First of all, FD store propagation is enabled between manager instances,
and nspawn instances, via LISTEN_FDS and sd_notify. These can be nested
arbitrarily deeply all the way up to the system manager, and on restart
will be propagated all the way down to the origin. The FDs payload of an
nspawn container running as a user unit will be preserved, all the way
up to the system manager, and then down again.
The kernel Live Update Orchestrator (LUO) exposes /dev/liveupdate, which
lets userspace hand a set of "preservable" kernel objects to the new
kernel across a kexec-based reboot. For now it only supports memfds,
with more object types (virtio devices, etc.) expected to be added
later.
This is a natural fit for systemd's FD Store feature: services hand
memfds (containing serialized state or other service data) to PID 1 via
FDSTORE=1 sd_notify() messages, and get them back on their next start.
Today this works across service restarts, soft reboots and initrd→rootfs
transitions. With LUO, this series extends the same mechanism to work
across kexec too. The nesting preservation of FD stores thus now is
extended across kexec.
All preservable fds are collected into a single LUO session named
"systemd". Each fd is uploaded with an index (token). Token 0 is
reserved for a "mapping" memfd, which carries a JSON object describing
how to dispatch the other tokens back to units on the next boot.
Unit names are used as the unit identifier, as they are stable across
daemon-reexec, switch-root and kexec. token refers to the LUO index
assigned to the object in the session.
On shutdown for MANAGER_KEXEC, just before manager_free(), systemd walks
all services and serializes their persistent fd store contents (fds +
FDNAMEs + cgroup paths) into a JSON memfd. The fds themselves are
gathered into an FDSet. The fdset and the serialization memfd are passed
to systemd-shutdown via the SYSTEMD_LUO_SERIALIZE_FD environment
variable providing the fd number, so the actual LUO session creation and
ioctls happen as the very last step before kexec.
On boot, manager_luo_restore_fd_stores() opens /dev/liveupdate, tries to
retrieve the "systemd" session, reads the mapping memfd, then for each
entry retrieves the fd from the session and attempts to attach it to the
matching unit's fd store.
Because the initrd-stage PID 1 runs before the real rootfs units are
loaded, fds whose target unit is not (yet) known are not dropped: they
are stashed in a new luo_held_fds hashmap keyed by cgroup path. They are
re-tried in two places: after deserialization, and from unit_load(), so
fds land in the correct fd store as soon as the owning unit is parsed,
allowing units to be plugged in at runtime.
Non-kexec shutdown paths are unaffected: if MANAGER_KEXEC is not the
final objective, no serialization file is produced and no LUO session is
ever created. Likewise if /dev/liveupdate does not exist, nothing
happens.
The LUO session creation is performed by systemd-shutdown, rather than
by PID 1, deliberately: it is the last point where we can be sure all
other processes have already been killed, so nothing else can race us
into creating (or worse, hijacking) the "systemd" session.
/dev/liveupdate is a singleton and session names are global. In
addition, any kernel-visible side effects of preserving objects (memory
pinning, etc.) are delayed until the absolute last moment, minimizing
the window in which they could affect the running system. There is no
behaviour change for shutdown paths other than kexec, or for kexec when
systemd didn't hand over a serialization fd (e.g. because no service had
any fds stored, or because LUO wasn't supported at serialization time).
Finally, since LUO sessions cannot be nested under other sessions,
third-party sessions need to be handled explicitly and held open in the
shutdown binary alongside our own internal session, to allow services to
create and preserve their own sessions. The requirement comes from VMMs
that wish to preserve VM state across kexec: some file descriptors (e.g.
KVM's vmfd from the KVM_CREATE_VM ioctl) cannot be transferred between
processes via SCM_RIGHTS, so they cannot be stashed in the FD Store
directly. Additionally, some file descriptors must be handled
all-or-nothing, again tied to KVM, where a VM and its associated devices
are one indivisible group.
https://docs.kernel.org/userspace-api/liveupdate.htmlhttps://docs.kernel.org/core-api/liveupdate.htmlhttps://docs.kernel.org/admin-guide/mm/kho.html
LUO sessions cannot be nested under other sessions. This means we need
to handle them explicitly, and held them open in the shutdown binary
like we do with our own internal session, to allow services to create
their own.
