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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 91EBAC48BD4 for ; Tue, 25 Jun 2019 13:24:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 709F8208CA for ; Tue, 25 Jun 2019 13:24:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729456AbfFYNYa (ORCPT ); Tue, 25 Jun 2019 09:24:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32906 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726707AbfFYNYa (ORCPT ); Tue, 25 Jun 2019 09:24:30 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6E21A3092669; Tue, 25 Jun 2019 13:24:22 +0000 (UTC) Received: from [10.18.17.153] (dhcp-17-153.bos.redhat.com [10.18.17.153]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 92ABC5C238; Tue, 25 Jun 2019 13:24:21 +0000 (UTC) Subject: Re: [PATCH v4 00/10] klp-convert livepatch build tooling To: Miroslav Benes , Petr Mladek Cc: linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, linux-kbuild@vger.kernel.org References: <20190509143859.9050-1-joe.lawrence@redhat.com> <20190614083435.uq3mk6mprbatysol@pathway.suse.cz> From: Joe Lawrence Message-ID: <76da6ab0-5540-d9ff-c5ea-6dc31a39c744@redhat.com> Date: Tue, 25 Jun 2019 09:24:20 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.43]); Tue, 25 Jun 2019 13:24:30 +0000 (UTC) Sender: live-patching-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org On 6/25/19 7:36 AM, Miroslav Benes wrote: > > [ ... snip ... ] > > So I made a couple of experiments and found that GCC is somehow involved. > If klp-convert (from scripts/livepatch/) is compiled with our GCC 4.8.5 > from SLE12, the output is incorrect. If I compile it with GCC 7.4.0 from > openSUSE Leap 15.1, the output is correct. > > If I revert commit d59cadc0a8f8 ("[squash] klp-convert: make > convert_rela() list-safe") (from Joe's expanded github tree), the problem > disappears. > > I haven't spotted any problem in the code and I cannot explain a > dependency on GCC version. Any ideas? > Thanks for revisiting and debugging this. Narrowing it down to my "fix" to convert_rela() should be helpful. In my case, I was probably testing with RHEL-8, which has gcc 8.2 vs RHEL-7 which has gcc 4.8. I'll have to make sure to try with a few different versions for the next round. -- Joe