pty: simplify resize

We have special case logic for resizing pty/tty pairs. We also have a per
driver resize method so for the pty case we should use it.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 20 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 2a15af65dd11..d33e5ab06177 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2048,7 +2048,6 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
 /**
  *	tty_do_resize		-	resize event
  *	@tty: tty being resized
- *	@real_tty: real tty (not the same as tty if using a pty/tty pair)
  *	@rows: rows (character)
  *	@cols: cols (character)
  *
@@ -2056,41 +2055,34 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
  *	peform a terminal resize correctly
  */
 
-int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
-					struct winsize *ws)
+int tty_do_resize(struct tty_struct *tty, struct winsize *ws)
 {
-	struct pid *pgrp, *rpgrp;
+	struct pid *pgrp;
 	unsigned long flags;
 
-	/* For a PTY we need to lock the tty side */
-	mutex_lock(&real_tty->termios_mutex);
-	if (!memcmp(ws, &real_tty->winsize, sizeof(*ws)))
+	/* Lock the tty */
+	mutex_lock(&tty->termios_mutex);
+	if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
 		goto done;
 	/* Get the PID values and reference them so we can
 	   avoid holding the tty ctrl lock while sending signals */
 	spin_lock_irqsave(&tty->ctrl_lock, flags);
 	pgrp = get_pid(tty->pgrp);
-	rpgrp = get_pid(real_tty->pgrp);
 	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 
 	if (pgrp)
 		kill_pgrp(pgrp, SIGWINCH, 1);
-	if (rpgrp != pgrp && rpgrp)
-		kill_pgrp(rpgrp, SIGWINCH, 1);
-
 	put_pid(pgrp);
-	put_pid(rpgrp);
 
 	tty->winsize = *ws;
-	real_tty->winsize = *ws;
 done:
-	mutex_unlock(&real_tty->termios_mutex);
+	mutex_unlock(&tty->termios_mutex);
 	return 0;
 }
 
 /**
  *	tiocswinsz		-	implement window size set ioctl
- *	@tty; tty
+ *	@tty; tty side of tty
  *	@arg: user buffer for result
  *
  *	Copies the user idea of the window size to the kernel. Traditionally
@@ -2103,17 +2095,16 @@ done:
  *	then calls into the default method.
  */
 
-static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty,
-	struct winsize __user *arg)
+static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg)
 {
 	struct winsize tmp_ws;
 	if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
 		return -EFAULT;
 
 	if (tty->ops->resize)
-		return tty->ops->resize(tty, real_tty, &tmp_ws);
+		return tty->ops->resize(tty, &tmp_ws);
 	else
-		return tty_do_resize(tty, real_tty, &tmp_ws);
+		return tty_do_resize(tty, &tmp_ws);
 }
 
 /**
@@ -2538,7 +2529,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case TIOCGWINSZ:
 		return tiocgwinsz(real_tty, p);
 	case TIOCSWINSZ:
-		return tiocswinsz(tty, real_tty, p);
+		return tiocswinsz(real_tty, p);
 	case TIOCCONS:
 		return real_tty != tty ? -EINVAL : tioccons(file);
 	case FIONBIO: