Re: [PATCH 4.4 103/105] Revert "x86/mm/pat: Ensure cpa->pfn only contains page frame numbers"

From: Greg Kroah-Hartman
Date: Sat Aug 25 2018 - 11:07:33 EST


On Sat, Aug 25, 2018 at 06:52:32AM -0700, Guenter Roeck wrote:
> Hi Roland,
>
> On 08/24/2018 01:04 PM, Roland Dreier wrote:
> > > Ok, so what patch should be reverted? I'm seeing other reports of
> > > problems all around this same area, but I can't figure out exactly what
> > > to do.
> >
> > Are any of those reports public? If so can you point me at them, I'm
> > curious if the symptoms match up.
> >
> > I don't think we want to revert anything. I think you should pull in
> > edc3b9129cec and at least the first three patches that Ben listed:
> >
> > 21cdb6b56843 x86/mm: Page align the '_end' symbol to avoid pfn conversion bugs
> > b61a76f8850d x86/efi: Map RAM into the identity page table for mixed mode
> > 753b11ef8e92 x86/efi: Setup separate EFI page tables in kexec paths
> >
> > the first patch takes a bit of massaging (mostly because some of it is
> > already touched by 02ff2769edbc, which keeps the changes from
> > edc3b9129cec, and so we can drop a good bit when applying). The other
> > three apply cleanly.
> >
> > I'm currently testing that and can send you the state of my tree in a bit.
> >
>
> Have you made any progress ? On my side I am still out of luck since I can not
> reproduce the problem.

Perhaps just the patch that Andi posted to the stable list helps out
here?

Roland, can you try just that?

thanks,

greg k-h