20 months agoChange "event rule hit" to "event-rule matches" in user interface strings
Simon Marchi [Tue, 27 Apr 2021 18:51:08 +0000 (14:51 -0400)] 
Change "event rule hit" to "event-rule matches" in user interface strings

The condition name was changed from "event rule hit" to "event rule
matches", but there are some leftover user-visible strings with the old
name. Fix them.

Change-Id: I619c9265d68ca6bf4a3ac11ef38cabc715b01110
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
20 months agoFix: relayd: live: data is missing between viewer attach and retry
Jonathan Rajotte [Thu, 6 May 2021 15:14:52 +0000 (11:14 -0400)] 
Fix: relayd: live: data is missing between viewer attach and retry

Observed issue

Data produced between the time a live viewer attach and a viewer
subsequent "polling" is missing from the point of view of the viewer.

Using the following reproducer:

  # A lttng-sessiond is already running
  lttng-relayd -b -vvv > relayd.log 2>&1
  lttng create live --live
  lttng enable-event -u "hello_world:*"
  lttng start

  # Set the "polling" interval at ~30 seconds
  babeltrace2 --retry-duration=30000000 -i lttng-live net://localhost/host/$HOSTNAME/live &

  # Make sure we are in the retry phase of bt2
  sleep 2

  # Produce events
  # Note here that hello perform a sleep of 1 seconds before generating
  # 10 events to make sure lttng-ust had time to register. A total of
  # 100 events is generated.
  for i in `seq 1 10`; do

  # Here we expect to see 100 events outputted at some point (~18
  # seconds (30 - 2 - 10) from that time).
  # No events are received by babeltrace2.
  sleep 40

  # We retry the same exercise a second time.
  echo "Moving to phase 2"
  for i in `seq 1 10`; do

  # Here data is received correctly.
  sleep 40

  kill $pid

  lttng destroy live
  pkill lttng-relayd


At the moment the viewer attach is done, no streams exist. On the
following viewer_get_new_streams (~30 seconds later), streams now exist
since they were allocated lazily following the first application
registration, but LTTNG_VIEWER_SEEK_LAST is used. This essentially
"discards" any events in the stream that happened between the attach
time and the viewer_get_new_stream execution.

Note that the same problem would happen if a new UID (in per-uid mode)
would happen to begin tracing in between viewer retry.



Known drawbacks

This does not fix the per-pid problem where an app run and die in between
the viewer retries.


Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I92fbe6511fb93e31d20922b4eef5c9a221e07716

20 months agoBuild fix: filter-grammar-test: incorrect inclusion flag
Jérémie Galarneau [Thu, 6 May 2021 22:43:44 +0000 (18:43 -0400)] 
Build fix: filter-grammar-test: incorrect inclusion flag

Including src/common causes LTTng files that clash with system headers
to be included before the system headers and breaks the build on
multiple platforms and architectures.

Signed-off-by: Jérémie Galarneau <>
Change-Id: Iff7b6e7000d907dc076a467d223c91569b783861

20 months agoTests: fix: test_tp_fail: bail out on non-existing relay daemon
Jérémie Galarneau [Thu, 6 May 2021 19:48:02 +0000 (15:48 -0400)] 
Tests: fix: test_tp_fail: bail out on non-existing relay daemon

Fatal thread errors simulated by the tp_fail test cause the relay
daemon to shutdown. This is unexepected by stop_lttng_relayd_notap
which bails out, causing the test to fail.

We bail-out when the daemon is already dead to catch crashes
during the test suite since a0f8e310.

Use the clean-up variant so that we don't fail the tests for this
expected outcome.

Signed-off-by: Jérémie Galarneau <>
Change-Id: I02e7f35451b3c81e7e808e9ff96b6c824fa8f904

20 months agobuild system: support rotation example
Jonathan Rajotte [Wed, 28 Apr 2021 00:13:13 +0000 (20:13 -0400)] 
build system: support rotation example

Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Icf5f88dcc725967b7fda66db6e047cdf18a89f01

20 months agoAdd trigger on event rule matches application example
Jonathan Rajotte [Fri, 14 Feb 2020 23:26:39 +0000 (18:26 -0500)] 
Add trigger on event rule matches application example

Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ice78e15aa1f4380925a272def8bcc7ca331c0aa0

20 months agoUpdate the remaining manual pages for LTTng-tools 2.13
Philippe Proulx [Thu, 29 Apr 2021 21:00:07 +0000 (17:00 -0400)] 
Update the remaining manual pages for LTTng-tools 2.13

This patch updates the remaining manual pages for LTTng-tools 2.13.

This patch:

* Improves the consistency of some command descriptions in

* Adds `common-daemon-cfg.txt` which is a section explaining how to
  configure a daemon (session or relay).

  lttng-sessiond(8) and lttng-relayd(8) include this file.

* Adds `lttng-concepts.7.txt` which is an adapted copy of the
  "Core concepts" section of the online LTTng Documentation.

  This centralizes all the LTTng theory into a single manual page
  instead of having this information split into multiple lttng(1)
  command manual pages.

  Many manual pages now refer to lttng-concepts(7), making it possible
  to cut a lot of text in those.

* Updates existing manual pages to:

  * Have a style and voice which is more consistent with the LTTng
    Documentation (website) for 2.13.

  * Fix various terminology ambiguities.

  * Use more textual variables and lists to explain more complex logic
    and processes.

  * Always use the same pattern to specify the behaviour of an lttng(1)
    command depending on the `SESSION` argument or the `--session`

  * For the commands which can perform more than one task, list their
    available tasks at the beginning of the "DESCRIPTION" section.

  * For some lttng(1) commands which can operate on all tracing sessions
    (for example, lttng-clear(1) and lttng-destroy(1)), always indicate
    that they target all your Unix user's tracing sessions or, if your
    Unix user is `root`, the tracing sessions of all the Unix users
    within the root session daemon.

  * Clean the "SEE ALSO" sections.

  * Always have "LTTng" in the "NAME" section of a manual page.

  More specifically:

      * Clarify the tracing session modes.

      * Clarify how the command adds (or not) a snapshot output for a
        snapshot mode tracing session.

      * Specify that `--output=DIR` is equivalent to

      Include the `--discard`, `--buffers-uid`, and `--buffers-global`
      options in the "SYNOPSIS" section even if they are the current

      Explain what this command does exactly using a tree of options
      and arguments.

      Clarify how LTTng finds tracing session configurations.

      * Document the missing `--group` option.

      * Rework the text in general.

      * Add a daemon configuration section with an INI file example.

      * Add more cross-references between options and equivalent
        environment variables.

      Specify that the `rotate-session` trigger action can also rotate
      a tracing session.

      Clarify the output path.

      Add more cross-references between options and equivalent
      environment variables.

      * Clarify everything related to the snapshot output of a tracing
        session, including when and how the lttng-create(1) command adds
        an initial snapshot output.

      * Specify that the `snapshot-session` trigger action can also take
        a snapshot of a tracing session.

      * Simply refer to allowing processes to record events and to
        process attribute inclusion sets instead of using the vague
        "tracker" terminology.

      * Restate that those commands control an implicit condition of
        a recording event rule, as per lttng-concepts(7).

      * Improve the documentation of each inclusion set selection

Signed-off-by: Philippe Proulx <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Iac7498ee979fe077f0927a9b8335f6c07f203989

20 months agodoc/man/manpage.xsl: do not indent the title of an admonition block
Philippe Proulx [Mon, 3 May 2021 19:46:51 +0000 (15:46 -0400)] 
doc/man/manpage.xsl: do not indent the title of an admonition block

See the new comment in `manpage.xsl` for more details.

I copied and modified some upstream DocBook XSL (as found in

Signed-off-by: Philippe Proulx <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I765ce37957907edb4088a4212c1b12af8b485e60

20 months agoFix: lttng: add-trigger: invalid access past end of exclusions buffer
Jérémie Galarneau [Thu, 29 Apr 2021 23:01:44 +0000 (19:01 -0400)] 
Fix: lttng: add-trigger: invalid access past end of exclusions buffer

The following command causes the `lttng` client to SEGFAULT on 32-bit
  lttng add-trigger \
    --condition event-rule-matches --domain=user \
                '--name=jean-*' \
                --exclude-name jean-chretien -x jean-charest \
    --action notify

Running with valgrind results in the following report:

Invalid read of size 8
   at 0x12EEA4: validate_exclusion_list (enable_events.c:354)
   by 0x149018: parse_event_rule (add_trigger.c:964)
   by 0x148356: handle_condition_event (add_trigger.c:1222)
   by 0x147EC3: parse_condition (add_trigger.c:1300)
   by 0x147702: cmd_add_trigger (add_trigger.c:2107)
   by 0x154067: handle_command (lttng.c:237)
   by 0x1534D1: parse_args (lttng.c:426)
   by 0x152C54: main (lttng.c:475)

validate_exclusion_list expects a NULL terminated array of exclusions
while handle_condition_event prepares an array of exclusions using
the dynamic pointer array facilities (which doesn't need to
null-terminate arrays).

The code that deals with exclusions "lists" mixes various conventions
(null-terminated vs explicit size) in different places leading to this
kind of errors.

All the code that references exclusion lists, along with the string
utils, are adapted to make use of the common dynamic pointer array

Signed-off-by: Jérémie Galarneau <>
Change-Id: Icbb7f0e8601c7ecc887dc9ae64d0ec6390e6aba3

20 months agoFix: tests: extra arguments are not passed to the remove trigger command
Jonathan Rajotte [Wed, 5 May 2021 17:34:00 +0000 (13:34 -0400)] 
Fix: tests: extra arguments are not passed to the remove trigger command

Observed issue
CI root jobs fails on the remove trigger operation for the user_trigger
trigger during the test_ust_notifier_discarded_count_multi_uid test.

The `--owner uid` option and its argument are not passed during the
command execution.

Pass all extra parameters for the command execution.

Known drawbacks


Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ic7b5d46b6793cda16a474c5459f9bf533812fe61

21 months agoFix: lttng-ctl: erroneous check if user is part of the tracing group
Jérémie Galarneau [Mon, 3 May 2021 16:50:25 +0000 (12:50 -0400)] 
Fix: lttng-ctl: erroneous check if user is part of the tracing group

in_tgroup is set to `-1` whenever the current user is not part of the
tracing group _or_ if an error occurred while looking up if the user
is part of the tracing group. In other words, the value '0' is unused.

in_tgroup must be explicitly checked against '1' and can't be assumed
to behave as a boolean value.

