--- uksm-4.4.patch	2018-03-05 14:24:36.000000000 +0800
+++ uksm-4.4.74+.patch	2018-03-05 14:34:44.000000000 +0800
@@ -1223,7 +1223,7 @@
  			vma_gap_update(next);
 -		else
 +		} else {
- 			mm->highest_vm_end = end;
+ 			VM_WARN_ON(mm->highest_vm_end != vm_end_gap(vma));
 +		}
 +	} else {
 +		if (next && !insert)