打印函數指針指向的函數名：

printk(KERN_ERR "%s: func %pS is at address: %px\n", __func__, hdev->send, hdev->send);

打印當前函數的調用者的函數名：

printk(KERN_ERR "%s: the func's caller is %pS\n", __func__, __builtin_return_address(0));