Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752034AbaBLOFW (ORCPT ); Wed, 12 Feb 2014 09:05:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33928 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751480AbaBLOFT (ORCPT ); Wed, 12 Feb 2014 09:05:19 -0500 Date: Wed, 12 Feb 2014 09:05:16 -0500 From: Vivek Goyal To: Dave Young Cc: keescook@chromium.org, hpa@zytor.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] disable kaslr in kdump kernel Message-ID: <20140212140516.GA16470@redhat.com> References: <20140211100837.GA17202@dhcp-16-126.nay.redhat.com> <20140211131640.GB1055@redhat.com> <20140212013734.GE3709@dhcp-16-126.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140212013734.GE3709@dhcp-16-126.nay.redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 12, 2014 at 09:37:34AM +0800, Dave Young wrote: > On 02/11/14 at 08:16am, Vivek Goyal wrote: > > On Tue, Feb 11, 2014 at 06:08:38PM +0800, Dave Young wrote: > > > > > > KASLR does not work in kdump kernel because it's too early that mem=exactmap > > > has not been parsed. > > > > > > Since KASLR does not make much sense for kdump kernel thus let's disable it > > > for kdump kernel. To check if it is a kdump kernel I just check the cmdline > > > param elfcorehdr just like is_kdump_kernel. > > > > > > Signed-off-by: Dave Young > > > > I don't think it is a good idea. I don't like hardcoding second kernel's > > behavior. I rather vary second kernel's behavior based on command line > > parameters or based on values passed in bootparams. > > > > So I am more than happy to pass command line option "nokaslr" instead > > of hardcoding this in kernel. > > That's also fine to me, but I think we'd better add it to documentation? Adding documentation is fine. May be Documentation/kdump/kdump.txt. Create a section where we mention some of the preferred command line settings for kdump to work. Thanks Vivek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/