From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E8629395249; Fri, 27 Mar 2026 20:14:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774642499; cv=none; b=E8B+HLCn/P1kSV05/p6STgp15TBdnteDqcqBcHfmQkpTY/G/WvkrB2TxMQ7nrNq9oqUgmK/VdDxHw+I6zOJlOdLqywmvrQAgbYSBEyD2Feh2VN0ZKl3XdkChglttGOB7tckA8/w6+3q9ryKC5tW6WFAD1W3RE1xhCqxS3HNJUAo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774642499; c=relaxed/simple; bh=PnC1orF1BcpDcHQCyAGp11l4TWiGkuasZIyUwy6Alow=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pY0f6EFT7Jbqcw24TQwQFTnEKOejrHa8Bn8UJ2OlX/w+n2TMEJ8pMThR+WGbvNv1Q+bftzetg1e8S3pRGp11g1fIJMAKLFHXxo0p6t/9t63NSnxICdF2fjeoAoSegLmsblt/WQjL3468JyIyic5q1LC/Eu0VKzbDWj9+un8vAPk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Gnux8i6h; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Gnux8i6h" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3571DC2BC86; Fri, 27 Mar 2026 20:14:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774642498; bh=PnC1orF1BcpDcHQCyAGp11l4TWiGkuasZIyUwy6Alow=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Gnux8i6hhx5uxYa27SzezYKXcWErdV4JrawqD5wK343/mH88msF5WVcN/rvKJcYpd 2TNUcnQFwYudcIj0NTZ0LUAUOtjKWNWI08e9durUMJEx+G8+J29Gkx6XI2xCS0ZMIJ abqIzfzb2zpzC3GI5vGexZLBOC5QOpf/cPgUa/LtgRGem3f4/9abLA0b/pl9Ask4FX w9O38eziXvgtoSrMnT1nTA7RrmrBk1gDEx9GnzCqE0sF0a0q4G/Jiz5mbfiWvSnuBQ eq+RmHWMo7D4jGCA37qu0l8VLMgIxqOWYPkEuMEoQg++CB/hGpP9ZqM77nMz9nMJwR rWuXB5kTg2/qw== Date: Fri, 27 Mar 2026 13:14:56 -0700 From: Eric Biggers To: John Paul Adrian Glaubitz Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Ard Biesheuvel , "Jason A . Donenfeld" , Herbert Xu , sparclinux@vger.kernel.org Subject: Re: [PATCH] lib/crypto: sparc: Drop optimized MD5 code Message-ID: <20260327201456.GB25969@quark> References: <20260326203341.60393-1-ebiggers@kernel.org> <20260326230232.GA67831@quark> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260326230232.GA67831@quark> On Thu, Mar 26, 2026 at 04:02:32PM -0700, Eric Biggers wrote: > On Thu, Mar 26, 2026 at 10:51:01PM +0100, John Paul Adrian Glaubitz wrote: > > On Thu, 2026-03-26 at 13:33 -0700, Eric Biggers wrote: > > > MD5 is obsolete. Continuing to maintain architecture-optimized > > > implementations of MD5 is unnecessary and risky. It diverts resources > > > from the modern algorithms that are actually important. > > > > Why is it risky? That makes no sense. > > Because there can be issues in architecture-optimized algorithm > implementations that don't exist in the generic implementations. That's > a very common class of issue that has repeated over time. > > > I also don't see how it diverts resources as no one is forced to work > > on the code. > > > > SPARC is an architecture used by hobbyists and in space these days (in > > the form of Leon). I don't think any other kernel developer will have > > to take a look at it. > > Huh? We've been refactoring how the various crypto and CRC algorithms > are integrated, for all architectures. > > So people outside the SPARC community, especially myself, been having to > spend quite a bit of time updating the SPARC code so that it can still > be used. > > And this isn't new. I've had to patch arch/sparc/crypto/ many times > over the years as things change in the crypto subsystem. Many other > people, again outside the SPARC community, have as well. > > The fact that you're denying that we've had to do this is really > frustrating. There is a significant maintenance cost to keeping this > code working, which is being paid by people outside the SPARC community. > > It seems best to at least focus that effort on modern algorithms like > AES and SHA-256, and not obsolete ones like MD5 and DES. Note that > dropping those eliminates the need to add them to QEMU, as well. > > I think that makes things easier for everyone. Let me know if you're aware of a real user that needs the obsolete MD5 algorithm to be accelerated for SPARC in the kernel. Otherwise, I suggest we proceed with this patch, as this objection seems to based only on principles and misunderstandings. I think our interests are aligned, actually: we both want Linux to work reliably on SPARC. - Eric