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=-2.6 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 67516C433E1 for ; Mon, 29 Jun 2020 19:07:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 417B520702 for ; Mon, 29 Jun 2020 19:07:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=web.de header.i=@web.de header.b="OBqLHdtE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730536AbgF2TH2 (ORCPT ); Mon, 29 Jun 2020 15:07:28 -0400 Received: from mout.web.de ([212.227.15.3]:52165 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730566AbgF2THI (ORCPT ); Mon, 29 Jun 2020 15:07:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1593457625; bh=pioBlt+k9nGWRixLbuXdhL4vSY3ibRE8urYPEMcMLig=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=OBqLHdtE1RTar2bsiaZaWgq/6EYTwnn5RQtTlze2QaWdv48jee1h7YJzgtZ9zBf98 VFHC4j1pZkSDRnZ2QNy+/o6n6ShMa9jomfj+EUxpHjEECBuQsB9ilP+dZOk+tpJvEu iSQS77lq3MMNLQImBizVbLxsoW3SRpwp6Zkv+kFQ= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from [192.168.1.2] ([93.131.123.16]) by smtp.web.de (mrweb002 [213.165.67.108]) with ESMTPSA (Nemesis) id 0LoHKz-1jAY8k26Ab-00gF4W; Mon, 29 Jun 2020 18:19:43 +0200 Subject: Re: Searching for initialisation of variables by function calls before null pointer checks To: Chunfeng Yun , Greg Kroah-Hartman , Felipe Balbi , Matthias Brugger , linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Coccinelle Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Colin Ian King References: <1593410434-19406-1-git-send-email-chunfeng.yun@mediatek.com> <1593410434-19406-2-git-send-email-chunfeng.yun@mediatek.com> From: Markus Elfring Autocrypt: addr=Markus.Elfring@web.de; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <1593410434-19406-2-git-send-email-chunfeng.yun@mediatek.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:MvjbbF8fHz31+atifBksu7NbJVe858VtHtK/6+a8RB2HWH7I2/5 /x3sQNu8leNfSxDz6S5bcsx/2Z4QtVMIrtB3828HXtbFXJ1PILSSqnTUmycZgQBvGIeuz9s aZEUCtPMg3y/HViGEUOqNNA0OU5Z6Jekbq3Mcs8APDnc+aVdI71H8okJT3oH2ZMEDXASYJq /OpNfKLL7rR6h9GlJbwtQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:JjwsdSR3taY=:wMZMDpPnrmBGUZVysW0oMu 7E8MM7c+GBWZ39RhcWfhbb59uTpWp94ckpTzZHLEw5Gl3L0paITeL6LvtfWCYBx3sR6G7jl+X JcZzZqGCdiyDeeiiJY6YWsqYUl+asTOe6Vh/HYX3jIZhb0/+UXPioEuNfzWuUC+CzBNvRiNkW nFbRQnGdLMA/ntMezCHDigsYWgkXVphJP8oULrf2KqvFAWZ8P8Dhp37LexEyE0YNGY08U49f2 JxYkCxFAbJgG6aMwJmTiNjd9PXbf6Krah+LbYrB2xl8CvIzN1EYWfPx70zloyc2JJqSCTr+36 ht/kG5+26mb4PH6dzYup/cSg/ykHH0qoVSDR6aNsf5X3ocCn//PA9hdmJBAG8PgT6ObrrM4jg EBhydM2CmQmoeqg08RWPpZFa7CU4t2eRLTOYrJhOK7QdN9cyRS1fJJKtRi3Vw7jBuWUFOC9il x/iRisHbfmawZk05t04AKPQqiRh257I/M0Jv/RpinSrQU62JSxsmEMPX7bwYDOdsZJbYfaJuW rWHZM376J6eIC3vOM8V+NXwVvOczk+ofK1rIhVn+drsJCGACEVdlT2Mww5vXHRxROG5oQLyUv p+ESYQ8hGQ+n4qeOtXTE22ILcMf/1IV7dNszc7zAlEFhLxAzJYIhOfOZ8UUky9k0CrVWBAzBI khUJm7OJ3SVr6NUbelm1YSwdWJ6WsMF4CZxzUAFgi92NVNIUNZPTa58envLcgIbnOmZLpKtXJ 0LHrBASYhG+pi+kN16/HUfpSKGhx/OAqsOiN7znlOwptTkuhnU1BbT5bXOwfiVsSwf2jjw23j