Fix: per-uid flush and ust registry locking

Commit c4b88406 "Fix: ust-app: per-PID app unregister vs tracing stop
races" introduces a regression for per-UID flush. It can be triggered by
the test_high_throughput_limits (root regression) test. For per-UID
tracing, we need to use the registry channel ID, not the per-application
channel ID, when asking the consumer daemon to flush.

When doing this fix, we notice that the locking rules of push_metadata()
are weird. A per-ust app session lock is protecting registry data, which
makes it impossible to call push_metadata from a ust session level (for
the entire session) in the case of per-UID tracing. Moreover, it's
unclear how holding a per-application lock can protect a registry shared
across applications in per-UID tracing. Therefore, we move all accesses
to the registry metadata_key and metadata_closed fields into the
registry lock critical section. We now only rely on RCU to ensure
existance of registry across push_metadata(), rather than relying on the
per-application session lock.

It also takes care of a documentation vs code mismatch: push_metadata()
documents that "The session lock MUST be acquired here before calling
this.", but in reality, it's the application session lock which is held
across those calls. Removing this requirement, and relying on RCU
instead, fixes this mismatch.

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

Docs: Missing optional dependency on lttng-ust in README.md

Reported-by: Jonathan Rajotte <jonathan.rajotte@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Docs: Grammar fixes in the lttng manpage

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

Fix: add missing UST perf counter support check

Report whether performance counters are supported by UST on the
architecture as soon as the user try to enable a perf counter context.

Fixes #851

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

Fix: tests: integer too large for long type

Compiler warns on 32-bit builds.

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

Fix: undefined operation on last_relay_viewer_session_id

Triggers compiler warning on 32-bit build.

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

Fix: print format type mismatch

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

Fix: print format type mismatch

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

Fix: Remove structurally dead code from relayd

CID 1262070:  Structurally dead code  (UNREACHABLE)

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

Cleanup: Remove logically dead code

*** CID 1262071:  Logically dead code  (DEADCODE)
/src/bin/lttng-sessiond/ht-cleanup.c: 130 in thread_ht_cleanup()

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

Cleanup: Remove unused label

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

Fix: Remove unused argument in debug statement

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

Fix: exit threads not only on goto restart

Exit threads as soon as number of FD is 0, on every loop (no need for
goto restart special case). Number of FD being 0 is a sufficient
condition for exiting the thread: it means the quit pipe has been
removed from the poll set.

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

Fix: poll: show the correct number of fds

LTTNG_POLL_GETNB() uses wait nb_fd, which is only updated after
lttng_poll_wait returns.

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

Fix: call lttng_poll_set_max_size before start threads

This changes the location of lttng_poll_set_max_size() call within
sessiond main() to call it before creating the ht_cleanup thread. This
fix is only needed on top of the main refactoring patch.

This fix also adds checks for lttng_poll_set_max_size() error values.

Fixes #747

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

Fix: compat poll: add missing empty revents checks

Poll returns the entire array, including entries that have no activity.
We need to check them explicitly.

Fixes #747

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

Fix: various compat poll/epoll issues

poll:
- fix two nb_fd off by one in "add",
- simplify array size calculation,
- add error checking,
- compress the content of array before resizing it on "del"
  (out-of-bound memory access issue),
- set wait.nb_fd = 0 when no FD are present in array on wait,
- remove need_realloc flag: this can be checked internally by comparing
  current->alloc_size and wait->alloc_size. Minimize the number of
  duplicated state.

epoll:
- add error checking,
- simplify array size calculation (make it similar to poll),
- Set default size when poll_max_size is 0 within
  compat_epoll_set_max_size(), which allow better error checking
  elsewhere in epoll compat code.

