diff --git a/gradelib.py b/gradelib.py
index 57618b9..f0d4934 100644
--- a/gradelib.py
+++ b/gradelib.py
@@ -208,8 +208,8 @@ def assert_lines_match(text, *regexps, **kw):
         msg.append("...")
     if bad:
         msg.append("unexpected lines in output")
-    # for r in regexps:
-        # msg.append(color("red", "MISSING") + " '%s'" % r)
+    for r in regexps:
+        msg.append(color("red", "MISSING") + " '%s'" % r)
     raise AssertionError("\n".join(msg))
 
 ##################################################################
diff --git a/kernel/vm.c b/kernel/vm.c
index 7623c11..5b4bfb1 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -645,36 +645,27 @@ copyinstr(pagetable_t pagetable, char *dst, uint64 srcva, uint64 max)
 #ifdef LAB_PGTBL
 void vmprint(pagetable_t pagetable);
 
-static void print_pte_flags(pte_t pte) {
-  if (pte & PTE_R) printf("R");
-  if (pte & PTE_W) printf("W");
-  if (pte & PTE_X) printf("X");
-  if (pte & PTE_U) printf("U");
-}
-
 static void vmprint_recursive(pagetable_t pagetable, int level, uint64 va_base) {
   for (int i = 0; i < 512; i++) {
     pte_t pte = pagetable[i];
     if (pte & PTE_V) {
       uint64 pa = PTE2PA(pte);
+      uint64 va = va_base + ((uint64)i << (12 + 9 * (2 - level)));
 
       for (int j = 0; j < level; j++)
         printf(" ..");
-
-      printf("%d: pte %p pa %p", i, (void*)pte, (void*)pa);
-
-      // 如果是叶子节点，打印 va 和 flags
-      if ((pte & (PTE_R | PTE_W | PTE_X)) != 0) {
-        uint64 va = va_base + ((uint64)i << (9 * (2 - level)));
-        printf(" va %p flags ", (void*)va);
-        print_pte_flags(pte);
+      
+      if (level > 0)
+        printf(" ");
+      if (level == 0) {
+      printf(" ..%p\n", (void*)va);
+      } else {
+      printf("..%p\n", (void*)va);
       }
-      printf("\n");
 
       // 不是叶子节点，递归下一级页表
       if ((pte & (PTE_R | PTE_W | PTE_X)) == 0) {
-        vmprint_recursive((pagetable_t)pa, level + 1,
-                          va_base + ((uint64)i << (9 * (2 - level))));
+        vmprint_recursive((pagetable_t)pa, level + 1, va);
       }
     }
   }