lttng-tools.git
3 years 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 <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I30786985c2389570dd342e55d4faf7c552532f8b

3 years 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 <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ief15fc2b7c92582ea36bf64d185720e48d2c94d5

3 years 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
generated.

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 <jeremie.galarneau@efficios.com>
Change-Id: I906dca7d83ce103c009aa477ae5881145e4aa081

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I7b8991ba994585fd8f2b5c6e02b9be7cf8e7123b

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: Ie9093e4032d2cf0d3c0e9fa0d7eda28467033931

3 years 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

Issue
=====

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
reporting:
  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.

Fix
===

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

Notes
=====

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
process.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie77d44233a770610f8a3f4412b84c0fd70c0812e

3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ifd89ad19a17d96975f712bcd298588f2fc28d04f

3 years 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 <mathieu.desnoyers@efficios.com>
  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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2604ea5902fec3bf574c7a249cb65784685a0ae8

3 years 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:
  `LTTNG_KERNEL_x` -> `LTTNG_KERNEL_ABI_x`
  `RING_BUFFER_x` -> `LTTNG_KERNEL_ABI_RING_BUFFER_x`

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

No behavior change intended.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I0bb0ac6bca56b6740ea2d543a6d1bd618d39b36c

3 years 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 <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I551457856c885098bf0de2388936e97456051f93

3 years 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
element.

Change-Id: Icc05d98d51906636362a67588d7c42b58cf33ded
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 liblttng-ctl.so.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I41e7746a8044e85a7d422f138654de1579bf22f1

3 years 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
traced.

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
disabled.

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

Test
====
Add a test case to exercise this exact scenario.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9660064ac6eb99f2aea8851dc98a94cfc1b810e6

3 years 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.

Cause
=====

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
  unsubscribed-from

- 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
  clients
- 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
puzzling.

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
representations.

Solution
========

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.

Drawbacks
=========

None.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie524e7362626406327f4f56e1dba5c8cf469df31

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I474c92f34604100081676dda484513cc8a950c73

3 years 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 <jeremie.galarneau@efficios.com>
3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I6d388b879bc10f5fd5d869352a90701faa20a378

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: Ia5b01e64a3766adced292be7f7436d742b3308c7

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I8db096acc5ddd06107762a44ebfda8eaf96ba0d4

3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I0b9ff1302ca5a3e8bbdddc8a626890c527dcbd59

3 years 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 <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6144521f3186e33c52d7ac20b64cf3e8f7663a55

3 years 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
patch.

This patch:

* Improves the consistency of the the command descriptions in
  `configure.ac`.

* 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.

  `Makefile.am` 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:

  lttng-add-context(1):
      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.

  lttng-add-trigger(1):
      * 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.

  lttng-create(1):
      * 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.

  lttng-disable-event(1):
      Explain how this command can only find recording event rules
      to disable by instrumentation point type and event name condition.

  lttng-enable-event(1):
      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.

  lttng-remove-trigger(1):
      * Use "name" instead of "ID".
      * Use `--owner-id` instead of `--user-id`.

  lttng-sessiond(8):
      * 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.

  lttng-set-session(1):
      List which commands rely on the current tracing session
      concept.

  lttng(1):
      * 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 <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6b98f4907d94763f3bfcb6576e4add9cfc59a2e3

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: Iba2ccd5d23e90a421386d1ff81cde71fcbbe72fd

3 years 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

use-after-free
==============
The following functions are affected:
  `lttng_event_expr_app_specific_context_field_create()`, and
  `lttng_event_expr_array_field_element_create()`.

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_app_specific_context_field_create()`,
  `lttng_event_expr_array_field_element_create()`, and
  `create_field_event_expr()`.

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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I5fdde462d7345d0dae7ecd2e4f46473a92cd11a9

3 years 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 <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I8920ee21d8202e9b94b95f517c8e1fbe8c9224a0

3 years 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
uninitialized.

