Re: Kernel oops with 2.6.26, padlock and ipsec: probably problemwith fpu state changes

[H. Peter Anvin]

Herbert Xu wrote:
> On Fri, Aug 08, 2008 at 04:11:21PM -0700, Suresh Siddha wrote:
> > With out the recent dynamic fpu allocation changes, while we don't see oops,
> > there is a possible race still present in older kernels(for example,
> > while kernel is using kernel_fpu_begin() in some optimized clear/copy
> > page and an interrupt/softirq happens which uses these padlock
> > instructions generating DNA fault).
>
> No this wasn't a problem because kernel_fpu_begin clears TS and
> therefore we don't get faults on SSE instructions.
>
> However, with your patch it will become a problem due to the
> fact that it wasn't designed to be nested.

We're invoking this code from interrupt handlers?

	-hpa

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