condition: buffer usage: validation does not check for ratio and bytes threshold

Buffer usage condition do not support having both ratio and bytes
threshold set.

Using `!usage->threshold_ratio.set && !usage->threshold_bytes.set` does
not error out for `threshold_ratio.set == 1` and
`usage->threshold_bytes.set == 1`

0 0 : 1
0 1 : 0
1 0 : 0
1 1 : 0

We want to check for a xnor (`usage->threshold_ratio.set == usage->threshold_bytes.set`)

0 0 : 1
0 1 : 0
1 0 : 0
1 1 : 1

We could also do 2 error check one for not set and one validating that
both are not set.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I5bfcf43bcaf9687ddf9fdebe5ace4f15bda28261

Remove LTTNG_EVENT_RULE_TYPE_KERNEL_FUNCTION

It is not supported for 2.13.

Change-Id: If42b18115cc61da9ee17f281390280b21fdc35a6
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Remove lttng_event_rule_tracepoint

lttng_event_rule_tracepoint is "exploded" in:
   lttng_event_rule_user_tracepoint
   lttng_event_rule_kernel_tracepoint
   lttng_event_rule_jul_logging
   lttng_event_rule_python_logging
   lttng_event_rule_log4j_logging

On the CLI front, the `--domain` option for the add-trigger is removed
since for each event rule type the domain is implicit based on the type.

`--type` accepts the following:
   kernel
   kernel:tracepoint
   kernel:kprobe
   kernel:uprobe
   syscall
     syscall:entry
     syscall:exit
     syscall:entry+exit
     syscall:*
   kernel:syscall
     kernel:syscall:entry
     kernel:syscall:exit
     kernel:syscall:entry+exit
     kernel:syscall:*
   user
   user:tracepoint
   python
   python:logging
   jul
   jul:logging
   log4j
   log4j:logging
   kprobe
   function

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4a0489f8f2a79a2c967f5d69461bed10f40b8278

Test log level for newly introduced event rule type (*_logging, user_tracepoint)

This is in prevision to lttng_event_rule_tracepoint removal.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iff251d7540a16a2a9561d834fc464ac1a6be4f84

Introduce lttng_event_rule_python_logging

A following patch will remove lttng_event_rule_tracepoint.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I222bd4f2616efd1b0c0e36cfe5a89cf5416b6a88

Introduce lttng_event_rule_log4j_logging

A following patch will remove lttng_event_rule_tracepoint.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie94c172ed9550dd7c3ae9967e353a3d6ac5b5907

Introduce lttng_event_rule_jul_logging

A following patch will remove lttng_event_rule_tracepoint.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I95f40920b73b5deb42c2e92ad50c43dba0b0e436

Introduce lttng_event_rule_user_tracepoint

A following patch will remove lttng_event_rule_tracepoint.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: If814c3ba828e4869cde9af4b9d76c8b830f30654

Introduce lttng_event_rule_kernel_tracepoint

A following patch will remove lttng_event_rule_tracepoint.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I614e45be3ef5e41fa081ad24dc1a9dcddb7eb2af

Rename lttng_event_rule_kernel_probe to lttng_event_rule_kernel_kprobe

The add trigger command now accepts `kernel:kprobe` instead of `kernel-
probe`. `kprobe` is still accepted.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ifd6753f337e93ea8eb393b8d686596112292c5bb

Rename lttng_event_rule_userspace_probe to lttng_event_rule_kernel_uprobe

The `--type` option for add trigger now only support `kernel:uprobe`.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2c4de8e314d6fba735343d21c04fff366b92cca9

Rename lttng_event_rule_syscall to lttng_event_rule_kernel_syscall

Allow the usage of "kernel:syscall*" as the `--type` argument for add
trigger. A later patch remove the notion of domain.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib5c87ec937bb0acf9c5133532961dcc31e533884

Rename *emission_site_type to *emission_site

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3027affe23de8674a5a813d18643396e3a1474f1

Rename lttng_event_rule_syscall_(set, get)_pattern to lttng_event_rule_syscall_(set, get)_name_pattern

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ia6d8c55f607cd5af4201a61abaab277994618bb6

Rename *exclusion* to *name_pattern_exclusion*

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic72582dccdc2810dfc07fc66abf776c853d217b6

Rename lttng_event_rule_tracepoint_(set,get)_pattern to lttng_event_rule_tracepoint_(set, get)_name_pattern

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib018d7ab4fab66842302beef19c0971d704d2d02

Build fix: cygwin: unknown type ssize_t

The build fails on cygwin with the following error:

  In file included from actions/path.c:8:
  ../../include/lttng/action/path-internal.h:31:1: error: unknown type name "ssize_t"; did you mean "_ssize_t"?

