lttng-tools.git
15 months agoRevert "Fix: sessiond: erroneous user check logic in session_access_ok"
Jérémie Galarneau [Mon, 17 Aug 2020 20:06:16 +0000 (16:06 -0400)] 
Revert "Fix: sessiond: erroneous user check logic in session_access_ok"

This reverts commit 4064563ea326f6f26d2c458009beb9ebdb3ba840.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ifbcfd0c18631cfca70b2ea85b16824bb26a2a446

15 months agoRevert "sessiond: trigger: run trigger actions through an action executor"
Jérémie Galarneau [Mon, 17 Aug 2020 20:06:14 +0000 (16:06 -0400)] 
Revert "sessiond: trigger: run trigger actions through an action executor"

This reverts commit d1ba29d290281cf72ca3ec7b0222b336c747e925.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I70d57fef86aea94a590720689af751e2554184d0

15 months agoFix: sessiond: erroneous user check logic in session_access_ok
Jérémie Galarneau [Fri, 14 Aug 2020 20:59:18 +0000 (16:59 -0400)] 
Fix: sessiond: erroneous user check logic in session_access_ok

The current session_access_ok logic disallows the access to a session when:
  uid != session->uid && gid != session->gid && uid != 0

This means that any user that is part of the same primary group as the session's
owner can access the session. The primary group is not necessarily (and most
likely) not the `tracing` group.

For instance:
  - the session has uid = 1000, gid = 100
  - the current user has uid = 1001, gid = 100

access to the session is granted.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2e9208286e5508315dae90cb25d34133ca5edcc0

15 months agosessiond: trigger: run trigger actions through an action executor
Jérémie Galarneau [Tue, 11 Feb 2020 04:29:18 +0000 (23:29 -0500)] 
sessiond: trigger: run trigger actions through an action executor

The `action executor` interface allows the notification subsystem to enqueue
work items to execute on behalf of a given trigger. This allows the notification
thread to remain responsive even if the actions to execute are blocking (as
through the use of network communication).

Before this commit, the notification subsystem only handled `notify` actions;
handling code for new action types are added as part of the action executor.

The existing `notify` action is now performed through the action executor so
that all actions can be managed in the same way.

This is less efficient than sending the notifications directly, but could be
optimized trivially (if it ever becomes a problem) when:
  - the action is a group containing only a `notify` action,
  - the action is a `notify` action.

Managing the new action types requires fairly localized changes to the existing
notification subsystem code. The main code paths that are modified are the sites
where `evaluation` objects are created:
  - on an object state change (session or channel state changes, see
    handle_notification_thread_channel_sample and
    handle_notification_thread_command_session_rotation),
  - on registration of a trigger (see
    handle_notification_thread_command_register_trigger),
  - on subscription to a condition (see client_handle_message_subscription).

To understand the lifetime of most objects involved in a work deferral to the
action executor, see the paragraph in notification-thread-internal.h (line 82)
to understand the relation between clients and client lists.

Overview of changes
===

Object state changes

Change-Id: I23290e94d98e781992661f0aee88de9986ed274f
---

As hinted in the notification_client_list documentation, defering work on a
state change is straight-forward: a reference is taken on a client list and the
list is provided to the action executor as part of a work item.

Hence, very little changes are made to the the two state-change handling sites
beyond enqueuing a work item rather than directly sending a notification.

Subscription to a condition
---

A notification client can subscribe to a condition before or after a matching
trigger (same condition and containing a notify action) has been registered.

When a client subscribes to a condition, it is a added to a corresponding
"client list"

Registration of a trigger
---

When a client subscribes to a condition, the current state of
that condition is immediately evaluated. If the condition is true
(for instance, a channel's buffer are filled beyond X% of their
capacity),

TODO:

Change-Id: I7f9bc197715c9ca008a4f1fcd4c86e01b6252dce
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
15 months agoFix: notification: deadlock on cmd_queue.lock and client->lock
Jonathan Rajotte [Tue, 5 May 2020 20:06:58 +0000 (16:06 -0400)] 
Fix: notification: deadlock on cmd_queue.lock and client->lock

Observed issue
==============

Deadlock between the notification thread and the action executor thread.

Thread 5 holds cmd_queue.lock and request the client lock.
Thread 6 holds the client lock and request the cmd_queue lock.

Thread 5 have little value in holding the queue lock considering it effectively to a "pop" of the cmd_queue.

Thread 9 is waiting on the cmd_queue lock but does not hold any other
locks and thus not part of the deadlock but is a casualties of this
deadlock and leave a client "hanging".

Other threads are all in their respective waiting state.

Thread 9 (Thread 0x7f76f2ffd700 (LWP 240467)):
 #0  __lll_lock_wait (futex=futex@entry=0x1ad1308, private=0) at lowlevellock.c:52                                                                                                                                                 [1070/1123]
 #1  0x00007f77052c80a3 in __GI___pthread_mutex_lock (mutex=0x1ad1308) at ../nptl/pthread_mutex_lock.c:80
 #2  0x00000000004611dd in run_command_wait (handle=0x1ad12f0, cmd=0x7f76f2fe31e0) at notification-thread-commands.c:31
 #3  0x000000000046143a in notification_thread_command_unregister_trigger (handle=0x1ad12f0, trigger=0x7f76e4000ef0) at notification-thread-commands.c:148
 #4  0x00000000004444af in cmd_unregister_trigger (cmd_ctx=0x7f76e4000d40, sock=68, notification_thread=0x1ad12f0) at cmd.c:4618
 #5  0x0000000000483d23 in process_client_msg (cmd_ctx=0x7f76e4000d40, sock=0x7f76f2ffcba4, sock_error=0x7f76f2ffcb90) at client.c:2001
 #6  0x000000000047f00b in thread_manage_clients (data=0x1ad1a80) at client.c:2402
 #7  0x000000000047b303 in launch_thread (data=0x1ad1af0) at thread.c:66
 #8  0x00007f77052c5609 in start_thread (arg=<optimized out>) at pthread_create.c:477
 #9  0x00007f77051cc103 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7f7700fcf700 (LWP 240464)):
 #0  __lll_lock_wait (futex=futex@entry=0x1ad1308, private=0) at lowlevellock.c:52
 #1  0x00007f77052c80a3 in __GI___pthread_mutex_lock (mutex=0x1ad1308) at ../nptl/pthread_mutex_lock.c:80
 #2  0x0000000000461bf2 in run_command_no_wait (handle=0x1ad12f0, in_cmd=0x7f7700fce340) at notification-thread-commands.c:87
 #3  0x0000000000461b93 in notification_thread_client_communication_update (handle=0x1ad12f0, id=1, transmission_status=CLIENT_TRANSMISSION_STATUS_QUEUED) at notification-thread-commands.c:400
 #4  0x0000000000497658 in client_handle_transmission_status (client=0x7f76f8004e30, status=CLIENT_TRANSMISSION_STATUS_QUEUED, user_data=0x7f76f8004a00) at action-executor.c:154
 #5  0x0000000000467be7 in notification_client_list_send_evaluation (client_list=0x7f76f8004fe0, condition=0x7f76e40041a0, evaluation=0x7f76cc000cc0, trigger_creds=0x7f76e4004288, source_object_creds=0x0, client_report=0x4971a0 <client_ha
 ndle_transmission_status>, user_data=0x7f76f8004a00) at notification-thread-events.c:4007
 #6  0x00000000004956bb in action_executor_notify_handler (executor=0x7f76f8004a00, work_item=0x7f76f80062d0, action=0x7f76e4004210) at action-executor.c:199
 #7  0x00000000004953fd in action_executor_generic_handler (executor=0x7f76f8004a00, work_item=0x7f76f80062d0, action=0x7f76e4004210) at action-executor.c:493
 #8  0x0000000000495101 in action_work_item_execute (executor=0x7f76f8004a00, work_item=0x7f76f80062d0) at action-executor.c:506
 #9  0x0000000000493ff5 in action_executor_thread (_data=0x7f76f8004a00) at action-executor.c:559
 #10 0x000000000047b303 in launch_thread (data=0x7f76f8004aa0) at thread.c:66
 #11 0x00007f77052c5609 in start_thread (arg=<optimized out>) at pthread_create.c:477
 #12 0x00007f77051cc103 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7f77017d0700 (LWP 240463)):
 #0  __lll_lock_wait (futex=futex@entry=0x7f76f8004e30, private=0) at lowlevellock.c:52
 #1  0x00007f77052c80a3 in __GI___pthread_mutex_lock (mutex=0x7f76f8004e30) at ../nptl/pthread_mutex_lock.c:80
 #2  0x0000000000463080 in handle_notification_thread_command (handle=0x1ad12f0, state=0x7f77017cfb00) at notification-thread-events.c:2936
 #3  0x000000000045e881 in thread_notification (data=0x1ad12f0) at notification-thread.c:705
 #4  0x000000000047b303 in launch_thread (data=0x1ad1420) at thread.c:66
 #5  0x00007f77052c5609 in start_thread (arg=<optimized out>) at pthread_create.c:477
 #6  0x00007f77051cc103 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Cause
=====

The action executor holds the client lock across the communication to
prevent simultaneous update to the client state.

