Re: [REGRESSION][v4.9.y][v4.10.y] x86/efi: Only map RAM into EFI page tables if in mixed-mode

[Ard Biesheuvel]

On 2 February 2017 at 20:17, Joseph Salisbury
<joseph.salisbury@xxxxxxxxxxxxx> wrote:
> Hi Matt,
>
> A kernel bug report was opened against Ubuntu [0].  After a kernel
> bisect, it was found that reverting the following commit resolved this bug:
>
> commit 1297667083d5442aafe3e337b9413bf02b114edb
> Author: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
> Date:   Mon Sep 19 13:09:09 2016 +0100
>
>     x86/efi: Only map RAM into EFI page tables if in mixed-mode
>
>
> The regression was introduced as of v4.8-rc8.  It also still affects
> current mainline.
>
> I was hoping to get your feedback, since you are the patch author.  Do
> you think gathering any additional data will help diagnose this issue,
> or would it be best to submit a revert request?
>

Does this patch help at all?

https://git.kernel.org/cgit/linux/kernel/git/efi/efi.git/commit/?h=urgent&id=090abfc9dc7faf3f84799f956158c8c3af149a81