Re: [kernel-hardening] Re: [RFC, PATCH] x86_64: KAISER - do not mapkernel in user mode

From: Richard Weinberger
Date: Tue May 09 2017 - 10:57:35 EST


Am 09.05.2017 um 16:44 schrieb Fogh, Anders:
>>> i.e. how does it perform on recent AMD systems?
>
> Sorry for the latency. Recent AMD is reported by Enrique Nissem to not
> be vulnerable to the prefetch attack. TSX attack doesn't apply to AMD.
> Hund, Willems & Holz wrote in 2013 that AMD was vulnerable to that
> attack. The BTB is almost surely working in a different manner of
> fashion if at all. So AMD may or may not be vulnerable to the DPF
> attack, but none of the modern attacks should work - at least out of the
> box.

But the promoted patch will also run on AMD systems, that's why I asked
for the overhead.

Thanks,
//richard