Fix: don't ask data pending if session was not started

Fixes #770

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: take session list lock when listing tp

This is important since the list tracepoints command access the
application socket to ask the application for its TPs. The session list
lock protects the ordering of message for those sockets.

This was triggering out of order message between the session daemon and
an application thus triggering undefined behavior.

Fixes #774

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: don't print stream name in error message

The stream received, in per UID, is actually a temporary stream object
that only contains the UST object data which is the relevant part for
UST to use.

Thus on error the name was random data thus print the valid handle
descriptor instead of invalid data.

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: incorrect printf format

Fixes #777

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: handle ENOENT when creating a kernel event

The kernel tracer returns ENOENT if an event is not found thus warn the
user of that.

Fixes #761

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: deny overwrite mode and num subbuf less than 2

Also fixed in UST and modules with commit:

(modules) 5140d2b3070f211e6d8a0ad7cb0a190e8b6f3e28
(ust) 3d8e9399b2fb9000b3b55e488a7d04184b5bb56e

Fixes #793

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: possible use after free in consumer

Fixes the coverity issue 1019959.

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: Add vpid, vppid and vtid info in add-context help

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: set session in output mode if URL are set afterwards

Fixes #809

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: static array larger than necessary

The longest string that can be returned should be 20 chars long, as per
the comment.

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: check malloc return value

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: don't set enabled flag is session start fails

The "started" var. is changed to the flag "has_been_started" indicating
if at least ONE start command has been seen.

The "enabled" var. is changed to the flag "active" and the semantic is
the same.

Backported from master.

Signed-off-by: David Goulet <dgoulet@efficios.com>

Fixes #801

Conflicts:
	src/bin/lttng-sessiond/cmd.c