The notification thread holds the cmd_queue lock across operation for no
apparent reason (TODO make sure there is no internal add to the queue. if
so we should reacquire the lock only when necessery.)

Solution
========

Reduce the windows for which the cmd_queue lock is held by the
notification thread to only the "pop" action on the queue. As soon as we
have the lock, get the cmd, remove it from the list and release the
lock. This prevent inverted lock acquisition base on the pattern of the
action executor thread.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I91d30c134bc1a128c96058f0e0cdd325808c91bc

15 months agosessiond: notification: add support for async commands
Jérémie Galarneau [Thu, 13 Feb 2020 21:50:52 +0000 (16:50 -0500)] 
sessiond: notification: add support for async commands

Notification thread commands are currently all blocking. This means
that the emitter of the command uses the notification_thread_command
APIs to (stack) allocate a command context and wait on an lttng_waiter
for a reply.

In preparation for the addition of non-blocking commands, a new type
of asynchroneous commands is introduced. Asynchroneous commands are
"fire-and-forget"; the caller has no way of obtaining the result of
the command.

Asynchroneous command contexts are heap-allocated and their ownership
is transferred to the notification thread. The notification thread
will not attempt to wake-up the emitter and will free() the command
context regardless of the command's result.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6951987dda0262d1500a3b4e1403fb2559a3ff44

15 months agosessiond: notification: refactor: split transmission and poll update
Jérémie Galarneau [Thu, 13 Feb 2020 04:34:08 +0000 (23:34 -0500)] 
sessiond: notification: refactor: split transmission and poll update

Split the notification transmission logic and its effect on a
notification_client from the logic tied to the management of the
notification thread.

This is to make it possible to send (or queue) notifications from the
notification thread or another thread. If another thread encounters an
error or a full socket buffer, a future mechanism will allow it to
signal the notification thread to update its private state (e.g. poll
mask).

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I35d8943cb11473d82b07a4dbc5a0f093cde25a79

15 months agosessiond: notification: synchronize notification client (and list)
Jérémie Galarneau [Tue, 11 Feb 2020 04:06:19 +0000 (23:06 -0500)] 
sessiond: notification: synchronize notification client (and list)

Introduce reference counting to notification_client_list and add
locks to both notification_client and notification_client list.

Of important note, this is in preparation for the introduction of
an action executor thread. The aim of this change is not to make
any part of the notitication sub-system thread-safe in any "general"
sense.

The reference counting and locks are introduced to protect a very
specific usage scenario.

The main thread of the notification subsystem and the action executor
will interact through triggers, evaluations, and client lists.

If the action executor needs to send a notification to a list of
client during the execution of an action group, it obtains the client
list and acquires a reference to it. It then locks the list to iterate
on it, allowing it to send the notification(s) to all subscribed
clients.

Holding the list lock prevents the main thread from disconnecting and
subsequently destroying a client. Holding a reference to the list also
prevents the list from being reclaimed due to a concurent 'unregister
trigger' operation.

No provision for other access scenarios are taken into account.

Squashed fix, otherwise the tests would hang.
Fix: don't hold client lock while handling subscription changes

Holding the client's lock while handling subscription changes causes a
lock inversion between the client list lock and the client lock.

This happens when a client subscribes to a condition that evaluates to
'true' at the time of the subscription. When this happens, a
notification is sent right away and that communication will attempt to
acquire the client lock.

Holding the client lock for such a long period is not needed anyhow
and we can simply protect the communication state when it is actually
modified/used.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I7f38f81fa8bc32e5384538acdffab0824862cff2

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I88a9f66d31e3127b2bcc3f04016c364e0b3fe9ce

15 months agosessiond: notification: introduce the notion of 'active' client
Jérémie Galarneau [Mon, 10 Feb 2020 23:35:27 +0000 (18:35 -0500)] 
sessiond: notification: introduce the notion of 'active' client

Since notification_clients are now accessed from multiple threads, it
is possible for a thread to access a client while it is being
"cleaned-up" following an error.

The 'active' communication flag allows a check to be performed before
any communication is attempted with a client. The communication is
considered 'active' once the handshake has been performed. It is
considered 'inactive' if a fatal protocol error occurs.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: If16f83ef12fe9a6ef597ae464867011811389177

15 months agosessiond: notification: maintain an id to notification_client ht
Jérémie Galarneau [Sat, 8 Feb 2020 04:21:40 +0000 (23:21 -0500)] 
sessiond: notification: maintain an id to notification_client ht

In preparation for the addition of an action execution worker, add a
client_id_ht which will allow the action worker to send commands to
the notification thread referencing clients by 'id' rather than by
their socket.

This is done in order to prevent FD re-use races between the various
threads at play when a communication error occurs on a notification
client socket.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I7b8774c23a4a2a7c41ed8c1652f23d29954a0771

15 months agoFix: tests: `pgrep -f` flags unrelated process as lttng-sessiond
Jonathan Rajotte [Fri, 22 May 2020 14:36:46 +0000 (10:36 -0400)] 
Fix: tests: `pgrep -f` flags unrelated process as lttng-sessiond

Observed issue
==============

lttng-sessiond is not started by start_lttng_sessiond_opt and a vim
process is killed on stop_lttng_sessiond_opt.

Cause
=====
We uses "pgrep -f" with the interested pattern to gather the pids that
should be the lttng processes we are interested in. `pgrep -f` yields
false positives since it matches against the complete cmdline including
parent directory of the command and all arguments.

For example, the following will currently match for the sessiond
pattern:
 vim src/bin/lttng-sessiond/notification-thread-internal.h

This prevents the launch of sessiond by start_lttng_sessiond_opt and end
up killing the vim process on stop_lttng_sessiond_opt.

Solution
========
To alleviate this, we propose a two stage lookup. The first stage uses
"pgrep -f" yielding potential candidates. The second stage performs
grep on the basename of the first field of the /proc/[pid]/cmdline
for each pid candidates.

The first field of /proc/[pid]/cmdline corresponds to the actual command.
We use the basename to ensure that we do not match on the path to the
executable.

Known drawbacks
=========
None

References
==========

https://review.lttng.org/c/lttng-tools/+/3043

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I479ebad27f4965ae16d4442a6fe58ff3157d76fa

15 months agologging: print human-readable thread names when logging
Jérémie Galarneau [Tue, 11 Feb 2020 23:22:13 +0000 (18:22 -0500)] 
logging: print human-readable thread names when logging

The lttng_thread interface used by the session daemon uniquely names
all threads. This name can be used to augment the thread's logging
statement with a human-readable name rather than using the pid/tid
tuple used elsewhere.

Additionally, the thread name is set using the pthread API so that it
is visible in GDB and other tools (e.g. htop).

Invocations of pgrep in the test utilities are replaced by 'pgrep -f',
which matches against the process name.

We are not the first to encounter this problem after renaming the main
thread, see
https://github.com/mongodb/mongo/commit/726cafd713c7333640f8458ec9808ed4f678e3a7#diff-a9003101d1e4a99ac2d43d9b1b839587R122

pgrep uses the name name in /proc/$PID/status which contains the
thread name, not the executable name. In the case of the sessiond,
this is now "Main".

