Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751200AbaDPCFZ (ORCPT ); Tue, 15 Apr 2014 22:05:25 -0400 Received: from mga11.intel.com ([192.55.52.93]:57986 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750982AbaDPCFY (ORCPT ); Tue, 15 Apr 2014 22:05:24 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,868,1389772800"; d="scan'208";a="521367494" Message-ID: <534DE562.8040700@linux.intel.com> Date: Tue, 15 Apr 2014 19:05:22 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Jet Chen CC: LKML , Fengguang Wu Subject: Re: [x86, smap] general protection fault: fff2 [#1] PREEMPT DEBUG_PAGEALLOC References: <53477D33.8030809@intel.com> In-Reply-To: <53477D33.8030809@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/10/2014 10:27 PM, Jet Chen wrote: > [ 371.380921] general protection fault: fff2 [#1] PREEMPT DEBUG_PAGEALLOC I am guessing this is an issue with DEBUG_PAGEALLOC... this message is odd in the extreme because it is hard to see how we could #GP(0xfff2) here -- which normally would indicate having attempted to load 0xfff2 as a segment selector (which is going to fail spectacularly). This happens immediately after a popfq which enables interrupts(!), so my guess is that we're trying to deliver an interrupt but that for some reason there is garbage in the IDT or similar. Unfortunately the GPF message doesn't include the IDT/GDT information... -hpa -- 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/