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Commit d450b5a0 authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
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tty: kref usage for isicom and moxa 



Rather than blindly keep taking krefs we reorder the code in a few places
to pass the tty down to the right place (which is important as from the user
side it is not the case that tty == port->tty in all situations). For the irq
and related paths use the krefs to stop the tty being freed under us.

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4a90f09b

drivers/char/isicom.c

+31 −30
Original line number Diff line number Diff line
@@ -421,17 +421,16 @@ static void isicom_tx(unsigned long _data) 
	if (retries >= 100)

		goto unlock;



	tty = tty_port_tty_get(&port->port);

	if (tty == NULL)

		goto put_unlock;



	for (; count > 0; count--, port++) {

		/* port not active or tx disabled to force flow control */

		if (!(port->port.flags & ASYNC_INITIALIZED) ||

				!(port->status & ISI_TXOK))

			continue;



		tty = port->port.tty;



		if (tty == NULL)

			continue;



		txcount = min_t(short, TX_SIZE, port->xmit_cnt);

		if (txcount <= 0 || tty->stopped || tty->hw_stopped)

			continue;
@@ -489,6 +488,8 @@ static void isicom_tx(unsigned long _data) 
			tty_wakeup(tty);

	}



put_unlock:

	tty_kref_put(tty);

unlock:

	spin_unlock_irqrestore(&isi_card[card].card_lock, flags);

	/*	schedule another tx for hopefully in about 10ms	*/
@@ -547,7 +548,7 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id) 
		return IRQ_HANDLED;

	}



	tty = port->port.tty;

	tty = tty_port_tty_get(&port->port);

	if (tty == NULL) {

		word_count = byte_count >> 1;

		while (byte_count > 1) {
@@ -588,7 +589,7 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id) 
			}



			if (port->port.flags & ASYNC_CTS_FLOW) {

				if (port->port.tty->hw_stopped) {

				if (tty->hw_stopped) {

					if (header & ISI_CTS) {

						port->port.tty->hw_stopped = 0;

						/* start tx ing */
@@ -597,7 +598,7 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id) 
						tty_wakeup(tty);

					}

				} else if (!(header & ISI_CTS)) {

					port->port.tty->hw_stopped = 1;

					tty->hw_stopped = 1;

					/* stop tx ing */

					port->status &= ~(ISI_TXOK | ISI_CTS);

				}
@@ -660,24 +661,21 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id) 
	}

	outw(0x0000, base+0x04); /* enable interrupts */

	spin_unlock(&card->card_lock);

	tty_kref_put(tty);



	return IRQ_HANDLED;

}



static void isicom_config_port(struct isi_port *port)

static void isicom_config_port(struct tty_struct *tty)

{

	struct isi_port *port = tty->driver_data;

	struct isi_board *card = port->card;

	struct tty_struct *tty;

	unsigned long baud;

	unsigned long base = card->base;

	u16 channel_setup, channel = port->channel,

		shift_count = card->shift_count;

	unsigned char flow_ctrl;



	tty = port->port.tty;



	if (tty == NULL)

		return;

	/* FIXME: Switch to new tty baud API */

	baud = C_BAUD(tty);

	if (baud & CBAUDEX) {
@@ -690,7 +688,7 @@ static void isicom_config_port(struct isi_port *port) 


		/* 1,2,3,4 => 57.6, 115.2, 230, 460 kbps resp. */

		if (baud < 1 || baud > 4)

			port->port.tty->termios->c_cflag &= ~CBAUDEX;

			tty->termios->c_cflag &= ~CBAUDEX;

		else

			baud += 15;

	}
@@ -797,8 +795,9 @@ static inline void isicom_setup_board(struct isi_board *bp) 
	spin_unlock_irqrestore(&bp->card_lock, flags);

}



static int isicom_setup_port(struct isi_port *port)

static int isicom_setup_port(struct tty_struct *tty)