Reported-by: scan-build.
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I47286312095ca0f6a889eb0faa93661f92156ec1

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: Ica3763e5e73a9f2796b96c8030c551e730fe63d8

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I3474ba07046c75bc3cfc2c32501d77b3ea880d33

3 years 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.

Cause
=====

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

Solution
========

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
=========

None

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I5ad2c57acc0d03d2814dda59f8ecf2d831fd961e

3 years 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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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
entries.

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
  else:
    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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I74667d30a5b6975bad7975b82f6819e263199cd0

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I9b7379d5f2ed66677666365cf5cf0b98c774f219

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I9afc6730b5462f4bf55e0dba3454efb5b4ca22c9

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I70eff0f4de5ac9b84b699e88232669259eab54db

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: Ifcef490aa15aea8ae4846553fbc63c596583d274

3 years 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: https://review.lttng.org/c/argpar/+/5361

Change-Id: I6fd6271abb7e271704db1e60f680729931a1fbe1
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I10e56e226c7ea3eb6eae6a2ea17f5eae7cff3b6c

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I6831fbe7563d2e1804f10588494d126fbb4202ff

3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib65e4ea8ced397bdd3b30f1401121adbfeeff23a

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I3e479d240c25550f44bbf40944484870da85a401

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I46518b86b34cb13074723b4f2bef38026d898700

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I238e6ca42f65e773e7e88773bc2e4f54b0a78ad5

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: Ib19de93e316640fb9ba37d2df621c3c97cd712f6

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I37e78344dd14d00c617cd462914dee287e3b24bb

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I5b7fb29700af7ac7b633e5d73fb29f99f55ebfe8

3 years 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/libc.so.6
 #1  0x00007fb741288862 in abort () from /usr/lib/libc.so.6
 #2  0x00007fb741288747 in __assert_fail_base.cold () from /usr/lib/libc.so.6
 #3  0x00007fb741297646 in __assert_fail () from /usr/lib/libc.so.6
 #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

Cause
=====

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).

Solution
========

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
small

Drawbacks
=========

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

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I71b7b075c959bc4935621543c4d379f62b7dabdf

3 years 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 <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iea4c2fe0a2d7001e8c05b4bb33c24e5641b193b0

3 years 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 <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Idb85d8ca5b60947d8dc3d43d98c8d915bf34c3f2

3 years 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 <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Icb596abdd0c291643f144ce274919b4094828e95

3 years 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 <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ifb2de118546d39877e77ba30ba8720f75240eb39

3 years 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,
both.

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

 --type=syscall:entry
 --type=syscall:exit
 --type=syscall:entry+exit

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

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I65faea6872f121b98b781d931b6cc7301f20a0b6

3 years 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
types.

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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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".

Cause
=====

The trigger's condition is a LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
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.

Solution
========

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

Known drawbacks
=========

None

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3d5f09617f95315060a611b464d1df95cb80c5bd

3 years 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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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`
         option.

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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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:

    --condition=on-event

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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie0a642b3faf2259a892def3cb19a899e61cb4705

3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id57c265dcdb3b324ffbb274ca97ead9364275cf0

3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Icbbd08f521565ef1cae901bb192cf6f8f1cdb7ea

3 years 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
app.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iaec231863de98b14891602bdae010449989de6f9

3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib0751699eb9deb02f47739062c99dbb8535c3163

3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I90f91252849ba362e73dad6c30b9cfdc0185abe4

3 years 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:
  --event-notifier-error-buffer-size-kernel=
  --event-notifier-error-buffer-size-userspace=

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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4758d32c00cb432be377fd67eaffa11b193bad74

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: Ie0d02a5151b359ffb1e9ce487811d8235c4a3d9d

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I497c613e8cb1342948b726cc5c196e46d61d83dd

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I9682616b123de108c5717cee2c17349212f224d5

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: Ic3ab0c41b6667fb875992e545fcba046edc071fc

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I4dd99390f1fd5ad957ab6500971dd2ed67a1c722

3 years 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
refactoring.

