Пример #1
0
static void change_termios(struct tty_struct * tty, struct termios * new_termios)
{
	int canon_change;
	struct termios old_termios = *tty->termios;
	struct tty_ldisc *ld;
	
	/*
	 *	Perform the actual termios internal changes under lock.
	 */
	 

	/* FIXME: we need to decide on some locking/ordering semantics
	   for the set_termios notification eventually */
	down(&tty->termios_sem);

	*tty->termios = *new_termios;
	unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
	canon_change = (old_termios.c_lflag ^ tty->termios->c_lflag) & ICANON;
	if (canon_change) {
		memset(&tty->read_flags, 0, sizeof tty->read_flags);
		tty->canon_head = tty->read_tail;
		tty->canon_data = 0;
		tty->erasing = 0;
	}
	
	
	if (canon_change && !L_ICANON(tty) && tty->read_cnt)
		/* Get characters left over from canonical mode. */
		wake_up_interruptible(&tty->read_wait);

	/* See if packet mode change of state. */

	if (tty->link && tty->link->packet) {
		int old_flow = ((old_termios.c_iflag & IXON) &&
				(old_termios.c_cc[VSTOP] == '\023') &&
				(old_termios.c_cc[VSTART] == '\021'));
		int new_flow = (I_IXON(tty) &&
				STOP_CHAR(tty) == '\023' &&
				START_CHAR(tty) == '\021');
		if (old_flow != new_flow) {
			tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
			if (new_flow)
				tty->ctrl_status |= TIOCPKT_DOSTOP;
			else
				tty->ctrl_status |= TIOCPKT_NOSTOP;
			wake_up_interruptible(&tty->link->read_wait);
		}
	}
	   
	if (tty->driver->set_termios)
		(*tty->driver->set_termios)(tty, &old_termios);

	ld = tty_ldisc_ref(tty);
	if (ld != NULL) {
		if (ld->set_termios)
			(ld->set_termios)(tty, &old_termios);
		tty_ldisc_deref(ld);
	}
	up(&tty->termios_sem);
}
Пример #2
0
/* Insert the contents of the selection buffer into the
 * queue of the tty associated with the current console.
 * Invoked by ioctl().
 */
int paste_selection(struct tty_struct *tty)
{
	struct vt_struct *vt = (struct vt_struct *) tty->driver_data;
	int	pasted = 0, count;
	struct  tty_ldisc *ld;
	DECLARE_WAITQUEUE(wait, current);

	acquire_console_sem();
	poke_blanked_console();
	release_console_sem();

	ld = tty_ldisc_ref_wait(tty);
	
	add_wait_queue(&vt->paste_wait, &wait);
	while (sel_buffer && sel_buffer_lth > pasted) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (test_bit(TTY_THROTTLED, &tty->flags)) {
			schedule();
			continue;
		}
		count = sel_buffer_lth - pasted;
		count = min(count, tty->ldisc.receive_room(tty));
		tty->ldisc.receive_buf(tty, sel_buffer + pasted, NULL, count);
		pasted += count;
	}
	remove_wait_queue(&vt->paste_wait, &wait);
	current->state = TASK_RUNNING;

	tty_ldisc_deref(ld);
	return 0;
}
Пример #3
0
void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
{
	struct uart_state *state = uport->state;
	struct tty_port *port = &state->port;
	struct tty_ldisc *ld = tty_ldisc_ref(port->tty);
	struct pps_event_time ts;

	if (ld && ld->ops->dcd_change)
		pps_get_ts(&ts);

	uport->icount.dcd++;
#ifdef CONFIG_HARD_PPS
	if ((uport->flags & UPF_HARDPPS_CD) && status)
		hardpps();
#endif

	if (port->flags & ASYNC_CHECK_CD) {
		if (status)
			wake_up_interruptible(&port->open_wait);
		else if (port->tty)
			tty_hangup(port->tty);
	}

	if (ld && ld->ops->dcd_change)
		ld->ops->dcd_change(port->tty, status, &ts);
	if (ld)
		tty_ldisc_deref(ld);
}
Пример #4
0
void tty_ldisc_hangup(struct tty_struct *tty)
{
	struct tty_ldisc *ld;
	int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
	int err = 0;

	/*
	 * FIXME! What are the locking issues here? This may me overdoing
	 * things... This question is especially important now that we've
	 * removed the irqlock.
	 */
	ld = tty_ldisc_ref(tty);
	if (ld != NULL) {
		/* We may have no line discipline at this point */
		if (ld->ops->flush_buffer)
			ld->ops->flush_buffer(tty);
		tty_driver_flush_buffer(tty);
		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
		    ld->ops->write_wakeup)
			ld->ops->write_wakeup(tty);
		if (ld->ops->hangup)
			ld->ops->hangup(tty);
		tty_ldisc_deref(ld);
	}
	/*
	 * FIXME: Once we trust the LDISC code better we can wait here for
	 * ldisc completion and fix the driver call race
	 */
	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
	wake_up_interruptible_poll(&tty->read_wait, POLLIN);
	/*
	 * Shutdown the current line discipline, and reset it to
	 * N_TTY if need be.
	 *
	 * Avoid racing set_ldisc or tty_ldisc_release
	 */
	mutex_lock(&tty->ldisc_mutex);
	tty_ldisc_halt(tty);
	/* At this point we have a closed ldisc and we want to
	   reopen it. We could defer this to the next open but
	   it means auditing a lot of other paths so this is
	   a FIXME */
	if (tty->ldisc) {	/* Not yet closed */
		if (reset == 0) {
			tty_ldisc_reinit(tty, tty->termios->c_line);
			err = tty_ldisc_open(tty, tty->ldisc);
		}
		/* If the re-open fails or we reset then go to N_TTY. The
		   N_TTY open cannot fail */
		if (reset || err) {
			tty_ldisc_reinit(tty, N_TTY);
			WARN_ON(tty_ldisc_open(tty, tty->ldisc));
		}
		tty_ldisc_enable(tty);
	}
	mutex_unlock(&tty->ldisc_mutex);
	if (reset)
		tty_reset_termios(tty);
}
static void flush_to_ldisc(struct work_struct *work)
{
	struct tty_struct *tty =
		container_of(work, struct tty_struct, buf.work);
	unsigned long 	flags;
	struct tty_ldisc *disc;

