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Commit 6054c16e authored by Peter Hurley's avatar Peter Hurley Committed by Greg Kroah-Hartman
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tty: Use spin_lock_irq() for ctrl_lock when interrupts enabled 



Interrupts are enabled in the n_tty_read() loop, ioctl(TIOCPKT)
and pty driver flush_buffer() routine; no need to save and restore
local interrupt state.

Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Reviewed-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4d8c1dff

drivers/tty/n_tty.c

+2 −3
Original line number Diff line number Diff line
@@ -2128,7 +2128,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, 
	int minimum, time;

	ssize_t retval = 0;

	long timeout;

	unsigned long flags;

	int packet;



	c = job_control(tty, file);
@@ -2174,10 +2173,10 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, 
			unsigned char cs;

			if (b != buf)

				break;

			spin_lock_irqsave(&tty->link->ctrl_lock, flags);

			spin_lock_irq(&tty->link->ctrl_lock);

			cs = tty->link->ctrl_status;

			tty->link->ctrl_status = 0;

			spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);

			spin_unlock_irq(&tty->link->ctrl_lock);

			if (tty_put_user(tty, cs, b++)) {

				retval = -EFAULT;

				b--;

drivers/tty/pty.c

+4 −6
Original line number Diff line number Diff line
@@ -178,13 +178,12 @@ static int pty_get_lock(struct tty_struct *tty, int __user *arg) 
/* Set the packet mode on a pty */

static int pty_set_pktmode(struct tty_struct *tty, int __user *arg)

{

	unsigned long flags;

	int pktmode;



	if (get_user(pktmode, arg))

		return -EFAULT;



	spin_lock_irqsave(&tty->ctrl_lock, flags);

	spin_lock_irq(&tty->ctrl_lock);

	if (pktmode) {

		if (!tty->packet) {

			tty->packet = 1;
@@ -192,7 +191,7 @@ static int pty_set_pktmode(struct tty_struct *tty, int __user *arg) 
		}

	} else

		tty->packet = 0;

	spin_unlock_irqrestore(&tty->ctrl_lock, flags);

	spin_unlock_irq(&tty->ctrl_lock);



	return 0;

}
@@ -221,16 +220,15 @@ static int pty_signal(struct tty_struct *tty, int sig) 
static void pty_flush_buffer(struct tty_struct *tty)

{

	struct tty_struct *to = tty->link;

	unsigned long flags;



	if (!to)

		return;

	/* tty_buffer_flush(to); FIXME */

	if (to->packet) {

		spin_lock_irqsave(&tty->ctrl_lock, flags);

		spin_lock_irq(&tty->ctrl_lock);

		tty->ctrl_status |= TIOCPKT_FLUSHWRITE;

		wake_up_interruptible(&to->read_wait);

		spin_unlock_irqrestore(&tty->ctrl_lock, flags);

		spin_unlock_irq(&tty->ctrl_lock);

	}

}