Devuan bug report logs - #916
/usr/share/initramfs-tools/hooks/kmod broken on armhf for kernels with CONFIG_MODULE_DECOMPRESS

Reply or subscribe to this bug.

Toggle useless messages

Message #5 received at submit@bugs.devuan.org (full text, mbox, reply):

Package: kmod
Version: 34.2-2
Severity: normal
File: /usr/share/initramfs-tools/hooks/kmod
X-Debbugs-Cc: debian-arm@lists.debian.org, dvdkhlng@posteo.de
User: debian-arm@lists.debian.org
Usertags: armhf

Hi,

on armhf, the initramfs-hook of kmod fails intermittently, when the
kernel is compiled with CONFIG_MODULE_DECOMPRESS.  This prevents
update-initramfs from creating any initrd images.

The failure is triggered by these lines:

          copy_exec /usr/lib/*-linux-gnu/liblzma.so.5
          copy_exec /usr/lib/*-linux-gnu/libzstd.so.1

There is no /usr/lib/*-linux-gnu directory on armhf!  The directory is
named /usr/lib/arm-linux-gnueabihf here.  Likely other Debian
architectures are affected by the same bug.

I fixed the issue for me by changing these wildcards to

          copy_exec /usr/lib/*-linux-gnu*/liblzma.so.5
          copy_exec /usr/lib/*-linux-gnu*/libzstd.so.1

Not that I really understand the implications of that change :)

cheers,

David

-- System Information:
Distributor ID:	Devuan
Description:	Devuan GNU/Linux 6 (excalibur)
Release:	6
Codename:	excalibur
Architecture: armv7l

Kernel: Linux 6.12.53-dk2 (SMP w/4 CPU threads)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: sysvinit (via /sbin/init)
LSM: AppArmor: enabled

Versions of packages kmod depends on:
ii  libc6       2.41-12
ii  libkmod2    34.2-2
ii  libssl3t64  3.5.1-1+deb13u1

kmod recommends no packages.

kmod suggests no packages.

-- no debconf information

Message #8 received at 916@bugs.devuan.org (full text, mbox, reply):

Control: tags -1 debian

David,

Thanks for this.

On Wed, Oct 22, 2025 at 12:29:47PM +0000, David Kuehling wrote:
> on armhf, the initramfs-hook of kmod fails intermittently, when the
> kernel is compiled with CONFIG_MODULE_DECOMPRESS.  This prevents
> update-initramfs from creating any initrd images.
> 
> The failure is triggered by these lines:
> 
>           copy_exec /usr/lib/*-linux-gnu/liblzma.so.5
>           copy_exec /usr/lib/*-linux-gnu/libzstd.so.1

The comment above those lines[1] suggest this is for CONFIG_MODULE_DECOMPRESS=n?

> There is no /usr/lib/*-linux-gnu directory on armhf!  The directory is
> named /usr/lib/arm-linux-gnueabihf here.  Likely other Debian
> architectures are affected by the same bug.

As you notice, kmod is not forked in Devuan and we use Debian's packages
directly without recompilation.

The src:kmod d/changelog[2] suggests this code was added to fix Debian
#1099801. Perhaps the fix is wrong or incomplete.

Please report to Debian's BTS for resolution. The reportbug(1) --bts=debian
option might be useful.

Thanks

Mark

[1]  https://salsa.debian.org/md/kmod/-/blob/master/debian/kmod.initramfs-hook?ref_type=heads#L23

[2]  https://tracker.debian.org/media/packages/k/kmod/changelog-34.2-2

Message #15 received at 916@bugs.devuan.org (full text, mbox, reply):

Mark Hindley <mark@hindley.org.uk> writes:

> On Wed, Oct 22, 2025 at 12:29:47PM +0000, David Kuehling wrote:
>> on armhf, the initramfs-hook of kmod fails intermittently, when the
>> kernel is compiled with CONFIG_MODULE_DECOMPRESS.  This prevents
>> update-initramfs from creating any initrd images.
>> 
>> The failure is triggered by these lines:
>> 
>>           copy_exec /usr/lib/*-linux-gnu/liblzma.so.5
>>           copy_exec /usr/lib/*-linux-gnu/libzstd.so.1
>
> The comment above those lines[1] suggest this is for CONFIG_MODULE_DECOMPRESS=n?

You are right, the condition to trigger this bug is more complex than I
thought.  The kernel nedes to be compiled with
CONFIG_MODULE_COMPRESS_ALL (i.e. turning all modules into *.ko.xz
files), then CONFIG_MODULE_DECOMPRESS needs to be disabled, requiring
the userspace to decompress modules for loading.

[..]
> Please report to Debian's BTS for resolution. The reportbug(1) --bts=debian
> option might be useful.

I see, will do so now.

cheers,

David

Send a report that this bug log contains spam.