2 * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 * SPDX-License-Identifier: GPL-2.0-only
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 "ust-app.hpp"
15 #include "ust-field-convert.hpp"
16 #include "ust-registry.hpp"
18 #include <common/compat/directory-handle.hpp>
19 #include <common/error.hpp>
20 #include <common/exception.hpp>
21 #include <common/format.hpp>
22 #include <common/hashtable/utils.hpp>
23 #include <common/macros.hpp>
24 #include <common/make-unique.hpp>
25 #include <common/pthread-lock.hpp>
26 #include <common/runas.hpp>
27 #include <common/time.hpp>
28 #include <common/urcu.hpp>
36 namespace ls
= lttng::sessiond
;
37 namespace lst
= lttng::sessiond::trace
;
38 namespace lsu
= lttng::sessiond::ust
;
41 lttng_uuid
generate_uuid_or_throw()
45 if (lttng_uuid_generate(new_uuid
)) {
46 LTTNG_THROW_POSIX("Failed to generate UST uuid", errno
);
52 int get_count_order(unsigned int count
)
56 order
= lttng_fls(count
) - 1;
57 if (count
& (count
- 1)) {
61 LTTNG_ASSERT(order
>= 0);
65 void clear_metadata_file(int fd
)
67 const auto lseek_ret
= lseek(fd
, 0, SEEK_SET
);
69 LTTNG_THROW_POSIX("Failed to seek to the beginning of the metadata file while clearing it", errno
);
72 const auto ret
= ftruncate(fd
, 0);
74 LTTNG_THROW_POSIX("Failed to truncate the metadata file while clearing it", errno
);
79 * Validate that the id has reached the maximum allowed or not.
81 bool is_max_channel_id(uint32_t id
)
83 return id
== UINT32_MAX
;
86 void destroy_channel_rcu(struct rcu_head
*head
)
89 DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
90 lsu::registry_channel
*chan
=
91 lttng::utils::container_of(head
, &lsu::registry_channel::_rcu_head
);
98 * Destroy every element of the registry and free the memory. This does NOT
99 * free the registry pointer since it might not have been allocated before so
100 * it's the caller responsability.
102 * Called from ~registry_session(), must not throw.
104 void destroy_channel(lsu::registry_channel
*chan
, bool notify
) noexcept
106 struct lttng_ht_iter iter
;
107 lttng::sessiond::ust::registry_event
*event
;
108 enum lttng_error_code cmd_ret
;
113 cmd_ret
= notification_thread_command_remove_channel(
114 the_notification_thread_handle
,
115 chan
->_consumer_key
, LTTNG_DOMAIN_UST
);
116 if (cmd_ret
!= LTTNG_OK
) {
117 ERR("Failed to remove channel from notification thread");
122 lttng::urcu::read_lock_guard read_lock_guard
;
124 /* Destroy all event associated with this registry. */
126 DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
127 cds_lfht_for_each_entry(
128 chan
->_events
->ht
, &iter
.iter
, event
, _node
) {
129 /* Delete the node from the ht and free it. */
130 ust_registry_channel_destroy_event(chan
, event
);
135 call_rcu(&chan
->_rcu_head
, destroy_channel_rcu
);
138 void destroy_enum(lsu::registry_enum
*reg_enum
)
147 void destroy_enum_rcu(struct rcu_head
*head
)
150 DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
151 lsu::registry_enum
*reg_enum
=
152 lttng::utils::container_of(head
, &lsu::registry_enum::rcu_head
);
155 destroy_enum(reg_enum
);
159 * Hash table match function for enumerations in the session. Match is
160 * performed on enumeration name, and confirmed by comparing the enum
163 int ht_match_enum(struct cds_lfht_node
*node
, const void *_key
)
165 lsu::registry_enum
*_enum
;
166 const lsu::registry_enum
*key
;
172 DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
173 _enum
= caa_container_of(node
, lsu::registry_enum
,
178 key
= (lsu::registry_enum
*) _key
;
180 return *_enum
== *key
;
184 * Hash table match function for enumerations in the session. Match is
185 * performed by enumeration ID.
