Jérémie Galarneau [Wed, 2 Mar 2022 17:37:39 +0000 (12:37 -0500)] 
Fix: relayd: live client fails on clear of multi-domain session
Observed issue
==============
Two test cases of the clear/test_ust test suite occasionally fail in the
integration jobs testing cross-bitness (32/64) LTTng deployments.
Babeltrace fails with the following error when a clear occurs while a
live client consumes a trace:
02-28 16:55:03.262 32362 32362 E PLUGIN/SRC.CTF.LTTNG-LIVE/VIEWER lttng_live_recv@viewer-connection.c:198 [lttng-live] Remote side has closed connection
02-28 16:55:03.262 32362 32362 E PLUGIN/SRC.CTF.LTTNG-LIVE/VIEWER lttng_live_session_get_new_streams@viewer-connection.c:1706 [lttng-live] Error receiving get new streams reply
02-28 16:55:03.262 32362 32362 E PLUGIN/SRC.CTF.LTTNG-LIVE lttng_live_msg_iter_next@lttng-live.c:1665 [lttng-live] Error preparing the next batch of messages: live-iter-status=LTTNG_LIVE_ITERATOR_STATUS_ERROR
02-28 16:55:03.262 32362 32362 W LIB/MSG-ITER bt_message_iterator_next@iterator.c:864 Component input port message iterator's "next" method failed: iter-addr=0x55eab7eb1170, iter-upstream-comp-name="lttng-live", iter-upstream-comp-log-level=WARNING, iter-upstream-comp-class-type=SOURCE, iter-upstream-comp-class-name="lttng-live", iter-upstream-comp-class-partial-descr="Connect to an LTTng relay daemon", iter-upstream-port-type=OUTPUT, iter-upstream-port-name="out", status=ERROR
02-28 16:55:03.262 32362 32362 E PLUGIN/FLT.UTILS.MUXER muxer_upstream_msg_iter_next@muxer.c:454 [muxer] Upstream iterator's next method returned an error: status=ERROR
02-28 16:55:03.262 32362 32362 E PLUGIN/FLT.UTILS.MUXER validate_muxer_upstream_msg_iters@muxer.c:991 [muxer] Cannot validate muxer's upstream message iterator wrapper: muxer-msg-iter-addr=0x55eab7eb1120, muxer-upstream-msg-iter-wrap-addr=0x55eab7eb3a70
02-28 16:55:03.262 32362 32362 E PLUGIN/FLT.UTILS.MUXER muxer_msg_iter_next@muxer.c:1415 [muxer] Cannot get next message: comp-addr=0x55eab7eb0470, muxer-comp-addr=0x55eab7eb0510, muxer-msg-iter-addr=0x55eab7eb1120, msg-iter-addr=0x55eab7eb0fb0, status=ERROR
02-28 16:55:03.262 32362 32362 W LIB/MSG-ITER bt_message_iterator_next@iterator.c:864 Component input port message iterator's "next" method failed: iter-addr=0x55eab7eb0fb0, iter-upstream-comp-name="muxer", iter-upstream-comp-log-level=WARNING, iter-upstream-comp-class-type=FILTER, iter-upstream-comp-class-name="muxer", iter-upstream-comp-class-partial-descr="Sort messages from multiple inpu", iter-upstream-port-type=OUTPUT, iter-upstream-port-name="out", status=ERROR
02-28 16:55:03.262 32362 32362 W LIB/GRAPH consume_graph_sink@graph.c:473 Component's "consume" method failed: status=ERROR, comp-addr=0x55eab7eb0760, comp-name="pretty", comp-log-level=WARNING, comp-class-type=SINK, comp-class-name="pretty", comp-class-partial-descr="Pretty-print messages (`text` fo", comp-class-is-frozen=1, comp-class-so-handle-addr=0x55eab7ebd910, comp-class-so-handle-path="/root/workspace/joraj_integration_base_job/deps-64/build/lib/babeltrace2/plugins/babeltrace-plugin-text.so", comp-input-port-count=1, comp-output-port-count=0
02-28 16:55:03.262 32362 32362 E CLI cmd_run@babeltrace2.c:2548 Graph failed to complete successfully
ERROR: [Babeltrace CLI] (babeltrace2.c:2548)
Graph failed to complete successfully
CAUSED BY [libbabeltrace2] (graph.c:473)
Component's "consume" method failed: status=ERROR, comp-addr=0x55eab7eb0760,
comp-name="pretty", comp-log-level=WARNING, comp-class-type=SINK,
comp-class-name="pretty", comp-class-partial-descr="Pretty-print messages
(`text` fo", comp-class-is-frozen=1, comp-class-so-handle-addr=0x55eab7ebd910,
comp-class-so-handle-path="/root/workspace/joraj_integration_base_job/deps-64/build/lib/babeltrace2/plugins/babeltrace-plugin-text.so",
comp-input-port-count=1, comp-output-port-count=0
CAUSED BY [libbabeltrace2] (iterator.c:864)
Component input port message iterator's "next" method failed:
iter-addr=0x55eab7eb0fb0, iter-upstream-comp-name="muxer",
iter-upstream-comp-log-level=WARNING, iter-upstream-comp-class-type=FILTER,
iter-upstream-comp-class-name="muxer",
iter-upstream-comp-class-partial-descr="Sort messages from multiple inpu",
iter-upstream-port-type=OUTPUT, iter-upstream-port-name="out", status=ERROR
CAUSED BY [muxer: 'filter.utils.muxer'] (muxer.c:991)
Cannot validate muxer's upstream message iterator wrapper:
muxer-msg-iter-addr=0x55eab7eb1120,
muxer-upstream-msg-iter-wrap-addr=0x55eab7eb3a70
CAUSED BY [muxer: 'filter.utils.muxer'] (muxer.c:454)
Upstream iterator's next method returned an error: status=ERROR
CAUSED BY [libbabeltrace2] (iterator.c:864)
Component input port message iterator's "next" method failed:
iter-addr=0x55eab7eb1170, iter-upstream-comp-name="lttng-live",
iter-upstream-comp-log-level=WARNING, iter-upstream-comp-class-type=SOURCE,
iter-upstream-comp-class-name="lttng-live",
iter-upstream-comp-class-partial-descr="Connect to an LTTng relay daemon",
iter-upstream-port-type=OUTPUT, iter-upstream-port-name="out", status=ERROR
CAUSED BY [lttng-live: 'source.ctf.lttng-live'] (lttng-live.c:1665)
Error preparing the next batch of messages:
live-iter-status=LTTNG_LIVE_ITERATOR_STATUS_ERROR
CAUSED BY [lttng-live: 'source.ctf.lttng-live'] (viewer-connection.c:1706)
Error receiving get new streams reply
CAUSED BY [lttng-live: 'source.ctf.lttng-live'] (viewer-connection.c:198)
Remote side has closed connection
Looking at the relay daemon logs, we see the following error:
DBG1 - 16:55:03.
262106718 [32139/32146]: Adding new file "ust/pid/gen-ust-events-32373-
20220228-165503/chan_0" to trace chunk "(unnamed)" (in lttng_trace_chunk_add_file() at trace-chunk.cpp:1310)
PERROR - 16:55:03.
262133333 [32139/32146]: Failed to open fs handle to ust/pid/gen-ust-events-32373-
20220228-165503/chan_0, open() returned: No such file or directory (in fd_tracker_open_fs_handle() at fd-tracker/fd-tracker.cpp:548)
Cause
=====
Adding more debugging logging allows us to see the following situation
takes place:
- relay thread: Create trace chunk on session 1.
- live thread: get new streams against session 1, returns NO_NEW_STREAMS
since the session has an 'ongoing_rotation'.
- live thread: get new streams against session 2, sees no rotation
ongoing and attempts to open `chan_0` when creating a viewer stream
The "ongoing rotation" check was introduced in
a7ceb342d and, in a
nutshell, prevents live viewers from creating new viewer streams during
a rotation.
The "ongoing rotation" state is entered when a CREATE_NEW_TRACE_CHUNK
command is issued against a session.
However, this presumes that a relay_session maps 1:1 to a session on the
session daemon's end. This isn't the case as, in multi-domain
scenarios (tracing 32-bit, 64-bit, and kernel events), a single session
daemon session can map to multiple relay_session objects. This is
because the consumer daemons maintain independant connections to the
relay daemon.
To synchronize rotations accross related relay_session instances, the
relay daemon uses the same trace chunk instances accross relay_session
instances. This means that while a trace chunk is created against a
specific relay session, it can be used by other relay_session instances.
To manage shared trace chunks between relay_sessions, the relay daemon
makes use of the trace_chunk_registry. This registry allows
relay_sessions to share trace chunk instances using a unique key tuple:
- session daemon instance uuid,
- session daemon session id,
- trace chunk id.
There is no equivalent mechanism to track the "ongoing_rotation" state
accross relay_sessions originating from the same sessiond session.
In the current scenario, this causes the live client to correctly see
that no new streams are available for session 1 (say, the 32-bit user
space session). Unfortunately, this state is not entered for other
sessions (64-bit and kernel relay sessions). Hence, the viewer succeds
in acquiring new streams from session 2, exposing the race the 'ongoing
rotation' state aims to protect against.
Solution
========
Like the trace chunk instances, the "ongoing rotation" state must be
shared accross relay sessions that originate from the same session
daemon session.
To "emulate" this shared state, session_has_ongoing_rotation() checks
if any relay session originating from the same sessiond session
have an ongoing rotation. If it is the case, we temporarily prevent
live viewers from acquiring new streams.
Known drawbacks
===============
session_has_ongoing_rotation() iterates over all sessions, acquiring
their lock in the process, which is certainly undesirable from a
performance standpoint.
Optimizing this is not a great challenge, but is beyond the scope
of this immediate fix.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I457a32fa497d151ca933c25433c80665268a7c1c
Jonathan Rajotte [Mon, 14 Feb 2022 16:23:28 +0000 (11:23 -0500)] 
Fix: rotation: hang on destroy when using scheduled rotation based on timer
Observed issue
==============
The following scenario results in a hang for `lttng destroy`:
lttng create test
lttng enable-event -u -a
lttng enable-rotation --timer 100000
lttng start
lttng stop
lttng start
lttng destroy
Cause
=====
There is an imbalance in how many times we start the rotation timer.
The rotation timer is only removed on `lttng destroy` or when disabling
a time-based-rotation. On the other hand, the timer is "started"
on `lttng start` and when enabling a time based rotation.
The imbalance emerging from a start/stop/start sequence would prevent the
teardown of the session object since each time the timer is started a
reference to the session is held.
Solution
========
Do not start the rotation schedule timer if it was already launched.
Known drawbacks
=========
None.
Change-Id: Ic5b8938166358fe7629187bebdf02a09e90846c0
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Jonathan Rajotte [Wed, 9 Feb 2022 19:23:18 +0000 (14:23 -0500)]
Fix: consumerd: fd still open after `lttng snapshot record` returns
Observed issue
=====
Using a snapshot output located on a pramfs mount:
lttng snapshot record
rm -rf /my_mount/my_trace_output
`rm` fails with ENOTEMPTY on rmdir for /my_mount/my_trace_output.
At that point, the lttng-consumerd daemon have an open fd on:
/my_mount/my_trace_output/ust
Note that a sleep between both command "fixes" the issue.
Cause
=====
The reclaim for the in-registry trace chunks can happen after the LTTng
CLI returns since we use `call_rcu`.
```
static
void lttng_trace_chunk_release(struct urcu_ref *ref)
....
if (chunk->in_registry_element) {
struct lttng_trace_chunk_registry_element *element;
element = container_of(chunk, typeof(*element), chunk);
if (element->registry) {
rcu_read_lock();
cds_lfht_del(element->registry->ht, &element->trace_chunk_registry_ht_node);
rcu_read_unlock();
-> call_rcu(&element->rcu_node, free_lttng_trace_chunk_registry_element);
} else {
```
The delayed reclaim of the `lttng_trace_chunk_registry_element` can
result in lttng-consumerd holding an open fd for the "chunk directory"
of the chunk since the close() is only done during the "*fini" phase of
the chunk (`lttng_trace_chunk_fini`).
Solution
========
Considering that the rcu lookup+refcount access scheme is used for the
trace chunk object and that at that point the refcount for the trace
chunk object is effectively zero, we can move the
`lttng_trace_chunk_fini` safely outside of the
`free_lttng_trace_chunk_registry_element` call_rcu call.
Known drawbacks
=========
Even if this solves the current situation, it is important to note that
the actual object holding the reference is itself refcounted and only
close the fd on release. This means that we are still exposed to this
problem if at some point the directory handle is shared and outlives the
trace chunk for some reason in the future.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6da3948824bf8b092fc8248b1bb0263fdd5887be
Jonathan Rajotte [Wed, 2 Mar 2022 15:50:16 +0000 (10:50 -0500)]
Fix: event: unchecked return value for lttng_strncpy
Reported by Coverity:
CID
1475806: Unchecked return value (CHECKED_RETURN)
Calling lttng_strncpy without checking return value.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib2b16bef61bcc24fea381c18fd8f914e9a84a6e7
Jonathan Rajotte [Wed, 2 Mar 2022 15:36:11 +0000 (10:36 -0500)]
Fix: event: format specifier for ssize_t
Observed issue
==============
In file included from event.cpp:15:
event.cpp: In function ‘ssize_t lttng_event_create_from_payload(lttng_payload_view*, lttng_event**, lttng_event_exclusion**, char**, lttng_bytecode**)’:
../../src/common/error.h:191:28: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘ssize_t’ {aka ‘int’} [-Wformat=]
191 | __lttng_print(PRINT_WARN, "Warning: " fmt "\n", ## args)
| ^~~~~~~~~~~~~~~~~~~~
../../src/common/error.h:139:51: note: in definition of macro ‘__lttng_print’
139 | fprintf((type) == PRINT_MSG ? stdout : stderr, fmt, ## args); \
| ^~~
event.cpp:624:4: note: in expansion of macro ‘WARN’
624 | WARN("Userspace probe location from the received buffer is not the advertised length: header length = %" PRIu32 ", payload length = %lu", event_comm->userspace_probe_location_len, ret);
| ^~~~
Solution
========
Albeit there is no "canonical" way of printing ssize_t, use '%zd' since
we already make use of it elsewhere.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id41e6ccf07bd580813f169b65d281a4fa305fb48
Jonathan Rajotte [Wed, 2 Mar 2022 15:24:29 +0000 (10:24 -0500)]
Fix: sessiond: use after free
Introduced by
88b02a8e7cbdbc728cc681cd07bbe0c738964717
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9b1c3eeed7e51976af1a4982fc522066b3b29461
Jonathan Rajotte [Tue, 1 Mar 2022 15:35:44 +0000 (10:35 -0500)]
Fix: sessiond: `break` used instead of `goto`
On error path, use `goto`.
Reported by Coverity:
CID
1475805: Unused value (UNUSED_VALUE)
Assigning value LTTNG_ERR_UNK to ret_code here, but that stored value is overwritten before it can be used.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ife3b5486b8463242dfecb61a3a9718e8eb7149b4
Jonathan Rajotte [Tue, 1 Mar 2022 15:31:33 +0000 (10:31 -0500)]
Fix: sessiond: lttng_channel object is not reclaimed
The reclaim is also missing on the error path.
Reported by Coverity:
CID
1475807: Resource leak (RESOURCE_LEAK)
Variable channel going out of scope leaks the storage it points to.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9ae59900f6bc33282b8b8a65b834a718428a7f50
Jonathan Rajotte [Tue, 1 Mar 2022 15:27:37 +0000 (10:27 -0500)]
Fix: common: local_attr might leak
Reported by Coverity:
CID
1475808: Resource leak (RESOURCE_LEAK)
Variable local_attr going out of scope leaks the storage it points to.
CID
1475810: Resource leak (RESOURCE_LEAK)
Variable local_attr going out of scope leaks the storage it points to.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ibe2ee6516618827b6f52676d9a9f7d510cadf1bc
Jonathan Rajotte [Tue, 1 Mar 2022 15:23:24 +0000 (10:23 -0500)]
Fix: session: end goto label used for error path
Reported by Coverity:
CID
1475801: Unused value (UNUSED_VALUE)
Assigning value LTTNG_ERR_FATAL to ret_code here, but that stored value is overwritten before it can be used
CID
1475802: Unused value (UNUSED_VALUE)
Assigning value LTTNG_ERR_NOMEM to ret_code here, but that stored value is overwritten before it can be used.
CID
1475814: Unused value (UNUSED_VALUE)
Assigning value LTTNG_ERR_UST_CHAN_NOT_FOUND to ret_code here, but that stored value is overwritten before it can be used.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I79fb5d65ea0f4f3dfbbef2a42ec3dcf0542043c5
Jonathan Rajotte [Tue, 1 Mar 2022 15:18:46 +0000 (10:18 -0500)]
Fix: sessiond: event, filter expression, bytecode, exclusions might leak
Reported by Coverity:
CID
1475803: Resource leak (RESOURCE_LEAK)
Variable filter_expression going out of scope leaks the storage it points to.
