diff --git a/src/userprog/exception.c b/src/userprog/exception.c
index 84de825..edde441 100644
--- a/src/userprog/exception.c
+++ b/src/userprog/exception.c
@@ -181,11 +181,11 @@ page_fault (struct intr_frame *f)
   /* If the page fault occurred in kernel mode,  then we intentionally indicate
      a fault (for get_user() etc). */
   if (!user)
-  {
-    f->eip = (void *)f->eax;
-    f->eax = 0xffffffff;
-    return;
-  }
+    {
+      f->eip = (void *)f->eax;
+      f->eax = 0xffffffff;
+      return;
+    }
 
 
   /* To implement virtual memory, delete the rest of the function
diff --git a/src/vm/frame.c b/src/vm/frame.c
index 1a6c9a1..6a4e2cd 100644
--- a/src/vm/frame.c
+++ b/src/vm/frame.c
@@ -241,6 +241,7 @@ frame_owner_insert (void *frame, struct thread *owner)
   struct frame_owner *frame_owner = malloc (sizeof (struct frame_owner));
   if (frame_owner == NULL)
     return false;
+
   frame_owner->owner = owner;
   list_push_back (&frame_metadata->owners, &frame_owner->elem);
   return true;
@@ -263,6 +264,7 @@ frame_owner_remove (void *frame, struct thread *owner)
     {
       struct frame_owner *frame_owner
           = list_entry (oe, struct frame_owner, elem);
+
       oe = list_next (oe);
       if (frame_owner->owner == owner)
         {
@@ -284,6 +286,7 @@ frame_metadata_find (void *frame)
   struct hash_elem *e = hash_find (&frame_table, &key_metadata.hash_elem);
   if (e == NULL)
     return NULL;
+
   return hash_entry (e, struct frame_metadata, hash_elem);
 }