diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 27e8136b1815..da5d04edf7c1 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4973,10 +4973,11 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 		raw_write_seqcount_begin(&src->write_protect_seq);
 	} else {
 		/*
-		 * For shared mappings the vma lock must be held before
-		 * calling hugetlb_walk() in the src vma. Otherwise, the
-		 * returned ptep could go away if part of a shared pmd and
-		 * another thread calls huge_pmd_unshare.
+		 * Shared mappings only need copying when we could have
+		 * information stored in page tables (e.g., userfaultfd PTE
+		 * bits or markers), which is incompatible with PMD sharing.
+		 * Still take the hugetlb VMA lock for now to satisfy
+		 * hugetlb_walk()'s locking requirements.
 		 */
 		hugetlb_vma_lock_read(src_vma);
 	}
@@ -4984,6 +4985,13 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 	last_addr_mask = hugetlb_mask_last_page(h);
 	for (addr = src_vma->vm_start; addr < src_vma->vm_end; addr += sz) {
 		spinlock_t *src_ptl, *dst_ptl;
+
+		if (WARN_ON_ONCE(want_pmd_share(src_vma, addr) ||
+				 want_pmd_share(dst_vma, addr))) {
+			ret = -EINVAL;
+			break;
+		}
+
 		src_pte = hugetlb_walk(src_vma, addr, sz);
 		if (!src_pte) {
 			addr |= last_addr_mask;
@@ -4995,14 +5003,6 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 			break;
 		}
 
-#ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING
-		/* If the pagetables are shared, there is nothing to do */
-		if (ptdesc_pmd_is_shared(virt_to_ptdesc(dst_pte))) {
-			addr |= last_addr_mask;
-			continue;
-		}
-#endif
-
 		dst_ptl = huge_pte_lock(h, dst, dst_pte);
 		src_ptl = huge_pte_lockptr(h, src, src_pte);
 		spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index da67d35cd954..405f2d72f204 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -115,8 +115,7 @@ struct vm_area_struct *find_vma_and_prepare_anon(struct mm_struct *mm,
 	vma = vma_lookup(mm, addr);
 	if (!vma)
 		vma = ERR_PTR(-ENOENT);
-	else if (!(vma->vm_flags & VM_SHARED) &&
-		 unlikely(anon_vma_prepare(vma)))
+	else if (vma_is_cow_mapping(vma) && unlikely(anon_vma_prepare(vma)))
 		vma = ERR_PTR(-ENOMEM);
 
 	return vma;
@@ -145,7 +144,7 @@ static struct vm_area_struct *uffd_lock_vma(struct mm_struct *mm,
 		 * We know we're going to need an anon rmap, so check that
 		 * early.
 		 */
-		if (!(vma->vm_flags & VM_SHARED) && unlikely(!vma_has_anon_rmap(vma)))
+		if (vma_is_cow_mapping(vma) && unlikely(!vma_has_anon_rmap(vma)))
 			vma_end_read(vma);
 		else
 			return vma;