CID
1475816: Resource leak (RESOURCE_LEAK)
Variable exclusions going out of scope leaks the storage it points to.
CID
1475817: Resource leak (RESOURCE_LEAK)
Variable bytecode going out of scope leaks the storage it points to.
CID
1475820: Resource leak (RESOURCE_LEAK)
Variable event going out of scope leaks the storage it points to.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I705e3cc1a1894af52d6ddeee94798a887dc82bba
Jonathan Rajotte [Tue, 1 Mar 2022 14:52:21 +0000 (09:52 -0500)]
Fix: lttng-sessiond: event_context might leak
If the parsing completed but is not the expected size, the
*out_event_context object leaks.
Reported by Coverity:
CID
1475821 (#1 of 1): Resource leak (RESOURCE_LEAK)
Variable event_context going out of scope leaks the storage it points to.
Change-Id: I8198f7f3f1e1af3dcb377d89674402ec49cb788b
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Jonathan Rajotte [Tue, 1 Mar 2022 14:09:04 +0000 (09:09 -0500)]
Fix: lttng-ctl: uninitialized pointer read
Reported by Coverity:
CID
1475822: Uninitialized pointer read (UNINIT)
Using uninitialized value reply._fd_handles.array.size when calling lttng_payload_reset.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ied7f5de61d736e8d8f9c869a36322262a4d79cd5
Jonathan Rajotte [Tue, 1 Mar 2022 14:03:45 +0000 (09:03 -0500)]
Fix: lttng-sessiond: nb_events is uninitialized
Reported by Coverity:
CID
1475823: Uninitialized scalar variable (UNINIT)
Using uninitialized value nb_events.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I623b1ed0c1ef9b4acddb1e46e7311dfcdc974629
Jonathan Rajotte [Tue, 1 Mar 2022 14:50:06 +0000 (09:50 -0500)]
Fix: ser/des: missing null terminator on payload append
Reported by the lttng-ust-java-tests_master_build CI job.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I47b048c65a9855347c9b02fe44d9fdbae7e06dbf
Jonathan Rajotte [Tue, 1 Mar 2022 17:33:53 +0000 (12:33 -0500)]
Fix: test: test plan/skip must come after TAP initialization
TAP is initialized during the sourcing of `utils.sh`. Calling it before
yield nothing.
Move the platform validation after the `PLAN_TEST` call.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib7b4434440ed7590b39b0580ea294045ace40495
Jonathan Rajotte [Tue, 1 Mar 2022 02:30:44 +0000 (21:30 -0500)]
Fix: test: missing test plan for non-x86/arm platforms (i.e powerpc)
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9a34a0b45fd011943436ce6e45c8f0d1666df26f
Jonathan Rajotte [Tue, 1 Mar 2022 02:23:53 +0000 (21:23 -0500)]
Fix: remove debugging output
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I7bcdb7c47f811cf99dee1e4e483cc22847f481c5
Jérémie Galarneau [Wed, 23 Feb 2022 22:40:06 +0000 (17:40 -0500)]
Fix: lttng: truncated addresses and offsets on 32-bit builds
The lttng client parses hexadecimal addresses using, at some point,
strtoul(). Using this function effectively caps addresses and
offsets to MAX_UINT32 resulting in failures to enable kprobes
against a 64-bit kernel using a 32-bit client.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: If619e9e84413de5cd32d8c06f363152caaf5ac46
Jonathan Rajotte [Wed, 12 Jan 2022 23:18:08 +0000 (18:18 -0500)]
Fix: liblttng-ctl comm: lttng_event_field is not packed
Observed issue
==============
For MI testing where the lttng-sessiond is 64 bit and the lttng CLI is
32 bit, the tracepoint field listing fails with partial garbage output.
The size of the struct differs between bitness for x86-64 and x86
leading to serialization/deserialization problem across client
(liblttng-ctl) and lttng-sessiond.
sizeof(struct lttng_event_field):
x86: 1136
x86-64: 1144
The struct cannot be marked as LTTNG_PACKED since it is part of the API.
Solution
========
Adopt a similar pattern to the new APIs with a "serialize" &
"create_from_buffer" approach. The only particularity is that we need to
flatten the event_field on listing.
Most of the complexity is moved to `src/common/event.c`
Known drawbacks
=========
None.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I280d9809d110237574e2606ee93a7aeba41e704e
Jonathan Rajotte [Wed, 12 Jan 2022 23:18:08 +0000 (18:18 -0500)]
Fix: liblttng-ctl comm: lttng_event_context is not packed
Observed issue
==============
The size of the struct differs between bitness for x86-64 and x86
leading to serialization/deserialization problem across client
(liblttng-ctl) and lttng-sessiond.
sizeof(struct lttng_event_context):
x86: 308
x86-64: 312
The struct cannot be marked as LTTNG_PACKED since it is part of the API.
Solution
========
Adopt a similar pattern to the new API with a "serialize" &
"create_from_buffer" approach.
Most of the complexity is moved to `src/common/event.c`
Known drawbacks
=========
None.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ieb400eab2a2df4070ff51cb2b44929d3ea945ce4
Jonathan Rajotte [Wed, 12 Jan 2022 23:18:08 +0000 (18:18 -0500)]
Fix: liblttng-ctl comm: lttng_event is not packed
Observed issue
==============
In `lttcomm_session_msg` the lttng_event struct is marked as
LTTNG_PACKED. This statement have no effect as explained in commit [2].
Solution
========
Adopt a similar pattern to the new API with a "serialize" &
"create_from_buffer" approach.
Most of the complexity is moved to `src/common/event.c`
Known drawbacks
=========
None.
Note
====
Jérémie Galarneau: This patch was extensively modified from the original
patch applying against stable-2.12 to accomodate for the use of the
lttng_payload utils throughout the liblttng-ctl <-> lttng-sessiond
communication code.
Some changes were also made to build as C++.
Reference
========
[1] https://review.lttng.org/gitweb?p=lttng-tools.git;a=commit;h=
7bd95aee4660c6419a4a65429fc27754481e7e90
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I35d848519dacb2b119324e88f262aa95951e4ac6
Jonathan Rajotte [Sat, 29 Jan 2022 00:29:58 +0000 (19:29 -0500)]
libcommon: move event.c to libcommon-lgpl
The `event.c` license is already LGPL. There is no technical reason why
it was not part of the lgpl side of libcommon, simply that nothing that
is LGPL needed it. This will change in upcoming commits with the
addition of ser/des functions of `struct lttng_event` and other structs
related to `lttng_event` for liblttng-ctl.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I1e15a547e526198f971a287a726d0e6229a733b0
Jonathan Rajotte [Wed, 12 Jan 2022 23:18:08 +0000 (18:18 -0500)]
Fix: liblttng-ctl comm: lttng_channel is not packed
Observed issue
==============
The size of the struct differs between bitness for x86-64 and x86
leading to serialization/deserialization problem across client
(liblttng-ctl) and lttng-sessiond.
sizeof(struct lttng_channel):
x86: 608
x86-64: 624
The struct cannot be marked as LTTNG_PACKED since it is part of the API.
Solution
========
Adopt a similar pattern to the new API with a "serialize" &
"create_from_buffer" approach. The only particularity is that we need to
flatten the channels on listing.
Most of the complexity is moved to `src/common/channel.c`
Known drawbacks
=========
None.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id5c9aaf3cf8b3d739b71263c02cae8d4d2fedfe3
Jonathan Rajotte [Thu, 27 Jan 2022 19:22:22 +0000 (14:22 -0500)]
Fix: conversion from KB to bytes overflow on arm32
Observed issue
==============
On enable channel the memory available check fails on arm32 when
available memory, in bytes, is larger than 2^32.
Cause
=====
`read_proc_meminfo_field` converts the read value (in KB) to bytes and
stores it into a size_t variable.
On the system running the reproducer the value of the `value_kb` variable
is
4839692, yielding an overflow when multiplied with 1024 since
`size_t` is 32 bit long. `size_t` can be larger in certain situation
(i.e LARGEFILE) but this is irrelevant to the problem at hand.
Solution
========
Convert all the checks to use uint64_t.
Known drawbacks
=========
None.
References
==========
The multiplication overflow check scheme is borrowed from
`src/common/time.c`
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I067da25659ab4115e5494e48aab45a1c35f56652
Jonathan Rajotte [Tue, 11 Jan 2022 17:28:15 +0000 (12:28 -0500)]
Fix: Unexpected payload size in cmd_recv_stream_2_11
Observed issue
==============
For the following scenario:
lttng-relayd: 64 bit
lttng-sessiond: 64 bit
lttng-consumerd: 32 bit
application: 32 bit
Commands
lttng create --set-url=net://127.0.0.1
lttng enable-event -u -a
lttng start
./application
On application start the lttng-relayd reports this error:
DEBUG1 - 14:16:38.
216442600 [
2004731/
2004735]: Done receiving control command payload: fd = 19, payload size = 4376 bytes (in relay_process_control_receive_payload() at main.c:3456)
DEBUG3 - 14:16:38.
216469462 [
2004731/
2004735]: Processing "RELAYD_ADD_STREAM" command for socket 19 (in relay_process_control_command() at main.c:3327)
Error: Unexpected payload size in "cmd_recv_stream_2_11": expected >=
3519925694 bytes, got 4376 bytes
Cause
=====
In `relayd_add_stream`, instead of taking the > 2.11 protocol path, the
`relayd_add_stream_2_2` function is called.
The value of the rsock version number are:
major: 21845
minor: 2
Which is simply invalid since we know that the version should be 2.12.
The relayd sock version numbers are set during the
LTTNG_CONSUMER_ADD_RELAYD_SOCKET command between the lttng-sessiond and
the lttng-consumerd process. It is important to note here that both
processes do NOT have the same bitness.
The serialization and deserialization of `struct lttcomm_relayd_sock` is
the culprit.
`struct lttcomm_relayd_sock` contains a `struct lttcomm_sock`:
struct lttcomm_sock {
int32_t fd;
enum lttcomm_sock_proto proto;
struct lttcomm_sockaddr sockaddr;
const struct lttcomm_proto_ops *ops;
} LTTNG_PACKED;
Note that `ops` is a pointer and its size varies based on the bitness of
the application. Hence the size of the `struct lttcomm_sock` differs
across bitness. Since it is the first member of `struct
lttcomm_relayd_sock`, the memory layout is simply invalid across
bitness (amd64/x86).
This results in invalid parsing for the overall "struct
lttcomm_relayd_sock" when dealing with a lttng-consumerd with a
different bitness than the lttng-sessiond. As far as I know local
tracing scenarios are not affected since this is only relevant when
dealing with a lttng-relayd.
Solution
========
Pass the socket protocol type, relayd major, relayd minor in
`lttcomm_consumer_msg`. On the receiver side, query the network stack to
get the peer information to populate a basic `lttcomm_sock`. Leaving
this work to the OS saves us from having to serialize the `sockaddr_in*`
structs.
Known drawbacks
=========
We rely on `getpeername` for the first time. Compatibility might be a
problem.
This code path assumes a lot of thing that cannot be asserted against
such as the fact that the socket from which we fetch the info must be
`connected`. Still at this point, the socket is completely setup and the
rest of the code depends on it already.
From GETPEERNAME(2):
```
For stream sockets, once a connect(2) has been performed, either
socket can call getpeername() to obtain the address of the peer
socket. On the other hand, datagram sockets are connectionless.
Calling connect(2) on a datagram socket merely sets the peer
address for outgoing datagrams sent with write(2) or recv(2).
The caller of connect(2) can use getpeername() to obtain the
peer address that it earlier set for the socket. However, the
peer socket is unaware of this information, and calling
getpeername() on the peer socket will return no useful
information (unless a connect(2) call was also executed on the
peer). Note also that the receiver of a datagram can obtain the
address of the sender when using recvfrom(2).
```
But here we are always "the caller of connect".
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic157c4137b2f20e394c907136687fcbd126f90a0
Jonathan Rajotte [Mon, 31 Jan 2022 19:47:35 +0000 (14:47 -0500)]
Tests: add kernel test into the `make check` test suite.
The Jenkins CI mostly run the `make check` suite. Only the Lava base CI
run the root_regression test suite. Most of those test can be run on
`make check` without incurring any major extra time.
Only `regression/tools/streaming/test_high_throughput_limits` is left in
root_regression since it is currently "unreasonable" in term of the time
it takes to run. This could be tackled another time.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3d59705e84549c2a1840cf96a7723396e2e0c402
Jérémie Galarneau [Wed, 9 Feb 2022 00:41:10 +0000 (19:41 -0500)]
Build dist fix: some kernel tests are not distributed
A missing '\' causes some kernel test scripts to not be added
the EXTRA_DIST variable. This causes those tests to not be
shipped as part of the tarball.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3c824b4c7ea913cb4cdc7ac6f98df05267ca5764
Jérémie Galarneau [Thu, 10 Feb 2022 22:53:56 +0000 (17:53 -0500)]
Tests: fix: test_kernel_function: erroneous test count
The test_kernel_function test runs one extra test which causes it to be
marked as failed. Adjust the count to fit the number of tests.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ia861cf7b0123fdf19405bb84271ddda76f9fd6e7
Jérémie Galarneau [Wed, 9 Feb 2022 22:00:40 +0000 (17:00 -0500)]
Tests: fix: test_kernel_function: event name mismatch
The test_kernel_function test expects the name of the function
exit event to be suffixed with "_return". This was changed to
"_exit" during the development of the 2.13 release.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6e7f85af33699b2bf0439f74343d521f896594e1
Jérémie Galarneau [Thu, 10 Feb 2022 16:59:31 +0000 (11:59 -0500)]
Tests: fix: select_poll_epoll: test assumes epoll fd value
The test currently assumes that epoll fds are always == 3, which
is not always the case depending on the execution environment.
This change causes `select_poll_epoll` to produce a JSON file
containing the application's pid and epoll fd values that is
then used by the validation script.
Note that the test is converted to C++ to allow the use of
internal utils (common/error.h/cpp) without changing their linkage.
However, the code is still regular C to ease the backport of this
fix.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie373c63f6e6b9267ae2d785c9f0a532a5de37905
Jérémie Galarneau [Thu, 24 Feb 2022 19:06:28 +0000 (14:06 -0500)]
Fix: tests: test_kernel: break should only be used in loops
Using `break` in a function's scope makes no sense in bash. I am
guessing the original author meant to exit early from the various tests.
Regardless, the rest of the test can be ran without issues. I am not
sure traces of failed tests should be kept, but that's a separate issue.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I286ccb796afbbca4e3866e6fd0b35a3746045346
Jérémie Galarneau [Thu, 24 Feb 2022 19:05:16 +0000 (14:05 -0500)]
Tests: test_kernel: add comments regarding the filling of buffers
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3a8652d7dd95c015d6978349d166e8f291c9a5f3
Mathieu Desnoyers [Thu, 24 Feb 2022 17:24:45 +0000 (12:24 -0500)] 
Fix: tools/snapshots/test_kernel flaky test
When tracing all system calls, nothing guarantees that the first system
call won't come from some _other_ program on the system, on a CPU != 0,
and stay invariant between the two snapshots (when it should not be).
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iba45664f10eea0a757f8ac4eb9a7c7c75c305eef
Francis Deslauriers [Thu, 25 Mar 2021 17:13:45 +0000 (13:13 -0400)] 
Tests: Fix: test_list_triggers_cli: support in-kernel builtin lttng-modules
This commit changes the grep call to remove the [lttng_tracer] string
from the pattern. When building the lttng modules directly in the kernel
there is not mention of [lttng_tracer].
Furthermore, the symbol type "t" is "T" in my test VM. The difference
may be due to the builtin nature of lttng on this VM.
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I046905dc51524c23ad3671b66614b86a084ef8e2
Depends-on: lttng-ust: If1f29dd64538bc5979d3e89aa5cca3be4e41046f
Michael Jeanson [Fri, 11 Feb 2022 15:26:02 +0000 (15:26 +0000)] 
Add Log4j 2.x agent tests for the 'log4j' domain
Add integration tests for the new Log4j 2.x agent in Log4j 1.x compat
mode using the current 'log4j' domain, use the new configure switch
'--enable-test-java-agent-log4j2' to enable it or
'--enable-test-java-agent-all' to enable all Java agents tests.
To run only this new test, use this command :
cd tests/regression && make check TESTS="ust/java-log4j2/test_agent_log4j2_domain_log4j"
Change-Id: Id780c9ee13913c91c18548f58b14cc600e77e9fa
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Michael Jeanson [Fri, 19 Nov 2021 20:40:09 +0000 (15:40 -0500)]
src/common: use single Makefile for parallel builds
Use a single Makefile in 'src/common' as it contains multiple
subdirectories with a small number of objects to compile. This allows
faster parallel builds since parallelism in automake is applied per
Makefile.