This is _not_ a security issue: if the user is not part of the tracing
group, she will fail to open the root session damon's socket because
of the kernel-side permission checking. However, the behaviour of the
lttng client (and error reporting) will be confusing.

Signed-off-by: Jérémie Galarneau <>
Change-Id: I614da0123d0546c5f54f121e8ed9716d6e292400

21 months agoBuild fix: kernel-consumerd: merge conflict left in file
Jérémie Galarneau [Mon, 3 May 2021 15:52:51 +0000 (11:52 -0400)] 
Build fix: kernel-consumerd: merge conflict left in file

Signed-off-by: Jérémie Galarneau <>
Change-Id: I71defaee6724a08661567af879b91a57d9dae74c

21 months agoClean-up: consumerd: use a specific status code for get_next_subbuffer
Jérémie Galarneau [Fri, 30 Apr 2021 16:12:44 +0000 (12:12 -0400)] 
Clean-up: consumerd: use a specific status code for get_next_subbuffer

The implementation of "get next subbuffer" of the user space and kernel
tracers return different error codes (-ENODATA and -EAGAIN) which are
are confusing to handle in the generic code.

Since the difference between -ENODATA and -EAGAIN makes no material
difference in the current consumerd implementation, those conditions
are abstracted by a common GET_NEXT_SUBBEFFER_STATUS_NO_DATA.

Otherwise, the callers handle 'OK' and the generic 'ERROR' condition
which makes the transport of more specific "errno" values useless for
the moment.

Signed-off-by: Jérémie Galarneau <>
Change-Id: Ibdb2837396e4b8cd291ffd80f6ca59b39ce3f707

21 months agoFix: kernel consumer: get next subbuffer EAGAIN handling
Mathieu Desnoyers [Fri, 30 Apr 2021 16:02:47 +0000 (12:02 -0400)] 
Fix: kernel consumer: get next subbuffer EAGAIN handling

The caller of get next subbuffer (data and metadata) callbacks only
expects -ENODATA when there is no data to read. However, the kernel
tracer distinguishes between no data for a finalized stream (-ENODATA)
and no data for a non-finalized stream (-EAGAIN).

Given that the consumer daemon uses the POLLHUP returned by epoll to
detect stream end of life, it does not care about the distinction
between -EAGAIN and -ENODATA when streaming.

However, taking a snapshot of a metadata stream uses the distinction
between nodata and again. Change this so it considers a return value of
0 from lttng_consumer_read_subbuffer to mean there is no more data to
read, so we can combine -EAGAIN and -ENODATA within get next subbuffer
callbacks and return -ENODATA for both.

Signed-off-by: Mathieu Desnoyers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I30786985c2389570dd342e55d4faf7c552532f8b

21 months agoFix: kernel consumer: signal metadata ready condition variable
Mathieu Desnoyers [Fri, 30 Apr 2021 14:44:44 +0000 (10:44 -0400)] 
Fix: kernel consumer: signal metadata ready condition variable

The behaviour of the kernel consumer does not match that of the user
space consumer. When a live metadata stream goes back to "sleep", it
must broadcast on the metadata_rdv to wake-up any thread that is
performing a metadata sync.

This mismatch causes a hang in the kernel consumer during the kernel
clear tests.

Signed-off-by: Mathieu Desnoyers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ief15fc2b7c92582ea36bf64d185720e48d2c94d5

21 months agoFix: consumerd: unbalanced subbuffer 'get' when checking operation availability
Jérémie Galarneau [Thu, 29 Apr 2021 20:17:45 +0000 (16:17 -0400)] 
Fix: consumerd: unbalanced subbuffer 'get' when checking operation availability

A WARN_ON in lttng-modules is hit in the get_subbuf ioctl, which
pointed to an unbalanced get/put pair when accessing the subbuffers
of a channel.

517716.168856] ------------[ cut here ]------------
[517716.171559] WARNING: CPU: 1 PID: 19313 at /home/efficios/git/lttng-modules/src/lib/ringbuffer/ring_buffer_frontend.c:1263 lib_ring_buffer_get_subbuf+0x24f/0x260 [lttng_lib_ring_buffer]
[517716.180096] Modules linked in: lttng_test(O) lttng_probe_x86_exceptions(O) lttng_probe_x86_irq_vectors(O) lttng_probe_writeback(O) lttng_probe_workqueue(O) lttng_probe_vmscan(O) lttng_probe_udp(O) lttng_probe_timer(O) lttng_probe_sunrpc(O) lttng_probe_statedump(O) lttng_probe_sock(O) lttng_probe_skb(O) lttng_probe_signal(O) lttng_probe_scsi(O) lttng_probe_sched(O) lttng_probe_regulator(O) lttng_probe_regmap(O) lttng_probe_rcu(O) lttng_probe_random(O) lttng_probe_printk(O) lttng_probe_power(O) lttng_probe_net(O) lttng_probe_napi(O) lttng_probe_module(O) lttng_probe_kmem(O) lttng_probe_jbd2(O) lttng_probe_irq(O) lttng_probe_i2c(O) lttng_probe_gpio(O) lttng_probe_ext4(O) lttng_probe_compaction(O) lttng_probe_btrfs(O) lttng_probe_block(O) lttng_counter_client_percpu_32_modular(O) lttng_counter_client_percpu_64_modular(O) lttng_counter(O) lttng_ring_buffer_event_notifier_client(O) lttng_ring_buffer_metadata_mmap_client(O) lttng_ring_buffer_client_mmap_overwrite(O)
[517716.180815]  lttng_ring_buffer_client_mmap_discard(O) lttng_ring_buffer_metadata_client(O) lttng_ring_buffer_client_overwrite(O) lttng_ring_buffer_client_discard(O) lttng_tracer(O) lttng_statedump(O) lttng_wrapper(O) lttng_uprobes(O) lttng_clock(O) lttng_kprobes(O) lttng_lib_ring_buffer(O) lttng_kretprobes(O) [last unloaded: lttng_wrapper]
[517716.213228] CPU: 1 PID: 19313 Comm: lttng-consumerd Tainted: G           O      5.11.2 #80
[517716.215573] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[517716.220341] RIP: 0010:lib_ring_buffer_get_subbuf+0x24f/0x260 [lttng_lib_ring_buffer]
[517716.222579] Code: 50 f0 ff 00 0f 0b 49 03 5f 28 44 8b 85 80 00 00 00 49 8b 77 30 45 85 c0 48 89 d9 0f 85 4f ff ff ff e9 25 ff ff ff f0 ff 45 00 <0f> 0b b8 f0 ff ff ff e9 a6 fe ff ff 0f 1f 44 00 00 0f 1f 44 00 00
[517716.227610] RSP: 0018:ffffbafd09023e88 EFLAGS: 00010202
[517716.229147] RAX: 0000000000000000 RBX: ffff9906ed069a00 RCX: ffff9905c4e4a400
[517716.231186] RDX: ffffdafcffc4ec90 RSI: 0000000000200000 RDI: ffffdafcffc4e9f0
[517716.233265] RBP: ffff9905c4e4a400 R08: 0000000000300000 R09: 0000000000200000
[517716.235284] R10: 0000000000200000 R11: 0000000000000000 R12: 0000000000000000
[517716.237333] R13: 0000000000000000 R14: 000000000000005e R15: 0000000000000000
[517716.239360] FS:  00007ff327fff700(0000) GS:ffff9905a7a40000(0000) knlGS:0000000000000000
[517716.241634] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[517716.243262] CR2: 000055b91cf07730 CR3: 000000076f45e003 CR4: 00000000001706e0
[517716.245316] Call Trace:
[517716.246281]  lib_ring_buffer_ioctl+0x181/0x300 [lttng_lib_ring_buffer]
[517716.248301]  lttng_stream_ring_buffer_ioctl+0x1a3/0x200 [lttng_tracer]
[517716.252621]  __x64_sys_ioctl+0x8e/0xd0
[517716.253931]  do_syscall_64+0x33/0x80
[517716.255016]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[517716.256448] RIP: 0033:0x7ff3372f46d7
[517716.257586] Code: b3 66 90 48 8b 05 b1 47 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 47 2d 00 f7 d8 64 89 01 48
[517716.262472] RSP: 002b:00007ff327ffe2c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[517716.264634] RAX: ffffffffffffffda RBX: 00007ff310002740 RCX: 00007ff3372f46d7
[517716.266674] RDX: 0000000000000000 RSI: 000000000000f605 RDI: 000000000000005e
[517716.268713] RBP: 00007ff327ffe310 R08: 00007ff310002870 R09: a002000000000000
[517716.270732] R10: 000055992b0a6530 R11: 0000000000000246 R12: 000055992c47da70
[517716.272768] R13: 00007ff318005e80 R14: 00007ff310002740 R15: 000055992b0a6528
[517716.274800] irq event stamp: 4526705
[517716.275897] hardirqs last  enabled at (4526713): [<ffffffff9016a474>] console_unlock+0x4b4/0x5b0
[517716.278320] hardirqs last disabled at (4526722): [<ffffffff9016a3d0>] console_unlock+0x410/0x5b0
[517716.280759] softirqs last  enabled at (4526658): [<ffffffff9120030f>] __do_softirq+0x30f/0x432
[517716.285125] softirqs last disabled at (4526653): [<ffffffff91001052>] asm_call_irq_on_stack+0x12/0x20
[517716.287648] ---[ end trace 506e55b312b731bf ]---

The check for the availability of the 'get_next_check_metadata'
operation attempts to use the operation at the creation of the metadata
stream. Most of the time this occurs before any metadata could be

However, the check will sometimes (very rarely) occur after the
generation of some metadata causing the 'get' to succeed and,
consequently, a subbuffer to be acquired. In those cases, the subbuffer
must be released immediately.

Fixes #1313

Signed-off-by: Jérémie Galarneau <>
Change-Id: I906dca7d83ce103c009aa477ae5881145e4aa081

21 months agosessiond: remove commented-out logging
Jérémie Galarneau [Wed, 28 Apr 2021 21:50:41 +0000 (17:50 -0400)] 
sessiond: remove commented-out logging

Signed-off-by: Jérémie Galarneau <>
Change-Id: I7b8991ba994585fd8f2b5c6e02b9be7cf8e7123b

21 months agosessiond: Remove [.*-thread] logging prefix
Jérémie Galarneau [Wed, 28 Apr 2021 21:44:52 +0000 (17:44 -0400)] 
sessiond: Remove [.*-thread] logging prefix

The logger now logs the thread name making this prefix useless.

