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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 9562FCA9EA0 for ; Tue, 22 Oct 2019 13:44:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 69F5F20700 for ; Tue, 22 Oct 2019 13:44:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="OuMSKRWw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732103AbfJVNoA (ORCPT ); Tue, 22 Oct 2019 09:44:00 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:24531 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731707AbfJVNoA (ORCPT ); Tue, 22 Oct 2019 09:44:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571751838; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to; bh=zHfL5vClgCqy3xfsuPRygxfVvqfz2goIqbC4zkAjqZY=; b=OuMSKRWwCxsa+Ue4CZQyeI2kAZXy/pnPOwWlGjkSqKOfqk9K5cpl+ugi5niikCXE63iJzQ XTVVYr/22CfJ7p9FSJ3GBwGn/57vJ/MyC3epDzVQED8Sv/4VSz37UO8vjuwwMOiAW0mz0u XpgKZ0OIpdAcRZAbts/7l+umL6LafjI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-198-I13NcTyKPKiRhLkpj3_Img-1; Tue, 22 Oct 2019 09:43:57 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BEF0D5ED for ; Tue, 22 Oct 2019 13:43:54 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B1FD51059A53 for ; Tue, 22 Oct 2019 13:43:54 +0000 (UTC) Received: from zmail24.collab.prod.int.phx2.redhat.com (zmail24.collab.prod.int.phx2.redhat.com [10.5.83.30]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id A7C8218089DC for ; Tue, 22 Oct 2019 13:43:54 +0000 (UTC) Date: Tue, 22 Oct 2019 09:43:54 -0400 (EDT) From: Dave Anderson To: Linux Kernel Mailing List Message-ID: <1789830883.7797936.1571751834645.JavaMail.zimbra@redhat.com> In-Reply-To: <55902207.7797907.1571751831873.JavaMail.zimbra@redhat.com> Subject: Re: [PATCH 1/3 v4] x86/kdump: always reserve the low 1MiB when the crashkernel option is specified MIME-Version: 1.0 X-Originating-IP: [10.18.17.5, 10.4.195.9] Thread-Topic: x86/kdump: always reserve the low 1MiB when the crashkernel option is specified Thread-Index: 85xNxgPNoOZRUFlcGwROOLaIM4U0zw== X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-MC-Unique: I13NcTyKPKiRhLkpj3_Img-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ---- Original Message ----- > >=20 > > [root linux]$ crash vmlinux > > /var/crash/127.0.0.1-2019-09-19-08\:31\:27/vmcore > > WARNING: kernel relocated [240MB]: patching 97110 gdb minimal_symbol va= lues > >=20 > > KERNEL: /var/crash/127.0.0.1-2019-09-19-08:31:27/vmlinux > > DUMPFILE: /var/crash/127.0.0.1-2019-09-19-08:31:27/vmcore [PARTIAL= DUMP] > > CPUS: 128 > > DATE: Thu Sep 19 08:31:18 2019 > > UPTIME: 00:01:21 > > LOAD AVERAGE: 0.16, 0.07, 0.02 > > TASKS: 1343 > > NODENAME: amd-ethanol > > RELEASE: 5.3.0-rc7+ > > VERSION: #4 SMP Thu Sep 19 08:14:00 EDT 2019 > > MACHINE: x86_64 (2195 Mhz) > > MEMORY: 127.9 GB > > PANIC: "Kernel panic - not syncing: sysrq triggered crash" > > PID: 9789 > > COMMAND: "bash" > > TASK: "ffff89711894ae80 [THREAD_INFO: ffff89711894ae80]" > > CPU: 83 > > STATE: TASK_RUNNING (PANIC) > >=20 > > crash> kmem -s|grep -i invalid > > kmem: dma-kmalloc-512: slab:ffffd77680001c00 invalid freepointer:a6086a= c099f0c5a4 > > kmem: dma-kmalloc-512: slab:ffffd77680001c00 invalid freepointer:a6086a= c099f0c5a4 > > crash> >=20 > I fail to see what that's trying to tell me? You have invalid pointers? Correct, because the pointer values are encrypted. The command is walking = through the singly-linked list of free objects in a slab from the dma-kmalloc-512 slab = cache. The slab memory had been allocated from low memory, and because of the problem= at hand, it was was copied to the vmcore in its encrypted state. Dave=20