_INVALID_ARGUMENT_ERROR(fmt::format( |
| 762 | "Invalid parameters used to create or look-up enumeration from registry session: session_objd = {}", |
| 763 | session_objd)); |
| 764 | } |
| 765 | if (nr_entries == 0) { |
| 766 | LTTNG_THROW_INVALID_ARGUMENT_ERROR(fmt::format( |
| 767 | "Invalid parameters used to create or look-up enumeration from registry session: nr_entries = {}", |
| 768 | nr_entries)); |
| 769 | } |
| 770 | if (lttng_strnlen(enum_name, LTTNG_UST_ABI_SYM_NAME_LEN) == |
| 771 | LTTNG_UST_ABI_SYM_NAME_LEN) { |
| 772 | LTTNG_THROW_INVALID_ARGUMENT_ERROR( |
| 773 | "Invalid parameters used to create or look-up enumeration from registry session: enumeration name is not null terminated"); |
| 774 | } |
| 775 | |
| 776 | if (entries->start.signedness) { |
| 777 | reg_enum = new lsu::registry_signed_enum( |
| 778 | enum_name, entries.get(), nr_entries); |
| 779 | } else { |
| 780 | reg_enum = new lsu::registry_unsigned_enum( |
| 781 | enum_name, entries.get(), nr_entries); |
| 782 | } |
| 783 | |
| 784 | old_reg_enum = _lookup_enum(reg_enum); |
| 785 | if (old_reg_enum) { |
| 786 | DBG("enum %s already in sess_objd: %u", enum_name, session_objd); |
| 787 | /* Fall through. Use prior enum. */ |
| 788 | destroy_enum(reg_enum); |
| 789 | reg_enum = old_reg_enum; |
| 790 | } else { |
| 791 | DBG("UST registry creating enum: %s, sess_objd: %u", |
| 792 | enum_name, session_objd); |
| 793 | if (_next_enum_id == -1ULL) { |
| 794 | destroy_enum(reg_enum); |
| 795 | LTTNG_THROW_ERROR("Failed to allocate unique enumeration ID as it would overflow"); |
| 796 | } |
| 797 | |
| 798 | reg_enum->id = _next_enum_id++; |
| 799 | nodep = cds_lfht_add_unique(_enums->ht, |
| 800 | ht_hash_enum(reg_enum, lttng_ht_seed), |
| 801 | ht_match_enum_id, reg_enum, |
| 802 | ®_enum->node.node); |
| 803 | LTTNG_ASSERT(nodep == ®_enum->node.node); |
| 804 | } |
| 805 | |
| 806 | DBG("UST registry reply with enum %s with id %" PRIu64 " in sess_objd: %u", |
| 807 | enum_name, reg_enum->id, session_objd); |
| 808 | *enum_id = reg_enum->id; |
| 809 | } |