Fixes #747

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

Add debugging output to ht-cleanup thread

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

Fix: mi: snapshot: missing error handling for session name

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

Fix: ust-app: per-PID app unregister vs tracing stop races

There are various races with UST application unregister performed
concurrently with tracing stop operation when tracing with per-pid
buffers. This randomly affects availability of data shortly after the
data pending check returns that no more data is available.

ust_app_stop_trace_all() iterates on all applications in the ust_app_ht
hash table to issue a flush on all buffers. This is needed to ensure
that the sub-buffers being written to are made available to the
consumer, for both data consumption, and for the data pending check.
Failure to execute the sub-buffer flush makes following data pending
check return that there is no data in the buffers too early, thus
resulting in an incomplete trace.

It is therefore important that an application flushes all its buffers
before it is removed from the ust_app_ht.

This is where ust_app_unregister() needs to be fixed. Note that
ust_app_unregister() executes concurrently with
ust_app_stop_trace_all(), only taking the per-session lock. The order of
flush vs hash table removal therefore matters:

We need to push the metadata before removing application from
ust_app_ht. We also need to issue a flush for all application buffers
before removing the application from ust_app_ht.

Once this is fixed, there is yet another race, this time in
ust_app_flush_trace() (now renamed ust_app_flush_session()). It is
caused by the use of ustctl_sock_flush_buffer() which asks the
application to perform the buffer flush. Unfortunately, if the
application vanishes (not reachable anymore), but its unregistration has
not yet been processed by sessiond, then ust_app_stop_trace_all() will
fail to flush the application buffers, because
ustctl_sock_flush_buffer() will fail.

This final issue is fixed by asking the consumer daemon to flush the
associated channel rather than relying on the application.

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

Fix: data pending: allow empty streams

There are cases where a stream can be completely empty (no packet to
write) with UST: for instance, if a traced application is either
preempted for a long time, terminated, or stopped, between reserve and
commit. This will make the consumer consider that this stream has no
data ready. If this situation occurs in the first sub-buffer of a
stream, this stream will have no data at all (0 bytes).

Therefore, we need to let the data pending check consider that no data
is pending in this situation, otherwise it can make the data pending
check always return that there is data pending.

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

Fix: ust snapshot: cleanup after error

The "break" statement on error skips the rest of the functions, thus
leaving test applications running after the end of the test, which is a
side-effect on the following tests.

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

Fix: Mismatching return type in ust_app_ht_alloc() stub

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

Cleanup: lock file already taken is error, not warning

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

Fix: ust-app null pointer check needed for main refactoring

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

Cleanup: relayd: centralize thread stopping function

Rather than relying on having main.c and live.c threads both using the
same notification pipe from different stop_thread implementations,
centralize thread stop in one central function exposed to both main.c
and live.c

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

Cleanup: Replace all perror() uses by the PERROR macro

PERROR prints the perror() message in our own logging format rather
than going straight to stderr.

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

Refactor relayd main/set_options/cleanup

- Enforce symmetry between allocation and teardown,
- Handle all errors,
- Return all errors as EXIT_FAILURE,
- Standardize on zero being success, nonzero being error,
  (rather than < 0 being error),
- Fix pthread PERROR: we need to store ret into errno before
  calling PERROR, since pthread API does not set errno,
- Join errors now fall-through, rather than rely on the OS
  to teardown the rest.

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

Refactor consumerd main/cleanup

- Enforce symmetry between allocation and teardown,
- Handle all errors,
- Return all errors as EXIT_FAILURE,
- Standardize on zero being success, nonzero being error,
  (rather than < 0 being error),
- Fix pthread PERROR: we need to store ret into errno before
  calling PERROR, since pthread API does not set errno,
- Join errors now fall-through, rather than rely on the OS
  to teardown the rest.

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

Refactor sessiond main/cleanup/ht-cleanup

Main reason for this entire patchset: move teardown of ht-cleanup thread
_after_ the sessiond cleanup which needs to destroy hash tables. This
fixes leaks at sessiond teardown that makes the valgrind output hard to
use. As this has been done, various other issues with error handling,
leaks, and symmetry of allocation and teardown have been fixed, which
makes this a refactoring.