	disc = tty_ldisc_ref(tty);
	if (disc == NULL)	/*  !TTY_LDISC */
		return;

	spin_lock_irqsave(&tty->buf.lock, flags);

	if (!test_and_set_bit(TTY_FLUSHING, &tty->flags)) {
		struct tty_buffer *head;
		while ((head = tty->buf.head) != NULL) {
			int count;
			char *char_buf;
			unsigned char *flag_buf;

			count = head->commit - head->read;
			if (!count) {
				if (head->next == NULL)
					break;
				tty->buf.head = head->next;
				tty_buffer_free(tty, head);
				continue;
			}
			/* Ldisc or user is trying to flush the buffers
			   we are feeding to the ldisc, stop feeding the
			   line discipline as we want to empty the queue */
			if (test_bit(TTY_FLUSHPENDING, &tty->flags))
				break;
			if (!tty->receive_room)
				break;
			if (count > tty->receive_room)
				count = tty->receive_room;
			char_buf = head->char_buf_ptr + head->read;
			flag_buf = head->flag_buf_ptr + head->read;
			head->read += count;
			spin_unlock_irqrestore(&tty->buf.lock, flags);
			disc->ops->receive_buf(tty, char_buf,
							flag_buf, count);
			spin_lock_irqsave(&tty->buf.lock, flags);
		}
		clear_bit(TTY_FLUSHING, &tty->flags);
	}

	/* We may have a deferred request to flush the input buffer,
	   if so pull the chain under the lock and empty the queue */
	if (test_bit(TTY_FLUSHPENDING, &tty->flags)) {
		__tty_buffer_flush(tty);
		clear_bit(TTY_FLUSHPENDING, &tty->flags);
		wake_up(&tty->read_wait);
	}
	spin_unlock_irqrestore(&tty->buf.lock, flags);

	tty_ldisc_deref(disc);
}
Пример #6
0
/**
 *	tty_set_termios		-	update termios values
 *	@tty: tty to update
 *	@new_termios: desired new value
 *
 *	Perform updates to the termios values set on this terminal. There
 *	is a bit of layering violation here with n_tty in terms of the
 *	internal knowledge of this function.
 *
 *	Locking: termios_mutex
 */
int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
{
	struct ktermios old_termios;
	struct tty_ldisc *ld;
	unsigned long flags;

	/*
	 *	Perform the actual termios internal changes under lock.
	 */


	/* FIXME: we need to decide on some locking/ordering semantics
	   for the set_termios notification eventually */
	mutex_lock(&tty->termios_mutex);
	old_termios = *tty->termios;
	*tty->termios = *new_termios;
	unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);

	/* See if packet mode change of state. */
	if (tty->link && tty->link->packet) {
		int extproc = (old_termios.c_lflag & EXTPROC) |
				(tty->termios->c_lflag & EXTPROC);
		int old_flow = ((old_termios.c_iflag & IXON) &&
				(old_termios.c_cc[VSTOP] == '\023') &&
				(old_termios.c_cc[VSTART] == '\021'));
		int new_flow = (I_IXON(tty) &&
				STOP_CHAR(tty) == '\023' &&
				START_CHAR(tty) == '\021');
		if ((old_flow != new_flow) || extproc) {
			spin_lock_irqsave(&tty->ctrl_lock, flags);
			if (old_flow != new_flow) {
				tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
				if (new_flow)
					tty->ctrl_status |= TIOCPKT_DOSTOP;
				else
					tty->ctrl_status |= TIOCPKT_NOSTOP;
			}
			if (extproc)
				tty->ctrl_status |= TIOCPKT_IOCTL;
			spin_unlock_irqrestore(&tty->ctrl_lock, flags);
			wake_up_interruptible(&tty->link->read_wait);
		}
	}

	if (tty->ops->set_termios)
		(*tty->ops->set_termios)(tty, &old_termios);
	else
		tty_termios_copy_hw(tty->termios, &old_termios);