Signed-off-by: Jérémie Galarneau <>
Change-Id: Ie9093e4032d2cf0d3c0e9fa0d7eda28467033931

21 months agorun-as: reduce verbosity of fd sending error paths
Francis Deslauriers [Mon, 26 Apr 2021 22:18:11 +0000 (18:18 -0400)] 
run-as: reduce verbosity of fd sending error paths


A testcase in `tests/regression/tools/save-load/test_save` tests that
saving a session on an already existing configuration file fails.

The test case fails as expected but it is a bit noisy in terms of error
  ok 9 - Enable channel chan-save for session save-42
  ok 10 - Enable ust event tp:tptest for session save-42
  Error: Attempt to send invalid file descriptor to master (fd = -1)
  PERROR - 09:57:10.893683118 [Client management]: Could not create configuration file: File exists (in save_session() at save.c:2706)
  PERROR - 09:57:10.893714862 [Main]: Failed to close result file descriptor: Bad file descriptor (in send_fds_to_master() at runas.c:824)
  ok 11 - Session failed to be saved. Expected!

We see that 3 error statements are printed by the sessiond but only the
second is really relevant.


This commit:
- changes the first `ERR()` statement to a `DBG()` statement, and
- only call `close()` on seemingly valid FDs.


This commit also removes the mention of "master" in the first `DBG()`
statement as this function is used by both the master and the runas

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ie77d44233a770610f8a3f4412b84c0fd70c0812e

21 months agoSet thread name of run-as worker process
Francis Deslauriers [Mon, 26 Apr 2021 22:09:54 +0000 (18:09 -0400)] 
Set thread name of run-as worker process

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ifd89ad19a17d96975f712bcd298588f2fc28d04f

21 months agoUse new ioctl macros with fixed ioctl direction
Francis Deslauriers [Tue, 27 Apr 2021 18:26:09 +0000 (14:26 -0400)] 
Use new ioctl macros with fixed ioctl direction

Update the ioctl commands to follow the changes in this commit:
  commit 8c71721f7a868b575b05e24bc3a3dcc967e6d5d6
  Author: Mathieu Desnoyers <>
  Date:   Tue Apr 20 11:05:19 2021 -0400

      Fix: LTTng-modules ABI ioctl wrong direction

This commit uses the new command first, and if -ENOSYS is returned by
the LTTng kernel tracer it falls back to the old command.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I2604ea5902fec3bf574c7a249cb65784685a0ae8

21 months agoSync lttng-modules ABI in internal kernel-ioctl.h
Francis Deslauriers [Tue, 27 Apr 2021 16:13:57 +0000 (12:13 -0400)] 
Sync lttng-modules ABI in internal kernel-ioctl.h

This commit bumps the modules minor version number in `kernel-ioctl.h`
and applies the following renames:

define renames:

struct renames:
  `struct lttng_kernel_x` -> `struct lttng_kernel_abi_x`

No behavior change intended.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I0bb0ac6bca56b6740ea2d543a6d1bd618d39b36c

21 months agoFix: data reception is called event when only FDS are expected for reception
Jonathan Rajotte [Tue, 27 Apr 2021 01:09:35 +0000 (21:09 -0400)] 
Fix: data reception is called event when only FDS are expected for reception

In non blocking mode, the FDs reception code can hit EAGAIN. In such
cases, skip the data reception completely when performing the reception.

The same behavior could have been implemented with a noop at the
`lttcomm_recv_unix_sock_non_block` level when the passed `len` is equal
to 0. The handling of it at the notification thread reception level was
chosen to be explicit with regards to the expected behaviour and not
rely on implicit functionality of `lttcomm_recv_unix_sock_non_block`.

While there, augment assertions for code in unix.c

Change-Id: I0fa6df1c9630caa6e877a39372bdfd3d3a01b648
Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
21 months agoFix: FDs are added to payload despite not being received
Jonathan Rajotte [Tue, 27 Apr 2021 01:08:18 +0000 (21:08 -0400)] 
Fix: FDs are added to payload despite not being received

`lttcomm_recv_fds_unix_sock_non_block` can return zero on EAGAIN.

It is important not to add the raw_fds array to the payload in such case
since concretely no FDs have been received.

Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I551457856c885098bf0de2388936e97456051f93

21 months agoFix: initialize temporary fd array element to -1
Jonathan Rajotte [Tue, 27 Apr 2021 01:07:08 +0000 (21:07 -0400)] 
Fix: initialize temporary fd array element to -1

These are FDs, an initialization value of zero is a valid FD number
hence we must initialize the element to -1.

This allows us to be more strict in `add_fds_to_payload` and assert that
the passed FDs are actual FDs and not only bare zero-initialized

Change-Id: Icc05d98d51906636362a67588d7c42b58cf33ded
Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
21 months agoFix: common: hide shm* util symbols
Jérémie Galarneau [Mon, 26 Apr 2021 23:21:53 +0000 (19:21 -0400)] 
Fix: common: hide shm* util symbols

Internal symbols that are part of libcommon must be marked as "hidden".
Otherwise, the symbols are exported as part of

Signed-off-by: Jérémie Galarneau <>
Change-Id: I41e7746a8044e85a7d422f138654de1579bf22f1

21 months agoFix: mark channel as disabled even if the session is inactive
Francis Deslauriers [Thu, 25 Feb 2021 23:19:37 +0000 (18:19 -0500)] 
Fix: mark channel as disabled even if the session is inactive

Observed issue
When the session is stopped, disable-channel commands are no-op.

The following commands reproduce the issue:
  lttng create
  lttng enable-event -u -a
  lttng start
  sleep 4
  lttng stop

  lttng disable-channel -u channel0
  sleep 10
  lttng start
  sleep 4
  lttng stop

  lttng view

Note that the sleep command there are to give the UST application time
to produce events.

Even after disabling the channel, we can see that events are still

This is due to the fact that the `channel_ust_disable()` function
returns early if the session is inactive and omits to set the channel as

Proposed fix
Move this following line before the check:
uchan->enabled = 0;

Add a test case to exercise this exact scenario.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I9660064ac6eb99f2aea8851dc98a94cfc1b810e6

21 months agoFix: condition: buffer-usage: use double instead of fixed point
Francis Deslauriers [Fri, 23 Apr 2021 18:45:31 +0000 (14:45 -0400)] 
Fix: condition: buffer-usage: use double instead of fixed point

Issue observed

When running the test_notification_ust_buffer_usage test on x86
(32 bit), the session daemon and test client both crash. The session
daemon dies while attempting to lock a NULL client list during the
execution of an enqueued action in the action executor.

See the following backtrace:

 #0  0xf7c6c756 in __GI___pthread_mutex_lock (mutex=0x0) at ../nptl/pthread_mutex_lock.c:67
 #1  0x565afe96 in notification_client_list_send_evaluation (client_list=0x0, trigger=0xf0f225e0, evaluation=0xf330c830, source_object_creds=0xf330e5cc, client_report=0x565cf81b <client_handle_transmission_status>, user_data=0xf330c320) at notification-thread-events.c:4372
 #2  0x565cfb41 in action_executor_notify_handler (executor=0xf330c320, work_item=0xf330e5b0, item=0xf330c7b0) at action-executor.c:269
 #3  0x565d1a58 in action_executor_generic_handler (executor=0xf330c320, work_item=0xf330e5b0, item=0xf330c7b0) at action-executor.c:696
 #4  0x565d1b7f in action_work_item_execute (executor=0xf330c320, work_item=0xf330e5b0) at action-executor.c:715
 #5  0x565d212f in action_executor_thread (_data=0xf330c320) at action-executor.c:797
 #6  0x565b9d0e in launch_thread (data=0xf330c390) at thread.c:66
 #7  0xf7c69fd2 in start_thread (arg=<optimized out>) at pthread_create.c:486
 #8  0xf7b7f6d6 in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:108

This crash causes an assertion to fail in the test client; checking for
data pending was not expected to return a negative value. In this case,
the negative return value is justified as it is -LTTNG_ERR_NO_SESSIOND.


Equipped with coffee, a debugger, and a healthy dose of print
statements, it appeared that the following was taking place:

- Register a trigger (T1): high buffer usage (0.99) -> notify (succeeds)
- Subscribe to high buffer usage (0.99) notifications (succeeds)
- Subscribe to high buffer usage (0.99) notifications
  (fails duplicate, expected)
- Unregister trigger (fails unexpectedly)
- Notification client destroys its channel, causing the condition to be

- Another test registers a trigger (T2): high buffer usage (0.90) ->
  notify (succeeds)
- Session daemon evaluates a channel sample against T1's condition,
  which evaluates to true and produces an "evaluation" to send to
- The client list associated to T1's condition is not found (but this
  isn't checked)
- An action executor work item is queued to run T1's actions (notify),
  but without a client list, resulting in the crash when it is executed.

We could confirm that the client list associated to T1's condition was
created and never destroyed making the failure to find it rather

It turns out that the hash of T1's condition did not match the hash of
the client list's condition. This is unexpected as both conditions are
copies of one another.

It turns out that, on x86, the scheme being used to transmit the
condition's buffer usage threshold floating point value is not compiled
to numerically stable code. Serializing such a buffer condition and
creating it from the resulting payload in a loop showed that the
threshold value gradually drifted. This isn't the case on the other
architectures we support.

On x86-64, gcc makes use of SSE instructions to perform the conversion
to an integral value (with double precision). However, on x86, it makes
use of the x87 fpu stack instructions which carry 80-bit of precision
internally, resulting in a loss of precision as the value is
transformed, back and forth, between 80-bit to double precision


Since conditions are not carried between hosts (only between clients
and the session daemon), a fixed-point conversion scheme is unnecessary.
The 'double' value provided by the client is carried directly which
bypasses the problem completely.



Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ie524e7362626406327f4f56e1dba5c8cf469df31

21 months agoTests: notification: fail on trigger unregistration failure
Jérémie Galarneau [Wed, 28 Apr 2021 17:16:12 +0000 (13:16 -0400)] 
Tests: notification: fail on trigger unregistration failure

Signed-off-by: Jérémie Galarneau <>
Change-Id: I474c92f34604100081676dda484513cc8a950c73

21 months agoUpdate version to v2.13.0-rc1
Jérémie Galarneau [Sat, 24 Apr 2021 01:28:58 +0000 (21:28 -0400)] 
Update version to v2.13.0-rc1

Signed-off-by: Jérémie Galarneau <>
21 months agoSet the 2.13 release codename and description
Jérémie Galarneau [Fri, 23 Apr 2021 15:21:13 +0000 (11:21 -0400)] 
Set the 2.13 release codename and description

Signed-off-by: Jérémie Galarneau <>
Change-Id: I6d388b879bc10f5fd5d869352a90701faa20a378

21 months agoTests: fix: test_notification_notifier_discarded_count missing renames
Jérémie Galarneau [Fri, 23 Apr 2021 22:30:22 +0000 (18:30 -0400)] 
Tests: fix: test_notification_notifier_discarded_count missing renames

Some options of lttng-add-trigger were renamed without adapting the
test since that part is only ran when destructive tests are enabled.

Signed-off-by: Jérémie Galarneau <>
Change-Id: Ia5b01e64a3766adced292be7f7436d742b3308c7

21 months agoDocs: lttng-add-trigger and lttng-remove-trigger refer to owner-id
Jérémie Galarneau [Fri, 23 Apr 2021 22:29:29 +0000 (18:29 -0400)] 
Docs: lttng-add-trigger and lttng-remove-trigger refer to owner-id

The proper name of the option is --owner-uid.

Signed-off-by: Jérémie Galarneau <>
Change-Id: I8db096acc5ddd06107762a44ebfda8eaf96ba0d4

21 months agoFix: tests: test case using old condition syntax
Francis Deslauriers [Fri, 23 Apr 2021 21:15:28 +0000 (17:15 -0400)] 
Fix: tests: test case using old condition syntax

This commit also changes "on-event" -> "event-rule-matches"

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I0b9ff1302ca5a3e8bbdddc8a626890c527dcbd59

21 months agolttng-add-trigger(1): clarify the `--rate-policy` documentation
Philippe Proulx [Fri, 23 Apr 2021 21:12:12 +0000 (17:12 -0400)] 
lttng-add-trigger(1): clarify the `--rate-policy` documentation

Signed-off-by: Philippe Proulx <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I6144521f3186e33c52d7ac20b64cf3e8f7663a55

21 months agoUpdate some manual pages for LTTng-tools 2.13
Philippe Proulx [Wed, 3 Mar 2021 20:18:30 +0000 (15:18 -0500)] 
Update some manual pages for LTTng-tools 2.13

This patch updates some manual pages for LTTng-tools 2.13. A few pages
still remain to be updated, a task which is reserved for a subsequent

This patch:

* Improves the consistency of the the command descriptions in

* Adds `common-help-option.txt` which is the description of any
  `--help` option.

* Adds `common-intro.txt` which is a common description introduction for
  the top-level manual pages.

* Adds `lttng-event-rule.7.txt` which describes the common way to
  specify an event rule on the command-line.

  lttng-event-rule(7) has a "Migration from a recording event rule
  specification" section with a table which shows the relationship
  between lttng-enable-event(1) command-line arguments and
  lttng-event-rule(7) options.

  As of this patch, only `lttng-add-trigger.1.txt` references it,
  for the `event-rule-matches` trigger condition.

  `` is also updated to build and include manual pages of
  section 7.

* Updates existing manual pages to:

  * Have a style and voice which is more consistent with the
    LTTng Documentation (website) for 2.13.

  * Fix various terminology ambiguities.

  * Use more textual variables and lists to explain more complex logic
    and processes.

  More specifically:

      Specify that this command adds context fields to be recorded
      to the event records of one or more channels.

      In other words, this is a recording-related command. You don't
      need to use it to access context fields with the filter expression
      of an event rule, for example.

      * Update the "NAME" section.

      * Add internal option links where missing.

      * Improve the description.

        Add links to the lttng-remove-trigger(1) and
        lttng-list-triggers(1) manual pages and explain what those
        commands are used for.

        Use "condition specifier" and "action specifier" terms to
        describe those groups of options.

        For condition and action specifiers, use localized synopses.

        For action specifiers, add links to the corresponding LTTng
        command manual pages.

      * Document the `--owner-id` option.

      * Group option descriptions.

      * Use "name" instead of "ID".

      * Refer to the new lttng-event-rule(7) manual page.

      * Remove the "no context field" limitation for `ERSPEC`.

      * Fix verse blocks nested in lists.

      * Add more documentation about tracing sessions.

      * Specify that the `create` command can spawn a session daemon.

      * Add the "Current tracing session" section to explain this
        concept and where it applies.

      * Clarify the "URL format" section.

      Explain how this command can only find recording event rules
      to disable by instrumentation point type and event name condition.

      I more or less completely rewrote this page.

      The document now clearly explains the related core concepts, shows
      the explicit and implicit conditions of a recording event rule,
      has one section for each condition explaining how an event can
      satisfy it, and more.

      The synopsis is more accurate.

      I added an "Event record name" section to indicate what's the name
      of a matched event depending on the instrumentation point type and
      some command-line arguments.

      I also added an "Enable a disabled recording event rule" section
      to explain how the `enable-event` command enables existing,
      disabled events.

      This manual page now documents all the options, even if they're
      the default, as defaults may change in the future.

      The new lttng-event-rule(7) manual page is based on this one, but
      with its own ways to specify event rule conditions.

      * Use "name" instead of "ID".
      * Use `--owner-id` instead of `--user-id`.

      * Explain what an LTTng session daemon does.

      * Clarify everything related to the tracing group and root
        session daemon.

      * Add a "Daemon configuration" section which explains the
        INI configuration files and the `--config` option.

      * Make the "Tracing session configuration loading" section
        (renamed) much more straightforward, with less text.

      * Specify that the `--daemonize` and `--background` options
        make `lttng-sessiond` only exit when the daemon is ready to
        receive client commands.

      List which commands rely on the current tracing session

      * Add a "Session daemon connection" section which shows how the
        `lttng` tool (or any LTTng tracing control application) connects
        to a session daemon (user-specific vs. root session daemon).

      * Use tables to list the available commands.

Signed-off-by: Philippe Proulx <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I6b98f4907d94763f3bfcb6576e4add9cfc59a2e3

21 months ago.gitignore: add register-some-triggers trigger test utility
Jérémie Galarneau [Fri, 23 Apr 2021 20:21:08 +0000 (16:21 -0400)] 
.gitignore: add register-some-triggers trigger test utility

Signed-off-by: Jérémie Galarneau <>
Change-Id: Iba2ccd5d23e90a421386d1ff81cde71fcbbe72fd

21 months agoFix: event-expr.c: use-after-free and NULL ptr deref in error path
Francis Deslauriers [Thu, 22 Apr 2021 22:50:57 +0000 (18:50 -0400)] 
Fix: event-expr.c: use-after-free and NULL ptr deref in error path

The following functions are affected:
  `lttng_event_expr_app_specific_context_field_create()`, and

In one error path we call `lttng_event_expr_destroy()` with the
`&expr->parent` pointer (which is dynamically allocated) and this
function then calls free() on that pointer. Right after that function
call we return the pointer that was just freed.

Fix that by adding a `ret_parent_expr` pointer that is set to NULL on
the error path;

Null pointer dereference
The following functions are affected:
  `lttng_event_expr_array_field_element_create()`, and

We dereference a NULL pointer if the argument sanity check fails.

Fix that by checking if `expr` is non-null before dereferencing it.

Found with scan-build.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I5fdde462d7345d0dae7ecd2e4f46473a92cd11a9

21 months agoAdapt to namespaced liblttng-ust-ctl symbols
Michael Jeanson [Thu, 22 Apr 2021 22:46:06 +0000 (18:46 -0400)] 
Adapt to namespaced liblttng-ust-ctl symbols

The liblttng-ust ABI bump gave us the opportunity to namespace all
public symbols under the 'lttng_ust_' prefix. All of liblttng-ust-ctl
public symbols were renamed from 'ustctl_' to 'lttng_ust_ctl_'. Adapt
the tools codebase for this API change.

Depends-on: lttng-ust: Ic2b9da019e7776b24b98824ae63d16b86c5a5742

Change-Id: I64b61a7fad86a1c0b4734a4a181f6ea7a9de7e24
Signed-off-by: Michael Jeanson <>
Signed-off-by: Jérémie Galarneau <>
21 months agoCleanup: ust-app.c: Dead assignment
Francis Deslauriers [Thu, 22 Apr 2021 21:39:33 +0000 (17:39 -0400)] 
Cleanup: ust-app.c: Dead assignment

Found using scan-build.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I8920ee21d8202e9b94b95f517c8e1fbe8c9224a0

21 months agoFix: tests: gen-ust-events-ns: Uninitialized argument value
Francis Deslauriers [Thu, 22 Apr 2021 21:24:57 +0000 (17:24 -0400)] 
Fix: tests: gen-ust-events-ns: Uninitialized argument value

If both `if (snprintf(...` of the `get_ns_inum()` function fail, the
function will not uninitialize the `ns_inum` output parameter and still
return 0. Leading to the argument `ns1` of debug_printf() being used

Reported-by: scan-build.
Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I47286312095ca0f6a889eb0faa93661f92156ec1

21 months agoFix: consumerd: strlen called on uninitialized path
Jérémie Galarneau [Thu, 22 Apr 2021 23:54:47 +0000 (19:54 -0400)] 
Fix: consumerd: strlen called on uninitialized path

closed_trace_chunk_path is uninitialized when relayd_id != 0.

Signed-off-by: Jérémie Galarneau <>
Change-Id: Ica3763e5e73a9f2796b96c8030c551e730fe63d8

21 months agoFix: sessiond: notification: leak of condition on duplicate subscription
Jérémie Galarneau [Thu, 22 Apr 2021 23:33:02 +0000 (19:33 -0400)] 
Fix: sessiond: notification: leak of condition on duplicate subscription

An lttng_condition is leaked when a notification channel client attempts
to subscribe to a condition she is already subscribed to.

Signed-off-by: Jérémie Galarneau <>
Change-Id: I3474ba07046c75bc3cfc2c32501d77b3ea880d33

21 months agoFix: action executor: deadlock on session_list_lock
Jonathan Rajotte [Thu, 22 Apr 2021 02:01:02 +0000 (22:01 -0400)] 
Fix: action executor: deadlock on session_list_lock

Observed issue

A dead lock is observed during the start-stop test suite for triggers.


