diff --git a/src/userprog/process.c b/src/userprog/process.c
index e1200bc..ddd1997 100644
--- a/src/userprog/process.c
+++ b/src/userprog/process.c
@@ -65,13 +65,10 @@ process_execute (const char *cmd)
   char *cmd_copy;
   tid_t tid;
   
-  struct process_start_data *data = malloc (sizeof (struct process_start_data));
-  if (data == NULL)
-    {
-      return TID_ERROR;
-    }
-  sema_init (&data->loaded, 0);
-  data->success = false;
+  struct process_start_data data;
+
+  sema_init (&data.loaded, 0);
+  data.success = false;
 
   /* Make a copy of command.
      Otherwise there's a race between the caller and load(). */
@@ -85,7 +82,7 @@ process_execute (const char *cmd)
 
   /* Retrieve first argument of command, which is the file name
      of the process. */
-  char *file_name = strtok_r (cmd_copy, " ", &data->cmd_saveptr);
+  char *file_name = strtok_r (cmd_copy, " ", &data.cmd_saveptr);
 
   /* NOTE: Currently, the file being executed is closed in load () and then
           reopened here. Because load is an exported public function, this
@@ -100,19 +97,18 @@ process_execute (const char *cmd)
   /* Create a new thread to execute the command, by initializing
      it running the function 'start_process' with the appropriate
      arguments. For details of arguments, see 'start_process'. */
-  data->cmd = cmd_copy;
-  strlcpy (data->file_name, file_name, FNAME_MAX_LEN + 1);
+  data.cmd = cmd_copy;
+  strlcpy (data.file_name, file_name, FNAME_MAX_LEN + 1);
 
-  tid = thread_create (file_name, PRI_DEFAULT, start_process, data);
+  tid = thread_create (file_name, PRI_DEFAULT, start_process, &data);
   if (tid == TID_ERROR)
     palloc_free_page (cmd_copy);
   else
     {
-      sema_down (&data->loaded);
-      if (!data->success)
+      sema_down (&data.loaded);
+      if (!data.success)
         tid = TID_ERROR;
     }
-  free (data);
   return tid;
 }