{

	struct isi_port *port = tty->driver_data;

	struct isi_board *card = port->card;

	unsigned long flags;
@@ -808,8 +807,7 @@ static int isicom_setup_port(struct isi_port *port) 
		return -ENOMEM;



	spin_lock_irqsave(&card->card_lock, flags);

	if (port->port.tty)

		clear_bit(TTY_IO_ERROR, &port->port.tty->flags);

	clear_bit(TTY_IO_ERROR, &tty->flags);

	if (port->port.count == 1)

		card->count++;
@@ -823,7 +821,7 @@ static int isicom_setup_port(struct isi_port *port) 
		InterruptTheCard(card->base);

	}



	isicom_config_port(port);

	isicom_config_port(tty);

	port->port.flags |= ASYNC_INITIALIZED;

	spin_unlock_irqrestore(&card->card_lock, flags);
@@ -934,8 +932,8 @@ static int isicom_open(struct tty_struct *tty, struct file *filp) 


	port->port.count++;

	tty->driver_data = port;

	port->port.tty = tty;

	error = isicom_setup_port(port);

	tty_port_tty_set(&port->port, tty);

	error = isicom_setup_port(tty);

	if (error == 0)

		error = block_til_ready(tty, filp, port);

	return error;
@@ -955,15 +953,17 @@ static void isicom_shutdown_port(struct isi_port *port) 
	struct isi_board *card = port->card;

	struct tty_struct *tty;



	tty = port->port.tty;

	tty = tty_port_tty_get(&port->port);



	if (!(port->port.flags & ASYNC_INITIALIZED))

	if (!(port->port.flags & ASYNC_INITIALIZED)) {

		tty_kref_put(tty);

		return;

	}



	tty_port_free_xmit_buf(&port->port);

	port->port.flags &= ~ASYNC_INITIALIZED;

	/* 3rd October 2000 : Vinayak P Risbud */

	port->port.tty = NULL;

	tty_port_tty_set(&port->port, NULL);



	/*Fix done by Anil .S on 30-04-2001

	remote login through isi port has dtr toggle problem
@@ -1243,9 +1243,10 @@ static int isicom_tiocmset(struct tty_struct *tty, struct file *file, 
	return 0;

}



static int isicom_set_serial_info(struct isi_port *port,

static int isicom_set_serial_info(struct tty_struct *tty,

					struct serial_struct __user *info)

{

	struct isi_port *port = tty->driver_data;

	struct serial_struct newinfo;

	int reconfig_port;
@@ -1276,7 +1277,7 @@ static int isicom_set_serial_info(struct isi_port *port, 
	if (reconfig_port) {

		unsigned long flags;

		spin_lock_irqsave(&port->card->card_lock, flags);

		isicom_config_port(port);

		isicom_config_port(tty);

		spin_unlock_irqrestore(&port->card->card_lock, flags);

	}

	unlock_kernel();
@@ -1318,7 +1319,7 @@ static int isicom_ioctl(struct tty_struct *tty, struct file *filp, 
		return isicom_get_serial_info(port, argp);



	case TIOCSSERIAL:

		return isicom_set_serial_info(port, argp);

		return isicom_set_serial_info(tty, argp);



	default:

		return -ENOIOCTLCMD;
@@ -1341,7 +1342,7 @@ static void isicom_set_termios(struct tty_struct *tty, 
		return;



	spin_lock_irqsave(&port->card->card_lock, flags);

	isicom_config_port(port);

	isicom_config_port(tty);

	spin_unlock_irqrestore(&port->card->card_lock, flags);



	if ((old_termios->c_cflag & CRTSCTS) &&
@@ -1419,7 +1420,7 @@ static void isicom_hangup(struct tty_struct *tty) 


	port->port.count = 0;

	port->port.flags &= ~ASYNC_NORMAL_ACTIVE;

	port->port.tty = NULL;

	tty_port_tty_set(&port->port, NULL);

	wake_up_interruptible(&port->port.open_wait);

