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>
(cherry picked from commit c8f73a2a3a)
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>
(cherry picked from commit 69123a6bd2)
It should probably be used (see #97298) but the fact that it isn't
is breaking compatibility with gcc 6, so apply a quick workaround
while we look into what's wrong here.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97282
(cherry picked from commit 21d6118081)
If dbus-daemon or systemd replied to our method call with an error,
we would report it as "invalid arguments" instead of the true error
name and message.
Same root cause as <https://bugs.freedesktop.org/show_bug.cgi?id=96653>.
Signed-off-by: Simon McVittie <smcv@debian.org>
Otherwise HAVE_STDINT_H will not be defined or the var will not be
picked up from cache so builds could fail with errors like:
| ../../dbus-1.10.8/dbus/dbus-internals.h:239:8: error: ‘uintptr_t’ undeclared (first use in this function)
Signed-off-by: Ioan-Adrian Ratiu <adrian.ratiu@ni.com>
[smcv: fix Autoconf underquoting]
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>
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>
(cherry picked from commit 8f6fe1451e)
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, 64-bit (LP64 or LLP64) platforms would have had 32 bits
of padding between pad2 and pad3. We want to guarantee that an ISO C
compiler will copy the entire struct when assigning between structs,
but padding is not guaranteed to be copied, so we want to ensure that
the struct is "packed".
Statically assert that the old ABI is compatible with the new ABI.
Reviewed-by: Thiago Macieira <thiago@kde.org>
[smcv: change >= to == as Thiago requested]
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=94136
We already asserted that DBusMessageIter must be at least as large
as DBusMessageRealIter (so that casting DBusMessageIter * to
DBusMessageRealIter * does not result in overflowing the stack
variable). Also assert that it must have alignment requirements at
least as strict as those of DBusMessageRealIter * (so that casting
does not increase the required alignment).
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Thiago Macieira <thiago@kde.org>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=94136
This is useful when making static assertions about our types'
properties.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Thiago Macieira <thiago@kde.org>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=94136