There is anectodal evidence of a 25 seconds improvement to the build
process on a 36 core machine.
Change-Id: If2ce266050e345d58b00bf65b574ccf5168f28f1
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Francis Deslauriers [Mon, 27 Sep 2021 18:01:04 +0000 (14:01 -0400)]
Fix: missing RCU read side critical sections
Based on the comments of the called functions.
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ica81b648ce88290c4ca7507fb00a78480457cf01
Francis Deslauriers [Mon, 27 Sep 2021 14:56:28 +0000 (10:56 -0400)]
Enforce documented RCU preconditions with assertions
Mindlessly add `rcu_read_ongoing()` assertions to functions that are
documented as "must be called" within a RCU critical section.
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I25f9903938123394e6960ab2a338be6abaf2fe72
Francis Deslauriers [Tue, 18 Jan 2022 22:25:06 +0000 (17:25 -0500)]
Remove ht-cleanup thread
The hashtable cleanup thread was introduced to prevent deadlocks
happening when the `cds_lfht_destroy()` function was called concurrently
with userspace-rcu hashtable resizes.
This was fixed in the userspace-rcu project in commit:
commit
d0ec0ed2fcb5d67a28587dcb778606e64f5b7b83
Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Tue May 30 15:51:45 2017 -0400
Use workqueue in rculfhash
That commit makes it so that the `cds_lfht_destroy()` function can
safely be called within RCU read-side critical sections.
This commit is included in the 0.10 release of urcu. The LTTng-Tools
project now has a minimum version dependency on urcu 0.11.
Because it's now safe to call `cds_lfht_destroy()` within RCU critical
sections, the need for the hash table cleanup thread disappears. This
commit replaces all uses of `ht_cleanup_push()` by `lttng_ht_destroy()`
and remove all uses and mentions of the ht_cleanup thread.
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I163a281b64a6b3eed62c58515932f71f3b52fea6
Francis Deslauriers [Wed, 20 Jan 2021 21:18:09 +0000 (16:18 -0500)]
Cleanup: remove outdated comments on RCU requirements
The ht-cleanup thread was introduced to work-around the limitation that
the hash table destroy could not be called from a RCU read-side critical
section because of requirements from the rculfhash API, some comments
stating that destruction code should not be called from RCU read-side
critical sections were left in place when they should in fact have been
removed.
This ht-cleanup thread work around was introduced by the following
commit:
commit
0b2dc8df2a6d7b3341a72a04767dd6328907c97c
Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Fri Jun 14 07:44:52 2013 -0400
Fix: hash table cleanup call_rcu deadlock
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ifdaa63e6146b51fdb251e75795e382b5f390f7be
Francis Deslauriers [Thu, 18 Nov 2021 20:11:58 +0000 (15:11 -0500)]
relayd: add logging statements in `viewer_get_packet()`
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Idf3c7a5e87636abe63ff59d22bb3104f1d3519e5
Francis Deslauriers [Thu, 18 Nov 2021 17:57:22 +0000 (12:57 -0500)]
relayd: add logging statements in `viewer_attach_session()`
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2cdae4bd809442d5de7dcfb838f346e1e4370628
Francis Deslauriers [Tue, 16 Nov 2021 20:14:57 +0000 (15:14 -0500)]
relayd: add logging statements in `viewer_get_next_index()`
Change the byte order of the `status` field right before we send the
index to the viewer to allow for useful logging along the way.
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I50bb246810486e13fde3085e21fea4bb5ef3776b
Mathieu Desnoyers [Wed, 26 Jan 2022 15:53:55 +0000 (10:53 -0500)]
Fix: _lttng_variant_statedump should expect lttng_ust_ctl_atype_variant_nestable
The precondition check in _lttng_variant_statedump is too strict: it
should also expect lttng_ust_ctl_atype_variant_nestable. Remove this
check entirely, which is redundant with the switch/case in the only
caller sites in the same compile unit.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I744cc5cef69ff29f8d7ecc1cf01c9a629c6e222e
Mathieu Desnoyers [Mon, 24 Jan 2022 22:05:39 +0000 (17:05 -0500)]
Fix context mismatch across UST version due to legacy array context field
Observed issue
==============
Tracing applications linked against both LTTng-UST 2.12.x and 2.13.1 in
the same session fails with:
"Error: Registering application channel due to context field mismatch"
for some applications with the "procname" context enabled.
Cause
=====
The procname context uses the legacy array field type prior to LTTng-UST
2.13, and uses the array_nestable field type starting from LTTng-UST
2.13. The field comparison in lttng-sessiond is unaware of the fact that
they map to the exact same binary trace layout and are therefore
compatible.
Solution
========
Introduce a new fixup function "ust_app_fixup_legacy_context_fields" in
lttng-sessiond for channel context fields, which detects the presence of
the legacy array, struct and variant types, and rewrites them as
array_nestable, struct_nestable, and variant_nestable types.
Reject the legacy sequence type in channel context fields because it is
not used by LTTng-UST 2.12 and older.
Rewriting those legacy context types as the new "nestable" types ensures
that field comparison functions will correctly handle a mix of 2.12 and
2.13 LTTng-UST tracers using a procname context to a given session's
channel.
Known Drawbacks
===============
None.
Fixes: fb2772932 ("Validate channel context mismatch across UST applications")
Change-Id: Ic51b92130ae8e1f7b510924f78ff46459dc2f578
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Mathieu Desnoyers [Wed, 12 Jan 2022 21:46:21 +0000 (16:46 -0500)]
Relicence all source and header files included in LGPL code
All code included in libcommon-lgpl.a should be LGPL. Some were licensed
as GPLv2 by mistake. We need to relicense those.
EfficiOS owns the copyright to all of the affected source files and
agrees to this relicensing from GPLv2 to LGPLv2.1.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib4aa1a7cc8a6f8e2a9891f1bd05c7ea2f8530e9b
Mathieu Desnoyers [Wed, 19 Jan 2022 16:35:20 +0000 (11:35 -0500)]
Move utils_expand_path and utils_expand_path_keep_symlink to libpath.la
Move the GPLv2 helper functions utils_expand_path and
utils_expand_path_keep_symlink to libpath.la. This will allow utils.cpp
to be relicensed to LGPLv2.1 by making sure EfficiOS owns the copyright
for the entire source file.
Statically include libpath.la into libcommon-gpl.la.
The "lttng" executable is GPLv2 and only depends on libcommon-lgpl.la,
so it needs to explicitly list libpath.la as its dependency.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2108e0bd35ce75797d4a20e65891c820a1dd79f8
Mathieu Desnoyers [Wed, 12 Jan 2022 20:23:09 +0000 (15:23 -0500)]
Link lttng executable on libcommon-lgpl.a
Allows testing whether liblttng-ctl.so has any dependency on
libcommon-gpl.a. Will trigger a link-time failure if it is the case.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie6f864dccdd61f896a7e238e202dc6188ec4f9c5
Mathieu Desnoyers [Tue, 11 Jan 2022 20:57:37 +0000 (15:57 -0500)]
Introduce libcommon-lgpl for liblttng-ctl
liblttng-ctl is a LGPLv2.1 library should should not use GPLv2 code.
Introduce libcommon-lgpl as a static archive containing only LGPLv2.1
compatible code.
This also removes the dependency from liblttng-ctl to liburcu.
Include some source files in libcommon-lgpl.a which are indirectly needed
by source files required in libcommon-lgpl.a:
- endpoint.cpp,
- lttng-elf.cpp,
- lttng-elf.h.
Include some source files in libcommon-lgpl.a which are only needed to
link the lttng executable:
- domain.cpp,
- spawn-viewer.cpp, spawn-viewer.h.
Introduce the new source file hashtable/seed.cpp to move the
lttng_ht_seed symbol in a source file which does not require
liburcu-cds, so it can be present in libcommon-lgpl. This allows
building compile units which are needed in the lgpl common library which
also contain functions which directly refer to lttng_ht_seed.
Programs and libraries which use libhashtable.la are changed to use
libcommon-gpl.la instead. libhashtable becomes internal to libcommon.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I27d2acb823a6d951692a5da88ce32bbe6bafb072
Mathieu Desnoyers [Tue, 11 Jan 2022 19:46:37 +0000 (14:46 -0500)]
Rename libcommon.so to libcommon-gpl.so
libcommon is a static library is currently used by both liblttng-ctl
(LGPLv2.1) and all lttng-tools executables (GPLv2).
Given that some code in libcommon depends on liburcu, this introduces an
indirect dependency from liblttng-ctl to liburcu, which is unwanted.
This first step renames libcommon.so to libcommon-gpl.so. Following
steps will introduce a more lightweight libcommon-lgpl.so which only
contains LGPLv2.1 code, and removes the dependency on liburcu.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ia8f37ea229f68550200cbb1528216a505bbbd45f
Mathieu Desnoyers [Thu, 20 Jan 2022 15:30:01 +0000 (10:30 -0500)]
Copyright ownership transfer
Apply copyright ownership transfer from Jonathan Rajotte-Julien and
Olivier Cotte to EfficiOS Inc.
Link: https://lists.lttng.org/pipermail/lttng-dev/2022-January/030111.html
Link: https://lists.lttng.org/pipermail/lttng-dev/2022-January/030113.html
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Olivier Moussavou Cotte <olivier.moussavoucotte@mail.mcgill.ca>
Signed-off-by: Jonathan Rajotte-Julien <jonathan.r.julien@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I0c2800ec17f5d435c8a18f2dae096809b8037b5d
Jérémie Galarneau [Wed, 19 Jan 2022 19:35:25 +0000 (14:35 -0500)]
Docs: relayd: live: clarify ownership of vstream after viewer release
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2b0a838bb72bec1ec693ee0c722b748105d7280c
Jérémie Galarneau [Fri, 14 Jan 2022 20:42:03 +0000 (15:42 -0500)]
Copyright ownership transfer
Apply copyright ownership transfer from David Goulet, Julien Desfossez,
and Simon Marchi to EfficiOS Inc.
Link: https://lists.lttng.org/pipermail/lttng-dev/2022-January/030087.html
Link: https://lists.lttng.org/pipermail/lttng-dev/2022-January/030092.html
Link: https://lists.lttng.org/pipermail/lttng-dev/2022-January/030091.html
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Signed-off-by: David Goulet <dgoulet@ev0ke.net>
Signed-off-by: Julien Desfossez <ju@klipix.org>
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Change-Id: Id13575afd4a2a09bb91a8d2b7a12dc3db8dc329f
Jérémie Galarneau [Fri, 23 Jul 2021 20:56:53 +0000 (16:56 -0400)]
Fix: relayd: erroneous rundir permission logging message
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2eb0901896feab684d397aa43f8c9036018d9c95
Jérémie Galarneau [Thu, 9 Dec 2021 21:27:29 +0000 (16:27 -0500)]
Fix: sessiond: rotation thread: fatal error when not finding a session
The rotation thread implements scheduled rotations (by size) by
registering a trigger that monitors the session's consumed size and
notifies when the next rotation's size threshold is exceeded.
The notification is delivered asynchronously which doesn't prevent
the session from being destroyed before the rotation thread has
had the time to process the notification (and perform a rotation).
Since it is possible for a session to be destroyed by the time the
notification is processed, the rotation thread shouldn't handle
this eventuality as a fatal error (shutting down the thread).
Note that nobody reported this issue nor did I attempt to reproduce it.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I588054bad3542854851f28d34f2c758bdf420a34
Jérémie Galarneau [Wed, 12 Jan 2022 20:48:00 +0000 (15:48 -0500)]
Fix: relayd: rotation failure for multi-domain session
Observed issue
==============
Rotating a multi-domain streaming session results in the following
error:
$ lttng rotate
Waiting for rotation to complete...
Error: Failed to retrieve rotation state.
Meanwhile, the relay daemon logs indicate the following:
DBG1 - 14:56:04.
213163667 [265774/265778]: lttng_trace_chunk_rename_path from .tmp_new_chunk to (null) (in lttng_trace_chunk_rename_path_no_lock() at trace-chunk.cpp:759)
PERROR - 14:56:04.
213242941 [265774/265778]: Failed to move trace chunk directory ".tmp_new_chunk" to "20220112T145604-0500-1": No such file or directory (in lttng_trace_chunk_rename_path_no_lock() at trace-chunk.cpp:799)
DBG1 - 14:56:04.
213396931 [265774/265778]: aborting session 2 (in session_abort() at session.cpp:588)
DBG1 - 14:56:04.
213512198 [265774/265778]: Control connection closed with 22 (in relay_thread_close_connection() at main.cpp:3874)
The 'abort' of session 2 here causes the kernel consumer to fail to
consume subbuffers:
Error: Relayd send index failed. Cleaning up relayd 3.
Error: Error consuming subbuffer: (0)
[...]
Cause
=====
Following the flow of execution in the relay daemon shows that different
trace chunks are used by the two relay sessions that result from the
streaming of a single multi-domain session. Both trace chunks "own" the
same output directory.
When a rotation is performed, the first trace chunk to be closed will
move the directory. Then, the second trace chunk to be closed will
attempt to do the same, failing to do so as seen in the relay daemon
log.
Solution
========
Using different trace chunk instances for relay sessions belonging to a
single sessiond session goes against the intended use of the sessiond
trace chunk registry.
A sessiond trace chunk registry allows the relay daemon to share trace
chunks used by different "relay sessions" when they were created for the
same user-visible session daemon session. Tracing multiple domains (e.g.
ust and kernel) results in per-domain relay sessions being created.
Sharing trace chunks, and their output directory more specifically, is
essential to properly implement session rotations. The sharing of output
directory handles allows directory renames to be performed once and
without races that would stem from from multiple renames.
The reason why sessiond trace chunk registry returns different trace
chunk instances for two relay sessions is that the wrong session `id` is
used to publish trace chunks. The `id` that must be used to share trace
chunks accross the relay sessions that belong to the same sessiond
session is `id_sessiond`.
`id_sessiond` is optional as it is only provided by consumers v2.11+.
Otherwise, it is fine to use the relay session `id`: it is a unique id
for a given session daemon instance and those consumers will not issue a
session rotation (or clear) as the feature didn't exist.
A reference counting bug revealed by this change is also fixed in the
implementation of the sessiond trace chunk registry.
When the trace chunk is first published, two references to the published
chunks exist. One is taken by the registry while the other is being
returned to the caller. In the use case of the relay daemon, the
reference held by the registry itself is undesirable.
We want the trace chunk to be removed from the registry as soon as it is
not being used by the relay daemon (through a session or a stream). This
differs from the behaviour of the consumer daemon which relies on an
explicit command from the session daemon to release the registry's
reference.
In cases where the trace chunk had already been published, the reference
belonging to the sessiond trace chunk registry instance has already been
'put' by the firt publication. We must simply return the published trace
chunk with a reference taken on behalf of the caller.
Known drawbacks
===============
None.
Change-Id: Ic33443b114a87574a1b26ac5ccb022e47f886ddd
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Jérémie Galarneau [Wed, 12 Jan 2022 17:43:07 +0000 (12:43 -0500)]
Docs: relayd: document the role of session_trace_chunk_registry
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6158dadfe92d23c0081aac888c3e54b3c9c711a3
Mathieu Desnoyers [Tue, 11 Jan 2022 18:59:15 +0000 (13:59 -0500)]
Fix: lttng-ctl: lttng_list_sessions: initialize out_sessions to NULL when returning 0
Observed issue
==============
Users of lttng-ctl API's lttng_list_sessions observe application crash
when freeing the *out_sessions output value when lttng_list_sessions
returns 0.
Cause
=====
The implementation does not set *out_sessions to NULL when
lttng_ctl_ask_sessiond() sets the sessions variable to NULL.
This causes the user application to attempt to free(3) an uninitialized
pointer.
Solution
========
Initialize out_sessions to NULL before invoking
lttng_ctl_ask_sessiond(), so it is initialized when lttng_list_sessions
returns 0, thus allowing *out_sessions to be subsequently freed.
A free(3) on a NULL pointer is a no-op.
Known drawbacks
===============
None.
History
=======
This was introduced by those two commits:
b178f53e90 ("Generate session name and default output on sessiond's end")
27ea4ba825 ("Fix: error when listing sessions with no session")
This is a regression present in the stable-2.11, stable-2.12,
stable-2.13, and master branches.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I34125d708a32674d79b831e5004c48321ebd711e
Francis Deslauriers [Thu, 18 Nov 2021 17:38:11 +0000 (12:38 -0500)]
relayd: add `lttng_viewer_command_str()`
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Icb7be4901727654c6339ed47344320140fdaf9fb
Francis Deslauriers [Thu, 11 Nov 2021 15:48:31 +0000 (10:48 -0500)]
relayd: add `lttcomm_relayd_command_str()`
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Idfd708843d19ca1b2cfe458a3b2b37e55f9c3274
Simon Marchi [Tue, 30 Nov 2021 03:15:53 +0000 (22:15 -0500)] 
Fix: lttng: initialize variable in run_command_string
I got some crashes when using `lttng track` and hitting some error
paths. The tracker_handle variable is run_command_string is passed to
lttng_process_attr_tracker_handle_destroy uninitialized if
lttng_session_get_tracker_handle fails.
