message: initialize stack with 0xAC
diff: @@ -129,7 +129,7 @@ impl TaskStacks {
  ptr::write_bytes(
  (virt_addr + KERNEL_STACK_SIZE + DEFAULT_STACK_SIZE + 3 * BasePageSize::SIZE)
  as *mut u8,
  - 0,
  + 0xAC,
  user_stack_size,
  );
  }
  