From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752986Ab1GTSIK (ORCPT ); Wed, 20 Jul 2011 14:08:10 -0400 Received: from mail-fx0-f52.google.com ([209.85.161.52]:40553 "EHLO mail-fx0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752504Ab1GTSIJ (ORCPT ); Wed, 20 Jul 2011 14:08:09 -0400 Message-ID: <4E271A66.40307@colorfullife.com> Date: Wed, 20 Jul 2011 20:11:50 +0200 From: Manfred Spraul User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.18) Gecko/20110621 Fedora/3.1.11-1.fc15 Thunderbird/3.1.11 MIME-Version: 1.0 To: Eric Dumazet CC: Harald Laabs , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [BUG] null-pointer in task_rq_lock (2.6.35 to 3.0-rc7) References: <4E25E2F5.7090807@dasr.de> <1311110082.3113.27.camel@edumazet-laptop> In-Reply-To: <1311110082.3113.27.camel@edumazet-laptop> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/19/2011 11:14 PM, Eric Dumazet wrote: > Le mardi 19 juillet 2011 à 22:03 +0200, Harald Laabs a écrit :Hi, >> >> I'm not able to fix or understand this bug myself, its already in >> bugzilla with the call trace: >> https://bugzilla.kernel.org/show_bug.cgi?id=27142 >> >> Is there any more useful information I can provide? Anything to test? Could you build a kernel with CONFIG_DEBUG_LIST enabled? Does it report anything? >> Does anyone know of changes from 2.6.34 to 2.6.35 that might have >> broken this? (The diff and the changelog do not enlighten me, too >> much changed and I understand little of it.) > I feel commit 0a2b9d4c79671b059568 might be the bug origin > (ipc/sem.c: move wake_up_process out of the spinlock section) > I'll try to reproduce the bug tomorrow. Perhaps a race with multiple processes sleeping, some/all woken up by a signal an a concurrent IPC_RM. But I don't see the bug yet. -- Manfred