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I73dfe8683b2ea31f7ed0c2ffdfa8332f36e28f9b

15 months agosessiond: clarify the role of notification credentials
Jérémie Galarneau [Tue, 11 Aug 2020 19:58:08 +0000 (15:58 -0400)] 
sessiond: clarify the role of notification credentials

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ica7a7370fcc4d34c9af11bcb9e7435e19b29a6f8

15 months agoUse lttng_trigger credentials to send evaluation to client
Jonathan Rajotte [Tue, 24 Mar 2020 18:08:16 +0000 (14:08 -0400)] 
Use lttng_trigger credentials to send evaluation to client

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I49b4b2aeda09d09b7d8630562660dac96f36b3e7

15 months agotrigger: introduce refcounting
Jonathan Rajotte [Fri, 7 Feb 2020 22:40:46 +0000 (17:40 -0500)] 
trigger: introduce refcounting

Will be used for listing and much more use.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic9ee8753257fcbe15fc1321b18582628328c0154

15 months agotrigger: use condition and action ref counting to ease internal objects management
Jonathan Rajotte [Fri, 7 Aug 2020 20:22:36 +0000 (16:22 -0400)] 
trigger: use condition and action ref counting to ease internal objects management

Currently a trigger object has multiple relationship types with the action and
condition associated to it.

On the API client side, the trigger does not own the action and condition
associated to it. The user is responsible for managing the lifetime of the
associated action and condition object.

On the sessiond side, triggers created from `lttng_trigger_create_from_payload`
currently require that before calling lttng_trigger_destroy, the action and
condition be fetched and deleted using their respective destructor. This
operation cannot be done inside `lttng_trigger_destroy` since the exposed API is
clear that the trigger does no own the objects.

We can facilitate the lifetime/ownership management of the action and condition
objects using their respective reference counting mechanism.

On a trigger creation, the trigger get references on both object. On destroy,
the trigger put the references on the objects.

From an API client perspective, nothing changes. Even better, it prevents
premature freeing of these objects, since the trigger have references to these
objects.

On the sessiond side, we can now move the actual ownership of the action and
condition object to the trigger object. This is done in
`lttng_trigger_create_from_payload` forcing a put of the local references to the
object, effectively moving the ownership to the trigger object.

Note that the `lttng_trigger_get_{action, condition}` do not `get` a reference
to the object before returning it. This is done to comply with the API that was
introduced back in 2.11 which does expect a client to call lttng_{action,
condition}_destroy on the returned object.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I31d196d00c886fcf42c1b16c55e693949373568b

15 months agocondition: introduce reference counting
Jonathan Rajotte [Fri, 7 Aug 2020 19:39:24 +0000 (15:39 -0400)] 
condition: introduce reference counting

This will allows easier management of the trigger ownership of its associated
condition and action objects.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I46420b03bd4bf7948bc2d1f44985edfe86c27c61

15 months agoClean-up: tests: fd-tracker: change spaces to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: tests: fd-tracker: change spaces to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I24fde39587495f5f48f900898755e57c10fbf303

15 months agoClean-up: relayd index: change spaces to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: relayd index: change spaces to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6a79fcdceebc0959bb66525daac288953e863bb3

15 months agoClean-up: sessiond comm relay: change spaces to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond comm relay: change spaces to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2c42c7b7574ccec85524a1b0aed33d108725ad4a

15 months agoClean-up: compat time: change spaces to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: compat time: change spaces to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: If28840c388baffd257e61ef1ecad7c1ea3e3fd68

15 months agoClean-up: kernel consumer: change spaces to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: kernel consumer: change spaces to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I55873fe5500e00d725ebaa241f4054a793b15aee

15 months agoClean-up: sessiond ust-app: change spaces to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond ust-app: change spaces to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4ba505a8206f4ee8838fc3268e3904c496eb3802

15 months agoClean-up: sessiond notification thread: change spaces to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond notification thread: change spaces to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ieabe7e8a2066b30ef8b413896d03f8ff824ddc99

15 months agoClean-up: sessiond kernel: change spaces to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond kernel: change spaces to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3b8f476db2f9038fddf3b648dba0fa06f20db5d8

15 months agoClean-up: sessiond kernel: fix include style
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond kernel: fix include style

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I8959283af0cafa94b0939e0025b08b40ff86653e

15 months agoClean-up: sessiond consumer: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond consumer: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I367ffe89e3930b2e84ad8c70b95bd95a968d974c

15 months agoClean-up: sessiond: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Idb749331397c2b43ea41a33f09bf35d15c4b8f8a

15 months agoClean-up: sessiond manage-consumer: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond manage-consumer: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic897e04aa96bd58c6e8dd340f8537af86c2dd478

15 months agoClean-up: relayd: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: relayd: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4aa7d69ef823e4ea85820cadd23463869f98edf2

15 months agoClean-up: sessiond command: fix include style
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond command: fix include style

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2f3d695a97d31ca5b098872abc566a8b261cdf9c

15 months agoClean-up: sessiond command: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond command: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib809c788f3bf32360cd68b16972636db3ef4dfd7

15 months agoClean-up: relayd trace-chunk: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: relayd trace-chunk: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I789edf8a6b9f893c6e3b5f72fb9001f8e68eebd7

15 months agoClean-up: relayd index: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: relayd index: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9fe8b9fa536a89fd04e989cf8b3f5957de88df1e

15 months agoClean-up: relayd session: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: relayd session: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I545728dc95f67113c0f7adf0cbc9fc742e4018c7

15 months agoClean-up: liblttng-ctl clear: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: liblttng-ctl clear: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I423545aa9de0521b861926b29e21b187500e5fd0

15 months agoClean-up: liblttng-ctl destruction handle: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: liblttng-ctl destruction handle: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie5d8f2fc1e2ad358b287550065f24f8928c8304c

15 months agoClean-up: mi-lttng: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: mi-lttng: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ia6ebea7f227d05cc9ebb8cf84717cfaf59f3e222

15 months agoClean-up: time: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: time: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I922111fab4667a5af35ed45d9bbdee0bcb477b05

15 months agoClean-up: consumer-stream: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: consumer-stream: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Idfe9f1202762bd9a026659d61e50112c81641c88

15 months agoClean-up: consumer metadata cache: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: consumer metadata cache: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9abf075960a33bac01379fdc6fc79dca83f84ee2

15 months agoClean-up: run-as: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: run-as: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Icbf393b779cf66a93b49ecef4279a6db820b4968

15 months agoClean-up: utils: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: utils: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I67341c2a849c340fc56cc03dbca9daaf7c9eddb1

15 months agoClean-up: sessiond rotation: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond rotation: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I8a2192da7b69a5a1945e4605167e7d0c91365681

15 months agoClean-up: sessiond: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: sessiond: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I09854bc28773944ad2b70cb7645dcd53e0ee35ab

15 months agoClean-up: trace-chunk: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: trace-chunk: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I0099bf493c8b80aadf7ac8c7b5668c0bb99d27dd

15 months agoClean-up: consumer: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: consumer: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I688ab6903064cee0ef43b4ee7d395e6a60eb729b

15 months agoClean-up: optional: change space to tabs
Jérémie Galarneau [Tue, 11 Aug 2020 16:22:19 +0000 (12:22 -0400)] 
Clean-up: optional: change space to tabs

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6e08f4cc6198583f3dfd9dd3b02da88244e2aa9d

15 months agotrigger: internal: add credentials information
Jonathan Rajotte [Tue, 24 Mar 2020 16:15:22 +0000 (12:15 -0400)] 
trigger: internal: add credentials information

These credentials are for internal use only. We plan on using them for
listing, run-as filter bytecode generation and more.

Introduce LTTNG_OPTIONAL_GET_PTR which is used to assert and return the
pointer for an LTTNG_OPTIONAL underlying element.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I70d7f79918693b52db9b384b56e6476f3449e71d

15 months agocredentials: implement is_equal
Jonathan Rajotte [Tue, 24 Mar 2020 16:11:41 +0000 (12:11 -0400)] 
credentials: implement is_equal

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I526fd15b8365fd2a77b5aa5250a75d956fd8efc3

15 months agosessiond: clean-up: remove unused `state` function parameter
Jérémie Galarneau [Fri, 7 Feb 2020 23:25:36 +0000 (18:25 -0500)] 
sessiond: clean-up: remove unused `state` function parameter

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id606bc0c0db713902cbab2fafed5c81a05ef5f08

15 months ago.gitignore: add test_unix_socket
Jérémie Galarneau [Mon, 10 Aug 2020 21:41:28 +0000 (17:41 -0400)] 
.gitignore: add test_unix_socket

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic7df31b45ce2ad9806790c1041506ce96e1a9e8d

15 months agosessiond: comm: add fd count information for lttng-ctl -> sessiond comm
Jonathan Rajotte [Tue, 14 Jul 2020 17:00:06 +0000 (13:00 -0400)] 
sessiond: comm: add fd count information for lttng-ctl -> sessiond comm

This allows bulk reception of fds incoming from lttng-ctl before doing
any object deserialization.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I16f054be1d8b8d1e7868784c9b4088750b9a3651

15 months agoTests: add unix socket wrapper unit tests
Jérémie Galarneau [Fri, 7 Aug 2020 02:05:25 +0000 (22:05 -0400)] 
Tests: add unix socket wrapper unit tests

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I0db99d77b47326a5e97c39679a053ba4be7f717c

16 months agopayload-view: mark lttng_payload_view_get_fd_handle_count as const
Jérémie Galarneau [Thu, 6 Aug 2020 19:19:54 +0000 (15:19 -0400)] 
payload-view: mark lttng_payload_view_get_fd_handle_count as const

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I0f0b1620e04fa5a5ae06b096dc940504a7d7553e

16 months agoFix: uprobe: inequality comparison against NULL
Jérémie Galarneau [Wed, 5 Aug 2020 16:09:36 +0000 (12:09 -0400)] 
Fix: uprobe: inequality comparison against NULL

The expression will not have its intended effect.

In lttng_userspace_probe_location_function_serialize: Comparing a
pointer against NULL using an operator such as < or >=.

`binary_fd` is now a fd_handle instance rather than a "raw" fd. All
instances of `binary_fd` are renamed to `binary_fd_handle` to prevent
such errors in the future.

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I57f1a3d5a01029084889a183881fac6f1fe9b6d9

16 months agoFix: action: lttng_action_group_add_action returns status invalid
Jonathan Rajotte [Tue, 7 Jul 2020 23:50:06 +0000 (19:50 -0400)] 
Fix: action: lttng_action_group_add_action returns status invalid

IS_GROUP_ACTION macro was performed on the action to be added instead
of the action representing the group, `group` in this function.

This always resulted in error on call to lttng_action_group_add_action.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iecf133fb2165686d1e8abd2225a8f90df22c41dc

16 months agoFix: evaluation: dereference before NULL check in create_from_payload
Jérémie Galarneau [Tue, 23 Jun 2020 22:06:53 +0000 (18:06 -0400)] 
Fix: evaluation: dereference before NULL check in create_from_payload

An evaluation payload view is created from the view passed to
lttng_evaluation_create_from_payload. Since a view contains a const
copy of the _fds array, it must be initialized as the declaration site.

However, src_view is checked for NULL after the initalization. Coverity
rightfully warns that:

  1429799 Dereference before null check

  There may be a null pointer dereference, or else the comparison against
  null is unnecessary.

  In lttng_evaluation_create_from_payload: All paths that lead to this
  null pointer comparison already dereference the pointer
  earlier (CWE-476)

This is not reachable right now, but it is fixed to silence the warning
and prevent future mistakes.

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3ceace4117ff54265b1f0cf6a4c638aec95f2879

16 months agoTests: rework tracefile_count test to meet the tracefile count limit
Jérémie Galarneau [Thu, 30 Jul 2020 03:13:16 +0000 (23:13 -0400)] 
Tests: rework tracefile_count test to meet the tracefile count limit

The original test simply fires a test application and checks that file
count limits are not exceeded.

The test is reworked to produce events until the total stream size
stabilizes. Then the number of files is checked against the expected
limit.

Some shellcheck warnings are fixed as part of this change.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id9ca3e16c05898c4009b4fb8fcf7882fdcb9dcf1

16 months agoFix: extraneous empty/inactive flush on rotation out of a trace chunk
Jérémie Galarneau [Fri, 31 Jul 2020 15:20:40 +0000 (11:20 -0400)] 
Fix: extraneous empty/inactive flush on rotation out of a trace chunk

Observed issue
==============

A test (tests/regression/tools/tracefile-limits/test_tracefile_count)
occasionally fails on ppc64. The trace validation steps in the fails in
the case where the trace file count limit is set to 1.

Examining the resulting trace shows that the last packet of data
produced by the test application appears to be missing.

The test case enables a channel in "overwrite" mode. Normally, this
would guarantee that the last data produced will always be available in
the resulting trace.

Cause
=====

An empty/inactive flush is performed when rotating "out" of a non-null
trace chunk to ensure that the trace chunk contained at least one
packet.

Looking at the test's resulting trace and by following the consumerd
logs, we see that the test application runs on one CPU for most of its
lifetime. The stream file is repeatedly replaced to make room for the
latest data.

Eventually, the application is migrated to another CPU. A number of
packets are written to this new stream. The session is then stopped
which causes an active flush to occur to close the current packet of
all streams (see `ust_app_stop_trace_all`).

Then, when the session is destroyed, an empty/inactive flush is
performed to ensure that at least one packet was produced in the current
trace chunk [1].

At the moment of writing this empty packet, the consumer daemon sees
that there is not enough space left in the stream file to honour the
trace file size restriction. It thus overwrites the file resulting in
the loss of the last events to replace them with the empty "end of
chunk" packet that occupies a single page.

While the problem is not specific to PowerPC 64, it has a lot more
chances to occur there as pages are typically configured to be of 64kb
length. Due to current implementation limitations, empty packets have
a size of one page.

In other words, 4kb pages typically fit in the space left in the file,
causing the problem to not be easily reproducible on x64.

Note that while the file size limit is specified as "3 * PAGE_SIZE" in
the test, it is rounded-up to 512kb to accomodate at least one
sub-buffer.

Solution
========

[1] This empty/inactive flush is no longer necessary since f96af312b
as an "open packet" (which performs an empty/inactive flush) is
performed when a stream enters a non-null trace chunk. There is no
concern that a trace chunk will be left empty unless this initial flush
fails (see patch comments and work-around).

The empty flush that was performed for data streams is converted
into an active flush under most circumstances; the packet is simply
closed.

Known drawbacks
===============

None.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I5602b7ab8318374f75060489cf9c27af4e058805

16 months agoFix: relayd: double unlock on viewer stream creation error
Jérémie Galarneau [Thu, 30 Jul 2020 16:14:21 +0000 (12:14 -0400)] 
Fix: relayd: double unlock on viewer stream creation error

viewer_stream_create must be called with the relay stream's
lock held since 9edaf114d. A call to pthread_mutex_unlock
was forgotten in the error path of viewer_stream_create resulting
in a double-unlock in some error scenarios.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I613f67440669af52f625b7bdc4e9ae6ce75956ea

16 months agoFix: relayd: live connection fails to open file during clear
Jérémie Galarneau [Tue, 28 Jul 2020 15:29:18 +0000 (11:29 -0400)] 
Fix: relayd: live connection fails to open file during clear

Issue observed
==============

A `session clear` test occasionaly fails on the CI (very rarely, and
more often on PowerPC executors for some reason) with babeltrace
reporting that the live connection was closed by the remote side:

