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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 064E2C433DB for ; Fri, 15 Jan 2021 23:25:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9A0D239ED for ; Fri, 15 Jan 2021 23:25:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728272AbhAOXZM (ORCPT ); Fri, 15 Jan 2021 18:25:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38706 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726239AbhAOXZJ (ORCPT ); Fri, 15 Jan 2021 18:25:09 -0500 Received: from mail-lj1-x22f.google.com (mail-lj1-x22f.google.com [IPv6:2a00:1450:4864:20::22f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 332A5C061757 for ; Fri, 15 Jan 2021 15:24:27 -0800 (PST) Received: by mail-lj1-x22f.google.com with SMTP id f17so12097983ljg.12 for ; Fri, 15 Jan 2021 15:24:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=lspkB+h5s6b8Zyih98xTfXCRcGn+GFR4ecpzXtZclcQ=; b=VCNEYkEerxNDCrTb2mbn7JMafLojLFMdQLNUQfC/wOLAL4m2Ta+MvY725eGmDVqfnn H7hwRghFneD6WqMDm/Q/QhCiCow/CkY/+gFvcUeWCS0WRy4nZ6muR/2qyOkHE9wI78Kz gdFOqzLN74IPJor0B8Y5gNPtcoiNIILZOGCMc= 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=lspkB+h5s6b8Zyih98xTfXCRcGn+GFR4ecpzXtZclcQ=; b=EwXbC+0w9Gkibmuspu1vrm7qGSw1sxWmgeT1RR4UUow2RvWNg5G4LBCZjCV4EYCsCu mXwN8VSNSgrLrU26YmSUnNHH/QXv6KuDq9sTW4SQEY+Xk2mab1k35HJF+HOPtr+YaH4V hBRI48ru5B4rcFkLIJwx/5HyYOeQ8gMCgt6hBNGLgjQVatGD2i9lY0czG/RmOesbPQQT upfZKAehB2mVevgtPST6deR0iIRKPiB9/j9Z7N8rlTVXmYO3LLZz6IKG5f5Gr85IYQza JoOeEjCr3N9/iz5iuRcfmFoOPoRq/AV5exnbeFTs7QlyeacqHQsKGs7RKHBbSF7Fui13 qHeQ== X-Gm-Message-State: AOAM532FiLEgumhrhoNVStcL+8Z0J7DxH6pV5340XGDC1HX16nY9Iiia H79CzGQc2HdBhuUuKb/TRaJXDs3wJrrE6Q== X-Google-Smtp-Source: ABdhPJzrUx8CvxnM07/KVWDGYP/5kdumZaDidS5i5HlkKfTdQ9ka50jA0dTnqWczEshkpqqThMlE3g== X-Received: by 2002:a05:651c:cb:: with SMTP id 11mr6120561ljr.509.1610753065309; Fri, 15 Jan 2021 15:24:25 -0800 (PST) Received: from mail-lj1-f170.google.com (mail-lj1-f170.google.com. [209.85.208.170]) by smtp.gmail.com with ESMTPSA id 206sm1078048lfd.180.2021.01.15.15.24.23 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 15 Jan 2021 15:24:23 -0800 (PST) Received: by mail-lj1-f170.google.com with SMTP id f17so12097878ljg.12 for ; Fri, 15 Jan 2021 15:24:23 -0800 (PST) X-Received: by 2002:a2e:3211:: with SMTP id y17mr5928600ljy.61.1610753063004; Fri, 15 Jan 2021 15:24:23 -0800 (PST) MIME-Version: 1.0 References: <20210112224832.10980-1-will@kernel.org> <161055398865.21762.12236232732054213928.b4-ty@arm.com> <20210113214436.GL1551@shell.armlinux.org.uk> In-Reply-To: From: Linus Torvalds Date: Fri, 15 Jan 2021 15:24:07 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] compiler.h: Raise minimum version of GCC to 5.1 for arm64 To: Joe Perches Cc: Ard Biesheuvel , Russell King - ARM Linux admin , Florian Weimer , Arnd Bergmann , "Cc: Android Kernel" , "Theodore Ts'o" , Peter Zijlstra , Catalin Marinas , Masahiro Yamada , Nick Desaulniers , Linux Kernel Mailing List , Will Deacon , linux-arm-kernel Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 14, 2021 at 4:30 PM Joe Perches wrote: > > KASAN v5 instead of all the old versions > gcc 7.1 supports fallthrough. Considering that most people won't even enable KASAN, I think that's not a huge reason to then force people to potentially upgrade their compilers. That said, I do think that it might be good to just try to standardize on the KASAN v5 code - but that could easily be done by simply making KASAN depend as a feature on having a newer compiler version. So the KASAN option itself could just have something like depends on !CC_IS_GCC || GCC_VERSION >= 70000 in it, which would allow us to just say "only v5 need apply". As to "fallthrough", I think it's more than enough that lots of people build with compilers that support it, and then any warnings they see will be fixed. No need to force upgrades - it doesn't buy kernel developers anything. Linus