The requirement to support third party sessions comes from VMMs that
wish to preserve VM(s) state(s) across kexec, as some file descriptors
(KVM's vmfd from the KVM_CREATE_VM ioctl) cannot be transfered between
processes via SCM_RIGHTS, so they cannot be stashed in the FD Store
directly. Also some file descriptors have to be handled all together or
not at all, again to do with KVM and devices that are all part of the
same vm.
Wires up the systemd-shutdown side of the kexec-via-LUO fd store preservation.
When rebooting via kexec, systemd builds a JSON description of the fd
stores of all loaded services and passes it to systemd-shutdown through
the SYSTEMD_LUO_SERIALIZE_FD environment variable. The FDs themselves
come in as part of the normal shutdown FDSet. systemd-shutdown's job is
then, at the very last moment before invoking the kexec syscall, to
move that state into a kernel LUO session so it survives the reboot.
Doing the LUO session creation here, rather than in PID 1, is
deliberate:
* It's the last point where we can be sure all other processes have
already been killed, so nothing else can race us into creating (or
worse, hijacking) the "systemd" session, as /dev/liveupdate is a
singleton and a session name is global.
* Any kernel-visible side effects of preserving objects (memory
pinning etc.) are delayed until the absolute last moment, minimizing
the window in which they could affect the running system
No behaviour change for shutdown paths other than kexec, or for kexec
when systemd didn't hand over a serialization fd (e.g. because no
service had any fds stored, or because LUO wasn't supported at
serialization time).
The kernel Live Update Orchestrator (LUO) exposes /dev/liveupdate, which
allows userspace to hand a set of "preservable" kernel objects to the
new kernel across a kexec-based reboot. For now it only supports memfds,
with more object types (virtio devices, etc.) expected to be added later.
This is a natural fit for systemd's FD Store feature: services hand
memfds (containing serialized state or other service data) to PID 1 via
FDSTORE=1 sd_notify() messages, and get them back on their next start.
Today this works across service restarts, soft reboots and
initrd→rootfs transitions. With LUO we can extend the same mechanism to
work across kexec, too.
The protocol on the PID 1 side works roughly as follows:
* All preservable fds are collected into a single LUO session named
"systemd". Each FD gets uploaded with a token. Token 0 in that session
is reserved for a "mapping" memfd, which carries a JSON object
describing how to dispatch the other tokens back to units on the next
boot:
{
"foo.service": [
{ "type": "fd", "name": "stateA", "token": 1 },
{ "type": "fd", "name": "stateB", "token": 2 }
],
...
}
unit IDs are used as the unit identifier, as they're stable
across daemon-reexec, switch-root and kexec. token refers to the
LUO token assigned to the object in the session.
* On shutdown for MANAGER_KEXEC, just before manager_free(), systemd
walks all services and serializes their persistent fd store contents
(fds + FDNAMEs + unit IDs) into a JSON memfd. The FDs themselves are
gathered into a FDSet to be kept around. The fdset and the
serialization memfd are passed to systemd-shutdown via the
SYSTEMD_LUO_SERIALIZE_FD environment variable providing the fd number,
so the actual LUO session creation and ioctls can happen as the very
last step before kexec (shutdown implementation is the next commit).
* On boot, manager_luo_restore_fd_stores() opens /dev/liveupdate,
tries to retrieve the "systemd" session, reads the mapping memfd,
then for each entry retrieves the fd from the session and attempts
to attach it to the matching unit's fd store.
* The FDs are injected in the appropriate unit's FD stores using the
same mechanism as the LISTEN_FDS propagation that was set up earlier.
Non-kexec shutdown paths are unaffected: if MANAGER_KEXEC is not the
final objective, no serialization file is produced and no LUO session
is ever created. Likewise if /dev/liveupdate does not exist, nothing
happens.
When there is a NOTIFY_SOCKET, and FDs are received from the
payload following the FD Store protocol, forward them up the
chain to the service manager that is managing nspawn.
This allows FD Store persistence across container restarts,
and can chain up for user managers as well to survive restarting
those, or reexecs, and in the future reboots too via LUO.
