From patchwork Tue Apr 4 18:03:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric DeVolder X-Patchwork-Id: 79317 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b0ea:0:b0:3b6:4342:cba0 with SMTP id b10csp75329vqo; Tue, 4 Apr 2023 11:19:13 -0700 (PDT) X-Google-Smtp-Source: AKy350bAE8KUnG50Si5nUcwmhwSk9COylfQvEH75I3pq7gU+fB4O7ne3hp+DzU/YgBXw3nxiC11x X-Received: by 2002:a17:902:e891:b0:1a1:f413:70b1 with SMTP id w17-20020a170902e89100b001a1f41370b1mr4067026plg.18.1680632353389; Tue, 04 Apr 2023 11:19:13 -0700 (PDT) ARC-Seal: i=2; a=rsa-sha256; t=1680632353; cv=pass; d=google.com; s=arc-20160816; b=f1C1vXETBqCJi9zIa0ftFe7bV+x5ezRlQLjWHR/SwPwGW5lvzi7p60kUYHr1lD7TWe 60MWzF3KAAlAO4D8XQK+5AyyVI9oNQMpLLyYmufwFfnUgKGBZLmWDv/9LdmvTOBGtF/6 m3ELlHRSdj1HO5TcxSBeI87oxVWc9uieDW8SP0+EnNooIg54QAf6cNlNCD3P3/hMfw57 MYvO4wW9N6dZ6CH4sOuOZfwPazki4rf8oQI+qhwDuD+kHjCow/+FNlbThFkXs2aL8xMU NNFCqhdBEIe39ninCx26G3vMxOFDqkP2AWkkuF4YXp/zK3+ERneo/788ptQPUZpxOx7I Xh0w== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:content-transfer-encoding :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:dkim-signature; bh=vQVFlom304Zmzd+iNcoZIdmjn9O6Eur26Ibd7OK8M/Q=; b=UcbqEdbiw9S6FJq/5dCvVZCqpbVj71g24WCH/dYJh36HTLZJhc+0cliUTFtkBMaWUg yuA+m8lGr1N1mil8VfjT20vW5xFsSDVxgT+hyxzNi8J5Cb+MPq9NME4cxksLThDWrAI3 iusKnn7N9YS4DpOFP8PdeH0oOsmU2fgjQrNQ+160EySTQTghVAPTxoufh1Dd2chp9Lj3 GaBcUYI+5Yw/LJQs+hQchNxMODD65DT+IxNuTShuUnja5YgqnDbGg6CGrTgNIaX8xDwg B0Ektipc6zJhuhvB6pdl731w+Gas+g4gKj/0xA2Sr98k0akLaKDtmBdALabKuxSYoAVg 9PVg== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2022-7-12 header.b=nHamcrV5; dkim=pass header.i=@oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=c9tXgCvA; arc=pass (i=1 spf=pass spfdomain=oracle.com dkim=pass dkdomain=oracle.com dmarc=pass fromdomain=oracle.com); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id s24-20020a170902a51800b001a1def4a04bsi10391603plq.375.2023.04.04.11.19.00; Tue, 04 Apr 2023 11:19:13 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2022-7-12 header.b=nHamcrV5; dkim=pass header.i=@oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=c9tXgCvA; arc=pass (i=1 spf=pass spfdomain=oracle.com dkim=pass dkdomain=oracle.com dmarc=pass fromdomain=oracle.com); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236318AbjDDSFF (ORCPT + 99 others); Tue, 4 Apr 2023 14:05:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236322AbjDDSEt (ORCPT ); Tue, 4 Apr 2023 14:04:49 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F6E84219 for ; Tue, 4 Apr 2023 11:04:33 -0700 (PDT) Received: from pps.filterd (m0246632.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 334DwtrG022669; Tue, 4 Apr 2023 18:04:15 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : content-transfer-encoding : content-type : mime-version; s=corp-2022-7-12; bh=vQVFlom304Zmzd+iNcoZIdmjn9O6Eur26Ibd7OK8M/Q=; b=nHamcrV5+h/MwQZ1VCO6D+57CzfEcuVGZvRuL7val7d1ny8mI7KRpXwuEYOCVXnC3rLI JHZ2/MvYBGb6fg4AeTCpT07NcvgVjC53YDgswNQH5/GHGJYDMGiEGjJBOROEyyeXxySU JolPjK9ESjpmd4rJzZdQZ5K57L0FMvmrkDgXfSe/weUaU3rnHKvFR9wsOfDe9Yw0lXak o11EPptzfarC480QMLGyh9nl1vD3Sz7qYxSc+m4gR+rNRSsr+erNTqM/9goY+UGMOT6r 1wkMNpIur5/vH4TUjg/1Sbsphf7dfIhokP35mXvHrCTfJ9tpSTfNgpEmzbEk6UxNQvti 2g== Received: from phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta02.appoci.oracle.com [147.154.114.232]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3ppc7txg02-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 04 Apr 2023 18:04:15 +0000 Received: from pps.filterd (phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 334GpFWU001253; Tue, 4 Apr 2023 18:04:14 GMT Received: from nam11-co1-obe.outbound.protection.outlook.com (mail-co1nam11lp2169.outbound.protection.outlook.com [104.47.56.169]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3ppt3hg1nd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 04 Apr 2023 18:04:14 