}

drivers/char/moxa.c

+38 −23
Original line number Diff line number Diff line
@@ -205,7 +205,7 @@ static int moxa_tiocmset(struct tty_struct *tty, struct file *file, 
static void moxa_poll(unsigned long);

static void moxa_set_tty_param(struct tty_struct *, struct ktermios *);

static void moxa_setup_empty_event(struct tty_struct *);

static void moxa_shut_down(struct moxa_port *);

static void moxa_shut_down(struct tty_struct *);

/*

 * moxa board interface functions:

 */
@@ -217,7 +217,7 @@ static void MoxaPortLineCtrl(struct moxa_port *, int, int); 
static void MoxaPortFlowCtrl(struct moxa_port *, int, int, int, int, int);

static int MoxaPortLineStatus(struct moxa_port *);

static void MoxaPortFlushData(struct moxa_port *, int);

static int MoxaPortWriteData(struct moxa_port *, const unsigned char *, int);

static int MoxaPortWriteData(struct tty_struct *, const unsigned char *, int);

static int MoxaPortReadData(struct moxa_port *);

static int MoxaPortTxQueue(struct moxa_port *);

static int MoxaPortRxQueue(struct moxa_port *);
@@ -332,6 +332,7 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file, 
		for (i = 0; i < MAX_BOARDS; i++) {

			p = moxa_boards[i].ports;

			for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) {

				struct tty_struct *ttyp;

				memset(&tmp, 0, sizeof(tmp));

				if (!moxa_boards[i].ready)

					goto copy;
@@ -344,10 +345,12 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file, 
				if (status & 4)

					tmp.dcd = 1;



				if (!p->port.tty || !p->port.tty->termios)

				ttyp = tty_port_tty_get(&p->port);

				if (!ttyp || !ttyp->termios)

					tmp.cflag = p->cflag;

				else

					tmp.cflag = p->port.tty->termios->c_cflag;

					tmp.cflag = ttyp->termios->c_cflag;

				tty_kref_put(tty);

copy:

				if (copy_to_user(argm, &tmp, sizeof(tmp))) {

					mutex_unlock(&moxa_openlock);
@@ -880,8 +883,14 @@ static void moxa_board_deinit(struct moxa_board_conf *brd) 


	/* pci hot-un-plug support */

	for (a = 0; a < brd->numPorts; a++)

		if (brd->ports[a].port.flags & ASYNC_INITIALIZED)

			tty_hangup(brd->ports[a].port.tty);

		if (brd->ports[a].port.flags & ASYNC_INITIALIZED) {

			struct tty_struct *tty = tty_port_tty_get(

						&brd->ports[a].port);

			if (tty) {

				tty_hangup(tty);

				tty_kref_put(tty);

			}

		}

	while (1) {

		opened = 0;

		for (a = 0; a < brd->numPorts; a++)
@@ -1096,13 +1105,14 @@ static void __exit moxa_exit(void) 
module_init(moxa_init);

module_exit(moxa_exit);



static void moxa_close_port(struct moxa_port *ch)

static void moxa_close_port(struct tty_struct *tty)

{

	moxa_shut_down(ch);

	struct moxa_port *ch = tty->driver_data;

	moxa_shut_down(tty);

	MoxaPortFlushData(ch, 2);

	ch->port.flags &= ~ASYNC_NORMAL_ACTIVE;

	ch->port.tty->driver_data = NULL;

	ch->port.tty = NULL;

	tty->driver_data = NULL;

	tty_port_tty_set(&ch->port, NULL);

}



static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp,
@@ -1161,7 +1171,7 @@ static int moxa_open(struct tty_struct *tty, struct file *filp) 
	ch = &brd->ports[port % MAX_PORTS_PER_BOARD];

	ch->port.count++;

	tty->driver_data = ch;

	ch->port.tty = tty;

	tty_port_tty_set(&ch->port, tty);

	if (!(ch->port.flags & ASYNC_INITIALIZED)) {

		ch->statusflags = 0;

		moxa_set_tty_param(tty, tty->termios);
@@ -1179,7 +1189,7 @@ static int moxa_open(struct tty_struct *tty, struct file *filp) 
	if (retval) {

		if (ch->port.count) /* 0 means already hung up... */

			if (--ch->port.count == 0)

				moxa_close_port(ch);

				moxa_close_port(tty);