187 int ht_match_enum_id(struct cds_lfht_node
*node
, const void *_key
)
189 lsu::registry_enum
*_enum
;
190 const lsu::registry_enum
*key
= (lsu::registry_enum
*) _key
;
196 DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
197 _enum
= caa_container_of(node
, lsu::registry_enum
, node
.node
);
202 if (_enum
->id
!= key
->id
) {
214 * Hash table hash function for enumerations in the session. The
215 * enumeration name is used for hashing.
217 unsigned long ht_hash_enum(void *_key
, unsigned long seed
)
219 lsu::registry_enum
*key
= (lsu::registry_enum
*) _key
;
222 return hash_key_str(key
->name
.c_str(), seed
);
227 void lsu::details::locked_registry_session_release(lsu::registry_session
*session
)
229 pthread_mutex_unlock(&session
->_lock
);
232 lsu::registry_session::registry_session(const struct lst::abi
& in_abi
,
235 const char *root_shm_path
,
236 const char *shm_path
,
239 uint64_t tracing_id
) :
240 lst::trace_class(in_abi
, generate_uuid_or_throw()),
241 _root_shm_path
{root_shm_path
? root_shm_path
: ""},
242 _shm_path
{shm_path
? shm_path
: ""},
243 _metadata_path
{_shm_path
.size() > 0 ?
244 fmt::format("{}/metadata", _shm_path
) : std::string("")},
247 _app_tracer_version
{.major
= major
, .minor
= minor
},
248 _tracing_id
{tracing_id
},
249 _clock
{lttng::make_unique
<lsu::clock_class
>()},
250 _metadata_generating_visitor
{lttng::make_unique
<ls::tsdl::trace_class_visitor
>(abi
,
251 [this](const std::string
& fragment
) {
252 _append_metadata_fragment(fragment
);
255 pthread_mutex_init(&_lock
, NULL
);
256 if (_shm_path
.size() > 0) {
257 if (run_as_mkdir_recursive(_shm_path
.c_str(), S_IRWXU
| S_IRWXG
, euid
, egid
)) {
258 LTTNG_THROW_POSIX("run_as_mkdir_recursive", errno
);
262 if (_metadata_path
.size() > 0) {
263 /* Create metadata file. */
264 const int ret
= run_as_open(_metadata_path
.c_str(), O_WRONLY
| O_CREAT
| O_EXCL
,
265 S_IRUSR
| S_IWUSR
, euid
, egid
);
267 LTTNG_THROW_POSIX(fmt::format("Failed to open metadata file during registry session creation: path = {}",
268 _metadata_path
), errno
);
274 _enums
.reset(lttng_ht_new(0, LTTNG_HT_TYPE_STRING
));
276 LTTNG_THROW_POSIX("Failed to create enums hash table", ENOMEM
);
279 /* hash/match functions are specified at call site. */
280 _enums
->match_fct
= NULL
;
281 _enums
->hash_fct
= NULL
;
283 _channels
.reset(lttng_ht_new(0, LTTNG_HT_TYPE_U64
));
285 LTTNG_THROW_POSIX("Failed to create channels hash table", ENOMEM
);
290 * For a given enumeration in a registry, delete the entry and destroy
293 * Note that this is used by ~registry_session() and must not throw.