A start session action is executed by the action executor, the
`cmd_start_trace` function is called and effectively holds the
`session_list_lock.`. During `cmd_start_trace` a call to
`notification_thread_command_add_channel` is performed to inform the
notification thread of the new channel presence.

At the same time, a tracer event notification is received by the
notification thread. The actions are queued up and the sample of the
session id take place and a call to `session_lock_list` is performed and
blocks on the lock operation.

The notification thread wait on the `session_list_lock` and the
`session_list_lock` holder, the action executor, waits on the completion
of a command the be run by the notification thread: deadlock.

The backtrace:

 Thread 6 (Thread 0x7f831c8a6700 (LWP 3046458)):
 #0  syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
 #1  0x000000000053b852 in futex (uaddr=0x7f831c8a45e0, op=0, val=0, timeout=0x0, uaddr2=0x0, val3=0) at /home/joraj/lttng/master/install/include/urcu/futex.h:72
 #2  0x000000000053b4f9 in futex_noasync (uaddr=0x7f831c8a45e0, op=0, val=0, timeout=0x0, uaddr2=0x0, val3=0) at /home/joraj/lttng/master/install/include/urcu/futex.h:81
 #3  0x000000000053af10 in lttng_waiter_wait (waiter=0x7f831c8a45d8) at waiter.c:55
 #4  0x000000000046b0f2 in run_command_wait (handle=0xe60520, cmd=0x7f831c8a4588) at notification-thread-commands.c:49
 #5  0x000000000046b270 in notification_thread_command_add_channel (handle=0xe60520, session_name=0x7f8300006c30 "my_triggered_session", uid=1000, gid=1000, channel_name=0x7f82dc00be04 "channel0", key=1, domain=LTTNG_DOMAIN_UST, capacity=2097152) at notification-thread-commands.c:184
 #6  0x00000000004c7f65 in create_channel_per_uid (app=0x7f82d8000bf0, usess=0x7f8300000bb0, ua_sess=0x7f82dc002600, ua_chan=0x7f82dc00bde0) at ust-app.c:3360
 #7  0x00000000004c6f98 in ust_app_channel_send (app=0x7f82d8000bf0, usess=0x7f8300000bb0, ua_sess=0x7f82dc002600, ua_chan=0x7f82dc00bde0) at ust-app.c:3514
 #8  0x00000000004c6bde in ust_app_channel_create (usess=0x7f8300000bb0, ua_sess=0x7f82dc002600, uchan=0x7f8300005a90, app=0x7f82d8000bf0, _ua_chan=0x7f831c8a48b0) at ust-app.c:4771
 #9  0x00000000004c6968 in find_or_create_ust_app_channel (usess=0x7f8300000bb0, ua_sess=0x7f82dc002600, app=0x7f82d8000bf0, uchan=0x7f8300005a90, ua_chan=0x7f831c8a48b0) at ust-app.c:5610
 #10 0x00000000004c4f09 in ust_app_synchronize_all_channels (usess=0x7f8300000bb0, ua_sess=0x7f82dc002600, app=0x7f82d8000bf0) at ust-app.c:5820
 #11 0x00000000004b958c in ust_app_synchronize (usess=0x7f8300000bb0, app=0x7f82d8000bf0) at ust-app.c:5886
 #12 0x00000000004b8500 in ust_app_global_update (usess=0x7f8300000bb0, app=0x7f82d8000bf0) at ust-app.c:5960
 #13 0x00000000004b7ec2 in ust_app_start_trace_all (usess=0x7f8300000bb0) at ust-app.c:5520
 #14 0x0000000000444e86 in cmd_start_trace (session=0x7f8300006c30) at cmd.c:2707
 #15 0x00000000004a5af9 in action_executor_start_session_handler (executor=0x7f8314004410, work_item=0x7f8314005100, item=0x7f83140050b0) at action-executor.c:342
 #16 0x00000000004a537f in action_executor_generic_handler (executor=0x7f8314004410, work_item=0x7f8314005100, item=0x7f83140050b0) at action-executor.c:696
 #17 0x00000000004a4dbc in action_work_item_execute (executor=0x7f8314004410, work_item=0x7f8314005100) at action-executor.c:715
 #18 0x00000000004a37e6 in action_executor_thread (_data=0x7f8314004410) at action-executor.c:797
 #19 0x0000000000486193 in launch_thread (data=0x7f83140044b0) at thread.c:66
 #20 0x00007f8320b60609 in start_thread (arg=<optimized out>) at pthread_create.c:477
 #21 0x00007f8320a87293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

 Thread 5 (Thread 0x7f831d0a7700 (LWP 3046457)):
 #0  __lll_lock_wait (futex=futex@entry=0x5e1c10 <ltt_session_list>, private=0) at lowlevellock.c:52
 #1  0x00007f8320b630a3 in __GI___pthread_mutex_lock (mutex=0x5e1c10 <ltt_session_list>) at ../nptl/pthread_mutex_lock.c:80
 #2  0x00000000004378c3 in session_lock_list () at session.c:156
 #3  0x00000000004a871c in add_action_to_subitem_array (action=0x7f830001a730, subitems=0x7f83140051d0) at action-executor.c:1081
 #4  0x00000000004a8578 in add_action_to_subitem_array (action=0x7f830001a620, subitems=0x7f83140051d0) at action-executor.c:1025
 #5  0x00000000004a4922 in populate_subitem_array_from_trigger (trigger=0x7f830001a950, subitems=0x7f83140051d0) at action-executor.c:1116
 #6  0x00000000004a416e in action_executor_enqueue_trigger (executor=0x7f8314004410, trigger=0x7f830001a950, evaluation=0x7f8314005190, object_creds=0x0, client_list=0x7f8314004980) at action-executor.c:924
 #7  0x0000000000479481 in dispatch_one_event_notifier_notification (state=0x7f831d0a63e8, notification=0x7f8314005160) at notification-thread-events.c:4613
 #8  0x0000000000472324 in handle_one_event_notifier_notification (state=0x7f831d0a63e8, pipe=65, domain=LTTNG_DOMAIN_UST) at notification-thread-events.c:4702
 #9  0x0000000000472271 in handle_notification_thread_event_notification (state=0x7f831d0a63e8, pipe=65, domain=LTTNG_DOMAIN_UST) at notification-thread-events.c:4717
 #10 0x00000000004695a3 in handle_event_notification_pipe (event_source_fd=65, domain=LTTNG_DOMAIN_UST, revents=1, state=0x7f831d0a63e8) at notification-thread.c:591
 #11 0x000000000046849b in thread_notification (data=0xe60520) at notification-thread.c:727
 #12 0x0000000000486193 in launch_thread (data=0xe60610) at thread.c:66
 #13 0x00007f8320b60609 in start_thread (arg=<optimized out>) at pthread_create.c:477
 #14 0x00007f8320a87293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95


Instead of using session_find_by_name() which requires the
`session_list_lock`, we introduce `sample_session_id_by_name` that uses
a urcu backed data structure. This allows the sampling of the session
id without holding the session list lock. We accept the small window
where a session object is still accessible but concretely not valid
since the actual execution context will be validated at the moment of
execution. The execution side already handles the possibility that the
session is removed at that point or is not the same session. The
execution side acquires the session_list_lock for validation.

Known drawbacks


Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I5ad2c57acc0d03d2814dda59f8ecf2d831fd961e

21 months agolttng add-trigger: replace --exclude-names with --exclude-name
Simon Marchi [Tue, 20 Apr 2021 02:13:28 +0000 (22:13 -0400)] 
lttng add-trigger: replace --exclude-names with --exclude-name

Implement the proposal to make the --exclude-names option singular. The
user can specify it multiple times to specify multiple exclusions,
rather than specifying a comma-separated list.

Change-Id: Id95313bb5576a8d6cecb73b61b537ae190554cd0
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agosessiond: refcount `ust_error_accounting_entry`
Francis Deslauriers [Fri, 16 Apr 2021 15:14:21 +0000 (11:14 -0400)] 
sessiond: refcount `ust_error_accounting_entry`

Keep a reference count of the `ust_error_accounting_entry` to reclaim
memory and cleanup handles as we go.

Triggers on a sessiond target all applications regardless of the UID of
both the trigger and the application. This means that whenever a new UST
counter is created for a UID, we need to keep it around as long as there
is 1. an application from that UID, or 2. an event notifier registered.

This commit achieves that by keeping a count of the registered event
notifiers. If the count is above zero, we keep a reference on every UID
entries. When the count reaches zero, we put that reference on every

The event notifier count is guarded by a mutex since it's accessed by
both the notification thread and UST registration thread.

Here is the pseudo code for the relevant error accounting events:
App registration:
  lookup entry for application UID in hashtable
  if found:
    get a reference on that existing entry
    create a new entry for that UID
    get a reference on that new entry
    if event_notifier_count > 0:
      get an extra reference on the behalf of the event notifiers

Event notifier registration:
  increment event_notifier_count
  if event_notifier_count == 1:
    get a reference on all existing UID entries

App unregistration:
  put reference on application UID entry

Event notifier unregistration:
  decrement event_notifier_count
  if event_notifier_count == 0:
    put ref on all existing UID entries

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I74667d30a5b6975bad7975b82f6819e263199cd0

21 months agoaction list: missing renames from previous name "group"
Jérémie Galarneau [Thu, 22 Apr 2021 18:56:59 +0000 (14:56 -0400)] 
action list: missing renames from previous name "group"

Signed-off-by: Jérémie Galarneau <>
Change-Id: I9b7379d5f2ed66677666365cf5cf0b98c774f219

21 months agoFix: error-query: uninitialized action_index value
Jérémie Galarneau [Thu, 22 Apr 2021 18:50:55 +0000 (14:50 -0400)] 
Fix: error-query: uninitialized action_index value

action_index will be used uninitialized if the user passes an action
that is not part of the trigger (an API use error).

CID 1452662 (#2 of 2): Uninitialized scalar variable (UNINIT)
14. uninit_use: Using uninitialized value action_index.is_set.

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <>
Change-Id: I9afc6730b5462f4bf55e0dba3454efb5b4ca22c9

21 months agoFix: sessiond: leak of config_path on duplicate --config option
Jérémie Galarneau [Thu, 22 Apr 2021 18:47:14 +0000 (14:47 -0400)] 
Fix: sessiond: leak of config_path on duplicate --config option

1452207 Resource leak

The system resource will not be reclaimed and reused, reducing the
future availability of the resource.

