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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2809EC433EF for ; Sun, 27 Feb 2022 21:29:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231842AbiB0V3j (ORCPT ); Sun, 27 Feb 2022 16:29:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229549AbiB0V3h (ORCPT ); Sun, 27 Feb 2022 16:29:37 -0500 Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 52F584BFDB; Sun, 27 Feb 2022 13:28:59 -0800 (PST) Received: from mail-wm1-f52.google.com ([209.85.128.52]) by mrelayeu.kundenserver.de (mreue009 [213.165.67.97]) with ESMTPSA (Nemesis) id 1MaIvV-1nlAWC1tuH-00WHCz; Sun, 27 Feb 2022 22:28:57 +0100 Received: by mail-wm1-f52.google.com with SMTP id v2-20020a7bcb42000000b0037b9d960079so4764783wmj.0; Sun, 27 Feb 2022 13:28:57 -0800 (PST) X-Gm-Message-State: AOAM532Yh0EM/vUi3XrRrspMDFAX2SaJ5rv7tdetecnYVjti06tDdWFO SH4Tvha2ueTqxdoi4bWFQM5ZpyECPT48oZb8Ix0= X-Google-Smtp-Source: ABdhPJzPpJK3kNFeFtCRMNEMS0Me6SFTBXzOWyPSNiCvLYylg14xxS+eF0Aj0iTsHF8iMxcR3IMA0ji5lT283orHBm0= X-Received: by 2002:a05:600c:4f8e:b0:381:6de4:fccc with SMTP id n14-20020a05600c4f8e00b003816de4fcccmr442954wmq.82.1645997337125; Sun, 27 Feb 2022 13:28:57 -0800 (PST) MIME-Version: 1.0 References: <20220217184829.1991035-1-jakobkoschel@gmail.com> <20220217184829.1991035-4-jakobkoschel@gmail.com> <6DFD3D91-B82C-469C-8771-860C09BD8623@gmail.com> <20220226124249.GU614@gate.crashing.org> <20220227010956.GW614@gate.crashing.org> In-Reply-To: <20220227010956.GW614@gate.crashing.org> From: Arnd Bergmann Date: Sun, 27 Feb 2022 22:28:41 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC PATCH 03/13] usb: remove the usage of the list iterator after the loop To: Segher Boessenkool Cc: Arnd Bergmann , Linus Torvalds , Jakob , Linux Kernel Mailing List , linux-arch , Greg Kroah-Hartman , Thomas Gleixner , Andy Shevchenko , Andrew Morton , Kees Cook , Mike Rapoport , "Gustavo A. R. Silva" , Brian Johannesmeyer , Cristiano Giuffrida , "Bos, H.J." Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:ciFczsxT+CkOslJ2l0u6JWGBxbS4E0kMNdAbJTITFYATBX0CNY2 7+AncTxqmDLOwHEmCgBAUSM4aZJ94QW7o94x4sG/Exo+a/3yH3UynluzSL8WE0Q7Ryykbeh U4U/Uvp21ZFndObDj62+2BzyVnp58UAEMZ8xHlSXfA3O7T1ZzMsKegffhGe3EQdziId/cOx GDhtYvmjUydW/4Tzfc84w== X-UI-Out-Filterresults: notjunk:1;V03:K0:41G5XSrR0U0=:gBsDSllfoD+0ibXraVqNyP kJjWSAvD2hKOfVjLs9CRKkacECdySQjOxpVjft8KH4KvMgsh46wS3pzgjtX6Ph4KegHnmQdWc GffFcsPLAg96Npv+LNkXad9BKE3IRfJDXwk6K/+saBMYf2DBl/NX4X9+kVj4pWvBqm3XlgSEQ SVipWz6hBhfdex9J7KzA8IM7t7eHCoiYMNEQ2uZfHGsysToRqnJzQODFWmS4fOTdyxaLDNfVo dJK+2dpccs+SA56Rjszlb7Z1gQ83X4t3rcLn/03pYbumtiNisVOD+d+OY0jB29Rd9vvxqqxwg KeUXPUWsqV13Z6yUZcUg26t10sVEZCz2CUBOzzQcugLXPo3q4rU3N5czJ2ecgfNQVdfws+bPh 5KE11bZW0Fpg5Ckt5PJvGqWkJMqBTqOzavSXoCcPUcj5apqh4yMUJvtrx4S3vcDjt4KFHoozk qbcvtCEwNGZjTeA/RCX4LA3Z8HNi7u89KgQ2F9I5nD0cSkdJe6tZuHSyJtlK4S7fBZrHaagXI 1UL6SdJwViVICwSccjTQFUeEsLLZx45To6XD6cfeofgUHc0Ql6A3M35gzm1hyJy2qdu6+JdE0 fN/dAEcvVh5FQTyDubi2hmjA9lcDqr89j27mC9jgEp70KsDt25fR/dtB1a3h+1dfNM01KIv1D R2vFWO47yLKp0Btc/jNJxGCKnAaamQ9WC56lWxr5pnHzBvCqUPq+dxAfOhUsZGDF2nC0= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Feb 27, 2022 at 2:09 AM Segher Boessenkool wrote: > > So imo we should just never do this by default, not just if the nasty > -fwrapv or nastier -fno-strict-overflow is used, just like we suggest > in our own documentation. The only valid reason -Wshift-negative-value > is in -Wextra is it warns for situations that always are undefined > behaviour (even if not in GCC). Ok, I just realized that this is specific to the i915 driver because that, unlike most of the kernel builds with -Wextra by default. -Wextra is enabled when users ask for a 'make W=1' build in linux, and i915 is one of just three drivers that enable an equivalent set of warnings, the other ones being greybus and btrfs. This means to work around the extra warnings, we also just need to disable it in the W=1 part of scripts/Makefile.extrawarn, as well as the three drivers that copy those options, but not the default warnings that don't include them. > Could you open a GCC PR for this? The current situation is quite > suboptimal, and what we document as our implementation choice is much > more useful! I hope I managed to capture the issue in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104711 Arnd