Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753409AbcCLP12 (ORCPT ); Sat, 12 Mar 2016 10:27:28 -0500 Received: from anchovy3.45ru.net.au ([203.30.46.155]:38913 "EHLO anchovy.45ru.net.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752103AbcCLP11 (ORCPT ); Sat, 12 Mar 2016 10:27:27 -0500 X-Greylist: delayed 402 seconds by postgrey-1.27 at vger.kernel.org; Sat, 12 Mar 2016 10:27:27 EST Subject: Re: [PATCH] gpio: pca953x: Fix pca953x_gpio_set_multiple() on 64-bit To: Geert Uytterhoeven , Linus Walleij , Alexandre Courbot References: <1457713887-7748-1-git-send-email-geert+renesas@glider.be> Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org From: Phil Reid Message-ID: <56E433C8.10609@electromag.com.au> Date: Sat, 12 Mar 2016 23:20:40 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1457713887-7748-1-git-send-email-geert+renesas@glider.be> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1841 Lines: 52 On 12/03/2016 12:31 AM, Geert Uytterhoeven wrote: > pca953x_gpio_set_multiple() divides by 4 to convert from longs to bytes, > which assumes a 32-bit platform, and is not correct on 64-bit platforms. > Use "sizeof(...)" instead to fix this. > > Fixes: b4818afeacbd8182 ("gpio: pca953x: Add set_multiple to allow multiple bits to be set in one write.") > Signed-off-by: Geert Uytterhoeven Acked-by: Phil Reid > --- > Untested, found by code inspection. > > This bug was introduced in v4.5-rc1, but unless Linus (the other one ;-) > will make a v4.5-rc8, it's probably too late to get this fixed in v4.5. > --- > drivers/gpio/gpio-pca953x.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c > index 23196c5fc17ceb6b..99b375c959987fe9 100644 > --- a/drivers/gpio/gpio-pca953x.c > +++ b/drivers/gpio/gpio-pca953x.c > @@ -367,9 +367,11 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc, > memcpy(reg_val, chip->reg_output, NBANK(chip)); > mutex_lock(&chip->i2c_lock); > for(bank=0; bank - unsigned bankmask = mask[bank/4] >> ((bank % 4) * 8); > + unsigned bankmask = mask[bank / sizeof(*mask)] >> > + ((bank % sizeof(*mask)) * 8); > if(bankmask) { > - unsigned bankval = bits[bank/4] >> ((bank % 4) * 8); > + unsigned bankval = bits[bank / sizeof(*bits)] >> > + ((bank % sizeof(*bits)) * 8); > reg_val[bank] = (reg_val[bank] & ~bankmask) | bankval; > } > } > -- Regards Phil Reid ElectroMagnetic Imaging Technology Pty Ltd Development of Geophysical Instrumentation & Software www.electromag.com.au 3 The Avenue, Midland WA 6056, AUSTRALIA Ph: +61 8 9250 8100 Fax: +61 8 9250 7100 Email: preid@electromag.com.au