295 void lsu::registry_session::_destroy_enum(lsu::registry_enum
*reg_enum
) noexcept
298 lttng::urcu::read_lock_guard read_lock_guard
;
300 LTTNG_ASSERT(reg_enum
);
301 ASSERT_RCU_READ_LOCKED();
303 /* Delete the node first. */
304 struct lttng_ht_iter iter
;
305 iter
.iter
.node
= ®_enum
->node
.node
;
306 ret
= lttng_ht_del(_enums
.get(), &iter
);
308 call_rcu(®_enum
->rcu_head
, destroy_enum_rcu
);
311 lsu::registry_session::~registry_session()
314 struct lttng_ht_iter iter
;
315 lsu::registry_channel
*chan
;
316 lsu::registry_enum
*reg_enum
;
318 /* On error, EBUSY can be returned if lock. Code flow error. */
319 ret
= pthread_mutex_destroy(&_lock
);
323 lttng::urcu::read_lock_guard read_lock_guard
;
325 /* Destroy all event associated with this registry. */
327 DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
328 cds_lfht_for_each_entry(_channels
->ht
, &iter
.iter
, chan
, _node
.node
) {
329 /* Delete the node from the ht and free it. */
330 ret
= lttng_ht_del(_channels
.get(), &iter
);
332 destroy_channel(chan
, true);
338 if (_metadata_fd
>= 0) {
339 ret
= close(_metadata_fd
);
344 ret
= run_as_unlink(_metadata_path
.c_str(), _uid
, _gid
);
350 if (_root_shm_path
[0]) {
351 /* Try to delete the directory hierarchy. */
352 (void) run_as_rmdir_recursive(_root_shm_path
.c_str(), _uid
, _gid
,
353 LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG
);
356 /* Destroy the enum hash table */
358 lttng::urcu::read_lock_guard read_lock_guard
;
360 /* Destroy all enum entries associated with this registry. */
362 DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
363 cds_lfht_for_each_entry (_enums
->ht
, &iter
.iter
, reg_enum
, node
.node
) {
364 _destroy_enum(reg_enum
);
370 lsu::registry_session::locked_ptr
lsu::registry_session::lock() noexcept
372 pthread_mutex_lock(&_lock
);
373 return locked_ptr(this);
377 * Initialize registry with default values.
379 void lsu::registry_session::add_channel(uint64_t key
)
381 lttng::pthread::lock_guard
session_lock_guard(_lock
);
384 * Assign a channel ID right now since the event notification comes
385 * *before* the channel notify so the ID needs to be set at this point so
386 * the metadata can be dumped for that event.
388 if (is_max_channel_id(_used_channel_id
)) {
389 LTTNG_THROW_ERROR(fmt::format("Failed to allocate unique id for channel under session while adding channel"));
392 auto chan
= new lsu::registry_channel(
393 _get_next_channel_id(),
394 /* Registered channel listener. */
395 [this](const lsu::registry_channel
& registered_channel
) {
397 * Channel registration completed, serialize it's layout's
400 registered_channel
.accept(*_metadata_generating_visitor
);
402 /* Added event listener. */
403 [this](const lsu::registry_channel
& channel
,
404 const lsu::registry_event
& added_event
) {
406 * The channel and its event classes will be dumped at once when
407 * it is registered. This check prevents event classes from being
408 * declared before their stream class.
410 if (channel
.is_registered()) {
411 added_event
.accept(*_metadata_generating_visitor
);
415 lttng::urcu::read_lock_guard rcu_read_lock_guard
;
416 lttng_ht_node_init_u64(&chan
->_node
, key
);
417 lttng_ht_add_unique_u64(_channels
.get(), &chan
->_node
);
420 lttng::sessiond::ust::registry_channel
& lsu::registry_session::get_channel(
421 uint64_t channel_key
) const
423 lttng::urcu::read_lock_guard read_lock_guard
;
424 struct lttng_ht_node_u64
*node
;
425 struct lttng_ht_iter iter
;
427 ASSERT_LOCKED(_lock
);
429 lttng_ht_lookup(_channels
.get(), &channel_key
, &iter
);
430 node
= lttng_ht_iter_get_node_u64(&iter
);