	ld = tty_ldisc_ref(tty);
	if (ld != NULL) {
		if (ld->ops->set_termios)
			(ld->ops->set_termios)(tty, &old_termios);
		tty_ldisc_deref(ld);
	}
	mutex_unlock(&tty->termios_mutex);
	return 0;
}
Пример #7
0
void tty_ldisc_flush(struct tty_struct *tty)
{
	struct tty_ldisc *ld = tty_ldisc_ref(tty);
	if (ld) {
		if (ld->ops->flush_buffer)
			ld->ops->flush_buffer(tty);
		tty_ldisc_deref(ld);
	}
	tty_buffer_flush(tty);
}
Пример #8
0
static void pty_flush_buffer(struct tty_struct *tty)
{
	struct tty_struct *to = tty->link;
	struct tty_ldisc *ld;

	if (!to)
		return;

	ld = tty_ldisc_ref(to);
	tty_buffer_flush(to, ld);
	if (ld)
		tty_ldisc_deref(ld);

	if (to->packet) {
		spin_lock_irq(&tty->ctrl_lock);
		tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
		wake_up_interruptible(&to->read_wait);
		spin_unlock_irq(&tty->ctrl_lock);
	}
}
Пример #9
0
/**
 * usb_serial_handle_dcd_change - handle a change of carrier detect state
 * @port: usb-serial port
 * @tty: tty for the port
 * @status: new carrier detect status, nonzero if active
 */
void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
				struct tty_struct *tty, unsigned int status)
{
	struct tty_port *port = &usb_port->port;

	dev_dbg(&usb_port->dev, "%s - status %d\n", __func__, status);

	if (tty) {
		struct tty_ldisc *ld = tty_ldisc_ref(tty);

		if (ld) {
			if (ld->ops->dcd_change)
				ld->ops->dcd_change(tty, status);
			tty_ldisc_deref(ld);
		}
	}

	if (status)
		wake_up_interruptible(&port->open_wait);
	else if (tty && !C_CLOCAL(tty))
		tty_hangup(tty);
}
Пример #10
0
static int tty_port_default_receive_buf(struct tty_port *port,
					const unsigned char *p,
					const unsigned char *f, size_t count)
{
	int ret;
	struct tty_struct *tty;
	struct tty_ldisc *disc;

	tty = READ_ONCE(port->itty);
	if (!tty)
		return 0;

	disc = tty_ldisc_ref(tty);
	if (!disc)
		return 0;

	ret = tty_ldisc_receive_buf(disc, p, (char *)f, count);

	tty_ldisc_deref(disc);

	return ret;
}
Пример #11
0
static int set_termios(struct tty_struct * tty, void __user *arg, int opt)
{
	struct termios tmp_termios;
	struct tty_ldisc *ld;
	int retval = tty_check_change(tty);

	if (retval)
		return retval;

	if (opt & TERMIOS_TERMIO) {
		memcpy(&tmp_termios, tty->termios, sizeof(struct termios));
		if (user_termio_to_kernel_termios(&tmp_termios,
						(struct termio __user *)arg))
			return -EFAULT;
	} else {
		if (user_termios_to_kernel_termios(&tmp_termios,
						(struct termios __user *)arg))
			return -EFAULT;
	}

	ld = tty_ldisc_ref(tty);
	
	if (ld != NULL) {
		if ((opt & TERMIOS_FLUSH) && ld->flush_buffer)
			ld->flush_buffer(tty);
		tty_ldisc_deref(ld);
	}
	
	if (opt & TERMIOS_WAIT) {
		tty_wait_until_sent(tty, 0);
		if (signal_pending(current))
			return -EINTR;
	}

	change_termios(tty, &tmp_termios);
	return 0;
}
Пример #12
0
/** \<\<private\>\> Read function for TTY
 * @TODO: Why is this copied here from kernel?
 *
 * @param *file   - pointer to file we wanted to read from 
 * @param *buf    - pointer to buffer in kernelspace witch will be filled with data 
 * @param count   - buffer size
 * @param *ppos - pointer to file offset
 *
 * @return Amount of bytes read or error 
 */
static ssize_t proxyfs_tty_real_file_tty_read(struct file * file, char *buf, size_t count, loff_t *ppos)
{
         int i;
         struct tty_struct * tty;
         struct inode *inode;
         struct tty_ldisc *ld = NULL;
	 int state;
 
         tty = (struct tty_struct *)file->private_data;
         inode = file->f_path.dentry->d_inode;
         //if (tty_paranoia_check(tty, inode, "tty_read"))
         //        return -EIO;
         if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
                 return -EIO;
 
         /* We not want to wait for the line discipline to sort out in this
            situation */
         ld = tty_ldisc_ref(tty);
	 if(ld){
	        lock_kernel();
        	if (ld->ops->read){
			state = current->state;
                	i = (ld->ops->read)(tty,file,buf,count);
			current->state = state;
		}
	        else
        	         i = -EIO;
	        tty_ldisc_deref(ld);
        	unlock_kernel();
         	if (i > 0)
                 	inode->i_atime = current_fs_time(inode->i_sb);
		return i;
	 }
	 else
		 return -EAGAIN;
}
Пример #13
0
void tty_ldisc_hangup(struct tty_struct *tty)
{
	struct tty_ldisc *ld;
	int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
	int err = 0;

