From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: 2.5.x opps stopping serial From: Paul Larson In-Reply-To: <200210110845.24687.tomlins@cam.org> References: <3DA683F4.944DFC11@digeo.com> <200210110845.24687.tomlins@cam.org> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: 15 Oct 2002 15:33:07 -0500 Message-Id: <1034713993.17565.34.camel@plars> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org Return-Path: To: Ed Tomlinson Cc: lkml , linux-mm List-ID: On Fri, 2002-10-11 at 07:45, Ed Tomlinson wrote: > Hi, > > I have been seeing this during shutdown ever since I started using 2.5. Figured > I really should report it... There are three serial ports. One for a serial console, > the second for a backUPS ups, the third for a (real) modem. Dist is debian sid. > > Saving state of known serial devices... Unable to handle kernel NULL pointer dereference at virtual addres Looks like it might be similar to one I saw with smatch recently. There are several places in core.c that check info->tty before dereferencing it, but others that don't. I don't think this will fix the one you are seeing, but if it's easily reproducible you could try doing something similar in uart_block_til_ready. --- linux-2.5/drivers/serial/core.c Wed Oct 9 13:45:11 2002 +++ linux-corefix/drivers/serial/core.c Wed Oct 9 13:50:09 2002 @@ -207,7 +207,7 @@ * Setup the RTS and DTR signals once the * port is open and ready to respond. */ - if (info->tty->termios->c_cflag & CBAUD) + if (info->tty && (info->tty->termios->c_cflag & CBAUD)) uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR); } Thanks, Paul Larson -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/