tty: Fix termios tty window resize race with pty/tty pair

[linux-2.6-omap-h63xx.git] / drivers / char / tty_io.c

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index a27160ba21d7d8cb8eb9636da015075b1bc5b587..daeb8f76697123bf47015e0145e5a15ccfe86940 100644 (file)
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2498,7 +2498,7 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
 /**
  *     tty_do_resize           -       resize event
  *     @tty: tty being resized
- *     @real_tty: real tty (if using a pty/tty pair)
+ *     @real_tty: real tty (not the same as tty if using a pty/tty pair)
  *     @rows: rows (character)
  *     @cols: cols (character)
  *
@@ -2512,7 +2512,8 @@ int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
        struct pid *pgrp, *rpgrp;
        unsigned long flags;
 
-       mutex_lock(&tty->termios_mutex);
+       /* For a PTY we need to lock the tty side */
+       mutex_lock(&real_tty->termios_mutex);
        if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
                goto done;
        /* Get the PID values and reference them so we can
@@ -2533,7 +2534,7 @@ int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
        tty->winsize = *ws;
        real_tty->winsize = *ws;
 done:
-       mutex_unlock(&tty->termios_mutex);
+       mutex_unlock(&real_tty->termios_mutex);
        return 0;
 }