Re: [PATCH v4 08/13] crypto: s390/sha256 - implement library instead of shash

[Eric Biggers <ebiggers@kernel.org>]

On Thu, May 29, 2025 at 11:05:26AM -0600, Alex Williamson wrote:
> On Mon, 28 Apr 2025 10:00:33 -0700
> Eric Biggers <ebiggers@kernel.org> wrote:
> 
> > From: Eric Biggers <ebiggers@google.com>
> > 
> > Instead of providing crypto_shash algorithms for the arch-optimized
> > SHA-256 code, instead implement the SHA-256 library.  This is much
> > simpler, it makes the SHA-256 library functions be arch-optimized, and
> > it fixes the longstanding issue where the arch-optimized SHA-256 was
> > disabled by default.  SHA-256 still remains available through
> > crypto_shash, but individual architectures no longer need to handle it.
> 
> I can get to the following error after this patch, now merged as commit
> b9eac03edcf8 ("crypto: s390/sha256 - implement library instead of shash"):
> 
> error: the following would cause module name conflict:
>   crypto/sha256.ko
>   arch/s390/lib/crypto/sha256.ko

Thanks for reporting this.  For now the s390 one should be renamed to
sha256-s390, similar to how the other architectures' sha256 modules are named.
I'll send a patch.

Long-term, I'd like to find a clean way to consolidate the library code for each
algorithm into a single module.  So instead of e.g. libsha256.ko,
libsha256-generic.ko, and sha256-s390.ko (all of which get loaded when the
SHA-256 library is needed), we'd just have libsha256.ko.  (Or just sha256.ko,
with the old-school crypto API one renamed to sha256-cryptoapi.ko.)  A lot of
these weird build problems we've been having are caused by the unnecessary
separation into multiple modules.

- Eric