  PASS: tools/clear/test_ust 276 - Waiting for live viewers on url: net://localhost
  07-21 16:17:07.058 23855 23855 E PLUGIN/SRC.CTF.LTTNG-LIVE/VIEWER lttng_live_recv@viewer-connection.c:198 [lttng-live] Remote side has closed connection
  07-21 16:17:07.058 23855 23855 E PLUGIN/SRC.CTF.LTTNG-LIVE/VIEWER lttng_live_session_get_new_streams@viewer-connection.c:1701 [lttng-live] Error receiving get new streams reply
  07-21 16:17:07.058 23855 23855 E PLUGIN/SRC.CTF.LTTNG-LIVE lttng_live_msg_iter_next@lttng-live.c:1665 [lttng-live] Error preparing the next batch of messages: live-iter-status=LTTNG_LIVE_ITERATOR_STATUS_ERROR
  07-21 16:17:07.058 23855 23855 W LIB/MSG-ITER bt_message_iterator_next@iterator.c:864 Component input port message iterator's "next" method failed: iter-addr=0x1014d6a8, iter-upstream-comp-name="lttng-live", iter-upstream-comp-log-level=WARNING, iter-upstream-comp-class-type=SOURCE, iter-upstream-comp-class-name="lttng-live", iter-upstream-comp-class-partial-descr="Connect to an LTTng relay daemon", iter-upstream-port-type=OUTPUT, iter-upstream-port-name="out", status=ERROR
  07-21 16:17:07.059 23855 23855 E PLUGIN/FLT.UTILS.MUXER muxer_upstream_msg_iter_next@muxer.c:454 [muxer] Upstream iterator's next method returned an error: status=ERROR
  07-21 16:17:07.059 23855 23855 E PLUGIN/FLT.UTILS.MUXER validate_muxer_upstream_msg_iters@muxer.c:991 [muxer] Cannot validate muxer's upstream message iterator wrapper: muxer-msg-iter-addr=0x1014d668, muxer-upstream-msg-iter-wrap-addr=0x1014e210
  07-21 16:17:07.059 23855 23855 E PLUGIN/FLT.UTILS.MUXER muxer_msg_iter_next@muxer.c:1415 [muxer] Cannot get next message: comp-addr=0x1014cca8, muxer-comp-addr=0x1015afd8, muxer-msg-iter-addr=0x1014d668, msg-iter-addr=0x1014d598, status=ERROR
  07-21 16:17:07.059 23855 23855 W LIB/MSG-ITER bt_message_iterator_next@iterator.c:864 Component input port message iterator's "next" method failed: iter-addr=0x1014d598, iter-upstream-comp-name="muxer", iter-upstream-comp-log-level=WARNING, iter-upstream-comp-class-type=FILTER, iter-upstream-comp-class-name="muxer", iter-upstream-comp-class-partial-descr="Sort messages from multiple inpu", iter-upstream-port-type=OUTPUT, iter-upstream-port-name="out", status=ERROR
  07-21 16:17:07.059 23855 23855 W LIB/GRAPH consume_graph_sink@graph.c:473 Component's "consume" method failed: status=ERROR, comp-addr=0x1014d128, comp-name="pretty", comp-log-level=WARNING, comp-class-type=SINK, comp-class-name="pretty", comp-class-partial-descr="Pretty-print messages (`text` fo", comp-class-is-frozen=1, comp-class-so-handle-addr=0x10159dd8, comp-class-so-handle-path="/home/jenkins/workspace/lttng-tools_stable-2.12_portbuild/arch/powerpc/babeltrace_version/stable-2.0/build/std/conf/agents/liburcu_version/stable-0.12/test_type/base/deps/build/lib/babeltrace2/plugins/babeltrace-plugin-text.so", comp-input-port-count=1, comp-output-port-count=0
  07-21 16:17:07.059 23855 23855 E CLI cmd_run@babeltrace2.c:2548 Graph failed to complete successfully

  ERROR:    [Babeltrace CLI] (babeltrace2.c:2548)
    Graph failed to complete successfully
  CAUSED BY [libbabeltrace2] (graph.c:473)
    Component's "consume" method failed: status=ERROR, comp-addr=0x1014d128,
    comp-name="pretty", comp-log-level=WARNING, comp-class-type=SINK,
    comp-class-name="pretty", comp-class-partial-descr="Pretty-print messages
    (`text` fo", comp-class-is-frozen=1, comp-class-so-handle-addr=0x10159dd8,
    comp-class-so-handle-path="/home/jenkins/workspace/lttng-tools_stable-2.12_portbuild/arch/powerpc/babeltrace_version/stable-2.0/build/std/conf/agents/liburcu_version/stable-0.12/test_type/base/deps/build/lib/babeltrace2/plugins/babeltrace-plugin-text.so",
    comp-input-port-count=1, comp-output-port-count=0
  CAUSED BY [libbabeltrace2] (iterator.c:864)
    Component input port message iterator's "next" method failed:
    iter-addr=0x1014d598, iter-upstream-comp-name="muxer",
    iter-upstream-comp-log-level=WARNING, iter-upstream-comp-class-type=FILTER,
    iter-upstream-comp-class-name="muxer",
    iter-upstream-comp-class-partial-descr="Sort messages from multiple inpu",
    iter-upstream-port-type=OUTPUT, iter-upstream-port-name="out", status=ERROR
  CAUSED BY [muxer: 'filter.utils.muxer'] (muxer.c:991)
    Cannot validate muxer's upstream message iterator wrapper:
    muxer-msg-iter-addr=0x1014d668, muxer-upstream-msg-iter-wrap-addr=0x1014e210
  CAUSED BY [muxer: 'filter.utils.muxer'] (muxer.c:454)
    Upstream iterator's next method returned an error: status=ERROR
  CAUSED BY [libbabeltrace2] (iterator.c:864)
    Component input port message iterator's "next" method failed:
    iter-addr=0x1014d6a8, iter-upstream-comp-name="lttng-live",
    iter-upstream-comp-log-level=WARNING, iter-upstream-comp-class-type=SOURCE,
    iter-upstream-comp-class-name="lttng-live",
    iter-upstream-comp-class-partial-descr="Connect to an LTTng relay daemon",
    iter-upstream-port-type=OUTPUT, iter-upstream-port-name="out", status=ERROR
  CAUSED BY [lttng-live: 'source.ctf.lttng-live'] (lttng-live.c:1665)
    Error preparing the next batch of messages:
    live-iter-status=LTTNG_LIVE_ITERATOR_STATUS_ERROR
  CAUSED BY [lttng-live: 'source.ctf.lttng-live'] (viewer-connection.c:1701)
    Error receiving get new streams reply
  CAUSED BY [lttng-live: 'source.ctf.lttng-live'] (viewer-connection.c:198)
    Remote side has closed connection
  ok 277 - Clear session J7WXjh7fmMleTCfE
  PASS: tools/clear/test_ust 277 - Clear session J7WXjh7fmMleTCfE
  ok 278 - Clear session J7WXjh7fmMleTCfE
  PASS: tools/clear/test_ust 278 - Clear session J7WXjh7fmMleTCfE
  ok 279 - Stop lttng tracing for session J7WXjh7fmMleTCfE
  PASS: tools/clear/test_ust 279 - Stop lttng tracing for session J7WXjh7fmMleTCfE
  ok 280 - Destroy session J7WXjh7fmMleTCfE
  PASS: tools/clear/test_ust 280 - Destroy session J7WXjh7fmMleTCfE
  # Wait for viewer to exit
  not ok 281 - Babeltrace succeeds

Cause
=====

Looking at the relay daemon logs, it appears that the live client
requests an enumeration of the available streams while a rotation is
ongoing (clear).

Ultimately, this results in the relay daemon attempting to open a
non-existing file:
  PERROR - 16:33:59.242388809 [734380/734387]: Failed to open fs handle to ust/uid/1000/64-bit/chan_0, open() returned: No such file or directory (in fd_tracker_open_fs_handle() at fd-tracker.c:550)

The logs indicate that this file existed at some point. However, it
was unlinked and its newest instance was created in a trace chunk
named "20200727T163359-0400-1".

This chunk name is a temporary name used until the original trace
chunk can be unlinked (cleared) and the newest can be moved in its
place.

The file is being opened as part of the creation of a viewer stream
when make_viewer_stream() fails to find it. This implies that, somehow,
an outdated trace chunk is being used to open the viewer stream's file.

The reason why is that make_viewer_stream is called with the
viewer session's current trace chunk. During a rotation, the use of the
viewer session's current trace chunk is touchy due to the way the
switch-over to a new chunk is handled.

How viewer session/stream trace chunks are rotated
--------------------------------------------------

The viewer polls the relay daemon for new data/metadata to consume using
the `GET_NEXT_INDEX` and `GET_METADATA` commands. Both commands will
indicate to the viewer that it should try again later if a rotation is
ongoing on the "side" of the relay session.

When a rotation is not ongoing, the relay compares the `id` of the
target viewer stream's trace chunk with the relay session's current
trace chunk. If those `id`s don't match, the viewer session's current
trace chunk is then updated to a copy of the relay session's trace
chunk. The viewer stream's files are then closed and re-opened in the
context of the viewer session's now-updated trace chunk.

While the live protocol allows `GET_NEXT_INDEX` and `GET_METADATA` to
communicate to the viewer that it should "retry" later, there is no such
provisions made for the paths that lead to the creation of the viewer
streams. This means viewer streams must be created even if a rotation is
ongoing.

Solution
========

If a rotation is ongoing at the moment of the creation of the viewer
streams, we wish to use a copy of the trace chunk being used by the
relay stream. This way, we can be sure that the streams' files exist.

It is okay for viewer streams to hold references to different copies of
the trace chunks since no user-visible actions are performed when the
reference to those chunks is released. This is different from relay
streams where the detection of the completion of a rotation is done when
the last relay stream releases its reference to a specific trace chunk
instance.

Known drawbacks
===============

None beyond a slight increase (temporary until the next rotation) in the
number of FDs used when a client connects during a session rotation.

Note
====

Since make_viewer_streams now acts on relay and viewer counterparts of
the session and stream objects, the various variables are prefixed with
`relay` and `viewer` to make the code easier to understand.

