https://github.com/systemd/systemd/pull/14133 made
capability_ambient_set_apply() acquire capabilities that were explicitly
asked for and drop all others. This change means the function is called
even with an empty capability set, opening up a code path for users
without ambient capabilities to call this function. This function will
error with EINVAL out on kernels < 4.3 because PR_CAP_AMBIENT is not
understood. This turns capability_ambient_set_apply() into a noop for
kernels < 4.3
Fixes https://github.com/systemd/systemd/issues/15225
Functions called from device_setup_unit() already make sure that unit is
enqueued in case it is a new unit or properties exported on the bus have
changed.
This should prevent unnecessary DBus wakeups and associated DBus traffic
when device_setup_unit() was called while reparsing /proc/self/mountinfo
due to the mountinfo notifications. Note that we parse
/proc/self/mountinfo quite often on the busy systems (e.g. k8s container
hosts) but majority of the time mounts didn't change, only some mount
got added. Thus we don't need to generate PropertiesChanged for devices
associated with the mounts that didn't change.
Thanks to Renaud Métrich <rmetrich@redhat.com> for debugging the
problem and providing draft version of the patch.
I put the helper functions in a separate header file, because they don't fit
anywhere else. pthread_mutex_{lock,unlock} is used in two places: nss-systemd
and hashmap. I don't indent to convert hashmap to use the helpers, because
there it'd make the code more complicated. Is it worth to create a new header
file even if the only use is in nss-systemd.c? I think yes, because it feels
clean and also I think it's likely that pthread_mutex_{lock,unlock} will be
used in other places later.
On azure systemd.systemd ci, the build would fail with:
meson.build:53:0: ERROR: Program or command '/home/appuser/fuzzer/tools/add-git-hook.sh' not found or not executable
We use find_program() for all helpers, so let's do it for this one too.
This should solve the issue, whatever it exactly is.
It is more trouble than it is worth. The setup is of a loopback device
is very quick, so it's better to always create it when needed and
immediately drop afterwards.
This causes the unprivileged-nspawn-root directory to be removed
after running one test. The advantage is that we reduce the maximum
disk-space use quite a bit (47*400 MB → about 18GB).
has-overflow was a temporary hack that was removed in
844da987ef (Oct. 2016). All the makefiles
can be the same, and all the targets can be handled identically.
Before, we'd copy the test tree into nspawn-root, and run the tests from there.
This is OK, and doesn't actually take much extra time. But it uses quite a lot
of extra disk space. So let's make things a bit more efficient by running
directly from the image file.
We still run the unprivileged nspawn tests from a copy. Once the kernel
implements fs shift, we can do away with that too.
Before, we'd create a separate image for each test, in
/var/tmp/systemd-test.XXXXX/rootdisk.img. Most of the images
where very similar, except that each one had some unit files installed
specifically for the test. The installation of those custom unit files
was removed in previous commits (all the unit files are always installed).
The new approach is to only create as few distinct images as possible.
We have:
default.img: the "normal" image suitable for almost all the tests
basic.img: the same as default image but doesn't mask any services
cryptsetup.img: p2 is used for encrypted /var
badid.img: /etc/machine-id is overwritten with stuff
selinux.img: with selinux added for fun and fun
and a few others:
ls -l build/test/*img
lrwxrwxrwx 1 root root 38 Mar 21 21:23 build/test/badid.img -> /var/tmp/systemd-test.PJFFeo/badid.img
lrwxrwxrwx 1 root root 38 Mar 21 21:17 build/test/basic.img -> /var/tmp/systemd-test.na0xOI/basic.img
lrwxrwxrwx 1 root root 43 Mar 21 21:18 build/test/cryptsetup.img -> /var/tmp/systemd-test.Tzjv06/cryptsetup.img
lrwxrwxrwx 1 root root 40 Mar 21 21:19 build/test/default.img -> /var/tmp/systemd-test.EscAsS/default.img
lrwxrwxrwx 1 root root 39 Mar 21 21:22 build/test/nspawn.img -> /var/tmp/systemd-test.HSebKo/nspawn.img
lrwxrwxrwx 1 root root 40 Mar 21 21:20 build/test/selinux.img -> /var/tmp/systemd-test.daBjbx/selinux.img
lrwxrwxrwx 1 root root 39 Mar 21 21:21 build/test/test08.img -> /var/tmp/systemd-test.OgnN8Z/test08.img
I considered trying to use the same image everywhere. It would probably be
possible, but it would be very brittle. By using separate images where it is
necessary we keep various orthogonal modifications independent.
The way that images are cached is complicated by the fact that we still
want to keep them in /var/tmp. Thus, an image is created on first use and
linked to from build/test/ so it can be found by other tests.
Tests cannot be run in parallel. I think that is an acceptable limitation.
Creation of the images was probably taking more resources then the actual
tests, so we should be better off anyway.
We had an fstab for the sole purpose of remounting "/" rw. Mounting root ro
is a pointless excercise in obsolete approaches. More importantly, the nspawn
image is now the same as the qemu one.
