From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754764Ab0D0RJi (ORCPT ); Tue, 27 Apr 2010 13:09:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36204 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754119Ab0D0RJh (ORCPT ); Tue, 27 Apr 2010 13:09:37 -0400 Message-ID: <4BD71A2D.6050309@redhat.com> Date: Tue, 27 Apr 2010 13:09:01 -0400 From: Prarit Bhargava User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.5) Gecko/20091210 Fedora/3.0-4.el6 Thunderbird/3.0 MIME-Version: 1.0 To: Konrad Rzeszutek Wilk CC: linux-kernel@vger.kernel.org, suresh.b.siddha@intel.com, x86@kernel.org, clalance@redhat.com, drjones@redhat.com Subject: Re: [LKML] [PATCH] Fix NULL pointer for Xen guests References: <20100427152434.16193.49104.sendpatchset@prarit.bos.redhat.com> <20100427165816.GA24707@phenom.dumpdata.com> In-Reply-To: <20100427165816.GA24707@phenom.dumpdata.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/27/2010 12:58 PM, Konrad Rzeszutek Wilk wrote: > On Tue, Apr 27, 2010 at 11:24:42AM -0400, Prarit Bhargava wrote: > >> Upstream PV guests fail to boot because of a NULL pointer. It is possible that >> xen guests have irq_desc->chip_data = NULL. >> > Can you provide a short example of test scenario? As in what I should do > to reproduce this problem? > Take the latest upstream (well ... to be honest, a bit older than that because of some other bugs) -- take 2.6.33 and try to boot it as a PV guest. I'm using a RHEL5 Xen HV fwiw ... P. >> Test for NULL chip_data pointer before attempting to complete an irq move. >> >> Signed-off-by: Prarit Bhargava >> Acked-by: Suresh Siddha >> >> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c >> index 127b871..eb2789c 100644 >> --- a/arch/x86/kernel/apic/io_apic.c >> +++ b/arch/x86/kernel/apic/io_apic.c >> @@ -2545,6 +2545,9 @@ void irq_force_complete_move(int irq) >> struct irq_desc *desc = irq_to_desc(irq); >> struct irq_cfg *cfg = desc->chip_data; >> >> + if (!cfg) >> + return; >> + >> __irq_complete_move(&desc, cfg->vector); >> } >> #else >> -- >> 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/ >>