When a tty is hung up on Linux, the file operations of all open file structures associated with it are replaced with hung_up_tty_fops, which means all subsequen

When a tty is hung up on Linux, the file operations of all open file structures associated with it are replaced with hung_up_tty_fops, which means all subsequent read(2) returns 0 (EOF), write(2) returns EIO and ioctl(2) returns ENOTTY or EIO. This is basically a tty-specific implementation of revoke(2). Also, when the session leader exits on Linux, the kernel does send SIGHUP and SIGCONT to session leader's process group and the foreground process group (this is in tty_signal_session_leader()).