From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-28.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5EE5C433ED for ; Fri, 9 Apr 2021 23:36:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6CA89610CA for ; Fri, 9 Apr 2021 23:36:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235191AbhDIXgh (ORCPT ); Fri, 9 Apr 2021 19:36:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35038 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235096AbhDIXgg (ORCPT ); Fri, 9 Apr 2021 19:36:36 -0400 Received: from mail-lj1-x230.google.com (mail-lj1-x230.google.com [IPv6:2a00:1450:4864:20::230]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1799C061763 for ; Fri, 9 Apr 2021 16:36:22 -0700 (PDT) Received: by mail-lj1-x230.google.com with SMTP id y1so8322303ljm.10 for ; Fri, 09 Apr 2021 16:36:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=MQEhdxl+cSU7BC7XRTZDcCsNpOwQL3MJhJomrvmkJCY=; b=naXn5kfXgRlukFVoSCe/aS9mSub16qMDDnXU0x9NB9VvBXEc/nCg53QsttbiYYoOdy NvXp8jYd89b8HUaPN7fRNWO7pgHhHGs0K2z7HvJSpG4ldxCjcMZNSGLrjUXwkFVHREQu EkdeDYJ7eqF5tFBnfniDsngW17bsbFPd/pBe5DFNZhQSWnOUt41ATFBagvjygDaOpiYo 62J7wMp79geIT6GRT+gjXifp+0VcR8gXSKkd4nk/0kY3pkxISXwVA86aOf+t+AdlrKRe U7Y/TWL9S15pzXqvCbz7Fo4iNaFjd0uAUUBxFrQUZ7BwZ3283l1O3CNk3bQetk5ztkO4 RIrw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MQEhdxl+cSU7BC7XRTZDcCsNpOwQL3MJhJomrvmkJCY=; b=FJmjEG8wFMOtNoPUiZVGFuL1E6ob4uC3yOJqps+qquASCPVgYpWJ6MJtyglDelcOfc M9t9RVut3YmRvsVXkzM2gUY5iXgx8KGIXArxvgg5ttBNcuGQZGzOKakD2K9bevRTdGao pQ/ahxeo8fk4J1OTQxcriqVQ//VhauZMLk22t7CU8QkTF4NOG3Ao9E9puHxM6+250SFl Xw7jUHFY8ioSbBnx82Tt2UyEFSIlSmBI3Ccb4gCukVfqRG8B/YSHCwfmB8WXkOzBXoLr 2VTZFViYEyAKtpiZmplr3pkaSmKJ0I3Jokzbz0wCtbuQVUHAPtl5OFqGSNKtUaN7Bthv /0CA== X-Gm-Message-State: AOAM530UXxBO5Ef0kqBDFcEfMWSr1IXxUASIgQ79cKEjuxKW2zRKuKgL FIAN2IUpKsWykQnNWo1sbzbxQgJaQGrc3p7jlrFIMA== X-Google-Smtp-Source: ABdhPJxPZM+yBj5h9pJP265DYko714wL+M/i9xL4wgwVQK69SoBcfbh2i4JxHFXtqH+bSlHJjvuHtaD+RYSUTCWwTuU= X-Received: by 2002:a2e:3603:: with SMTP id d3mr10563594lja.495.1618011380903; Fri, 09 Apr 2021 16:36:20 -0700 (PDT) MIME-Version: 1.0 References: <20210409221155.1113205-1-nathan@kernel.org> In-Reply-To: <20210409221155.1113205-1-nathan@kernel.org> From: Nick Desaulniers Date: Fri, 9 Apr 2021 16:36:09 -0700 Message-ID: Subject: Re: [PATCH] crypto: arm/curve25519 - Move '.fpu' after '.arch' To: Nathan Chancellor Cc: Herbert Xu , "David S. Miller" , Russell King , Ard Biesheuvel , "Jason A. Donenfeld" , "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" , Linux ARM , LKML , clang-built-linux , "# 3.4.x" , Arnd Bergmann , Jessica Clarke Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 9, 2021 at 3:12 PM Nathan Chancellor wrote: > > Debian's clang carries a patch that makes the default FPU mode > 'vfp3-d16' instead of 'neon' for 'armv7-a' to avoid generating NEON > instructions on hardware that does not support them: > > https://salsa.debian.org/pkg-llvm-team/llvm-toolchain/-/raw/5a61ca6f21b4ad8c6ac4970e5ea5a7b5b4486d22/debian/patches/clang-arm-default-vfp3-on-armv7a.patch > https://bugs.debian.org/841474 > https://bugs.debian.org/842142 > https://bugs.debian.org/914268 Another good link would be the one from Jessica describing more precisely what the ARM targets for Debian are: https://wiki.debian.org/ArchitectureSpecificsMemo#armel > > This results in the following build error when clang's integrated > assembler is used because the '.arch' directive overrides the '.fpu' > directive: > > arch/arm/crypto/curve25519-core.S:25:2: error: instruction requires: NEON > vmov.i32 q0, #1 > ^ > arch/arm/crypto/curve25519-core.S:26:2: error: instruction requires: NEON > vshr.u64 q1, q0, #7 > ^ > arch/arm/crypto/curve25519-core.S:27:2: error: instruction requires: NEON > vshr.u64 q0, q0, #8 > ^ > arch/arm/crypto/curve25519-core.S:28:2: error: instruction requires: NEON > vmov.i32 d4, #19 > ^ > > Shuffle the order of the '.arch' and '.fpu' directives so that the code > builds regardless of the default FPU mode. This has been tested against > both clang with and without Debian's patch and GCC. > > Cc: stable@vger.kernel.org > Fixes: d8f1308a025f ("crypto: arm/curve25519 - wire up NEON implementation") > Link: https://github.com/ClangBuiltLinux/continuous-integration2/issues/118 > Reported-by: Arnd Bergmann > Suggested-by: Arnd Bergmann > Suggested-by: Jessica Clarke > Signed-off-by: Nathan Chancellor Great work tracking down that Debian was carrying patches! Thank you! I've run this through the same 3 assemblers. Reviewed-by: Nick Desaulniers Tested-by: Nick Desaulniers > --- > arch/arm/crypto/curve25519-core.S | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/crypto/curve25519-core.S b/arch/arm/crypto/curve25519-core.S > index be18af52e7dc..b697fa5d059a 100644 > --- a/arch/arm/crypto/curve25519-core.S > +++ b/arch/arm/crypto/curve25519-core.S > @@ -10,8 +10,8 @@ > #include > > .text > -.fpu neon > .arch armv7-a > +.fpu neon > .align 4 > > ENTRY(curve25519_neon) > > base-commit: e49d033bddf5b565044e2abe4241353959bc9120 > -- > 2.31.1.189.g2e36527f23 > -- Thanks, ~Nick Desaulniers