Re: BUG or virtualbox issue?

From: Rik van Riel
Date: Fri Dec 26 2008 - 14:42:19 EST


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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