| 1 | /* |
| 2 | * Copyright (C) 2013 David Goulet <dgoulet@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #define _LGPL_SOURCE |
| 9 | |
| 10 | #include "ust-registry.hpp" |
| 11 | #include "lttng-sessiond.hpp" |
| 12 | #include "notification-thread-commands.hpp" |
| 13 | #include "ust-app.hpp" |
| 14 | #include "ust-registry-session-pid.hpp" |
| 15 | #include "ust-registry-session-uid.hpp" |
| 16 | #include "utils.hpp" |
| 17 | |
| 18 | #include <common/common.hpp> |
| 19 | #include <common/exception.hpp> |
| 20 | #include <common/format.hpp> |
| 21 | #include <common/hashtable/utils.hpp> |
| 22 | #include <common/make-unique-wrapper.hpp> |
| 23 | #include <lttng/lttng.h> |
| 24 | |
| 25 | #include <inttypes.h> |
| 26 | |
| 27 | namespace ls = lttng::sessiond; |
| 28 | namespace lst = lttng::sessiond::trace; |
| 29 | namespace lsu = lttng::sessiond::ust; |
| 30 | |
| 31 | /* |
| 32 | * Hash table match function for enumerations in the session. Match is |
| 33 | * performed on enumeration name, and confirmed by comparing the enum |
| 34 | * entries. |
| 35 | */ |
| 36 | static int ht_match_enum(struct cds_lfht_node *node, const void *_key) |
| 37 | { |
| 38 | lsu::registry_enum *_enum; |
| 39 | const lsu::registry_enum *key; |
| 40 | |
| 41 | LTTNG_ASSERT(node); |
| 42 | LTTNG_ASSERT(_key); |
| 43 | |
| 44 | DIAGNOSTIC_PUSH |
| 45 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 46 | _enum = caa_container_of(node, lsu::registry_enum, |
| 47 | node.node); |
| 48 | DIAGNOSTIC_POP |
| 49 | |
| 50 | LTTNG_ASSERT(_enum); |
| 51 | key = (lsu::registry_enum *) _key; |
| 52 | |
| 53 | return *_enum == *key; |
| 54 | } |
| 55 | |
| 56 | /* |
| 57 | * Hash table match function for enumerations in the session. Match is |
| 58 | * performed by enumeration ID. |
| 59 | */ |
| 60 | static int ht_match_enum_id(struct cds_lfht_node *node, const void *_key) |
| 61 | { |
| 62 | lsu::registry_enum *_enum; |
| 63 | const lsu::registry_enum *key = (lsu::registry_enum *) _key; |
| 64 | |
| 65 | LTTNG_ASSERT(node); |
| 66 | LTTNG_ASSERT(_key); |
| 67 | |
| 68 | DIAGNOSTIC_PUSH |
| 69 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 70 | _enum = caa_container_of(node, lsu::registry_enum, node.node); |
| 71 | DIAGNOSTIC_POP |
| 72 | |
| 73 | LTTNG_ASSERT(_enum); |
| 74 | |
| 75 | if (_enum->id != key->id) { |
| 76 | goto no_match; |
| 77 | } |
| 78 | |
| 79 | /* Match. */ |
| 80 | return 1; |
| 81 | |
| 82 | no_match: |
| 83 | return 0; |
| 84 | } |
| 85 | |
| 86 | /* |
| 87 | * Hash table hash function for enumerations in the session. The |
| 88 | * enumeration name is used for hashing. |
| 89 | */ |
| 90 | static unsigned long ht_hash_enum(void *_key, unsigned long seed) |
| 91 | { |
| 92 | lsu::registry_enum *key = (lsu::registry_enum *) _key; |
| 93 | |
| 94 | LTTNG_ASSERT(key); |
| 95 | return hash_key_str(key->name.c_str(), seed); |
| 96 | } |
| 97 | |
| 98 | /* |
| 99 | * Destroy event function call of the call RCU. |
| 100 | */ |
| 101 | static void ust_registry_event_destroy_rcu(struct rcu_head *head) |
| 102 | { |
| 103 | struct lttng_ht_node_u64 *node = caa_container_of(head, struct lttng_ht_node_u64, head); |
| 104 | DIAGNOSTIC_PUSH |
| 105 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 106 | lttng::sessiond::ust::registry_event *event = |
| 107 | caa_container_of(node, lttng::sessiond::ust::registry_event, _node); |