$ valgrind lttng track --kernel --pid 569878
==634572== Memcheck, a memory error detector
==634572== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==634572== Using Valgrind-3.17.0 and LibVEX; rerun with -h for copyright info
==634572== Command: lttng track --kernel --pid 569878
==634572==
Error: Unknown error
==634572== Conditional jump or move depends on uninitialised value(s)
==634572== at 0x4875007: lttng_process_attr_tracker_handle_destroy (tracker.cpp:25)
==634572== by 0x13AC55: run_command_string(cmd_type, char const*, lttng_domain_type, lttng_process_attr, char const*, mi_writer*) (track-untrack.cpp:485)
==634572== by 0x13ADA5: run_command(cmd_type, char const*, process_attr_command_args const*, mi_writer*) (track-untrack.cpp:535)
==634572== by 0x13B472: cmd_track_untrack(cmd_type, int, char const**, char const*) (track-untrack.cpp:740)
==634572== by 0x13B5D9: cmd_track(int, char const**) (track-untrack.cpp:805)
==634572== by 0x14C598: handle_command(int, char**) (lttng.cpp:237)
==634572== by 0x14CCE9: parse_args(int, char**) (lttng.cpp:426)
==634572== by 0x14CE65: main (lttng.cpp:475)
Fix it by initializing it to NULL.
Change-Id: Id2693e75c3c5c83cef58db3109973d7ab679b859
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Jérémie Galarneau [Wed, 1 Dec 2021 13:46:11 +0000 (08:46 -0500)]
Fix: enable-rotation: wrong type of rotation specified in message
48a4000 changed the initialization of the schedule_type_str to allow the
code to compile as C++. The C-version of the code explicitly specified
the enum values which was "safer" while the C++ version assumes that the
array is initialized in the order of the enum's values.
This results in an incorrect message when enabling a rotation schedule.
For instance, enabling a periodic rotation will print that a
"size-based" rotation was successfully enabled.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3cb6fcb6a67d7b0fa4c7913694923b5f03255389
Simon Marchi [Wed, 8 Sep 2021 17:12:12 +0000 (13:12 -0400)]
common: replace uses of calloc(..., 1) with zmalloc
I found these uses of calloc, which could be replaced with zmalloc. I
presumed that the reason for using calloc was for the fact that it
initializes the memory to zeroes.
Change-Id: Icd8b84d707978e949c55d9694e6dbc10319c0169
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Mathieu Desnoyers [Mon, 22 Nov 2021 19:38:35 +0000 (14:38 -0500)]
Fix: consumer-stream: live viewers observe timestamps going backwards
Observed issue
==============
When stress-testing over an entire weekend, we caught the following
occurrences of timestamps going backwards with babeltrace in live viewer
mode:
One occurrence:
# Test ust streaming live clear with viewer with new metadata after clear
# Parameters: tracing_active=0, clear_twice=0, buffer_type=pid
6-7 occurrences:
# Test ust basic streaming live with viewer
# Parameters: tracing_active=1, clear_twice=0, buffer_type=uid
Relevant log of the relayd focused on the context of the stream
triggering the issue (stream 994):
506:DBG1 - 17:26:54.
966288486 [
3866648/
3866655]: Relay viewer stream 994 not found (in viewer_stream_get_by_id() at viewer-stream.cpp:268)
603:DBG1 - 17:26:54.
970265349 [
3866648/
3866655]: Sending stream 994 to viewer (in send_viewer_streams() at live.cpp:241)
843:DBG1 - 17:26:55.
959835404 [
3866648/
3866652]: stream_add_index for stream 994 (in stream_add_index() at stream.cpp:1233)
844:DBG3 - 17:26:55.
959866303 [
3866648/
3866652]: Finding index for stream id 994 and seq_num 0 (in relay_index_get_by_id_or_create() at index.cpp:112)
845:DBG2 - 17:26:55.
959896611 [
3866648/
3866652]: Creating relay index for stream id 994 and seqnum 0 (in relay_index_create() at index.cpp:34)
846:DBG2 - 17:26:55.
959928097 [
3866648/
3866652]: Adding relay index with stream id 994 and seqnum 0 (in relay_index_add_unique() at index.cpp:70)
847:DBG2 - 17:26:55.
959968163 [
3866648/
3866652]: Index found or created in HT for stream ID 994 and seqnum 0 (in relay_index_get_by_id_or_create() at index.cpp:144)
884:DBG3 - 17:26:55.
961676906 [
3866648/
3866652]: Receiving data for stream id 994 seqnum 0, 0 bytes received, 84 bytes left to receive (in relay_process_data_receive_payload() at main.cpp:3583)
885:DBG1 - 17:26:55.
961783540 [
3866648/
3866652]: Wrote to stream 994: data_length = 84, padding_length = 0 (in stream_write() at stream.cpp:1113)
886:DBG1 - 17:26:55.
961862441 [
3866648/
3866652]: Wrote to stream 994: data_length = 0, padding_length = 4012 (in stream_write() at stream.cpp:1113)
887:DBG1 - 17:26:55.
961895593 [
3866648/
3866652]: handle_index_data: stream 994 net_seq_num 0 data offset 0 (in stream_update_index() at stream.cpp:1140)
888:DBG3 - 17:26:55.
961945901 [
3866648/
3866652]: Finding index for stream id 994 and seq_num 0 (in relay_index_get_by_id_or_create() at index.cpp:112)
889:DBG2 - 17:26:55.
961983056 [
3866648/
3866652]: Index found or created in HT for stream ID 994 and seqnum 0 (in relay_index_get_by_id_or_create() at index.cpp:144)
894:DBG2 - 17:26:55.
962334285 [
3866648/
3866652]: Writing index for stream ID 994 and seq num 0 (in relay_index_try_flush() at index.cpp:275)
895:DBG2 - 17:26:55.
962390756 [
3866648/
3866652]: index put for stream id 994 and seqnum 0 refcount 1 (in relay_index_put() at index.cpp:237)
1743:DBG1 - 17:26:56.
083287172 [
3866648/
3866655]: Check index status: index_received_seqcount 1 index_sent_seqcount 0 for stream 994 (in check_index_status() at live.cpp:1454)
1746:DBG1 - 17:26:56.
083446379 [
3866648/
3866655]: Sending viewer index for stream 994 offset 0 (in viewer_get_next_index() at live.cpp:1801)
1748:DBG1 - 17:26:56.
083544877 [
3866648/
3866655]: Index 1 for stream 994 sent (in viewer_get_next_index() at live.cpp:1842)
1751:DBG1 - 17:26:56.
083778149 [
3866648/
3866655]: Sent 4108 bytes for stream 994 (in viewer_get_packet() at live.cpp:1968)
2858:DBG1 - 17:26:56.
907744916 [
3866648/
3866652]: stream_add_index for stream 994 (in stream_add_index() at stream.cpp:1233)
2859:DBG1 - 17:26:56.
907762798 [
3866648/
3866652]: Received live beacon for stream 994 (in stream_add_index() at stream.cpp:1237)
2862:DBG3 - 17:26:56.
907855597 [
3866648/
3866652]: Receiving data for stream id 994 seqnum 1, 0 bytes received, 84 bytes left to receive (in relay_process_data_receive_payload() at main.cpp:3583)
2863:DBG1 - 17:26:56.
907950195 [
3866648/
3866652]: Wrote to stream 994: data_length = 84, padding_length = 0 (in stream_write() at stream.cpp:1113)
2864:DBG1 - 17:26:56.
908002911 [
3866648/
3866652]: Wrote to stream 994: data_length = 0, padding_length = 4012 (in stream_write() at stream.cpp:1113)
2865:DBG1 - 17:26:56.
908024312 [
3866648/
3866652]: handle_index_data: stream 994 net_seq_num 1 data offset 4096 (in stream_update_index() at stream.cpp:1140)
2866:DBG3 - 17:26:56.
908043082 [
3866648/
3866652]: Finding index for stream id 994 and seq_num 1 (in relay_index_get_by_id_or_create() at index.cpp:112)
2867:DBG2 - 17:26:56.
908061879 [
3866648/
3866652]: Creating relay index for stream id 994 and seqnum 1 (in relay_index_create() at index.cpp:34)
2868:DBG2 - 17:26:56.
908082115 [
3866648/
3866652]: Adding relay index with stream id 994 and seqnum 1 (in relay_index_add_unique() at index.cpp:70)
2869:DBG2 - 17:26:56.
908101275 [
3866648/
3866652]: Index found or created in HT for stream ID 994 and seqnum 1 (in relay_index_get_by_id_or_create() at index.cpp:144)
3011:DBG1 - 17:26:56.
913436908 [
3866648/
3866655]: Check index status: index_received_seqcount 1 index_sent_seqcount 1 for stream 994 (in check_index_status() at live.cpp:1454)
3012:DBG1 - 17:26:56.
913457688 [
3866648/
3866655]: Check index status: inactive with beacon, for stream 994 (in check_index_status() at live.cpp:1492)
3014:DBG1 - 17:26:56.
913507164 [
3866648/
3866655]: Index 1 for stream 994 sent (in viewer_get_next_index() at live.cpp:1842)
3043:DBG1 - 17:26:56.
914167206 [
3866648/
3866652]: stream_add_index for stream 994 (in stream_add_index() at stream.cpp:1233)
3044:DBG3 - 17:26:56.
914186324 [
3866648/
3866652]: Finding index for stream id 994 and seq_num 1 (in relay_index_get_by_id_or_create() at index.cpp:112)
3045:DBG2 - 17:26:56.
914205597 [
3866648/
3866652]: Index found or created in HT for stream ID 994 and seqnum 1 (in relay_index_get_by_id_or_create() at index.cpp:144)
3046:DBG2 - 17:26:56.
914227502 [
3866648/
3866652]: Writing index for stream ID 994 and seq num 1 (in relay_index_try_flush() at index.cpp:275)
3047:DBG2 - 17:26:56.
914299536 [
3866648/
3866652]: index put for stream id 994 and seqnum 1 refcount 1 (in relay_index_put() at index.cpp:237)
3587:DBG1 - 17:26:57.
067977800 [
3866648/
3866652]: Set begin data pending flag to stream 994 (in relay_begin_data_pending() at main.cpp:2240)
3644:DBG1 - 17:26:57.
070915787 [
3866648/
3866652]: Data pending for stream id 994: prev_data_seq 1, prev_index_seq 1, and last_seq 1 (in relay_data_pending() at main.cpp:2091)
3913:DBG1 - 17:26:57.
093492259 [
3866648/
3866652]: try_rotate_stream_index: Stream 994 (rotate_at_packet_seq_num = 2, received_packet_seq_num = (value = 1, is_set = 1)) (in try_rotate_stream_index() at stream.cpp:482)
3914:DBG1 - 17:26:57.
093525950 [
3866648/
3866652]: Rotating stream 994 index file (in try_rotate_stream_index() at stream.cpp:511)
3915:DBG1 - 17:26:57.
093561064 [
3866648/
3866652]: try_rotate_stream_data: Stream 994 (rotate_at_index_packet_seq_num = 2, rotate_at_prev_data_net_seq = 1, prev_data_seq = 1) (in try_rotate_stream_data() at stream.cpp:357)
3916:DBG1 - 17:26:57.
093591085 [
3866648/
3866652]: Rotating stream 994 data file with size 8192 (in stream_rotate_data_file() at stream.cpp:138)
3917:DBG1 - 17:26:57.
093626697 [
3866648/
3866652]: stream_rotate_data_file: reset tracefile_size_current for stream 994 was 8192 (in stream_rotate_data_file() at stream.cpp:169)
3918:DBG1 - 17:26:57.
093656578 [
3866648/
3866652]: Rotation completed for stream 994 (in stream_complete_rotation() at stream.cpp:66)
4238:DBG1 - 17:26:57.
635064782 [
3866648/
3866652]: Trying to close stream 994 (in try_stream_close() at stream.cpp:883)
4239:DBG1 - 17:26:57.
635098224 [
3866648/
3866652]: Succeeded in closing stream 994 (in try_stream_close() at stream.cpp:983)
4744:DBG1 - 17:26:57.
741972785 [
3866648/
3866655]: Check index status: index_received_seqcount 2 index_sent_seqcount 1 for stream 994 (in check_index_status() at live.cpp:1454)
4745:DBG1 - 17:26:57.
742030216 [
3866648/
3866655]: Sending viewer index for stream 994 offset 4096 (in viewer_get_next_index() at live.cpp:1801)
4747:DBG1 - 17:26:57.
742088421 [
3866648/
3866655]: Index 2 for stream 994 sent (in viewer_get_next_index() at live.cpp:1842)
4750:DBG1 - 17:26:57.
742197990 [
3866648/
3866655]: Sent 4108 bytes for stream 994 (in viewer_get_packet() at live.cpp:1968)
4755:DBG1 - 17:26:57.
932525633 [
3866648/
3866655]: Releasing stream id 994 (in stream_release() at stream.cpp:778)
4756:DBG1 - 17:26:57.
932555313 [
3866648/
3866655]: Rotation completed for stream 994 (in stream_complete_rotation() at stream.cpp:66)
Cause
=====
This log shows the following sequence:
consumer-data consumer-live-timer relayd-main relayd-live babeltrace
1) lttng_consumer_read_subbuffer
2) get next subbuf
3) write data packet to data socket
(starting here the data packet is
somewhere on the network)
4) put next subbuf
5) post_consume()
6) consumer_stream_sync_metadata_index()
7) wait for metadata
8) consumer_stream_sync_metadata()
9) check_stream()
10) set missed_metadata_flush
11) call send_live_beacon(()
12) sample empty ring buffer
13) read current timestamp
14) send inactivity beacon (empty packet)
15) receives a live beacon (@ 17:26:56.
907762798)
16) call consumer_stream_send_index()
17) send packet index to relayd
18) receives a data packet (@ 17:26:56.
907855597)
(at this point the data
packet is received from the
network)
19) ask for next index
20) informs the live viewer of the live beacon (@ 17:26:56.
913457688)
21) receives an index packet (@ 17:26:56.
914227502)
22) ask for next index
23) sends the packet to the viewer (@ 17:26:57.
742197990)
24) observes time going
backwards between the
previous live beacon
and the data packet.
The issue is caused by consumer_stream_sync_metadata_index which is
called after sending a data packet (therefore after having consumed a
data packet from the ring buffer). It invokes the send_live_beacon
callback before sending the index associated with the data packet that
was just sent.
However, this introduces a discrepancy between the live beacon
inactivity guarantees and the yet-to-be-sent packet index: the data
packet sent at [3] can be anywhere on the network, not even received by
the relay daemon, when the live beacon is sampling a now empty ring
buffer at [12], and thus sends a live inactivity beacon to the relay
daemon. Then, when the index is sent by consumer_stream_send_index
[16], its timestamp is in the past compared to the inactivity beacon
sent by send_live_beacon [11].
The purpose of the field "stream->indexes_in_flight" is to prevent
setting the inactivity timestamp in the relay stream when data is
missing for indexes that were received. This works because the indexes
are sent over the control socket, which is where the inactivity beacons
are also sent. It does not however prevent issues the other way around:
data sent prior to the inactivity beacon may or may not have reached
the relay daemon. It is therefore important to make sure that consuming
ring buffer data and sending that data's index vs sampling for an empty
ring buffer and sending an inactivity beacon are correctly ordered.
Solution
========
Send inactivity beacon after packet index.
Also document the purpose of sending an inactivity beacon in this
scenario.
Note
====
This issue is present since lttng-tools 2.7.0 (backported to 2.6.1),
where lttng_ustconsumer_read_subbuffer() invokes
consumer_flush_ust_index() prior to call consumer_stream_write_index().
It was introduced by commit
288bdb302a1 ("Fix: sessiond vs consumerd
push/get metadata deadlock").
Known drawbacks
===============
None.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ied43cc8229413b25e69b40ac218adad420f18797
Mathieu Desnoyers [Fri, 19 Nov 2021 20:11:37 +0000 (15:11 -0500)]
Fix: relayd: ressource leaks on viewer_stream_create error
Observed issue
==============
When facing failure to open viewer stream chunks in the context of "Fix:
relayd: failure to open chunk files concurrently with session clear",
we observe that the relay daemon triggers an assertion due to a
non-empty session hash table on cleanup.
Cause
=====
viewer_stream_create() does a stream_get(), but without any matching
stream_put() on error. This in turn holds a reference on the ctf_trace,
which holds a reference on the session.
By inspecting the code, we notice that the following ressources can be
leaked on error:
- vstream->stream_file.handle,
- vstream->index_file,
- vstream->stream.
In non-error scenarios, viewer_stream_release() is responsible for
releasing references on the composite objects.