	/*
	 * FIXME! What are the locking issues here? This may me overdoing
	 * things... This question is especially important now that we've
	 * removed the irqlock.
	 */
	ld = tty_ldisc_ref(tty);
	if (ld != NULL) {
		/* We may have no line discipline at this point */
		if (ld->ops->flush_buffer)
			ld->ops->flush_buffer(tty);
		tty_driver_flush_buffer(tty);
		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
		    ld->ops->write_wakeup)
			ld->ops->write_wakeup(tty);
		if (ld->ops->hangup)
			ld->ops->hangup(tty);
		tty_ldisc_deref(ld);
	}
	/*
	 * FIXME: Once we trust the LDISC code better we can wait here for
	 * ldisc completion and fix the driver call race
	 */
	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
	wake_up_interruptible_poll(&tty->read_wait, POLLIN);
	/*
	 * Shutdown the current line discipline, and reset it to
	 * N_TTY if need be.
	 *
	 * Avoid racing set_ldisc or tty_ldisc_release
	 */
	mutex_lock(&tty->ldisc_mutex);

	/*
	 * this is like tty_ldisc_halt, but we need to give up
	 * the BTM before calling cancel_work_sync, which may
	 * need to wait for another function taking the BTM
	 */
	clear_bit(TTY_LDISC, &tty->flags);
	tty_unlock(tty);
	cancel_work_sync(&tty->port->buf.work);
	mutex_unlock(&tty->ldisc_mutex);
retry:
	tty_lock(tty);
	mutex_lock(&tty->ldisc_mutex);

	/* At this point we have a closed ldisc and we want to
	   reopen it. We could defer this to the next open but
	   it means auditing a lot of other paths so this is
	   a FIXME */
	if (tty->ldisc) {	/* Not yet closed */
		if (atomic_read(&tty->ldisc->users) != 1) {
			char cur_n[TASK_COMM_LEN], tty_n[64];
			long timeout = 3 * HZ;
			tty_unlock(tty);

			while (tty_ldisc_wait_idle(tty, timeout) == -EBUSY) {
				timeout = MAX_SCHEDULE_TIMEOUT;
				printk_ratelimited(KERN_WARNING
					"%s: waiting (%s) for %s took too long, but we keep waiting...\n",
					__func__, get_task_comm(cur_n, current),
					tty_name(tty, tty_n));
			}
			mutex_unlock(&tty->ldisc_mutex);
			goto retry;
		}

		if (reset == 0) {

			if (!tty_ldisc_reinit(tty, tty->termios.c_line))
				err = tty_ldisc_open(tty, tty->ldisc);
			else
				err = 1;
		}
		/* If the re-open fails or we reset then go to N_TTY. The
		   N_TTY open cannot fail */
		if (reset || err) {
			BUG_ON(tty_ldisc_reinit(tty, N_TTY));
			WARN_ON(tty_ldisc_open(tty, tty->ldisc));
		}
		tty_ldisc_enable(tty);
	}
	mutex_unlock(&tty->ldisc_mutex);
	if (reset)
		tty_reset_termios(tty);
}
Пример #14
0
int tty_set_ldisc(struct tty_struct *tty, int ldisc)
{
	int retval;
	struct tty_ldisc o_ldisc, new_ldisc;
	int work;
	unsigned long flags;
	struct tty_struct *o_tty;

restart:
	/* This is a bit ugly for now but means we can break the 'ldisc
	   is part of the tty struct' assumption later */
	retval = tty_ldisc_get(ldisc, &new_ldisc);
	if (retval)
		return retval;

	/*
	 *	Problem: What do we do if this blocks ?
	 */

	tty_wait_until_sent(tty, 0);

	if (tty->ldisc.ops->num == ldisc) {
		tty_ldisc_put(new_ldisc.ops);
		return 0;
	}

	/*
	 *	No more input please, we are switching. The new ldisc
	 *	will update this value in the ldisc open function
	 */

	tty->receive_room = 0;

	o_ldisc = tty->ldisc;
	o_tty = tty->link;

	/*
	 *	Make sure we don't change while someone holds a
	 *	reference to the line discipline. The TTY_LDISC bit
	 *	prevents anyone taking a reference once it is clear.
	 *	We need the lock to avoid racing reference takers.
	 *
	 *	We must clear the TTY_LDISC bit here to avoid a livelock
	 *	with a userspace app continually trying to use the tty in
	 *	parallel to the change and re-referencing the tty.
	 */
	clear_bit(TTY_LDISC, &tty->flags);
	if (o_tty)
		clear_bit(TTY_LDISC, &o_tty->flags);

	spin_lock_irqsave(&tty_ldisc_lock, flags);
	if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) {
		if (tty->ldisc.refcount) {
			/* Free the new ldisc we grabbed. Must drop the lock
			   first. */
			spin_unlock_irqrestore(&tty_ldisc_lock, flags);
			tty_ldisc_put(new_ldisc.ops);
			/*
			 * There are several reasons we may be busy, including
			 * random momentary I/O traffic. We must therefore
			 * retry. We could distinguish between blocking ops
			 * and retries if we made tty_ldisc_wait() smarter.
			 * That is up for discussion.
			 */
			if (wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0)
				return -ERESTARTSYS;
			goto restart;
		}
		if (o_tty && o_tty->ldisc.refcount) {
			spin_unlock_irqrestore(&tty_ldisc_lock, flags);
			tty_ldisc_put(o_tty->ldisc.ops);
			if (wait_event_interruptible(tty_ldisc_wait, o_tty->ldisc.refcount == 0) < 0)
				return -ERESTARTSYS;
			goto restart;
		}
	}
	/*
	 *	If the TTY_LDISC bit is set, then we are racing against
	 *	another ldisc change
	 */
	if (test_bit(TTY_LDISC_CHANGING, &tty->flags)) {
		struct tty_ldisc *ld;
		spin_unlock_irqrestore(&tty_ldisc_lock, flags);
		tty_ldisc_put(new_ldisc.ops);
		ld = tty_ldisc_ref_wait(tty);
		tty_ldisc_deref(ld);
		goto restart;
	}
	/*
	 *	This flag is used to avoid two parallel ldisc changes. Once
	 *	open and close are fine grained locked this may work better
	 *	as a mutex shared with the open/close/hup paths
	 */
	set_bit(TTY_LDISC_CHANGING, &tty->flags);
	if (o_tty)
		set_bit(TTY_LDISC_CHANGING, &o_tty->flags);
	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
	
