[systemd-devel] systemd 255 released
systemd tag bot
donotreply-systemd-tag at refi64.com
Wed Dec 6 20:51:10 UTC 2023
🎆 A new, official systemd release has just 🎉 been 🎊 tagged 🍾. Please download the tarball here:
Changes since the previous release:
Announcements of Future Feature Removals and Incompatible Changes:
* Support for split-usr (/usr/ mounted separately during late boot,
instead of being mounted by the initrd before switching to the rootfs)
and unmerged-usr (parallel directories /bin/ and /usr/bin/, /lib/ and
/usr/lib/, …) has been removed. For more details, see:
* We intend to remove cgroup v1 support from a systemd release after
the end of 2023. If you run services that make explicit use of
cgroup v1 features (i.e. the "legacy hierarchy" with separate
hierarchies for each controller), please implement compatibility with
cgroup v2 (i.e. the "unified hierarchy") sooner rather than later.
Most of Linux userspace has been ported over already.
* Support for System V service scripts is now deprecated and will be
removed in a future release. Please make sure to update your software
*now* to include a native systemd unit file instead of a legacy
System V script to retain compatibility with future systemd releases.
* Support for the SystemdOptions EFI variable is deprecated.
'bootctl systemd-efi-options' will emit a warning when used. It seems
that this feature is little-used and it is better to use alternative
approaches like credentials and confexts. The plan is to drop support
altogether at a later point, but this might be revisited based on
* systemd-run's switch --expand-environment= which currently is disabled
by default when combined with --scope, will be changed in a future
release to be enabled by default.
* "systemctl switch-root" is now restricted to initrd transitions only.
Transitions between real systems should be done with
"systemctl soft-reboot" instead.
* The "ip=off" and "ip=none" kernel command line options interpreted by
systemd-network-generator will now result in IPv6RA + link-local
addressing being disabled, too. Previously DHCP was turned off, but
IPv6RA and IPv6 link-local addressing was left enabled.
* The NAMING_BRIDGE_MULTIFUNCTION_SLOT naming scheme has been deprecated
and is now disabled.
* SuspendMode=, HibernateState= and HybridSleepState= in the [Sleep]
section of systemd-sleep.conf are now deprecated and have no effect.
They did not (and could not) take any value other than the respective
default. HybridSleepMode= is also deprecated, and will now always use
the 'suspend' disk mode.
* The way services are spawned has been overhauled. Previously, a
process was forked that shared all of the manager's memory (via
copy-on-write) while doing all the required setup (e.g.: mount
namespaces, CGroup configuration, etc.) before exec'ing the target
executable. This was problematic for various reasons: several glibc
APIs were called that are not supposed to be used after a fork but
before an exec, copy-on-write meant that if either process (the
manager or the child) touched a memory page a copy was triggered, and
also the memory footprint of the child process was that of the
manager, but with the memory limits of the service. From this version
onward, the new process is spawned using CLONE_VM and CLONE_VFORK
semantics via posix_spawn(3), and it immediately execs a new internal
binary, systemd-executor, that receives the configuration to apply
via memfd, and sets up the process before exec'ing the target
executable. The systemd-executor binary is pinned by file descriptor
by each manager instance (system and users), and the reference is
updated on daemon-reexec - it is thus important to reexec all running
manager instances when the systemd-executor and/or libsystemd*
libraries are updated on the filesystem.
* Most of the internal process tracking is being changed to use PIDFDs
instead of PIDs when the kernel supports it, to improve robustness
* A new option SurviveFinalKillSignal= can be used to configure the
unit to be skipped in the final SIGTERM/SIGKILL spree on shutdown.
This is part of the required configuration to let a unit's processes
survive a soft-reboot operation.
* System extension images (sysext) can now set
EXTENSION_RELOAD_MANAGER=1 in their extension-release files to
automatically reload the service manager (PID 1) when
merging/refreshing/unmerging on boot. Generally, while this can be
used to ship services in system extension images it's recommended to
do that via portable services instead.
* The ExtensionImages= and ExtensionDirectories= options now support
* A new option NFTSet= provides a method for integrating dynamic cgroup
IDs into firewall rules with NFT sets. The benefit of using this
setting is to be able to use control group as a selector in firewall
rules easily and this in turn allows more fine grained filtering.
