Re: [PATCH 1/3] mm/hugetlb: Fix race condition of uffd missing/minor handling

[Peter Xu]

On Mon, Oct 03, 2022 at 02:00:36PM -0700, Nadav Amit wrote:
> On Oct 3, 2022, at 8:56 AM, Peter Xu <peterx@xxxxxxxxxx> wrote:
> 
> > 
> > +			 */
> > +			if (hugetlb_pte_stable(h, mm, ptep, old_pte))
> > +				ret = hugetlb_handle_userfault(
> > +				    vma, mapping, idx, flags, haddr,
> > +				    address, VM_UFFD_MISSING);
> > +			else
> > +				/* Retry the fault */
> > +				ret = 0;
> 
> Might be unrelated, but at least for the sake of consistency if not
> potential GUP issues, don’t you want to return VM_FAULT_RETRY ?

VM_FAULT_RETRY implies releasing of mmap sem, while we didn't?

-- 
Peter Xu