Re: [PATCH] x86/entry/32: Harden return-to-user

[s1nkhole]

From: Andrey Zakharov <dedemorow@xxxxxxxxx>

On 10/27/26 15:01, Dave Hansen wrote:
> I'm curious who cares.
>
> Is anyone who is actually still running a 32-bit kernel concerned about
> this kind of hardening?
>
> If no one cares, then I'd rather pass on the complexity, even four
> instructions of it.

I don't know of anyone. The only motivation was KSPP issue #41, which
asks for parity with the x86-64 check added by 1e4d3001f59f, and that
issue is marked as low priority because 32-bit is legacy. I have no
report from a 32-bit user asking for it.

Please drop the patch. Thanks for looking at it.

If you have a moment: this is my first work on arch/x86, and I would like
to contribute something that is actually useful. Is there a small task
in x86/entry or in kernel hardening that you would suggest as a better
starting point, or a place where help with testing or review would be
welcome? I can build and run kernels under QEMU.

Thanks,
Andrey Zakharov