[Bug 1988078] [NEW] Please backport systemd-hwdb patches to support src:systemd-hwe tests

[Nick Rosbrook]

Public bug reported:

[Impact]

We plan to SRU src:systemd-hwe to Jammy[1] to provide an easier way to
SRU HWE hwdb rules to Ubuntu. The src:systemd-hwe package contains a
test script[2] to ensure that no redundant hwdb rules are added to the
package, i.e. rules that are already present in src:systemd. This test
requires patches to implement --root flag support for the `systemd-hwdb
query` command[3]. These patches are already present in kinetic.

Without these patches in Jammy, src:systemd-hwe would have to disable
these tests, which are important to maintaining HWE hwdb rules in
Ubuntu.

[1] https://bugs.launchpad.net/ubuntu/+source/systemd-hwe/+bug/1983996
[2] https://git.launchpad.net/~canonical-foundations/+git/systemd-hwe/tree/tests/hwdb-redundancy?h=main
[3] https://github.com/systemd/systemd/pull/23518

[Test plan]

* Create a new directory for testing hwdb rule queries:

$ mkdir -p fakeroot/etc/udev/hdwb.d

* Add a new .hwdb file to override an existing rule. For example, I
chose to override the last entry from /lib/udev/hdwb.d/60-keyboard.hwdb:

$ tail -2 /lib/udev/hwdb.d/60-keyboard.hwdb > fakeroot/etc/udev/hwdb.d/60-keyboard.hwdb
$ sed -i 's/chromebook/reserved/g' fakeroot/etc/udev/hwdb.d/60-keyboard.hwdb 
$ cat fakeroot/etc/udev/hwdb.d/60-keyboard.hwdb 
evdev:atkbd:dmi:bvn*:bvr*:bd*:svnAcer*:pnPeppy:*
 XKB_FIXED_MODEL=reserved

* Create the hwdb.bin within fakeroot:

$ systemd-hwdb update --root fakeroot
$ ls fakeroot/etc/udev/hwdb.bin 
fakeroot/etc/udev/hwdb.bin

* Finally, attempt to query this new hwdb.bin using systemd-hwdb query.
On an unpatched system, we will see results from the system's hwdb.bin:

$ systemd-hwdb query --root fakeroot evdev:atkbd:dmi:bvn*:bvr*:bd*:svnAcer*:pnPeppy:* | grep XKB_FIXED_MODEL
XKB_FIXED_MODEL=chromebook

...and on a patched system we should see the overridden rule:

$ systemd-hwdb query --root fakeroot evdev:atkbd:dmi:bvn*:bvr*:bd*:svnAcer*:pnPeppy:* | grep XKB_FIXED_MODEL
XKB_FIXED_MODEL=reserved 

[Where problems could occur]
The patches add support for the --root flag when calling systemd-hwdb query, thus changing the behavior of this command (previously, query would always load the system's hwdb.bin). It is unlikely that existing scripts try to use the --root flag with `systemd-hwdb query`, but if they did, this is where we would see problems.

** Affects: systemd (Ubuntu)
     Importance: Undecided
         Status: New

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1988078

Title:
  Please backport systemd-hwdb patches to support src:systemd-hwe tests

Status in systemd package in Ubuntu:
  New

Bug description:
  [Impact]

  We plan to SRU src:systemd-hwe to Jammy[1] to provide an easier way to
  SRU HWE hwdb rules to Ubuntu. The src:systemd-hwe package contains a
  test script[2] to ensure that no redundant hwdb rules are added to the
  package, i.e. rules that are already present in src:systemd. This test
  requires patches to implement --root flag support for the `systemd-
  hwdb query` command[3]. These patches are already present in kinetic.

  Without these patches in Jammy, src:systemd-hwe would have to disable
  these tests, which are important to maintaining HWE hwdb rules in
  Ubuntu.

  [1] https://bugs.launchpad.net/ubuntu/+source/systemd-hwe/+bug/1983996
  [2] https://git.launchpad.net/~canonical-foundations/+git/systemd-hwe/tree/tests/hwdb-redundancy?h=main
  [3] https://github.com/systemd/systemd/pull/23518

  [Test plan]

  * Create a new directory for testing hwdb rule queries:

  $ mkdir -p fakeroot/etc/udev/hdwb.d

  * Add a new .hwdb file to override an existing rule. For example, I
  chose to override the last entry from
  /lib/udev/hdwb.d/60-keyboard.hwdb:

  $ tail -2 /lib/udev/hwdb.d/60-keyboard.hwdb > fakeroot/etc/udev/hwdb.d/60-keyboard.hwdb
  $ sed -i 's/chromebook/reserved/g' fakeroot/etc/udev/hwdb.d/60-keyboard.hwdb 
  $ cat fakeroot/etc/udev/hwdb.d/60-keyboard.hwdb 
  evdev:atkbd:dmi:bvn*:bvr*:bd*:svnAcer*:pnPeppy:*
   XKB_FIXED_MODEL=reserved

  * Create the hwdb.bin within fakeroot:

  $ systemd-hwdb update --root fakeroot
  $ ls fakeroot/etc/udev/hwdb.bin 
  fakeroot/etc/udev/hwdb.bin

  * Finally, attempt to query this new hwdb.bin using systemd-hwdb
  query. On an unpatched system, we will see results from the system's
  hwdb.bin:

  $ systemd-hwdb query --root fakeroot evdev:atkbd:dmi:bvn*:bvr*:bd*:svnAcer*:pnPeppy:* | grep XKB_FIXED_MODEL
  XKB_FIXED_MODEL=chromebook

  ...and on a patched system we should see the overridden rule:

  $ systemd-hwdb query --root fakeroot evdev:atkbd:dmi:bvn*:bvr*:bd*:svnAcer*:pnPeppy:* | grep XKB_FIXED_MODEL
  XKB_FIXED_MODEL=reserved 

  [Where problems could occur]
  The patches add support for the --root flag when calling systemd-hwdb query, thus changing the behavior of this command (previously, query would always load the system's hwdb.bin). It is unlikely that existing scripts try to use the --root flag with `systemd-hwdb query`, but if they did, this is where we would see problems.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1988078/+subscriptions