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I93aac8ef33cfe19b655d80709c9b95a503815bda

Fix: consumer: unbalanced RCU read-side lock on error

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I22ddc8585af84d07e8f3d19e9df582599352a1b8

lttng-enable-event(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6310d753a2fd6db74f4a854a87cda690d3479593

lttng-{enable,disable}-event(1): document default channel limitation

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I0b531be8bde9dfd74bb4a28fe70eeef5eeee7f72

doc/man: log level prefixes are not required

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iddd9eaff96ca857b1249421c31b64bec859429c6

Fix: sessiond: use of uninitialized memory in buffer-usage condition

Issue
=====

valgrind reports the following:
  ==436327== Thread 9 Client manageme:
  ==436327== Syscall param sendmsg(msg.msg_iov[0]) points to uninitialised byte(s)
  ==436327==    at 0x51E418D: __libc_sendmsg (sendmsg.c:28)
  ==436327==    by 0x51E418D: sendmsg (sendmsg.c:25)
  ==436327==    by 0x20D436: lttcomm_send_unix_sock (unix.c:294)
  ==436327==    by 0x186F08: send_unix_sock (client.c:895)
  ==436327==    by 0x18BAFA: thread_manage_clients (client.c:2800)
  ==436327==    by 0x18147D: launch_thread (thread.c:66)
  ==436327==    by 0x51D8608: start_thread (pthread_create.c:477)
  ==436327==    by 0x5314292: clone (clone.S:95)
  ==436327==  Address 0x7540ec1 is 97 bytes inside a block of size 256 alloc'd
  ==436327==    at 0x483DFAF: realloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
  ==436327==    by 0x1E7556: lttng_dynamic_buffer_set_capacity (dynamic-buffer.c:166)
  ==436327==    by 0x1E72FC: lttng_dynamic_buffer_append (dynamic-buffer.c:55)
  ==436327==    by 0x1DE604: lttng_condition_buffer_usage_serialize (buffer-usage.c:123)
  ==436327==    by 0x1DFF47: lttng_condition_serialize (condition.c:98)
  ==436327==    by 0x20ACD0: lttng_trigger_serialize (trigger.c:328)
  ==436327==    by 0x189EBE: process_client_msg (client.c:2258)
  ==436327==    by 0x18B761: thread_manage_clients (client.c:2742)
  ==436327==    by 0x18147D: launch_thread (thread.c:66)
  ==436327==    by 0x51D8608: start_thread (pthread_create.c:477)
  ==436327==    by 0x5314292: clone (clone.S:95)

This can be reproduce by running the sessiond under valgrind and
launching the following binary to register buffer-usage conditions:
  ./tests/regression/tools/trigger/utils/register-some-triggers test_buffer_usage_conditions

The valgrind report is pointing us toward the `struct
lttng_condition_buffer_usage_comm` stack allocation in the
`lttng_condition_buffer_usage_serialize()` function.

The actual issue is that the threshold_bytes/threshold_ratio will not be
initialized in that structure depending on the way the threshold is
expressed.

Fix
===

Make sure the struct is zeroed at the declaration site.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2046f4e0e1d857cfd1a53e0c13aea55f17adada3

lttng-ctl: use lttng_action_path to specify error query actions

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I30a93465231ec963d087b25678b6703a0425ceef

error-query: add lttng_action_path to express the location of an action

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Icc3056029219cc8f0794b06e7021885e193724be

tests: Move tap-driver.sh out of the autotools aux directory

We have made local modifications to this script, move it to the test
suite directory so it doesn't get overwritten by an updated version from
autotools.

Running 'make check' on current RHEL or Fedora without this patch
results in the following error:

  make[5]: Entering directory '/builddir/build/BUILD/lttng-tools-2.12.4/tests/regression'
  tap-driver.sh: invalid option: '--post-script'

Change-Id: I22823176cc5b98901865c9415250ce8e49384cbd
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

lttng-enable-channel(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I26bcfed2b6d71b0bbc2fa89d33f37925c303c91c

lttng-view(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9324b0733ebbaabb824efca4a11330fe3a5c1d0f

lttng-untrack(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ibafe1662e37110962ae3c7fdef9d450b75f2c0a5

lttng-untrack(1): follow the style of lttng-track(1) for the example

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I0c714eb2e504d118cfb3b48bf8e70f33d36d2352

lttng-track(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I21a7906626a09b9964fc51dd083f1c2ea5b855c3

lttng-stop(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6794937457d4f34d649b9edb6a755e091a6af67e

lttng-start(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I893a9e26ac69269150cf0a68ec6968cb5fa9bdbf

lttng-snapshot(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I686f3c8a0e82952a5b673780eef830dea888044d

lttng-save(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I73d4cd169c37d0dbb99ad965d04acc9eaf8a1856

lttng-rotate(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2ee1a32fd44b6abf6a8d58749f1a42731b30ba56

lttng-remove-trigger(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic34f148f061999b90ad47df8efc5c1db2d07f762

lttng-regenerate(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I91074dfc717d481fe16ec4f40533757a0b3f3da4

lttng-load(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I1a4902b1325630c79b8ec121e95874bca1ca8bd6

lttng-list(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id52a51f4daeef2266885d25240699ee921bb041b

lttng-enable-rotation(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I56eafd9e52cd37f48849ddfb82d007c9fb3f3767

lttng-disable-rotation(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I24f132858c12fa4e99b8a24baee9e8becf0d73f8

lttng-disable-event(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I111fbfca2a12517ea6b2f315f4adf0c1b60c37de

lttng-disable-channel(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ia524f1e3f032633670312000f4fc5674c09da498

lttng-destroy(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: If16dcd4197c6af734b1147c9463ae2255b0a1c1f

lttng-create(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2371a84eac9310b6725462ea4278d01497c3e7f4

lttng-clear(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id410c79fddb88de87edda333bec9ef59b6f5afc9

lttng-add-trigger(1): DESCRIPTION: move up the link to "EXAMPLES"

In lttng(1) manual pages, put

    See the <<examples,EXAMPLES>> section below for usage examples.

above references to other manual pages at the bottom of the
"DESCRIPTION" section.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I498a49536d6a876af9a0ed009378d257e483c975

lttng-add-context(1): EXAMPLES: add internal links to relevant options

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I242445993ae85c66074b90078dcd1f8e18cb86db

lttng-disable-event(1): `--tracepoint` option is not the default

I previously thought that not specifying any instrumentation point type
option was equivalent to specifying `--tracepoint`, like with the
`enable-event` command.

It's not the case: `--tracepoint` is just a filter, like `--syscall` and
the others. With `--kernel`, if you don't specify any instrumentation
point type condition option, the `disable-event` command disables
recording event rules regardless of their instrumentation point type.

This patch updates lttng-disable-event(1) to explain this.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I489c5d16dae954f4b5116edce556fdd942c98c4d

Cleanup: tests: name all temporary files to better identify leakage

When using a template, we need to add `--tmpdir` to the `mktemp`
arguments to place the tmp files in `/tmp` or `$TMPDIR`.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id107530578d91700b726ceec016a8cef772e94b0

Cleanup: tests: use find's `-name` option instead of grep

This prevents grep of finding matches in the leading directories listed
by find.

It caused problem when I used the "metadata" string in one of the
directory names:
  /tmp/tmp.test_regen_metadata_ust_trace_path.6FbwPF/

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I7165a3b4e4a16c793fe51c40484978be3a99dbfc

Update version to v2.13.0-rc2

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

Fix: expected procname should not have -ust suffix

commit ("Fix: ustcomm: application name uses the '-ust'-suffixed thread
name") in LTTng-UST removes "-ust" suffix from procname, which appears
in the output trace directory hierarchy.