| 108 | DIAGNOSTIC_POP |
| 109 | |
| 110 | lttng::sessiond::ust::registry_event_destroy(event); |
| 111 | } |
| 112 | |
| 113 | /* |
| 114 | * For a given event in a registry, delete the entry and destroy the event. |
| 115 | * This MUST be called within a RCU read side lock section. |
| 116 | */ |
| 117 | void ust_registry_channel_destroy_event(lsu::registry_channel *chan, |
| 118 | lttng::sessiond::ust::registry_event *event) |
| 119 | { |
| 120 | int ret; |
| 121 | struct lttng_ht_iter iter; |
| 122 | |
| 123 | LTTNG_ASSERT(chan); |
| 124 | LTTNG_ASSERT(event); |
| 125 | ASSERT_RCU_READ_LOCKED(); |
| 126 | |
| 127 | /* Delete the node first. */ |
| 128 | iter.iter.node = &event->_node.node; |
| 129 | ret = lttng_ht_del(chan->_events, &iter); |
| 130 | LTTNG_ASSERT(!ret); |
| 131 | |
| 132 | call_rcu(&event->_node.head, ust_registry_event_destroy_rcu); |
| 133 | |
| 134 | return; |
| 135 | } |
| 136 | |
| 137 | static void destroy_enum(lsu::registry_enum *reg_enum) |
| 138 | { |
| 139 | if (!reg_enum) { |
| 140 | return; |
| 141 | } |
| 142 | |
| 143 | delete reg_enum; |
| 144 | } |
| 145 | |
| 146 | static void destroy_enum_rcu(struct rcu_head *head) |
| 147 | { |
| 148 | DIAGNOSTIC_PUSH |
| 149 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 150 | lsu::registry_enum *reg_enum = |
| 151 | caa_container_of(head, lsu::registry_enum, rcu_head); |
| 152 | DIAGNOSTIC_POP |
| 153 | |
| 154 | destroy_enum(reg_enum); |
| 155 | } |
| 156 | |
| 157 | /* |
| 158 | * Lookup enumeration by name and comparing enumeration entries. |
| 159 | * Needs to be called from RCU read-side critical section. |
| 160 | */ |
| 161 | static lsu::registry_enum *ust_registry_lookup_enum( |
| 162 | lsu::registry_session *session, |
| 163 | const lsu::registry_enum *reg_enum_lookup) |
| 164 | { |
| 165 | lsu::registry_enum *reg_enum = NULL; |
| 166 | struct lttng_ht_node_str *node; |
| 167 | struct lttng_ht_iter iter; |
| 168 | |
| 169 | ASSERT_RCU_READ_LOCKED(); |
| 170 | |
| 171 | cds_lfht_lookup(session->_enums->ht, |
| 172 | ht_hash_enum((void *) reg_enum_lookup, lttng_ht_seed), |
| 173 | ht_match_enum, reg_enum_lookup, &iter.iter); |
| 174 | node = lttng_ht_iter_get_node_str(&iter); |
| 175 | if (!node) { |
| 176 | goto end; |
| 177 | } |
| 178 | |
| 179 | DIAGNOSTIC_PUSH |
| 180 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 181 | reg_enum = caa_container_of(node, lsu::registry_enum, node); |
| 182 | DIAGNOSTIC_POP |
| 183 | |
| 184 | end: |
| 185 | return reg_enum; |
| 186 | } |
| 187 | |
| 188 | /* |
| 189 | * Lookup enumeration by enum ID. |
| 190 | */ |
| 191 | lsu::registry_enum::const_rcu_protected_reference |
| 192 | ust_registry_lookup_enum_by_id(const lsu::registry_session *session, |
| 193 | const char *enum_name, uint64_t enum_id) |
| 194 | { |
| 195 | lsu::registry_enum *reg_enum = NULL; |
| 196 | struct lttng_ht_node_str *node; |
| 197 | struct lttng_ht_iter iter; |
| 198 | lttng::urcu::unique_read_lock rcu_lock; |
| 199 | /* |
| 200 | * Hack: only the name is used for hashing; the rest of the attributes |
| 201 | * can be fudged. |
| 202 | */ |
| 203 | lsu::registry_signed_enum reg_enum_lookup(enum_name, nullptr, 0); |
| 204 | |
| 205 | ASSERT_RCU_READ_LOCKED(); |
| 206 | |
| 207 | reg_enum_lookup.id = enum_id; |
| 208 | cds_lfht_lookup(session->_enums->ht, |
