Listing 2. A Really Nasty Test Bug

    case 2: // /dev/echo
        return echoRead(Inode, userBuffer, bufSiz,
                        offset);
        break;
    case 3: // status
        return statusRead(Inode, userBuffer, bufSiz,
                          offset);
        break;
    case 4:
                // Should never get here.  The open
                // hangs.
                return -EINVAL;
        break;

    case 5: // Okay, start overwriting everything
        printk("About to go ka-boom!\n");
        memset(NULL, 0,0xffffffff);
        break;
    } // switch

    printk("%s: Error!  Invalid minor device %d!\n",
           GENTEST_MODULE_NAME, MINOR(Inode->i_rdev));
    return (-EINVAL);
} // gRead