	/*
	 *	From this point on we know nobody has an ldisc
	 *	usage reference, nor can they obtain one until
	 *	we say so later on.
	 */

	work = cancel_delayed_work(&tty->buf.work);
	/*
	 * Wait for ->hangup_work and ->buf.work handlers to terminate
	 * MUST NOT hold locks here.
	 */
	flush_scheduled_work();
	/* Shutdown the current discipline. */
	if (o_ldisc.ops->close)
		(o_ldisc.ops->close)(tty);

	/* Now set up the new line discipline. */
	tty_ldisc_assign(tty, &new_ldisc);
	tty_set_termios_ldisc(tty, ldisc);
	if (new_ldisc.ops->open)
		retval = (new_ldisc.ops->open)(tty);
	if (retval < 0) {
		tty_ldisc_put(new_ldisc.ops);
		tty_ldisc_restore(tty, &o_ldisc);
	}
	/* At this point we hold a reference to the new ldisc and a
	   a reference to the old ldisc. If we ended up flipping back
	   to the existing ldisc we have two references to it */

	if (tty->ldisc.ops->num != o_ldisc.ops->num && tty->ops->set_ldisc)
		tty->ops->set_ldisc(tty);

	tty_ldisc_put(o_ldisc.ops);

	/*
	 *	Allow ldisc referencing to occur as soon as the driver
	 *	ldisc callback completes.
	 */

	tty_ldisc_enable(tty);
	if (o_tty)
		tty_ldisc_enable(o_tty);

	/* Restart it in case no characters kick it off. Safe if
	   already running */
	if (work)
		schedule_delayed_work(&tty->buf.work, 1);
	return retval;
}
Пример #15
0
int n_tty_ioctl(struct tty_struct * tty, struct file * file,
		       unsigned int cmd, unsigned long arg)
{
	struct tty_struct * real_tty;
	void __user *p = (void __user *)arg;
	int retval;
	struct tty_ldisc *ld;

	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
	    tty->driver->subtype == PTY_TYPE_MASTER)
		real_tty = tty->link;
	else
		real_tty = tty;

	switch (cmd) {
#ifdef TIOCGETP
		case TIOCGETP:
			return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
		case TIOCSETP:
		case TIOCSETN:
			return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
#endif
#ifdef TIOCGETC
		case TIOCGETC:
			return get_tchars(real_tty, p);
		case TIOCSETC:
			return set_tchars(real_tty, p);
#endif
#ifdef TIOCGLTC
		case TIOCGLTC:
			return get_ltchars(real_tty, p);
		case TIOCSLTC:
			return set_ltchars(real_tty, p);
#endif
		case TCGETS:
			if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
				return -EFAULT;
			return 0;
		case TCSETSF:
			return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);
		case TCSETSW:
			return set_termios(real_tty, p, TERMIOS_WAIT);
		case TCSETS:
			return set_termios(real_tty, p, 0);
		case TCGETA:
			return get_termio(real_tty, p);
		case TCSETAF:
			return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
		case TCSETAW:
			return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
		case TCSETA:
			return set_termios(real_tty, p, TERMIOS_TERMIO);
		case TCXONC:
			retval = tty_check_change(tty);
			if (retval)
				return retval;
			switch (arg) {
			case TCOOFF:
				if (!tty->flow_stopped) {
					tty->flow_stopped = 1;
					stop_tty(tty);
				}
				break;
			case TCOON:
				if (tty->flow_stopped) {
					tty->flow_stopped = 0;
					start_tty(tty);
				}
				break;
			case TCIOFF:
				if (STOP_CHAR(tty) != __DISABLED_CHAR)
					send_prio_char(tty, STOP_CHAR(tty));
				break;
			case TCION:
				if (START_CHAR(tty) != __DISABLED_CHAR)
					send_prio_char(tty, START_CHAR(tty));
				break;
			default:
				return -EINVAL;
			}
			return 0;
		case TCFLSH:
			retval = tty_check_change(tty);
			if (retval)
				return retval;
				
