Re: [PATCH] lib/crypto: powerpc/md5: Drop powerpc optimized MD5 code

Ard Biesheuvel
2026-05-04T11:43:41Z

On Mon, 4 May 2026, at 06:14, Eric Biggers wrote:
> Earlier the decision was made to keep this code for a while, despite no
> other architectures having optimized MD5 code anymore, because of
> someone using it via AF_ALG via libkcapi-hasher
> (https://lore.kernel.org/r/f0d771d5-ed70-444c-957a-ad4c16f6c115@csgroup.eu/)
>
> However, with AF_ALG itself now being on its way out due to its
> continuous stream of security vulnerabilities
> (https://lore.kernel.org/r/20260430011544.31823-1-ebiggers@kernel.org/),
> it's time to be a bit more forceful with nudging people towards
> userspace crypto code. It's always been the better solution anyway, and
> it's much more efficient if properly optimized code is used.
>
> Thus, drop the PowerPC optimized MD5 code. Note that this code contains
> no privileged instructions and could be run in userspace just fine.
>
> MD5 is still supported, just with the generic code only. I.e., this
> commit only changes performance; it isn't a hard break.
>
> This also has no effect on implementations of md5sum that already just
> use userspace code (as they should), for example the coreutils one.
>
> Signed-off-by: Eric Biggers <ebiggers@kernel.org>

Acked-by: Ard Biesheuvel <ardb@kernel.org>