Adapt tests to not expect this quirk.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I96c3944124bbe154875085a37a51ba2bd458f83b

Fix: Tests: leftover temporary files after tests

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie0c66d45a00e890c1f1e8dc8db7b1baa2cca50f1

Fix: trigger: abort() when adding `--notify` action with python event rule matches

Issue
=====
Adding the following trigger makes the sessiond abort:
  lttng add-trigger --condition=event-rule-matches --domain=python --action=notify

With the following stacktrace:
  (gdb) bt
  #0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
  #1  0x00007ffff7a71859 in __GI_abort () at abort.c:79
  #2  0x00000000004a1eeb in event_notifier_error_accounting_register_event_notifier (trigger=0x7fffe0000f50, error_counter_index=0x7fffefffde38) at event-notifier-error-accounting.c:1075
  #3  0x00000000004743e6 in setup_tracer_notifier (state=0x7fffefffe3e8, trigger=0x7fffe0000f50) at notification-thread-events.c:2606
  #4  0x000000000046dacb in handle_notification_thread_command_register_trigger (state=0x7fffefffe3e8, trigger=0x7fffe0000f50, is_trigger_anonymous=false, cmd_result=0x7fffedfdd6e8) at notification-thread-events.c:2751
  #5  0x000000000046d083 in handle_notification_thread_command (handle=0x601460, state=0x7fffefffe3e8) at notification-thread-events.c:3112
  #6  0x00000000004687bd in thread_notification (data=0x601460) at notification-thread.c:710
  #7  0x0000000000486703 in launch_thread (data=0x601550) at thread.c:66
  #8  0x00007ffff7c47609 in start_thread (arg=<optimized out>) at pthread_create.c:477
  #9  0x00007ffff7b6e293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

This happens because the LTTNG_DOMAIN_PYTHON domain is not handled by
the switch-case.

Fix
===
Add LTTNG_DOMAIN_PYTHON (all other agent domains) as a fallthrough
LTTNG_DOMAIN_UST.

Note
====
Add a basic test case for python agent.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9971cdad8bbc6adca8f6ba49964483c42a25be7d

Tests: move `list_triggers_matches_ok` to utils.sh

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4cd3816fa7cbc1032582b2a99f67a3b14222f972

Tests: Move python test app to `tests/utils/testapp` directory

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9bc55c0fc0b8de42157d64884c7e1ee08b800525

Fix: validate whether event notifiers are supported by UST application

Considering that lttng-sessiond interacts with older (2.12) applications
as well as 2.13+, it needs not to send event notifiers related commands
to an older UST, because the unknown command will cause the protocol to
become out of sync on the communication socket, because the older
lttng-ust does not know how many bytes must be read when receiving the
unknown command. So even though it can return that the command is
unknown, the communication socket becomes out of sync.

Depends-on: lttng-ust: If048c739dd37147ffb2a54715c2101177d2df4f7
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: If9cbc7a7cd6cb957134bf3a2e284ab99ef20e93b

Fix: ust: keep using lttng-ust-sock-8 and lttng-ust-wait-8 filenames

Replicate a change from a lttng-ust header for which there is an
internal copy within lttng-tools for building without lttng-ust.

lttng-ust commit 6a359b8a4006 ("Bump LTTNG_UST_ABI version from 8.1 to
9.0") attempted to ensure that a session daemon linked against an old
lttng-ust-ctl (2.12) would not attempt to interact with newer
applications.

This was done by increasing the major ABI version number, but
introducing LTTNG_UST_ABI_MAJOR_VERSION_OLDEST_COMPATIBLE (set to 8) as
a mean to allow session daemon to accept both major versions 8 and 9.

Unfortunately, changing LTTNG_UST_ABI_MAJOR_VERSION means the filenames
used for communication changed as well, meaning that applications linked
against older lttng-ust 2.12 cannot interact with lttng sessiond linked
against lttng-ust-ctl 2.13, which is unintended.

Therefore, go back to using the previous filenames: lttng-ust-sock-8,
and lttng-ust-wait-8 for communication.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I121c6e5aa13637f13b996dd9e31e06d060b52ca6

Fix: Handle SIGBUS in sessiond and consumerd

There is an issue with the security model of lib ring buffer (lttng-ust)
vs SIGBUS handling by consumer daemon. We do not handle SIGBUS in the
consumer daemon. An application using ftruncate on a ring buffer shm
could cause the consumer to be killed with SIGBUS.

