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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 AAA1DC433E0 for ; Thu, 16 Jul 2020 22:12:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89A97207FB for ; Thu, 16 Jul 2020 22:12:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726599AbgGPWMY (ORCPT ); Thu, 16 Jul 2020 18:12:24 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:11950 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726007AbgGPWMX (ORCPT ); Thu, 16 Jul 2020 18:12:23 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06GM0lYH105928; Thu, 16 Jul 2020 18:12:13 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 32as6du8bg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 Jul 2020 18:12:13 -0400 Received: from m0098419.ppops.net (m0098419.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 06GM14ab107297; Thu, 16 Jul 2020 18:12:13 -0400 Received: from ppma01wdc.us.ibm.com (fd.55.37a9.ip4.static.sl-reverse.com [169.55.85.253]) by mx0b-001b2d01.pphosted.com with ESMTP id 32as6du8b5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 Jul 2020 18:12:13 -0400 Received: from pps.filterd (ppma01wdc.us.ibm.com [127.0.0.1]) by ppma01wdc.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06GM5LZh016382; Thu, 16 Jul 2020 22:12:12 GMT Received: from b03cxnp08028.gho.boulder.ibm.com (b03cxnp08028.gho.boulder.ibm.com [9.17.130.20]) by ppma01wdc.us.ibm.com with ESMTP id 32752943wk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 Jul 2020 22:12:12 +0000 Received: from b03ledav004.gho.boulder.ibm.com (b03ledav004.gho.boulder.ibm.com [9.17.130.235]) by b03cxnp08028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06GMCB011049228 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 Jul 2020 22:12:11 GMT Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2B8F77809F; Thu, 16 Jul 2020 22:12:11 +0000 (GMT) Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C156B7809C; Thu, 16 Jul 2020 22:12:07 +0000 (GMT) Received: from morokweng.localdomain (unknown [9.163.8.110]) by b03ledav004.gho.boulder.ibm.com (Postfix) with ESMTPS; Thu, 16 Jul 2020 22:12:07 +0000 (GMT) References: <159466074408.24747.10036072269371204890.stgit@hbathini.in.ibm.com> <159466093748.24747.4655547403463921814.stgit@hbathini.in.ibm.com> <871rlc9upc.fsf@morokweng.localdomain> <6f64a18a-352e-fdec-c902-45aefc31cc0a@linux.ibm.com> User-agent: mu4e 1.2.0; emacs 26.3 From: Thiago Jung Bauermann To: Hari Bathini Cc: kernel test robot , Pingfan Liu , Nayna Jain , Kexec-ml , Mahesh J Salgaonkar , Mimi Zohar , lkml , linuxppc-dev , Sourabh Jain , Petr Tesarik , Andrew Morton , Dave Young , Vivek Goyal , Eric Biederman Subject: Re: [PATCH v3 07/12] ppc64/kexec_file: add support to relocate purgatory In-reply-to: <6f64a18a-352e-fdec-c902-45aefc31cc0a@linux.ibm.com> Date: Thu, 16 Jul 2020 19:12:04 -0300 Message-ID: <87365rcdor.fsf@morokweng.localdomain> MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-07-16_11:2020-07-16,2020-07-16 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_spam_definite policy=outbound score=100 lowpriorityscore=0 adultscore=0 clxscore=1015 suspectscore=0 mlxscore=100 bulkscore=0 malwarescore=0 priorityscore=1501 impostorscore=0 phishscore=0 spamscore=100 mlxlogscore=-1000 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007160142 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hari Bathini writes: > On 16/07/20 5:50 am, Thiago Jung Bauermann wrote: >> >> Hari Bathini writes: >> >>> So, add support to relocate purgatory in kexec_file_load system call >>> by setting up TOC pointer and applying RELA relocations as needed. >> >> If we do want to use a C purgatory, Michael Ellerman had suggested >> building it as a Position Independent Executable, which greatly reduces >> the number and types of relocations that are needed. See patches 4 and 9 >> here: >> >> https://lore.kernel.org/linuxppc-dev/1478748449-3894-1-git-send-email-bauerman@linux.vnet.ibm.com/ >> >> In the series above I hadn't converted x86 to PIE. If I had done that, >> possibly Dave Young's opinion would have been different. :-) >> >> If that's still not desirable, he suggested in that discussion lifting >> some code from x86 to generic code, which I implemented and would >> simplify this patch as well: >> >> https://lore.kernel.org/linuxppc-dev/5009580.5GxAkTrMYA@morokweng/ >> > > Agreed. But I prefer to work on PIE and/or moving common relocation_add code > for x86 & s390 to generic code later when I try to build on these purgatory > changes. So, a separate series later to rework purgatory with the things you > mentioned above sounds ok? Sounds ok to me. Let's see what the maintainers think, then. -- Thiago Jung Bauermann IBM Linux Technology Center