X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-registry-session.cpp;h=255a5ec8176ce96dc17c4e6e5a446549735aea8d;hb=97f630d42cd12a475293af66e75a71ab7b490633;hp=bb678fe4da4c75763759c9b2e6e1fc5aeb213b54;hpb=b0f2e8db59fcadc8f4b06a94175792be3c431004;p=lttng-tools.git diff --git a/src/bin/lttng-sessiond/ust-registry-session.cpp b/src/bin/lttng-sessiond/ust-registry-session.cpp index bb678fe4d..255a5ec81 100644 --- a/src/bin/lttng-sessiond/ust-registry-session.cpp +++ b/src/bin/lttng-sessiond/ust-registry-session.cpp @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -131,6 +132,94 @@ void destroy_channel(lsu::registry_channel *chan, bool notify) call_rcu(&chan->_rcu_head, destroy_channel_rcu); } + +void destroy_enum(lsu::registry_enum *reg_enum) +{ + if (!reg_enum) { + return; + } + + delete reg_enum; +} + +void destroy_enum_rcu(struct rcu_head *head) +{ + DIAGNOSTIC_PUSH + DIAGNOSTIC_IGNORE_INVALID_OFFSETOF + lsu::registry_enum *reg_enum = + caa_container_of(head, lsu::registry_enum, rcu_head); + DIAGNOSTIC_POP + + destroy_enum(reg_enum); +} + +/* + * Hash table match function for enumerations in the session. Match is + * performed on enumeration name, and confirmed by comparing the enum + * entries. + */ +int ht_match_enum(struct cds_lfht_node *node, const void *_key) +{ + lsu::registry_enum *_enum; + const lsu::registry_enum *key; + + LTTNG_ASSERT(node); + LTTNG_ASSERT(_key); + + DIAGNOSTIC_PUSH + DIAGNOSTIC_IGNORE_INVALID_OFFSETOF + _enum = caa_container_of(node, lsu::registry_enum, + node.node); + DIAGNOSTIC_POP + + LTTNG_ASSERT(_enum); + key = (lsu::registry_enum *) _key; + + return *_enum == *key; +} + +/* + * Hash table match function for enumerations in the session. Match is + * performed by enumeration ID. + */ +int ht_match_enum_id(struct cds_lfht_node *node, const void *_key) +{ + lsu::registry_enum *_enum; + const lsu::registry_enum *key = (lsu::registry_enum *) _key; + + LTTNG_ASSERT(node); + LTTNG_ASSERT(_key); + + DIAGNOSTIC_PUSH + DIAGNOSTIC_IGNORE_INVALID_OFFSETOF + _enum = caa_container_of(node, lsu::registry_enum, node.node); + DIAGNOSTIC_POP + + LTTNG_ASSERT(_enum); + + if (_enum->id != key->id) { + goto no_match; + } + + /* Match. */ + return 1; + +no_match: + return 0; +} + +/* + * Hash table hash function for enumerations in the session. The + * enumeration name is used for hashing. + */ +unsigned long ht_hash_enum(void *_key, unsigned long seed) +{ + lsu::registry_enum *key = (lsu::registry_enum *) _key; + + LTTNG_ASSERT(key); + return hash_key_str(key->name.c_str(), seed); +} + } /* namespace */ void lsu::details::locked_registry_session_release(lsu::registry_session *session) @@ -147,44 +236,33 @@ lsu::registry_session::registry_session(const struct lst::abi& in_abi, gid_t egid, uint64_t tracing_id) : lst::trace_class(in_abi, generate_uuid_or_throw()), + _root_shm_path{root_shm_path ? root_shm_path : ""}, + _shm_path{shm_path ? shm_path : ""}, + _metadata_path{_shm_path.size() > 0 ? + fmt::format("{}/metadata", _shm_path) : std::string("")}, _uid{euid}, _gid{egid}, - _app_tracer_version_major{major}, - _app_tracer_version_minor{minor}, + _app_tracer_version{.major = major, .minor = minor}, _tracing_id{tracing_id}, - _metadata_generating_visitor{lttng::make_unique( - abi, [this](const std::string& fragment) { + _metadata_generating_visitor{lttng::make_unique(abi, + [this](const std::string& fragment) { _append_metadata_fragment(fragment); })} { pthread_mutex_init(&_lock, NULL); - strncpy(_root_shm_path, root_shm_path, sizeof(_root_shm_path)); - _root_shm_path[sizeof(_root_shm_path) - 1] = '\0'; - if (shm_path[0]) { - strncpy(_shm_path, shm_path, sizeof(_shm_path)); - _shm_path[sizeof(_shm_path) - 1] = '\0'; - strncpy(_metadata_path, shm_path, sizeof(_metadata_path)); - _metadata_path[sizeof(_metadata_path) - 1] = '\0'; - strncat(_metadata_path, "/metadata", - sizeof(_metadata_path) - strlen(_metadata_path) - 1); - } - - if (_shm_path[0]) { - if (run_as_mkdir_recursive(_shm_path, S_IRWXU | S_IRWXG, euid, egid)) { + if (_shm_path.size() > 0) { + if (run_as_mkdir_recursive(_shm_path.c_str(), S_IRWXU | S_IRWXG, euid, egid)) { LTTNG_THROW_POSIX("run_as_mkdir_recursive", errno); } } - if (_metadata_path[0]) { + if (_metadata_path.size() > 0) { /* Create metadata file. */ - const int ret = run_as_open(_metadata_path, O_WRONLY | O_CREAT | O_EXCL, + const int ret = run_as_open(_metadata_path.c_str(), O_WRONLY | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR, euid, egid); - if (ret < 0) { - std::stringstream ss; - - ss << "Opening metadata file '" << _metadata_path << "'"; - LTTNG_THROW_POSIX(ss.str(), errno); + LTTNG_THROW_POSIX(fmt::format("Failed to open metadata file during registry session creation: path = {}", + _metadata_path), errno); } _metadata_fd = ret; @@ -205,6 +283,26 @@ lsu::registry_session::registry_session(const struct lst::abi& in_abi, } } +/* + * For a given enumeration in a registry, delete the entry and destroy + * the enumeration. + */ +void lsu::registry_session::_destroy_enum(lsu::registry_enum *reg_enum) +{ + int ret; + lttng::urcu::read_lock_guard read_lock_guard; + + LTTNG_ASSERT(reg_enum); + ASSERT_RCU_READ_LOCKED(); + + /* Delete the node first. */ + struct lttng_ht_iter iter; + iter.iter.node = ®_enum->node.node; + ret = lttng_ht_del(_enums.get(), &iter); + LTTNG_ASSERT(!ret); + call_rcu(®_enum->rcu_head, destroy_enum_rcu); +} + lsu::registry_session::~registry_session() { int ret; @@ -238,7 +336,7 @@ lsu::registry_session::~registry_session() PERROR("close"); } - ret = run_as_unlink(_metadata_path, _uid, _gid); + ret = run_as_unlink(_metadata_path.c_str(), _uid, _gid); if (ret) { PERROR("unlink"); } @@ -246,26 +344,25 @@ lsu::registry_session::~registry_session() if (_root_shm_path[0]) { /* Try to delete the directory hierarchy. */ - (void) run_as_rmdir_recursive(_root_shm_path, _uid, _gid, + (void) run_as_rmdir_recursive(_root_shm_path.c_str(), _uid, _gid, LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG); } /* Destroy the enum hash table */ if (_enums) { - rcu_read_lock(); + lttng::urcu::read_lock_guard read_lock_guard; + /* Destroy all enum entries associated with this registry. */ DIAGNOSTIC_PUSH DIAGNOSTIC_IGNORE_INVALID_OFFSETOF cds_lfht_for_each_entry (_enums->ht, &iter.iter, reg_enum, node.node) { - ust_registry_destroy_enum(this, reg_enum); + _destroy_enum(reg_enum); } DIAGNOSTIC_POP - - rcu_read_unlock(); } } -lsu::registry_session::locked_ptr lsu::registry_session::lock() +lsu::registry_session::locked_ptr lsu::registry_session::lock() noexcept { pthread_mutex_lock(&_lock); return locked_ptr(this); @@ -360,8 +457,8 @@ void lsu::registry_session::_visit_environment( visitor.visit(lst::environment_field("domain", "ust")); visitor.visit(lst::environment_field("tracer_name", "lttng-ust")); - visitor.visit(lst::environment_field("tracer_major", _app_tracer_version_major)); - visitor.visit(lst::environment_field("tracer_minor", _app_tracer_version_minor)); + visitor.visit(lst::environment_field("tracer_major", _app_tracer_version.major)); + visitor.visit(lst::environment_field("tracer_minor", _app_tracer_version.minor)); visitor.visit(lst::environment_field("tracer_buffering_scheme", get_buffering_scheme() == LTTNG_BUFFER_PER_PID ? "pid" : "uid")); visitor.visit(lst::environment_field("architecture_bit_width", abi.bits_per_long)); @@ -516,3 +613,149 @@ void lsu::registry_session::regenerate_metadata() _reset_metadata(); _generate_metadata(); } + +/* + * Lookup enumeration by enum ID. + * + * Note that there is no need to lock the registry session as this only + * performs an RCU-protected look-up. The function also return an rcu-protected + * reference, which ensures that the caller keeps the RCU read lock until it + * disposes of the object. + */ +lsu::registry_enum::const_rcu_protected_reference +lsu::registry_session::get_enumeration(const char *enum_name, uint64_t enum_id) const +{ + lsu::registry_enum *reg_enum = NULL; + struct lttng_ht_node_str *node; + struct lttng_ht_iter iter; + lttng::urcu::unique_read_lock rcu_lock; + /* + * Hack: only the name is used for hashing; the rest of