- Enforce symmetry between allocation and teardown,
- Handle all errors,
- Return all errors as EXIT_FAILURE,
- Standardize on zero being success, nonzero being error,
  (rather than < 0 being error),
- Fix pthread PERROR: we need to store ret into errno before
  calling PERROR, since pthread API does not set errno,
- Join errors now fall-through, rather than rely on the OS
  to teardown the rest.

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

Missing error handling: consumer_signal_init should return its error status

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

Cleanup: consumerd: lines over 80 columns

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

Cleanup: consumerd: use PERROR rather than perror

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Cleanup: lttng-consumerd: remove stale TODO comment

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

Misleading error handling: utils_create_pid_file() should return 0 on success

fprintf returns a positive value on success, which is used as return
value for utils_create_pid_file(), which is odd. This is in preparation
for main() refactoring.

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

Missing error handling: consumerd parse_args should return errors to caller

In preparation for having main() handle the return value.

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

Missing error handling: ust_app_ht_alloc should return error status

In preparation for having sessiond main() handle the error.

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

Fix: ust app leak on UST buffer creation error

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

Fix: leak on UST buffer registry creation error

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

Fix: agents ht leaks on destroy session

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

Fix: add missing RCU read unlock

Master commit 24eb8569dc841f318d7964ca9a0ad0a4f9508a8e
"Fix: Missing RCU read locks in syscall_list_channel()"

Introduces unbalanced RCU read-side lock/unlock. Should be applied to
master and stable-2.6.

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

Fix: help message for Python agent mentions Java

Bad copy/paste.

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

Fix: don't destroy the sockets if the snapshot was successful

Missing a goto to skip the error condition that was destroying the
relayd sockets even if a snapshot was successful. We want to keep them
open to reuse them for the next snapshots.

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

Fix: Missing RCU read locks in syscall_list_channel()

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

Fix: Missing RCU read lock in kernel_destroy_session()

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

Fix: channel names are not validated

This patch ensures:

  1. A channel name does not contain any '/' character, since
     relative paths may be injected in the channel name
     otherwise (knowing that the channel name is eventually
     part of a file name)
  2. A channel name does not start with a '.' character, since
     trace readers (Babeltrace is one of them) could interpret
     files starting with a dot as hidden files and ignore
     them when opening the CTF trace

Fixes: #751
Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Cleanup: Missing whitespace

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

Fix: Apply consumer URI changes to all domains

See the associated bug report for a lenghty explanation of the issue
and of this fix. It fixes an issue when saving a live session's
configuration that was created by loading an .lttng file.

Fixes #866

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

Cleanup: Fix a typo in the MI tests

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

Test fix: Don't invoke the system's lttng client

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

Tests: Add a test to check disabled events are loaded in the correct state

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

Fix: Don't leave events enabled if they were saved in a disabled state

Events are enabled by default on creation. The session configuration
loader must make sure to disable them after creation when restoring an
event that was saved in the "disabled" state.

Reported-by: Marcel Hamer <marcel.hamer@ericsson.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: "Any" loglevel's value is -1 and not 0

lttng_disable_event_ext() was erroring-out on loglevel != 0.
loglevel 0 is a valid level whereas "-1" is used an unknown/unspecified
in the rest of the code.

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

Test fix: LTTNG_SESSION_CONFIG_XSD_PATH expects an absolute path

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

Fix: Memory leak on error in alloc_argv_from_user_opts()

*** CID 1256181:  Resource leak  (RESOURCE_LEAK)

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

Cleanup: Unchecked close() return value in utils_create_lock_file()

*** CID 1226188:  Unchecked return value  (CHECKED_RETURN)

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

Cleanup: No check of the return value of lttng_ht_del()

*** CID 1230590:  Unchecked return value  (CHECKED_RETURN)

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

Cleanup: Mixed enums used for return code in send_sessiond_channel()

*** CID 1132649:  Inferred misuse of enum  (MIXED_ENUMS)

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

Cleanup: Cast poll() return value to void

*** CID 1019969:  Unchecked return value from library  (CHECKED_RETURN)

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

Fix: Unreachable error logging in set_option()

