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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 47222ECE58C for ; Fri, 11 Oct 2019 05:16:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D7ED21A4A for ; Fri, 11 Oct 2019 05:16:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=web.de header.i=@web.de header.b="nsU0TBpJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726725AbfJKFQi (ORCPT ); Fri, 11 Oct 2019 01:16:38 -0400 Received: from mout.web.de ([212.227.15.4]:46871 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726099AbfJKFQi (ORCPT ); Fri, 11 Oct 2019 01:16:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1570770956; bh=bdfZdfv0kDFiJjag8bHGUhUdVn4C4VGy8330bt1MT9A=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=nsU0TBpJW+ShOJ5XqcmvvjFyUy3YPVdNAxGWs0rsbaTBqSE9gfVFB+eXtOYXr60nR BkLXSpBY8xJina3TRetCdM5Bj6LIFw35GjCgcUt5pnvUReffnrez6OHgAuvilOiCom e1yf6aRNS2exOhMAlp8EQVXacRHHd/npa1Jy9Pkc= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from [192.168.1.2] ([2.244.164.92]) by smtp.web.de (mrweb001 [213.165.67.108]) with ESMTPSA (Nemesis) id 0MaJc8-1icfbw0kEi-00Jsim; Fri, 11 Oct 2019 07:15:56 +0200 Subject: Re: Searching for missing variable checks To: Rasmus Villemoes , kernel-janitors@vger.kernel.org, Alexander Shishkin , Andrew Morton , Andy Shevchenko , Joe Perches , Kees Cook , Nick Desaulniers , Steven Rostedt , Aditya Pakki , Kangjie Lu , Navid Emamdoost , Stephen McCamant , Coccinelle Cc: LKML References: <75f70e5e-9ece-d6d1-a2c5-2f3ad79b9ccb@web.de> <954c5d70-742f-7b0e-57ad-ea967e93be89@rasmusvillemoes.dk> From: Markus Elfring Autocrypt: addr=Markus.Elfring@web.de; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <954c5d70-742f-7b0e-57ad-ea967e93be89@rasmusvillemoes.dk> Content-Type: text/plain; charset=utf-8 Content-Language: en-US X-Provags-ID: V03:K1:T/VUbhIi6SXgqdz3828YL5FmNXv409l4EkBDA1njed6Ts4T1WRY 1h86oiKchdYB9Q8OkV5VT9oqYRsggXOkXJLGdWo5ativOnLHqXB486YFdX0i+m/gMtUH0B9 urb4LWdfCHfsSiZt2E3EROGQpl2IezgPrrBZ1DYpeP2PjODj5D+YijBeLELtDEEIFki+ewH mYT3pjEdAxjdQ2qTnp+MA== X-UI-Out-Filterresults: notjunk:1;V03:K0:zfP7ojbHTrg=:vep1Nd6qZ0lRDogOPNrJy3 Zscr2NbH2d1CJCAiCzoNi7Zly+nIy2oIvKDQ7jcDvjUEHl/a6YyicJrCdOVx5Cbq8EZqAfrLB vsUSElXYc9vE10r1EBbDmSSpQ+ENSK6ivo4b9HB7r/ub8oQ26h5F/1SSNYeQGHvjbs0YS6GiD 6FP3+Z5ZBMyMEJmpVZ7w0igzm4LOhUaqWG3bJz1xywz0AMOnJBpAZCjNLEWizdIP84+MH6Sqg 46S1fZb9MjjY1qU438rL6/ARnJCkrf1wh9dv3+NnfiIFkPw7U4ljDcvhXJodoDvFkTrMMrCoI CXh3k+I2MeUXrKym/vEGYI7kJArI4r6zsDncxkrUU8l3ZkTYo05orSiSxb2BUeAZWszjbrJlc JG/zKgVAzCHzGMGFoA+nKxFXIItj5JGukQqPbAy39I6x/sTxBGS/mU7CIH/CPtXtDTkbz7xHY 25CGw11S7rHbAurQ5k5yFgsEXkISGOCTZvwrAPODx/JcfJDoWMgjIVDWF8pRO9rT1zWbORr0r tR1ByF01qjbL8jr0NrBjgusmvG3EQm5nuwaztCzNZWYEMJrgbCwJ37e+niiJYZc97nw4FTtBC GDagekI3qTR6MA65gZGZiF+zn34TyRvQHc5XoEMfzBEsrp8g2QVpxVGfUYrcy/AqoDzOssnh6 BONJ52aymyqyHbO/SXS0Qlb56BG6KWLFn4BXy41bRY8kDNVTKR3uqewVEaHinPXuGoOc4C9Rg dal02KTBnjmZyvTsmiL6jCJt+81/wLhZXtgBQr/xFy2l4ZFh+zjiMmQ8YaRnTal5XkjnFzM4V cQhn4+FLB+E0B3XcfF5awn57xhZA5wEYtPx80BL+fM9PKV6Td5eg5m+2EP7v0wLgsPcJggfiJ UCm56y3infpr2IQs+PVGLyVDcjCW2T2jDEPp+x/hAekc2UAp55WbC9Sr3Ag8G0/S25IdAYEUt L9w8Snez1W2gOGVu8Xh/IywBGoDUDRgQijcHGuUG7eYiv2ZGbjkXeJphnYl4nl0oyxFlqi/3R MhetKoiDS0GRUCh+a9VitXGdTvlEI7dUuPHYccRNuzI8i8YVHWyLl9p+wYB7wCu0V7DTejOe+ ZcBRM2bn0TbrR3ybEVCJiJGt+e3EZfPqcLUdOqiG93AJOaq9/NttPdAzqPbEwPSMcOBeXDkBt y6SSqBEOPmyjFQF/queYieKDh/YO0H5bZZuwuZ+S7xC2gL01OplRnc2O1qszEAAMT0BOGp3HI 9N1WxzcCPAtaDGoWzSEsBCbSASZgGfZaGfb+7XMzf40tu++7DJS7/0jc8jeY= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > The problem is the __must_check does not mean that the > return value must be followed by a comparison to NULL and bailing out > (that can't really be checked), it simply ensures the return value is > assigned somewhere or used in an if(). So foo->bar = kstrdup() not > followed by a check of foo->bar won't warn. Higher level source code analysis tools like the semantic patch language (Coccinelle software) can help to find such missing checks. Would you like to point any additional development tools out for this purpose? Regards, Markus