Wire up SIGBUS handling in the session daemon as well given that it also
uses liblttng-ust-ctl.

This depends on "liblttng-ust-ctl: Implement SIGBUS handling" in
lttng-ust, which extends the API of liblttng-ust-ctl, which requires
the user application to define the TLS sigbus state with
DEFINE_LTTNG_UST_SIGBUS_STATE(). It therefore needs to be introduced in
locked-step between lttng-ust and lttng-tools.

Considering that this change in liblttng-ust-ctl modifies the ABI, it is
done with a major soname version bump of the library, so it is allowed
to break the API.

Depends-on: lttng-ust: I7ade988e3e68a87930fbcee3e14e59c3fb66e755

Fixes: #1284
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I76a91616bd35b21c5e891c8306c73ed5e8725ebb

Clean-up: rename double 'lttng' prefixed functions

Rename `lttng_lttng_ust_ctl_flush_buffer` to `lttng_ust_flush_buffer`
since the double prefix is odd, but needed to work-around a clash
with symbols introduced in liblttng-ust-ctl as part of 2.13.

Two functions stubs are not used are removed:
  - lttng_lttng_ust_ctl_get_mmap_read_offset,
  - lttng_lttng_ust_ctl_get_mmap_base.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9a924f503c7d409ed1a28768d07cbbad9d23f503

lttng-{enable-event(1),event-rule(7)}: `--filter` is not always avail.

The `--filter` option of both lttng-enable-event(1) and a common event
rule specification is not available with the Linux kprobe, kretprobe,
and user space probe instrumentation point types.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2cea488359bbe8ac8494d785fe3282419ee66d46

lttng(1)/lttng-create(1): document `--relayd-path`

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I83d65e13834593c97e296db2505dc97f6a8e4568

doc/man: document `LTTNG_SESSIOND_PATH` env. var. like `--sessiond-path`

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie6ff3f2f1003d506e5d4a351af0f811b4ca8b556

lttng-save(1): document `--all` option in "SYNOPSIS" and "DESCRIPTION"

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I895e2c8277cb8c1b7644f6d8607cd77230706515

Fix: snapshot path have domain subdir duplicate "ust/ust" or "kernel/kernel"

Observed issue
==============

lttng-ivc observed unexpected path generated for streamed snapshot:

  joraj-alpa/
   test-20190319-120000-20210113-110101/
    snapshot-1-20210113-110102-0/
*     ust/
*      ust/
        pid/
         app-ust-2362198-20210113-110101/
           channel_0
           channel_1
           metadata
           channel_2
           channel_3

"ust" the domain subdir is present two-time instead off only one time.

The same problem is seen for kernel snapshots.

Cause
=====

Based on dissection the problem was introduced by commit
5da88b0f58d7f838068037ea449ddfb25d3e85ad [1]

For snapshots, the consumer output object of the snapshot output and
information is fetched from the *original* consumer output.
(code block around src/bin/lttng-sessiond/cmd.c:4748)

The snapshot consumer output does not contains the necessary information
to populate domain_subdir on copy (domain_subdir is '\0').

This would lead to a len evaluation of 1 for the consumer_path_offset in
setup_channel_trace_path:70. This would end up not "skipping" the "ust"
and "kernel" part of the path.

Solution
========

Part of the solution is to copy the domain_subdir from the original
session consumer output to the snapshot output.

Still, the problem was still present since that now that the
domain_subdir was not "\0", the value was suffixed to the passed
session_path. In the snapshot code path, "ust/" and "kernel/" were
already present in the session_path passed to setup_channel_trace_path.

A quick modification at the caller level in the snapshot code path fixes
the issues once and for all.

Tests
=======

The test suit is augmented for certain key tests to validate the
complete path of a trace.

Path validation is based on crude bash pattern matching.

Known drawbacks
=========
None

References
==========
[1] https://github.com/lttng/lttng-tools/commit/5da88b0f58d7f838068037ea449ddfb25d3e85ad

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie7cd2d5471ee3a942fa511e2f4cab09e3aa499e4

Fix: error: remove trailing period from error descriptions

Trailing periods in some error descriptions cause the client to print
two dots at the end of some error messages:

Error: Failed to register trigger: Tracing the kernel requires a root
lttng-sessiond daemon, as well as "tracing" group membership or root
user ID for the lttng client..

