From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754101AbYIFQOo (ORCPT ); Sat, 6 Sep 2008 12:14:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752164AbYIFQOf (ORCPT ); Sat, 6 Sep 2008 12:14:35 -0400 Received: from rv-out-0506.google.com ([209.85.198.232]:37931 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752055AbYIFQOf (ORCPT ); Sat, 6 Sep 2008 12:14:35 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=edJPvWrha6lVLi0FC+IEgmv4pPIA4mXrzOS9Y+X8rnfDNlpB9nUNHM6MLAx8c4q+ST fXz0gtkmej+7wppcGnJUp7px+iXvBuDFGPUkIrl2TDDd7NvDsgx+7+kfJjCfz25uU7d1 +Gqv/tbolxkkUm5aoFH1K8ub68ieDJTLVQALw= Message-ID: <86802c440809060914n31f34adal513273bb6dcbef6a@mail.gmail.com> Date: Sat, 6 Sep 2008 09:14:34 -0700 From: "Yinghai Lu" To: "Ingo Molnar" Subject: Re: [2.6.27] overlapping early reservations [was: early exception - lockdep related?] Cc: "H. Peter Anvin" , "Peter Zijlstra" , "Luca Tettamanti" , linux-kernel@vger.kernel.org, mingo@redhat.com In-Reply-To: <20080906134118.GD4910@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <68676e00809051217h3da02a6bld4412b4a2ee3b728@mail.gmail.com> <1220642738.11202.21.camel@twins.programming.kicks-ass.net> <48C19415.9060108@kernel.org> <20080906134118.GD4910@elte.hu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Sep 6, 2008 at 6:41 AM, Ingo Molnar wrote: > > * H. Peter Anvin wrote: > >> Peter Zijlstra wrote: >>> On Fri, 2008-09-05 at 21:17 +0200, Luca Tettamanti wrote: >>>> On Thu, Sep 4, 2008 at 10:51 PM, Luca Tettamanti wrote: >>>>> On Thu, Sep 4, 2008 at 4:25 PM, Peter Zijlstra wrote: >>>>>> Sadly your config just boots, albeit not to userspace due to missing >>>>>> drivers. >>>>> Yes, I managed to boot it with qemu... I tried kgdb - without luck - >>>>> kernel dies too early. >>>>> I also managed to get a stack trace :D >>>>> >>>>> http://img151.imageshack.us/my.php?image=tracedm1.jpg >>>>> >>>>> It seems that lockdep is an innocent bystander... the kernel died with >>>>> panic() in __reserve_early, and then took another exception while >>>>> printing the panic (I guess). >>>>> Will add further debug stuff to see wtf is going on. >>>> Hum, kernel says: >>>> >>>> http://img177.imageshack.us/my.php?image=overlappingus2.jpg >>>> >>>> Overlapping early reservations b98000-eff266 RAMDISK to 200000-d09cf7 >>>> TEXT DATA BSS >>>> >>>> It would appear that the initramfs is overlapping the kernel itself, >>>> is the boot loader (LILO) doing something stupid? >>> >>> Suppose it is, lets ask hpa.. >>> >> >> It definitely looks like it. > > yeah. Kernel is loaded at the standard 2MB physical, and goes up to > 13.6MB physical. That's a tad large at 11.6 MB but still valid. > > ramdisk image goes from 11.6 MB to 14.9 MB - roughly standard size. That > overlaps 2 MB into the kernel image so we have to panic. LILO should > have loaded the ramdisk somewhere else. (or should have aborted the boot > if it cannot do that) > > We could perhaps print a prominent warning, delay the boot for 5 seconds > or so via mdelay(5000) and simply not load the ramdisk if this happens? > The kernel is obviously still functional - and such a large vmlinuz > likely has all the built-in drivers to boot up to user-space - the lack > of the ramdisk does not necessarily hurt . > wonder if lilo is fixing bzImage from 1M, and when it is calculating pos of ramdisk...base that later on-same-position uncompressing, put vmlinux from 2M... it seems kexec is puting initrd as high as possible, or could specify the ramdisk postion .. wonder if new lilo could help. YH