CID 1452373 (#3 of 3): Resource leak (RESOURCE_LEAK)
26. overwrite_var: Overwriting config_path in config_path =
utils_expand_path(optarg) leaks the storage that config_path points to.

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <>
Change-Id: I70eff0f4de5ac9b84b699e88232669259eab54db

21 months agoFix: tests: base notification client: unchecked sscanf return value
Jérémie Galarneau [Thu, 22 Apr 2021 18:43:02 +0000 (14:43 -0400)] 
Fix: tests: base notification client: unchecked sscanf return value

CID 1407934 (#2 of 2): Unchecked return value (CHECKED_RETURN)
8. check_return: Calling sscanf without checking return value (as is
done elsewhere 17 out of 19 times).

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ifcef490aa15aea8ae4846553fbc63c596583d274

21 months agoFix: argpar: Error out when passing an argument to long option that takes no argument
Simon Marchi [Fri, 9 Apr 2021 16:48:30 +0000 (12:48 -0400)] 
Fix: argpar: Error out when passing an argument to long option that takes no argument

If the user defines a long option `--foo` and passes `--foo=arg`, the
current behavior is that the option foo is recognized and the argument
is ignored.  Change that to be an error.

It is currently not possible to pass arguments to short options using an
equal sign, so this doesn't apply to short options.

Equivalent accepted change in argpar:

Change-Id: I6fd6271abb7e271704db1e60f680729931a1fbe1
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agoClean-up: sessiond: identation fix
Jérémie Galarneau [Thu, 22 Apr 2021 16:37:37 +0000 (12:37 -0400)] 
Clean-up: sessiond: identation fix

Signed-off-by: Jérémie Galarneau <>
Change-Id: I10e56e226c7ea3eb6eae6a2ea17f5eae7cff3b6c

21 months agoFix: tests: health thread stall: only stop consumerd when required
Jérémie Galarneau [Thu, 22 Apr 2021 16:32:26 +0000 (12:32 -0400)] 
Fix: tests: health thread stall: only stop consumerd when required

Since a0f8e3109, stop_lttng_consumerd will report a failure when
there is no consumer daemon to kill. This fix ensures it is only
invoked for tests that launch a consumer daemon.

Signed-off-by: Jérémie Galarneau <>
Change-Id: I6831fbe7563d2e1804f10588494d126fbb4202ff

21 months agoFix: tests: notification: update kernel testcase count
Francis Deslauriers [Thu, 22 Apr 2021 15:07:26 +0000 (11:07 -0400)] 
Fix: tests: notification: update kernel testcase count

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ib65e4ea8ced397bdd3b30f1401121adbfeeff23a

21 months agoFix: tests: integer truncation warning on 32-bit platforms
Jérémie Galarneau [Thu, 22 Apr 2021 14:17:04 +0000 (10:17 -0400)] 
Fix: tests: integer truncation warning on 32-bit platforms

large integer implicitly truncated to unsigned type [-Woverflow]

Signed-off-by: Jérémie Galarneau <>
Change-Id: I3e479d240c25550f44bbf40944484870da85a401

21 months agoFix: sessiond: triggers: failure to insert trigger is fatal
Jérémie Galarneau [Wed, 21 Apr 2021 04:41:09 +0000 (00:41 -0400)] 
Fix: sessiond: triggers: failure to insert trigger is fatal

Inserting a trigger by name/owner should succeed if it could be added
to the top-level triggers_ht.

Signed-off-by: Jérémie Galarneau <>
Change-Id: I46518b86b34cb13074723b4f2bef38026d898700

21 months agosessiond: notification-thread: switch logging to debug on GET_TRIGGER
Jérémie Galarneau [Wed, 21 Apr 2021 03:57:11 +0000 (23:57 -0400)] 
sessiond: notification-thread: switch logging to debug on GET_TRIGGER

Not finding a trigger is not necessarily an error (espeacially during
the execution of tests).

Signed-off-by: Jérémie Galarneau <>
Change-Id: I238e6ca42f65e773e7e88773bc2e4f54b0a78ad5

21 months agoTests: add trigger name/unnamed backwards compatibility test
Jérémie Galarneau [Mon, 19 Apr 2021 21:44:55 +0000 (17:44 -0400)] 
Tests: add trigger name/unnamed backwards compatibility test

Signed-off-by: Jérémie Galarneau <>
Change-Id: Ib19de93e316640fb9ba37d2df621c3c97cd712f6

21 months agolttng-ctl: separate support of named/unnamed trigger registration
Jérémie Galarneau [Tue, 20 Apr 2021 02:38:49 +0000 (22:38 -0400)] 
lttng-ctl: separate support of named/unnamed trigger registration

Signed-off-by: Jérémie Galarneau <>
Change-Id: I37e78344dd14d00c617cd462914dee287e3b24bb

21 months agosessiond: add support for anonymous triggers
Jérémie Galarneau [Tue, 20 Apr 2021 04:43:22 +0000 (00:43 -0400)] 
sessiond: add support for anonymous triggers

Signed-off-by: Jérémie Galarneau <>
Change-Id: I5b7fb29700af7ac7b633e5d73fb29f99f55ebfe8

21 months agoFix: lttng-ctl: assertion failure during unregistration of trigger
Jérémie Galarneau [Tue, 20 Apr 2021 16:48:05 +0000 (12:48 -0400)] 
Fix: lttng-ctl: assertion failure during unregistration of trigger

Issue observed

lt-trigger_name: trigger.c:302: int lttng_trigger_serialize(const struct lttng_trigger *, struct lttng_payload *): Assertion `(creds->uid).is_set' failed.

Program terminated with signal SIGABRT, Aborted.
 #0  0x00007fb74129eef5 in raise () from /usr/lib/
 #1  0x00007fb741288862 in abort () from /usr/lib/
 #2  0x00007fb741288747 in __assert_fail_base.cold () from /usr/lib/
 #3  0x00007fb741297646 in __assert_fail () from /usr/lib/
 #4  0x00007fb74169bab7 in lttng_trigger_serialize (trigger=0x5616f6f70060, payload=0x7ffe5819d140) at trigger.c:302
 #5  0x00007fb74169cef0 in lttng_trigger_copy (trigger=0x5616f6f70060) at trigger.c:859
 #6  0x00007fb74164302e in lttng_unregister_trigger (trigger=0x5616f6f70060) at lttng-ctl.c:3350
 #7  0x00005616f50c675f in register_named_trigger () at trigger_name.c:295
 #8  0x00005616f50c6879 in main (argc=1, argv=0x7ffe581a07d8) at trigger_name.c:343


When creating a trigger instance and using it to unregister an existing
trigger, its credentials are unset (meaning 'default'). Expecting this,
lttng_unregister_trigger() copies the source trigger to change its
credentials to those of the caller.

Unfortunately, the trigger copy operation expects credentials to be set.

We don't run into this situation typically since the trigger instance
used to perform the unregistration is sourced from a listing or is the
same instance that was used to perform the registration (which sets the
credentials before serializing).


A proper implementation of "copy" is provided for the trigger object
itself. For its condition and action, we still use the same "trick"
of leveraging the serdes code to perform a deep-copy, keeping the change


None really, except that we lose some of the code sharing between
copy and serdes.

Signed-off-by: Jérémie Galarneau <>
Change-Id: I71b7b075c959bc4935621543c4d379f62b7dabdf

21 months agoRename group action files to list files
Jonathan Rajotte [Tue, 20 Apr 2021 02:06:33 +0000 (22:06 -0400)] 
Rename group action files to list files

Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Iea4c2fe0a2d7001e8c05b4bb33c24e5641b193b0

21 months agoRename action group to action list
Jonathan Rajotte [Tue, 20 Apr 2021 01:57:13 +0000 (21:57 -0400)] 
Rename action group to action list

This is necessary to convey that the `group` an ordered sequence of
actions. We use the term `list` to put an emphasis on the ordered nature
of the group.

Files rename follows.

Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Idb85d8ca5b60947d8dc3d43d98c8d915bf34c3f2

21 months agoRename on-event to event-rule-matches
Jonathan Rajotte [Tue, 20 Apr 2021 01:22:09 +0000 (21:22 -0400)] 
Rename on-event to event-rule-matches

Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Icb596abdd0c291643f144ce274919b4094828e95

21 months agoMove on-event*.* to event-rule-matches*.*
Jonathan Rajotte [Tue, 20 Apr 2021 01:03:40 +0000 (21:03 -0400)] 
Move on-event*.* to event-rule-matches*.*

Code renaming follows.

Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ifb2de118546d39877e77ba30ba8720f75240eb39

21 months agoIntroduce emission site for syscall event rule
Jonathan Rajotte [Fri, 16 Apr 2021 21:24:20 +0000 (17:24 -0400)] 
Introduce emission site for syscall event rule

The tracer support multiple emission site configuration: entry, exit,

On the CLI, the emission site is exposed directly on the event rule type
with the following syntax:


`--type=syscall` is equivalent to `--type=syscall:entry+exit`.

Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I65faea6872f121b98b781d931b6cc7301f20a0b6

21 months agolttng list-triggers: handle all condition types
Simon Marchi [Thu, 15 Apr 2021 13:07:31 +0000 (09:07 -0400)] 
lttng list-triggers: handle all condition types

At the moment, only the event-rule-matches condition is handled by the
list-triggers commands. Change it to handle all existing condition

Because these other condition types can't be created using the
command-line interface, add a util program that creates and registers
triggers for the purpose of the test. The test triggers with the
event-rule-matches condition are kept as is, created using the
command-line interface.

Change-Id: I6a2b0442800c93f7e8815dce96d1cf1928d5725a
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agoFix: sessiond: trigger with condition not requiring event notifier cannot be listed
Jonathan Rajotte [Mon, 19 Apr 2021 18:04:53 +0000 (14:04 -0400)] 
Fix: sessiond: trigger with condition not requiring event notifier cannot be listed

Observed issue

The lttng-sessiond process aborts when an lttng error query is performed
against a trigger that uses a condition other than "event-match".


which does not have a "domain type".

This results in the call to `abort()` in
`event_notifier_error_accounting_get_count` of the default case.


Check if the trigger "needs" or at least "depends" on tracer notifier.