The vstream->stream_file.trace_chunk is not an issue because it is put
in the destroy handler (as well as within the release, before having its
vstream->stream_file.trace_chunk pointer set to NULL).
Solution
========
Properly put references on all objects which are contained by the viewer
stream on error by introducing
viewer_stream_release_composite_objects(), which is used both in the
error path of viewer_stream_create() and in viewer_stream_release().
Note
====
Why not move those "put" operations in viewer_stream_destroy ?
This is done in the release to ensure we put references on composite
objects immediately when our own reference reaches 0, rather than
waiting for a grace period through call_rcu, which could then cause
chained call_rcu callbacks and require multiple invocation of
rcu_barrier on relayd exit to guarantee that all callbacks have been
executed and all ressources properly freed.
Known drawbacks
===============
None.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I864b58eda94ebda5e6faea45c922d4e814a15daa
Mathieu Desnoyers [Fri, 19 Nov 2021 16:12:25 +0000 (11:12 -0500)]
Fix: relayd: live: erroneous message timestamp observed from live viewer
Observed issue
==============
Another situation where erroneous message timestamp is observed by the
live viewer. Happens rarely (only two occurrences while running
ust_clear in stress-tests overnight on a 16-core machine).
Triggered with the following test:
# Test ust streaming live clear with viewer with new metadata after clear
# Parameters: tracing_active=0, clear_twice=1, buffer_type=pid
Babeltrace 2 error:
11-19 06:21:02.571 488497 488497 E PLUGIN/SRC.CTF.LTTNG-LIVE handle_late_message@lttng-live.c:1206 [lttng-live] Invalid live stream state: have a late message that is not a packet discarded or event discarded message: late-msg-type=PACKET_BEGINNING
11-19 06:21:02.578 488497 488497 E PLUGIN/SRC.CTF.LTTNG-LIVE next_stream_iterator_for_trace@lttng-live.c:1360 [lttng-live] Late message could not be handled correctly: lttng-live-msg-iter-addr=0x55b4cdee1590, stream-name="stream-1024", curr-msg-ts=
1637302861380968303, last-msg-ts=
1637302861472798701
11-19 06:21:02.578 488497 488497 E PLUGIN/SRC.CTF.LTTNG-LIVE lttng_live_msg_iter_next@lttng-live.c:1802 [lttng-live] Error preparing the next batch of messages: live-iter-status=LTTNG_LIVE_ITERATOR_STATUS_ERROR
11-19 06:21:02.579 488497 488497 W LIB/MSG-ITER bt_message_iterator_next@iterator.c:866 Component input port message iterator's "next" method failed: iter-addr=0x55b4cdecfe30, iter-upstream-comp-name="lttng-live", iter-upstream-comp-log-level=WARNING, iter-upstream-comp-class-type=SOURCE, iter-upstream-comp-class-name="lttng-live", iter-upstream-comp-class-partial-descr="Connect to an LTTng relay daemon", iter-upstream-port-type=OUTPUT, iter-upstream-port-name="out", status=ERROR
Cause
=====
viewer_get_next_index() does not protect its use of the session
ongoing_rotation state by any synchronization mechanism. It only takes
the stream lock, which is not used to protect changes to the ongoing
rotation state with respect to the chunk rename operation performed by
chunk creation at the beginning of the clear command.
Solution
========
Protect the use of the session ongoing rotation state and file open
operations by the session lock in viewer_get_next_index().
Known drawbacks
===============
I don't expect this to cause any real scalability concern considering
the fact that the relay daemon has only two threads, one to handle
session daemon commands, and the other to handle viewer commands.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I242942ac6bc7a9199a17cd9800fc461a397b8955
Mathieu Desnoyers [Fri, 19 Nov 2021 16:08:15 +0000 (11:08 -0500)]
relayd: clarify viewer_get_next_index no rotation condition
The condition identifying cases where a viewer_get_next_index must not
perform a viewer stream rotation is relatively tricky to comprehend.
Split it in two intermediate variables, and use those variables to
print debugging statements when conditions for not performing a
rotation match.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ieca2fbf879c8ed45c0b3aa6035ac32679b12dcdc
Mathieu Desnoyers [Thu, 18 Nov 2021 20:22:39 +0000 (15:22 -0500)]
Fix: relayd: failure to open chunk files concurrently with session clear
Observed issue
==============
When stress-testing ust clear with an active live viewer, we observe a
situation where the live viewer thread fails to open chunk files in
make_viewer_streams() when executed after the creation of the new trace
chunk at the beginning of the clear command:
DBG3 - 16:19:50.
923577790 [40834/40838]: Processing "RELAYD_CREATE_TRACE_CHUNK" command for socket 19 (in relay_process_control_command() at main.cpp:3262)
DBG1 - 16:19:50.
923577730 [40834/40841]: Relay viewer stream 225 not found (in viewer_stream_get_by_id() at viewer-stream.cpp:265)
DBG1 - 16:19:50.
923600762 [40834/40838]: lttng_trace_chunk_rename_path from to .tmp_old_chunk (in lttng_trace_chunk_rename_path_no_lock() at trace-chunk.cpp:759)
DBG1 - 16:19:50.
923627202 [40834/40841]: Opening trace chunk file "ust/uid/0/64-bit/my_chan-0_26" (in _lttng_trace_chunk_open_fs_handle_locked() at trace-chunk.cpp:1359)
DBG1 - 16:19:50.
923664685 [40834/40841]: Adding new file "ust/uid/0/64-bit/my_chan-0_26" to trace chunk "(unnamed)" (in lttng_trace_chunk_add_file() at trace-chunk.cpp:1309)
DBG1 - 16:19:50.
923706441 [40834/40841]: Relay viewer stream 226 not found (in viewer_stream_get_by_id() at viewer-stream.cpp:265)
DBG1 - 16:19:50.
923727770 [40834/40841]: Opening trace chunk file "ust/uid/0/64-bit/my_chan-0_27" (in _lttng_trace_chunk_open_fs_handle_locked() at trace-chunk.cpp:1359)
DBG1 - 16:19:50.
923744686 [40834/40841]: Adding new file "ust/uid/0/64-bit/my_chan-0_27" to trace chunk "(unnamed)" (in lttng_trace_chunk_add_file() at trace-chunk.cpp:1309)
DBG1 - 16:19:50.
923773427 [40834/40841]: Relay viewer stream 227 not found (in viewer_stream_get_by_id() at viewer-stream.cpp:265)
DBG1 - 16:19:50.
923803791 [40834/40841]: Opening trace chunk file "ust/uid/0/64-bit/my_chan-0_28" (in _lttng_trace_chunk_open_fs_handle_locked() at trace-chunk.cpp:1359)
DBG1 - 16:19:50.
923831589 [40834/40841]: Adding new file "ust/uid/0/64-bit/my_chan-0_28" to trace chunk "(unnamed)" (in lttng_trace_chunk_add_file() at trace-chunk.cpp:1309)
DBG1 - 16:19:50.
923865981 [40834/40841]: Relay viewer stream 228 not found (in viewer_stream_get_by_id() at viewer-stream.cpp:265)
DBG1 - 16:19:50.
923889329 [40834/40841]: Opening trace chunk file "ust/uid/0/64-bit/index/my_chan-0_29.idx" (in _lttng_trace_chunk_open_fs_handle_locked() at trace-chunk.cpp:1359)
DBG1 - 16:19:50.
923905142 [40834/40838]: Creating trace chunk: chunk_id = 1, creation time =
20211118-161950 (in lttng_trace_chunk_create() at trace-chunk.cpp:440)
DBG1 - 16:19:50.
923907984 [40834/40841]: Adding new file "ust/uid/0/64-bit/index/my_chan-0_29.idx" to trace chunk "(unnamed)" (in lttng_trace_chunk_add_file() at trace-chunk.cpp:1309)
DBG1 - 16:19:50.
923937804 [40834/40838]: Chunk name set to "20211118T161950+0000-1" (in lttng_trace_chunk_create() at trace-chunk.cpp:471)
PERROR - 16:19:50.
923984288 [40834/40841]: Failed to open fs handle to ust/uid/0/64-bit/index/my_chan-0_29.idx, open() returned: No such file or directory (in fd_tracker_open_fs_handle() at fd-tracker.cpp:548)
DBG1 - 16:19:50.
924050763 [40834/40841]: Opening trace chunk file "ust/uid/0/64-bit/my_chan-0_29" (in _lttng_trace_chunk_open_fs_handle_locked() at trace-chunk.cpp:1359)
DBG1 - 16:19:50.
924074480 [40834/40841]: Adding new file "ust/uid/0/64-bit/my_chan-0_29" to trace chunk "(unnamed)" (in lttng_trace_chunk_add_file() at trace-chunk.cpp:1309)
PERROR - 16:19:50.
924094720 [40834/40841]: Failed to open fs handle to ust/uid/0/64-bit/my_chan-0_29, open() returned: No such file or directory (in fd_tracker_open_fs_handle() at fd-tracker.cpp:548)
DBG1 - 16:19:50.
924193679 [40834/40841]: Viewer connection closed with 23 (in thread_worker() at live.cpp:2542)
DBG1 - 16:19:50.
924227482 [40834/40838]: Attempting to publish trace chunk: sessiond {
34038782-6f74-4b2d-801e-
752cf3d8885e}, session_id = 7, chunk_id = 1 (in sessiond_trace_chunk_registry_publish_chunk() at sessiond-trace-chunks.cpp:385)
DBG1 - 16:19:50.
924312916 [40834/40838]: Reset communication state of relay connection (fd = 19) (in connection_reset_protocol_state() at connection.cpp:82)
DBG3 - 16:19:50.
924350200 [40834/40838]: Relayd worker thread polling... (in relay_thread_worker() at main.cpp:3833)
DBG3 - 16:19:50.
924365222 [40834/40841]: Relayd live viewer worker thread polling... (in thread_worker() at live.cpp:2456)
DBG1 - 16:19:50.
926718319 [40834/40838]: Done receiving control command header: fd = 19, cmd = 18, cmd_version = 0, payload size = 532 bytes (in relay_process_control_receive_header() at main.cpp:3422)
DBG3 - 16:19:50.
926755574 [40834/40838]: Relayd worker thread polling... (in relay_thread_worker() at main.cpp:3833)
DBG1 - 16:19:50.
926787638 [40834/40838]: Done receiving control command payload: fd = 19, payload size = 532 bytes (in relay_process_control_receive_payload() at main.cpp:3339)
DBG3 - 16:19:50.
926811247 [40834/40838]: Processing "RELAYD_ROTATE_STREAMS" command for socket 19 (in relay_process_control_command() at main.cpp:3258)
Cause
=====
This is caused by relay_create_trace_chunk() using
lttng_trace_chunk_rename_path() to move away each trace subdirectory
into the subdirectory .tmp_old_chunk, and making this the new top-level
chunk directory (temporarily). This is a temporary state which will be
resorbed on relay_close_trace_chunk(), moving back the top-level chunk
directory to its original place.
Attempts to open chunk files from the prior chunk may result in failures,
because the chunk lock protecting the chunk rename operation only
protects the chunk owned by the relay thread, not its copy(ies) owned by
the live viewer thread.
This intermediate state should _not_ be observed by the live viewer
thread. The session ongoing rotation state should prevent the live
viewer threads from observing this.
Solution
========
Set the ongoing rotation state in relay_create_trace_chunk() earlier:
before invoking lttng_trace_chunk_rename_path(). Also ensure that the
session ongoing rotation state is protected by the session lock.
On the live thread side, introduce use of the session ongoing rotation
state in viewer_get_new_streams() and viewer_attach_session() to
effectively skip creation of the viewer streams if a session has a
rotation ongoing.
Viewers are expected to deal with the LTTNG_VIEWER_NEW_STREAMS_NO_NEW
reply (or handle the fact that no streams are currently available) and
try again later.
Both Babeltrace 2.0 and Babeltrace 1.5 appear to handle those replies
correctly.
Known drawbacks
===============
None.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3ad8d59dff2994bfb62efa02a620f3c0ffbb5e3b
Simon Marchi [Thu, 16 Dec 2021 04:13:45 +0000 (23:13 -0500)]
common: compile argpar-utils as C++
argpar-utils was in review while everything was converted to be compiled
as C++, so it missed the boat. Do it now.
Change-Id: Ica005b3b27cc0bd9ef6e886d7078649096c7c7a2
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Mathieu Desnoyers [Wed, 17 Nov 2021 16:55:36 +0000 (11:55 -0500)]
Fix: relayd: live: metadata stream reference count < 0 assert
Observed issue
==============
While running tests/regression/tools/clear/test_ust test in a loop we
eventually witness the following error:
The symptom on the Babeltrace side is a Connection reset by peer. This
is caused by a relayd abort after an assertion failure due to a
reference count being lower than 0.
Test case:
# Test ust streaming live clear with viewer
# Parameters: tracing_active=0, clear_twice=0, buffer_type=pid
Tools commit: https://review.lttng.org/c/lttng-tools/+/6754/1
Relay daemon assertion failure stack trace:
(gdb) bt
#0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1 0x00007ffa2e850859 in __GI_abort () at abort.c:79
#2 0x00007ffa2e850729 in __assert_fail_base (fmt=0x7ffa2e9e6588 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x56221bdb96f4 "res >= 0",
file=0x56221bdb97a0 "/root/virtenv/usr/include/urcu/ref.h", line=66, function=<optimized out>) at assert.c:92
#3 0x00007ffa2e861f36 in __GI___assert_fail (assertion=assertion@entry=0x56221bdb96f4 "res >= 0", file=file@entry=0x56221bdb97a0 "/root/virtenv/usr/include/urcu/ref.h", line=line@entry=66,
function=function@entry=0x56221bdbd638 <__PRETTY_FUNCTION__.7554> "urcu_ref_put") at assert.c:101
#4 0x000056221bd6a1cc in urcu_ref_put (release=<optimized out>, ref=0x7ffa24008cb0) at /root/virtenv/usr/include/urcu/ref.h:66
#5 viewer_stream_put (vstream=vstream@entry=0x7ffa24008cb0) at viewer-stream.c:279
#6 0x000056221bd5e4c5 in viewer_get_metadata (conn=conn@entry=0x7ffa0c000fc0) at live.c:2211
#7 0x000056221bd63778 in process_control (conn=0x7ffa0c000fc0, recv_hdr=0x7ffa297c5af0) at live.c:2376
#8 thread_worker (data=<optimized out>) at live.c:2541
#9 0x00007ffa2ea28609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#10 0x00007ffa2e94d293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Babeltrace crash:
11-17 05:13:05.197 47007 47007 D PLUGIN/SRC.CTF.LTTNG-LIVE/VIEWER lttng_live_get_next_index@viewer-connection.c:1494 [live] Requesting next index for stream: cmd=GET_NEXT_INDEX, viewer-stream-id=3352
11-17 05:13:05.215 47007 47007 E PLUGIN/SRC.CTF.LTTNG-LIVE/VIEWER lttng_live_recv@viewer-connection.c:245 [live] Error receiving from Relay: Connection reset by peer.
11-17 05:13:05.215 47007 47007 E PLUGIN/SRC.CTF.LTTNG-LIVE/VIEWER lttng_live_get_next_index@viewer-connection.c:1522 [live] Error receiving get next index reply
11-17 05:13:05.215 47007 47007 D PLUGIN/SRC.CTF.LTTNG-LIVE lttng_live_iterator_next_msg_on_stream@lttng-live.c:1069 [live] Returning from advancing live stream iterator: status=LTTNG_LIVE_ITERATOR_STATUS_ERROR, stream-name="stream-3352", viewer-stream-id=3352
11-17 05:13:05.215 47007 47007 E PLUGIN/SRC.CTF.LTTNG-LIVE lttng_live_msg_iter_next@lttng-live.c:1802 [live] Error preparing the next batch of messages: live-iter-status=LTTNG_LIVE_ITERATOR_STATUS_ERROR
11-17 05:13:05.216 47007 47007 W LIB/MSG-ITER bt_message_iterator_next@iterator.c:866 Component input port message iterator's "next" method failed: iter-addr=0x563b7dd07700, iter-upstream-comp-name="live", iter-upstream-comp-log-level=TRACE, iter-upstream-comp-class-type=SOURCE, iter-upstream-comp-class-name="lttng-live", iter-upstream-comp-class-partial-descr="Connect to an LTTng relay daemon", iter-upstream-port-type=OUT
PUT, iter-upstream-port-name="out", status=ERROR
11-17 05:13:05.216 47007 47007 E PLUGIN/FLT.UTILS.MUXER muxer_upstream_msg_iter_next@muxer.c:446 [mux] Upstream iterator's next method returned an error: status=ERROR
11-17 05:13:05.216 47007 47007 E PLUGIN/FLT.UTILS.MUXER validate_muxer_upstream_msg_iters@muxer.c:989 [mux] Cannot validate muxer's upstream message iterator wrapper: muxer-msg-iter-addr=0x563b7dd04740, muxer-upstream-msg-iter-wrap-addr=0x563b7dd0db30
11-17 05:13:05.216 47007 47007 E PLUGIN/FLT.UTILS.MUXER muxer_msg_iter_next@muxer.c:1417 [mux] Cannot get next message: comp-addr=0x563b7dd1a760, muxer-comp-addr=0x563b7dd1b930, muxer-msg-iter-addr=0x563b7dd04740, msg-iter-addr=0x563b7dd07590, status=ERROR
11-17 05:13:05.216 47007 47007 W LIB/MSG-ITER bt_message_iterator_next@iterator.c:866 Component input port message iterator's "next" method failed: iter-addr=0x563b7dd07590, iter-upstream-comp-name="mux", iter-upstream-comp-log-level=WARNING, iter-upstream-comp-class-type=FILTER, iter-upstream-comp-class-name="muxer", iter-upstream-comp-class-partial-descr="Sort messages from multiple inpu", iter-upstream-port-type=OUTPUT,
iter-upstream-port-name="out", status=ERROR
11-17 05:13:05.216 47007 47007 W LIB/GRAPH consume_graph_sink@graph.c:462 Component's "consume" method failed: status=ERROR, comp-addr=0x563b7dd06d20, comp-name="pretty", comp-log-level=WARNING, comp-class-type=SINK, comp-class-name="pretty", comp-class-partial-descr="Pretty-print messages (`text` fo", comp-class-is-frozen=1, comp-class-so-handle-addr=0x563b7dd051b0, comp-class-so-handle-path="/root/virtenv/usr/lib/babeltr
ace2/plugins/babeltrace-plugin-text.so", comp-input-port-count=1, comp-output-port-count=0
11-17 05:13:05.217 47007 47007 E CLI cmd_run@babeltrace2.c:2537 Graph failed to complete successfully
Cause
=====
Both relay and live threads can put the ownership reference on the
metadata viewer stream concurrently without synchronization, thus
leading to a reference count going lower than 0.
