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=-3.8 required=3.0 tests=BAYES_00, 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 A4034C63777 for ; Sun, 22 Nov 2020 22:55:28 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 61EE820773 for ; Sun, 22 Nov 2020 22:55:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 61EE820773 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=telegraphics.com.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.33538.64614 (Exim 4.92) (envelope-from ) id 1kgyFx-0001vp-BW; Sun, 22 Nov 2020 22:54:53 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 33538.64614; Sun, 22 Nov 2020 22:54:53 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kgyFx-0001vi-8N; Sun, 22 Nov 2020 22:54:53 +0000 Received: by outflank-mailman (input) for mailman id 33538; Sun, 22 Nov 2020 22:54:51 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kgyFv-0001vd-QP for xen-devel@lists.xenproject.org; Sun, 22 Nov 2020 22:54:51 +0000 Received: from kvm5.telegraphics.com.au (unknown [98.124.60.144]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTP id c37dab44-18c0-4949-8564-38411d5c7c86; Sun, 22 Nov 2020 22:54:51 +0000 (UTC) Received: from localhost (localhost.localdomain [127.0.0.1]) by kvm5.telegraphics.com.au (Postfix) with ESMTP id BF98E29DB3; Sun, 22 Nov 2020 17:54:47 -0500 (EST) Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kgyFv-0001vd-QP for xen-devel@lists.xenproject.org; Sun, 22 Nov 2020 22:54:51 +0000 X-Inumbo-ID: c37dab44-18c0-4949-8564-38411d5c7c86 Received: from kvm5.telegraphics.com.au (unknown [98.124.60.144]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTP id c37dab44-18c0-4949-8564-38411d5c7c86; Sun, 22 Nov 2020 22:54:51 +0000 (UTC) Received: from localhost (localhost.localdomain [127.0.0.1]) by kvm5.telegraphics.com.au (Postfix) with ESMTP id BF98E29DB3; Sun, 22 Nov 2020 17:54:47 -0500 (EST) Date: Mon, 23 Nov 2020 09:54:48 +1100 (AEDT) From: Finn Thain To: Miguel Ojeda cc: James Bottomley , Kees Cook , Jakub Kicinski , "Gustavo A. R. Silva" , linux-kernel , alsa-devel@alsa-project.org, amd-gfx@lists.freedesktop.org, bridge@lists.linux-foundation.org, ceph-devel@vger.kernel.org, cluster-devel@redhat.com, coreteam@netfilter.org, devel@driverdev.osuosl.org, dm-devel@redhat.com, drbd-dev@lists.linbit.com, dri-devel@lists.freedesktop.org, GR-everest-linux-l2@marvell.com, GR-Linux-NIC-Dev@marvell.com, intel-gfx@lists.freedesktop.org, intel-wired-lan@lists.osuosl.org, keyrings@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-acpi@vger.kernel.org, linux-afs@lists.infradead.org, Linux ARM , linux-arm-msm@vger.kernel.org, linux-atm-general@lists.sourceforge.net, linux-block@vger.kernel.org, linux-can@vger.kernel.org, linux-cifs@vger.kernel.org, Linux Crypto Mailing List , linux-decnet-user@lists.sourceforge.net, Ext4 Developers List , linux-fbdev@vger.kernel.org, linux-geode@lists.infradead.org, linux-gpio@vger.kernel.org, linux-hams@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-i3c@lists.infradead.org, linux-ide@vger.kernel.org, linux-iio@vger.kernel.org, linux-input , linux-integrity@vger.kernel.org, linux-mediatek@lists.infradead.org, Linux Media Mailing List , linux-mmc@vger.kernel.org, Linux-MM , linux-mtd@lists.infradead.org, linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-scsi@vger.kernel.org, linux-sctp@vger.kernel.org, linux-security-module@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-usb@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-wireless , Network Development , netfilter-devel@vger.kernel.org, nouveau@lists.freedesktop.org, op-tee@lists.trustedfirmware.org, oss-drivers@netronome.com, patches@opensource.cirrus.com, rds-devel@oss.oracle.com, reiserfs-devel@vger.kernel.org, samba-technical@lists.samba.org, selinux@vger.kernel.org, target-devel@vger.kernel.org, tipc-discussion@lists.sourceforge.net, usb-storage@lists.one-eyed-alien.net, virtualization@lists.linux-foundation.org, wcn36xx@lists.infradead.org, "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , xen-devel@lists.xenproject.org, linux-hardening@vger.kernel.org, Nick Desaulniers , Nathan Chancellor , Miguel Ojeda , Joe Perches Subject: Re: [PATCH 000/141] Fix fall-through warnings for Clang In-Reply-To: Message-ID: References: <20201120105344.4345c14e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202011201129.B13FDB3C@keescook> <20201120115142.292999b2@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202011220816.8B6591A@keescook> <9b57fd4914b46f38d54087d75e072d6e947cb56d.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII On Sun, 22 Nov 2020, Miguel Ojeda wrote: > > It isn't that much effort, isn't it? Plus we need to take into account > the future mistakes that it might prevent, too. We should also take into account optimisim about future improvements in tooling. > So even if there were zero problems found so far, it is still a positive > change. > It is if you want to spin it that way. > I would agree if these changes were high risk, though; but they are > almost trivial. > This is trivial: case 1: this(); + fallthrough; case 2: that(); But what we inevitably get is changes like this: case 3: this(); + break; case 4: hmmm(); Why? Mainly to silence the compiler. Also because the patch author argued successfully that they had found a theoretical bug, often in mature code. But is anyone keeping score of the regressions? If unreported bugs count, what about unreported regressions? > Cheers, > Miguel >