432 LTTNG_THROW_INVALID_ARGUMENT_ERROR(fmt::format(
433 "Invalid channel key provided: channel key = {}", channel_key
));
437 DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
438 auto chan
= lttng::utils::container_of(node
, &lsu::registry_channel::_node
);
443 void lsu::registry_session::remove_channel(uint64_t channel_key
, bool notify
)
445 struct lttng_ht_iter iter
;
447 lttng::urcu::read_lock_guard read_lock_guard
;
449 ASSERT_LOCKED(_lock
);
450 auto& channel
= get_channel(channel_key
);
452 iter
.iter
.node
= &channel
._node
.node
;
453 ret
= lttng_ht_del(_channels
.get(), &iter
);
455 destroy_channel(&channel
, notify
);
458 void lsu::registry_session::_visit_environment(
459 lttng::sessiond::trace::trace_class_visitor
& visitor
) const
461 ASSERT_LOCKED(_lock
);
463 visitor
.visit(lst::environment_field
<const char *>("domain", "ust"));
464 visitor
.visit(lst::environment_field
<const char *>("tracer_name", "lttng-ust"));
465 visitor
.visit(lst::environment_field
<int64_t>("tracer_major", _app_tracer_version
.major
));
466 visitor
.visit(lst::environment_field
<int64_t>("tracer_minor", _app_tracer_version
.minor
));
467 visitor
.visit(lst::environment_field
<const char *>("tracer_buffering_scheme",
468 get_buffering_scheme() == LTTNG_BUFFER_PER_PID
? "pid" : "uid"));
469 visitor
.visit(lst::environment_field
<int64_t>("architecture_bit_width", abi
.bits_per_long
));
472 /* The caller already holds the session and session list locks. */
473 ASSERT_SESSION_LIST_LOCKED();
474 const auto session
= lttng::sessiond::find_session_by_id(_tracing_id
);
476 LTTNG_ASSERT(session
);
477 ASSERT_LOCKED(session
->lock
);
479 visitor
.visit(lst::environment_field
<const char *>("trace_name",
480 session
->has_auto_generated_name
? DEFAULT_SESSION_NAME
:
482 visitor
.visit(lst::environment_field
<std::string
>("trace_creation_datetime",
483 lttng::utils::time_to_iso8601_str(session
->creation_time
)));
484 visitor
.visit(lst::environment_field
<const char *>("hostname", session
->hostname
));
488 void lsu::registry_session::_accept_on_clock_classes(lst::trace_class_visitor
& visitor
) const
490 ASSERT_LOCKED(_lock
);
491 _clock
->accept(visitor
);
494 void lsu::registry_session::_accept_on_stream_classes(lst::trace_class_visitor
& visitor
) const
496 ASSERT_LOCKED(_lock
);
498 std::vector
<const lttng::sessiond::ust::registry_channel
*> sorted_stream_classes
;
501 lttng::urcu::read_lock_guard rcu_lock_guard
;
502 const lsu::registry_channel
*channel
;
503 lttng_ht_iter channel_it
;
506 DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
507 cds_lfht_for_each_entry(_channels
->ht
, &channel_it
.iter
, channel
, _node
.node
) {
508 sorted_stream_classes
.emplace_back(channel
);
513 std::sort(sorted_stream_classes
.begin(), sorted_stream_classes
.end(),
514 [](const lttng::sessiond::ust::registry_channel
*a
,
515 const lttng::sessiond::ust::registry_channel
*b
) {
516 return a
->id
< b
->id
;
519 for (const auto stream_class
: sorted_stream_classes
) {
520 stream_class
->accept(visitor
);
525 * Return next available channel id and increment the used counter. The
526 * is_max_channel_id function MUST be called before in order to validate
527 * if the maximum number of IDs have been reached. If not, it is safe to call
530 * Return a unique channel ID. If max is reached, the used_channel_id counter
533 uint32_t lsu::registry_session::_get_next_channel_id()
535 if (is_max_channel_id(_used_channel_id
)) {
536 return _used_channel_id
;
540 return _next_channel_id
++;
543 void lsu::registry_session::_increase_metadata_size(size_t reservation_length
)
545 const auto new_len
