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 B6A91C2D0E4 for ; Tue, 24 Nov 2020 01:06:23 +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 4F7F120721 for ; Tue, 24 Nov 2020 01:06:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4F7F120721 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=perches.com 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.35319.66779 (Exim 4.92) (envelope-from ) id 1khMmA-0003fx-PN; Tue, 24 Nov 2020 01:05:46 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 35319.66779; Tue, 24 Nov 2020 01:05:46 +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 1khMmA-0003fq-ML; Tue, 24 Nov 2020 01:05:46 +0000 Received: by outflank-mailman (input) for mailman id 35319; Tue, 24 Nov 2020 01:05:45 +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 1khMm9-0003fl-FW for xen-devel@lists.xenproject.org; Tue, 24 Nov 2020 01:05:45 +0000 Received: from smtprelay.hostedemail.com (unknown [216.40.44.133]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 792fb3e0-d08c-41cd-bde2-922febcbc97d; Tue, 24 Nov 2020 01:05:43 +0000 (UTC) Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay08.hostedemail.com (Postfix) with ESMTP id C6794182CED28; Tue, 24 Nov 2020 01:05:42 +0000 (UTC) Received: from XPS-9350.home (unknown [47.151.128.180]) (Authenticated sender: joe@perches.com) by omf04.hostedemail.com (Postfix) with ESMTPA; Tue, 24 Nov 2020 01:05:31 +0000 (UTC) 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 1khMm9-0003fl-FW for xen-devel@lists.xenproject.org; Tue, 24 Nov 2020 01:05:45 +0000 X-Inumbo-ID: 792fb3e0-d08c-41cd-bde2-922febcbc97d Received: from smtprelay.hostedemail.com (unknown [216.40.44.133]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 792fb3e0-d08c-41cd-bde2-922febcbc97d; Tue, 24 Nov 2020 01:05:43 +0000 (UTC) Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay08.hostedemail.com (Postfix) with ESMTP id C6794182CED28; Tue, 24 Nov 2020 01:05:42 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: sea70_4d178da27369 X-Filterd-Recvd-Size: 4565 Received: from XPS-9350.home (unknown [47.151.128.180]) (Authenticated sender: joe@perches.com) by omf04.hostedemail.com (Postfix) with ESMTPA; Tue, 24 Nov 2020 01:05:31 +0000 (UTC) Message-ID: Subject: Re: [PATCH 000/141] Fix fall-through warnings for Clang From: Joe Perches To: Finn Thain , 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 Date: Mon, 23 Nov 2020 17:05:30 -0800 In-Reply-To: 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> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.38.1-1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit On Tue, 2020-11-24 at 11:58 +1100, Finn Thain wrote: > it's not for me to prove that such patches don't affect code > generation. That's for the patch author and (unfortunately) for reviewers. Ideally, that proof would be provided by the compilation system itself and not patch authors nor reviewers nor maintainers. Unfortunately gcc does not guarantee repeatability or deterministic output. To my knowledge, neither does clang.