| 209 | ht_hash_enum((void *) ®_enum_lookup, lttng_ht_seed), |
| 210 | ht_match_enum_id, ®_enum_lookup, &iter.iter); |
| 211 | node = lttng_ht_iter_get_node_str(&iter); |
| 212 | if (!node) { |
| 213 | LTTNG_THROW_PROTOCOL_ERROR(fmt::format( |
| 214 | "Unknown enumeration referenced by application event field: enum name = `{}`, enum id = {}", |
| 215 | enum_name, enum_id)); |
| 216 | } |
| 217 | |
| 218 | DIAGNOSTIC_PUSH |
| 219 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 220 | reg_enum = caa_container_of(node, lsu::registry_enum, node); |
| 221 | DIAGNOSTIC_POP |
| 222 | |
| 223 | return lsu::registry_enum::const_rcu_protected_reference{*reg_enum, std::move(rcu_lock)}; |
| 224 | } |
| 225 | |
| 226 | /* |
| 227 | * Create a lsu::registry_enum from the given parameters and add it to the |
| 228 | * registry hash table, or find it if already there. |
| 229 | * |
| 230 | * On success, return 0 else a negative value. |
| 231 | * |
| 232 | * Should be called with session registry mutex held. |
| 233 | * |
| 234 | * We receive ownership of entries. |
| 235 | */ |
| 236 | int ust_registry_create_or_find_enum(lsu::registry_session *session, |
| 237 | int session_objd, char *enum_name, |
| 238 | struct lttng_ust_ctl_enum_entry *raw_entries, size_t nr_entries, |
| 239 | uint64_t *enum_id) |
| 240 | { |
| 241 | int ret = 0; |
| 242 | struct cds_lfht_node *nodep; |
| 243 | lsu::registry_enum *reg_enum = NULL, *old_reg_enum; |
| 244 | auto entries = lttng::make_unique_wrapper<lttng_ust_ctl_enum_entry, lttng::free>(raw_entries); |
| 245 | |
| 246 | LTTNG_ASSERT(session); |
| 247 | LTTNG_ASSERT(enum_name); |
| 248 | |
| 249 | rcu_read_lock(); |
| 250 | |
| 251 | /* |
| 252 | * This should not happen but since it comes from the UST tracer, an |
| 253 | * external party, don't assert and simply validate values. |
| 254 | */ |
| 255 | if (session_objd < 0 || nr_entries == 0 || |
| 256 | lttng_strnlen(enum_name, LTTNG_UST_ABI_SYM_NAME_LEN) == |
| 257 | LTTNG_UST_ABI_SYM_NAME_LEN) { |
| 258 | ret = -EINVAL; |
| 259 | goto end; |
| 260 | } |
| 261 | |
| 262 | try { |
| 263 | if (entries->start.signedness) { |
| 264 | reg_enum = new lsu::registry_signed_enum( |
| 265 | enum_name, entries.get(), nr_entries); |
| 266 | } else { |
| 267 | reg_enum = new lsu::registry_unsigned_enum( |
| 268 | enum_name, entries.get(), nr_entries); |
| 269 | } |
| 270 | } catch (const std::exception& ex) { |
| 271 | ERR("Failed to create ust registry enumeration: %s", ex.what()); |
| 272 | ret = -ENOMEM; |
| 273 | goto end; |
| 274 | } |
| 275 | |
| 276 | old_reg_enum = ust_registry_lookup_enum(session, reg_enum); |
| 277 | if (old_reg_enum) { |
| 278 | DBG("enum %s already in sess_objd: %u", enum_name, session_objd); |
| 279 | /* Fall through. Use prior enum. */ |
| 280 | destroy_enum(reg_enum); |
| 281 | reg_enum = old_reg_enum; |
| 282 | } else { |
| 283 | DBG("UST registry creating enum: %s, sess_objd: %u", |
| 284 | enum_name, session_objd); |
| 285 | if (session->_next_enum_id == -1ULL) { |
| 286 | ret = -EOVERFLOW; |
| 287 | destroy_enum(reg_enum); |
| 288 | goto end; |
| 289 | } |
| 290 | reg_enum->id = session->_next_enum_id++; |
| 291 | nodep = cds_lfht_add_unique(session->_enums->ht, |
| 292 | ht_hash_enum(reg_enum, lttng_ht_seed), |
| 293 | ht_match_enum_id, reg_enum, |
| 294 | ®_enum->node.node); |
