Re: [kernel-hardening] Re: [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode
From: Daniel Gruss
Date: Sun May 07 2017 - 18:19:50 EST
On 2017-05-08 00:02, Richard Weinberger wrote:
Ahh, *very* recent is the keyword then. ;)
I was a bit confused since in your paper the overhead is less than 1%.
Yes, only for very recent platforms (Skylake). While working on the
paper we were surprised that we found overheads that small.
What platforms did you test?
We tested it on multiple platforms for stability, but we only ran longer
performance tests on different Skylake i7-6700K systems we mentioned in
i.e. how does it perform on recent AMD systems?
Unfortunately, we don't have any AMD systems at hand. I'm also not sure
how AMD is affected by the issue in the first place. Although unlikely,
there is the possibility that the problem of KASLR information leakage
through microarchitectural side channels might be Intel-specific.