From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753635AbZBCVdS (ORCPT ); Tue, 3 Feb 2009 16:33:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751500AbZBCVdD (ORCPT ); Tue, 3 Feb 2009 16:33:03 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:51996 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751501AbZBCVdB (ORCPT ); Tue, 3 Feb 2009 16:33:01 -0500 Date: Tue, 3 Feb 2009 22:32:45 +0100 From: Ingo Molnar To: Luca Olivetti Cc: Daniel Walker , Greg KH , Mauro Carvalho Chehab , linux-kernel@vger.kernel.org, Hans Verkuil , Janne Grunau Subject: Re: [crash] af9005_usb_module_init(): BUG: unable to handle kernel paging request at ff100000 Message-ID: <20090203213245.GD20527@elte.hu> References: <20090203172836.GA6964@elte.hu> <1233685361.5903.131.camel@desktop> <20090203193029.GA13726@elte.hu> <4988ABEE.6020703@ventoso.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4988ABEE.6020703@ventoso.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Luca Olivetti wrote: > En/na Ingo Molnar ha escrit: >> * Daniel Walker wrote: >> >>> On Tue, 2009-02-03 at 18:28 +0100, Ingo Molnar wrote: >>>> FYI, -tip qa keeps triggering this bootup crash occasionally, ever >>>> since June 2008 when a DVB merge brought in this new driver: >>> It looks like it could be a config problem.. The crash happens around >>> these two symbol "af9005_rc_keys", and "af9005_rc_keys_size" , and >>> they are both defined inside af9005-remote.c different from where the >>> init functions is lcoated .. af9005-remote.c needs a special config >>> CONFIG_DVB_USB_AF9005_REMOTE to get compiled which you have >>> disabled.. >> >> ok - but it shouldnt crash, obviously. > > Did you try my suggestion I sent the past December 26th? > Quote: > > El Fri, 26 Dec 2008 11:08:33 -0200 > Mauro Carvalho Chehab escribió: > > > Luca, > > > > > > Could you please verify this issue? > > No, I don't have 2.6.28, but I guess that maybe once usb_register is > called the dvb-usb subsystem asynchronously (is that an smp system?) > starts polling the remote before the rc_decode function pointer has been > initialized. Correct, and the bug triggered on a 'very SMP' system: a hyperthreading system that triggers SMP races much sooner than other (multi-core) SMP systems. It also triggered spuriously - i.e. not in a reproducible way. > Could you try to initialize it to NULL before calling usb_register? Sorry - there was no patch i think for me to try so i didnt try it. I'll try the patch in your next mail. Please queue your fix up for upstream and consider the bug fixed, unless i re-report it in a few days. Since it's a spurious crash there's no clear reproducer i can test. Ingo