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 795CF348895; Thu, 26 Mar 2026 23:02:34 +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=1774566154; cv=none; b=niuoJxuGlPu+GeijyCiNYWTVA29D6cwIpgZGJ7CCu3iCo5eVFSoP+ZnNyE/ZiYCFpVcB/xwHnpNV3TW74EctRuU+S+Esqp0zpySWx7LlVRk0ury9HrESVy9fVvmeIgtxXL6UYxadDknzPwprY7Oqlkzg7Js1M/jnt4oq4BDl0Uo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774566154; c=relaxed/simple; bh=+Gaq4pHwzIyQrpjALRkMbCW4mgVtwEeLvMwgKOXH1Hk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BqsyY9p30Uafx6pQokCGDfKyNLbJrP/SI6SpbjP/skcOBVio4mgLmP5jIOoAIZ6SXzm1pe80VCATB5UJLTmPaM2brOWRt8XXlnbYGYmRBZ8ntCxQNaL0Z09I75WVOCSGKsKphRRhElTPmqh1gpQZ2ltYiwd/2yMl68lqUBIbJ1Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hfzPDzzY; 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="hfzPDzzY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCA9EC19424; Thu, 26 Mar 2026 23:02:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774566154; bh=+Gaq4pHwzIyQrpjALRkMbCW4mgVtwEeLvMwgKOXH1Hk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hfzPDzzYl5ryLE4epgtOQRmb0TNQfTZ6YskDruWMcItyi8OR1w28Xpl4QoXlkv62F JqspJIrw9FzCru1gKX8Vz4DhrTcR5KVd0VX6Y4dIqN9HUjCxrQAd6KNyCsZOzksNzx HATHlE4CjZ2Up/vnvqp0kNh3RAuh23cchmhpV/9RYNF4g9pZyAnh/gLnE4+xS+QJ6n WHpJWh58dC8CUSKC8edKB+BS+FgpyqhHkQAvU1sWFmzYyQ5r3ZNRiCW8Z3kBjghxYO Yof9eYBSOCUYOHcbEZMUm/11N3tO2BODKP/uqsEGPHaTAtvegnt97lYYq+5JKH8NiY mohha2OUwFxkg== Date: Thu, 26 Mar 2026 16:02:32 -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: <20260326230232.GA67831@quark> References: <20260326203341.60393-1-ebiggers@kernel.org> 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: 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. - Eric