Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 28 Sep 2020 14:17:29 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Ajay Kaher <akaher@vmware.com>
Cc:     b.zolnierkie@samsung.com, daniel.vetter@ffwll.ch,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        torvalds@linux-foundation.org, w@1wt.eu, yuanmingbuaa@gmail.com,
        srivatsab@vmware.com, srivatsa@csail.mit.edu
Subject: Re: [PATCH 4.4 20/46] fbcon: remove soft scrollback code
Message-ID: <20200928121729.GA661457@kroah.com>
References: <20200921162034.253730633@linuxfoundation.org>
 <1601273217-47349-1-git-send-email-akaher@vmware.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1601273217-47349-1-git-send-email-akaher@vmware.com>
Precedence: bulk

On Mon, Sep 28, 2020 at 11:36:57AM +0530, Ajay Kaher wrote:
> > @@ -3378,7 +3054,6 @@ static const struct consw fb_con = {
> >  	.con_font_default	= fbcon_set_def_font,
> >  	.con_font_copy 		= fbcon_copy_font,
> >  	.con_set_palette 	= fbcon_set_palette,
> > -	.con_scrolldelta 	= fbcon_scrolldelta,
> >  	.con_set_origin 	= fbcon_set_origin,
> >  	.con_invert_region 	= fbcon_invert_region,
> >  	.con_screen_pos 	= fbcon_screen_pos,
> 
> If I am not wrong, this change creates crash in v4.4.y.
> As before calling con_scrolldelta, NULL check is missing inside
> console_callback() for v4.4.y, refer:
> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/tty/vt/vt.c?h=linux-4.4.y#n2487
> 
> This NULL check was added in commit 97293de977365fe672daec2523e66ef457104921,
> and this is not merged to v4.4.y

Good catch, will go queue up that portion of that commit to 4.4.y now,
thanks!

greg k-h