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,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 7EF9AC2D0E4 for ; Tue, 24 Nov 2020 21:33:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A833208FE for ; Tue, 24 Nov 2020 21:33:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="lzAwh4po" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732650AbgKXVcz (ORCPT ); Tue, 24 Nov 2020 16:32:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732601AbgKXVcu (ORCPT ); Tue, 24 Nov 2020 16:32:50 -0500 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C06D8C094241 for ; Tue, 24 Nov 2020 13:32:47 -0800 (PST) Received: by mail-pf1-x444.google.com with SMTP id b6so293699pfp.7 for ; Tue, 24 Nov 2020 13:32:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=nUebvx46WK355IC8BSYKhA86maU/C5TyOra9y/oS07E=; b=lzAwh4po+9zegkg/2K9x7CHiUUthvj2PFJyxHwt1QdcZQIdrGCSiE3JgzWuDiv+VMN KwBJ/6n/jsAIvSMb6eOJqvl2BVv6D2OMXP8giSKXaaH9JwLNdR2oULKAXe3g8bDVfAub 65Ll+320/JpDsvMBOWCFVSOrRLSDK1WOgK6ns= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=nUebvx46WK355IC8BSYKhA86maU/C5TyOra9y/oS07E=; b=oZnPYlaZFuWaQpPkn4PZLoU14KF/YoPaT+zSRm+5KRIBeA4WAHBCXGQMyriXzaskQv 8f2G4XUhCfSB+CeAptzioePNIQII8rTvzqrU/gs+a+0QJ0lcl+B+CcEECJduqq/gQcOD ddO2BtzwGkIHd0phwP4kgK4XWHKNSrgfrY5+x6ZGJz8rCHCOUUsQ0bbjDzzdzCK2qoW5 JS1Ec+wHi1ZXWkAcdXwYsDbJJXRHLMVi44MHEzC2dZlI4uENXzugwsk80gbhamXfG5nn lajqaeP7BBCq3pYSVzJ9nGRW9Rkt6zCCIpeUaRS+x5LkLGl8HdJeI8boNpMXW3nmNQc8 kuig== X-Gm-Message-State: AOAM53366xR3CZaUFUlLjdiEoIBekFLg+XjAHfYVXfVHEc1fiNiK5ScO Q75zS59cR+wqHscLJMMp+oBUUQ== X-Google-Smtp-Source: ABdhPJxq53hoH5g966jwbYjUDwfs6lHQ9KOfN5qCJ8fiAFBBjxy/+X2rEoTmF5zSw2rlwmYa8QmuBA== X-Received: by 2002:aa7:9af2:0:b029:198:273c:6be8 with SMTP id y18-20020aa79af20000b0290198273c6be8mr329847pfp.4.1606253566848; Tue, 24 Nov 2020 13:32:46 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id j74sm15845pfd.43.2020.11.24.13.32.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 Nov 2020 13:32:45 -0800 (PST) Date: Tue, 24 Nov 2020 13:32:44 -0800 From: Kees Cook To: James Bottomley Cc: "Gustavo A. R. Silva" , Joe Perches , Jakub Kicinski , alsa-devel@alsa-project.org, linux-atm-general@lists.sourceforge.net, reiserfs-devel@vger.kernel.org, linux-iio@vger.kernel.org, linux-wireless@vger.kernel.org, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Nathan Chancellor , linux-ide@vger.kernel.org, dm-devel@redhat.com, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, GR-everest-linux-l2@marvell.com, wcn36xx@lists.infradead.org, samba-technical@lists.samba.org, linux-i3c@lists.infradead.org, linux1394-devel@lists.sourceforge.net, linux-afs@lists.infradead.org, usb-storage@lists.one-eyed-alien.net, drbd-dev@lists.linbit.com, devel@driverdev.osuosl.org, linux-cifs@vger.kernel.org, rds-devel@oss.oracle.com, Nick Desaulniers , linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org, oss-drivers@netronome.com, bridge@lists.linux-foundation.org, linux-security-module@vger.kernel.org, amd-gfx@lists.freedesktop.org, linux-stm32@st-md-mailman.stormreply.com, cluster-devel@redhat.com, linux-acpi@vger.kernel.org, coreteam@netfilter.org, intel-wired-lan@lists.osuosl.org, linux-input@vger.kernel.org, Miguel Ojeda , tipc-discussion@lists.sourceforge.net, linux-ext4@vger.kernel.org, linux-media@vger.kernel.org, linux-watchdog@vger.kernel.org, selinux@vger.kernel.org, linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-geode@lists.infradead.org, linux-can@vger.kernel.org, linux-block@vger.kernel.org, linux-gpio@vger.kernel.org, op-tee@lists.trustedfirmware.org, linux-mediatek@lists.infradead.org, xen-devel@lists.xenproject.org, nouveau@lists.freedesktop.org, linux-hams@vger.kernel.org, ceph-devel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-hwmon@vger.kernel.org, x86@kernel.org, linux-nfs@vger.kernel.org, GR-Linux-NIC-Dev@marvell.com, linux-mm@kvack.org, netdev@vger.kernel.org, linux-decnet-user@lists.sourceforge.net, linux-mmc@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-sctp@vger.kernel.org, linux-usb@vger.kernel.org, netfilter-devel@vger.kernel.org, linux-crypto@vger.kernel.org, patches@opensource.cirrus.com, linux-integrity@vger.kernel.org, target-devel@vger.kernel.org, linux-hardening@vger.kernel.org, Jonathan Cameron , Greg KH Subject: Re: [Intel-wired-lan] [PATCH 000/141] Fix fall-through warnings for Clang Message-ID: <202011241327.BB28F12F6@keescook> References: <202011201129.B13FDB3C@keescook> <20201120115142.292999b2@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202011220816.8B6591A@keescook> <9b57fd4914b46f38d54087d75e072d6e947cb56d.camel@HansenPartnership.com> <0147972a72bc13f3629de8a32dee6f1f308994b5.camel@HansenPartnership.com> <20201123130348.GA3119@embeddedor> <8f5611bb015e044fa1c0a48147293923c2d904e4.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8f5611bb015e044fa1c0a48147293923c2d904e4.camel@HansenPartnership.com> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Nov 23, 2020 at 08:31:30AM -0800, James Bottomley wrote: > Really, no ... something which produces no improvement has no value at > all ... we really shouldn't be wasting maintainer time with it because > it has a cost to merge. I'm not sure we understand where the balance > lies in value vs cost to merge but I am confident in the zero value > case. What? We can't measure how many future bugs aren't introduced because the kernel requires explicit case flow-control statements for all new code. We already enable -Wimplicit-fallthrough globally, so that's not the discussion. The issue is that Clang is (correctly) even more strict than GCC for this, so these are the remaining ones to fix for full Clang coverage too. People have spent more time debating this already than it would have taken to apply the patches. :) This is about robustness and language wrangling. It's a big code-base, and this is the price of our managing technical debt for permanent robustness improvements. (The numbers I ran from Gustavo's earlier patches were that about 10% of the places adjusted were identified as legitimate bugs being fixed. This final series may be lower, but there are still bugs being found from it -- we need to finish this and shut the door on it for good.) -- Kees Cook