From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932676AbcFBUAW (ORCPT ); Thu, 2 Jun 2016 16:00:22 -0400 Received: from mail-yw0-f193.google.com ([209.85.161.193]:32807 "EHLO mail-yw0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932378AbcFBUAS (ORCPT ); Thu, 2 Jun 2016 16:00:18 -0400 From: William Breathitt Gray To: linus.walleij@linaro.org, gnurou@gmail.com Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, William Breathitt Gray Subject: [PATCH] gpio: 104-dio-48e: Fix control port offset computation off-by-one error Date: Thu, 2 Jun 2016 16:00:09 -0400 Message-Id: <1464897609-7389-1-git-send-email-vilhelm.gray@gmail.com> X-Mailer: git-send-email 2.7.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are only two control ports, each controlling three distinct I/O ports. To compute the control port address offset for a respective I/O port, the I/O port address offset should be divided by 3; dividing by 2 may result in not only the wrong address offset but possibly also an out-of-bounds array memory access for a non-existent third control port. Fixes: 1b06d64f7374 ("gpio: Add GPIO support for the ACCES 104-DIO-48E") Signed-off-by: William Breathitt Gray --- drivers/gpio/gpio-104-dio-48e.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c index 1a647c0..fcf7769 100644 --- a/drivers/gpio/gpio-104-dio-48e.c +++ b/drivers/gpio/gpio-104-dio-48e.c @@ -75,7 +75,7 @@ static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned offset) { struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); const unsigned io_port = offset / 8; - const unsigned control_port = io_port / 2; + const unsigned int control_port = io_port / 3; const unsigned control_addr = dio48egpio->base + 3 + control_port*4; unsigned long flags; unsigned control; @@ -115,7 +115,7 @@ static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned offset, { struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); const unsigned io_port = offset / 8; - const unsigned control_port = io_port / 2; + const unsigned int control_port = io_port / 3; const unsigned mask = BIT(offset % 8); const unsigned control_addr = dio48egpio->base + 3 + control_port*4; const unsigned out_port = (io_port > 2) ? io_port + 1 : io_port; -- 2.7.3