From f6f3c8226b50c2dc33d487a660c0e04766c48c53 Mon Sep 17 00:00:00 2001
From: Jiri Slaby <jslaby@suse.cz>
Date: Fri, 11 Jan 2013 12:06:27 +0100
Subject: [PATCH] pty: return EINVAL for TIOCGPTN for BSD ptys

Commit 1a3bf7456322ff71afd0e7c18e9d5ce4f517f9bc (drivers:tty:fix up
ENOIOCTLCMD error handling) changed the default return value from tty
ioctl to be ENOTTY and not EINVAL. This is appropriate.

But in case of TIOCGPTN for the old BSD ptys glibc started failing
because it expects EINVAL to be returned. Only then it continues to
obtain the pts name the other way around.

So fix this case by explicit return of EINVAL in this case.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Florian Westphal <fw@strlen.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@vger.kernel.org> # 3.7+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/pty.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index be6a373601b78..79ff3a5e925d6 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -441,6 +441,8 @@ static int pty_bsd_ioctl(struct tty_struct *tty,
 		return pty_get_pktmode(tty, (int __user *)arg);
 	case TIOCSIG:    /* Send signal to other side of pty */
 		return pty_signal(tty, (int) arg);
+	case TIOCGPTN: /* TTY returns ENOTTY, but glibc expects EINVAL here */
+		return -EINVAL;
 	}
 	return -ENOIOCTLCMD;
 }
-- 
2.39.5