diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index b645c47501b42cc4765073fa6a5d2d2bfaf60396..3b96f18593b392b8680c4e3dd6e5f188c5001c65 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -677,7 +677,7 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
 	if (mi < 0)
 		return -EINVAL;
 
-	requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+	requested_pages = vma_pages(vma);
 	actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
 			+ idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
 	if (requested_pages > actual_pages)