The viewer stream ownership design initially planned for being owned by
the live thread, thus allowing the live thread to put the ownership
reference as soon as the associated relay stream is observed as closed,
and the viewer stream is considered as hung up.
However, in the specific case of the metadata viewer stream, the
responsibility of closing the metadata viewer stream is shared between
the relay and live threads, because the viewers expect to observe a
LTTNG_VIEWER_NO_NEW_METADATA message before the metadata stream
hangs up (see comment in viewer_get_metadata()). Therefore, if
viewer_get_metadata() is done before the metadata stream is closed, the
viewer will receive the LTTNG_VIEWER_NO_NEW_METADATA message, and set
the no_new_metadata_notified state to true. It's then the relay thread's
relay_close_stream() which will invoke the ownership put. However,
the live thread may concurrently try to put the viewer stream ownership
as well from a subsequent viewer_get_metadata(), thus leading to a
reference count < 0.
Solution
========
Fix this by putting the ownership reference from the live viewer thread
rather than the relay thread. This can be done by tracking the state of
no_new_metadata_notified within the live viewer thread.
Known drawbacks
===============
This will postpone reclaim of the metadata viewer stream from the
relay stream close to the following viewer_get_metadata (after a
LTTNG_VIEWER_NO_NEW_METADATA message has been replied), which I don't
think is an issue.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9783d3a8402dddaa364a7a69c0764eaf30c16fde
Mathieu Desnoyers [Thu, 18 Nov 2021 15:37:29 +0000 (10:37 -0500)]
Fix: relayd: compare viewer chunks by ID rather than address
Observed issue
==============
In "Fix: relayd: live: erroneous message timestamp observed from live
viewer", we observe that sometimes viewer streams unexpectedly end up
performing a viewer stream rotation at session destroy.
Cause
=====
This may happen in the following scenario:
1) Relay stream A is rotated to NULL.
2) viewer_get_next_index for viewer stream A:
2.1) observes a NULL rstream->trace_chunk, updates the viewer session
current trace chunk to NULL (viewer_session_set_trace_chunk_copy).
2.2) "Transition the viewer stream into the latest trace chunk
available." does not issue viewer_stream_rotate_to_trace_chunk, because
the condition (rstream->completed_rotation_count ==
vstream->last_seen_rotation_count + 1 && !rstream->trace_chunk)
evaluates to "true", and thus the entire if () evaluates to false.
3) check_index_status detects rstream->closed and
index_received_seqcount == index_sent_seqcount, thus replying HUP to
viewer, effectively releasing ownership of the viewer stream.
4) viewer_get_next_index for viewer stream B (not rotated to NULL yet):
4.1) observes a non-NULL rstream->trace_chunk, updates the viewer
session current trace chunk to *a new copy* of the non-NULL
rstream->trace_chunk (viewer_session_set_trace_chunk_copy).
4.2) the comparison (conn->viewer_session->current_trace_chunk !=
vstream->stream_file.trace_chunk) done by pointer don't match, because
the viewer session current trace chunk is a new copy.
Therefore, due to those stream close scenarios where the viewer session
can go back and forth between NULL and _different copies_ of the relay
chunk, we cannot use a comparison of chunks by address on the viewer
chunks.
Solution
========
Compare the viewer stream chunks by ID rather than address.
Known drawbacks
===============
The comparison is probably slightly slower, but I don't expect this to
be significant.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I05e4f97f26b2659c007726cc29d3edafa17bdb98
Mathieu Desnoyers [Tue, 16 Nov 2021 20:59:01 +0000 (15:59 -0500)]
Fix: relayd: live: erroneous message timestamp observed from live viewer
Observed issue
==============
While running tests/regression/tools/clear/test_ust test in a loop we
eventually witness the following error:
# Test ust basic streaming live with viewer
# Parameters: tracing_active=0, clear_twice=0, buffer_type=uid
ok 425 - Create session 6jbcTSKUG7s2RIp5 with uri:net://localhost and opts: --live
ok 426 - Enable channel chan for session 6jbcTSKUG7s2RIp5
ok 427 - Enable ust event tp:tptest for session 6jbcTSKUG7s2RIp5
ok 428 - Start tracing for session 6jbcTSKUG7s2RIp5
# Waiting for live trace at url: net://localhost
ok 429 - Waiting for live trace at url: net://localhost
# Waiting for live viewers on url: net://localhost
ok 430 - Waiting for live viewers on url: net://localhost
# Wait until viewer sees all 10 expected events
ok 431 - Live viewer read 10 events, expect 10
ok 432 - Destroy session 6jbcTSKUG7s2RIp5
# Waiting for application to exit
ok 433 - Wait for application to exit
# Wait for viewer to exit
10-28 22:07:37.935 764967 764967 E PLUGIN/SRC.CTF.LTTNG-LIVE next_stream_iterator_for_trace@lttng-live.c:1222 [lttng-live] Message's timestamp is less than lttng-live's message iterator's last returned timestamp: lttng-live-msg-iter-addr=0x55fe45d4977
0, ts=
1635458857116911882, last-msg-ts=
1635458857123908033
10-28 22:07:37.937 764967 764967 E PLUGIN/SRC.CTF.LTTNG-LIVE lttng_live_msg_iter_next@lttng-live.c:1662 [lttng-live] Error preparing the next batch of messages: live-iter-status=LTTNG_LIVE_ITERATOR_STATUS_ERROR
10-28 22:07:37.937 764967 764967 W LIB/MSG-ITER bt_message_iterator_next@iterator.c:861 Component input port message iterator's "next" method failed: iter-addr=0x55fe45d38c50, iter-upstream-comp-name="lttng-live", iter-upstream-comp-log-level=WARNING,
iter-upstream-comp-class-type=SOURCE, iter-upstream-comp-class-name="lttng-live", iter-upstream-comp-class-partial-descr="Connect to an LTTng relay daemon", iter-upstream-port-type=OUTPUT, iter-upstream-port-name="out", status=ERROR
10-28 22:07:37.937 764967 764967 E PLUGIN/FLT.UTILS.MUXER muxer_upstream_msg_iter_next@muxer.c:452 [muxer] Upstream iterator's next method returned an error: status=ERROR
10-28 22:07:37.938 764967 764967 E PLUGIN/FLT.UTILS.MUXER validate_muxer_upstream_msg_iters@muxer.c:986 [muxer] Cannot validate muxer's upstream message iterator wrapper: muxer-msg-iter-addr=0x55fe45d33640, muxer-upstream-msg-iter-wrap-addr=0x55fe45d3
af20
10-28 22:07:37.938 764967 764967 E PLUGIN/FLT.UTILS.MUXER muxer_msg_iter_next@muxer.c:1411 [muxer] Cannot get next message: comp-addr=0x55fe45d49cb0, muxer-comp-addr=0x55fe45d49d30, muxer-msg-iter-addr=0x55fe45d33640, msg-iter-addr=0x55fe45d38ae0, sta
tus=ERROR
10-28 22:07:37.938 764967 764967 W LIB/MSG-ITER bt_message_iterator_next@iterator.c:861 Component input port message iterator's "next" method failed: iter-addr=0x55fe45d38ae0, iter-upstream-comp-name="muxer", iter-upstream-comp-log-level=WARNING, iter
-upstream-comp-class-type=FILTER, iter-upstream-comp-class-name="muxer", iter-upstream-comp-class-partial-descr="Sort messages from multiple inpu", iter-upstream-port-type=OUTPUT, iter-upstream-port-name="out", status=ERROR
10-28 22:07:37.938 764967 764967 W LIB/GRAPH consume_graph_sink@graph.c:469 Component's "consume" method failed: status=ERROR, comp-addr=0x55fe45d49550, comp-name="pretty", comp-log-level=WARNING, comp-class-type=SINK, comp-class-name="pretty", comp-c
lass-partial-descr="Pretty-print messages (`text` fo", comp-class-is-frozen=0, comp-class-so-handle-addr=0x55fe45d38460, comp-class-so-handle-path="/root/virtenv/usr/lib/babeltrace2/plugins/babeltrace-plugin-text.la", comp-input-port-count=1, comp-out
put-port-count=0
10-28 22:07:37.938 764967 764967 E CLI cmd_run@babeltrace2.c:2547 Graph failed to complete successfully
Cause
=====
When doing the rotation associated with a clear,
viewer_stream_sync_tracefile_array_tail aims at pushing forward the
index_sent_seqcount for sessions in tracefile rotation mode to the
oldest available seqcount (tail) for this stream. It does not take into
consideration that the current index_sent_seqcount may already be passed
that oldest available seqcount position, thus eventually re-emitting
trace data.
For sessions *not* in tracefile rotation mode (this is known because
`tracefile_array_get_seq_tail()` returns -1ULL), this function
erroneously resets the index_sent_seqcount to 0, thus also causing trace
data to be re-emitted.
Solution
========
Solve this by using the maximum between the current index_sent_seqcount
and the tracefile array tail position as new position in
viewer_stream_sync_tracefile_array_tail.
Notes
=====
This symptom is also observed without using the clear command, simply on
destroy with a live viewer attached. This is caused by another issue
(not addressed by this patch) which causes
viewer_stream_rotate_to_trace_chunk to be sometimes invoked when streams
are closed on destroy.
Known drawbacks
===============
None.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ifb877d6e2bd94831ddf93077eac3cc968945d6f7
Mathieu Desnoyers [Wed, 24 Nov 2021 20:56:16 +0000 (15:56 -0500)]
Validate channel context mismatch across UST applications
Observed issue
==============
Applications traced with LTTng-UST are expected to all provide the exact
same layout for their channel's context fields, else it leads to
corrupted traces. This is only enforced within LTTng-UST. There is
nothing in the session daemon that prevents this scenario, and it is
only observable when reading the corrupted trace.
This makes the entire trace unreadable from the point where it is
corrupted.
Cause
=====
Even though LTTng-UST sends the entire description of its context fields
along with the channel registration notification, there is no validation
of the context fields' content against the context fields present in the
ust registry.
Solution
========
Validate each registered UST channel context fields against the fields
present in the registry. Reject the application if there is a mismatch.
Known drawbacks
===============
None.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I8b49032bf4f766e549dfccfafdce8cddcbb2873f
Jérémie Galarneau [Tue, 14 Dec 2021 19:52:24 +0000 (14:52 -0500)]
Fix: relayd comm: improperly packed rotate streams command header
Observed issue
==============
The implicit rotation of a session performed during its destruction
fails on LTTng 2.12 (and upwards) with the following errors:
Error: Relayd rotate streams replied error 152
Error: Relayd rotate stream failed. Cleaning up relayd 2
Error: Rotate channel failed
Failed to find relay daemon socket: relayd_id = 2
Error: Failed to perform a quiet rotation as part of the destruction of session "my_session": Rotation failure on consumer
Cause
=====
Error 152 matches the LTTNG_ERR_INVALID_PROTOCOL error, which implies
that the consumer daemon sent an unexpected command to the relay daemon.
It was determined that the RELAYD_ROTATE_STREAMS command header is not
properly packed since the LTTNG_PACKED annotation was omitted from its
`new_chunk_id` optional field. The documentation of LTTNG_OPTIONAL_COMM
duly indicates that this is required.
Without the use of LTTNG_PACKED, various lengths of padding (3 or 7
bytes) are inserted between new_chunk_id's `is_set` and `value` field to
align `value`, which results in an incorrect interpretation of the
command's arguments.
The relay daemon catches the protocol error when it is built in a
configuration that inserts 7 bytes of padding, while the consumer only
inserts three.
Solution
========
The solution proposed here is not perfect, see "Known drawbacks".
First, if we were to annotate the field, patched consumer daemons would
send unintelligible command headers to unpatched relay daemons. Leaving
it as is is the least of all evils, see "Known drawbacks" for more
details.
From the relay daemon end, we can easily anticipate the padding problem
by reading the `stream_count` field and use it to determine the expected
size of the payload.
The difference between the actual size of the payload and the expected
size allows us to determine the padding size and use the appropriate
declaration of the structure to interpret the command's arguments.
Known drawbacks
===============
While this fix causes the relay daemon to handle all improperly packed
command headers received from an unpatched consumer daemon, the reverse
is not completely true.
The following tables show which cases are known to work and which are
known to be broken when patched and unpatched versions of the relay
and consumer daemons are mixed, with the various alignment constraints.
Note that here:
- 4 byte alignement implies "daemon running on an architecture on
which uint64_t is aligned on an 4-byte boundary" (e.g. x86),
- 8 byte alignement implies "daemon running on an architecture on
which uint64_t is aligned on an 8-byte boundary" (e.g. x86-64).
Scenario 1 - Unpatched relay daemon and unpatched consumer daemon
-----------------------------------------------------------------------------------
| Architecture alignment | 4 byte alignement consumerd | 8 byte alignment consumerd |
|------------------------|-----------------------------|----------------------------|
| 4 byte alignment relay | Works | Fails |
| 8 byte alignment relay | Fails | Works |
-----------------------------------------------------------------------------------
Scenario 2 - Patched relay daemon and unpatched consumer daemon
-----------------------------------------------------------------------------------
| Architecture alignment | 4 byte alignement consumerd | 8 byte alignment consumerd |
|------------------------|-----------------------------|----------------------------|
| 4 byte alignment relay | Works | Works |
| 8 byte alignment relay | Works | Works |
-----------------------------------------------------------------------------------
Scenario 3 - Unpatched relay daemon and patched consumer daemon
-----------------------------------------------------------------------------------
| Architecture alignment | 4 byte alignement consumerd | 8 byte alignment consumerd |
|------------------------|-----------------------------|----------------------------|
| 4 byte alignment relay | Works | Fails |
| 8 byte alignment relay | Fails | Works |
-----------------------------------------------------------------------------------
Scenario 4 - Patched relay daemon and patched consumer daemon
-----------------------------------------------------------------------------------
| Architecture alignment | 4 byte alignement consumerd | 8 byte alignment consumerd |
|------------------------|-----------------------------|----------------------------|
| 4 byte alignment relay | Works | Works |
| 8 byte alignment relay | Works | Works |
-----------------------------------------------------------------------------------
Note that Scenarios 1 and 3 are the same since this fix doesn't
change the behaviour of the consumer daemon.
Also note that packing the `new_chunk_id` field would break the two
working cases of scenario 3 which are, in all likelyhood, the more
common cases.
