Re: [PATCH RESEND 0/3] Add restrictions for kexec/kdump jumping between 5-level and 4-level kernel

From: Kirill A. Shutemov
Date: Fri Jan 25 2019 - 07:05:37 EST


On Fri, Jan 25, 2019 at 10:28:14AM +0800, Baoquan He wrote:
> This is a RESEND post.
>
> The original v1 post can be found here:
> http://lkml.kernel.org/r/20180829141624.13985-1-bhe@xxxxxxxxxx
>
> It's trying to fix several corner case issues for kexec/kdump when
> dynamic switching of paging mode is enabled in x86_64. Please click
> above link to check the details.
>
> In v1, hpa raised concern that why the paging mode checking is not done
> before kexec jumping, the discussion can be found here:
>
> http://lkml.kernel.org/r/alpine.DEB.2.21.1809051002020.1416@xxxxxxxxxxxxxxxxxxxxxxx
>
> As tglx said, it might be not doable for kdump since kdump kernel's
> reserved crashkernel region only owns a portion of memory, may
> be above 4G; and might be not safer to do paging mode checking and
> switching thing after crash.
>
> So resend this patchset.

Changes look good to me:

Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

--
Kirill A. Shutemov