Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755758AbYJEPGu (ORCPT ); Sun, 5 Oct 2008 11:06:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754315AbYJEPGk (ORCPT ); Sun, 5 Oct 2008 11:06:40 -0400 Received: from mga05.intel.com ([192.55.52.89]:54193 "EHLO fmsmga101.fm.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754066AbYJEPGj (ORCPT ); Sun, 5 Oct 2008 11:06:39 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.33,363,1220252400"; d="scan'208";a="623576894" Message-ID: <48E8D7A5.7060508@linux.intel.com> Date: Sun, 05 Oct 2008 08:05:09 -0700 From: Arjan van de Ven User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) MIME-Version: 1.0 To: Thomas Gleixner CC: Jesse Brandeburg , Jiri Kosina , Jesse Barnes , David Miller , jesse.brandeburg@intel.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, kkeil@suse.de, agospoda@redhat.com, david.graham@intel.com, bruce.w.allan@intel.com, john.ronciak@intel.com, chris.jones@canonical.com, tim.gardner@canonical.com, airlied@gmail.com, Olaf Kirch , Linus Torvalds Subject: Re: [RFC PATCH 02/12] On Tue, 23 Sep 2008, David Miller wrote: References: <20080930030825.22950.18891.stgit@jbrandeb-bw.jf.intel.com> <200810021523.45884.jbarnes@virtuousgeek.org> <20081003.134634.240211201.davem@davemloft.net> <200810031429.22598.jbarnes@virtuousgeek.org> <4807377b0810031628x43f79eferdbb9c9c264a5816e@mail.gmail.com> <4807377b0810041824u5ea472d1q4cf5ff606bd23a11@mail.gmail.com> In-Reply-To: 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 Content-Length: 1202 Lines: 26 Thomas Gleixner wrote: > On Sat, 4 Oct 2008, Jesse Brandeburg wrote: >>> Exactly. The access to a ro region results in a fault. I have nowhere >>> seen that trigger, but I can reproduce the trylock() WARN_ON, which >>> confirms that there is concurrent access to the NVRAM registers. The >>> backtrace pattern is similar to the one you have seen. >> are you still getting WARN_ON *with* all the mutex based fixes already applied? > > The WARN_ON triggers with current mainline. Is there any fixlet in > Linus tree missing ? > >> with the mutex patches in place (without protection patch) we are >> still reproducing the issue, until we apply the set_memory_ro patch. > > That does not make sense to me. If the memory_ro patch is providing > _real_ protection then you _must_ run into an access violation. If not, > then the patch just papers over the real problem in some mysterious > way. > not if the bad code is doing copy_to_user .... (or similar) -- 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/