Also, NFT rules for cgroup matching use numeric cgroup IDs, which
change every time a service is restarted, making them hard to use in
* A new option CoredumpReceive= can be set for service and scope units,
together with Delegate=yes, to make systemd-coredump on the host
forward core files from processes crashing inside the delegated
CGroup subtree to systemd-coredump running in the container. This new
option is by default used by systemd-nspawn containers that use the
* A new ConditionSecurity=measured-uki option is now available, to ensure
a unit can only run when the system has been booted from a measured UKI.
* MemoryAvailable= now considers physical memory if there are no CGroup
memory limits set anywhere in the tree.
* The $USER environment variable is now always set for services, while
previously it was only set if User= was specified. A new option
SetLoginEnvironment= is now supported to determine whether to also set
$HOME, $LOGNAME, and $SHELL.
* Socket units now support a new pair of
PollLimitBurst=/PollLimitInterval= options to configure a limit on
how often polling events on the file descriptors backing this unit
will be considered within a time window.
* Scope units can now be created using PIDFDs instead of PIDs to select
the processes they should include.
* Sending SIGRTMIN+18 with 0x500 as sigqueue() value will now cause the
manager to dump the list of currently pending jobs.
* If the kernel supports MOVE_MOUNT_BENEATH, the systemctl and
machinectl bind and mount-image verbs will now cause the new mount to
replace the old mount (if any), instead of overmounting it.
* Units now have MemoryPeak, MemorySwapPeak, MemorySwapCurrent and
MemoryZSwapCurrent properties, which respectively contain the values
of the cgroup v2's memory.peak, memory.swap.peak, memory.swap.current
and memory.zswap.current properties. This information is also show in
"systemctl status" output, if available.
TPM2 Support + Disk Encryption & Authentication:
* systemd-cryptenroll now allows specifying a PCR bank and explicit hash
value in the --tpm2-pcrs= option.
* systemd-cryptenroll now allows specifying a TPM2 key handle (nv
index) to be used instead of the default SRK via the new
* systemd-cryptenroll now allows TPM2 enrollment using only a TPM2
public key (in TPM2B_PUBLIC format) – without access to the TPM2
device itself – which enables offline sealing of LUKS images for a
specific TPM2 chip, as long as the SRK public key is known. Pass the
public to the tool via the new --tpm2-device-key= switch.
* systemd-cryptsetup is now installed in /usr/bin/ and is no longer an
* The TPM2 Storage Root Key will now be set up, if not already present,
by a new systemd-tpm2-setup.service early boot service. The SRK will
be stored in PEM format and TPM2_PUBLIC format (the latter is useful
for systemd-cryptenroll --tpm2-device-key=, as mentioned above) for
easier access. A new "srk" verb has been added to systemd-analyze to
allow extracting it on demand if it is already set up.
* The internal systemd-pcrphase executable has been renamed to
* The systemd-pcrextend tool gained a new --pcr= switch to override
which PCR to measure into.
* systemd-pcrextend now exposes a Varlink interface at
io.systemd.PCRExtend that can be used to do measurements and event
logging on demand.
* TPM measurements are now also written to an event log at
/run/log/systemd/tpm2-measure.log, using a derivative of the TCG
Canonical Event Log format. Previously we'd only log them to the
journal, where they however were subject to rotation and similar.
* A new component "systemd-pcrlock" has been added that allows managing
local TPM2 PCR policies for PCRs 0-7 and similar, which are hard to
predict by the OS vendor because of the inherently local nature of
what measurements they contain, such as firmware versions of the
system and extension cards and suchlike. pcrlock can predict PCR
measurements ahead of time based on various inputs, such as the local
TPM2 event log, GPT partition tables, PE binaries, UKI kernels, and
various other things. It can then pre-calculate a TPM2 policy from
this, which it stores in an TPM2 NV index. TPM2 objects (such as disk
encryption keys) can be locked against this NV index, so that they
are locked against a specific combination of system firmware and
state. Alternatives for each component are supported to allowlist
multiple kernel versions or boot loader version simultaneously
without losing access to the disk encryption keys. The tool can also
be used to analyze and validate the local TPM2 event log.
