Re: [RFC PATCH v2 6/6] x86/entry/pti: don't switch PGD on when pti_disable is set

[Olivier Galibert]

Wouldn't the time taken by an easy syscall like getuid be a clear indicator?

  OG.


On Thu, Jan 11, 2018 at 8:17 PM, Dave Hansen
<dave.hansen@xxxxxxxxxxxxxxx> wrote:
> On 01/11/2018 11:07 AM, Borislav Petkov wrote:
>> On Thu, Jan 11, 2018 at 10:57:51AM -0800, Dave Hansen wrote:
>>> I'd love to have a tool that tells you for sure "KPTI enabled or not",
>>> but I'd also love to have it be something I can easily distribute
>>> without it being handled like a WMD.
>> You mean this:
>>
>> https://git.kernel.org/tip/87590ce6e373d1a5401f6539f0c59ef92dd924a9
>
> I meant that works across all the kpti implementations.  Those with gunk
> in /sys, /proc/cpuinfo, or with nothing at all like the original KAISER
> patches I posted.
>
> And, yes, I want a pony.  I just though someone had such a pony handy
> and it was trivial.