From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753251AbcHWRP1 (ORCPT ); Tue, 23 Aug 2016 13:15:27 -0400 Received: from mga03.intel.com ([134.134.136.65]:27081 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751640AbcHWRPZ (ORCPT ); Tue, 23 Aug 2016 13:15:25 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,567,1464678000"; d="scan'208";a="159910310" From: Alexander Shishkin To: Vince Weaver Cc: Peter Zijlstra , Ingo Molnar , linux-kernel@vger.kernel.org, eranian@google.com, Arnaldo Carvalho de Melo Subject: Re: [PATCH 0/3] perf, bts: Fallout from the fuzzer for perf/urgent In-Reply-To: References: <1471942474-1854-1-git-send-email-alexander.shishkin@linux.intel.com> User-Agent: Notmuch/0.21 (http://notmuchmail.org) Emacs/24.5.1 (x86_64-pc-linux-gnu) Date: Tue, 23 Aug 2016 20:10:34 +0300 Message-ID: <87shtvl8c5.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vince Weaver writes: > On Tue, 23 Aug 2016, Alexander Shishkin wrote: > >> Recently Vince has reported warnings and panics coming from the >> general direction of AUX tracing. I found two bugs which manifest >> similarly, one in intel_bts driver and one in AUX unmapping path. >> >> Both are triggered by racing SET_OUTPUT against mmap_close while >> running AUX tracing. I have a test case that set fire to the kernel >> within a few seconds by doing this, which I can share if anyone >> cares. > > I've applied these and am fuzzing on my Haswell machine and I'm getting > lots and lots of > > [ 945.536374] Dazed and confused, but trying to continue > [ 945.542391] Uhhuh. NMI received for unknown reason 21 on CPU 2. > [ 945.549360] Do you have a strange power saving mode enabled? > [ 945.556701] Dazed and confused, but trying to continue > [ 945.563643] Uhhuh. NMI received for unknown reason 31 on CPU 2. > [ 945.571379] Do you have a strange power saving mode enabled? > [ 945.578754] Dazed and confused, but trying to continue > [ 945.630889] Uhhuh. NMI received for unknown reason 31 on CPU 2. > [ 945.638141] Do you have a strange power saving mode enabled? > [ 945.645523] Dazed and confused, but trying to continue > > messages that I wasn't getting before. Of course, I updated from -rc2 to > -rc3 before applying the patch so it could also be related to that too, I > can try backing out the patches and see if it still happens. Uhhuh, that's not cool, let me look some more. But it should stop dying on bts/aux stuff at least. Regards, -- Alex