From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 1 Dec 2009 15:52:44 +0000 From: Alan Cox To: Pavel Machek Cc: kernel list , linux-bluetooth@vger.kernel.org, Marcel Holtmann Subject: Re: divide by zero in termios when setting bluetooth Message-ID: <20091201155244.0523d9c9@lxorguk.ukuu.org.uk> In-Reply-To: <20091201151315.GC2262@elf.ucw.cz> References: <20091201151315.GC2262@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-ID: On Tue, 1 Dec 2009 16:13:16 +0100 Pavel Machek wrote: > Hi! > > I triggered this by mistake... "W" taint is from the WARN_ON() > before. This ought to fix it serial: Fix crash if the minimum rate of the device is > 9600 baud From: Alan Cox In that situation if the old rate is invalid and the new rate is invalid and the chip cannot do 9600 baud we report zero, which makes all the drivers explode. Instead force the rate based on min/max Signed-off-by: Alan Cox --- drivers/serial/serial_core.c | 17 ++++++++++++----- 1 files changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index 047530b..bd7ec4b 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -385,13 +385,20 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, } /* - * As a last resort, if the quotient is zero, - * default to 9600 bps + * As a last resort, if the range cannot be met then clip to + * the nearest chip supported rate. */ - if (!hung_up) - tty_termios_encode_baud_rate(termios, 9600, 9600); + if (!hung_up) { + if (baud <= min) + tty_termios_encode_baud_rate(termios, + min + 1, min + 1); + else + tty_termios_encode_baud_rate(termios, + max - 1, max - 1); + } } - + /* Should never happen */ + WARN_ON(1); return 0; }