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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 B387BC433E3 for ; Thu, 16 Jul 2020 21:08:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8BD3E207DD for ; Thu, 16 Jul 2020 21:08:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726970AbgGPVIP (ORCPT ); Thu, 16 Jul 2020 17:08:15 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:33060 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725959AbgGPVIO (ORCPT ); Thu, 16 Jul 2020 17:08:14 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06GL3Hew187534; Thu, 16 Jul 2020 17:08:06 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 32ax788gna-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 Jul 2020 17:08:06 -0400 Received: from m0098414.ppops.net (m0098414.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 06GL3LO6188037; Thu, 16 Jul 2020 17:08:05 -0400 Received: from ppma06fra.de.ibm.com (48.49.7a9f.ip4.static.sl-reverse.com [159.122.73.72]) by mx0b-001b2d01.pphosted.com with ESMTP id 32ax788gmn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 Jul 2020 17:08:05 -0400 Received: from pps.filterd (ppma06fra.de.ibm.com [127.0.0.1]) by ppma06fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06GL6lTn011429; Thu, 16 Jul 2020 21:08:03 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma06fra.de.ibm.com with ESMTP id 328rbqst6m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 Jul 2020 21:08:03 +0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06GL80vd54198472 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 Jul 2020 21:08:00 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 80CECAE053; Thu, 16 Jul 2020 21:08:00 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 541C9AE051; Thu, 16 Jul 2020 21:07:57 +0000 (GMT) Received: from [9.102.2.181] (unknown [9.102.2.181]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 16 Jul 2020 21:07:57 +0000 (GMT) From: Hari Bathini Subject: Re: [PATCH v3 10/12] ppc64/kexec_file: prepare elfcore header for crashing kernel To: Thiago Jung Bauermann Cc: 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 References: <159466074408.24747.10036072269371204890.stgit@hbathini.in.ibm.com> <159466098739.24747.5860501703617893464.stgit@hbathini.in.ibm.com> <87tuy88ai7.fsf@morokweng.localdomain> Message-ID: <929db6fe-b221-a514-8ea1-93227f8d47b0@linux.ibm.com> Date: Fri, 17 Jul 2020 02:37:56 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <87tuy88ai7.fsf@morokweng.localdomain> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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 bulkscore=0 adultscore=0 spamscore=100 priorityscore=1501 mlxscore=100 mlxlogscore=-1000 phishscore=0 lowpriorityscore=0 clxscore=1015 malwarescore=0 suspectscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007160140 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/07/20 7:52 am, Thiago Jung Bauermann wrote: > > Hari Bathini writes: > >> /** >> + * get_crash_memory_ranges - Get crash memory ranges. This list includes >> + * first/crashing kernel's memory regions that >> + * would be exported via an elfcore. >> + * @mem_ranges: Range list to add the memory ranges to. >> + * >> + * Returns 0 on success, negative errno on error. >> + */ >> +static int get_crash_memory_ranges(struct crash_mem **mem_ranges) >> +{ >> + struct memblock_region *reg; >> + struct crash_mem *tmem; >> + int ret; >> + >> + for_each_memblock(memory, reg) { >> + u64 base, size; >> + >> + base = (u64)reg->base; >> + size = (u64)reg->size; >> + >> + /* Skip backup memory region, which needs a separate entry */ >> + if (base == BACKUP_SRC_START) { >> + if (size > BACKUP_SRC_SIZE) { >> + base = BACKUP_SRC_END + 1; >> + size -= BACKUP_SRC_SIZE; >> + } else >> + continue; >> + } >> + >> + ret = add_mem_range(mem_ranges, base, size); >> + if (ret) >> + goto out; >> + >> + /* Try merging adjacent ranges before reallocation attempt */ >> + if ((*mem_ranges)->nr_ranges == (*mem_ranges)->max_nr_ranges) >> + sort_memory_ranges(*mem_ranges, true); >> + } >> + >> + /* Reallocate memory ranges if there is no space to split ranges */ >> + tmem = *mem_ranges; >> + if (tmem && (tmem->nr_ranges == tmem->max_nr_ranges)) { >> + tmem = realloc_mem_ranges(mem_ranges); >> + if (!tmem) >> + goto out; >> + } >> + >> + /* Exclude crashkernel region */ >> + ret = crash_exclude_mem_range(tmem, crashk_res.start, crashk_res.end); >> + if (ret) >> + goto out; >> + >> + ret = add_rtas_mem_range(mem_ranges); >> + if (ret) >> + goto out; >> + >> + ret = add_opal_mem_range(mem_ranges); >> + if (ret) >> + goto out; > > Maybe I'm confused, but don't you add the RTAS and OPAL regions as > usable memory for the crashkernel? In that case they shouldn't show up > in the core file. kexec-tools does the same thing. I am not endorsing it but I was trying to stay in parity to avoid breaking any userspace tools/commands. But as you rightly pointed, this is NOT right. The right thing to do, to get the rtas/opal data at the time of crash, is to have a backup region for them just like we have for the first 64K memory. I was hoping to do that later. Will check how userspace tools respond to