*** CID 1256136:  Logically dead code  (DEADCODE)

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

Fix: OOM leaks in sessiond modprobe.c

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

Cleanup: sessiond modprobe.c: coding style

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

Cleanup: test_utils_expand_path.c prototypes

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

Fix: test_utils_expand_path.c: out of memory error handling

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

Fix: test test_ust_data.c: check OOM

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

Fix: test libc-wrapper: check malloc OOM

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

Cleanup: test libc-wrapper: main parameters

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

Fix: lttng-ctl: use zmalloc(), missing OOM check

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

Fix: filter-parser.y: use zmalloc(), missing OOM check

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

Fix: utils.c: check str*dup OOM

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

Cleanup: implement zmalloc as static inline

Whenever we can implement as static inline rather than macro, it's
better (type checking of arguments, less chances of hitting preprocessor
aweful semantic corner-cases....).

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

Fix: rculfhash: use zmalloc()

Follow lttng-tools rules.

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

Fix: ini.c: use zmalloc()

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

Fix: lttng lttng.c: check strdup OOM

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

Fix: lttng conf.c: use zmalloc()

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

Fix: lttng view.c missing strdup OOM check

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

Fix: use zmalloc() in lttng view.c

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

Fix: use zmalloc() in lttng list.c

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

Fix: oom error check, realloc oom leak

print_exclusions can return a NULL pointer on OOM, should be checked.
Also, realloc always need to store result in a different variable than
its input in case it fails (and its returned pointer needs to be checked
for NULL).

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

Fix: use zmalloc in lttng enable_events.c

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

Fix: missing strdup oom check in lttng create.c

Introduce tmp_path to ensure that no code path can possibly try to free
the return value of utils_get_home_dir(). Re-using alloc_path for both
static and dynamically allocated pointer is error-prone.

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

Fix: lttng add_context.c: use zmalloc

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

Cleanup: add missing static to function modprobe_remove_lttng()

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

Fix: add missing str*dup oom check in sessiond main.c

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

Fix: add missing sessiond kernel-consumer missing str*dup oom checks

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

Fix: add missing strdup OOM check

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: add missing synchronization point for before app test case

Fixes a race where the application could generate all its events before
trace start.

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

Fix: tests: wait output hide Terminate errors

Also: Don't hide kill errors.

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

Fix: tests: remove killall, add missing SIGTERM handlers

Applications may change name and, thus, be missed by using
killall.

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

Fix: high throughput test: reset bw limit on sigterm

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

Fix: tests: add missing wait, document missing synchro

Move all wait ${!} that target a single process to "wait", to minimize
the chances to forget some background process in the future.

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

Document test anti-patterns

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

Fix: test flaky sleep and wait patterns

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

Fix: tests: don't use pidof to wait for test apps

Use the bash shell "wait" to wait for all background tasks rather than
the racy "pidof". Indeed, it's possible that applications have been
forked, but not executed yet, when pidof is done, which would therefore
miss applications. Using "wait" from the shell solves this.

If we want to be really strict, we should have sessiond, consumerd, and
relayd export a file containing their own PID, and wait for this instead
of using pidof. But this will be for another fix.

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

Fix: Live tracing does not honor live timer after first tracefile with tracefile rotation

When we pass to the 2nd sub-file (or following sub-files) of a stream in
relayd, the live timer has no visible effect from a live reader
perspective, and then everything is flushed when we reach the following
sub-file.

This is caused by the reset of stream->total_index_received after each
tracefile rotation. It should keep on incrementing to match what is
expected by check in check_index_status():

  (rstream->total_index_received <= vstream->last_sent_index)

Fixes #863

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

Fix: Handle empty daemon configuration file lines

Empty daemon configuration file lines such as
my_option=

will cause set_option to be called with an arg value of length 0
which should display a warning.

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

Docs: Add -f/--config option to lttng-sessiond man page

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

Cleanup: spaghetti function return path

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

Fix: relayd: unbalanced RCU read-side lock/unlock

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

Fix: relayd: unbalanced RCU read lock/unlock

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