This allows us to build and install after booting without having to
build a new image. Together with
https://github.com/systemd/mkosi/pull/2601 and after enabling
RuntimeBuildSources=yes, after booting, "meson install -C /work/build"
can be used to do an incremental build and install. This won't build
proper packages, but will be invaluable for having a quick compile,
edit, test cycle without having to rebuild the image all the time.
networkd: report error if lease file cannot be loaded and ignore
On my system, networkd would report that interface ve-rawhide is "Failed"
without anything in the logs:
systemd-networkd[651095]: ve-rawhide: Trying to reconfigure the interface.
systemd-networkd[651095]: ve-rawhide: Gained IPv6LL
systemd-networkd[651095]: ve-rawhide: Link DOWN
systemd-networkd[651095]: ve-rawhide: Lost carrier
systemd-networkd[651095]: ve-rawhide: Configuring with /usr/lib/systemd/network/80-container-ve.network.
systemd-networkd[651095]: ve-rawhide: Link UP
systemd-networkd[651095]: ve-rawhide: Gained carrier
systemd-networkd[651095]: ve-rawhide: Failed
At debug level:
systemd-networkd[799993]: dhcp-server-lease/ve-rawhide:1:1: Missing object field 'Address'.
I'm not sure why "Address" is missing, but anyway, in this case, we should ignore the
lease file rather than refusing to configure the interface. Also, warn at the point
where we know what the filename is.
test-execute: check for s390x first and duplicate test
s390x will define both s390x and s390, so exec-personality-s390.service is ran
in both cases but fails on s390x, as the personality returned is s390x.
Split the test and check specifically for s390x.
Mike Yuan [Sun, 7 Apr 2024 11:33:37 +0000 (19:33 +0800)]
systemctl-logind: auto soft-reboot only if /run/nextroot/ is mountpoint
Consider the following case: a user sets up a minimum rootfs for
file system maintenance work in /run/nextroot/ dir directly. When
they're done, they expect 'systemctl reboot' to perform a full reboot.
But they keep soft-rebooting back to the tmpfs root, until they
find out about $SYSTEMCTL_SKIP_AUTO_SOFT_REBOOT.
So currently, when /run/nextroot/ is a normal dir, pid1 automatically
turns it into a bind mount to soft-reboot into. This is good, but when
combined with automatic soft-reboot it has an arguably unexpected
behavior, since /run/nextroot/ can never go away in such a case.
OTOH, if /run/nextroot/ is a mountpoint in the first place, the mount
is *moved* so a second reboot would not trigger auto soft-reboot.
Let's just make things more friendly to users, and do auto soft-reboot
only if /run/nextroot/ is also a mountpoint.
With gcc-14.0.1-0.13.fc40, when compiling with -O2, the compiler doesn't understand
that sd_bus_error_setf() always returns negative on error when <name> is provided:
[28/576] Compiling C object systemd-resolved.p/src_resolve_resolved-bus.c.o
../src/resolve/resolved-bus.c: In function ‘call_link_method’:
../src/resolve/resolved-bus.c:1763:16: warning: ‘l’ may be used uninitialized [-Wmaybe-uninitialized]
1763 | return handler(message, l, error);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
../src/resolve/resolved-bus.c:1749:15: note: ‘l’ was declared here
1749 | Link *l;
| ^
../src/resolve/resolved-bus.c: In function ‘bus_method_get_link’:
../src/resolve/resolved-bus.c:1822:13: warning: ‘l’ may be used uninitialized [-Wmaybe-uninitialized]
1822 | p = link_bus_path(l);
| ^~~~~~~~~~~~~~~~
../src/resolve/resolved-bus.c:1810:15: note: ‘l’ was declared here
1810 | Link *l;
| ^
...
Let's make the assertion a bit more explicit. With this, the warning goes away,
but I think it's more obvious to a human reader too.
core: silence gcc warning about unitialized variable
When compiled with -O2, the compiler is not happy about dynamic_user_pop() and
would warn about the output variables not being set. It does have a point:
we were doing a cast from ssize_t to int, and theoretically there could be
wraparound. So let's add an explicit check that the cast to int is fine.