Add a new test case to exercise the PID1 -> user session -> nspawn -> payload
chain.
In order to allow FD Stores of user units to survive a user
session restart, propagate FDs received via the protocol up one
level from user to system manager via sd_notify.
And the other way around, propagate them down via LISTEN_FDS
tagging them with the unit name so that the child manager can
inject them in the appropriate unit.
Ensure units that are dead or not loaded can get FDs added to
their stores, and that they are correctly propagated once the
unit is started or loaded. When the unit is not loaded we don't
know what the FD max limit is, so simply increase it for each FD
injected, and then when the unit is realised prune it down to
match the unit's now available config in case the limit is lower
than the number of FDs in the store.
Each FD sent up or down is assigned a monotonic index, and the manager
also sends a JSON map that associates the index with the original
unit and FDNAME:
{
"unit-name.service": [
{ "name": "fdname1", "index": 1 },
{ "name": "fdname2", "index": 2 }
],
...
}
This allows the manager to assign back the FDs to the appropriate
unit using the appropriate name, given the FDNAMEs are not unique.
This PR adds some more properties to the io.systemd.Unit.StartTransient
varlink interface: WorkingDirectory, Environment and
SetCredential{,Encrypted}. Its also hopefully a useful starting point to
establish a pattern to add even more.
We want to reopen the console used for logging when running as PID1, but
also when running a user manager (c.f. 48a601fe5d
and 2a646b1d62). But this can cause
problems when the binary is invoked directly, e.g. to print --help.
E.g. if we ignore SIGPIPE, we'd remain running briefly after
'/usr/lib/systemd/systemd --help | head -n1'.
Previusly, the getopt machinery would print to stderr unconditionally.
But after the rework of option parsing, which means that we use the
log_* functions to repor errors, the test that checks if we print errors
to stderr started failing.
So let's skip some more of the setup if !invoked_by_systemd().
This function is used in a quite a few places and it calls getenv and
does a bit of parsing, so let's try to speed this up.
Also, mark it _const_. With the caching, it now always returns the same
result, so we can tell the compiler to eliminate subsequent invocations.
It'd be nice if we could not repeat the information about the option
list a second time. But I don't see a nice way to do this, since
(by design) with the macro approach, the macros must be intertwined
with the parse_argv() code. But that code in turn refers to a bunch
of variables, so lifting out the function is not immediately possible.
So I think it's best to keep the existing approach where we provide
a list of options, without additional context, and skip them using
a custom routine.
099663ff8c added "support" for
-b/-s/-z ARG with a comment of
> /* Just to eat away the sysvinit kernel cmdline args without getopt()
> * error messages that we'll parse in parse_proc_cmdline_word() or
> * ignore. */
And for PID1 those was valid. But when not running as PID1, those
options would be parsed as valid but then help() would immediately
return -EINVAL:
$ build-old/systemd -b; echo $?
1
At the same time, when running as PID1, if we encounter an error,
we shouldn't opine about the rest of the command line. So continuing
with the loop and the checks after the loop were iffy.
Later, cd57038a30 made a big refactoring,
and the 'break' (i.e. continuation of the loop) was changed to 'return 0',
making things even more confusing, since now we'd just silently stop in
the middle of the command line if -b/-s/-z were encountered.
So be more careful: when running as PID1, stop parsing on error
and return from the function. We didn't parse the full command line,
so the later checks are not useful. Silently ignore -b/-s/-z.
When not running as PID1, explicitly say that -b/-s/-z are not
supported, and propogate the error if parsing fails, e.g. with
an unknown option.
parse_argv() uses FOREACH_OPTION (not _OR_RETURN) so we can preserve the
existing PID 1 tolerance: an unknown option, or one of the sysvinit-style
-b/-s/-z catch-alls, returns 0 instead of -EINVAL when getpid_cached() == 1.
The docs documented --crash-vt=, but the code implemented "crash-chvt",
as introduced in b9e74c3994.
The output from --help is now modified to match code.
getopt-defs.h is intentionally left in place since
proc_cmdline_filter_pid1_args() in src/basic/proc-cmdline.c still uses
its COMMON_/SYSTEMD_/SHUTDOWN_GETOPT_* macros to walk the kernel
command line.
