Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757335Ab3FKXDN (ORCPT ); Tue, 11 Jun 2013 19:03:13 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:51942 "EHLO mail-pb0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755364Ab3FKXDL (ORCPT ); Tue, 11 Jun 2013 19:03:11 -0400 From: =?UTF-8?q?St=C3=A9phane=20Marchesin?= To: linux-kernel@vger.kernel.org Cc: gregkh@linuxfoundation.org, jslaby@suse.cz, olof@lixom.net, =?UTF-8?q?St=C3=A9phane=20Marchesin?= Subject: [PATCH] drivers/tty: Don't hangup shared ttys Date: Tue, 11 Jun 2013 16:03:07 -0700 Message-Id: <1370991787-24141-1-git-send-email-marcheu@chromium.org> X-Mailer: git-send-email 1.8.3 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1411 Lines: 39 When quickly restarting X servers, we can run into a situation where one X server quits while another one starts on the same tty. For a while, two X servers share the tty, and when the old X server eventually quits, the tty layer hangs up the tty, which among other things stubs out the tty's ioctl functions. Later on, the new X server (which shares the tty functions) tries to call some ioctls on the tty and fails because they have been replaced with the hungup versions. This in turn causes the new X server to abort. This patch checks the tty->count to make sure we're the last consumer before hanging up a tty. Signed-off-by: Stéphane Marchesin --- drivers/tty/tty_io.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 6464029..62a0f02 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -619,6 +619,9 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session) if (!tty) return; + /* Don't hangup if there are other users */ + if (tty->count > 1) + return; spin_lock(&redirect_lock); if (redirect && file_tty(redirect) == tty) { -- 1.8.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/