A new command using a properly packed version of the command's header
could be implemented in future versions, but this presents no benefit as
part of this fix.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3b822a9766ea5be51996a771a0d4a90efe29ce0b
Jonathan Rajotte [Thu, 18 Nov 2021 15:47:16 +0000 (10:47 -0500)]
Test: snapshot after regenerate metadata
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I48ae0e9d3d4e67172c4a686d42ceadf6bcb81ead
Jonathan Rajotte [Wed, 17 Nov 2021 21:18:59 +0000 (16:18 -0500)]
Fix: ust-consumer: segfault on snapshot after regenerate metadata
Observed issue
==============
lttng-consumerd segfaults for the following scenario:
$ lttng create test --snapshot
$ lttng enable-event -u -an
$ lttng start
# Run an app just to have some events
$ lttng regenerate metadata
$ lttng snapshot record
The following backtrace is obtained:
(gdb) bt
#0 __GI___pthread_mutex_lock (mutex=0x130) at ../nptl/pthread_mutex_lock.c:67
#1 0x000055b383cfaed3 in lttng_ustconsumer_recv_metadata (sock=29, key=4, offset=0, len=12391, version=1, channel=0x7fe90000a760, timer=0, wait=1) at ust-consumer.c:1347
#2 0x000055b383d00197 in lttng_ustconsumer_request_metadata (ctx=0x55b3855a1e50, channel=0x7fe90000a760, timer=0, wait=1) at ust-consumer.c:3336
#3 0x000055b383cf9e76 in snapshot_metadata (metadata_channel=0x7fe90000a760, key=4, path=0x7fe911a09944 "uid/1000/64-bit", relayd_id=
18446744073709551615, ctx=0x55b3855a1e50) at ust-consum
#4 0x000055b383cfbe73 in lttng_ustconsumer_recv_cmd (ctx=0x55b3855a1e50, sock=28, consumer_sockpoll=0x7fe911a0dbb0) at ust-consumer.c:1853
#5 0x000055b383ccf9b7 in lttng_consumer_recv_cmd (ctx=0x55b3855a1e50, sock=28, consumer_sockpoll=0x7fe911a0dbb0) at consumer.c:2097
#6 0x000055b383cd3bfd in consumer_thread_sessiond_poll (data=0x55b3855a1e50) at consumer.c:3284
#7 0x00007fe914c22609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#8 0x00007fe914b47293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
(gdb) up
#1 0x000055b383cfaed3 in lttng_ustconsumer_recv_metadata (sock=29, key=4, offset=0, len=12391, version=1, channel=0x7fe90000a760, timer=0, wait=1) at ust-consumer.c:1347
1347 pthread_mutex_lock(&channel->metadata_stream->lock);
(gdb) print channel->metadata_stream
$1 = (struct lttng_consumer_stream *) 0x0
Note that the following scenario also leads to a similar backtrace:
$ lttng create test --snapshot
$ lttng enable-event -u -an
$ lttng start
# Run an app just to have some events with a short duration
$ lttng regenerate metadata
# Run a second app just to have some events and a metadata flush while
# the metadata cache status is set as `invalidated`.
^ lttng-consumerd segfault on app termination.
The backtrace:
(gdb) bt
#0 __GI___pthread_mutex_lock (mutex=0x130) at ../nptl/pthread_mutex_lock.c:67
#1 0x00005612a5a13ed3 in lttng_ustconsumer_recv_metadata (sock=28, key=2, offset=0, len=12391, version=1, channel=0x7f3978005400, timer=0, wait=1) at ust-consumer.c:1347
#2 0x00005612a5a14d0a in lttng_ustconsumer_recv_cmd (ctx=0x5612a6feee50, sock=28, consumer_sockpoll=0x7f3989494bb0) at ust-consumer.c:1818
#3 0x00005612a59e89b7 in lttng_consumer_recv_cmd (ctx=0x5612a6feee50, sock=28, consumer_sockpoll=0x7f3989494bb0) at consumer.c:2097
#4 0x00005612a59ecbfd in consumer_thread_sessiond_poll (data=0x5612a6feee50) at consumer.c:3284
#5 0x00007f398c6a9609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#6 0x00007f398c5ce293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
(gdb) up
#1 0x00005612a5a13ed3 in lttng_ustconsumer_recv_metadata (sock=28, key=2, offset=0, len=12391, version=1, channel=0x7f3978005400, timer=0, wait=1) at ust-consumer.c:1347
1347 pthread_mutex_lock(&channel->metadata_stream->lock);
(gdb) print channel->metadata_stream
$1 = (struct lttng_consumer_stream *) 0x0
(gdb)
Cause
=====
For session configured in snapshot mode the metadata channel
metadata_stream field is NULL except for a "short" window during the
actual snapshot record action (snapshot_metadata).
The `regenerate metadata` effectively flag the metadata cache as invalid
leading to handling the cache invalidation state
(`CONSUMER_METADATA_CACHE_WRITE_STATUS_INVALIDATED`) in
`lttng_ustconsumer_recv_metadata`. This was introduced by
b1316da1ffbd276fc8271e7a9438e683ad352781 [1].
At that point the function expects the `channel->metadata_stream` to be
non null. This is simply not true for snapshot session metadata channels.
Note that we cannot simply swap `lttng_ustconsumer_request_metadata` and
`create_ust_streams` in `snapshot_metadata` to ensure that the
`channel->metadata_stream` is non null since
`lttng_ustconsumer_recv_metadata` ends up being called on metadata flush when
an app quit. This sequence of events corresponds to the second scenario
put forward in the `Observed Issue` section.
Solution
========
Null check `channel->metadata_stream` and perform only the operation
when it is non null. This partly mirror what is done in `consumer_metadata_wakeup_pipe`.
I am not sure if the check on `channel->monitor` is required but it
seems irrelevant to the notion of resetting the stream consumed position
when the stream exists.
With this taken care off, we find ourself with another
backtrace:
#0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 [93/122]
#1 0x00007f75cf9b3859 in __GI_abort () at abort.c:79
#2 0x00007f75cf9b3729 in __assert_fail_base (fmt=0x7f75cfb49588 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x55ab004e9c68 "pthread_mutex_trylock(&stream->lock)", file=0x55ab004
#3 0x00007f75cf9c4f36 in __GI___assert_fail (assertion=0x55ab004e9c68 "pthread_mutex_trylock(&stream->lock)", file=0x55ab004e8d7a "ust-consumer.c", line=1285, function=0x55ab004eb8a0 <__PR
#4 0x000055ab004b1b9c in metadata_stream_reset_cache_consumed_position (stream=0x7f75b400a850) at ust-consumer.c:1285
#5 0x000055ab004b4fef in commit_one_metadata_packet (stream=0x7f75b400a850) at ust-consumer.c:2551
#6 0x000055ab004b5f46 in get_next_subbuffer_metadata (stream=0x7f75b400a850, subbuffer=0x7f75cc972630) at ust-consumer.c:2927
#7 0x000055ab0048b6a9 in lttng_consumer_read_subbuffer (stream=0x7f75b400a850, ctx=0x55ab01d4ee50, locked_by_caller=true) at consumer.c:3522
#8 0x000055ab004b0f66 in snapshot_metadata (metadata_channel=0x7f75b4005400, key=2, path=0x7f75cc972944 "uid/1000/64-bit", relayd_id=
18446744073709551615, ctx=0x55ab01d4ee50) at ust-consum
#9 0x000055ab004b2e86 in lttng_ustconsumer_recv_cmd (ctx=0x55ab01d4ee50, sock=28, consumer_sockpoll=0x7f75cc976bb0) at ust-consumer.c:1861
#10 0x000055ab004869b7 in lttng_consumer_recv_cmd (ctx=0x55ab01d4ee50, sock=28, consumer_sockpoll=0x7f75cc976bb0) at consumer.c:2097
#11 0x000055ab0048abfd in consumer_thread_sessiond_poll (data=0x55ab01d4ee50) at consumer.c:3284
#12 0x00007f75cfb8b609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#13 0x00007f75cfab0293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Which is also caused in part to the invalidation of the cache.
`metadata_stream_reset_cache_consumed_position` expect that the stream
at that point be locked. Which is not the case despite what the last argument
to `lttng_consumer_read_subbuffer` indicates. To alleviate that we hold
the lock during the call to `lttng_consumer_read_subbuffer`.
Known drawbacks
=========
None.
References
=========
[1] https://git.lttng.org/?p=lttng-tools.git;a=commit;h=
b1316da1ffbd276fc8271e7a9438e683ad352781
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib09fdc989b1baae26d0f496afeabc3e7cb27228c
Simon Marchi [Wed, 25 Aug 2021 18:39:11 +0000 (14:39 -0400)]
lttng: list valid condition / action names if missing or unknown
I think it would be helpful to the user to list the condition and action
names, when the condition or action name is missing or unrecognized.
This patch implements that, here are some examples of the result:
$ lttng add-trigger --action notify --condition
Error: While parsing argument #4: Missing required argument for option `--condition`
Error: Valid condition names are:
Error: event-rule-matches
$ lttng add-trigger --action notify --condition pouet
Error: While parsing argument #5: Unknown condition name 'pouet'
Error: Valid condition names are:
Error: event-rule-matches
$ lttng add-trigger --condition event-rule-matches --action
Error: While parsing argument #4: Missing required argument for option `--action`
Error: Valid action names are:
Error: notify
$ lttng add-trigger --condition event-rule-matches --action pouet
Error: While parsing argument #5: Unknown action name: pouet
Error: Valid action names are:
Error: notify
To achieve this, add a new optional out argument to parse_next_item, to
allow the caller to get the argpar_error object if a parsing error
happened. Because of this, the callers must now be able to
differentiate parsing error from memory errors: in the latter case, no
argpar_error object is returned. So, add a new
PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY status, and make users of
parse_next_item handle it.
In the add-trigger command implementation, handle the "missing opt arg"
case of OPT_ACTION and OPT_CONDITION specially to print the valid names.
Handle unknown names in parse_action and parse_condition.
Add a test for an unknown action name, it seems to be missing. Change
the error message format slightly to make it match the messages for
unknown condition names.
Change-Id: I4c13cecacb3a2ff4367e391c4aba0d05f1f28f22
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Simon Marchi [Tue, 24 Aug 2021 21:50:32 +0000 (17:50 -0400)]
lttng: mention argument number on unknown action / condition name
When a unrecognized condition or action name is given, the error message
does not contain the part that mentions the argument index, like
argument parsing error messages have:
$ lttng add-trigger --action notify --condition pouet
Error: Unknown condition name 'pouet'
I think it would be useful to have it, it can help when you have really
long command lines (something possible with add-trigger). The result
is:
$ lttng add-trigger --action notify --condition pouet
Error: While parsing argument #4 (`--condition`): Unknown condition name 'pouet'
$ lttng add-trigger --action notify --condition=pouet
Error: While parsing argument #4 (`--condition=pouet`): Unknown condition name 'pouet'
$ lttng add-trigger --condition event-rule-matches --action pouet
Error: While parsing argument #4 (`--action`): Unknown action name: pouet
$ lttng add-trigger --condition event-rule-matches --action=pouet
Error: While parsing argument #4 (`--action=pouet`): Unknown action name: pouet
Change-Id: Ic1a00cffa87ea7b3569b24c7417a00d7a52555f2
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Simon Marchi [Wed, 25 Aug 2021 18:34:25 +0000 (14:34 -0400)]
lttng: fix argument numbers in add-trigger error messages
Argument numbers in add-trigger argument parsing error messages are
wrong. For example:
$ ./src/bin/lttng/lttng add-trigger --condition event-rule-matches --foo
Error: While parsing argument #1 (`--foo`): Unknown option `--foo`
This is due to the fact that multiple separate argpar iterators are
created to parse an add-trigger command line. Iterators are created at
the top-level, to parse the top-level arguments. Iterators are also
created when parsing a condition or an action, to parse the arguments
specific to that condition or action. As a result, iterators are passed
a subset of the full command line, and the argument indices in the error
messages are off.
Fix that by passing around an "argc offset", which represents by how
much what's being parsed is offset from the full command-line. Use that
to adjust the error messages to give indices that make sense to the
user:
$ ./src/bin/lttng/lttng add-trigger --condition event-rule-matches --foo
Error: While parsing argument #4 (`--foo`): Unknown option `--foo`
Change-Id: I1d312593d338641d0ec10abe515b640771a1f160
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Simon Marchi [Tue, 24 Aug 2021 01:42:42 +0000 (21:42 -0400)]
argpar-utils: tweak unknown option error message
Add the "While parsing argument #X" context, that is used when other
errors are encountered. Before:
Error: Unknown option `--hello`
After:
Error: While parsing argument #1 (`--hello`): Unknown option `--hello`
Change-Id: Ifd84a1e8b1fe0456e09ff154cc515eaa2850a7e1
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Simon Marchi [Fri, 20 Aug 2021 18:39:20 +0000 (14:39 -0400)]
argpar: sync with upstream - adjust to iterator API
Sync with commit
143cec42e14e ("Force usage of ARGPAR_ASSERT() condition
when NDEBUG is defined").
The main change in this sync is the API that changed from
parse-all-at-once (the `argpar_parse` function) to something based on an
iterator, where we need to call `argpar_iter_next` to obtain the next
item. This was prototyped here (in lttng-tools), so this patch converts
the code to the API that was actually implemented in upstream argpar.
A difference between what we had and the current argpar API is that
argpar does not provide a formatted error string anymore. It provides
an `argpar_error` object contaning all the raw information needed to
create such string. The new `format_arg_error_v` function formats the
errors using the exact same syntax as argpar did, such that no changes
in the tests are necessary.
The new `parse_next_item` function factors out the code around calling
argpar_iter_next that would otherwise be duplicated at a few places.
These two new functions are placed into a new `argpar-utils` convenience
library. I originally put them in the `libcommon.la` convenience
library, but that caused some parts of the code that don't do any
argument parsing (e.g. liblttng-ctl) to have to be linked against
argpar. As a separate library, we can limit that to just the `lttng`
binary.
Change-Id: I94aa90ffcd93f52b6073c4cd7caca78cfd0f2e05
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Simon Marchi [Mon, 23 Aug 2021 18:32:51 +0000 (14:32 -0400)]
configure: enable -Wformat=2
The -Wformat=2 diagnostic flag on GCC enables the -Wformat-nonliteral
-Wformat-security diagnostics, which are useful to catch some format
string mistakes. -Wformat-security is also enabled by default with
Clang, meaning that there were some warnings only appearing with
Clang.
Try to enabled the -Wformat=2 flag to make things more consistent across
compilers and catch more mistakes.
The only issues are these, in tests/regression/ust/linking:
CC demo_builtin-demo.o
In file included from /usr/include/stdio.h:866,
from /home/simark/src/lttng-tools/tests/regression/ust/linking/demo.c:9:
/usr/include/bits/stdio2.h: In function ‘sprintf’:
/usr/include/bits/stdio2.h:40:35: warning: format not a string literal, argument types not checked [-Wformat-nonliteral]
40 | __va_arg_pack ());
| ^~~~~~~~~~~~~
The reason this appears is that this directory uses -Wsystem-headers,
making the compiler show diagnostics in headers considered "system
headers". Manually silence those warnings by disabling
-Wformat-nonliteral in that specific directory.
Change-Id: I4c7991e76b2f5405f3b3397348adb9134de37d41
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Simon Marchi [Fri, 20 Aug 2021 20:10:37 +0000 (16:10 -0400)]
common: move append_str to string-utils
Move the append_str function from filter-visitor-generate-bytecode.c to
the string-utils lib, so that it can be re-used elsewhere.
Change-Id: Ica09cb750ac7f3f2d6f3fb5fc786b683ceb6f79a
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Philippe Proulx [Tue, 7 Dec 2021 20:47:21 +0000 (15:47 -0500)] 
lttng-create(1): specify that `--shm-path` only applies to UST channels
This is a current limitation, but could change in the future.
Fixes: https://bugs.lttng.org/issues/1158
Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie2b8114f35d7fd095790aae6add4653c5da169bf
Jérémie Galarneau [Fri, 10 Dec 2021 21:13:27 +0000 (16:13 -0500)]
Fix: sessiond: action-executor: misquoted strings in logging
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I5b37472c0b9e49116ec542c57346a78359d732d7
Jonathan Rajotte [Fri, 19 Nov 2021 20:03:37 +0000 (15:03 -0500)]
Refactor: action executor: fetch session based on execution context
There is little reason to fetch the session by name if at that point in
the action execution code path the id of the session is available.
