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 2A5C2C77B75 for ; Wed, 12 Apr 2023 06:15:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229549AbjDLGPB (ORCPT ); Wed, 12 Apr 2023 02:15:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229517AbjDLGO6 (ORCPT ); Wed, 12 Apr 2023 02:14:58 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B87B940F2; Tue, 11 Apr 2023 23:14:50 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5366362E5E; Wed, 12 Apr 2023 06:14:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41DEBC433EF; Wed, 12 Apr 2023 06:14:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681280089; bh=Nxag8wK1torwvwcelmJg4s5Xft+8uu3sHSeDBkA6DIU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Z0C6JC868/IbrDNImk0zmIaQYLikuOeSr4okyyqgL6WyPuWoITU2J28J+4gTwO+SY jFrJtF+QfNU/XlnmM4Nhdsz4nmpnkBZ/+pLXtdK70Z+gdKrDmYTCVTx0pkbmgg884h k5jrVjHTZLUx8nxkSGxiaQnavKN3Whh5Zk7hTVZ8= Date: Wed, 12 Apr 2023 08:14:47 +0200 From: Greg Kroah-Hartman To: John Moon Cc: Masahiro Yamada , Nathan Chancellor , Nick Desaulniers , Nicolas Schier , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, Randy Dunlap , Arnd Bergmann , Bjorn Andersson , Todd Kjos , Matthias Maennich , Giuliano Procida , kernel-team@android.com, libabigail@sourceware.org, Jordan Crouse , Trilok Soni , Satya Durga Srinivasu Prabhala , Elliot Berman , Guru Das Srinagesh Subject: Re: [PATCH v5 1/2] check-uapi: Introduce check-uapi.sh Message-ID: <2023041209-armed-overlaid-3d3d@gregkh> References: <20230407203456.27141-1-quic_johmoo@quicinc.com> <20230407203456.27141-2-quic_johmoo@quicinc.com> <2023041015-lunar-dandelion-1b4e@gregkh> <2023041136-donator-faceplate-5f91@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 11, 2023 at 11:36:48AM -0700, John Moon wrote: > > > > > > Others do not seem to be intentional: > > > > > > Addition/use of flex arrays: > > > - include/uapi/linux/rseq.h (f7b01bb0b57f) > > > - include/uapi/scsi/scsi_bsg_mpi3mr.h (c6f2e6b6eaaf) > > > > That is not a breakage, that's a tool problem. > > > > > Type change: > > > - include/uapi/scsi/scsi_bsg_ufs.h (3f5145a615238) > > > > Again, not a real breakage, size is still the same. > > > > Would you find the tool more useful if it simply filtered out all instances > where the size of the type did not change? This would filter out the > following which the tool currently flags: > > - enum expansions > - reserved field expansions > - expansions of a struct with a flex array at the end > - type changes > - re-ordering of existing members > - ...others? Obviously not, as some of those are real breakages, and some are not at all. Please understand what is an abi breakage. Adding new enums is not. Using a reserved field is not. Reording existing members IS. > These changes aren't _always_ safe, but if you assume the kernel developer > is doing something reasonable, then maybe it's okay. Maybe we could hide > these checks behind something like a "--pedantic" flag? Again, no, that list above has totally different things in it, some are completly safe, others totally break the abi. Do NOT lump them all together as that is wrong. thanks, greg k-h