Re: [RFC PATCH 0/8] s390: Remove compat support

[Arnd Bergmann]

On Mon, Nov 10, 2025, at 19:54, Heiko Carstens wrote:
> Remove s390 compat support to allow for code simplification and especially
> reduced test effort. To the best of our knowledge there aren't any 31 bit
> binaries out in the world anymore that would matter for newer kernels or
> newer distributions.
>
> Distributions do not provide compat packages since quite some time or even
> have CONFIG_COMPAT disabled.
>
> Instead of adding deprecation warnings to config option, or adding kernel
> messages, just remove the code. Deprecation warnings haven't proven to be
> useful. If it turns out there is still a reason to keep the compat support
> this series can be reverted at any time in the future.
>
> Arnd, we talked about this two weeks ago. I would appreciate if you could
> have a look at this series, especially the last patch of this series.
>
> Patches 1-3 are just some random cleanups / preparations.
> Patches 4-6 remove compat support.
> Patches 7-8 switch s390 to generic system call table generation

Loooks good to me overall,

Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>

I agree it's rather unlikely that anyone is still using 31-bit
binaries, it was only really from 2000 to 2002 that commercial
distros were missing s390x support. Debian moved to 64-bit-only
much later than the others, but had both fewer user and fewer
third-party applications that might require old binaries.

      Arnd