The locking period of the relay stream is extended to most of the
iteration in make_viewer_stream() rather than only in
viewer_stream_create(). As a result, callers of viewer_stream_create()
must hold the relay stream's lock.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3b9c52a57835134712eadba0f68f6a21e922356b

16 months agoFix: sessiond: unchecked return value
Jonathan Rajotte [Tue, 28 Jul 2020 14:26:02 +0000 (10:26 -0400)] 
Fix: sessiond: unchecked return value

From Coverity:
  CID 1431048 (#1 of 1): Unchecked return value (CHECKED_RETURN)
  1. check_return: Calling lttng_dynamic_buffer_set_size without
     checking return value (as is done elsewhere 32 out of 40 times).

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id15632e3932052cf7dce5d57a08ac6efc84fc92f

16 months agoFix: common: unchecked return value
Jonathan Rajotte [Tue, 28 Jul 2020 14:22:28 +0000 (10:22 -0400)] 
Fix: common: unchecked return value

From Coverity:
  CID 1431050 (#1 of 1): Unchecked return value (CHECKED_RETURN)
  1. check_return: Calling lttng_dynamic_buffer_set_size without
     checking return value (as is done elsewhere 32 out of 40 times).

Solution
========

Since we are inside a the clear operation for the payload, ignore the
return value.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I45c1054de7252aab4b77f330102ff4f489f20a6d

16 months agoFix: common: improper use of negative return
Jonathan Rajotte [Tue, 28 Jul 2020 14:19:30 +0000 (10:19 -0400)] 
Fix: common: improper use of negative return

From Coverity:

  CID 1431053 (#1 of 2): Improper use of negative value (NEGATIVE_RETURNS)
  5. negative_returns: fd_count is passed to a parameter that cannot be
     negative.

Solution
========

Check return value for fd_count and goto error if negative.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ibdb2f065f0ebe51efae9125630a17730386395ac

16 months agoFix: sessiond: unchecked return value
Jonathan Rajotte [Tue, 28 Jul 2020 14:15:04 +0000 (10:15 -0400)] 
Fix: sessiond: unchecked return value

From coverity:

  CID 1431054 (#1 of 1): Unchecked return value (CHECKED_RETURN)
  1. check_return: Calling lttng_dynamic_buffer_set_size without
     checking return value (as is done elsewhere 32 out of 40 times).

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6b5b18d90f194c8081b91b3fbb80dccd29ba19ca

16 months agoFix: relayd: wrong stream type used in DBG statement
Jérémie Galarneau [Mon, 27 Jul 2020 22:14:30 +0000 (18:14 -0400)] 
Fix: relayd: wrong stream type used in DBG statement

get_next_index() is never invoked for metadata streams; the
debug statement was erroneously copy-pasted from the get_metadata()
function.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ia57dac7f102eddc78e24781905b390b4fa54bd80

16 months agosessiond: client: use common payload send fds util
Jérémie Galarneau [Fri, 24 Jul 2020 17:48:00 +0000 (13:48 -0400)] 
sessiond: client: use common payload send fds util

Use lttcomm_send_payload_view_fds_unix_sock instead of an open-coded
version of the same functionality.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I36627423287a059e8b2ab1cc5cb42ca0db53e144

16 months agopayload: use fd_handle instead of raw file descriptors
Jérémie Galarneau [Wed, 22 Jul 2020 20:15:44 +0000 (16:15 -0400)] 
payload: use fd_handle instead of raw file descriptors

Using raw file descriptors with lttng_payloads introduces scary file
descriptor corner-cases when mixing with asynchroneous communication and
lttng_payloads.

Since an lttng_payload doesn't own its file descriptors, attempting it
is easy to fall into a situation where a file descriptor is referenced
by an lttng_payload while the owner is destroyed.

For instance, a userspace probe could be destroyed while its description
is waiting to be sent to a client.

The various use sites of the payload/payload_view APIs are adjusted.

Utilities to send/recv fds through unix sockets using the payload and
payload view interfaces are added as part of this commit as they use
the payload's fd_handles.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I44073f1b683af6c475e8e93c25a76910acf955e4

16 months agoAdd fd_handle interface
Jérémie Galarneau [Wed, 22 Jul 2020 19:29:17 +0000 (15:29 -0400)] 
Add fd_handle interface

An fd_handle allows the reference counting of file descriptors which may
be shared by multiple objects. There is no synchronization imposed (or
provided) for the use of the underlying file descriptors as this utility
meant to be used on file descriptors where this would not make
sense (eventfd, dir fd, etc.)

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I1bdeb48caddda125aa8f41afd502df2eb4a0b8b2

16 months agopayload: don't re-initialize destination payload on copy
Jérémie Galarneau [Wed, 22 Jul 2020 20:43:26 +0000 (16:43 -0400)] 
payload: don't re-initialize destination payload on copy

This makes it possible to re-use the same destination payload
and not always re-allocate memory for its underlying arrays.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I959b2e8851a81034b681d7188c504752620e1b50

16 months agouprobe: transmit binary file descritptor through lttng_payload
Jérémie Galarneau [Fri, 19 Jun 2020 22:44:56 +0000 (18:44 -0400)] 
uprobe: transmit binary file descritptor through lttng_payload

Adapt the userspace probe objects to use the lttng_payload interface.
This streamlines the acquisition of the file descriptors when those
objects are serialized.

File descriptors are transmitted in both directions between liblttng-ctl
and the session daemon making it possible (and safe) to compare
userspace probe instances.

Currently the event listing API does not allow us to express userspace
probe locations that contain a file descriptor. This is an unfortunate
consequence of returning a "flat" array to list events.

Indeed, we can't store a file descriptor in the userspace probe
locations returned to the user in this API since the destructors of the
probe locations are never called. The user simply free()'s the returned
array, which would leak the file descriptors.

The consequence of this is that we can't allow the creation of event
rules using a probe location returned by an lttng_list_events() call.
This is not unsolvable, but I'm not sure if there really is a use-case
for this.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I0f710cbe9deabfd163206fd03618eba183f3d1d2

16 months agoFix: payload view: payload view always refers to parent's position
Jérémie Galarneau [Tue, 23 Jun 2020 04:23:01 +0000 (00:23 -0400)] 
Fix: payload view: payload view always refers to parent's position

A payload view's fd iterator must point to the root view's fd iterator
and not necessarily its parent's. This would cause the iterator
to be reset when views were nested more than two levels deep.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I37eab2ca1437b1a8446449984619106ffff90d3a

16 months agoFix: lttng: leak of userspace probe path on listing
Jérémie Galarneau [Tue, 23 Jun 2020 03:35:02 +0000 (23:35 -0400)] 
Fix: lttng: leak of userspace probe path on listing

realpath() returns a malloc'ed string when `resolved_path` is NULL.
`binary_path` can be safely free'd after it is printed.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic35862f3275f58274ae2572e1d6be736f8a2107e

16 months agopayload: incomplete sentence in lttng_payload_init comment
Jérémie Galarneau [Tue, 23 Jun 2020 03:10:18 +0000 (23:10 -0400)] 
payload: incomplete sentence in lttng_payload_init comment

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic23e7264daa2b55028bfe6298d5c41588bf73919

16 months agocommon: add lttng_payload_view fd count accessor and buffer init
Jérémie Galarneau [Fri, 19 Jun 2020 22:54:58 +0000 (18:54 -0400)] 
common: add lttng_payload_view fd count accessor and buffer init

Allow the initialization of a payload view from a subset of a dynamic
buffer (echoing the lttng_buffer_view API) and add an accessor for the
fd count property.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I647e955b625230010a8789df88f93cf19487ce58

16 months agocommon: move lttng_payload[_view] to libcommon
Jérémie Galarneau [Fri, 19 Jun 2020 22:43:47 +0000 (18:43 -0400)] 
common: move lttng_payload[_view] to libcommon

The payload utils are moved from libsessiond-comm to libcommon since
they present a circular dependancy: a payload uses the dynamic buffer
utilities while the actions, triggers, and conditions make use of the
lttng_payload utilities.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib448bde0e442e7660bb7a61cd629f29442715b21

16 months agocommon: add lttng_dynamic_array_set_count()
Jérémie Galarneau [Fri, 19 Jun 2020 22:20:08 +0000 (18:20 -0400)] 
common: add lttng_dynamic_array_set_count()

Add an lttng_dynamic_array_set_count() helper to resize a dynamic
array.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic38efdb9c2ee6a4176fcde93e4b0d45052d14799

16 months agosessiond: prepare client replies through an lttng_payload
Jérémie Galarneau [Tue, 16 Jun 2020 04:14:13 +0000 (00:14 -0400)] 
sessiond: prepare client replies through an lttng_payload

Modify the command context structure to contain an lttng_payload. This
allows commands to return a payload which contains a file descriptor
without accessing the socket directly.

