From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1751367AbdEOKb2 (ORCPT <rfc822;w@1wt.eu>);
        Mon, 15 May 2017 06:31:28 -0400
Received: from mail.linuxfoundation.org ([140.211.169.12]:51004 "EHLO
        mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1750822AbdEOKb1 (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 15 May 2017 06:31:27 -0400
Date: Mon, 15 May 2017 12:31:18 +0200
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Okash Khawaja <okash.khawaja@gmail.com>
Cc: Jiri Slaby <jslaby@suse.com>,
        Samuel Thibault <samuel.thibault@ens-lyon.org>,
        linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org,
        Kirk Reiser <kirk@reisers.ca>, Chris Brannon <chris@the-brannons.com>,
        speakup@linux-speakup.org
Subject: Re: [patch 2/6] tty: export tty_open_by_driver
Message-ID: <20170515103118.GA10885@kroah.com>
References: <20170429195257.630355823@gmail.com>
 <20170429195403.522579504@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20170429195403.522579504@gmail.com>
User-Agent: Mutt/1.8.2 (2017-04-18)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Sat, Apr 29, 2017 at 08:52:59PM +0100, Okash Khawaja wrote:
> This applies on top of the changes already in staging-next branch which allow
> kernel access to TTY dev.
> 
> Signe-doff-by: Okash Khawaja <okash.khawaja@gmail.com>
> Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
> 
> Index: linux-staging/drivers/tty/tty_io.c
> ===================================================================
> --- linux-staging.orig/drivers/tty/tty_io.c
> +++ linux-staging/drivers/tty/tty_io.c
> @@ -1369,7 +1369,10 @@ static struct tty_struct *tty_driver_loo
>  	struct tty_struct *tty;
>  
>  	if (driver->ops->lookup)
> -		tty = driver->ops->lookup(driver, file, idx);
> +		if (!file)
> +			tty = ERR_PTR(-EIO);
> +		else
> +			tty = driver->ops->lookup(driver, file, idx);

Why make this change?  Shouldn't the lookup function allow a NULL file
pointer?  Or is the problem that they do not?

>  	else
>  		tty = driver->ttys[idx];
>  
> @@ -2001,7 +2004,7 @@ static struct tty_driver *tty_lookup_dri
>  		struct tty_driver *console_driver = console_device(index);
>  		if (console_driver) {
>  			driver = tty_driver_kref_get(console_driver);
> -			if (driver) {
> +			if (driver && filp) {

Why change this too?

Your changelog does not explain any of this, please do so.

thanks,

greg k-h