From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gj8ob-0005eA-IR for kexec@lists.infradead.org; Mon, 14 Jan 2019 20:26:34 +0000 Date: Mon, 14 Jan 2019 15:26:32 -0500 (EST) From: Dave Anderson 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 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Borislav Petkov Cc: Kazuhito Hagio , Lianbo Jiang , bhe@redhat.com, linux-doc@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, dyoung@redhat.com, akpm@linux-foundation.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 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec