1 files changed, 33 insertions, 15 deletions

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 1b32da6f6cd..34110719fe0 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -629,6 +629,11 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
 
 	tty_lock(tty);
 
+	if (test_bit(TTY_HUPPED, &tty->flags)) {
+		tty_unlock(tty);
+		return;
+	}
+
 	/* some functions below drop BTM, so we need this bit */
 	set_bit(TTY_HUPPING, &tty->flags);
 
@@ -664,7 +669,6 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
 
 	spin_lock_irq(&tty->ctrl_lock);
 	clear_bit(TTY_THROTTLED, &tty->flags);
-	clear_bit(TTY_PUSH, &tty->flags);
 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 	put_pid(tty->session);
 	put_pid(tty->pgrp);
@@ -850,7 +854,8 @@ void disassociate_ctty(int on_exit)
 			struct pid *tty_pgrp = tty_get_pgrp(tty);
 			if (tty_pgrp) {
 				kill_pgrp(tty_pgrp, SIGHUP, on_exit);
-				kill_pgrp(tty_pgrp, SIGCONT, on_exit);
+				if (!on_exit)
+					kill_pgrp(tty_pgrp, SIGCONT, on_exit);
 				put_pid(tty_pgrp);
 			}
 		}
@@ -873,9 +878,8 @@ void disassociate_ctty(int on_exit)
 	spin_lock_irq(&current->sighand->siglock);
 	put_pid(current->signal->tty_old_pgrp);
 	current->signal->tty_old_pgrp = NULL;
-	spin_unlock_irq(&current->sighand->siglock);
 
-	tty = get_current_tty();
+	tty = tty_kref_get(current->signal->tty);
 	if (tty) {
 		unsigned long flags;
 		spin_lock_irqsave(&tty->ctrl_lock, flags);
@@ -892,6 +896,7 @@ void disassociate_ctty(int on_exit)
 #endif
 	}
 
+	spin_unlock_irq(&current->sighand->siglock);
 	/* Now clear signal->tty under the lock */
 	read_lock(&tasklist_lock);
 	session_clear_tty(task_session(current));
@@ -1266,12 +1271,13 @@ static void pty_line_name(struct tty_driver *driver, int index, char *p)
  *
  *	Locking: None
  */
-static void tty_line_name(struct tty_driver *driver, int index, char *p)
+static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p)
 {
 	if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE)
-		strcpy(p, driver->name);
+		return sprintf(p, "%s", driver->name);
 	else
-		sprintf(p, "%s%d", driver->name, index + driver->name_base);
+		return sprintf(p, "%s%d", driver->name,
+			       index + driver->name_base);
 }
 
 /**
@@ -2081,6 +2087,7 @@ retry_open:
 			filp->f_op = &tty_fops;
 		goto retry_open;
 	}
+	clear_bit(TTY_HUPPED, &tty->flags);
 	tty_unlock(tty);
 
 
@@ -2230,7 +2237,7 @@ static int tiocsti(struct tty_struct *tty, char __user *p)
  *
  *	Copies the kernel idea of the window size into the user buffer.
  *
- *	Locking: tty->termios_rwsem is taken to ensure the winsize data
+ *	Locking: tty->winsize_mutex is taken to ensure the winsize data
  *		is consistent.
  */
 
@@ -2238,9 +2245,9 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
 {
 	int err;
 
-	down_read(&tty->termios_rwsem);
+	mutex_lock(&tty->winsize_mutex);
 	err = copy_to_user(arg, &tty->winsize, sizeof(*arg));
-	up_read(&tty->termios_rwsem);
+	mutex_unlock(&tty->winsize_mutex);
 
 	return err ? -EFAULT: 0;
 }
@@ -2261,7 +2268,7 @@ int tty_do_resize(struct tty_struct *tty, struct winsize *ws)
 	unsigned long flags;
 
 	/* Lock the tty */
-	down_write(&tty->termios_rwsem);
+	mutex_lock(&tty->winsize_mutex);
 	if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
 		goto done;
 	/* Get the PID values and reference them so we can
@@ -2276,7 +2283,7 @@ int tty_do_resize(struct tty_struct *tty, struct winsize *ws)
 
 	tty->winsize = *ws;
 done:
-	up_write(&tty->termios_rwsem);
+	mutex_unlock(&tty->winsize_mutex);
 	return 0;
 }
 EXPORT_SYMBOL(tty_do_resize);
@@ -3017,6 +3024,7 @@ void initialize_tty_struct(struct tty_struct *tty,
 	mutex_init(&tty->legacy_mutex);
 	mutex_init(&tty->throttle_mutex);
 	init_rwsem(&tty->termios_rwsem);
+	mutex_init(&tty->winsize_mutex);
 	init_ldsem(&tty->ldisc_sem);
 	init_waitqueue_head(&tty->write_wait);
 	init_waitqueue_head(&tty->read_wait);
@@ -3538,9 +3546,19 @@ static ssize_t show_cons_active(struct device *dev,
 		if (i >= ARRAY_SIZE(cs))
 			break;
 	}
-	while (i--)
-		count += sprintf(buf + count, "%s%d%c",
-				 cs[i]->name, cs[i]->index, i ? ' ':'\n');
+	while (i--) {
+		int index = cs[i]->index;
+		struct tty_driver *drv = cs[i]->device(cs[i], &index);
+
+		/* don't resolve tty0 as some programs depend on it */
+		if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR))
+			count += tty_line_name(drv, index, buf + count);
+		else
+			count += sprintf(buf + count, "%s%d",
+					 cs[i]->name, cs[i]->index);
+
+		count += sprintf(buf + count, "%c", i ? ' ':'\n');
+	}
 	console_unlock();
 
 	return count;