= _metadata_len
+ reservation_length
;
546 auto new_alloc_len
= new_len
;
547 const auto old_alloc_len
= _metadata_alloc_len
;
549 /* Rounding the new allocation length to the next power of 2 would overflow. */
550 if (new_alloc_len
> (UINT32_MAX
>> 1)) {
551 LTTNG_THROW_ERROR("Failed to reserve trace metadata storage as the new size would overflow");
554 /* The current allocation length is already the largest we can afford. */
555 if ((old_alloc_len
<< 1) > (UINT32_MAX
>> 1)) {
556 LTTNG_THROW_ERROR("Failed to reserve trace metadata storage as the max size was already reached");
559 if (new_alloc_len
> old_alloc_len
) {
560 new_alloc_len
= std::max
<size_t>(
561 1U << get_count_order(new_alloc_len
), old_alloc_len
<< 1);
563 auto newptr
= (char *) realloc(_metadata
, new_alloc_len
);
565 LTTNG_THROW_POSIX("Failed to allocate trace metadata storage", errno
);
570 /* We zero directly the memory from start of allocation. */
571 memset(&_metadata
[old_alloc_len
], 0, new_alloc_len
- old_alloc_len
);
572 _metadata_alloc_len
= new_alloc_len
;
575 _metadata_len
+= reservation_length
;
578 void lsu::registry_session::_append_metadata_fragment(const std::string
& fragment
)
580 const auto offset
= _metadata_len
;
582 _increase_metadata_size(fragment
.size());
583 memcpy(&_metadata
[offset
], fragment
.c_str(), fragment
.size());
585 if (_metadata_fd
>= 0) {
586 const auto bytes_written
=
587 lttng_write(_metadata_fd
, fragment
.c_str(), fragment
.size());
589 if (bytes_written
!= fragment
.size()) {
590 LTTNG_THROW_POSIX("Failed to write trace metadata fragment to file",
596 void lsu::registry_session::_reset_metadata()
598 _metadata_len_sent
= 0;
599 memset(_metadata
, 0, _metadata_alloc_len
);
602 if (_metadata_fd
> 0) {
603 /* Clear the metadata file's content. */
604 clear_metadata_file(_metadata_fd
);
608 void lsu::registry_session::_generate_metadata()
610 accept(*_metadata_generating_visitor
);
613 void lsu::registry_session::regenerate_metadata()
615 lttng::pthread::lock_guard
registry_lock(_lock
);
617 /* Resample the clock */
618 _clock
= lttng::make_unique
<lsu::clock_class
>();
622 _generate_metadata();
626 * Lookup enumeration by enum ID.
628 * Note that there is no need to lock the registry session as this only
629 * performs an RCU-protected look-up. The function also return an rcu-protected
630 * reference, which ensures that the caller keeps the RCU read lock until it
631 * disposes of the object.
633 lsu::registry_enum::const_rcu_protected_reference
634 lsu::registry_session::get_enumeration(const char *enum_name
, uint64_t enum_id
) const
636 lsu::registry_enum
*reg_enum
= NULL
;
637 struct lttng_ht_node_str
*node
;
638 struct lttng_ht_iter iter
;
639 lttng::urcu::unique_read_lock rcu_lock
;
641 * Hack: only the name is used for hashing; the rest of the attributes
644 lsu::registry_signed_enum
reg_enum_lookup(enum_name
, nullptr, 0);
646 ASSERT_RCU_READ_LOCKED();
648 reg_enum_lookup
.id
= enum_id
;
649 cds_lfht_lookup(_enums
->ht
,
650 ht_hash_enum((void *) ®_enum_lookup
, lttng_ht_seed
),
651 ht_match_enum_id
, ®_enum_lookup
, &iter
.iter
);
652 node
= lttng_ht_iter_get_node_str(&iter
);
654 LTTNG_THROW_PROTOCOL_ERROR(fmt::format(
655 "Unknown enumeration referenced by application event field: enum name = `{}`, enum id = {}",
656 enum_name
, enum_id
));
660 DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
661 reg_enum
= lttng::utils::container_of(node
, &lsu::registry_enum::node
);
664 return lsu::registry_enum::const_rcu_protected_reference
{*reg_enum
, std::move(rcu_lock
)};
668 * Lookup enumeration by name and comparing enumeration entries.
