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 59D0BC433F5 for ; Tue, 1 Mar 2022 17:58:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236769AbiCAR6y (ORCPT ); Tue, 1 Mar 2022 12:58:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231947AbiCAR6t (ORCPT ); Tue, 1 Mar 2022 12:58:49 -0500 Received: from new3-smtp.messagingengine.com (new3-smtp.messagingengine.com [66.111.4.229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D310F3CA7B; Tue, 1 Mar 2022 09:58:06 -0800 (PST) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailnew.nyi.internal (Postfix) with ESMTP id 1F34E5801D0; Tue, 1 Mar 2022 12:58:06 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Tue, 01 Mar 2022 12:58:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h=cc :cc:content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to; s=fm3; bh=1b8nHfrBOcjPGYcB+Q6wr00uk1GmKX3v3ZNCnj 2Fc4I=; b=ZBUT+xBEPIHuw8jHImLNH+x52gankwE7MJd8sDFwnEoy45z1BwbhNh xKsOdQ1yD9u7q0d/6DIUtrg535wnOmT4Lvdd1apo2YuuhLLDVkYx1vSgNyoTE5fJ ofsW7j8uCMJyXK6Loz8rrLOzHyzxWsYiemruNwAl4gNUMe4M/NVtyIVhNAgsOfjy b/w/wzWa4VwoEUleGhkhNF3kRyKpQ3Usq/8Ca14buwUMr/k/0v+gPaqGXYzqUKuv KllGIGlPN88CAydfwqCLzM8aK7V+EiOvYiI4kF7OI9OB3TO949n6Hy8EMtjF8IqZ MBlpj07s0Rnbq4GNXj6M7/3IgLXdvpRA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=1b8nHfrBOcjPGYcB+ Q6wr00uk1GmKX3v3ZNCnj2Fc4I=; b=EY31l7G2XfgL9rSC/gwvRf8zFgwtBT7xS zGIS7YVvo/KA/v9LCSJOIARDHfRqiRvn2gTz078tIpwk3oIxG21buWNUxNQmSUyy MyYKa/Xe0zh4/DCiQIRNMfBLOEXackhRaibWR2bFKht/sqIYkVYfZsf6JTqkc8aS N/+KxLe8dnTTbLIJQe4lQN4jxuybvA2M70S25Fv9b7VdN/aPfJftqSYQ4WVfyPqY 0tbQrYevVZ6RBtubRdYtr3gnZBflyWFJSH5G+LkmECZ7pFmQ2xcqosvgp1dXRrwM GXM5n5s+pyNtUs5gG+ueV8296EmUoxyY6tuEcr0WZBCuK4oOvJTLg== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvvddruddtvddguddtgecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpeffhffvuffkfhggtggujgesthdtredttddtvdenucfhrhhomhepifhrvghg ucfmjfcuoehgrhgvgheskhhrohgrhhdrtghomheqnecuggftrfgrthhtvghrnhepveeuhe ejgfffgfeivddukedvkedtleelleeghfeljeeiueeggeevueduudekvdetnecuvehluhhs thgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepghhrvghgsehkrhhorg hhrdgtohhm X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 1 Mar 2022 12:58:03 -0500 (EST) Date: Tue, 1 Mar 2022 18:58:02 +0100 From: Greg KH To: Jakob Koschel Cc: Linus Torvalds , Christian =?iso-8859-1?Q?K=F6nig?= , alsa-devel@alsa-project.org, linux-aspeed@lists.ozlabs.org, "Gustavo A. R. Silva" , linux-iio@vger.kernel.org, nouveau@lists.freedesktop.org, Rasmus Villemoes , dri-devel , Cristiano Giuffrida , amd-gfx list , samba-technical@lists.samba.org, linux1394-devel@lists.sourceforge.net, drbd-dev@lists.linbit.com, linux-arch , CIFS , KVM list , linux-scsi , linux-rdma , linux-staging@lists.linux.dev, "Bos, H.J." , Jason Gunthorpe , intel-wired-lan@lists.osuosl.org, kgdb-bugreport@lists.sourceforge.net, bcm-kernel-feedback-list@broadcom.com, Dan Carpenter , Linux Media Mailing List , Kees Cook , Arnd Bergman , Linux PM , intel-gfx , Brian Johannesmeyer , Nathan Chancellor , linux-fsdevel , Christophe JAILLET , v9fs-developer@lists.sourceforge.net, linux-tegra , Thomas Gleixner , Andy Shevchenko , Linux ARM , linux-sgx@vger.kernel.org, linux-block , Netdev , linux-usb@vger.kernel.org, linux-wireless , Linux Kernel Mailing List , Linux F2FS Dev Mailing List , tipc-discussion@lists.sourceforge.net, Linux Crypto Mailing List , dma , linux-mediatek@lists.infradead.org, Andrew Morton , linuxppc-dev , Mike Rapoport Subject: Re: [PATCH 2/6] treewide: remove using list iterator after loop body as a ptr Message-ID: References: <20220228110822.491923-3-jakobkoschel@gmail.com> <2e4e95d6-f6c9-a188-e1cd-b1eae465562a@amd.com> <4B1AFAD9-C1B3-499C-945A-C259361ABA8C@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B1AFAD9-C1B3-499C-945A-C259361ABA8C@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Tue, Mar 01, 2022 at 06:40:04PM +0100, Jakob Koschel wrote: > > > > On 1. Mar 2022, at 18:36, Greg KH wrote: > > > > On Tue, Mar 01, 2022 at 12:28:15PM +0100, Jakob Koschel wrote: > >> > >> > >>> On 1. Mar 2022, at 01:41, Linus Torvalds wrote: > >>> > >>> On Mon, Feb 28, 2022 at 1:47 PM Jakob Koschel wrote: > >>>> > >>>> The goal of this is to get compiler warnings right? This would indeed be great. > >>> > >>> Yes, so I don't mind having a one-time patch that has been gathered > >>> using some automated checker tool, but I don't think that works from a > >>> long-term maintenance perspective. > >>> > >>> So if we have the basic rule being "don't use the loop iterator after > >>> the loop has finished, because it can cause all kinds of subtle > >>> issues", then in _addition_ to fixing the existing code paths that > >>> have this issue, I really would want to (a) get a compiler warning for > >>> future cases and (b) make it not actually _work_ for future cases. > >>> > >>> Because otherwise it will just happen again. > >>> > >>>> Changing the list_for_each_entry() macro first will break all of those cases > >>>> (e.g. the ones using 'list_entry_is_head()). > >>> > >>> So I have no problems with breaking cases that we basically already > >>> have a patch for due to your automated tool. There were certainly > >>> more than a handful, but it didn't look _too_ bad to just make the > >>> rule be "don't use the iterator after the loop". > >>> > >>> Of course, that's just based on that patch of yours. Maybe there are a > >>> ton of other cases that your patch didn't change, because they didn't > >>> match your trigger case, so I may just be overly optimistic here. > >> > >> Based on the coccinelle script there are ~480 cases that need fixing > >> in total. I'll now finish all of them and then split them by > >> submodules as Greg suggested and repost a patch set per submodule. > >> Sounds good? > > > > Sounds good to me! > > > > If you need help carving these up and maintaining them over time as > > different subsystem maintainers accept/ignore them, just let me know. > > Doing large patchsets like this can be tough without a lot of > > experience. > > Very much appreciated! > > There will probably be some cases that do not match one of the pattern > we already discussed and need separate attention. > > I was planning to start with one subsystem and adjust the coming ones > according to the feedback gather there instead of posting all of them > in one go. That seems wise. Feel free to use USB as a testing ground for this if you want to :) thanks, greg k-h