			ld = tty_ldisc_ref(tty);
			switch (arg) {
			case TCIFLUSH:
				if (ld->flush_buffer)
					ld->flush_buffer(tty);
				break;
			case TCIOFLUSH:
				if (ld->flush_buffer)
					ld->flush_buffer(tty);
				/* fall through */
			case TCOFLUSH:
				if (tty->driver->flush_buffer)
					tty->driver->flush_buffer(tty);
				break;
			default:
				tty_ldisc_deref(ld);
				return -EINVAL;
			}
			tty_ldisc_deref(ld);
			return 0;
		case TIOCOUTQ:
			return put_user(tty->driver->chars_in_buffer ?
					tty->driver->chars_in_buffer(tty) : 0,
					(int __user *) arg);
		case TIOCINQ:
			retval = tty->read_cnt;
			if (L_ICANON(tty))
				retval = inq_canon(tty);
			return put_user(retval, (unsigned int __user *) arg);
		case TIOCGLCKTRMIOS:
			if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
				return -EFAULT;
			return 0;

		case TIOCSLCKTRMIOS:
			if (!capable(CAP_SYS_ADMIN))
				return -EPERM;
			if (user_termios_to_kernel_termios(real_tty->termios_locked, (struct termios __user *) arg))
				return -EFAULT;
			return 0;

		case TIOCPKT:
		{
			int pktmode;

			if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
			    tty->driver->subtype != PTY_TYPE_MASTER)
				return -ENOTTY;
			if (get_user(pktmode, (int __user *) arg))
				return -EFAULT;
			if (pktmode) {
				if (!tty->packet) {
					tty->packet = 1;
					tty->link->ctrl_status = 0;
				}
			} else
				tty->packet = 0;
			return 0;
		}
		case TIOCGSOFTCAR:
			return put_user(C_CLOCAL(tty) ? 1 : 0, (int __user *)arg);
		case TIOCSSOFTCAR:
			if (get_user(arg, (unsigned int __user *) arg))
				return -EFAULT;
			down(&tty->termios_sem);
			tty->termios->c_cflag =
				((tty->termios->c_cflag & ~CLOCAL) |
				 (arg ? CLOCAL : 0));
			up(&tty->termios_sem);
			return 0;
		default:
			return -ENOIOCTLCMD;
		}
}
Пример #16
0
static void flush_to_ldisc(struct work_struct *work)
{
    struct tty_struct *tty =
        container_of(work, struct tty_struct, buf.work.work);
    unsigned long 	flags;
    struct tty_ldisc *disc;

    disc = tty_ldisc_ref(tty);
    if (disc == NULL)	/*  !TTY_LDISC */
        return;

    spin_lock_irqsave(&tty->buf.lock, flags);

    if (!test_and_set_bit(TTY_FLUSHING, &tty->flags)) {
        struct tty_buffer *head, *tail = tty->buf.tail;
        int seen_tail = 0;
        while ((head = tty->buf.head) != NULL) {
            int count;
            char *char_buf;
            unsigned char *flag_buf;

            count = head->commit - head->read;
            if (!count) {
                if (head->next == NULL)
                    break;
                /*
                  There's a possibility tty might get new buffer
                  added during the unlock window below. We could
                  end up spinning in here forever hogging the CPU
                  completely. To avoid this let's have a rest each
                  time we processed the tail buffer.
                */
                if (tail == head)
                    seen_tail = 1;
                tty->buf.head = head->next;
                tty_buffer_free(tty, head);
                continue;
            }
            /* Ldisc or user is trying to flush the buffers
               we are feeding to the ldisc, stop feeding the
               line discipline as we want to empty the queue */
            if (test_bit(TTY_FLUSHPENDING, &tty->flags))
                break;
            if (!tty->receive_room || seen_tail) {
                schedule_delayed_work(&tty->buf.work, 1);
                break;
            }
            if (count > tty->receive_room)
                count = tty->receive_room;
            char_buf = head->char_buf_ptr + head->read;
            flag_buf = head->flag_buf_ptr + head->read;
            head->read += count;
            spin_unlock_irqrestore(&tty->buf.lock, flags);
            disc->ops->receive_buf(tty, char_buf,
                                   flag_buf, count);
            spin_lock_irqsave(&tty->buf.lock, flags);
        }
        clear_bit(TTY_FLUSHING, &tty->flags);
    }

    /* We may have a deferred request to flush the input buffer,
       if so pull the chain under the lock and empty the queue */
    if (test_bit(TTY_FLUSHPENDING, &tty->flags)) {
        __tty_buffer_flush(tty);
        clear_bit(TTY_FLUSHPENDING, &tty->flags);
        wake_up(&tty->read_wait);
    }
    spin_unlock_irqrestore(&tty->buf.lock, flags);

    tty_ldisc_deref(disc);
}
Пример #17
0
void tty_ldisc_hangup(struct tty_struct *tty)
{
	struct tty_ldisc *ld;
	int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
	int err = 0;

	tty_ldisc_debug(tty, "closing ldisc: %p\n", tty->ldisc);

	ld = tty_ldisc_ref(tty);
	if (ld != NULL) {
		if (ld->ops->flush_buffer)
			ld->ops->flush_buffer(tty);
		tty_driver_flush_buffer(tty);
		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
		    ld->ops->write_wakeup)
			ld->ops->write_wakeup(tty);
		if (ld->ops->hangup)
			ld->ops->hangup(tty);
		tty_ldisc_deref(ld);
	}

	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
	wake_up_interruptible_poll(&tty->read_wait, POLLIN);

	tty_unlock(tty);