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 <jeremie.galarneau@efficios.com>
Change-Id: I0d80a244a7b2b3d6aed57d58ca5435230d664f99

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: Ib4f6b388f4ff24eedcbff64570bd9fa10a445304

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I5a66af837d46ca4b8e1909012cd28dc8ea990bad

3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I66d54f9178f9f37ff2fd899278e77fe50e455c10

3 years 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 <jeremie.galarneau@efficios.com>
Change-Id: I94b8c60764e1a0d79b25fd252c1a344d807fa61f

3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6e890a6c1927feb4a09f46b200294cb2faf8a580

3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I1f7d9ae029f11a454cbda6b05eb22457d6b0be74

3 years 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

Issue
=====
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==
==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/vgpreload_memcheck-amd64-linux.so)
==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/vgpreload_memcheck-amd64-linux.so)
==706109==    by 0x483E017: realloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==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.

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

Note
====
An identical fix was done for the `lttng_register_trigger` function in:
  commit b22f4f54e95ae13edda1d4d5efd1e4845a6319c4
  Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
  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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic50c96dcada9e0595b0fab1d2f357c183b53e1de

3 years 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

Issue
=====
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.

Fix
===
Set the error counter index.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I951095dee5586111699b0ea0e3bc26c0fb4a535d

3 years 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 <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I85dd7b0761ebc2c023d84ba869c0551f91f38a17

3 years agoFix: python: -Wshadow warning
Francis Deslauriers [Wed, 14 Apr 2021 19:14:45 +0000 (15:14 -0400)] 
Fix: python: -Wshadow warning

Fixes warning when building Python Bindings with SWIG 3.0.12.

  lttng_wrap.c: In function ‘SWIG_Python_NewShadowInstance’:
  lttng_wrap.c:2483:65: warning: declaration of ‘swig_this’ shadows a global declaration [-Wshadow]
   SWIG_Python_NewShadowInstance(SwigPyClientData *data, PyObject *swig_this)
                                                                   ^~~~~~~~~
  lttng_wrap.c:2224:18: note: shadowed declaration is here
   static PyObject *swig_this = NULL;
                    ^~~~~~~~~
  lttng_wrap.c: In function ‘SWIG_Python_SetSwigThis’:
  lttng_wrap.c:2558:51: warning: declaration of ‘swig_this’ shadows a global declaration [-Wshadow]
   SWIG_Python_SetSwigThis(PyObject *inst, PyObject *swig_this)
                                                     ^~~~~~~~~
  lttng_wrap.c:2224:18: note: shadowed declaration is here
   static PyObject *swig_this = NULL;

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Icde5f124e914a158eb190f95e3c012b7f800d7d1

3 years agoFix: kernel consumerd: use of uninitialized variable
Jérémie Galarneau [Mon, 19 Apr 2021 15:07:12 +0000 (11:07 -0400)] 
Fix: kernel consumerd: use of uninitialized variable

‘ret_add_channel’ may be used uninitialized in this function [-Wmaybe-uninitialized]

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I1db71aef9a9585d8737347f8375e688994f56c5f

3 years agoClean-up: sessiond: cmd: abort() on invalid query target
Jérémie Galarneau [Mon, 19 Apr 2021 15:06:23 +0000 (11:06 -0400)] 
Clean-up: sessiond: cmd: abort() on invalid query target

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ia02fb651a18d927c3b04e20bb55aa588d071b87c

3 years agoClean-up: sessiond: cmd: fix bogus -Wmaybe-uninitialized
Jérémie Galarneau [Mon, 19 Apr 2021 15:00:23 +0000 (11:00 -0400)] 
Clean-up: sessiond: cmd: fix bogus -Wmaybe-uninitialized

Old gcc versions report:
cmd.c:4751: ‘query_target_action’ may be used uninitialized in this function [-Wmaybe-uninitialized]

For this to be reachable, a query target would have to change suddenly
during the execution of the function.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id90ca37e232385f73d54558f2a00d01cbf773a92

3 years agoRemove error count property of lttng_condition_on_event
Jérémie Galarneau [Thu, 15 Apr 2021 17:21:14 +0000 (13:21 -0400)] 
Remove error count property of lttng_condition_on_event

