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

From: Borislav Petkov
Date: Tue Apr 22 2014 - 07:23:24 EST


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@xxxxxxxxx> 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 :-)

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/