From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754423AbaC3XsR (ORCPT ); Sun, 30 Mar 2014 19:48:17 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:37332 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753371AbaC3Xnx (ORCPT ); Sun, 30 Mar 2014 19:43:53 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Finn Thain" , "Greg Kroah-Hartman" , "Benjamin Herrenschmidt" , "Geert Uytterhoeven" Date: Mon, 31 Mar 2014 00:23:35 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 181/200] TTY: pmac_zilog, check existence of ports in pmz_console_init() In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.56-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Geert Uytterhoeven commit dc1dc2f8a5dd863bf2e79f338fc3ae29e99c683a upstream. When booting a multi-platform m68k kernel on a non-Mac with "console=ttyS0" on the kernel command line, it crashes with: Unable to handle kernel NULL pointer dereference at virtual address (null) Oops: 00000000 PC: [<0013ad28>] __pmz_startup+0x32/0x2a0 ... Call Trace: [<002c5d3e>] pmz_console_setup+0x64/0xe4 The normal tty driver doesn't crash, because init_pmz() checks pmz_ports_count again after calling pmz_probe(). In the serial console initialization path, pmz_console_init() doesn't do this, causing the driver to crash later. Add a check for pmz_ports_count to fix this. Signed-off-by: Geert Uytterhoeven Cc: Finn Thain Cc: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/tty/serial/pmac_zilog.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/tty/serial/pmac_zilog.c +++ b/drivers/tty/serial/pmac_zilog.c @@ -2198,6 +2198,9 @@ static int __init pmz_console_init(void) /* Probe ports */ pmz_probe(); + if (pmz_ports_count == 0) + return -ENODEV; + /* TODO: Autoprobe console based on OF */ /* pmz_console.index = i; */ register_console(&pmz_console);