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: