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

[Guenter Roeck]

On 08/25/2018 08:07 AM, Greg Kroah-Hartman wrote:
> 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?

For reference:

https://www.spinics.net/lists/stable/msg253357.html

That would be the most straightforward and simple fix, so I would prefer
to go with it if it works.

Guenter