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Date: Thu, 11 Jan 2018 20:11:30 +0100
From: Willy Tarreau <w@1wt.eu>
To: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
        Alexei Starovoitov <alexei.starovoitov@gmail.com>,
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        Kees Cook <keescook@chromium.org>
Subject: Re: [RFC PATCH v2 6/6] x86/entry/pti: don't switch PGD on when
 pti_disable is set
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On Thu, Jan 11, 2018 at 10:38:07AM -0800, Dave Hansen wrote:
> On 01/11/2018 10:32 AM, Josh Poimboeuf wrote:
> >> hmm. Exposing cr3 to user space will make it trivial for user process
> >> to know whether kpti is active. Not sure how exploitable such
> >> information leak.
> > It's already trivial to detect PTI from user space.
> 
> Do tell.

Probably because meltdown doesn't work anymore ? :-)

Willy