Previously, opterr=0 was used to suppress error messages about option
parsing in PID1. They are now logged at debug level (if debug logging
is enabled.)
Co-developed-by: Claude Opus 4.7 <noreply@anthropic.com>
Add exec_command_status_build_json() and exec_command_status_list_build_json() to varlink-common, alongside exec_command_build_json() and exec_command_list_build_json(). The status list function is the runtime counterpart of the command list function — the two arrays are positionally aligned so index N in the status array corresponds to index N in the command array. Commands that have not yet run produce null entries to preserve alignment.
Add the ExecCommandStatus varlink struct type to varlink-idl-common next to ExecCommand. It contains PID, timestamps, and mutually exclusive ExitStatus (int, for normal exit) / ExitSignal (string, for signal kill).
The cdn mirror is preferred by SUSE for clouds/CIs. There have been issues with some
mirrors, which fail to download from GHA quite often lately, so hopefully this will
make it reliable again.
This was missing in the CurrentSymlink= creation path, and leads to
partially-broken update installs.
Signed-off-by: Aleksa Sarai <aleksa@amutable.com>
When the periodic RA timer fires, any error returned by sendmsg()
currently propagates up through sd_radv_send() into radv_timeout(),
which then calls sd_radv_stop(). The RA engine is never started again
until the next carrier transition.
On an 802.3ad bond there is a window right after carrier-up where the
link is administratively up but no aggregator has been selected yet, so
sendmsg() returns ENOBUFS. If the very first RA after a flap lands in
that window, radv stops permanently and all clients lose their SLAAC
addresses, on-link/PD prefixes, and default router once the previously
advertised lifetimes expire, while IPv4 keeps working, leading to a very
confusing situation with v4 up and v6 down.
Handle this the same way solicited RAs already do (see
radv_process_packet()): log the failure and reschedule the timer instead
of giving up. ra_sent is left untouched on failure so we stay in the
fast initial-advertisement regime until a send actually succeeds.
link_radv_enabled() and link_ndisc_enabled() use
link_ipv6ll_enabled_harder(), which considers a static fe80:: address
in [Address] sufficient to run radv/ndisc even when LinkLocalAddressing=
(or IPv6LinkLocalAddressGenerationMode=none, which network_verify()
folds into the same flag) disables the kernel-generated link-local.
network_adjust_radv()/ndisc()/dhcp() however only check the raw
link_local flag and zero router_prefix_delegation / ndisc / dhcp&IPV6
at parse time, so the runtime gate never gets a chance to fire.
Factor the static-LL lookup out of link_ipv6ll_enabled_harder() into a
Network-level helper and use it in the three network_adjust_*()
functions, bringing parse-time and runtime behaviour in line.
The hidden-from-help options (--crash-reboot, --service-watchdogs,
--deserialize, --switched-root, --machine-id, -D, -b/-s/-z, ?)
move to the bottom. The 'b'/'s'/'z' → '?' fall-through is preserved.
Co-developed-by: Claude Opus 4.7 <noreply@anthropic.com>
Device enumeration may encounter transient errors such as ENXIO when devices
appear or disappear concurrently. These conditions represent expected "device absent"
races and should be treated uniformly across the enumeration logic.
This change replaces the ENODEV-specific check with ERRNO_IS_NEG_DEVICE_ABSENT(),
ensuring that all expected disappearance conditions are handled consistently.
Unexpected errors are still propagated, while expected races are ignored without
aborting the enumeration.
I had those prepared before but I didn't submit them because the
automatic layout didn't work well. In two cases now the sync of widths
between verbs and options is disabled and one case is left with the
automatic alignment. I think it'd good enough to merge.
Move the existing (partial) service context builder from varlink-unit.c into its own varlink-service.c file, following the pattern established by other unit type context builders (varlink-path.c, varlink-scope.c, etc.). No functional change.
Checking for pefile required that module to be made available for the
Python used to build systemd, even though it's only used at runtime,
potentially via a different Python installation.
Furthermore, Meson's Python module doesn't do the right thing when cross
compiling and looking up a Python for the host system, so this would end
up uselessly checking whether the build Python had the pefile module,
which is not needed. Even if it were made to check the host Python using
find_program, it still relies on being able to run its Python, which in
a cross scenario it probably wouldn't be able to do.