An interesting side-benefit is that, in practice, this eliminates all
dynamic allocations from the client communications beyond the first
command served. The command context is re-used and the reply buffer is
allocated once and not released (only its size is reset to 0).

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id37b300648db8a9ebec7522e24c70e377c29cddc

16 months agoClean-up: sessiond: change spaces to tab
Jérémie Galarneau [Tue, 16 Jun 2020 03:48:37 +0000 (23:48 -0400)] 
Clean-up: sessiond: change spaces to tab

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iac3eae770fa258f0ff1ea7dddbdc93ac32f4a2dc

16 months agoFix: uprobe: missing error code on allocation failure
Jérémie Galarneau [Mon, 15 Jun 2020 22:44:23 +0000 (18:44 -0400)] 
Fix: uprobe: missing error code on allocation failure

lttng_userspace_probe_location_function_create_from_payload
does not report an allocation failure when strdup fails.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ibed9906cabeca81081647d220a7aef1f54d251d4

16 months agoFix: sessiond: don't negate error code on list error
Jérémie Galarneau [Mon, 15 Jun 2020 22:43:02 +0000 (18:43 -0400)] 
Fix: sessiond: don't negate error code on list error

Listing errors are already negative. Negating in the error path
causes error codes to be interpreted as a number of events and
cause a communication error further on.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6df6fa14e4e443798dfdc1aa7a8fd7cfe380835b

16 months agouserspace-probe: implement is_equal
Jonathan Rajotte [Fri, 31 Jan 2020 21:05:16 +0000 (16:05 -0500)] 
userspace-probe: implement is_equal

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I11ba6c607f5b4b4556dd9048a140a7b0cdda7e4f

16 months agoFix: send/received actual size is overwritten by 'expected' size
Jonathan Rajotte [Thu, 9 Jul 2020 20:22:19 +0000 (16:22 -0400)] 
Fix: send/received actual size is overwritten by 'expected' size

Observed issue
==============

None.

Cause
=====

None.

Solution
========

Return the actual send/received size. Caller code correctly handles
partial send/receive.

Known drawbacks
=========

None

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie52c39d0ab778108e3fde1b2375c0535caec97b1

16 months agounix: add non block send and receive flavors for fd passing
Jonathan Rajotte [Fri, 10 Jul 2020 12:46:04 +0000 (08:46 -0400)] 
unix: add non block send and receive flavors for fd passing

These will be used by the notification subsystem.

It is important to note that based on our current knowledge the sending
/receiving of fds is an all or nothing scenario. The fds are actually
part of the control message instead of the `payload`. On the receiving
side, a reception of N fds will only yield a "read" count of 1 bytes on
reception.

Albeit we don't have to account for the partial send/receive, we have to
manage the EAGAIN/EWOULDBLOCK scenario off non-blocking socket.

The caller of these function must handle the following scenario:

  ret < 0 -> error
  ret == 0 (Nothing received/sent)
  ret > 0 -> success

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iabf8de876991c9f1c5b46ea609f9af961c4a7ab9

16 months agoFix: partial recv lead to client disconnect
Jonathan Rajotte [Thu, 9 Jul 2020 18:57:57 +0000 (14:57 -0400)] 
Fix: partial recv lead to client disconnect

On EWOULDBLOCK and EAGAIN, the ret value from
`lttcomm_send_unix_sock_non_block` and
`lttcomm_recv_unix_sock_non_block` would be equal to -1.

Solution
=====

For such cases, set ret equal to zero since it is effectively what was
received/sent. Caller should treat ret  >= 0 as `success` anyway.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I47677f26850bf544f672d270972de7cc2c6a2817

16 months agotests: return the proper TAP exit code
Michael Jeanson [Mon, 13 Jul 2020 19:41:01 +0000 (15:41 -0400)] 
tests: return the proper TAP exit code

The C TAP library provides the 'exit_status()' function that will return
the proper exit code according to the number of tests that succeeded or
failed.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I0de2349609eb34b1c5e58f09012c1db0126923c0

16 months agoAdd tests/unit/test_payload to .gitignore
Michael Jeanson [Tue, 7 Jul 2020 19:16:19 +0000 (15:16 -0400)] 
Add tests/unit/test_payload to .gitignore

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic792326a78f6eac8d12682dc23642290f14289ff
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
16 months agoTests: live/test_{lttng_,}kernel: use lttng_test_filter_event instead of sched_switch
Francis Deslauriers [Thu, 9 Jul 2020 20:44:32 +0000 (16:44 -0400)] 
Tests: live/test_{lttng_,}kernel: use lttng_test_filter_event instead of sched_switch

Background
==========
These tests currently rely on system load (the `sched_switch` event) to
generate trace data.

Issue
=====
This is can be problematic for the `test_kernel`
test case because it has a fixed sized buffer to store the trace:
  #define mmap_size 524288

This caused this test failure to randomly happen on my machine:
  ok 7 - Get one index per stream
  # mmap_size not big enough
  not ok 8 - Get one data packet for stream 0, offset 0, len 4096
  #     Failed test (live_test.c:main() at line 709)
  [error] Error detaching viewer session
  not ok 9 - Detach viewer session
  #     Failed test (live_test.c:main() at line 715)

Solution
========
Using the `lttng_test_filter_event` event to control the size and
number of the event expected in the trace rather then depending on how
many Electon apps are currently fighting for my CPUs.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I15d500d5becf9c5e526ae11ff0b2a2f4f6b753ac

16 months agoCleanup: Tests: live/test_{lttng_,}ust: testapp not in background
Francis Deslauriers [Thu, 9 Jul 2020 20:30:14 +0000 (16:30 -0400)] 
Cleanup: Tests: live/test_{lttng_,}ust: testapp not in background

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib1f8046acf219f4f070419dc29059d187844976a

16 months agoFix: consumer: Move sanity check within `consumer_subbuffer` functions
Francis Deslauriers [Thu, 9 Jul 2020 21:38:17 +0000 (17:38 -0400)] 
Fix: consumer: Move sanity check within `consumer_subbuffer` functions

The sanity check on the number bytes written by the `consumer_subbuffer`
callback was not correct channel configured in the splice output type in
a live session.

To simplify this, move checks in the callback themselves so they can be
specialized.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4e47a305860684c461ba7ffffd5e3bb3a21990b0

16 months agoCleanup: typo in DBG() statements
Francis Deslauriers [Tue, 7 Jul 2020 16:27:34 +0000 (12:27 -0400)] 
Cleanup: typo in DBG() statements

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I19518292b4e7bd9319cafa05f08c1854f7693168

16 months agoFix: use sys/types.h for ssize_t on Cygwin
Jonathan Rajotte [Tue, 21 Jul 2020 15:00:40 +0000 (11:00 -0400)] 
Fix: use sys/types.h for ssize_t on Cygwin

Observed issue
==============

On cygwin worker:
  In file included from snapshot.c:10:
  ../../src/common/snapshot.h:33:1: error: unknown type name `ssize_t`; did you mean `_ssize_t`?
     33 | ssize_t lttng_snapshot_output_create_from_buffer(
        | ^~~~~~~
        | _ssize_t
  snapshot.c:128:9: error: conflicting types for `lttng_snapshot_output_create_from_buffer`
    128 | ssize_t lttng_snapshot_output_create_from_buffer(
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  In file included from snapshot.c:10:
  ../../src/common/snapshot.h:33:9: note: previous declaration of `lttng_snapshot_output_create_from_buffer` was here
     33 | ssize_t lttng_snapshot_output_create_from_buffer(
        |

Solution
========

Include sys/types.h.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I1df58ffb6df02d6957e1e4eac6ebfb297f3e3bb0

16 months agoAdd kernel and UST time namespace context
Michael Jeanson [Mon, 6 Jul 2020 16:18:01 +0000 (12:18 -0400)] 
Add kernel and UST time namespace context

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I37a67cd61d55e1b94a9f54712143daeabfb47e84

16 months agoFix: sessiond: wrong variable checked for error code
Jérémie Galarneau [Tue, 21 Jul 2020 16:51:48 +0000 (12:51 -0400)] 
Fix: sessiond: wrong variable checked for error code

Coverity reports:
  1430513 Logically dead code

  The indicated dead code may have performed some action; that action
  will never occur.

