tty: move the termios object into the tty

This will let us sort out a whole pile of tty related races. The
alternative would be to keep points and refcount the termios objects.
However
1. They are tiny anyway
2. Many devices don't use the stored copies
3. We can remove a pty special case

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 8 insertions, 18 deletions

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index ac96f74573d0..cfd12da81218 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1251,19 +1251,17 @@ int tty_init_termios(struct tty_struct *tty)
 
 	tp = tty->driver->termios[idx];
 	if (tp == NULL) {
-		tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
+		tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
 		if (tp == NULL)
 			return -ENOMEM;
-		memcpy(tp, &tty->driver->init_termios,
-						sizeof(struct ktermios));
+		*tp = tty->driver->init_termios;
 		tty->driver->termios[idx] = tp;
 	}
-	tty->termios = tp;
-	tty->termios_locked = tp + 1;
+	tty->termios = *tp;
 
 	/* Compatibility until drivers always set this */
-	tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
-	tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
+	tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios);
+	tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(tty_init_termios);
@@ -1442,10 +1440,12 @@ void tty_free_termios(struct tty_struct *tty)
 	/* Kill this flag and push into drivers for locking etc */
 	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
 		/* FIXME: Locking on ->termios array */
-		tp = tty->termios;
+		tp = tty->driver->termios[idx];
 		tty->driver->termios[idx] = NULL;
 		kfree(tp);
 	}
+	else
+		*tty->driver->termios[idx] = tty->termios;
 }
 EXPORT_SYMBOL(tty_free_termios);
 
@@ -1575,22 +1575,12 @@ static int tty_release_checks(struct tty_struct *tty, struct tty_struct *o_tty,
 				__func__, idx, tty->name);
 		return -1;
 	}
-	if (tty->termios != tty->driver->termios[idx]) {
-		printk(KERN_DEBUG "%s: driver.termios[%d] not termios for (%s)\n",
-				__func__, idx, tty->name);
-		return -1;
-	}
 	if (tty->driver->other) {
 		if (o_tty != tty->driver->other->ttys[idx]) {
 			printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n",
 					__func__, idx, tty->name);
 			return -1;
 		}
-		if (o_tty->termios != tty->driver->other->termios[idx]) {
-			printk(KERN_DEBUG "%s: other->termios[%d] not o_termios for (%s)\n",
-					__func__, idx, tty->name);
-			return -1;
-		}
 		if (o_tty->link != tty) {
 			printk(KERN_DEBUG "%s: bad pty pointers\n", __func__);
 			return -1;