mm: mincore: add hwpoison page handle

When the encountered pte is a swap entry, the current code handles two
cases: migration and normal swapentry, but we have a third case: hwpoison
page.

This patch adds hwpoison page handle, consider hwpoison page incore as
same as migration.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NWeijie Yang <weijie.yang@samsung.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/mincore.c

@@ -137,8 +137,11 @@ static void mincore_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 		} else { /* pte is a swap entry */
 			swp_entry_t entry = pte_to_swp_entry(pte);
 
-			if (is_migration_entry(entry)) {
-				/* migration entries are always uptodate */
+			if (non_swap_entry(entry)) {
+				/*
+				 * migration or hwpoison entries are always
+				 * uptodate
+				 */
 				*vec = 1;
 			} else {
 #ifdef CONFIG_SWAP