systemd-cryptsetup, systemd-cryptenroll, systemd-repart have all been
updated to support such policies. There's currently no support for
locking the system's root disk against a pcrlock policy, this will be
added soon. Moreover, it is currently not possible to combine a
pcrlock policy with a signed PCR policy. This component is
experimental and its public interface is subject to change.
systemd-boot, systemd-stub, ukify, bootctl, kernel-install:
* bootctl will now show whether the system was booted from a UKI in its
* systemd-boot and systemd-stub now use different project keys in their
respective SBAT sections, so that they can be revoked individually if
* systemd-boot will no longer load unverified Devicetree blobs when UEFI
SecureBoot is enabled. For more details see:
* systemd-boot gained new hotkeys to reboot and power off the system
from the boot menu ("B" and "O"). If the "auto-poweroff" and
"auto-reboot" options in loader.conf are set these entries are also
shown as menu items (which is useful on devices lacking a regular
* systemd-boot gained a new configuration value "menu-disabled" for the
set-timeout option, to allow completely disabling the boot menu,
including the hotkey.
* systemd-boot will now measure the content of loader.conf in TPM2
* systemd-stub will now concatenate the content of all kernel
command-line addons before measuring them in TPM2 PCR 12, in a single
measurement, instead of measuring them individually.
* systemd-stub will now measure and load Devicetree Blob addons, which
are searched and loaded following the same model as the existing
kernel command-line addons.
* systemd-stub will now ignore unauthenticated kernel command line options
passed from systemd-boot when running inside Confidential VMs with UEFI
* systemd-stub will now load a Devicetree blob even if the firmware did
not load any beforehand (e.g.: for ACPI systems).
* ukify is no longer considered experimental, and now ships in /usr/bin/.
* ukify gained a new verb inspect to describe the sections of a UKI and
print the contents of the well-known sections.
* ukify gained a new verb genkey to generate a set of key pairs for
signing UKIs and their PCR data.
* The 90-loaderentry kernel-install hook now supports installing device
* kernel-install now supports the --json=, --root=, --image=, and
--image-policy= options for the inspect verb.
* kernel-install now supports new list and add-all verbs. The former
lists all installed kernel images (if those are available in
/usr/lib/modules/). The latter will install all the kernels it can
find to the ESP.
* A new option --copy-from= has been added that synthesizes partition
definitions from the given image, which are then applied by the
* A new option --copy-source= has been added, which can be used to specify
a directory to which CopyFiles= is considered relative to.
* New --make-ddi=confext, --make-ddi=sysext, and --make-ddi=portable
options have been added to make it easier to generate these types of
DDIs, without having to provide repart.d definitions for them.
* The dm-verity salt and UUID will now be derived from the specified
* New VerityDataBlockSizeBytes= and VerityHashBlockSizeBytes= can now be
configured in repart.d/ configuration files.
* A new Subvolumes= setting is now supported in repart.d/ configuration
files, to indicate which directories in the target partition should be
* A new --tpm2-device-key= option can be used to lock a disk against a
specific TPM2 public key. This matches the same switch the
systemd-cryptenroll tool now supports (see above).
* The journalctl --lines= parameter now accepts +N to show the oldest N
entries instead of the newest.
* journald now ensures that sealing happens once per epoch, and sets a
new compatibility flag to distinguish old journal files that were
created before this change, for backward compatibility.
* udev will now create symlinks to loopback block devices in the
/dev/disk/by-loop-ref/ directory that are based on the .lo_file_name
string field selected during allocation. The systemd-dissect tool and
the util-linux losetup command now supports a complementing new switch
--loop-ref= for selecting the string. This means a loopback block
device may now be allocated under a caller-chosen reference and can
subsequently be referenced without first having to look up the block
device name the caller ended up with.
* udev also creates symlinks to loopback block devices in the
/dev/disk/by-loop-inode/ directory based on the .st_dev/st_ino fields
of the inode attached to the loopback block device. This means that
attaching a file to a loopback device will implicitly make a handle
available to be found via that file's inode information.
* udevadm info gained support for JSON output via a new --json= flag, and
for filtering output using the same mechanism that udevadm trigger
* The predictable network interface naming logic is extended to include
the SR-IOV-R "representor" information in network interface names.
This feature was intended for v254, but even though the code was
merged, the part that actually enabled the feature was forgotten.