Known drawbacks


Signed-off-by: Jonathan Rajotte <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I3d5f09617f95315060a611b464d1df95cb80c5bd

21 months agolttng add-trigger: remove support for conditions other than event-rule-matches
Simon Marchi [Thu, 15 Apr 2021 11:49:16 +0000 (07:49 -0400)] 
lttng add-trigger: remove support for conditions other than event-rule-matches

We initially only want to support the event-rule-matches condition, so
remove any trace of the other ones. They'll be added later as needed.

Change-Id: I66b79bea89257187865ebf599ef0341279629ec6
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agolttng {add,list,remove}-trigger: rename user id to owner uid
Simon Marchi [Thu, 15 Apr 2021 11:31:01 +0000 (07:31 -0400)] 
lttng {add,list,remove}-trigger: rename user id to owner uid

Implement the proposal to rename the --user-id option to --owner-uid in
the add-trigger and remove-trigger commands.  Update the output of
list-triggers as well.

Change-Id: I79977a0efe80d96917fcaf55909a78c81047c388
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agolttng add-trigger: replace log level options with --log-level
Simon Marchi [Thu, 15 Apr 2021 02:28:07 +0000 (22:28 -0400)] 
lttng add-trigger: replace log level options with --log-level

Implement the proposal to replace the --loglevel and --loglevel-only
options with a single --log-level option.

The syntax of the argument to --log-level is:

 - `LEVEL`: to specify only this level
 - `LEVEL..`: to specify from this level up to the most critical level
 - `..`: to specify any level. Basically the same as no `--log-level`

The intent is to keep the door open to fully support ranges with the
`LEVEL1..LEVEL2` syntax.  The loglevel_parse_range_string function and
friends are implement this, but their caller in add_trigger.c,
parse_log_level_string, artificially restricts it to the two cases
shown above.

Change-Id: Id8607b3dae2db5aace263f0c56ada2e822db907c
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agolttng add-trigger: replace event rule type options with --type
Simon Marchi [Wed, 14 Apr 2021 02:21:56 +0000 (22:21 -0400)] 
lttng add-trigger: replace event rule type options with --type

Implement the proposal to replace the --function, --probe,
--userspace-probe, --syscall and --tracepoint options, used to select an
event rule type, with a single --type option.

The --probe, --userspace-probe and --function options used to take an
argument, the name of the location.  For these types, the --location
option is introduced to specify that information.

Change-Id: Ib62e502beb6832a3d26cb135ca6b2746382f2075
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agolttng add-trigger: replace domain options with single --domain
Simon Marchi [Tue, 13 Apr 2021 14:32:21 +0000 (10:32 -0400)] 
lttng add-trigger: replace domain options with single --domain

Implement the proposal to replace the --userspace, --kernel, --log4j,
--jul and --python options, used to select a domain, with a single
--domain option that takes an argument.

Change-Id: I9c5ff77523bb974bc1facb6732f3122c2e30395e
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agolttng add-trigger: some updates to event rule to new syntax
Simon Marchi [Mon, 12 Apr 2021 16:25:50 +0000 (12:25 -0400)] 
lttng add-trigger: some updates to event rule to new syntax

Implement a few of the proposals for the event rule syntax related to
event names that we want to adopt for the add-trigger command.

 - Remove the positional argument (tracepoint name).
 - Add --name option for tracepoints, syscalls and loggers.
 - Add --event-name option for probes.
 - Rename --exclude to --exclude-names.
 - Remove the --all/-a option.  The equivalent now is to omit
   --name, which is the equivalent of --name=*.

Change-Id: I7161570a47716c458a60d679bc229a8c8843b04f
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agolttng add-trigger: rename on-event condition to event-rule-matches
Simon Marchi [Thu, 15 Apr 2021 01:33:46 +0000 (21:33 -0400)] 
lttng add-trigger: rename on-event condition to event-rule-matches

Implement the proposal to rename the on-event condition to
event-rule-matches. This patch only updates the CLI, the API will be
renamed later.

Change-Id: I341d11922998043414028477fb65cfbb5a2d66cd
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agolttng {add,list}-triggers: use `name` instead of `id`
Simon Marchi [Fri, 9 Apr 2021 18:46:42 +0000 (14:46 -0400)] 
lttng {add,list}-triggers: use `name` instead of `id`

The right term is "trigger name", not "trigger id".  Change the option
to add-trigger accordingly, as well as the output of list-trigger.

Change-Id: I5c304aea2c37f983de001cb11c5ba8859f564617
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agolttng add-trigger: parse condition / action name as option arguments
Simon Marchi [Fri, 9 Apr 2021 17:14:44 +0000 (13:14 -0400)] 
lttng add-trigger: parse condition / action name as option arguments

Change the `add-trigger` command's --condition and --action options to
take the condition name and action name as option arguments.  Currently,
when we see the --condition option, we go into the parse_condition
function and expect the first argument to be the condition name (same
idea for the action).  Since the condition/action name is mandatory
after --condition/--action, it is simpler to say that --condition and
--action require an argument.

This will let the user do:


in addition to the current syntax:

    --condition on-event

The code is a bit cleaner as a result.

Change-Id: Ic7ea97c2657e5de6ae18563694ad22bbffbb2aa8
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agoAdd .editorconfig file
Simon Marchi [Wed, 14 Apr 2021 18:49:54 +0000 (14:49 -0400)] 
Add .editorconfig file

Many editors support reading this file to automatically configure indent
/ whitespace settings. The author of this patch would be extremely
grateful if the maintainer of the project would consider merging the
patch in the master branch of the project's repository.

Change-Id: I84ae62fe3e028d0d40421943b3a53207854efed7
Signed-off-by: Simon Marchi <>
Signed-off-by: Jérémie Galarneau <>
21 months agoAllow users to create trigger with their uid
Francis Deslauriers [Thu, 15 Apr 2021 19:46:18 +0000 (15:46 -0400)] 
Allow users to create trigger with their uid

Currently, the `add-trigger` prints the following if a user uses the
`--user-id` with its own uid:
  Error: Failed to set trigger's user identity.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ie0a642b3faf2259a892def3cb19a899e61cb4705

21 months agolttng: list-triggers: implement listing of SDT userspace-probe
Francis Deslauriers [Wed, 14 Apr 2021 21:25:27 +0000 (17:25 -0400)] 
lttng: list-triggers: implement listing of SDT userspace-probe

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Id57c265dcdb3b324ffbb274ca97ead9364275cf0

21 months agoTests: cleanup: rework trigger listing tests
Francis Deslauriers [Thu, 15 Apr 2021 13:16:38 +0000 (09:16 -0400)] 
Tests: cleanup: rework trigger listing tests

- Rename `list_triggers()` -> `list_triggers_matches_ok()` to make it
  obvious it's testing something,
- Add `diag` to all test cases,
- Launch only one lttng-sessiond for all test cases to reduce test
  runtime, and
- remove-trigger all triggers at the end of every test cases.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Icbbd08f521565ef1cae901bb192cf6f8f1cdb7ea

21 months agoTests: event-notifier: multi UID error accounting support
Francis Deslauriers [Wed, 14 Apr 2021 17:09:15 +0000 (13:09 -0400)] 
Tests: event-notifier: multi UID error accounting support

The new test case adds one root trigger and one regular user trigger as
well as apps from both of these users.

The test then confirm that the error accounting of the root trigger
reports what is happening on the regular user's app as well as its own

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Iaec231863de98b14891602bdae010449989de6f9

21 months agoFix: tests: quote variable in case it's not set
Francis Deslauriers [Mon, 19 Apr 2021 18:58:31 +0000 (14:58 -0400)] 
Fix: tests: quote variable in case it's not set

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ib0751699eb9deb02f47739062c99dbb8535c3163

21 months agoust: error accounting: don't print error messages if app is dead
Francis Deslauriers [Wed, 21 Apr 2021 20:04:25 +0000 (16:04 -0400)] 
ust: error accounting: don't print error messages if app is dead

UST applications may exit during the registering process. It's not an
error and should be expected.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I90f91252849ba362e73dad6c30b9cfdc0185abe4

21 months agosessiond: split event notifier error counter CLI options
Francis Deslauriers [Mon, 12 Apr 2021 15:39:08 +0000 (11:39 -0400)] 
sessiond: split event notifier error counter CLI options

With this commit, users can specify the size of event notifier error
counting buffers for each domain independently using the following new
lttng-sessiond options:

The index allocation is now also per-domain meaning that index
allocation in the kernel domain doesn't affect available indices in the
userspace domain and reversely.

Small changes:
- Add manual page description of the new options,
- Rename `struct error_account_entry` to
  `struct ust_error_accounting_entry`.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I4758d32c00cb432be377fd67eaffa11b193bad74

21 months agoClean-up: sessiond: error-query: remove unneeded goto
Jérémie Galarneau [Wed, 21 Apr 2021 19:39:09 +0000 (15:39 -0400)] 
Clean-up: sessiond: error-query: remove unneeded goto

Signed-off-by: Jérémie Galarneau <>
Change-Id: Ie0d02a5151b359ffb1e9ce487811d8235c4a3d9d

21 months agoFix: sessiond: action-executor: uninitialized session_name used in logging
Jérémie Galarneau [Wed, 21 Apr 2021 19:36:04 +0000 (15:36 -0400)] 
Fix: sessiond: action-executor: uninitialized session_name used in logging

CID 1452636 (#1 of 1): Uninitialized pointer read (UNINIT)
8. uninit_use_in_call: Using uninitialized value session_name when
calling fprintf

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <>
Change-Id: I497c613e8cb1342948b726cc5c196e46d61d83dd

21 months agoClean-up: lttng: add-trigger: silence coverity warning
Jérémie Galarneau [Wed, 21 Apr 2021 19:31:38 +0000 (15:31 -0400)] 
Clean-up: lttng: add-trigger: silence coverity warning

CID 1452634 (#1 of 1): Resource leak (RESOURCE_LEAK)
23. leaked_storage: Variable error going out of scope leaks the storage
it points to.

The code path shown by Coverity does not appear reachable, but this
fixes the warning nonetheless.

