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 E8BD3C4332F for ; Wed, 9 Feb 2022 09:49:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229521AbiBIJtR (ORCPT ); Wed, 9 Feb 2022 04:49:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230160AbiBIJtQ (ORCPT ); Wed, 9 Feb 2022 04:49:16 -0500 Received: from out199-14.us.a.mail.aliyun.com (out199-14.us.a.mail.aliyun.com [47.90.199.14]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D91FC001F5C; Wed, 9 Feb 2022 01:49:07 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R341e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04395;MF=tonylu@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0V4-gd1y_1644399828; Received: from localhost(mailfrom:tonylu@linux.alibaba.com fp:SMTPD_---0V4-gd1y_1644399828) by smtp.aliyun-inc.com(127.0.0.1); Wed, 09 Feb 2022 17:43:48 +0800 Date: Wed, 9 Feb 2022 17:43:45 +0800 From: Tony Lu To: "Dmitry V. Levin" Cc: Karsten Graul , kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org, linux-api@vger.kernel.org Subject: Re: [PATCH] Partially revert "net/smc: Add netlink net namespace support" Message-ID: Reply-To: Tony Lu References: <20211228130611.19124-1-tonylu@linux.alibaba.com> <20211228130611.19124-3-tonylu@linux.alibaba.com> <20220131002453.GA7599@altlinux.org> <521e3f2a-8b00-43d4-b296-1253c351a3d2@linux.ibm.com> <20220202030904.GA9742@altlinux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220202030904.GA9742@altlinux.org> Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On Wed, Feb 02, 2022 at 06:09:04AM +0300, Dmitry V. Levin wrote: > The change of sizeof(struct smc_diag_linkinfo) by commit 79d39fc503b4 > ("net/smc: Add netlink net namespace support") introduced an ABI > regression: since struct smc_diag_lgrinfo contains an object of > type "struct smc_diag_linkinfo", offset of all subsequent members > of struct smc_diag_lgrinfo was changed by that change. > > As result, applications compiled with the old version > of struct smc_diag_linkinfo will receive garbage in > struct smc_diag_lgrinfo.role if the kernel implements > this new version of struct smc_diag_linkinfo. > > Fix this regression by reverting the part of commit 79d39fc503b4 that > changes struct smc_diag_linkinfo. After all, there is SMC_GEN_NETLINK > interface which is good enough, so there is probably no need to touch > the smc_diag ABI in the first place. > > Fixes: 79d39fc503b4 ("net/smc: Add netlink net namespace support") > Signed-off-by: Dmitry V. Levin Thank you and Karsten. It was my negligence that caused the ABI incompatibility issue. I will consider to fix it completely. And we are starting to build smc-tools and other userspace test for potential ABI modifications. Best regards, Tony Lu