This also gives us an opportunity to improve the error reporting.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97008
Signed-off-by: Simon McVittie <smcv@debian.org>
Reviewed-by: Thiago Macieira <thiago@kde.org>
In Debian bug <https://bugs.debian.org/829348>, lightdm appears to
have been starting dbus-launch with at least one of the three
standard fds 0, 1, 2 (stdin, stdout, stderr) closed. This resulted
in the dbus-daemon's epoll_create1() returning a fd less than 3.
Later, _dbus_become_daemon() replaces fds 0-2 with /dev/null. As a
result, a subsequent call to _dbus_loop_add_watch() for the reload
pipe resulted in calling epoll_ctl on the non-epoll fd pointing to
/dev/null, which fails with EINVAL, resulting in the dbus-daemon
exiting unsuccessfully.
Unix programs are not normally expected to behave correctly when
launched with the standard fds not already open; but at the same time,
X11 autolaunching means that dbus-launch (and hence the dbus-daemon)
can get started from an arbitrarily precarious situation.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97008
Signed-off-by: Simon McVittie <smcv@debian.org>
Reviewed-by: Thiago Macieira <thiago@kde.org>
This function opens stdin, stdout, stderr pointing to /dev/null
if they aren't already open. Optionally, it can also replace
whatever is available on those fds with /dev/null.
To allow for use in contexts where only async-signal-safe functions
should be used, such as between fork() and a following exec(),
this function does not use conventional libdbus error handling
(which would require malloc). Instead, it sets errno and returns
an explanatory string.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97008
Signed-off-by: Simon McVittie <smcv@debian.org>
Reviewed-by: Thiago Macieira <thiago@kde.org>
This is more suitable for distributions' Xsession scripts: it verifies
that X is already available, and so never results in an attempt to poll
stdin.
We read the machine UUID because it is needed to set the X atoms.
x11_init() assumes that the machine UUID (global variable) has been
set, either via read_machine_uuid_if_needed() or save_machine_uuid().
This is pretty tangled, but to make The Right Thing happen
automatically, we'd need to redo dbus-launch in terms of DBusError.
Reviewed-by: Will Thompson
Reviewed-by: Thiago Macieira
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=39197
Signed-off-by: Simon McVittie <smcv@debian.org>
XML_Parse() can potentially return values other than OK (1) or ERROR (0),
and they aren't errors.
Signed-off-by: Deepika Aggarwal <deepika.a@samsung.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=93205
[smcv: improve commit message, fix whitespace]
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
The NULL-dereference is not actually possible in this case, because we
know that the allocation and setup were done previously.
Signed-off-by: Deepika Aggarwal <deepika.a@samsung.com>
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=93210
This is an attempt to make that section a little clearer. I don’t think
any factual inaccuracies have been fixed (because I couldn’t find any).
Including some wording and an example by Simon McVittie.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=93382
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
If dbus is running as systemd service, dbus daemon is running with
oom_score_adj -900 by OOMScoreAdjust=-900. And children will also have
same value with dbus daemon.
To avoid this, set the child itself values after fork () to 0.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=32851
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Some D-Bus daemon versions set multiple addresses separated by semi-colon,
which breaks sourcing of the file.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=94746
Signed-off-by: Thiago Macieira <thiago@kde.org>
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Some D-Bus daemon versions set multiple addresses separated by semi-colon,
which breaks sourcing of the file.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=94746
Signed-off-by: Thiago Macieira <thiago@kde.org>
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Also enable segfault checks on windows because the reason why it
has been disabled has been fixed with bug #95155.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=95191
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
This should detect anything that is only a build failure when embedded
tests or verbose mode are enabled, such as the missing include fixed
in commit 4858faf. I'm not enabling embedded tests and verbose mode
orthogonally because we don't want CI builds to take too long.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Ralf Habacker <ralf.habacker@freenet.de>
Ensure that the babysitter thread already owns its one reference to the
babysitter when it starts up, and eliminates the race condition.
This patch requires that DBusBabysitter refcounting is thread-safe
and is based on an analysis and proposal of Simon Mc Vittie.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=95191
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Previously, the listen() backlog was set to an arbitrary 30. This means
that if dbus-daemon is overloaded only 30 more connections may be queued
by the kernel, before connect() fails with EAGAIN. (Note that EAGAIN !=
EINPROGRESS -- the latter is what is returned if a connection is queued
and being processed for asynchronous sockets; EAGAIN in this case is
really an error, that cannot be recovered from).
Most software simply sets SOMAXCONN as backlog for AF_UNIX sockets, to
allow queuing of as many connections as the kernel allows. SOMAXCONN is
128 on Linux, which is not particularly high, but at least higher than
30.
This patch changes dbus-daemon to do the same.
I noticed this when flooding dbus-daemon with a lot of connections,
where it pretty quickly ceased to respond, much earlier than it really
should.
Note that the backlog has nothing to do with the number of concurrent
connections allowed, it simply controls how many queued, but not
accept()ed connections there may be on the listening socket.
https://bugs.freedesktop.org/show_bug.cgi?id=95264
