From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AAD18C433E3 for ; Wed, 19 Aug 2020 16:14:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73FF820888 for ; Wed, 19 Aug 2020 16:14:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597853642; bh=j5FiFlFlH41HiOvE414dXMd/9iwiRcR8XtF1M5BgrW0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=MY1ywyj6LcN2BvHNz/9V218tKJGX3yt5Q6rNymLFwkk3LbaizV2uQzATpqNGZ4Vpu BSl7hOWShZz9Y6fUwmZzjCeWeQCXO06Ha4bjvw0NNhQgdNNgTku2jImD6LzKTDH/aV sXOQDXmHoyYx4F7bnfRqgo+mFCQL3GT9Lq/3rtEE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726899AbgHSQOA convert rfc822-to-8bit (ORCPT ); Wed, 19 Aug 2020 12:14:00 -0400 Received: from mail-ed1-f68.google.com ([209.85.208.68]:35731 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726809AbgHSQN2 (ORCPT ); Wed, 19 Aug 2020 12:13:28 -0400 Received: by mail-ed1-f68.google.com with SMTP id m20so18582647eds.2; Wed, 19 Aug 2020 09:13:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=EkGUFNS7coQmfUryFTJlFWVBsaHRgnCxXeXJMC4zMxQ=; b=GD1A2S4pNkGNOPqMkfM2ONnsyzY5JazvMhkRoUyWPpe8bpeZBbo0d90heSIegYjS75 DF+EHgwOepTOn6aA3nN18AigXBOQFpYzMbcDw350fwaXjPbGm/0NUp20fLl1KY/obrD/ 5Of2airZVDhki5epwX1dti2kMRv//AJaI00npTgI9ILDFBv5Pfbsva8BFu7F2GJkTg9I q4XtbD7Adi/f/y0sVy8ndOAoy8fh27VRrkeYRFguSYAR7JQcYK9R8RUDINbak9Zv2Vtm ivxc6+H0C6c/VBy2hhA9U/pw5IQYtT3CM2eXL00vC/fa/TdcOZMQEuk67gtD+e838Zgn niuQ== X-Gm-Message-State: AOAM5332Br9aqIBJ3YmXZAK7JZa83Icz/zqNahoziLPXuglkOBIS1l9f PtYNazz6wm33YaDxr0NT66M= X-Google-Smtp-Source: ABdhPJwP5263fuZESXpeNUQpfcMaGgY5rsdcXOy8N4cFBHEIzeOdA1e94sgmB2rLn2bzLYJkXY8bgg== X-Received: by 2002:aa7:db59:: with SMTP id n25mr24634678edt.276.1597853605726; Wed, 19 Aug 2020 09:13:25 -0700 (PDT) Received: from kozik-lap ([194.230.155.216]) by smtp.googlemail.com with ESMTPSA id x10sm17726281eds.21.2020.08.19.09.13.24 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Wed, 19 Aug 2020 09:13:25 -0700 (PDT) Date: Wed, 19 Aug 2020 18:13:23 +0200 From: Krzysztof Kozlowski To: Lukasz Stelmach Cc: Kukjin Kim , Andi Shyti , Mark Brown , linux-spi@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, m.szyprowski@samsung.com, b.zolnierkie@samsung.com Subject: Re: [PATCH 6/8] spi: spi-s3c64xx: Check return values Message-ID: <20200819161323.GA8067@kozik-lap> References: <20200819124833.GF18122@kozik-lap> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org On Wed, Aug 19, 2020 at 05:41:43PM +0200, Lukasz Stelmach wrote: > It was <2020-08-19 śro 14:48>, when Krzysztof Kozlowski wrote: > > On Wed, Aug 19, 2020 at 02:32:06PM +0200, Łukasz Stelmach wrote: > >> Signed-off-by: Łukasz Stelmach > >> --- > >> drivers/spi/spi-s3c64xx.c | 12 ++++++++++++ > >> 1 file changed, 12 insertions(+) > > > > Oh, come on, stop fixing the same local issue without fixing bigger > > picture... or at least documenting why bigger picture does not have to be > > fixed and simple 'return' is enough. > > > > That's the third, same fix for the same problem. > > > > https://lore.kernel.org/lkml/20190314064202.14864-1-kjlu@umn.edu/ > > https://lore.kernel.org/lkml/20170207204520.h2eo3yn5kge56lk7@kozik-lap/ > > No wonder. There is a possible NULL dereference below. Now at least we > know something about conditions that led to this. > > Should I drop the entire patch, or just the dmaengine_prep_slave_sg() part? The best would be to really go through the call stack and handle the error properly. This means returning an error code and propagating it further. It is not a trivial change... Best regards, Krzysztof