All in all, this check does more harm than good, and prevents building
ukify in valid configurations, so remove it.
Implement support for the --json= flag in the info subcommand
(issue #38844). Previously, coredumpctl info always produced
human-readable text output regardless of --json=.
Add a CoredumpFields struct that holds all journal fields extracted
for a coredump entry, along with coredump_fields_done() to release
member resources and coredump_fields_load() to populate the struct
from a journal entry. Both print_info() and the new print_info_json()
use this shared loader, eliminating the duplicate RETRIEVE loop.
print_info_json() builds a JSON object with the same fields shown by
print_info(). Missing fields are omitted via SD_JSON_BUILD_PAIR_CONDITION,
matching the tolerant behavior of print_info() rather than skipping the
entry entirely. Signal/Reason handling mirrors print_info(): normal
coredumps (MESSAGE_ID == SD_MESSAGE_COREDUMP_STR) emit a numeric Signal
field; non-normal entries (kernel oops, etc.) emit a Reason field with
the raw text from COREDUMP_SIGNAL.
Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
When the kernel hands the command line to PID 1, any KEY=VALUE assignment
whose KEY does not contain a '.' is exported as an environment variable
(with '-' replaced by '_') rather than passed as an argument. Mimic the
same split in --boot mode so kernel-cmdline-style arguments passed after
the container path behave as they would on a real boot.
When running test_xopenat_auto_rw_ro under a non-root user with the
CAP_DAC_OVERRIDE capability, the test currently fails.
As the comment already says, root bypasses mode bits via CAP_DAC_OVERRIDE so
let's check for that instead of the effective user ID.
Signed-off-by: Emanuele Rocca <emanuele.rocca@arm.com>
As pointed out in review, parse_path_argument can fail for non-oom reasons.
But the function already logs, so the correct thing to do is to just
propagate the error.
The conversion doesn't work great, because some of the verbs take many
arguments and the first column is extermely wide. So similarly to
kernel-install, I dropped the sync of column widths. This allows the
help for options to use most of the available space.
-C/--capsule is now documented, fixup for
00431b2b66.
Verb functions are renamed to match verb names.
The missing first param is added to the synopsis of "wait".
It now matches the man page.
Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
The verb synopses are long, so they got broken up:
===============================================================================
> localectl [OPTIONS…] COMMAND …
Query or change system locale and keyboard settings.
Commands:
[status] Show current locale settings
set-locale LOCALE... Set system locale
list-locales Show known locales
set-keymap MAP [MAP] Set console and X11 keyboard mappings
list-keymaps Show known virtual console keyboard mappings
set-x11-keymap LAYOUT [MODEL Set X11 and console keyboard mappings
[VARIANT [OPTIONS]]]
list-x11-keymap-models Show known X11 keyboard mapping models
list-x11-keymap-layouts Show known X11 keyboard mapping layouts
list-x11-keymap-variants Show known X11 keyboard mapping variants
[LAYOUT]
list-x11-keymap-options Show known X11 keyboard mapping options
Options:
-h --help Show this help
--version Show package version
-l --full Do not ellipsize output
--no-pager Do not start a pager
--no-ask-password Do not prompt for password
-H --host=[USER@]HOST Operate on remote host
-M --machine=CONTAINER Operate on local container
--no-convert Don't convert keyboard mappings
See the localectl(1) man page for details.
===============================================================================
But I think this is OK. Everything is readable. On a more normal terminal,
everything fits nicely.
Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
The verb synopses are very long because of the many parameters.
Previously were shown without help and occupied all available columns.
With the autogenerated help format, this doesn't work great. So the
verbs and options tables are not synced, so that help for options can
use more columns. I think in this case this is better than the
alternatives.
Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
наб
Luca Boccassi
Daan De Meyer
Yu Watanabe
Zbigniew Jędrzejewski-Szmek
Ivan Kruglov
Michal Sekletar
Aleksa Sarai
Philip Withnall
r-vdp
Lennart Poettering
我超厉害
noxiouz
Frantisek Sumsal
Emanuele Rocca