It is now enabled by default and is part of the new "v255" naming
* A new hwdb/rules file has been added that sets the
ID_NET_AUTO_LINK_LOCAL_ONLY=1 udev property on all network interfaces
that should usually only be configured with link-local addressing
(IPv4LL + IPv6LL), i.e. for PC-to-PC cables ("laplink") or
Thunderbolt networking. systemd-networkd and NetworkManager (soon)
will make use of this information to apply an appropriate network
configuration by default.
* The ID_NET_DRIVER property on network interfaces is now set
relatively early in the udev rule set so that other rules may rely on
its use. This is implemented in a new "net-driver" udev built-in.
* The "duid-only" option for DHCPv4 client's ClientIdentifier= setting
is now dropped, as it never worked, hence it should not be used by
* The 'prefixstable' ipv6 address generation mode now considers the SSID
when generating stable addresses, so that a different stable address
is used when roaming between wireless networks. If you already use
'prefixstable' addresses with wireless networks, the stable address
will be changed by the update.
* The DHCPv4 client gained a RapidCommit option, true by default, which
enables RFC4039 Rapid Commit behavior to obtain a lease in a
simplified 2-message exchange instead of the typical 4-message
exchange, if also supported by the DHCP server.
* The DHCPv4 client gained new InitialCongestionWindow= and
InitialAdvertisedReceiveWindow= options for route configurations.
* The DHCPv4 client gained a new RequestAddress= option that allows
to send a preferred IP address in the initial DHCPDISCOVER message.
* The DHCPv4 server and client gained support for IPv6-only mode
* The SendHostname= and Hostname= options are now available for the
DHCPv6 client, independently of the DHCPv4= option, so that these
configuration values can be set independently for each client.
* The DHCPv4 and DHCPv6 client state can now be queried via D-Bus,
including lease information.
* The DHCPv6 client can now be configured to use a custom DUID type.
* .network files gained a new IPv4ReversePathFilter= setting in the
[Network] section, to control sysctl's rp_filter setting.
* .network files gaiend a new HopLimit= setting in the [Route] section,
to configure a per-route hop limit.
* .network files gained a new TCPRetransmissionTimeoutSec= setting in
the [Route] section, to configure a per-route TCP retransmission
* A new directive NFTSet= provides a method for integrating network
configuration into firewall rules with NFT sets. The benefit of using
this setting is that static network configuration or dynamically
obtained network addresses can be used in firewall rules with the
indirection of NFT set types.
* The [IPv6AcceptRA] section supports the following new options:
UsePREF64=, UseHopLimit=, UseICMP6RateLimit=, and NFTSet=.
* The [IPv6SendRA] section supports the following new options:
RetransmitSec=, HopLimit=, HomeAgent=, HomeAgentLifetimeSec=, and
* A new [IPv6PREF64Prefix] set of options, containing Prefix= and
LifetimeSec=, has been introduced to append pref64 options in router
* The network generator now configures the interfaces with only
link-local addressing if "ip=link-local" is specified on the kernel
* The prefix of the configuration files generated by the network
generator from the kernel command line is now prefixed with '70-',
to make them have higher precedence over the default configuration
* Added a new -Ddefault-network=BOOL meson option, that causes more
.network files to be installed as enabled by default. These configuration
files will which match generic setups, e.g. 89-ethernet.network matches
all Ethernet interfaces and enables both DHCPv4 and DHCPv6 clients.
* If a ID_NET_MANAGED_BY= udev property is set on a network device and
it is any other string than "io.systemd.Network" then networkd will
not manage this device. This may be used to allow multiple network
management services to run in parallel and assign ownership of
specific devices explicitly. NetworkManager will soon implement a
* systemctl is-failed now checks the system state if no unit is
* systemctl will now automatically soft-reboot if a new root file system
is found under /run/nextroot/ when a reboot operation is invoked.
* Wall messages now work even when utmp support is disabled, using
systemd-logind to query the necessary information.