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib6522252fb716b1baad3c7416e2db150c614702c

Make the subitems array a part of action_work_item

Make the subitems array a part of action_work_item instead of allocating
it dynamically when a trigger is enqueued for a given action executor.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I474e43ba3ba9267d629d3ce561c8677c90bddf27

Test: fix: firing policy name has changed

The firing policy name from "after every" to "every" in 4edabba83. The
tests are adapted to reflect this change.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic563c8ce959a6876e1300079ed236c83072efc58

lttng-add-trigger(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iac386141968106e648da67498696ecba9524491e

lttng-add-context(1): add usage examples

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I8ce928325a659676210ea9d2647ce7223f9527aa

list_triggers.c: replace "after every" -> "every"

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: If6121fda5bb6d7cf5c941c1ca134191c72518422

Fix: add_trigger.c: `goto error` with a wrong UID for `--owner-uid`

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I8650af1f43e8ed8bad58a928cfcdf78d382212f1

lttng-add-context(1): use a description list to explain `--channel`

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie2d701820bf1e086205254c0712fe088c3295b2d

doc/man/manpage.xsl: indent the body of formal (example) blocks

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I184b1bc54728cf0d770bc44f9f0923b9f8724396

doc/man: lttng(1) command pages: always include `common-footer.txt`

The end of an lttng(1) command manual page source now looks like this:

    include::common-lttng-cmd-help-options.txt[]

    include::common-lttng-cmd-after-options.txt[]

    include::common-footer.txt[]

`common-lttng-cmd-after-options.txt` contains the "EXIT STATUS",
"ENVIRONMENT", and "FILES" sections.

`common-footer.txt` begins with the "RESOURCES" section.

This will make it possible to insert an "EXAMPLES" section between
`common-lttng-cmd-after-options.txt` and `common-footer.txt`.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I1eee42d7386f4671d9825e9d3e131e54f868ee39

doc/man: follow man-pages(7) for section names/order and for "SEE ALSO"

Changes, following the "Sections within a manual page" section of
man-pages(7):

* Rename the "ENVIRONMENT VARIABLES" section to "ENVIRONMENT".

* Rename the "COPYRIGHTS" section to "COPYRIGHT".

* Move the "EXIT STATUS" section immediately after the "OPTIONS"
  section.

* Remove the "BUGS" section.

  Such a section indicates known bugs (why would you ever have such
  a section anyway?).

  The "RESOURCES" section now contains the URL of our bug tracker.

* Sort the manual pages by section, and then by name in the "SEE ALSO"
  section.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3d91073ec876efd98dcc723ddf40272c814663dd

Fix: action-executor: leak of `work_item::subitems` field

This leak can be reproduced by adding a trigger and looking at the used
memory of the lttng-sessiond process.

Valgrind reports the following leak:
  ==2472== 7,087,968 bytes in 147,666 blocks are definitely lost in loss record 24 of 24
  ==2472==    at 0x4C31B25: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
  ==2472==    by 0x191C37: zmalloc (macros.h:45)
  ==2472==    by 0x195234: action_executor_enqueue_trigger (action-executor.c:913)
  ==2472==    by 0x171AD7: dispatch_one_event_notifier_notification (notification-thread-events.c:4626)
  ==2472==    by 0x171D1E: handle_one_event_notifier_notification (notification-thread-events.c:4715)
  ==2472==    by 0x171DA4: handle_notification_thread_event_notification (notification-thread-events.c:4730)
  ==2472==    by 0x164EA6: handle_event_notification_pipe (notification-thread.c:591)
  ==2472==    by 0x1656C3: thread_notification (notification-thread.c:727)
  ==2472==    by 0x17BD16: launch_thread (thread.c:66)
  ==2472==    by 0x5F086DA: start_thread (pthread_create.c:463)
  ==2472==    by 0x624188E: clone (clone.S:95)

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3d98e3ae18c5b2d7f400407842a7de17716f680c

lttng: change a few instances of trigger "id" to "name"

The term trigger "id" has been changed to trigger "name", these are
leftovers. Fix them.