Ny/2wbtaKBv+k4IW2vOs6ntCehiqLZrkfzwMbOeCjjsk9rWwha8SD17NN6WNho41pvMCQPAqF zOa9VumaVkYuj4U9VsOhw0qj9NqPJr/pimTVOXZWr3g6d/hMnyBtFDEOYKJjvH0+eqIAgnNWS b7f3ajQlZSQEMeMDQuzxmtDvcur4EXxHbniXhVUBwwW9TPjXPWdNjbqdjIiMW0s/2f0cGMubf D3b+544FchJYBFM0QShKBsW0/qqTIH0H+VIsMIHVzUVV+Ezu21omFhhyivJcUr6RwqfNAyfw9 XaKEUY7/hNvSWF2XtLXTaoIdmK8EFsVsqx5KEQdIM1zeo42LxkfcOqAlgrYH/C7mAO8tu9cRz 6hH3QwWXhydckdRRdvx452yRMYGwiHMIRK9IuTg7OGRgoDEyqFCeqAKIO7XiBFn2KRJrRP94b H+Oi/O0eTp4WGpREp Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Some pointers are dereferenced before successful checks. A source code place can be pointed out in an acceptable time frame for a single file by the following script variant for the semantic patch langu= age. @display@ expression action1, action2; expression* pointer1, pointer2; identifier result1, result2; statement is, es; type t1, t2; @@ t1 result1 =3D <+... * action1(..., pointer1, ...) ...+>; ... when any when !=3D pointer1 t2 result2 =3D <+... * action2(..., pointer2, ...) ...+>; ... when any when !=3D pointer1 when !=3D pointer2 *if (!pointer1 || !pointer2 || ...) is else es elfring@Sonne:~/Projekte/Linux/next-patched> time spatch --profile --no-lo= ops drivers/usb/mtu3/mtu3_gadget.c ~/Projekte/Coccinelle/janitor/show_poin= ter_usage_before_null_check11.cocci =E2=80=A6 @@ -332,14 +332,11 @@ error: static int mtu3_gadget_dequeue(struct usb_ep *ep, struct usb_request *req= ) { - struct mtu3_ep *mep =3D to_mtu3_ep(ep); - struct mtu3_request *mreq =3D to_mtu3_request(req); struct mtu3_request *r; unsigned long flags; int ret =3D 0; struct mtu3 *mtu =3D mep->mtu; - if (!ep || !req || mreq->mep !=3D mep) return -EINVAL; dev_dbg(mtu->dev, "%s : req=3D%p\n", __func__, req); =2D-------------------- profiling result =2D-------------------- Main total : 2.030205 sec 1 count Main.outfiles computation : 1.648542 sec 1 count =E2=80=A6 real 0m2,122s user 0m1,977s sys 0m0,037s I have tried this analysis approach out also for source files from the software =E2=80=9CLinux next-20200626=E2=80=9D. elfring@Sonne:~/Projekte/Linux/next-patched> XX=3D$(date) && spatch --no-l= oops --timeout 12 -j 4 --chunksize 1 -dir ~/Projekte/Linux/next-patched ~/= Projekte/Coccinelle/janitor/show_pointer_usage_before_null_check11.cocci >= ~/Projekte/Bau/Linux/scripts/Coccinelle/null/next/20200626/show_pointer_u= sage_before_null_check11.diff 2> ~/Projekte/Bau/Linux/scripts/Coccinelle/n= ull/next/20200626/show_pointer_usage_before_null_check11-errors.txt; YY=3D= $(date) && echo "$XX | $YY" Mo 29. Jun 13:54:54 CEST 2020 | Mo 29. Jun 17:22:37 CEST 2020 Unfortunately, a lot of =E2=80=9Cexceptional=E2=80=9D data processing resu= lts were logged then. elfring@Sonne:~/Projekte/Bau/Linux/scripts/Coccinelle/null/next/20200626> = grep 'EXN: Coccinelle_modules.Common.Timeout' show_pointer_usage_before_nu= ll_check11-errors.txt | wc -l 454 Will such a test run trigger any further development considerations? Regards, Markus