	} else

		ch->port.flags |= ASYNC_NORMAL_ACTIVE;

	mutex_unlock(&moxa_openlock);
@@ -1219,7 +1229,7 @@ static void moxa_close(struct tty_struct *tty, struct file *filp) 
		tty_wait_until_sent(tty, 30 * HZ);	/* 30 seconds timeout */

	}



	moxa_close_port(ch);

	moxa_close_port(tty);

unlock:

	mutex_unlock(&moxa_openlock);

}
@@ -1234,7 +1244,7 @@ static int moxa_write(struct tty_struct *tty, 
		return 0;



	spin_lock_bh(&moxa_lock);

	len = MoxaPortWriteData(ch, buf, count);

	len = MoxaPortWriteData(tty, buf, count);

	spin_unlock_bh(&moxa_lock);



	ch->statusflags |= LOWWAIT;
@@ -1409,7 +1419,7 @@ static void moxa_hangup(struct tty_struct *tty) 
		return;

	}

	ch->port.count = 0;

	moxa_close_port(ch);

	moxa_close_port(tty);

	mutex_unlock(&moxa_openlock);



	wake_up_interruptible(&ch->port.open_wait);
@@ -1417,11 +1427,14 @@ static void moxa_hangup(struct tty_struct *tty) 


static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd)

{

	struct tty_struct *tty;

	dcd = !!dcd;



	if (dcd != p->DCDState && p->port.tty && C_CLOCAL(p->port.tty)) {

		if (!dcd)

			tty_hangup(p->port.tty);

	if (dcd != p->DCDState) {

		tty = tty_port_tty_get(&p->port);

		if (tty && C_CLOCAL(tty) && !dcd)

			tty_hangup(tty);

		tty_kref_put(tty);

	}

	p->DCDState = dcd;

}
@@ -1429,7 +1442,7 @@ static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd) 
static int moxa_poll_port(struct moxa_port *p, unsigned int handle,

		u16 __iomem *ip)

{

	struct tty_struct *tty = p->port.tty;

	struct tty_struct *tty = tty_port_tty_get(&p->port);

	void __iomem *ofsAddr;

	unsigned int inited = p->port.flags & ASYNC_INITIALIZED;

	u16 intr;
@@ -1476,6 +1489,7 @@ static int moxa_poll_port(struct moxa_port *p, unsigned int handle, 
		tty_insert_flip_char(tty, 0, TTY_BREAK);

		tty_schedule_flip(tty);

	}

	tty_kref_put(tty);



	if (intr & IntrLine)

		moxa_new_dcdstate(p, readb(ofsAddr + FlagStat) & DCD_state);
@@ -1560,9 +1574,9 @@ static void moxa_setup_empty_event(struct tty_struct *tty) 
	spin_unlock_bh(&moxa_lock);

}



static void moxa_shut_down(struct moxa_port *ch)

static void moxa_shut_down(struct tty_struct *tty)

{

	struct tty_struct *tp = ch->port.tty;

	struct moxa_port *ch = tty->driver_data;



	if (!(ch->port.flags & ASYNC_INITIALIZED))

		return;
@@ -1572,7 +1586,7 @@ static void moxa_shut_down(struct moxa_port *ch) 
	/*

	 * If we're a modem control device and HUPCL is on, drop RTS & DTR.

	 */

	if (C_HUPCL(tp))

	if (C_HUPCL(tty))

		MoxaPortLineCtrl(ch, 0, 0);



	spin_lock_bh(&moxa_lock);
@@ -1953,9 +1967,10 @@ static int MoxaPortLineStatus(struct moxa_port *port) 
	return val;

}



static int MoxaPortWriteData(struct moxa_port *port,

static int MoxaPortWriteData(struct tty_struct *tty,

		const unsigned char *buffer, int len)

{

	struct moxa_port *port = tty->driver_data;

	void __iomem *baseAddr, *ofsAddr, *ofs;

	unsigned int c, total;

	u16 head, tail, tx_mask, spage, epage;