Errors related to dropped tracer messages are not reported through
the error query interface.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib5f8bf841f37d98b582209abb44ab8a26c8fbbc6

3 years agolttng: list-triggers: retrieve trigger errors using error queries
Jérémie Galarneau [Thu, 15 Apr 2021 17:14:37 +0000 (13:14 -0400)] 
lttng: list-triggers: retrieve trigger errors using error queries

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I1a80125122e2568491d940c598d8445410bf58d9

3 years agosessiond: implement EXECUTE_ERROR_QUERY command
Jérémie Galarneau [Thu, 15 Apr 2021 17:11:09 +0000 (13:11 -0400)] 
sessiond: implement EXECUTE_ERROR_QUERY command

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3404e85e18b0b4e5d51b620c3a082736d3190066

3 years agolttng-ctl: Add error query interface
Jérémie Galarneau [Thu, 15 Apr 2021 17:09:35 +0000 (13:09 -0400)] 
lttng-ctl: Add error query interface

Change-Id: Ibb0ba800330976aad7b7c501f43a0d23a0dba027
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 years agoadd-trigger: rename --fire-* to --rate-policy=*:value
Jonathan Rajotte [Thu, 15 Apr 2021 21:35:20 +0000 (17:35 -0400)] 
add-trigger: rename --fire-* to --rate-policy=*:value

With the move to firing policy to the action and the renaming to rate
policy, a rename of the CLI options is necessary.

We introduce the following format:

  --rate-policy=<type>:<value>

Where type is either: once-after or every.
Value is an unsigned long long value.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6df264c536293e686033d0baa8fe870c75c28b8d

3 years agoRename firing policy to rate policy
Jonathan Rajotte [Thu, 15 Apr 2021 03:18:25 +0000 (23:18 -0400)] 
Rename firing policy to rate policy

This is necessary since that now that the policy is moved to the actions
it is a bit weird to use the term "firing".

CLI change is done in a later patch.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id6940a49cd0640a8fa7145dab5b805fcfa515f40

3 years agoaction executor: use an execution context to validate enqueued action before execution
Jonathan Rajotte [Tue, 13 Apr 2021 18:49:52 +0000 (14:49 -0400)] 
action executor: use an execution context to validate enqueued action before execution

Problem
======

Let's walk over the following scenario:

Trigger my_trigger:
  condition: ust event a
  action: start session S

At time T, session S exists.

At T + 1, the event A is hit.

At T + 2, the tracer event notification is received and the work item is
queued. Here session S have an id of 1.

At T + 3, the session S is destroyed and a new session S is created,
with a resulting id of 200.

At T +4, the work item is popped from the queue and begin execution and
will start session S with an id of 200 instead of the session S id 1
that was present at the queuing phase.

We effectively want to assign an execution context to an action at the
queuing phase and validate that the execution context is still valid
upon actual execution.

Solution
=====

Instead of iterating over the trigger's actions, we prepare an array of
work sub-item (action_work_subitem) that effectively is a flattened and
augmented array of the trigger's action. For now only the session id is
an action level execution context.

Each action handler is responsible of validating the execution context
before performing the action.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I72fbe8d52d77d1d696fa7d99b662b77e9dad02d5

3 years agotrigger/action executor: move trigger registration state change to client thread
Jonathan Rajotte [Mon, 12 Apr 2021 20:38:16 +0000 (16:38 -0400)] 
trigger/action executor: move trigger registration state change to client thread

Set the unregistered state of the sessiond side trigger object in the
client thread since we want to minimize the possibility of the
notification thread being stalled due to a long execution of an action
in the action executor thread.

Stalling the client thread is, comparatively, less harmful.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I7de875996b430e49ec50896f8b26a75af7993c74

3 years agonotification-thread: add `GET_TRIGGER` command
Francis Deslauriers [Mon, 8 Mar 2021 22:19:51 +0000 (17:19 -0500)] 
notification-thread: add `GET_TRIGGER` command

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ifc94ea894999b9da796aa4fda0d929d237e12d3e

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