diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index f542a32e82f551ca749a8b55f14a546eb3b47f7d..6e84c46180ecd9cad7485a38fbc56dcfafe18923 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4314,10 +4314,20 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 	struct page *page;
 
 	if (!*pagep) {
-		ret = -ENOMEM;
+		/* If a page already exists, then it's UFFDIO_COPY for
+		 * a non-missing case. Return -EEXIST.
+		 */
+		if (vm_shared &&
+		    hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) {
+			ret = -EEXIST;
+			goto out;
+		}
+
 		page = alloc_huge_page(dst_vma, dst_addr, 0);
-		if (IS_ERR(page))
+		if (IS_ERR(page)) {
+			ret = -ENOMEM;
 			goto out;
+		}
 
 		ret = copy_huge_page_from_user(page,
 						(const void __user *) src_addr,