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <>
Change-Id: I9682616b123de108c5717cee2c17349212f224d5

21 months agoFix: error-query: leak of trigger on malformed error-query comm buffer
Jérémie Galarneau [Wed, 21 Apr 2021 19:28:31 +0000 (15:28 -0400)] 
Fix: error-query: leak of trigger on malformed error-query comm buffer

CID 1452633 (#1 of 1): Resource leak (RESOURCE_LEAK)
10. leaked_storage: Variable trigger going out of scope leaks the
storage it points to

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ic3ab0c41b6667fb875992e545fcba046edc071fc

21 months agoFix: error-query: leak of trigger on allocation error
Jérémie Galarneau [Wed, 21 Apr 2021 18:39:52 +0000 (14:39 -0400)] 
Fix: error-query: leak of trigger on allocation error

1452630 Resource leak

The system resource will not be reclaimed and reused, reducing the
future availability of the resource.

In lttng_error_query_action_create: Leak of memory or pointers to system
resources (CWE-404)

CID 1452630 (#1 of 1): Resource leak (RESOURCE_LEAK)
21. leaked_storage: Variable trigger_copy going out of scope leaks the
storage it points to.

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <>
Change-Id: I4dd99390f1fd5ad957ab6500971dd2ed67a1c722

21 months agoClean-up: tests: notification-client: unused assignment
Jérémie Galarneau [Wed, 21 Apr 2021 18:34:46 +0000 (14:34 -0400)] 
Clean-up: tests: notification-client: unused assignment

1452629 Unused value

An assigned value that is never used may represent unnecessary
computation, an incorrect algorithm, or possibly the need for cleanup or

In main: A value assigned to a variable is never used. (CWE-563)

CID 1452629 (#1 of 1): Unused value (UNUSED_VALUE)assigned_value:
Assigning value -1 to ret here, but that stored value is overwritten
before it can be used

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <>
Change-Id: I0d80a244a7b2b3d6aed57d58ca5435230d664f99

21 months agoFix: relayd: leak of config_path on duplicate --config option
Jérémie Galarneau [Wed, 21 Apr 2021 18:30:02 +0000 (14:30 -0400)] 
Fix: relayd: leak of config_path on duplicate --config option

1452207 Resource leak

The system resource will not be reclaimed and reused, reducing the
future availability of the resource.

In lttng_notification_create_from_payload: Leak of memory or pointers to
system resources (CWE-404)

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ib4f6b388f4ff24eedcbff64570bd9fa10a445304

21 months agoFix: lttng-ctl: trigger leak on failure to deserialize evaluation
Jérémie Galarneau [Wed, 21 Apr 2021 18:22:08 +0000 (14:22 -0400)] 
Fix: lttng-ctl: trigger leak on failure to deserialize evaluation

1452207 Resource leak

The system resource will not be reclaimed and reused, reducing the
future availability of the resource.

In lttng_notification_create_from_payload: Leak of memory or pointers to
system resources (CWE-404)

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <>
Change-Id: I5a66af837d46ca4b8e1909012cd28dc8ea990bad

21 months agoFix: tests: discarded notifications: missing `list-triggers` call
Francis Deslauriers [Tue, 20 Apr 2021 13:52:00 +0000 (09:52 -0400)] 
Fix: tests: discarded notifications: missing `list-triggers` call

I get the following test failure when running the
test_notification_notifier_discarded_count test case.

  # Kernel event notifer error counter
  ok 1 - Add trigger my_trigger
  ok 2 - No discarded tracer notification message
  ok 3 - Trigger 'errors: none' notification message
  ok 4 - Tracer notification discarded line printed
  ok 5 - Discarded tracer notification number non-zero as expected
  ok 6 - Remove trigger my_trigger
  ok 7 - No `on-event` kernel notifier enabled as expected
  ok 8 - Add trigger my_trigger
  ok 9 - No discarded tracer notification message
  not ok 10 - Trigger 'errors: none' notification message
   #   Failed test 'Trigger 'errors: none' notification message'
   #   in tests/regression/tools/notification/test_notification_notifier_discarded_count:test_kernel_notifier_discarded_count() at line 108.
  ok 11 - Remove trigger my_trigger

This happens because we test the `list-triggers` output on outdated
content. We need to call `list-triggers` right before testing the output
of it.

In this commit, I also changed the number of iteration to 2000 as it's
sufficient to generate discarded notifications.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I66d54f9178f9f37ff2fd899278e77fe50e455c10

21 months agoTests: fix: notifier discarded count: typo results in failure
Jérémie Galarneau [Tue, 20 Apr 2021 05:01:47 +0000 (01:01 -0400)] 
Tests: fix: notifier discarded count: typo results in failure

Signed-off-by: Jérémie Galarneau <>
Change-Id: I94b8c60764e1a0d79b25fd252c1a344d807fa61f

21 months agoCleanup: tests: test_userspace_probe: remove extra whitespaces
Francis Deslauriers [Wed, 14 Apr 2021 21:30:13 +0000 (17:30 -0400)] 
Cleanup: tests: test_userspace_probe: remove extra whitespaces

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I6e890a6c1927feb4a09f46b200294cb2faf8a580

21 months agoCleanup: add `lttng_ht_type_str()`
Francis Deslauriers [Wed, 20 Jan 2021 21:18:09 +0000 (16:18 -0500)] 
Cleanup: add `lttng_ht_type_str()`

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I1f7d9ae029f11a454cbda6b05eb22457d6b0be74

21 months agoFix: lttng-ctl: appending to dynamic buffer invalidates its data member
Francis Deslauriers [Thu, 15 Apr 2021 01:19:41 +0000 (21:19 -0400)] 
Fix: lttng-ctl: appending to dynamic buffer invalidates its data member

The following commands fail:
  lttng add-trigger --id T0 --condition on-event -u some-event --action snapshot-session ze-session3 --path /some/path
  lttng remove-trigger T0

  Error: Attempt to create buffer view from another view with invalid length (length > space left after offset in source): source size = 0, offset in source = 0, length = 25
  Error: Invalid trigger received as part of command payload

Valgrind complains in the following way:

==706109== Invalid write of size 4
==706109==    at 0x489FED7: lttng_unregister_trigger (lttng-ctl.c:3281)
==706109==    by 0x43C175: cmd_remove_trigger (remove_trigger.c:171)
==706109==    by 0x43F56B: handle_command (lttng.c:237)
==706109==    by 0x43E9B1: parse_args (lttng.c:421)
==706109==    by 0x43E158: main (lttng.c:470)
==706109==  Address 0x73d8d20 is 4,688 bytes inside a block of size 16,384 free'd
==706109==    at 0x483DFAF: realloc (in /usr/lib/x86_64-linux-gnu/valgrind/
==706109==    by 0x48C1478: lttng_dynamic_buffer_set_capacity (dynamic-buffer.c:166)
==706109==    by 0x48C138C: lttng_dynamic_buffer_append (dynamic-buffer.c:55)
==706109==    by 0x48E3325: lttng_snapshot_output_serialize (snapshot.c:120)
==706109==    by 0x48B46C3: lttng_action_snapshot_session_serialize (snapshot-session.c:173)
==706109==    by 0x48B1FB2: lttng_action_serialize (action.c:130)
==706109==    by 0x48B2DFE: lttng_action_group_serialize (group.c:165)
==706109==    by 0x48B1FB2: lttng_action_serialize (action.c:130)
==706109==    by 0x48ECE66: lttng_trigger_serialize (trigger.c:372)
==706109==    by 0x489FEA0: lttng_unregister_trigger (lttng-ctl.c:3275)
==706109==    by 0x43C175: cmd_remove_trigger (remove_trigger.c:171)
==706109==    by 0x43F56B: handle_command (lttng.c:237)
==706109==  Block was alloc'd at
==706109==    at 0x483B723: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/
==706109==    by 0x483E017: realloc (in /usr/lib/x86_64-linux-gnu/valgrind/
==706109==    by 0x48C1478: lttng_dynamic_buffer_set_capacity (dynamic-buffer.c:166)
==706109==    by 0x48C138C: lttng_dynamic_buffer_append (dynamic-buffer.c:55)
==706109==    by 0x489FE66: lttng_unregister_trigger (lttng-ctl.c:3263)
==706109==    by 0x43C175: cmd_remove_trigger (remove_trigger.c:171)
==706109==    by 0x43F56B: handle_command (lttng.c:237)
==706109==    by 0x43E9B1: parse_args (lttng.c:421)
==706109==    by 0x43E158: main (lttng.c:470)

`lttng_unregister_trigger` samples the address of the lsm header in the
message payload. However, it does so before calling
`lttng_trigger_serialize()` which may increase the underlying buffer's
size (and cause a realloc()).

Most of the time the message buffer is large enough _or_ its realloc
yields the same address which hid the problem. However, I stumbled on a
case (a trigger which snapshots to a location) where the realloc ends-up
returning a completely different address, causing invalid data to be
sent to the session daemon.

Sample the lsm header address after the serialization of the trigger.

An identical fix was done for the `lttng_register_trigger` function in:
  commit b22f4f54e95ae13edda1d4d5efd1e4845a6319c4
  Author: Jérémie Galarneau <>
  Date:   Thu Feb 18 18:13:19 2021 -0500

      Fix: lttng-ctl: appending to dynamic buffer invalidates its data member

I reuse the bug explanation for this commit message.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: Ic50c96dcada9e0595b0fab1d2f357c183b53e1de

21 months agoFix: ust-app: error counter index never set
Francis Deslauriers [Wed, 14 Apr 2021 14:50:28 +0000 (10:50 -0400)] 
Fix: ust-app: error counter index never set

The `struct ust_app_event_notifier_rule::error_counter_index` field is
currently never set so all error counting is done in bucket index 0.

Set the error counter index.

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I951095dee5586111699b0ea0e3bc26c0fb4a535d

21 months agoFix: lttng: -Wshadow error in cmd_snapshot
Francis Deslauriers [Wed, 14 Apr 2021 14:12:04 +0000 (10:12 -0400)] 
Fix: lttng: -Wshadow error in cmd_snapshot

The optarg variable name shadows a variable in an external dependency.
clang returns the following error on my machine:
  commands/snapshot.c:627:16: error: declaration shadows a variable in the global scope [-Werror,-Wshadow]
                          const char *optarg = poptGetOptArg(pc);
  /usr/include/x86_64-linux-gnu/bits/getopt_core.h:36:14: note: previous declaration is here
  extern char *optarg;

Signed-off-by: Francis Deslauriers <>
Signed-off-by: Jérémie Galarneau <>
Change-Id: I85dd7b0761ebc2c023d84ba869c0551f91f38a17

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