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List:       linux-kernel
Subject:    Re: BUG or virtualbox issue?
From:       Rik van Riel <riel () redhat ! com>
Date:       2008-12-26 19:42:03
Message-ID: 4955338B.2010804 () redhat ! com
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Udo van den Heuvel wrote:
> Hello,
> 
> Just started virtualbox for the first time on x86_64 Phenom system; is 
> this a kernel issue or something for the VirtualBox people?
> 
> Dec 26 12:20:01 surfplank2 kernel: BUG: using smp_processor_id() in 
> preemptible [00000000] code: VirtualBox/26774
> Dec 26 12:20:01 surfplank2 kernel: caller is RTMpCpuId+0x9/0x10 [vboxdrv]
> Dec 26 12:20:01 surfplank2 kernel: Pid: 26774, comm: VirtualBox Not 
> tainted 2.6.28 #3

Looks like the virtualbox code forgot to switch off
preemption before calling smp_processor_id().

This is broken, because the thread could get de-scheduled
and re-scheduled onto another CPU, which means the code
could end up using the wrong smp processor ID.

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