From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756104AbZHYTao (ORCPT ); Tue, 25 Aug 2009 15:30:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756095AbZHYTao (ORCPT ); Tue, 25 Aug 2009 15:30:44 -0400 Received: from claw.goop.org ([74.207.240.146]:59213 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756065AbZHYTan (ORCPT ); Tue, 25 Aug 2009 15:30:43 -0400 Message-ID: <4A943BE0.7070308@goop.org> Date: Tue, 25 Aug 2009 12:30:40 -0700 From: Jeremy Fitzhardinge User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Lightning/1.0pre Thunderbird/3.0b3 MIME-Version: 1.0 To: Arnd Hannemann CC: Ingo Molnar , Arnd Hannemann , Pekka Enberg , LKML , "hannes@cmpxchg.org" , "torvalds@linux-foundation.org" , "xen-devel@lists.xensource.com" , Benjamin Herrenschmidt Subject: Re: [bisected] 2.6.31 regression: fails to boot as xen guest References: <4A9407B1.6020400@nets.rwth-aachen.de> <84144f020908250929t7d4a74f1n4827de04e5c4c56a@mail.gmail.com> <4A94161A.2020609@nets.rwth-aachen.de> <1251219129.4852.1.camel@penberg-laptop> <4A94242E.30309@nets.rwth-aachen.de> <1251223399.13451.5.camel@penberg-laptop> <4A942BDD.70303@nets.rwth-aachen.de> <20090825182510.GA6903@elte.hu> <4A942DB9.3020209@goop.org> <4A942F96.7000900@nets.rwth-aachen.de> In-Reply-To: <4A942F96.7000900@nets.rwth-aachen.de> X-Enigmail-Version: 0.97a Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/25/09 11:38, Arnd Hannemann wrote: > Jeremy Fitzhardinge wrote: > >> On 08/25/09 11:25, Ingo Molnar wrote: >> >>> * Arnd Hannemann wrote: >>> >>> >>> >>>> Pekka Enberg wrote: >>>> >>>> >>>>> On Tue, 2009-08-25 at 19:49 +0200, Arnd Hannemann wrote: >>>>> >>>>> >>>>>> Hi Pekka, >>>>>> >>>>>> Pekka Enberg wrote: >>>>>> >>>>>> >>>>>>> On Tue, 2009-08-25 at 18:49 +0200, Arnd Hannemann wrote: >>>>>>> >>>>>>> >>>>>>>>> Thanks for doing the bisect! Can we also see your >>>>>>>>> .config also? >>>>>>>>> >>>>>>>>> >>>>>>>> Config for -rc7 is attached. My bisect configs were based >>>>>>>> on that >>>>>>>> >>>>>>>> >>>>>>> Thanks! While we wait for the Xen people, you can try the >>>>>>> following patch to see if we can narrow the bug down to >>>>>>> trap_init(). >>>>>>> >>>>>>> >>>>>> Yes seems to be trap_init(). -rc7 with this patch applied >>>>>> boots up to the prompt. >>>>>> >>>>>> >>>>> Thanks for testing! Ingo, what do you think of the following >>>>> patch? AFAICT, x86-32 is the only architecture playing with >>>>> traps in mem_init() so this should be the safest fix for >>>>> 2.6.31. >>>>> >>>>> >>>> Hmm, -rc7 + this fix does not work for me :-/ Still hangs before >>>> any output... >>>> >>>> >>> does earlyprintk=vga tell you anything about precisely where it >>> hangs? >>> >>> >> It's a Xen domain, so it should be earlyprintk=xen >> >> J >> >> > Here is the output with earlyprintk=xen and the second patch from pekka > applied: > > (early) [ 0.000000] Initializing CPU#0 > (early) [ 0.000000] Checking if this processor honours the WP bit > even in supervisor mode...(early) > (early) [ 0.000000] BUG: unable to handle kernel (early) NULL pointer > dereference(early) at (null) > (early) [ 0.000000] IP:(early) [] > xen_evtchn_do_upcall+0xd3/0x160 > OK, that's the same problem I've seen; its trying to enable and delver interrupts before init_IRQ has been called, so the various allocated arrays aren't set up. Ingo, I'm assuming that interrupts aren't supposed to be enabled this early? Thanks, J > (early) [ 0.000000] *pdpt = 0000000008386001 (early) > (early) [ 0.000000] Thread overran stack, or stack corrupted > (early) [ 0.000000] Oops: 0000 [#1] (early) SMP (early) > (early) [ 0.000000] last sysfs file: > (early) [ 0.000000] Modules linked in:(early) > (early) [ 0.000000] > (early) [ 0.000000] Pid: 0, comm: swapper Not tainted > (2.6.31-rc7-pae-um #10) > (early) [ 0.000000] EIP: 0061:[] EFLAGS: 00010046 CPU: 0 > (early) [ 0.000000] EIP is at xen_evtchn_do_upcall+0xd3/0x160 > (early) [ 0.000000] EAX: 00000004 EBX: 00000000 ECX: 00000004 EDX: > ffffffff > (early) [ 0.000000] ESI: fffffffe EDI: 00000000 EBP: 00000000 ESP: > c1413e64 > (early) [ 0.000000] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: e021 > (early) [ 0.000000] Process swapper (pid: 0, ti=c1412000 > task=c13d11a0 task.ti=c1412000) > (early) [ 0.000000] Stack: > (early) [ 0.000000] f5793000(early) c146d9f0(early) > c146d9f0(early) 00000000(early) c1413e9c(early) 00000000(early) > 00000000(early) c3a01020(early) > (early) [ 0.000000] <0>(early) 00000000(early) eec06067(early) > c000cff8(early) 00000000(early) 00000000(early) c10086d7(early) > eec06067(early) c000cff8(early) > (early) [ 0.000000] <0>(early) f55ff000(early) c000cff8(early) > 00000000(early) 00000000(early) c13d7d60(early) c101e021(early) > c141e021(early) c10100d8(early) > (early) [ 0.000000] Call Trace: > (early) [ 0.000000] [] ? xen_do_upcall+0x7/0xc > (early) [ 0.000000] [] ? ptep_set_access_flags+0x1/0x80 > (early) [ 0.000000] [] ? find_e820_area_size+0x51/0x330 > (early) > > > Best regards, > Arnd > >