Re: + mm-hugetlb-fix-a-addressing-exception-caused-by-huge_pte_offset.patch added to -mm tree

On 3/31/20 7:08 AM, Jason Gunthorpe wrote:

I can't think of an easy fix here.

Andrew, I think this patch has to be dropped :(

Longpeng can fix the direct bug he saw by not changing the pXX_offset(), but this extra de-reference will remain some theortical/rare bug according to the memory model.

FWIW, I tested Longpeng's V2 patch without the READ_ONCE for *pgd and *p4d in this environment and it worked fine.