From 8f432a0a12cc5d5719480a4b1030ae91ed3e7568 Mon Sep 17 00:00:00 2001
From: Andrea Arcangeli <aarcange@redhat.com>
Date: Mon, 31 Oct 2011 17:08:22 -0700
Subject: [PATCH] --- yaml --- r: 272138 b: refs/heads/master c:
 ebed48460be5abd86d9a24fa7c66378e58109f30 h: refs/heads/master v: v3

---
 [refs]            | 2 +-
 trunk/mm/mremap.c | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index 933ca4fc9f65..bdffff7c9de8 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6661672053aee709d93f5dbd7887c789364c11d4
+refs/heads/master: ebed48460be5abd86d9a24fa7c66378e58109f30
diff --git a/trunk/mm/mremap.c b/trunk/mm/mremap.c
index 506fa44403df..195e866568e0 100644
--- a/trunk/mm/mremap.c
+++ b/trunk/mm/mremap.c
@@ -141,9 +141,10 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
 	for (; old_addr < old_end; old_addr += extent, new_addr += extent) {
 		cond_resched();
 		next = (old_addr + PMD_SIZE) & PMD_MASK;
-		if (next - 1 > old_end)
-			next = old_end;
+		/* even if next overflowed, extent below will be ok */
 		extent = next - old_addr;
+		if (extent > old_end - old_addr)
+			extent = old_end - old_addr;
 		old_pmd = get_old_pmd(vma->vm_mm, old_addr);
 		if (!old_pmd)
 			continue;