From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754765AbYIEISW (ORCPT ); Fri, 5 Sep 2008 04:18:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752858AbYIEISJ (ORCPT ); Fri, 5 Sep 2008 04:18:09 -0400 Received: from py-out-1112.google.com ([64.233.166.182]:24054 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752647AbYIEISH (ORCPT ); Fri, 5 Sep 2008 04:18:07 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=Kk3EzlmxZDP28xISiLf0xh7yV/dEfYi+eEWbJw0Gr1RyNzVSC8sup+bg7qVs+P0e5q Ubzmb4JOSbdh5l66tbpCN1Ta9SAr2EYQMJFQOwHkjmkclXSvcRM6Pmxk3rG0e9PhX4BX xfCSpjJ+j2mYUpkBie6rh0WJ9kRSgjaZhSVRY= Message-ID: <19f34abd0809050118g38c87ca5i56fb3cc6d01b7f1a@mail.gmail.com> Date: Fri, 5 Sep 2008 10:18:06 +0200 From: "Vegard Nossum" To: "Takashi Iwai" Subject: Re: PROBLEM: Kernel 2.6.26 oops if I unplug my Logitech USB 1.1 headset Cc: "Andrew Morton" , "Edgar Kalkowski" , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org In-Reply-To: <19f34abd0809050101h2b207d19k9d1bd67351499385@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <48C069B1.3000201@edgar-kalkowski.de> <20080904172822.e5390a59.akpm@linux-foundation.org> <19f34abd0809050058h1e463acdnbfdbfcfa3ef79391@mail.gmail.com> <19f34abd0809050101h2b207d19k9d1bd67351499385@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 5, 2008 at 10:01 AM, Vegard Nossum wrote: > On Fri, Sep 5, 2008 at 9:58 AM, Vegard Nossum wrote: >> On Fri, Sep 5, 2008 at 9:09 AM, Takashi Iwai wrote: >>> At Thu, 4 Sep 2008 17:28:22 -0700, >>> Andrew Morton wrote: >>>> >>>> On Fri, 05 Sep 2008 01:05:21 +0200 >>>> Edgar Kalkowski wrote: >>>> >>>> > Dear kernel hackers. ;) >>>> > >>>> > [1.] One line summary of the problem: If I unplug my USB-Headset the kernel oopses. >>>> >>>> cc's added. >>>> >>>> Might be USB, might be ALSA. >>> >>> Hm, it's hard to guess... >>> Edgar, could you check whether it happens with 2.6.25? >> >> Hi, >> >> I recognize this address: >> >>>>> BUG: unable to handle kernel paging request at 00100100 >> >> Is this a magic value? I also got it, see for example: >> http://lkml.org/lkml/2008/8/21/426 >> >> Google will also recognize it: >> http://www.google.com/search?hl=en&q="unable+to+handle+kernel+paging+request"+00100100 >> >> Where does it come from? > > Oh. It _is_ LIST_POISON1. Sorry for the bit of noise. Probably totally unrelated, but I couldn't help to find this bit of code somewhat odd. In snd_ctl_dev_disconnect(): down_read(&card->controls_rwsem); list_for_each_entry(ctl, &card->ctl_files, list) { wake_up(&ctl->change_sleep); kill_fasync(&ctl->fasync, SIGIO, POLL_ERR); } up_read(&card->controls_rwsem); ...shouldn't that be using &card->ctl_files_rwlock instead of &card->controls_rwsem? That one is always used to protect the list ops on &card->ctl_files in all the other places. Or maybe it is already locked from higher ups? Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036