Re: [PATCH] x86-64: espfix for 64-bit mode *PROTOTYPE*

Borislav Petkov
2014-04-22T11:23:20Z

On Mon, Apr 21, 2014 at 06:53:36PM -0700, Andrew Lutomirski wrote:
> On Mon, Apr 21, 2014 at 6:47 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> > Race condition (although with x86 being globally ordered, it probably can't actually happen.) The bitmask is probably the way to go.
>
> Does the race matter? In the worst case you take the lock
> unnecessarily. But yes, the bitmask is easy.

I wonder if it would be workable to use a bit in the espfix PGD to
denote that it has been initialized already... I hear, near NX there's
some room :-)

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Regards/Gruss,
Boris.

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