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=ao7GTM418pnlG8C8R/BkI5ci0li5km1J0HUqPY4O5JpzIC0YQMQedhnLtyNvwC0Pv2DBy+oYVDMW+UQN7E7uNIQ4kskuucbs123+0NTciVbc5udgPfg2A1vVucrI8yEmnoKAfQCK0tzF+ud2XTYgCZ48NutecL873f7CUvoGy4WjOVHgQLuzsYbqLeu86otlysgTKPAq6egt1PflcfypE/3vl7L8LuO/UBv2dkHSWUvDNzntTF0WxJhR3btKHXEQk0DqMgux9Mrf8BGFTKgxmLBLL2U2kRAPxCl7zXghBt4IvSQjkFVDOh4X3hGf10XIcZ5TjatuAoVD5YF35RWJvA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=vQVFlom304Zmzd+iNcoZIdmjn9O6Eur26Ibd7OK8M/Q=; b=bM7Pnl/ND+rfwgMVVMdZeBo7ffYm7dSISKz9GxVmclilAlvfQvWrX+0QcO1lRsz2XJDWFobpedpiayL+CgPkCgnBm9QuLhrOd9AE0aM/NTbF6ZyM+8sCDZDk5WNBq8tOd2Aji4HlVRkS/1IxLJdUxQKFefjtC5wGsKzZvogP47VqQY9/sB87IDe69rBvvYB8kZRSbCJuja32h+HV2dnUPU1yVkxU61hNiHPoNq2aGXATqVd4txyO/365r538nbcqULM9xuvWo+DKq0y5qP0R0/8FKFjFI2ZFkPja/W0Ulr/+ZUjcUYhIPRTjBzCjqwwdbYVDjXiwq5IjhB16NeQxqw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=vQVFlom304Zmzd+iNcoZIdmjn9O6Eur26Ibd7OK8M/Q=; b=c9tXgCvA5MdMXMkQTcniuqU9sCUnYdEJUXOoK/3YiLjpQscqc0fXZuqQkO4P2bPSBQcNpw35xha+VfdR9bBbeyDZ7HOs0OgrDf4Z6xihciJmxTcOBu1kl/3XYX1JPub+9MDT+I+GbHXo1Z6dHHNsrtymAn1hhWcHdgGcfo6cwis= Received: from CO1PR10MB4531.namprd10.prod.outlook.com (2603:10b6:303:6c::22) by MN0PR10MB5909.namprd10.prod.outlook.com (2603:10b6:208:3cf::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6254.33; Tue, 4 Apr 2023 18:04:11 +0000 Received: from CO1PR10MB4531.namprd10.prod.outlook.com ([fe80::e9ed:8782:64cb:cfc3]) by CO1PR10MB4531.namprd10.prod.outlook.com ([fe80::e9ed:8782:64cb:cfc3%9]) with mapi id 15.20.6254.028; Tue, 4 Apr 2023 18:04:11 +0000 From: Eric DeVolder To: linux-kernel@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, ebiederm@xmission.com, dyoung@redhat.com, bhe@redhat.com, vgoyal@redhat.com Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, nramas@linux.microsoft.com, thomas.lendacky@amd.com, robh@kernel.org, efault@gmx.de, rppt@kernel.org, david@redhat.com, sourabhjain@linux.ibm.com, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, eric.devolder@oracle.com Subject: [PATCH v21 6/7] crash: change crash_prepare_elf64_headers() to for_each_possible_cpu() Date: Tue, 4 Apr 2023 14:03:25 -0400 Message-Id: <20230404180326.6890-7-eric.devolder@oracle.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20230404180326.6890-1-eric.devolder@oracle.com> References: <20230404180326.6890-1-eric.devolder@oracle.com> X-ClientProxiedBy: MN2PR07CA0012.namprd07.prod.outlook.com (2603:10b6:208:1a0::22) To CO1PR10MB4531.namprd10.prod.outlook.com (2603:10b6:303:6c::22) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CO1PR10MB4531:EE_|MN0PR10MB5909:EE_ X-MS-Office365-Filtering-Correlation-Id: 0d353f33-25d0-4961-e87d-08db3536fe47 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CO1PR10MB4531.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(376002)(346002)(39860400002)(396003)(136003)(366004)(451199021)(83380400001)(4326008)(8676002)(66946007)(316002)(66556008)(66476007)(86362001)(2906002)(41300700001)(478600001)(36756003)(38100700002)(2616005)(8936002)(6486002)(5660300002)(6512007)(7416002)(186003)(107886003)(6666004)(26005)(6506007)(1076003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 0d353f33-25d0-4961-e87d-08db3536fe47 X-MS-Exchange-CrossTenant-AuthSource: CO1PR10MB4531.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Apr 2023 18:04:11.6432 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 7eOW5BwqhNOpjrA9pL8ZgBCEf9BcsqkPqa1Ly6g0sng/sLD5PbIkJpxVmNOoMaQt366qL3KT0d5L+/qAxH8FGTwvLvhdwHSE4z4BSgeBrRs= X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN0PR10MB5909 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-04-04_09,2023-04-04_05,2023-02-09_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 adultscore=0 phishscore=0 bulkscore=0 mlxscore=0 malwarescore=0 mlxlogscore=999 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2304040165 X-Proofpoint-ORIG-GUID: C2l8KkNHT6fZh_5KIElbtnqsb5UOwgfK X-Proofpoint-GUID: C2l8KkNHT6fZh_5KIElbtnqsb5UOwgfK X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW,RCVD_IN_MSPIKE_H2, SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1762270750820922999?