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Commit 0146b693 authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
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TTY: HVC, use count from tty_port 



Now, count is used from tty_port and protected by tty_port->lock.

n_outbuf is left unprotected in hvc_hangup now, because there is no
point to hold any lock, since other uses are unprotected too.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 85bbc003

drivers/tty/hvc/hvc_console.c

+21 −19
Original line number Diff line number Diff line
@@ -313,18 +313,18 @@ static int hvc_open(struct tty_struct *tty, struct file * filp) 
	if (!(hp = hvc_get_by_index(tty->index)))

		return -ENODEV;



	spin_lock_irqsave(&hp->lock, flags);

	spin_lock_irqsave(&hp->port.lock, flags);

	/* Check and then increment for fast path open. */

	if (hp->count++ > 0) {

	if (hp->port.count++ > 0) {

		spin_unlock_irqrestore(&hp->port.lock, flags);

		/* FIXME why taking a reference here? */

		tty_kref_get(tty);

		spin_unlock_irqrestore(&hp->lock, flags);

		hvc_kick();

		return 0;

	} /* else count == 0 */

	spin_unlock_irqrestore(&hp->port.lock, flags);



	tty->driver_data = hp;

	spin_unlock_irqrestore(&hp->lock, flags);



	tty_port_tty_set(&hp->port, tty);



	if (hp->ops->notifier_add)
@@ -367,10 +367,10 @@ static void hvc_close(struct tty_struct *tty, struct file * filp) 


	hp = tty->driver_data;



	spin_lock_irqsave(&hp->lock, flags);

	spin_lock_irqsave(&hp->port.lock, flags);



	if (--hp->count == 0) {

		spin_unlock_irqrestore(&hp->lock, flags);

	if (--hp->port.count == 0) {

		spin_unlock_irqrestore(&hp->port.lock, flags);

		/* We are done with the tty pointer now. */

		tty_port_tty_set(&hp->port, NULL);
@@ -387,10 +387,10 @@ static void hvc_close(struct tty_struct *tty, struct file * filp) 
		 */

		tty_wait_until_sent_from_close(tty, HVC_CLOSE_WAIT);

	} else {

		if (hp->count < 0)

		if (hp->port.count < 0)

			printk(KERN_ERR "hvc_close %X: oops, count is %d\n",

				hp->vtermno, hp->count);

		spin_unlock_irqrestore(&hp->lock, flags);

				hp->vtermno, hp->port.count);

		spin_unlock_irqrestore(&hp->port.lock, flags);

	}



	tty_kref_put(tty);
@@ -409,24 +409,25 @@ static void hvc_hangup(struct tty_struct *tty) 
	/* cancel pending tty resize work */

	cancel_work_sync(&hp->tty_resize);



	spin_lock_irqsave(&hp->lock, flags);

	spin_lock_irqsave(&hp->port.lock, flags);



	/*

	 * The N_TTY line discipline has problems such that in a close vs

	 * open->hangup case this can be called after the final close so prevent

	 * that from happening for now.

	 */

	if (hp->count <= 0) {

		spin_unlock_irqrestore(&hp->lock, flags);

	if (hp->port.count <= 0) {

		spin_unlock_irqrestore(&hp->port.lock, flags);

		return;

	}



	temp_open_count = hp->count;

	hp->count = 0;

	hp->n_outbuf = 0;

	spin_unlock_irqrestore(&hp->lock, flags);

	temp_open_count = hp->port.count;

	hp->port.count = 0;

	spin_unlock_irqrestore(&hp->port.lock, flags);

	tty_port_tty_set(&hp->port, NULL);



	hp->n_outbuf = 0;



	if (hp->ops->notifier_hangup)

		hp->ops->notifier_hangup(hp, hp->data);
@@ -474,7 +475,8 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count 
	if (!hp)

		return -EPIPE;



	if (hp->count <= 0)

	/* FIXME what's this (unprotected) check for? */

	if (hp->port.count <= 0)

		return -EIO;



	spin_lock_irqsave(&hp->lock, flags);

drivers/tty/hvc/hvc_console.h

+0 −1
Original line number Diff line number Diff line
@@ -49,7 +49,6 @@ struct hvc_struct { 
	struct tty_port port;

	spinlock_t lock;

	int index;

	int count;

	int do_wakeup;

	char *outbuf;

	int outbuf_size;