[540/2509] Compiling C object src/core/libsystemd-core-256.so.p/dynamic-user.c.o
../src/core/dynamic-user.c: In function ‘dynamic_user_close.isra’:
../src/core/dynamic-user.c:580:9: warning: ‘uid’ may be used uninitialized [-Wmaybe-uninitialized]
580 | unlink_uid_lock(lock_fd, uid, d->name);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../src/core/dynamic-user.c:560:15: note: ‘uid’ was declared here
560 | uid_t uid;
| ^~~
../src/core/dynamic-user.c: In function ‘dynamic_user_realize’:
../src/core/dynamic-user.c:476:29: warning: ‘new_uid’ may be used uninitialized [-Wmaybe-uninitialized]
476 | num = new_uid;
| ~~~~^~~~~~~~~
../src/core/dynamic-user.c:398:23: note: ‘new_uid’ was declared here
398 | uid_t new_uid;
| ^~~~~~~
nsresourced: add new daemon for granting clients user namespaces and assigning resources to them
This adds a small, socket-activated Varlink daemon that can delegate UID
ranges for user namespaces to clients asking for it.
The primary call is AllocateUserRange() where the user passes in an
uninitialized userns fd, which is then set up.
There are other calls that allow assigning a mount fd to a userns
allocated that way, to set up permissions for a cgroup subtree, and to
allocate a veth for such a user namespace.
Since the UID assignments are supposed to be transitive, i.e. not
permanent, care is taken to ensure that users cannot create inodes owned
by these UIDs, so that persistancy cannot be acquired. This is
implemented via a BPF-LSM module that ensures that any member of a
userns allocated that way cannot create files unless the mount it
operates on is owned by the userns itself, or is explicitly
allowelisted.
BPF LSM program with contributions from Alexei Starovoitov.
dissect-image: make dissected_image_acquire_metadata() operate within a userns if possible
This opens the door for making the call work without privileges: if we
pass in a userns fd and DissectedImage that has mount fds then we can
acquire all information without privs.
lock-util: make global lock return parameter to image_path_lock() optional
When adding unprivileged nspawn support we don't really want a global
lock file, since we cannot even access the dir they are stored in, hence
make the concept optional.
uid-range: add new uid_range_load_userns_by_fd() helper
This is similar to uid_range_load_userns() but instead of reading the
uid_map off a process it reads it off a userns fd.
(Of course the kernel has no API for this right now, hence we fork off a
throw-away process which joins the user namespace, and then read off the
data from there.)
image-policy: add a new image_policy_intersect() call
This new call takes two image policy objects and generates an
"intersection" policy, i.e. only allows what is allowed by both. Or in
other words it conceptually implements a binary AND of the policy flags.
(Except that it's a bit harder, due to normalization, and underspecified
flags).
We can use this later for mountfsd: a client can specify a policy, and
mountfsd can specify another policy, and we'll then apply only what both
allow.
Note that a policy generated like this might be invalid. For example, if
one policy says root must exist and be verity or luks protected, and the
other policy says root must be absent, then the intersection is invalid,
since one policy only allows what the other prohibits and vice versa.
We'll return a clear error code in that case (ENAVAIL). (This is because
we simply don't allow encoding such impossible policies in an
ImagePolicy structure, for good reasons.)
This new call is like varlink_peek_fd() (i.e. gets an fd out of the
connection but leaving it also in there), and combines ith with
F_DUPFD_CLOEXEC to make a copy of it.
We previously already had varlink_dup_fd() which was a duplicating
version for pushing an fd *into* the connection. To reduce confusion,
let's rename that one varlink_push_dup_fd() to make the symmetry to
valrink_push_fd() clear so that we have no:
varlink_peer_push_fd() → put fd in without dup'ing
varlink_peer_push_dup_fd() → same with F_DUPFD_CLOEXEC
varlink_peer_peek_fd() → get fd out without dup'ing
varlink_peer_peek_dup_fd() → same with F_DUPFD_CLOEXEC
Since e56a8790a0 debugging test-execute fails has been a royal PITA, since
we ditch all potentially useful output from the test units (that, for
the most part, run `sh -x ...`). Let's improve the situation a bit by
setting EXEC_OUTPUT_NULL only when running the single test case that
needs it, and inheriting stdout otherwise.
For example, with a purposefully introduced error we get this output
with this patch:
exec-personality-x86-64.service: About to execute: sh -x -c "c=\$\$(uname -m); test \"\$\$c\" = \"foo_bar\""
Serializing sd-executor-state to memfd.
...
Personality: x86-64
LockPersonality: no
SystemCallErrorNumber: kill
++ uname -m
+ c=x86_64
+ test x86_64 = foo_bar
Received SIGCHLD from PID 1520588 (sh).
Child 1520588 (sh) died (code=exited, status=1/FAILURE)
exec-personality-x86-64.service: Child 1520588 belongs to exec-personality-x86-64.service.
exec-personality-x86-64.service: Main process exited, code=exited, status=1/FAILURE
exec-personality-x86-64.service: Failed with result 'exit-code'.
