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 2B588139B; Mon, 21 Jul 2025 04:18:23 +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=1753071504; cv=none; b=ZqnGDXRsdD/djQI1Ar3eWK42Y+mqirG9kPS2NB6sctFti2PFoC33fB3OlrnKhTN5pN3yKsqVDFFv/MV6oiyrw94+3Dc4SeIeAl4EoPhZGMQ67jLJwyg0Uzb0nbfOaSY9sSJbSCsWrpb1ca7LOsI8/nVxopS8+xF36B3VgLG+9rE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753071504; c=relaxed/simple; bh=seQWfNuMVmyihCKpCTMeU9CJJYqh/Fo379bjZ/VmuxQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TC6XAmeLklyh2a6IQdapzutIhUeMwVFdEt7TtWvOKbBZCNZlDDgbxjNW8frFwP+Zj8tTa3fp7exAGe/wSbuqQL1t4Z42jNUOCk/TwRETwn94/XujtnKyDYaSq+T/rpKjGYL0jefJX5tZCEQKvXrJYHpJHjY4t92L30PezlJPhX0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YTtMxOTP; 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="YTtMxOTP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 81797C4CEF1; Mon, 21 Jul 2025 04:18:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753071503; bh=seQWfNuMVmyihCKpCTMeU9CJJYqh/Fo379bjZ/VmuxQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YTtMxOTPjd7MKWNvvkeeVPk9smErtwp04Rb17iw342NCepv5QlT7ben5f0G/Qhbq3 3NdeICgNq2VYTmcpqbNT248HVbm4AhezD5xfOuV89RTqlqh77miE0CTsDBh7oq243f Vu8682zZlzi4KhrlAjb44waI9kRdaiNjHk5WMcPEXcHmSFZkbN1ZEuzFTVcFL3/oJw nWlmEchS5ZLohmMTQnPcYiwNBKarV3qioKaOpMt7gG+DvJs4pAz4Arxk8inWWIXZPJ nGrOIWB1l5JSYhHqVNg+HiQUH1EecI9+ml8roM288Se7xh60NtlfLONex0/f8ocLtM SWaNymQ6dtgmw== Date: Sun, 20 Jul 2025 21:17:35 -0700 From: Eric Biggers To: Ard Biesheuvel Cc: linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, "Jason A . Donenfeld" Subject: Re: [PATCH] lib/crypto: arm64/sha512-ce: Drop compatibility macros for older binutils Message-ID: <20250721041735.GA3372@sol> References: <20250718220706.475240-1-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@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 Mon, Jul 21, 2025 at 01:31:47PM +1000, Ard Biesheuvel wrote: > On Sat, 19 Jul 2025 at 08:07, Eric Biggers wrote: > > > > Now that the oldest supported binutils version is 2.30, the macros that > > emit the SHA-512 instructions as '.inst' words are no longer needed. So > > drop them. No change in the generated machine code. > > > > Changed from the original patch by Ard Biesheuvel: > > (https://lore.kernel.org/r/20250515142702.2592942-2-ardb+git@google.com): > > - Reduced scope to just SHA-512 > > - Added comment that explains why "sha3" is used instead of "sha2" > > > > Signed-off-by: Eric Biggers > > Acked-by: Ard Biesheuvel > > Nit below > > > --- > > > > This patch is targeting libcrypto-next > > > > lib/crypto/arm64/sha512-ce-core.S | 27 +++++++-------------------- > > 1 file changed, 7 insertions(+), 20 deletions(-) > > > > diff --git a/lib/crypto/arm64/sha512-ce-core.S b/lib/crypto/arm64/sha512-ce-core.S > > index 7d870a435ea38..eaa485244af52 100644 > > --- a/lib/crypto/arm64/sha512-ce-core.S > > +++ b/lib/crypto/arm64/sha512-ce-core.S > > @@ -10,30 +10,17 @@ > > */ > > > > #include > > #include > > > > - .irp b,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19 > > - .set .Lq\b, \b > > - .set .Lv\b\().2d, \b > > - .endr > > - > > - .macro sha512h, rd, rn, rm > > - .inst 0xce608000 | .L\rd | (.L\rn << 5) | (.L\rm << 16) > > - .endm > > - > > - .macro sha512h2, rd, rn, rm > > - .inst 0xce608400 | .L\rd | (.L\rn << 5) | (.L\rm << 16) > > - .endm > > - > > - .macro sha512su0, rd, rn > > - .inst 0xcec08000 | .L\rd | (.L\rn << 5) > > - .endm > > - > > - .macro sha512su1, rd, rn, rm > > - .inst 0xce608800 | .L\rd | (.L\rn << 5) | (.L\rm << 16) > > - .endm > > + /* > > + * While SHA-512 is part of the SHA-2 family of algorithms, the > > + * corresponding arm64 instructions are actually part of the "sha3" CPU > > + * feature. (Except in binutils 2.30 through 2.42, which used "sha2". > > Nit: the ARM ARM describes these features as FEAT_SHA256, FEAT_SHA512 > and FEAT_SHA3, and the latter two happen to have appeared in the same > architecture revision. So this is likely just the GCC/binutils devs > getting confused, and assuming a) that SHA-3 implies SHA-2 (which is > silly if you know the difference) and b) SHA512 has anything to do > with SHA-3. How does the following look? /* * We have to specify the "sha3" feature here, since the GNU and clang * assemblers both consider the SHA-512 instructions to be part of the * "sha3" feature. (Except binutils 2.30 through 2.42, which used * "sha2". But "sha3" implies "sha2", so "sha3" still works in those * versions.) "sha3" doesn't make a lot of sense, since SHA-512 is part * of the SHA-2 family of algorithms, and also the Arm Architecture * Reference Manual defines FEAT_SHA512 and FEAT_SHA3 separately. * Regardless, we must use "sha3" to be compatible with the assemblers. */ By the way, the ARM ARM does actually have the following: If FEAT_SHA256 is implemented, then FEAT_SHA1 is implemented. If FEAT_SHA512 is implemented, then FEAT_SHA256 and FEAT_SHA1 are implemented. If FEAT_SHA3 is implemented, then FEAT_SHA256 and FEAT_SHA1 are implemented. So some of the SHAs do imply other ones. But notably absent is FEAT_SHA3 implying FEAT_SHA512... - Eric