* systemd-logind now sends a new PrepareForShutdownWithMetadata D-Bus
signal before shutdown/reboot/soft-reboot that includes additional
information compared to the PrepareForShutdown signal. Currently the
additional information is the type of operation that is about to be
Hibernation & Suspend:
* The kernel and OS versions will no longer be checked on resume from
* Hibernation into swap files backed by btrfs are now
supported. (Previously this was supported only for other file
* A new systemd-vmspawn tool has been added, that aims to provide for VMs
the same interfaces and functionality that systemd-nspawn provides for
containers. For now it supports QEMU as a backend, and exposes some of
its options to the user. This component is experimental and its public
interface is subject to change.
* "systemd-analyze plot" has gained tooltips on each unit name with
related-unit information in its svg output, such as Before=,
Requires=, and similar properties.
* A new varlinkctl tool has been added to allow interfacing with
Varlink services, and introspection has been added to all such
services. This component is experimental and its public interface is
subject to change.
* systemd-sysext and systemd-confext now expose a Varlink service
* portable services now accept confexts as extensions.
* systemd-sysupdate now accepts directories in the MatchPattern= option.
* systemd-run will now output the invocation ID of the launched
transient unit and its peak memory usage.
* systemd-analyze, systemd-tmpfiles, systemd-sysusers, systemd-sysctl,
and systemd-binfmt gained a new --tldr option that can be used instead
of --cat-config to suppress uninteresting configuration lines, such as
comments and whitespace.
* resolvectl gained a new "show-server-state" command that shows
current statistics of the resolver. This is backed by a new
DumpStatistics() Varlink method provided by systemd-resolved.
* systemd-timesyncd will now emit a D-Bus signal when the LinkNTPServers
* vconsole now supports KEYMAP=@kernel for preserving the kernel keymap
* seccomp now supports the LoongArch64 architecture.
* seccomp may now be enabled for services running as a non-root User=
* systemd-id128 now supports a new -P option to show only values. The
combination of -P and --app options is also supported.
* A new pam_systemd_loadkey.so PAM module is now available, which will
automatically fetch the passphrase used by cryptsetup to unlock the
root file system and set it as the PAM authtok. This enables, among
other things, configuring auto-unlock of the GNOME Keyring / KDE
Wallet when autologin is configured.
* Many meson options now use the 'feature' type, which means they
take enabled/disabled/auto as values.
* A new meson option -Dconfigfiledir= can be used to change where
configuration files with default values are installed to.
* Options and verbs in man pages are now tagged with the version they
were first introduced in.
* A new component "systemd-storagetm" has been added, which exposes all
local block devices as NVMe-TCP devices, fully automatically. It's
hooked into a new target unit storage-target-mode.target that is
suppsoed to be booted into via
rd.systemd.unit=storage-target-mode.target on the kernel command
line. This is intended to be used for installers and debugging to
quickly get access to the local disk. It's inspired by MacOS "target
disk mode". This component is experimental and its public interface is
subject to change.
* A new component "systemd-bsod" has been added, which can show logged
error messages full screen, if they have a log level of LOG_EMERG log
level. This component is experimental and its public interface is
subject to change.
* The systemd-dissect tool's --with command will now set the
$SYSTEMD_DISSECT_DEVICE environment variable to the block device it
operates on for the invoked process.
* The systemd-mount tool gained a new --tmpfs switch for mounting a new
'tmpfs' instance. This is useful since it does so via .mount units
and thus can be executed remotely or in containers.
* The various tools in systemd that take "verbs" (such as systemctl,
loginctl, machinectl, …) now will suggest a close verb name in case
the user specified an unrecognized one.
* libsystemd now exports a new function sd_id128_get_app_specific()
that generates "app-specific" 128bit IDs from any ID. It's similar to
sd_id128_get_boot_app_specific() but takes the ID to base calculation
on as input. This new functionality is also exposed in the
"systemd-id128" tool where you can now combine --app= with `show`.
* All tools that parse timestamps now can also parse RFC3339 style
timestamps that include the "T" and Z" characters.
* New documentation has been added:
* The codebase now recognizes the suffix .confext.raw and .sysext.raw
as alternative to the .raw suffix generally accepted for DDIs. It is
recommended to name configuration extensions and system extensions
with such suffixes, to indicate their purpose in the name.
* The sd-device API gained a new function
sd_device_enumerator_add_match_property_required() which allows
configuring matches on properties that are strictly required. This is
different from the existing sd_device_enumerator_add_match_property()
matches of which one one needs to apply.
