From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935444AbcKKA6n (ORCPT ); Thu, 10 Nov 2016 19:58:43 -0500 Received: from www3345.sakura.ne.jp ([49.212.235.55]:25479 "EHLO www3345.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932614AbcKKA6l (ORCPT ); Thu, 10 Nov 2016 19:58:41 -0500 Message-ID: <582517B3.5010407@jinso.co.jp> Date: Fri, 11 Nov 2016 09:58:27 +0900 From: Hiep Cao Minh User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Arnd Bergmann CC: Mark Brown , Chris Brandt , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] spi: rspi: avoid uninitialized variable access References: <20161108134624.1905209-1-arnd@arndb.de> <58243D24.5080302@jinso.co.jp> <5755979.RXybIODAnf@wuerfel> In-Reply-To: <5755979.RXybIODAnf@wuerfel> 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 Hi Arnd, On 11/10/2016 07:51 PM, Arnd Bergmann wrote: > On Thursday, November 10, 2016 6:25:56 PM CET Hiep Cao Minh wrote: >> Hi Arnd, >> >> Thanks for your fixed patch. >> >> On 11/08/2016 10:46 PM, Arnd Bergmann wrote: >>> The newly introduced rspi_pio_transfer_in_or_our() function must >>> take either a valid 'rx' or 'tx' pointer, and has undefined behavior >>> if both are NULL, as found by 'gcc -Wmaybe-unintialized': >>> >>> drivers/spi/spi-rspi.c: In function 'rspi_pio_transfer_in_or_our': >>> drivers/spi/spi-rspi.c:558:5: error: 'len' may be used uninitialized in this function [-Werror=maybe-uninitialized] >> Could you tell me what kind of GCC are you using? >> I'd like to reproduce it on my environment, too. >> I am using the Linaro's gcc of >> "gcc-linaro-arm-linux-gnueabihf-4.8-2014.04_linux". >> But there is no error message like this on my environment. > The warning is currently disabled in mainline Linux, but I'm trying to > address this and hope to still get a revert of 6e8d666e9253 ("Disable > "maybe-uninitialized" warning globally") into v4.9. > > You can build with "make EXTRA_CFLAGS=-Wmaybe-uninitialized" in > the meantime. Thanks, I used your command and found the warning. Best regards, Hiep Jinzai Solution Inc,