diff --git a/mm/memory.c b/mm/memory.c
index f64cbf9..ee29259 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2673,7 +2673,7 @@
 	write = (vma->vm_flags & VM_WRITE) != 0;
 	BUG_ON(addr >= end);
 	BUG_ON(end > vma->vm_end);
-	len = (end+PAGE_SIZE-1)/PAGE_SIZE-addr/PAGE_SIZE;
+	len = DIV_ROUND_UP(end, PAGE_SIZE) - addr/PAGE_SIZE;
 	ret = get_user_pages(current, current->mm, addr,
 			len, write, 0, NULL, NULL);
 	if (ret < 0)