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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL autolearn=ham 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 07FCFC433DB for ; Thu, 25 Feb 2021 21:11:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B972E64EBA for ; Thu, 25 Feb 2021 21:11:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229566AbhBYVLx (ORCPT ); Thu, 25 Feb 2021 16:11:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53318 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231160AbhBYVCE (ORCPT ); Thu, 25 Feb 2021 16:02:04 -0500 Received: from mail-lj1-x229.google.com (mail-lj1-x229.google.com [IPv6:2a00:1450:4864:20::229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94431C06174A for ; Thu, 25 Feb 2021 13:01:17 -0800 (PST) Received: by mail-lj1-x229.google.com with SMTP id 2so3567134ljr.5 for ; Thu, 25 Feb 2021 13:01:17 -0800 (PST) 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=7bPn1CTU2aFElE/GlnQTS2oN7n5wO4Fs2imlJntYkTw=; b=EruuQTwqE3lqMBIPcITdvKno7SehJMpApPb/pZBloV8AeuWgS9dxXFa6S4CP4mZ8HL A+tb06UdX2iUYozJx3n+oi47NwcNF7GDkUne5DiViTr597HVoysxV3C7wouzWE2dOfcS cFzQSoYBl9ccSrQNoOMVsxd6sFLL30yoKSSan1RODGpFPCSnKGeM9vzneAVkuZlyLzRh cYK8t4kzn5/jw7C34l0RDZswrCnO0E+IFiGa3MppykDoLR3yPJNi6+R8sCfI6ZPLZHLH k/ey0/m9jFHolcEH1Zu8vZq+pEpIHLwFGCnk+82CvgzG8cfOeD2L1N521s91kcAU5Kry v6aw== 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=7bPn1CTU2aFElE/GlnQTS2oN7n5wO4Fs2imlJntYkTw=; b=TS3XS8RuiXwYS5phYocEvLFUjPxduRPuzDVffI32LOJijqW9KWLJSIXn3R0QebpP2B xtS1gL9ocO3WvIPI2zQvIkpSGSt40dNFGRETMdQ1ICxOzuAvwso00K1NuCaex8bbRlWj sJIKKPeeD0qo6TD6VBkE5MeZUqZwGcnoa+B+eMIabG/fXiB4lsr2BETl5cx7DIalwk34 UUg26awsWZw3CKK7LAy1FshsYIz1ColT3Y9dX2ei4/qqdpJKEeWAVxbXTcQZjTld2TfA l69PR54c3i7bgRO1Q5PtlwU2txl3mJcUQmAJgz5oSOWPsXi4HuEIB5P7IDnttN9w2H6V ha0g== X-Gm-Message-State: AOAM530gWMwFC2cGJkSpgbXOvLJuYt30OOdfgn5I7z4IC2yMG3LvjMhJ 0rGZUrq4JoQsI//Ino8TcSqoqF0P+jzlfVcGv8/i6g== X-Google-Smtp-Source: ABdhPJy7eeRazFH/rVJHDxRwOUgQEHaxudPSRiK9Via/RVV1Cb4qT+kTMEiqV0YlhjqK0Sfrlv9ZGlnDsn5I87Dwxis= X-Received: by 2002:a05:651c:2112:: with SMTP id a18mr2618568ljq.341.1614286875687; Thu, 25 Feb 2021 13:01:15 -0800 (PST) MIME-Version: 1.0 References: <20210225164513.3667778-1-arnd@kernel.org> <202102251203.03762F77@keescook> <20210225120637.8e2a234f192952829fc5f471@linux-foundation.org> In-Reply-To: <20210225120637.8e2a234f192952829fc5f471@linux-foundation.org> From: Nick Desaulniers Date: Thu, 25 Feb 2021 13:01:04 -0800 Message-ID: Subject: Re: [PATCH] linux/compiler-clang.h: define HAVE_BUILTIN_BSWAP* To: Andrew Morton Cc: Kees Cook , Arnd Bergmann , Masahiro Yamada , Nathan Chancellor , Arnd Bergmann , Miguel Ojeda , Marco Elver , Sami Tolvanen , Arvind Sankar , Randy Dunlap , clang-built-linux , LKML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 25, 2021 at 12:06 PM Andrew Morton wrote: > > On Thu, 25 Feb 2021 12:03:48 -0800 Kees Cook wrote: > > > On Thu, Feb 25, 2021 at 05:45:09PM +0100, Arnd Bergmann wrote: > > > From: Arnd Bergmann > > > > > > Separating compiler-clang.h from compiler-gcc.h inadventently dropped the > > > definitions of the three HAVE_BUILTIN_BSWAP macros, which requires falling > > > back to the open-coded version and hoping that the compiler detects it. > > > > > > Since all versions of clang support the __builtin_bswap interfaces, > > > add back the flags and have the headers pick these up automatically. > > > > > > This results in a 4% improvement of compilation speed for arm defconfig. > > > > > > Fixes: 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive") > > > Signed-off-by: Arnd Bergmann > > > > Cc: stable@vger.kernel.org > > I figured 4% better compile time isn't significant enough to justify a > backport. Thoughts? If I made a mistake in 815f0ddb346c, then it would be important to correct it since 815f0ddb346c has existed for a few stable branches (first landed in v4.19-rc1). Acked-by: Nick Desaulniers > > > Reviewed-by: Kees Cook > -- Thanks, ~Nick Desaulniers