	/*
	 * Shutdown the current line discipline, and reset it to
	 * N_TTY if need be.
	 *
	 * Avoid racing set_ldisc or tty_ldisc_release
	 */
	tty_ldisc_lock_pair(tty, tty->link);
	tty_lock(tty);

	if (tty->ldisc) {

		/* At this point we have a halted ldisc; we want to close it and
		   reopen a new ldisc. We could defer the reopen to the next
		   open but it means auditing a lot of other paths so this is
		   a FIXME */
		if (reset == 0) {

			if (!tty_ldisc_reinit(tty, tty->termios.c_line))
				err = tty_ldisc_open(tty, tty->ldisc);
			else
				err = 1;
		}
		/* If the re-open fails or we reset then go to N_TTY. The
		   N_TTY open cannot fail */
		if (reset || err) {
			BUG_ON(tty_ldisc_reinit(tty, N_TTY));
			WARN_ON(tty_ldisc_open(tty, tty->ldisc));
		}
	}
	tty_ldisc_enable_pair(tty, tty->link);
	if (reset)
		tty_reset_termios(tty);

	tty_ldisc_debug(tty, "re-opened ldisc: %p\n", tty->ldisc);
}
Пример #18
0
void tty_ldisc_hangup(struct tty_struct *tty)
{
	struct tty_ldisc *ld;
	int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
	int err = 0;

	ld = tty_ldisc_ref(tty);
	if (ld != NULL) {
		/* We may have no line discipline at this point */
		if (ld->ops->flush_buffer)
			ld->ops->flush_buffer(tty);
		tty_driver_flush_buffer(tty);
		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
		    ld->ops->write_wakeup)
			ld->ops->write_wakeup(tty);
		if (ld->ops->hangup)
			ld->ops->hangup(tty);
		tty_ldisc_deref(ld);
	}
	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
	wake_up_interruptible_poll(&tty->read_wait, POLLIN);
	/*
	 * Shutdown the current line discipline, and reset it to
	 * N_TTY if need be.
	 *
	 * Avoid racing set_ldisc or tty_ldisc_release
	 */
	mutex_lock(&tty->ldisc_mutex);

	/*
	 * this is like tty_ldisc_halt, but we need to give up
	 * the BTM before calling cancel_delayed_work_sync,
	 * which may need to wait for another function taking the BTM
	 */
	clear_bit(TTY_LDISC, &tty->flags);
	tty_unlock();
	cancel_delayed_work_sync(&tty->buf.work);
	mutex_unlock(&tty->ldisc_mutex);

	tty_lock();
	mutex_lock(&tty->ldisc_mutex);

	if (tty->ldisc) {	/* Not yet closed */
		if (reset == 0) {

			if (!tty_ldisc_reinit(tty, tty->termios->c_line))
				err = tty_ldisc_open(tty, tty->ldisc);
			else
				err = 1;
		}
		/* If the re-open fails or we reset then go to N_TTY. The
		   N_TTY open cannot fail */
		if (reset || err) {
			BUG_ON(tty_ldisc_reinit(tty, N_TTY));
			WARN_ON(tty_ldisc_open(tty, tty->ldisc));
		}
		tty_ldisc_enable(tty);
	}
	mutex_unlock(&tty->ldisc_mutex);
	if (reset)
		tty_reset_termios(tty);
}
Пример #19
0
void jsm_input(struct jsm_channel *ch)
{
	struct jsm_board *bd;
	struct tty_struct *tp;
	struct tty_ldisc *ld;
	u32 rmask;
	u16 head;
	u16 tail;
	int data_len;
	unsigned long lock_flags;
	int flip_len = 0;
	int len = 0;
	int n = 0;
	int s = 0;
	int i = 0;

	jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");

	if (!ch)
		return;

	tp = ch->uart_port.info->tty;

	bd = ch->ch_bd;
	if(!bd)
		return;

	spin_lock_irqsave(&ch->ch_lock, lock_flags);

	/*
	 *Figure the number of characters in the buffer.
	 *Exit immediately if none.
	 */

	rmask = RQUEUEMASK;

	head = ch->ch_r_head & rmask;
	tail = ch->ch_r_tail & rmask;

	data_len = (head - tail) & rmask;
	if (data_len == 0) {
		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
		return;
	}

	jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");

	/*
	 *If the device is not open, or CREAD is off, flush
	 *input data and return immediately.
	 */
	if (!tp ||
		!(tp->termios->c_cflag & CREAD) ) {

		jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
			"input. dropping %d bytes on port %d...\n", data_len, ch->ch_portnum);
		ch->ch_r_head = tail;

		/* Force queue flow control to be released, if needed */
		jsm_check_queue_flow_control(ch);

		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
		return;
	}

	/*
	 * If we are throttled, simply don't read any data.
	 */
	if (ch->ch_flags & CH_STOPI) {
		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
		jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
			"Port %d throttled, not reading any data. head: %x tail: %x\n",
			ch->ch_portnum, head, tail);
		return;
	}

	jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start 2\n");

	/*
	 * If the rxbuf is empty and we are not throttled, put as much
	 * as we can directly into the linux TTY buffer.
	 *
	 */
	flip_len = TTY_FLIPBUF_SIZE;

	len = min(data_len, flip_len);
	len = min(len, (N_TTY_BUF_SIZE - 1) - tp->read_cnt);
	ld = tty_ldisc_ref(tp);