* The MAC address the veth side of an nspawn container shall get
assigned may now be controlled via the $SYSTEMD_NSPAWN_NETWORK_MAC
* The libiptc dependency is now implemented via dlopen(), so that tools
such as networkd and nspawn no longer have a hard dependency on the
shared library when compiled with support for libiptc.
* New rpm macros have been added: %systemd_user_daemon_reexec does
daemon-reexec for all user managers, and %systemd_postun_with_reload
and %systemd_user_postun_with_reload do a reload for system and user
units on upgrades.
* coredumpctl now propagates SIGTERM to the debugger process.
Contributions from: 김인수, Abderrahim Kitouni, Adam Goldman,
Adam Williamson, Alexandre Peixoto Ferreira, Alex Hudspith,
Alvin Alvarado, André Paiusco, Antonio Alvarez Feijoo,
Anton Lundin, Arian van Putten, Arseny Maslennikov, Arthur Shau,
Balázs Úr, beh_10257, Benjamin Peterson, Bertrand Jacquin,
Brian Norris, Charles Lee, Cheng-Chia Tseng, Chris Patterson,
Christian Hergert, Christian Hesse, Christian Kirbach,
Clayton Craft, commondservice, cunshunxia, Curtis Klein, cvlc12,
Daan De Meyer, Daniele Medri, Daniel P. Berrangé, Daniel Rusek,
Daniel Thompson, Dan Nicholson, Dan Streetman, David Rheinsberg,
David Santamaría Rogado, David Tardon, dependabot[bot],
Diego Viola, Dmitry V. Levin, Emanuele Giuseppe Esposito,
Emil Renner Berthing, Emil Velikov, Etienne Dechamps, Fabian Vogt,
felixdoerre, Felix Dörre, Florian Schmaus, Franck Bui,
Frantisek Sumsal, G2-Games, Gioele Barabucci, Hugo Carvalho,
huyubiao, Iago López Galeiras, IllusionMan1212, Jade Lovelace,
janana, Jan Janssen, Jan Kuparinen, Jan Macku, Jeremy Fleischman,
Jin Liu, jjimbo137, Joerg Behrmann, Johannes Segitz, Jordan Rome,
Jordan Williams, Julien Malka, Juno Computers, Khem Raj, khm,
Kingbom Dou, Kiran Vemula, Krzesimir Nowak, Laszlo Gombos,
Lennart Poettering, linuxlion, Luca Boccassi, Lucas Adriano Salles,
Lukas, Lukáš Nykrýn, Maanya Goenka, Maarten, Malte Poll,
Marc Pervaz Boocha, Martin Beneš, Martin Joerg, Martin Wilck,
Mathieu Tortuyaux, Matthias Schiffer, Maxim Mikityanskiy,
Max Kellermann, Michael A Cassaniti, Michael Biebl, Michael Kuhn,
Michael Vasseur, Michal Koutný, Michal Sekletár, Mike Yuan,
Milton D. Miller II, mordner, msizanoen, NAHO, Nandakumar Raghavan,
Neil Wilson, Nick Rosbrook, Nils K, NRK, Oğuz Ersen,
Omojola Joshua, onenowy, Paul Meyer, Paymon MARANDI, pelaufer,
Peter Hutterer, PhylLu, Pierre GRASSER, Piotr Drąg, Priit Laes,
Rahil Bhimjiani, Raito Bezarius, Raul Cheleguini, Reto Schneider,
Richard Maw, Robby Red, RoepLuke, Roland Hieber, Roland Singer,
Ronan Pigott, Sam James, Sam Leonard, Sergey A, Susant Sahani,
Sven Joachim, Tad Fisher, Takashi Sakamoto, Thorsten Kukuk, Tj,
Tomasz Świątek, Topi Miettinen, Valentin David,
Valentin Lefebvre, Victor Westerhuis, Vincent Haupert,
Vishal Chillara Srinivas, Vito Caputo, Warren, Weblate,
Xiaotian Wu, xinpeng wang, Yaron Shahrabani, Yo-Jung Lin,
Yu Watanabe, Zbigniew Jędrzejewski-Szmek, zeroskyx,
Дамјан Георгиевски, наб
— Edinburgh, 2023-12-06
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