Re: [PATCH v1] x86/power/64: Restore processor state before using per-cpu variables

From: Borislav Petkov
Date: Fri Aug 12 2016 - 01:50:20 EST


On Thu, Aug 11, 2016 at 02:49:29PM -0700, Thomas Garnier wrote:
> Restore the processor state before calling any other function to ensure
> per-cpu variables can be used with KASLR memory randomization.
>
> Tracing functions use per-cpu variables (gs based) and one was called
> just before restoring the processor state fully. It resulted in a double
> fault when both the tracing & the exception handler functions tried to
> use a per-cpu variable.
>
> Signed-off-by: Thomas Garnier <thgarnie@xxxxxxxxxx>
> ---
> Based on next-20160808

Ok, I believe before I test this, I need to apply another patch from
Rafael. I think it is the "Always create temporary identity mapping
correctly" thing.

Yes, no?

Rafael, can you please apply everything on a test branch for us to run?

Thanks.

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