Session that are in destroyed state are ignored. This simplify a bit the
overall execution flow.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4a104e3b509c36b0ceea6e01f9dbd043ceb812b1
Jérémie Galarneau [Fri, 10 Dec 2021 19:10:13 +0000 (14:10 -0500)]
Tests: live kernel: no plan printed when non-root
The live kernel test does not produce a valid TAP output when
skipping due to not running the test as root.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4a10de494260084216ddb1b8f4ee27a546c4d8ed
Jonathan Rajotte [Thu, 9 Dec 2021 20:14:26 +0000 (15:14 -0500)]
Fix: sessiond: assert on lttng_ht_add_unique_str on ltt_sessions_ht_by_name
Observed issue
==============
The lttng-sessiond asserts with the following backtrace on lttng create:
#0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1 0x00007ffff7ab5859 in __GI_abort () at abort.c:79
#2 0x00007ffff7ab5729 in __assert_fail_base (fmt=0x7ffff7c4b588 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x5555556ab0a6 "node_ptr == &node->node", file=0x5555556ab085 "hashtable.c", line=298, function=<optimized out>) at a
#3 0x00007ffff7ac6f36 in __GI___assert_fail (assertion=assertion@entry=0x5555556ab0a6 "node_ptr == &node->node", file=file@entry=0x5555556ab085 "hashtable.c", line=line@entry=298, function=function@entry=0x5555556ab380 <__PRETTY_FUNCTIO
#4 0x000055555560be44 in lttng_ht_add_unique_str (ht=<optimized out>, node=0x7fffe0026c58) at hashtable.c:298
#5 0x000055555558fb6a in add_session_ht (ls=0x7fffe0024970) at session.c:372
#6 session_create (name=<optimized out>, uid=1000, gid=1000, out_session=out_session@entry=0x7fffedfddbd8) at session.c:1308
#7 0x000055555559b219 in cmd_create_session_from_descriptor (creds=<optimized out>, creds=<optimized out>, home_path=<optimized out>, descriptor=<optimized out>) at cmd.c:3040
#8 cmd_create_session (cmd_ctx=cmd_ctx@entry=0x7fffedfe5fa0, sock=<optimized out>, return_descriptor=return_descriptor@entry=0x7fffedfddd68) at cmd.c:3176
#9 0x00005555555cc341 in process_client_msg (sock_error=0x7fffedfddd10, sock=0x7fffedfddd0c, cmd_ctx=0x7fffedfe5fa0) at client.c:2177
#10 thread_manage_clients (data=<optimized out>) at client.c:2742
#11 0x00005555555c5fff in launch_thread (data=0x55555571b780) at thread.c:66
#12 0x00007ffff7c8b609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#13 0x00007ffff7bb2293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
The issue can be reproduced with modifications to the rotation thread
code and the following scenario:
$ lttng create test
$ lttng enable-event -u -a
$ lttng start
run any app just so that we have a complete valid session. (might not be necessary)
$ lttng destroy --no-wait
$ lttng create test
^ Should assert here.
The diff to be applied:
diff --git a/src/bin/lttng-sessiond/rotation-thread.cpp b/src/bin/lttng-sessiond/rotation-thread.cpp
index
ac149c845..
c11f068ed 100644
--- a/src/bin/lttng-sessiond/rotation-thread.cpp
+++ b/src/bin/lttng-sessiond/rotation-thread.cpp
@@ -565,6 +565,8 @@ int handle_job_queue(struct rotation_thread_handle *handle,
{
int ret = 0;
+ sleep(5);
+
for (;;) {
struct ltt_session *session;
struct rotation_thread_job *job;
Note that the initial report for this issue was on a system under load
for which the `lttng destroy` completion check failed and a `lttng
create` was performed. As of today the exact reason why the completion
check failed is not known. Still we can "fix" the race leading to the
lttng-sessiond assertion considering a user might use the `--no-wait`
variant of `lttng destroy` and could easily end up in this
situation.
Cause
=====
Note: all `lttng create` commands have the same session name passed as
argument.
On `lttng destroy` the ltt_session object is flagged as destroyed
(ltt_session::destroyed). The removal of the object from the hash
table (ltt_sessions_ht_by_name) will be performed during the
`session_release` which is driven by the session refcount.
A reference on the `ltt_session` object is held for the
rotation initiated by the `lttng destroy` command. The rotation is
enqueued by the rotation thread.
At this point the system is busy and the rotation thread does not run.
We simulate this with a `sleep(5)` during the `handle_job_queue`.
The `lttng destroy --no-wait` returns. If the `--no-wait` option is not
passed the `lttng destroy` command will work as expected and wait for
completion. We can SIGINT the `lttng destroy` command and perform a
`lttng create` yielding the same backtrace.
On `lttng create`, `session_create` validates that the name does not
conflict with an existing session using `session_find_by_name`. It is
important to note that `session_find_by_name` discriminates also on the
`session->destroyed` flag (introduced by [1]).
The `ltt_sessions_ht_by_name` hash table was introduced by [2] to remove
the need to lock the session list to sample a session id during the
queueing of actions to be executed related to a trigger. The assumption
was made that, during the creation phase, the session would
always be unique in that hash table based on its name. This is simply
not true since multiple sessions with the same name can coexist as long
as only a single one is marked as "not destroyed". This is an important
concept due to the refcounting of the object and the feature relying on
the lifetime of the object (i.e rotation). This is mostly valid when
talking about the global session list.
Solution
========
Move the hash table removal earlier during the release of the session
object.
Move the removal from `del_session_ht`, which is done during the
`session_release` function, to the `lttng_session_destroy` function.
It is safe to do so since currently the only user of that hash table
(the action executor) does not care much about destroyed session at that
point.
This ensures that we maintain the uniqueness property of the key (name)
for that hash table on insertion.
The alternative was to expose an hash table that could contain
duplicates and force the handling of a set on all lookups.
Known drawbacks
=========
None.
References
==========
[1] https://git.lttng.org/?p=lttng-tools.git;a=commit;h=
e32d7f274604b77bcd83c24994e88df3761ed658
[2] https://git.lttng.org/?p=lttng-tools.git;a=commit;h=
e1bbf98908a6399f39a9a8bc95bd8b59cecaa816
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2f1d0d6c04ee7210166e9847a850afbe6eaa7609
Jérémie Galarneau [Wed, 3 Nov 2021 02:31:15 +0000 (22:31 -0400)]
Fix: sessiond: snapshot: leak of trace chunk
Valgrind reports a leak after every snapshot record command:
==827791== 430 (280 direct, 150 indirect) bytes in 1 blocks are definitely lost in loss record 34 of 37
==827791== at 0x48435FF: calloc (vg_replace_malloc.c:1117)
==827791== by 0x223D01: zmalloc (macros.h:45)
==827791== by 0x224B79: lttng_trace_chunk_allocate (trace-chunk.c:387)
==827791== by 0x224E41: lttng_trace_chunk_create (trace-chunk.c:427)
==827791== by 0x150B55: session_create_new_trace_chunk (session.c:656)
==827791== by 0x164A11: snapshot_record (cmd.c:5113)
==827791== by 0x1651EE: cmd_snapshot_record (cmd.c:5302)
==827791== by 0x196E74: process_client_msg (client.c:2166)
==827791== by 0x198AF1: thread_manage_clients (client.c:2742)
==827791== by 0x18E245: launch_thread (thread.c:66)
==827791== by 0x4B9E258: start_thread (in /usr/lib/libpthread-2.33.so)
==827791== by 0x4CB45E2: clone (in /usr/lib/libc-2.33.so)
session_set_trace_chunk() on line 5162 returns a reference to the
current trace chunk which is never released.
This also causes tests/regression/tools/snapshots/test_ust_long to fail
due to a file descriptor exhaustion (presumably from using too many
directory file descriptors) when it is executed by an unprivileged user.
The CI doesn't catch this since the long regression test suite is
executed as root.
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4b6e45df48c3daafa2294c80ccd8a2b4d91401e1
Francis Deslauriers [Thu, 28 Oct 2021 15:01:22 +0000 (11:01 -0400)]
Tests: add missing kernel test cases to make check target
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4ae8b8b1c130dd370322c2629f851d6aa1f557e7
Simon Marchi [Fri, 20 Aug 2021 19:19:42 +0000 (15:19 -0400)]
configure: enable -Wsuggest-attribute=format
Enable this warning, which suggests adding format attributes to some
functions, to help with format string validation. Fix the warnings it
generates by using the new ATTR_FORMAT_PRINTF macro.
There is only one spot we can't fix, that is in modprobe.c. The
compiler suggests we add an attribute to the kmod_set_log_fn
declaration, which we can't do, since it's not our code:
/home/simark/src/lttng-tools/src/bin/lttng-sessiond/modprobe.c: In function ‘setup_kmod_ctx’:
/home/simark/src/lttng-tools/src/bin/lttng-sessiond/modprobe.c:286:31: error: argument 2 of ‘kmod_set_log_fn’ might be a candidate for a format attribute [-Werror=suggest-attribute=format]
286 | kmod_set_log_fn(*ctx, log_kmod, NULL);
| ^~~~~~~~
I don't see any other choice but to explicitly ignore that spot.
Introduce some macros to abstract how to ignore specific diagnostics.
This is useful since not all compilers support the same diagnostic
flags. For example, telling clang to ignore -Wsuggest-attribute=format
would give an error.
Change-Id: I71278d7e2cdc66d4bbc59bd966469d0b427e963d
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Simon Marchi [Fri, 20 Aug 2021 19:22:16 +0000 (15:22 -0400)]
tests: sync tests/utils/tap with Babeltrace repository
There are a few fixes / improvements in the Babeltrace version of the
tap library, bring them here. The Babeltrace commit used is
0022a87819b0 ("Fix: clear_string_field(): set first character to 0") In
particular, I'm looking for the TAP_PRINTF_FORMAT fixes, to be able to
enable -Wsuggest-attribute=format. But I think it's easier to keep them
in sync, so bring in all changes, instead of just the TAP_PRINTF_FORMAT
ones.
The only diff not brought are the semicolons in the pass / fail
definitions, which were removed in the previous patch. Those changes
should be brought to the Babeltrace repository.
Bringing in the TAP_PRINTF_FORMAT changes finds a few format string
mistakes in the tests, fix them.
Change-Id: I0d125b313265e72303be8d704ba40554bca87cd1
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Philippe Proulx [Tue, 13 Jul 2021 14:48:19 +0000 (10:48 -0400)]
lttng_strerror(): accept positive and negative codes
Some functions return positive `lttng_error_code` enumerator values
while other return negative values.
Make lttng_strerror() accept positive and negative codes. This improves
the API UX and will make the documentation less complex.
Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I359cef98ae32991d1a01b7f2cd484ece7bab2df9
Jonathan Rajotte [Tue, 23 Nov 2021 17:15:42 +0000 (12:15 -0500)]
Fix: test: use BABELTRACE_BIN instead of babeltrace
Observed issue
==============
The System tests jobs fails on multi-session test since the move to bt2.
Cause
=====
The tests uses `babeltrace` instead of `BABELTRACE_BIN`.
Solution
========
Use `BABELTRACE_BIN`.
Add a babelrace bail out.
While there fix easy shellcheck warning.
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I441d736e85c447c5765bffd520ec2f267c86048f
Michael Jeanson [Wed, 11 Nov 2020 16:18:55 +0000 (11:18 -0500)]
Cleanup: consumerd: update stale comment
Change-Id: If65648f32e5b78cfd4e16d86f4cf9eac6c1b3f43
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Jonathan Rajotte [Thu, 11 Nov 2021 20:02:54 +0000 (15:02 -0500)]
Fix: action executor: ref count imbalance for session object
Observed issue
==============
The following scenario leads to a hang on `lttng destroy`.
# Start lttng-sessiond under gdb
$ gdb lttng-sessiond
set pagination off
set non-stop
start
break action_executor_snapshot_session_handler
$ lttng add-trigger --name my_trigger --condition=event-rule-matches --type=user:tracepoint --name=sample_component:message --action=snapshot-session my_snapshot
$ lttng create --snapshot my_snapshot
$ lttng enable-event -u -a
$ lttng start
$ start an app producing a single sample_component:message
# gdb should break on thread 6
# inside gdb
thread 6
$ lttng destroy my_snapshot
$ lttng create --snapshot my_snapshot
$ lttng enable-event -u -a
$ lttng start
# inside gdb use `continue`
$ lttng destroy my_snapshot
The destroy command hang:
Destroying session my_snapshot.... ....
Cause
=====
The scenario forces the usage of the following code path:
if (session->id != LTTNG_OPTIONAL_GET(item->context.session_id)) {
624├───────────────> DBG("Session id for session `%s` (id: %" PRIu64
625│ " is not the same that was sampled (id: %" PRIu64
626│ " at the moment the work item was enqueued for %s` action of trigger `%s`",
627│ session_name, session->id,
628│ LTTNG_OPTIONAL_GET(item->context.session_id),
629│ get_action_name(action),
630│ get_trigger_name(work_item->trigger));
631│ ret = 0;
632│ goto error_unlock_list;
633│ }
At that point a reference on the session object was taken on line:
610│ session = session_find_by_name(session_name);
But the reference is never put on `error_unlock_list` resulting in a ref
count problem.
Solution
========
Use `session_put` for the code path.
Note that most of the handler also have the same problem that was
introduced by commit
72365501d3148ca977a09bad8de0ec51b427bdd8 [1]
Known drawbacks
=========
None.
Refs
=========
[1] https://github.com/lttng/lttng-tools/commit/
72365501d3148ca977a09bad8de0ec51b427bdd8
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I23c3c089866df74854bbfe64320310c4b28ee41d
Mathieu Desnoyers [Thu, 2 Dec 2021 22:33:55 +0000 (17:33 -0500)]
Fix: relayd: `!vsession->current_trace_chunk` assertion failed
Observed issue
==============
When performing:
#!/bin/bash
lttng create py_syscalls --live
lttng enable-event -u -a
lttng enable-event -k -a
lttng start
babeltrace2 -i lttng-live net://localhost/host/raton/py_syscalls
The relay daemon hits this assertion:
Thread 8 (Thread 0x7fffeeffd700 (LWP 167040) "lttng-relayd"):
#0 0x00007ffff7b1618b in raise () from /lib/x86_64-linux-gnu/libc.so.6
#1 0x00007ffff7af5859 in abort () from /lib/x86_64-linux-gnu/libc.so.6
#2 0x00007ffff7af5729 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#3 0x00007ffff7b06f36 in __assert_fail () from /lib/x86_64-linux-gnu/libc.so.6
#4 0x00005555555889bb in viewer_session_attach (vsession=0x7fffdc001400, session=session@entry=0x7fffe8001180) at viewer-session.c:80
#5 0x000055555557bcff in viewer_attach_session (conn=0x7fffd0001140) at live.c:1275
#6 process_control (conn=0x7fffd0001140, recv_hdr=0x7fffeeffcaf0) at live.c:2341
#7 thread_worker (data=<optimized out>) at live.c:2515
#8 0x00007ffff7ccd609 in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#9 0x00007ffff7bf2293 in clone () from /lib/x86_64-linux-gnu/libc.so.6
Cause
=====
This assert appears to be entirely wrong.
It checks that the "viewer session" has a NULL current trace chunk when
attaching a session to a viewer session, but in the case where a viewer
session has multiple sessions (e.g. with kernel and ust tracing
combined), we are attaching each session individually to the viewer
session, and we set the current trace chunk of the viewer session when
we attach the first session to it.
So it is expected to be non-NULL when attaching the second session.
Solution
========
Remove the assertion.
Known limitations
=================
None.
Fixes: #1335
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4d8f5d5347b4588144ddf449976cae5a94b81b3a
Jérémie Galarneau [Wed, 8 Dec 2021 21:07:29 +0000 (16:07 -0500)]
Docs: relayd: document the semantics of a viewer session trace chunk
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ia0af16114a5adc54b90f60f26ffffe682eecb1a6
Michael Jeanson [Fri, 15 Oct 2021 16:08:13 +0000 (12:08 -0400)]
relayd: do not link lttng-relayd on liblttng-ctl
Building on Cygwin, we get:
libtool: link: gcc -shared .libs/cyglttng-ctl-0.dll.def .libs/lttng-ctl.o .libs/snapshot.o .libs/lttng-ctl-health.o .libs/save.o .libs/load.o .libs/deprecated-symbols.o .libs/channel.o .libs/rotate.o .libs/event.o .libs/destruction-handle.o .libs/clear.o .libs/tracker.o -Wl,--whole-archive ../../../src/common/sessiond-comm/.libs/libsessiond-comm.a ../../../src/common/.libs/libcommon.a -Wl,--no-whole-archive -L/cygdrive/c/Users/jenkins/workspace/lttng-tools_master_winbuild/arch/cygwin64/babeltrace_version/stable-2.0/build/std/conf/relayd-only/liburcu_version/master/test_type/base/deps/build/lib -lxml2 -L/build/lib -lurcu -lurcu-common -lurcu-cds -lrt -pthread -g -O2 -pthread -o .libs/cyglttng-ctl-0.dll -Wl,--enable-auto-image-base -Xlinker --out-implib -Xlinker .libs/liblttng-ctl.dll.a
/usr/lib/gcc/x86_64-pc-cygwin/11/../../../../x86_64-pc-cygwin/bin/ld: cannot export error_log_time: symbol not defined
This is caused by commit
ca806b0b247f ("liblttng-ctl: use export list to
define exported symbols"). liblttng-ctl is not needed on Cygwin, so
rather than fight it to resolve the issue and have liblttng-ctl build on
Cygwin, skip building liblttng-ctl on Cygwin.
liblttng-ctl is currently built on Cygwin because relayd depends on it.
This should not be the case, as relayd does not use liblttng-ctl. Remove
the dependency on liblttng-ctl from lttng-relayd/Makefile.am. Remove the
dependency on libconfig.la (used for session config save and load) as
well. It's included in libcommon.la, so it's redundant, but relayd
doesn't need it anyway.
Change-Id: If7e1944c4a30b8adcdd6e6d3083a94f27988697e
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
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