669 * Needs to be called from RCU read-side critical section.
671 lsu::registry_enum
*lsu::registry_session::_lookup_enum(
672 const lsu::registry_enum
*reg_enum_lookup
) const
674 lsu::registry_enum
*reg_enum
= NULL
;
675 struct lttng_ht_node_str
*node
;
676 struct lttng_ht_iter iter
;
678 ASSERT_RCU_READ_LOCKED();
680 cds_lfht_lookup(_enums
->ht
, ht_hash_enum((void *) reg_enum_lookup
, lttng_ht_seed
),
681 ht_match_enum
, reg_enum_lookup
, &iter
.iter
);
682 node
= lttng_ht_iter_get_node_str(&iter
);
688 DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
689 reg_enum
= lttng::utils::container_of(node
, &lsu::registry_enum::node
);
697 * Create a lsu::registry_enum from the given parameters and add it to the
698 * registry hash table, or find it if already there.
700 * Should be called with session registry mutex held.
702 * We receive ownership of entries.
704 void lsu::registry_session::create_or_find_enum(
705 int session_objd
, const char *enum_name
,
706 struct lttng_ust_ctl_enum_entry
*raw_entries
, size_t nr_entries
,
709 struct cds_lfht_node
*nodep
;
710 lsu::registry_enum
*reg_enum
= NULL
, *old_reg_enum
;
711 lttng::urcu::read_lock_guard read_lock_guard
;
712 auto entries
= lttng::make_unique_wrapper
<lttng_ust_ctl_enum_entry
, lttng::free
>(raw_entries
);
714 LTTNG_ASSERT(enum_name
);
717 * This should not happen but since it comes from the UST tracer, an
718 * external party, don't assert and simply validate values.
720 if (session_objd
< 0) {
721 LTTNG_THROW_INVALID_ARGUMENT_ERROR(fmt::format(
722 "Invalid parameters used to create or look-up enumeration from registry session: session_objd = {}",
725 if (nr_entries
== 0) {
726 LTTNG_THROW_INVALID_ARGUMENT_ERROR(fmt::format(
727 "Invalid parameters used to create or look-up enumeration from registry session: nr_entries = {}",
730 if (lttng_strnlen(enum_name
, LTTNG_UST_ABI_SYM_NAME_LEN
) ==
731 LTTNG_UST_ABI_SYM_NAME_LEN
) {
732 LTTNG_THROW_INVALID_ARGUMENT_ERROR(
733 "Invalid parameters used to create or look-up enumeration from registry session: enumeration name is not null terminated");
736 if (entries
->start
.signedness
) {
737 reg_enum
= new lsu::registry_signed_enum(
738 enum_name
, entries
.get(), nr_entries
);
740 reg_enum
= new lsu::registry_unsigned_enum(
741 enum_name
, entries
.get(), nr_entries
);
744 old_reg_enum
= _lookup_enum(reg_enum
);
746 DBG("enum %s already in sess_objd: %u", enum_name
, session_objd
);
747 /* Fall through. Use prior enum. */
748 destroy_enum(reg_enum
);
749 reg_enum
= old_reg_enum
;
751 DBG("UST registry creating enum: %s, sess_objd: %u",
752 enum_name
, session_objd
);
753 if (_next_enum_id
== -1ULL) {
754 destroy_enum(reg_enum
);
755 LTTNG_THROW_ERROR("Failed to allocate unique enumeration ID as it would overflow");
758 reg_enum
->id
= _next_enum_id
++;
759 nodep
= cds_lfht_add_unique(_enums
->ht
,
760 ht_hash_enum(reg_enum
, lttng_ht_seed
),
761 ht_match_enum_id
, reg_enum
,
762 ®_enum
->node
.node
);
763 LTTNG_ASSERT(nodep
== ®_enum
->node
.node
);
766 DBG("UST registry reply with enum %s with id %" PRIu64
" in sess_objd: %u",
767 enum_name
, reg_enum
->id
, session_objd
);
768 *enum_id
= reg_enum
->id
;