  In ust_app_open_packets: Code can never be reached because of a
  logical contradiction (CWE-561)

The `open_ret` variable should be checked instead of `ret` after calling
consumer_open_channel_packets.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I49ad2d2b747e29414fee7f0727df1feb343695bb

16 months agoFix: consumerd: double unlock on rotate channel error path
Jérémie Galarneau [Tue, 21 Jul 2020 16:44:59 +0000 (12:44 -0400)] 
Fix: consumerd: double unlock on rotate channel error path

Coverity Scan reports:
  1430541 Double unlock

  May result in undefined behavior.

  In lttng_consumer_rotate_channel: Attempt to release a non-recursive
  lock that is not held (CWE-765)

The error path should jump to end_unlock_channel as the stream
lock is only held for the duration of the call to
consumer_stream_open_packet.

This bug was introduced by the previous commit.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2de684eece963973d0861e5924263575363484f6

16 months agoFix: consumerd: packet sent before channel rotation
Jérémie Galarneau [Mon, 20 Jul 2020 19:29:41 +0000 (15:29 -0400)] 
Fix: consumerd: packet sent before channel rotation

Issue observed
==============

A clear test occasionally fails with the following output:
  # Test ust streaming rotate-clear
  # Parameters: tracing_active=0, clear_twice=1, rotate_before=0, rotate_after=0, buffer_type=uid
  ok 605 - Create session S0BXcJKWrmAwNSzm with uri:net://localhost and opts:
  PASS: tools/clear/test_ust 605 - Create session S0BXcJKWrmAwNSzm with uri:net://localhost and opts:
  ok 606 - Enable channel chan for session S0BXcJKWrmAwNSzm
  PASS: tools/clear/test_ust 606 - Enable channel chan for session S0BXcJKWrmAwNSzm
  ok 607 - Enable ust event tp:tptest for session S0BXcJKWrmAwNSzm
  PASS: tools/clear/test_ust 607 - Enable ust event tp:tptest for session S0BXcJKWrmAwNSzm
  ok 608 - Start tracing for session S0BXcJKWrmAwNSzm
  PASS: tools/clear/test_ust 608 - Start tracing for session S0BXcJKWrmAwNSzm
  ok 609 - Rotate session S0BXcJKWrmAwNSzm
  PASS: tools/clear/test_ust 609 - Rotate session S0BXcJKWrmAwNSzm
  ok 610 - Stop lttng tracing for session S0BXcJKWrmAwNSzm
  PASS: tools/clear/test_ust 610 - Stop lttng tracing for session S0BXcJKWrmAwNSzm
  ok 611 - Clear session S0BXcJKWrmAwNSzm
  PASS: tools/clear/test_ust 611 - Clear session S0BXcJKWrmAwNSzm
  ok 612 - Clear session S0BXcJKWrmAwNSzm
  PASS: tools/clear/test_ust 612 - Clear session S0BXcJKWrmAwNSzm
  Error: Relayd rotate streams replied error 97
  Error: Relayd rotate stream failed. Cleaning up relayd 33
  Error: Relayd send index failed. Cleaning up relayd 33.
  Error: Rotate channel failed
  Error: Stream 76 relayd ID 33 unknown. Can't write index.
  Error: Stream 74 relayd ID 33 unknown. Can't write index.
  Error: Stream 72 relayd ID 33 unknown. Can't write index.
  ok 613 - Start tracing for session S0BXcJKWrmAwNSzm
  PASS: tools/clear/test_ust 613 - Start tracing for session S0BXcJKWrmAwNSzm
  not ok 614 - Stop lttng tracing for session S0BXcJKWrmAwNSzm
  FAIL: tools/clear/test_ust 614 - Stop lttng tracing for session S0BXcJKWrmAwNSzm
  #   Failed test 'Stop lttng tracing for session S0BXcJKWrmAwNSzm'
  #   in ./tools/clear//../../../utils/utils.sh:stop_lttng_tracing_opt() at line 1311.
  ok 615 - Validate trace for event tp:tptest, 1 events
  PASS: tools/clear/test_ust 615 - Validate trace for event tp:tptest, 1 events
  not ok 616 - Read a total of 1 events, expected 4
  FAIL: tools/clear/test_ust 616 - Read a total of 1 events, expected 4
  #   Failed test 'Read a total of 1 events, expected 4'
  #   in ./tools/clear//../../../utils/utils.sh:validate_trace_count() at line 1764.
  Error: Failed to perform an implicit rotation as part of the destruction of session "S0BXcJKWrmAwNSzm": Unknown error code
  not ok 617 - Destroy session S0BXcJKWrmAwNSzm
  FAIL: tools/clear/test_ust 617 - Destroy session S0BXcJKWrmAwNSzm
  #   Failed test 'Destroy session S0BXcJKWrmAwNSzm'
  #   in ./tools/clear//../../../utils/utils.sh:destroy_lttng_session() at line 1347.
  # Test ust streaming clear-rotate

Looking at the relay daemon log when the problem is reproduced,
we see:
  Error: Protocol error: received a packet for a stream that doesn't have a current trace chunk: stream_id = 1, channel_name = chan_0

Cause
=====

The "rotate channel" consumer command iterates over a channel's streams
to perform a rotation and open a new packet when necessary
(see comments).

In the case where a channel is associated with a relay daemon, the
rotation positions are accumulated to send a single "rotate channel
streams" command to the relay daemon. This is done to reduce the time
needed to complete a rotation when tracing to a relay daemon through an
high-latency network connection.

Unfortunately, this causes packets to be opened before the rotation
command was sent to the relay daemon as the "open packet" command
is performed during the iteration on the streams.

Solution
========

Streams for which a packet should be opened are accumulated into an
array of stream pointers. The "open packet" is performed after a
successful rotation of the streams as a second "pass".

Known drawbacks
===============

None.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6cb0b92619da73ebf223e1dfee88530e4244b56b

16 months agoClean-up: relayd: missing space in debug statement
Jérémie Galarneau [Mon, 20 Jul 2020 15:48:23 +0000 (11:48 -0400)] 
Clean-up: relayd: missing space in debug statement

Missing space in rotation debug statement results in logs of the form:
  [...] Rotate stream 1at sequence number 4 [...]

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I7f950224f52164d30f896d0b2bcc59304f842cf1

16 months agoFix: relayd: wrong specifier used in DBG format string
Jérémie Galarneau [Fri, 17 Jul 2020 18:26:17 +0000 (14:26 -0400)] 
Fix: relayd: wrong specifier used in DBG format string

`len` is of type uint64_t while the format string specifies a size of
`%zd`. This results in a warning on most 32-bit architectures.

  In file included from ../../../src/common/common.h:12:0,
                   from live.c:33:
  live.c: In function `viewer_get_metadata`:
  ../../../src/common/error.h:161:35: warning: format `%zd` expects
  argument of type `signed size_t`, but argument 6 has type `uint64_t
  {aka long long unsigned int}` [-Wformat=]
   #define DBG(fmt, args...) _ERRMSG("DEBUG1", PRINT_DBG, fmt, ## args)
                                     ^
  ../../../src/common/error.h:136:51: note: in definition of macro `__lttng_print`
      fprintf((type) == PRINT_MSG ? stdout : stderr, fmt, ## args); \
                                                     ^~~
  ../../../src/common/error.h:161:27: note: in expansion of macro `_ERRMSG`
   #define DBG(fmt, args...) _ERRMSG("DEBUG1", PRINT_DBG, fmt, ## args)
                             ^~~~~~~
  live.c:2051:4: note: in expansion of macro `DBG`
      DBG("Failed to read metadata: requested = %zd, got = %zd",
      ^~~

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I108191e0a94e712b0596d0d52a21cf8c971d6c1e

16 months agoTests: add a "new metadata after clear" test
Jérémie Galarneau [Thu, 16 Jul 2020 21:17:08 +0000 (17:17 -0400)] 
Tests: add a "new metadata after clear" test

Add a test that validates that the relay daemon performs a
metadata stream rotation after a clear.

The test enables a single event and launches a test application to
trigger it 10 times. Once the 10 event occurrences have been seen
by the live client, the session is cleared.

Then, two new events (statedump start and end) are enabled. This causes
new event descriptions to be appended to the metadata stream.

After a clear, the relay daemon should rotate the metadata stream
and send the new contents to the client. The client will then
be able to decode the statedump start/end events.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie6057577e3ee8a7c3ed1a84941308d10d372c16c

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