| 295 | LTTNG_ASSERT(nodep == ®_enum->node.node); |
| 296 | } |
| 297 | DBG("UST registry reply with enum %s with id %" PRIu64 " in sess_objd: %u", |
| 298 | enum_name, reg_enum->id, session_objd); |
| 299 | *enum_id = reg_enum->id; |
| 300 | end: |
| 301 | rcu_read_unlock(); |
| 302 | return ret; |
| 303 | } |
| 304 | |
| 305 | /* |
| 306 | * For a given enumeration in a registry, delete the entry and destroy |
| 307 | * the enumeration. |
| 308 | * This MUST be called within a RCU read side lock section. |
| 309 | */ |
| 310 | void ust_registry_destroy_enum(lsu::registry_session *reg_session, |
| 311 | lsu::registry_enum *reg_enum) |
| 312 | { |
| 313 | int ret; |
| 314 | struct lttng_ht_iter iter; |
| 315 | |
| 316 | LTTNG_ASSERT(reg_session); |
| 317 | LTTNG_ASSERT(reg_enum); |
| 318 | ASSERT_RCU_READ_LOCKED(); |
| 319 | |
| 320 | /* Delete the node first. */ |
| 321 | iter.iter.node = ®_enum->node.node; |
| 322 | ret = lttng_ht_del(reg_session->_enums.get(), &iter); |
| 323 | LTTNG_ASSERT(!ret); |
| 324 | call_rcu(®_enum->rcu_head, destroy_enum_rcu); |
| 325 | } |
| 326 | |
| 327 | lsu::registry_session *ust_registry_session_per_uid_create(const lttng::sessiond::trace::abi& abi, |
| 328 | uint32_t major, |
| 329 | uint32_t minor, |
| 330 | const char *root_shm_path, |
| 331 | const char *shm_path, |
| 332 | uid_t euid, |
| 333 | gid_t egid, |
| 334 | uint64_t tracing_id, |
| 335 | uid_t tracing_uid) |
| 336 | { |
| 337 | try { |
| 338 | return new lsu::registry_session_per_uid(abi, major, minor, root_shm_path, shm_path, |
| 339 | euid, egid, tracing_id, tracing_uid); |
| 340 | } catch (const std::exception& ex) { |
| 341 | ERR("Failed to create per-uid registry session: %s", ex.what()); |
| 342 | return nullptr; |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | lsu::registry_session *ust_registry_session_per_pid_create(struct ust_app *app, |
| 347 | const lttng::sessiond::trace::abi& abi, |
| 348 | uint32_t major, |
| 349 | uint32_t minor, |
| 350 | const char *root_shm_path, |
| 351 | const char *shm_path, |
| 352 | uid_t euid, |
| 353 | gid_t egid, |
| 354 | uint64_t tracing_id) |
| 355 | { |
| 356 | try { |
| 357 | return new lsu::registry_session_per_pid(*app, abi, major, minor, root_shm_path, |
| 358 | shm_path, euid, egid, tracing_id); |
| 359 | } catch (const std::exception& ex) { |
| 360 | ERR("Failed to create per-pid registry session: %s", ex.what()); |
| 361 | return nullptr; |
| 362 | } |
| 363 | } |
| 364 | |
| 365 | /* |
| 366 | * Destroy session registry. This does NOT free the given pointer since it |
| 367 | * might get passed as a reference. The registry lock should NOT be acquired. |
| 368 | */ |
| 369 | void ust_registry_session_destroy(lsu::registry_session *reg) |
| 370 | { |
| 371 | delete reg; |
| 372 | } |
| 373 | |
| 374 | lsu::registry_enum::registry_enum( |
| 375 | std::string in_name, enum lst::integer_type::signedness in_signedness) : |
| 376 | name{std::move(in_name)}, signedness{in_signedness} |
| 377 | { |
| 378 | cds_lfht_node_init(&this->node.node); |
| 379 | this->rcu_head = {}; |
| 380 | } |
| 381 | |
| 382 | bool lsu::operator==(const lsu::registry_enum& lhs, const lsu::registry_enum& rhs) noexcept |
| 383 | { |
| 384 | if (lhs.signedness != rhs.signedness) { |
| 385 | return false; |
| 386 | } |
| 387 | |
| 388 | return lhs._is_equal(rhs); |
| 389 | } |