Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755066Ab2EVQxD (ORCPT ); Tue, 22 May 2012 12:53:03 -0400 Received: from plane.gmane.org ([80.91.229.3]:50633 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753790Ab2EVQxA (ORCPT ); Tue, 22 May 2012 12:53:00 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: =?ISO-8859-1?Q?J=F6rg-Volker_Peetz?= Subject: Re: Linux 3.4 released Date: Tue, 22 May 2012 18:52:49 +0200 Message-ID: <4FBBC461.4060008@web.de> References: <4FBBB11D.7020904@web.de> <20120522155345.GC14339@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@dough.gmane.org Cc: linux-kernel@vger.kernel.org X-Gmane-NNTP-Posting-Host: p5b371840.dip.t-dialin.net User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.4) Gecko/20120510 Icedove/10.0.4 In-Reply-To: <20120522155345.GC14339@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3239 Lines: 84 Tejun Heo wrote, on 05/22/12 17:53: > Hello, > > On Tue, May 22, 2012 at 05:30:37PM +0200, J?rg-Volker Peetz wrote: >> Switching from self-compiled kernel 3.2 17 to a self compiled kernel 3.4.0, >> a notebook HP Pavilion dv7 gets hard locked with a kernel panic, when trying to >> start a web-cam video viewer (guvcview) for the built-in USB web-cam. >> >> Please find attached a (hand-typed) screen-shot of the text-console and the >> kernel config. >> >> By the way, thank you for all the great work on Linux. >> -- >> Best regards, >> J?rg-Volker. > >> BUG: Unable to handle kernel NULL pointer dereference at 0000000000000008 > ... >> Code: 8b 7c 24 50 48 83 c4 58 c3 66 66 66 2e 0f 1f 84 00 00 00 00 00 48 8b 0f 31 c0 48 89 fa 48 89 ce 40 80 e6 00 83 e1 04 48 0f 45 c6 <48> 8b 70 08 65 8b 3c 25 60 cc 00 00 e9 b9 fc ff ff 66 0f 1f 84 >> RIP [] delayed_work_timer_fn+0x16/0x30 > > So, that looks like get_work_cwq() returning NULL and then > delayed_work_timer_fn() trying to dereference it. Either work item is > being corrupted (e.g. freed early) or somebody is mucking with the > work item embedded in a delayed work item. > > Something like the following may reveal the offending work function. > > Thanks. > > diff --git a/kernel/workqueue.c b/kernel/workqueue.c > index 5abf42f..adc1057 100644 > --- a/kernel/workqueue.c > +++ b/kernel/workqueue.c > @@ -1101,6 +1101,10 @@ static void delayed_work_timer_fn(unsigned long __data) > struct delayed_work *dwork = (struct delayed_work *)__data; > struct cpu_workqueue_struct *cwq = get_work_cwq(&dwork->work); > > + if (!cwq) > + printk("XXX delayed_work_timer_fn: NULL cwq, fn=%pf\n", > + dwork->work.func); > + > __queue_work(smp_processor_id(), cwq->wq, &dwork->work); > } > Hello, I tried the above patch but was not able to see a line beginning with "XXX", not on the text-console nor in any log-file. After the hard-lock, I can see only the console-screen which now changed slightly: BUG: Unable to handle kernel NULL pointer dereference at 0000000000000008 IP: [] delayed_work_timer_fn+0x30/0x60 PGD 214fbc067 PUD 211c50067 PMD 0 Oops: 0000 [#1] SMP CPU 1 ... Call Trace: [] ? __queu_work+0x320/0x320 [] ? run_timer_softirq+0x106/0x220 [] ? tick_handle_oneshot_broadcast+0xb5/0xe0 [] ? __do_softirq+0x8d/0x110 [] ? handle_irq_event_percpu+0x79/0x140 [] ? call_softirq+0x1c/0x26 [] ? do_softirq+0x4d/0x80 [] ? irq_exit+0xa5/0xb0 [] ? do_IRQ+0x5b/0xd0 [] ? common_interrupt+0x67/0x67 [] ? default_idle+0x20/0x40 [] ? amd_e400_idle+0xa8/0xf0 [] ? cpu_idle+0xb6/0xd0 ... After that I have to press the power button until the computer switches off. What else could I do? -- Best regards, J?rg-Volker. -- 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/