	/*
	 * If we were unable to get a reference to the ld,
	 * don't flush our buffer, and act like the ld doesn't
	 * have any space to put the data right now.
	 */
	if (!ld) {
		len = 0;
	} else {
		/*
		 * If ld doesn't have a pointer to a receive_buf function,
		 * flush the data, then act like the ld doesn't have any
		 * space to put the data right now.
		 */
		if (!ld->receive_buf) {
				ch->ch_r_head = ch->ch_r_tail;
				len = 0;
		}
	}

	if (len <= 0) {
		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
		jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "jsm_input 1\n");
		if (ld)
			tty_ldisc_deref(ld);
		return;
	}

	len = tty_buffer_request_room(tp, len);
	n = len;

	/*
	 * n now contains the most amount of data we can copy,
	 * bounded either by the flip buffer size or the amount
	 * of data the card actually has pending...
	 */
	while (n) {
		s = ((head >= tail) ? head : RQUEUESIZE) - tail;
		s = min(s, n);

		if (s <= 0)
			break;

			/*
			 * If conditions are such that ld needs to see all
			 * UART errors, we will have to walk each character
			 * and error byte and send them to the buffer one at
			 * a time.
			 */

		if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
			for (i = 0; i < s; i++) {
				/*
				 * Give the Linux ld the flags in the
				 * format it likes.
				 */
				if (*(ch->ch_equeue +tail +i) & UART_LSR_BI)
					tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i),  TTY_BREAK);
				else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE)
					tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_PARITY);
				else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE)
					tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_FRAME);
				else
				tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_NORMAL);
			}
		} else {
			tty_insert_flip_string(tp, ch->ch_rqueue + tail, s) ;
		}
		tail += s;
		n -= s;
		/* Flip queue if needed */
		tail &= rmask;
	}

	ch->ch_r_tail = tail & rmask;
	ch->ch_e_tail = tail & rmask;
	jsm_check_queue_flow_control(ch);
	spin_unlock_irqrestore(&ch->ch_lock, lock_flags);

	/* Tell the tty layer its okay to "eat" the data now */
	tty_flip_buffer_push(tp);

	if (ld)
		tty_ldisc_deref(ld);

	jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
}
Пример #20
0
static void flush_to_ldisc(struct work_struct *work)
{
	struct tty_struct *tty =
		container_of(work, struct tty_struct, buf.work);
	unsigned long 	flags;
	struct tty_ldisc *disc;

	disc = tty_ldisc_ref(tty);
	if (disc == NULL)	/*  !TTY_LDISC */
		return;

	spin_lock_irqsave(&tty->buf.lock, flags);

	if (!test_and_set_bit(TTY_FLUSHING, &tty->flags)) {
		struct tty_buffer *head;
		while ((head = tty->buf.head) != NULL) {
			int count;
			char *char_buf;
			unsigned char *flag_buf;
			unsigned int left = 0;
			unsigned int max_space;

			count = head->commit - head->read;
			if (!count) {
				if (head->next == NULL)
					break;
				tty->buf.head = head->next;
				tty_buffer_free(tty, head);
				continue;
			}
			/* Ldisc or user is trying to flush the buffers
			   we are feeding to the ldisc, stop feeding the
			   line discipline as we want to empty the queue */
			if (test_bit(TTY_FLUSHPENDING, &tty->flags))
				break;

			/* update receive room */
			spin_lock(&tty->read_lock);
			if (tty->update_room_in_ldisc) {
				if ((tty->read_cnt == N_TTY_BUF_SIZE - 1) &&
					(tty->receive_room ==
						N_TTY_BUF_SIZE - 1))
					tty->rr_bug++;
				left = N_TTY_BUF_SIZE - tty->read_cnt - 1;
			}
			spin_unlock(&tty->read_lock);

			if (!tty->receive_room)
				break;

			if (tty->update_room_in_ldisc && !left) {
				schedule_work(&tty->buf.work);
				break;
			}

			if (tty->update_room_in_ldisc)
				max_space = min(left, tty->receive_room);
			else
				max_space = tty->receive_room;

			if (count > max_space)
				count = max_space;
			char_buf = head->char_buf_ptr + head->read;
			flag_buf = head->flag_buf_ptr + head->read;
			head->read += count;
			spin_unlock_irqrestore(&tty->buf.lock, flags);
			if(tty->start_debug){
				dbg_log_event(NULL, "f_t_l_d:head->read",head->read, "head->commit", head->commit,
					"receive_room ", tty->receive_room );
			}
			tty->ldisc_cnt += count;
			disc->ops->receive_buf(tty, char_buf,
							flag_buf, count);
			spin_lock_irqsave(&tty->buf.lock, flags);
		}
		clear_bit(TTY_FLUSHING, &tty->flags);
	}

	/* We may have a deferred request to flush the input buffer,
	   if so pull the chain under the lock and empty the queue */
	if (test_bit(TTY_FLUSHPENDING, &tty->flags)) {
		__tty_buffer_flush(tty);
		clear_bit(TTY_FLUSHPENDING, &tty->flags);
		wake_up(&tty->read_wait);
	}
	spin_unlock_irqrestore(&tty->buf.lock, flags);

	tty_ldisc_deref(disc);
}