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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 B0BEFC43387 for ; Mon, 14 Jan 2019 20:26:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7EBE02064C for ; Mon, 14 Jan 2019 20:26:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727015AbfANU0d (ORCPT ); Mon, 14 Jan 2019 15:26:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39250 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726767AbfANU0d (ORCPT ); Mon, 14 Jan 2019 15:26:33 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0299599CE9; Mon, 14 Jan 2019 20:26:33 +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 E05C75C1B4; Mon, 14 Jan 2019 20:26:32 +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 BBFCE1800540; Mon, 14 Jan 2019 20:26:32 +0000 (UTC) Date: Mon, 14 Jan 2019 15:26:32 -0500 (EST) From: Dave Anderson To: Borislav Petkov Cc: Kazuhito Hagio , Lianbo Jiang , linux-kernel@vger.kernel.org, kexec@lists.infradead.org, tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, akpm@linux-foundation.org, bhe@redhat.com, dyoung@redhat.com, linux-doc@vger.kernel.org Message-ID: <221183717.69773903.1547497592624.JavaMail.zimbra@redhat.com> In-Reply-To: <20190114201812.GT2773@zn.tnic> References: <20190110121944.6050-1-lijiang@redhat.com> <20190114180142.GO2773@zn.tnic> <2126185079.69727846.1547492312033.JavaMail.zimbra@redhat.com> <20190114192144.GQ2773@zn.tnic> <134663991.69764038.1547494607008.JavaMail.zimbra@redhat.com> <20190114195940.GS2773@zn.tnic> <244986363.69770015.1547496453312.JavaMail.zimbra@redhat.com> <20190114201812.GT2773@zn.tnic> Subject: Re: [PATCH 1/2 v6] kdump: add the vmcoreinfo documentation MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.18.17.201, 10.4.195.15] Thread-Topic: kdump: add the vmcoreinfo documentation Thread-Index: XfbVibwlwdOZbF9bts4NjDtwe/BoTQ== X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 14 Jan 2019 20:26:33 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ----- Original Message ----- > On Mon, Jan 14, 2019 at 03:07:33PM -0500, Dave Anderson wrote: > > That's what it *does* utilize -- it takes a standalone vmcore dumpfile, and > > pulls out the OSRELEASE string from it, so that a user can determine what > > vmlinux file should be used with that vmcore for normal crash analysis. > > And the vmcoreinfo is part of the vmcore, right? Correct. > > So it can just as well read out the address of init_uts_ns and get the > kernel version from there. No. It needs *both* the vmlinux file and the vmcore file in order to read kernel virtual memory, so just having a kernel virtual address is insufficient. So it's a chicken-and-egg situation. This particular --osrelease option is used to determine *what* vmlinux file would be required for an actual crash analysis session. Dave