diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index 4107dbc..c2578e1 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -48,7 +48,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
 
 	start = untagged_addr(start);
 
-	down_read(&mm->mmap_sem);
+	mmap_read_lock(mm);
 	locked = 1;
 	vma = find_vma_intersection(mm, start, start + 1);
 	if (!vma) {
@@ -102,7 +102,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
 	} while (vma && vma->vm_flags & (VM_IO | VM_PFNMAP));
 out:
 	if (locked)
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 	if (!ret)
 		ret = -EFAULT;
 	if (ret > 0)