Change-Id: Ic05925af1cd25917de75a0a4d061324604e5a599
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Change "event rule hit" to "event-rule matches" in user interface strings

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

Change-Id: I619c9265d68ca6bf4a3ac11ef38cabc715b01110
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: relayd: live: data is missing between viewer attach and retry

Observed issue
==============

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

Using the following reproducer:

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

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

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

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

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

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

  # Here data is received correctly.
  date
  sleep 40
  date

  kill $pid
  wait

  lttng destroy live
  pkill lttng-relayd

Cause
=====

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

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

Solution
========

Always use `LTTNG_VIEWER_SEEK_BEGINNING` during
`viewer_get_new_streams`.

Known drawbacks
=========

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

References
==========

https://lists.lttng.org/pipermail/lttng-dev/2021-May/029953.html

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I92fbe6511fb93e31d20922b4eef5c9a221e07716

Build fix: filter-grammar-test: incorrect inclusion flag

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

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iff7b6e7000d907dc076a467d223c91569b783861

Tests: fix: test_tp_fail: bail out on non-existing relay daemon

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

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

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

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I02e7f35451b3c81e7e808e9ff96b6c824fa8f904

build system: support rotation example

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Icf5f88dcc725967b7fda66db6e047cdf18a89f01

Add trigger on event rule matches application example

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ice78e15aa1f4380925a272def8bcc7ca331c0aa0

Update the remaining manual pages for LTTng-tools 2.13

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

This patch:

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

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

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

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

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

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

* Updates existing manual pages to:

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

  * Fix various terminology ambiguities.

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

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

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

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

  * Clean the "SEE ALSO" sections.

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

  More specifically:

  lttng-create(1):
      * Clarify the tracing session modes.

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

      * Specify that `--output=DIR` is equivalent to
        `--set-url=file://DIR`.

  lttng-enable-channel(1):
      Include the `--discard`, `--buffers-uid`, and `--buffers-global`
      options in the "SYNOPSIS" section even if they are the current
      defaults.

  lttng-list(1):
      Explain what this command does exactly using a tree of options
      and arguments.

  lttng-load(1):
      Clarify how LTTng finds tracing session configurations.

  lttng-relayd(8):
      * Document the missing `--group` option.

      * Rework the text in general.

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

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

  lttng-rotate(1):
      Specify that the `rotate-session` trigger action can also rotate
      a tracing session.

  lttng-save(1):
      Clarify the output path.

  lttng-sessiond(8):
      Add more cross-references between options and equivalent
      environment variables.

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

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

  lttng-track(1):
  lttng-untrack(1):
      * Simply refer to allowing processes to record events and to
        process attribute inclusion sets instead of using the vague
        "tracker" terminology.

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

      * Improve the documentation of each inclusion set selection
        option.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iac7498ee979fe077f0927a9b8335f6c07f203989

doc/man/manpage.xsl: do not indent the title of an admonition block

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

I copied and modified some upstream DocBook XSL (as found in
`xsl/manpages/block.xsl`).

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I765ce37957907edb4088a4212c1b12af8b485e60

Fix: lttng: add-trigger: invalid access past end of exclusions buffer

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

Running with valgrind results in the following report:

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

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

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

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

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Icbb7f0e8601c7ecc887dc9ae64d0ec6390e6aba3

Fix: tests: extra arguments are not passed to the remove trigger command

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

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

Solution
========
Pass all extra parameters for the command execution.

Known drawbacks
=========

None.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic7b5d46b6793cda16a474c5459f9bf533812fe61

Fix: lttng-ctl: erroneous check if user is part of the tracing group

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

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

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

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I614da0123d0546c5f54f121e8ed9716d6e292400

Build fix: kernel-consumerd: merge conflict left in file

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I71defaee6724a08661567af879b91a57d9dae74c

Clean-up: consumerd: use a specific status code for get_next_subbuffer

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

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

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

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ibdb2837396e4b8cd291ffd80f6ca59b39ce3f707

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

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

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

sessiond: remove commented-out logging

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I7b8991ba994585fd8f2b5c6e02b9be7cf8e7123b

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

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

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

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