= X-GMAIL-MSGID: =?utf-8?q?1762270750820922999?= The function crash_prepare_elf64_headers() generates the elfcorehdr which describes the CPUs and memory in the system for the crash kernel. In particular, it writes out ELF PT_NOTEs for memory regions and the CPUs in the system. With respect to the CPUs, the current implementation utilizes for_each_present_cpu() which means that as CPUs are added and removed, the elfcorehdr must again be updated to reflect the new set of CPUs. The reasoning behind the change to use for_each_possible_cpu(), is: - At kernel boot time, all percpu crash_notes are allocated for all possible CPUs; that is, crash_notes are not allocated dynamically when CPUs are plugged/unplugged. Thus the crash_notes for each possible CPU are always available. - The crash_prepare_elf64_headers() creates an ELF PT_NOTE per CPU. Changing to for_each_possible_cpu() is valid as the crash_notes pointed to by each CPU PT_NOTE are present and always valid. Furthermore, examining a common crash processing path of: kernel panic -> crash kernel -> makedumpfile -> 'crash' analyzer elfcorehdr /proc/vmcore vmcore reveals how the ELF CPU PT_NOTEs are utilized: - Upon panic, each CPU is sent an IPI and shuts itself down, recording its state in its crash_notes. When all CPUs are shutdown, the crash kernel is launched with a pointer to the elfcorehdr. - The crash kernel via linux/fs/proc/vmcore.c does not examine or use the contents of the PT_NOTEs, it exposes them via /proc/vmcore. - The makedumpfile utility uses /proc/vmcore and reads the CPU PT_NOTEs to craft a nr_cpus variable, which is reported in a header but otherwise generally unused. Makedumpfile creates the vmcore. - The 'crash' dump analyzer does not appear to reference the CPU PT_NOTEs. Instead it looks-up the cpu_[possible|present|onlin]_mask symbols and directly examines those structure contents from vmcore memory. From that information it is able to determine which CPUs are present and online, and locate the corresponding crash_notes. Said differently, it appears that 'crash' analyzer does not rely on the ELF PT_NOTEs for CPUs; rather it obtains the information directly via kernel symbols and the memory within the vmcore. (There maybe other vmcore generating and analysis tools that do use these PT_NOTEs, but 'makedumpfile' and 'crash' seems to be the most common solution.) This change results in the benefit of having all CPUs described in the elfcorehdr, and therefore reducing the need to re-generate the elfcorehdr on CPU changes, at the small expense of an additional 56 bytes per PT_NOTE for not-present-but-possible CPUs. On systems where kexec_file_load() syscall is utilized, all the above is valid. On systems where kexec_load() syscall is utilized, there may be the need for the elfcorehdr to be regenerated once. The reason being that some archs only populate the 'present' CPUs in the /sys/devices/system/cpus entries, which the userspace 'kexec' utility uses to generate the userspace-supplied elfcorehdr. In this situation, one memory or CPU change will rewrite the elfcorehdr via the crash_prepare_elf64_headers() function and now all possible CPUs will be described, just as with kexec_file_load() syscall. Suggested-by: Sourabh Jain Signed-off-by: Eric DeVolder Reviewed-by: Sourabh Jain --- kernel/crash_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 0d87b796e5cf..4aa3c7a6b390 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -364,8 +364,8 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map, ehdr->e_ehsize = sizeof(Elf64_Ehdr); ehdr->e_phentsize = sizeof(Elf64_Phdr); - /* Prepare one phdr of type PT_NOTE for each present CPU */ - for_each_present_cpu(cpu) { + /* Prepare one phdr of type PT_NOTE for each possible CPU */ + for_each_possible_cpu(cpu) { phdr->p_type = PT_NOTE; notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu)); phdr->p_offset = phdr->p_paddr = notes_addr;