dropping these regions. If that makes the tools unhappy, will retain the regions with a FIXME. Sorry about the confusion. Thanks Hari 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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 35DEFC433E2 for ; Thu, 16 Jul 2020 21:11:02 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 83EDB20760 for ; Thu, 16 Jul 2020 21:11:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 83EDB20760 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; 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Thu, 16 Jul 2020 17:08:05 -0400 Received: from ppma06fra.de.ibm.com (48.49.7a9f.ip4.static.sl-reverse.com [159.122.73.72]) by mx0b-001b2d01.pphosted.com with ESMTP id 32ax788gmn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 Jul 2020 17:08:05 -0400 Received: from pps.filterd (ppma06fra.de.ibm.com [127.0.0.1]) by ppma06fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06GL6lTn011429; Thu, 16 Jul 2020 21:08:03 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma06fra.de.ibm.com with ESMTP id 328rbqst6m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 Jul 2020 21:08:03 +0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06GL80vd54198472 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 Jul 2020 21:08:00 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 80CECAE053; Thu, 16 Jul 2020 21:08:00 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 541C9AE051; Thu, 16 Jul 2020 21:07:57 +0000 (GMT) Received: from [9.102.2.181] (unknown [9.102.2.181]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 16 Jul 2020 21:07:57 +0000 (GMT) From: Hari Bathini Subject: Re: [PATCH v3 10/12] ppc64/kexec_file: prepare elfcore header for crashing kernel To: Thiago Jung Bauermann References: <159466074408.24747.10036072269371204890.stgit@hbathini.in.ibm.com> <159466098739.24747.5860501703617893464.stgit@hbathini.in.ibm.com> <87tuy88ai7.fsf@morokweng.localdomain> Message-ID: <929db6fe-b221-a514-8ea1-93227f8d47b0@linux.ibm.com> Date: Fri, 17 Jul 2020 02:37:56 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <87tuy88ai7.fsf@morokweng.localdomain> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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 bulkscore=0 adultscore=0 spamscore=100 priorityscore=1501 mlxscore=100 mlxlogscore=-1000 phishscore=0 lowpriorityscore=0 clxscore=1015 malwarescore=0 suspectscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007160140 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Pingfan Liu , Petr Tesarik , Nayna Jain , Kexec-ml , Mahesh J Salgaonkar , Mimi Zohar , lkml , linuxppc-dev , Sourabh Jain , Andrew Morton , Dave Young , Vivek Goyal , Eric Biederman Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 16/07/20 7:52 am, Thiago Jung Bauermann wrote: > > Hari Bathini writes: > >> /** >> + * get_crash_memory_ranges - Get crash memory ranges. This list includes >> + * first/crashing kernel's memory regions that >> + * would be exported via an elfcore. >> + * @mem_ranges: Range list to add the memory ranges to. >> + * >> + * Returns 0 on success, negative errno on error. >> + */ >> +static int get_crash_memory_ranges(struct crash_mem **mem_ranges) >> +{ >> + struct memblock_region *reg; >> + struct crash_mem *tmem; >> + int ret; >> + >> + for_each_memblock(memory, reg) { >> + u64 base, size; >> + >> + base = (u64)reg->base; >> + size = (u64)reg->size; >> + >> + /* Skip backup memory region, which needs a separate entry */ >> + if (base == BACKUP_SRC_START) { >> + if (size > BACKUP_SRC_SIZE) { >> + base = BACKUP_SRC_END + 1; >> + size -= BACKUP_SRC_SIZE; >> + } else >> + continue; >> + } >> + >> + ret = add_mem_range(mem_ranges, base, size); >> + if (ret) >> + goto out; >> + >> + /* Try merging adjacent ranges before reallocation attempt */ >> + if ((*mem_ranges)->nr_ranges == (*mem_ranges)->max_nr_ranges) >> + sort_memory_ranges(*mem_ranges, true); >> + } >> + >> + /* Reallocate memory ranges if there is no space to split ranges */ >> + tmem = *mem_ranges; >> + if (tmem && (tmem->nr_ranges == tmem->max_nr_ranges)) { >> + tmem = realloc_mem_ranges(mem_ranges); >> + if (!tmem) >> + goto out; >> + } >> + >> + /* Exclude crashkernel region */ >> + ret = crash_exclude_mem_range(tmem, crashk_res.start, crashk_res.end); >> + if (ret) >> + goto out; >> + >> + ret = add_rtas_mem_range(mem_ranges); >> + if (ret) >> + goto out; >> + >> + ret = add_opal_mem_range(mem_ranges); >> + if (ret) >> + goto out; > > Maybe I'm confused, but don't you add the RTAS and OPAL regions as > usable memory for the crashkernel? In that case they shouldn't show up > in the core file. kexec-tools does the same thing. I am not endorsing it but I was trying to stay in parity to avoid breaking any userspace tools/commands. But as you rightly pointed, this is NOT right. The right thing to do, to get the rtas/opal data at the time of crash, is to have a backup region for them just like we have for the first 64K memory. I was hoping to do that later. Will check how userspace tools respond to dropping these regions. If that makes the tools unhappy, will retain the regions with a FIXME. Sorry about the confusion. Thanks Hari