From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Steven J. Magnani" Subject: Re: Generic DMA - BUG_ON Date: Thu, 21 Jan 2010 09:51:37 -0600 Message-ID: <1264089097.18869.0.camel@iscandar.digidescorp.com> References: <1263982111-24123-1-git-send-email-monstr@monstr.eu> <20100120105350.GA23394@flint.arm.linux.org.uk> <20100120110031.GD8665@amd.com> Reply-To: steve@digidescorp.com Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from mail.digidescorp.com ([66.244.163.200]:54482 "EHLO digidescorp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752077Ab0AUQA7 (ORCPT ); Thu, 21 Jan 2010 11:00:59 -0500 In-Reply-To: <20100120110031.GD8665@amd.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Joerg Roedel Cc: monstr@monstr.eu, linux-kernel@vger.kernel.org, michal.simek@petalogix.com, arnd@arndb.de, linux-arch@vger.kernel.org, fujita.tomonori@lab.ntt.co.jp, akpm@linux-foundation.org, mingo@elte.hu On Wed, 2010-01-20 at 12:00 +0100, Joerg Roedel wrote: > On Wed, Jan 20, 2010 at 10:53:50AM +0000, Russell King wrote: > > and ops is NULL, then this code will oops; you will get a full register > > dump and backtrace. You can use this information along with markup_oops.pl > > to find out where the problem is. > > You can't rely on the oops if the code runs in process context. The > process may have address 0 mapped which would result in a security hole. > We had two of these bugs last year. You also can't rely on an oops in a NOMMU environment. ------------------------------------------------------------------------ Steven J. Magnani "I claim this network for MARS! www.digidescorp.com Earthling, return my space modulator!" #include