Re: v2.6.27-rc7: x86: #GP on panic?

From: H. Peter Anvin
Date: Thu Sep 25 2008 - 17:54:18 EST


Vegard Nossum wrote:
On Thu, Sep 25, 2008 at 10:49 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
Seems like an external interrupt happened and was delivered after the sti?

Hm. I guess it smells like a qemu bug since it's rather easily
reproducible here and sounds strange that nobody else saw it. Is qemu
0.9.1.

Yes, but there shouldn't be any external interrupts that could turn into a
divide error. It really smells like a Qemu problem -- possibly even a Qemu
miscompile -- to me.

Does it reproduce in KVM?

I have no computer that can do KVM, sorry :-(

Stack trace contains IO_APIC functions, so it seems that maybe the
emulated IOAPIC is trying to (erroneously) deliver an int 0 (for some
reason)? But I don't know, that's just speculation which can be done
better by others, so I will stop now :-)


I suspect it's a problem in Qemu's IOAPIC model, but it's hard to know for sure.

-hpa
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