...
Exit Status: 1
src/test/test-execute.c:456:test_exec_personality: exec-personality-x86-64.service: can_unshare=yes: exit status 1, expected 0
(test-execute-root) terminated by signal ABRT.
Assertion 'r >= 0' failed at src/test/test-execute.c:1433, function prepare_ns(). Aborting.
Aborted
But without it, we'd miss the most important part:
exec-personality-x86-64.service: About to execute: sh -x -c "c=\$\$(uname -m); test \"\$\$c\" = \"foo_bar\""
Serializing sd-executor-state to memfd.
...
Personality: x86-64
LockPersonality: no
SystemCallErrorNumber: kill
Received SIGCHLD from PID 1521365 (sh).
Child 1521365 (sh) died (code=exited, status=1/FAILURE)
exec-personality-x86-64.service: Child 1521365 belongs to exec-personality-x86-64.service.
exec-personality-x86-64.service: Main process exited, code=exited, status=1/FAILURE
exec-personality-x86-64.service: Failed with result 'exit-code'.
...
Exit Status: 1
src/test/test-execute.c:456:test_exec_personality: exec-personality-x86-64.service: can_unshare=yes: exit status 1, expected 0
(test-execute-root) terminated by signal ABRT.
Assertion 'r >= 0' failed at src/test/test-execute.c:1433, function prepare_ns(). Aborting.
Aborted
Mike Yuan [Fri, 5 Apr 2024 10:21:50 +0000 (18:21 +0800)]
core/service: make service_set_main_pidref consume pidref
Currently, the memory management of service_set_main_pidref
is a bit odd. Normally we either invalidate the original
resource on caller's side after the call succeeds, or
just pass the ownership wholly. But service_set_main_pidref
take a pointer, and calls pidref_done() internally.
Let's just make it consume the passed pidref. This is more
straightforward.
On s390x both __s390__ and __s390x__ are defined, and with the original
order we'd go through the __s390__ branch and emit a warning:
[169/2118] Compiling C object src/shared/libsystemd-shared-256.a.p/base-filesystem.c.o
../src/shared/base-filesystem.c:136:11: note: ‘#pragma message: Please add an entry above specifying whether your architecture uses /lib64/, /lib32/, or no such links.’
136 | # pragma message "Please add an entry above specifying whether your architecture uses /lib64/, /lib32/, or no such links."
| ^~~~~~~
test: account for build dir being under one of the tmpfs-ed directories
If we're running test-execute from the build directory which is under
one of the tmpfs-ed directories (i.e. /root or /tmp), test-execute might
behave strangely, since in that case manager_new() pins the system
systemd-executor binary instead of the build dir one, which may lead to
a very confusing test fails (if there's enough difference between the
system and built sd-executor binary). Let's account for that and
bind-mount the build dir under the tmpfs-ed directory if necessary.
Debugging this was pain, since the child process didn't log anything
once we closed stdout/stderr (for obvious reasons). Let's fix both
issues by switching logging to kmsg once we close stdin/stdout/stderr,
and also by making the test work fine when there are some extra FDs in
the child's environment.
core: Serialize both pid and pidfd to keep downgrades working
Currently, when downgrading from a version with pidfd support to a
version without pidfd support, all information about running processes
is lost as the newer systemd will serialized pidfds which are not recognized
by the older systemd when deserializing.
To improve the situation, let's serialize both the pid and the pidfd.
This is safe because existing versions will either replace the first
deserialized pidref with the second one or discard the second one in
favor of the first one depending on the unit and field. Older versions
that don't support pidfd's will silently discard any fields that contain
a pidfd as those will try to parse the field as a pid and since a pidfd
field will start with '@', those versions will debug error log and ignore
the value.
To make sure we reuse the existing pidfd as much as possible, the pidfd
is serialized first. Both for scopes and service main pids, if the same
pid is seen multiple times, the first pidref is kept. So by serializing
the pidfd first we make sure the original pidfd is used instead of the
new one which is opened when deserializing the first pid field.
For other control units, older versions with pidfd support will discard
the first pidfd and replace it with a new pidfd from the second pid field.
This is a slight regression on downgrades, but we make sure it doesn't
happen for future versions (and older versions when this commit is
backported) by modifying the logic to only use the first successfully
deserialized pidref so that the raw pid without pidfd is discarded instead
of it replacing the existing pidfd.
meson: set -fno-ssa-phiopt when building bpf with gcc
There are bugs in the kernel verifier that cause legitimate code
to be rejected, disabling this optimization makes bpf programs
built with a new enough gcc work again.