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=-9.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 0F9DDC433DF for ; Sun, 26 Jul 2020 19:40:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E093A206D8 for ; Sun, 26 Jul 2020 19:40:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727996AbgGZTkx (ORCPT ); Sun, 26 Jul 2020 15:40:53 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:55554 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726144AbgGZTkx (ORCPT ); Sun, 26 Jul 2020 15:40:53 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06QJWur7016931; Sun, 26 Jul 2020 15:40:38 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 32gg1sfwqj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 26 Jul 2020 15:40:38 -0400 Received: from m0098409.ppops.net (m0098409.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 06QJYAqh018463; Sun, 26 Jul 2020 15:40:38 -0400 Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 32gg1sfwpt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 26 Jul 2020 15:40:38 -0400 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06QJZq39028242; Sun, 26 Jul 2020 19:40:36 GMT Received: from b06avi18626390.portsmouth.uk.ibm.com (b06avi18626390.portsmouth.uk.ibm.com [9.149.26.192]) by ppma04ams.nl.ibm.com with ESMTP id 32gcy4heut-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 26 Jul 2020 19:40:35 +0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06QJd8RW60424566 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 26 Jul 2020 19:39:08 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 164B7A4053; Sun, 26 Jul 2020 19:40:33 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C9787A4057; Sun, 26 Jul 2020 19:40:29 +0000 (GMT) Received: from [192.168.0.8] (unknown [9.85.82.224]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Sun, 26 Jul 2020 19:40:29 +0000 (GMT) Subject: [RESEND PATCH v5 11/11] ppc64/kexec_file: fix kexec load failure with lack of memory hole From: Hari Bathini To: Michael Ellerman , Andrew Morton Cc: Pingfan Liu , Thiago Jung Bauermann , Mahesh J Salgaonkar , Sourabh Jain , Vivek Goyal , Dave Young , Petr Tesarik , Pingfan Liu , linuxppc-dev , Kexec-ml , lkml , Pingfan Liu , Eric Biederman , Thiago Jung Bauermann , Mimi Zohar , Nayna Jain Date: Mon, 27 Jul 2020 01:10:28 +0530 Message-ID: <159579242226.5790.13933486642004084417.stgit@hbathini> In-Reply-To: <159579157320.5790.6748078824637688685.stgit@hbathini> References: <159579157320.5790.6748078824637688685.stgit@hbathini> User-Agent: StGit/0.21 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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=2020-07-26_12:2020-07-24,2020-07-26 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 spamscore=0 adultscore=0 clxscore=1015 impostorscore=0 lowpriorityscore=0 phishscore=0 priorityscore=1501 malwarescore=0 mlxscore=0 bulkscore=0 suspectscore=2 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007260154 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kexec purgatory has to run in real mode. Only the first memory block maybe accessible in real mode. And, unlike the case with panic kernel, no memory is set aside for regular kexec load. Another thing to note is, the memory for crashkernel is reserved at an offset of 128MB. So, when crashkernel memory is reserved, the memory ranges to load kexec segments shrink further as the generic code only looks for memblock free memory ranges and in all likelihood only a tiny bit of memory from 0 to 128MB would be available to load kexec segments. With kdump being used by default in general, kexec file load is likely to fail almost always. This can be fixed by changing the memory hole lookup logic for regular kexec to use the same method as kdump. This would mean that most kexec segments will overlap with crashkernel memory region. That should still be ok as the pages, whose destination address isn't available while loading, are placed in an intermediate location till a flush to the actual destination address happens during kexec boot sequence. Signed-off-by: Hari Bathini Tested-by: Pingfan Liu Reviewed-by: Thiago Jung Bauermann --- v4 -> v5: * Unchanged. v3 -> v4: * Unchanged. Added Reviewed-by tag from Thiago. v2 -> v3: * Unchanged. Added Tested-by tag from Pingfan. v1 -> v2: * New patch to fix locating memory hole for kexec_file_load (kexec -s -l) when memory is reserved for crashkernel. arch/powerpc/kexec/file_load_64.c | 33 ++++++++++++++------------------- 1 file changed, 14 insertions(+), 19 deletions(-) diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c index 296be7fc6440..7933b8990714 100644 --- a/arch/powerpc/kexec/file_load_64.c +++ b/arch/powerpc/kexec/file_load_64.c @@ -1122,13 +1122,6 @@ int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf) u64 buf_min, buf_max; int ret; - /* - * Use the generic kexec_locate_mem_hole for regular - * kexec_file_load syscall - */ - if (kbuf->image->type != KEXEC_TYPE_CRASH) - return kexec_locate_mem_hole(kbuf); - /* Look up the exclude ranges list while locating the memory hole */ emem = &(kbuf->image->arch.exclude_ranges); if (!(*emem) || ((*emem)->nr_ranges == 0)) { @@ -1136,11 +1129,15 @@ int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf) return kexec_locate_mem_hole(kbuf); } + buf_min = kbuf->buf_min; + buf_max = kbuf->buf_max; /* Segments for kdump kernel should be within crashkernel region */ - buf_min = (kbuf->buf_min < crashk_res.start ? - crashk_res.start : kbuf->buf_min); - buf_max = (kbuf->buf_max > crashk_res.end ? - crashk_res.end : kbuf->buf_max); + if (kbuf->image->type == KEXEC_TYPE_CRASH) { + buf_min = (buf_min < crashk_res.start ? + crashk_res.start : buf_min); + buf_max = (buf_max > crashk_res.end ? + crashk_res.end : buf_max); + } if (buf_min > buf_max) { pr_err("Invalid buffer min and/or max values\n"); @@ -1177,15 +1174,13 @@ int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf) int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len) { - if (image->type == KEXEC_TYPE_CRASH) { - int ret; + int ret; - /* Get exclude memory ranges needed for setting up kdump segments */ - ret = get_exclude_memory_ranges(&(image->arch.exclude_ranges)); - if (ret) { - pr_err("Failed to setup exclude memory ranges for buffer lookup\n"); - return ret; - } + /* Get exclude memory ranges needed for setting up kexec segments */ + ret = get_exclude_memory_ranges(&(image->arch.exclude_ranges)); + if (ret) { + pr_err("Failed to setup exclude memory ranges for buffer lookup\n"); + return ret; } return kexec_image_probe_default(image, buf, buf_len);