Currently in mkosi and ukify we use sbsigntools to do secure boot
signing. This has multiple issues:
- sbsigntools is practically unmaintained, sbvarsign is completely
broken with the latest gnu-efi when built without -fshort-wchar and
upstream has completely ignored my bug report about this.
- sbsigntools only supports openssl engines and not the new providers
API.
- sbsigntools doesn't allow us to cache hardware token pins in the
kernel keyring like we do nowadays when we sign stuff ourselves in
systemd-repart or systemd-measure
There are alternative tools like sbctl and pesign but these do not
support caching hardware token pins in the kernel keyring either.
To get around the issues with sbsigntools, let's introduce our own
tool systemd-sbsign to do secure boot signing. This allows us to
take advantage of our own openssl infra so that hardware token pins
are cached in the kernel keyring as expected and we get openssl
provider support as well.
The section headers used quotes as if the strings were some constants. But
AFAICT, those are just normal plain-text titles. Also lowercase them, because
this is almost like a table and it's easier to read without capitalization.
We used both, in fact "Devicetree" was more common. But we have a general rule
that we capitalize all words in names and also we have a DeviceTree=
configuration setting, which we cannot change. If we use two different
spelllings, this will make it harder for people to use the correct one in
config files. So use the "DeviceTree" spelling everywhere.
Since v256 we completely fail to boot if v1 is configured. Fedora 41 was just
released with v256.7 and this is probably the first major exposure of users to
this code. It turns out not work very well. Fedora switched to v2 as default in
F31 (2019) and at that time some people added configuration to use v1 either
because of Docker or for other reasons. But it's been long enough ago that
people don't remember this and are now very unhappy when the system refuses to
boot after an upgrade.
Refusing to boot is also unnecessarilly punishing to users. For machines that
are used remotely, this could mean somebody needs to physically access the
machine. For other users, the machine might be the only way to access the net
and help, and people might not know how to set kernel parameters without some
docs. And because this is in systemd, after an upgrade all boot choices are
affected, and it's not possible to e.g. select an older kernel for boot. And
crashing the machine doesn't really serve our goal either: we were giving a
hint how to continue using v1 and nothing else.
If the new override is configured, warn and immediately boot to v1.
If v1 is configured w/o the override, warn and wait 30 s and boot to v2.
Also give a hint how to switch to v2.
https://bugzilla.redhat.com/show_bug.cgi?id=2323323https://bugzilla.redhat.com/show_bug.cgi?id=2323345https://bugzilla.redhat.com/show_bug.cgi?id=2322467https://www.reddit.com/r/Fedora/comments/1gfcyw9/refusing_to_run_under_cgroup_01_sy_specified_on/
The advice is to set systemd.unified_cgroup_hierarchy=1 (instead of removing
systemd.unified_cgroup_hierarchy=0). I think this is easier to convey. Users
who are understand what is going on can just remove the option instead.
The caching is dropped in cg_is_legacy_wanted(). It turns out that the
order in which those functions are called during early setup is very fragile.
If cg_is_legacy_wanted() is called before we have set up the v2 hierarchy,
we incorrectly cache a true answer. The function is called just a handful
of times at most, so we don't really need to cache the response.
The text added for .dtbauto/.hwids was very hard to grok. This rewords it to be
proper English. No semantic changes are intended.
When updating this, I noticed that the interaction of multi-profile UKIs and
dtb autoselection is very unclear, a FIXME is added.
Currently in mkosi and ukify we use sbsigntools to do secure boot
signing. This has multiple issues:
- sbsigntools is practically unmaintained, sbvarsign is completely
broken with the latest gnu-efi when built without -fshort-wchar and
upstream has completely ignored my bug report about this.
- sbsigntools only supports openssl engines and not the new providers
API.
- sbsigntools doesn't allow us to cache hardware token pins in the
kernel keyring like we do nowadays when we sign stuff ourselves in
systemd-repart or systemd-measure
There are alternative tools like sbctl and pesign but these do not
support caching hardware token pins in the kernel keyring either.
To get around the issues with sbsigntools, let's introduce our own
tool systemd-sbsign to do secure boot signing. This allows us to
take advantage of our own openssl infra so that hardware token pins
are cached in the kernel keyring as expected and we get openssl
provider support as well.
Let's systematically make sure that we link up the D-Bus interfaces from
the daemon man pages once in prose and once in short form at the bottom
("See Also"), for all daemons.
Also, add reverse links at the bottom of the D-Bus API docs.
Fixes: #34996
We have this in a similar fashion for the other APIs libsystemd
provides. Add the same for sd-varlink. There isn't too much on it for
now, but at least it's a start.
Also link it up everywhere.