the attributes + * can be fudged. + */ + lsu::registry_signed_enum reg_enum_lookup(enum_name, nullptr, 0); + + ASSERT_RCU_READ_LOCKED(); + + reg_enum_lookup.id = enum_id; + cds_lfht_lookup(_enums->ht, + ht_hash_enum((void *) ®_enum_lookup, lttng_ht_seed), + ht_match_enum_id, ®_enum_lookup, &iter.iter); + node = lttng_ht_iter_get_node_str(&iter); + if (!node) { + LTTNG_THROW_PROTOCOL_ERROR(fmt::format( + "Unknown enumeration referenced by application event field: enum name = `{}`, enum id = {}", + enum_name, enum_id)); + } + + DIAGNOSTIC_PUSH + DIAGNOSTIC_IGNORE_INVALID_OFFSETOF + reg_enum = caa_container_of(node, lsu::registry_enum, node); + DIAGNOSTIC_POP + + return lsu::registry_enum::const_rcu_protected_reference{*reg_enum, std::move(rcu_lock)}; +} + +/* + * Lookup enumeration by name and comparing enumeration entries. + * Needs to be called from RCU read-side critical section. + */ +lsu::registry_enum *lsu::registry_session::_lookup_enum( + const lsu::registry_enum *reg_enum_lookup) const +{ + lsu::registry_enum *reg_enum = NULL; + struct lttng_ht_node_str *node; + struct lttng_ht_iter iter; + + ASSERT_RCU_READ_LOCKED(); + + cds_lfht_lookup(_enums->ht, ht_hash_enum((void *) reg_enum_lookup, lttng_ht_seed), + ht_match_enum, reg_enum_lookup, &iter.iter); + node = lttng_ht_iter_get_node_str(&iter); + if (!node) { + goto end; + } + + DIAGNOSTIC_PUSH + DIAGNOSTIC_IGNORE_INVALID_OFFSETOF + reg_enum = caa_container_of(node, lsu::registry_enum, node); + DIAGNOSTIC_POP + +end: + return reg_enum; +} + +/* + * Create a lsu::registry_enum from the given parameters and add it to the + * registry hash table, or find it if already there. + * + * Should be called with session registry mutex held. + * + * We receive ownership of entries. + */ +void lsu::registry_session::create_or_find_enum( + int session_objd, const char *enum_name, + struct lttng_ust_ctl_enum_entry *raw_entries, size_t nr_entries, + uint64_t *enum_id) +{ + struct cds_lfht_node *nodep; + lsu::registry_enum *reg_enum = NULL, *old_reg_enum; + lttng::urcu::read_lock_guard read_lock_guard; + auto entries = lttng::make_unique_wrapper(raw_entries); + + LTTNG_ASSERT(enum_name); + + /* + * This should not happen but since it comes from the UST tracer, an + * external party, don't assert and simply validate values. + */ + if (session_objd < 0) { + LTTNG_THROW_INVALID_ARGUMENT_ERROR(fmt::format( + "Invalid parameters used to create or look-up enumeration from registry session: session_objd = {}", + session_objd)); + } + if (nr_entries == 0) { + LTTNG_THROW_INVALID_ARGUMENT_ERROR(fmt::format( + "Invalid parameters used to create or look-up enumeration from registry session: nr_entries = {}", + nr_entries)); + } + if (lttng_strnlen(enum_name, LTTNG_UST_ABI_SYM_NAME_LEN) == + LTTNG_UST_ABI_SYM_NAME_LEN) { + LTTNG_THROW_INVALID_ARGUMENT_ERROR( + "Invalid parameters used to create or look-up enumeration from registry session: enumeration name is not null terminated"); + } + + if (entries->start.signedness) { + reg_enum = new lsu::registry_signed_enum( + enum_name, entries.get(), nr_entries); + } else { + reg_enum = new lsu::registry_unsigned_enum( + enum_name, entries.get(), nr_entries); + } + + old_reg_enum = _lookup_enum(reg_enum); + if (old_reg_enum) { + DBG("enum %s already in sess_objd: %u", enum_name, session_objd); + /* Fall through. Use prior enum. */ + destroy_enum(reg_enum); + reg_enum = old_reg_enum; + } else { + DBG("UST registry creating enum: %s, sess_objd: %u", + enum_name, session_objd); + if (_next_enum_id == -1ULL) { + destroy_enum(reg_enum); + LTTNG_THROW_ERROR("Failed to allocate unique enumeration ID as it would overflow"); + } + + reg_enum->id = _next_enum_id++; + nodep = cds_lfht_add_unique(_enums->ht, + ht_hash_enum(reg_enum, lttng_ht_seed), + ht_match_enum_id, reg_enum, + ®_enum->node.node); + LTTNG_ASSERT(nodep == ®_enum->node.node); + } + + DBG("UST registry reply with enum %s with id %" PRIu64 " in sess_objd: %u", + enum_name, reg_enum->id, session_objd); + *enum_id = reg_enum->id; +} \ No newline at end of file