[Bug 2095518] Re: dracut-install does not install compressed wildcard blobs

[Benjamin Drung]

Uploaded dracut 106-2ubuntu1 with this patch. Sponsored SRUs, but
renamed the oracular version to 103-1ubuntu3.1.

** Changed in: dracut (Ubuntu Plucky)
       Status: In Progress => Fix Committed

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https://bugs.launchpad.net/bugs/2095518

Title:
  dracut-install does not install compressed wildcard blobs

Status in dracut package in Ubuntu:
  Fix Committed
Status in dracut source package in Jammy:
  Triaged
Status in dracut source package in Noble:
  In Progress
Status in dracut source package in Oracular:
  In Progress
Status in dracut source package in Plucky:
  Fix Committed

Bug description:
  [SRU Justificaiton]

  [ Impact ]

  Linux kernel modules may declare firmware blobs to be installed along
  with the module itself to ensure driver functions, and the paths may
  contains wildcards to be expanded by other tools.

  ```
  $ find /lib/modules/$(uname -r) -name \*.ko.zst -exec bash -c "m=\$(basename "{}"); m=\${m%%.*}; modinfo \$m|grep '^firmware:.*\*'" \;
  firmware: brcm/brcmbt4388*.ptb
  firmware: brcm/brcmbt4388*.bin
  firmware: brcm/brcmbt4387*.ptb
  firmware: brcm/brcmbt4387*.bin
  firmware: brcm/brcmbt4378*.ptb
  firmware: brcm/brcmbt4378*.bin
  firmware: brcm/brcmbt4377*.ptb
  firmware: brcm/brcmbt4377*.bin
  firmware: intel/ish/ish_*.bin
  firmware: ath11k/WCN6855/hw2.1/*
  firmware: ath11k/WCN6855/hw2.0/*
  firmware: ath11k/QCN9074/hw1.0/*
  firmware: ath11k/QCA6390/hw2.0/*
  firmware: brcm/brcmfmac*-sdio.*.bin
  firmware: brcm/brcmfmac*-sdio.*.txt
  firmware: brcm/brcmfmac*-pcie.*.txcap_blob
  firmware: brcm/brcmfmac*-pcie.*.clm_blob
  firmware: brcm/brcmfmac*-pcie.*.bin
  firmware: brcm/brcmfmac*-pcie.*.txt
  firmware: brcm/brcmfmac*-pcie.txt
  ```

  dracut is the tool that helps building initramfs at this moment, and
  it's implementation for resolving compressed firmware blobs (and
  therefore a different filename suffix) doesn't really handle it
  (wildcard in the middle) correctly. This causes wildcard firmwares,
  even needed by the system, may not be packed into initramfs as
  expected.

  Usually this is not a big deal, and we have been switching to xz/zst
  for a while. However, in Intel ISH driver, it declares:

  ```
  firmware:       intel/ish/ish_*.bin
  firmware:       intel/ish/ish_lnlm.bin
  ```

  It tries to resolve the best match of a vendor/model specific
  configuration by DMI info, and since the ones matched with that
  wildcard filename will never be installed into initramfs, leaving only
  the generic blob available and always available at driver loading, it
  will use the generic firmware unconditionally and break sensor
  functions for a few platforms.

  The fix tries to rewrite the resolution in dracut a bit, so that it
  will match and copy compressed blobs as well.

  [ Test Plan ]

  1. touch `/lib/firmware/intel/ish/ish_foo.bin.zst`
  2. `update-initramefs -v -u -k $(uname -r)`, and check if above file was added.

  [ Where problems could occur ]

   * This fix will then add brcm, ish firmware blobs into initramfs if
  necessary for the running platform as they should have been. Would
  slightly increase initramfs size if affected.

  [ Other Info ]

  * First found for dracut >= 060, used by Ubuntu Noble, and extent to
  Jammy/Oracular/Plucky as well.

  * Upstream bug and pull request in review: https://github.com/dracut-
  ng/dracut-ng/issues/1150

  ========== original bug report ==========

  [Describe the bug]

  Take kernel module intel-ish-ipc for example, it has two firmware
  declarations:

  ```
  $ modinfo intel-ish-ipc | grep ^firmware
  firmware: intel/ish/ish_*.bin
  firmware: intel/ish/ish_lnlm.bin
  ```

  And with additional custom ISH firmware installed from [bug
  2094768](https://bugs.launchpad.net/bugs/2094768), update-initramefs
  gives:

  ```
  $ update-initramefs -v -u -k $(uname -r)
  ...
  dracut-install: Missing firmware intel/ish/ish_*.bin for kernel module intel_ish_ipc
  dracut-install: mkdir '/var/tmp/mkinitramfs_9uk7FI/lib/firmware/intel/ish'
  dracut-install: cp '/lib/firmware/intel/ish/ish_lnlm_39ceeaf8_58.7724.2.bin.zst' '/var/tmp/mkinitramfs_9uk7FI/lib/firmware/intel/ish/ish_lnlm_39ceeaf8_58.7724.2.bin.zst'
  dracut-install: ln -s 'ish_lnlm_39ceeaf8_58.7724.2.bin.zst' '/var/tmp/mkinitramfs_9uk7FI/lib/firmware/intel/ish/ish_lnlm.bin.zst'
  ...
  ```

  In source code for `/usr/lib/dracut/dracut-install`, that is, source
  package dracut, file `src/install/dracut-install.c`, function
  `install_firmware`, it tries to invoke `glob()` with full path
  expanded from "intel/ish/ish_*.bin", but while all the binaries were
  compressed, this matches no file and none of the custom ISH firmware
  blobs will be installed.

  [Distribution used]

  Ubuntu

  [Dracut version]

  This was first found in Ubuntu/Noble, which has 060, but from the git
  history and the differences, this should be reproducible with all
  versions of dracut.

  [Init system]

  Systemd.

  [To Reproduce]

  1. touch `/lib/firmware/intel/ish/ish_foo.bin.zst`
  2. `update-initramefs -v -u -k $(uname -r)`, and check if above file was added.

  [Expected behavior]

  Any file under `/lib/firmware/intel/ish` matches
  `intel/ish/ish_*.bin`, compressed (.zst, .xz) or uncompressed (.bin),
  should be added into the newly created initramefs.

  [Additional context]

  Upstream bug: https://github.com/dracut-ng/dracut-ng/issues/1150

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