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=-2.1 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 DFF33C4321A for ; Sat, 29 Jun 2019 07:41:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E086214AF for ; Sat, 29 Jun 2019 07:41:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=web.de header.i=@web.de header.b="Zza18gqE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726852AbfF2HlZ (ORCPT ); Sat, 29 Jun 2019 03:41:25 -0400 Received: from mout.web.de ([212.227.17.11]:41873 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726789AbfF2HlY (ORCPT ); Sat, 29 Jun 2019 03:41:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1561794052; bh=JGm6xjnJ/hvdnhaxOvO5r4QNC/iO6BgDVdE/wPZe9z8=; h=X-UI-Sender-Class:Subject:From:To:Cc:References:Date:In-Reply-To; b=Zza18gqEAaHreow3+DIA3ZoGBENvFOyD50F30lix5aIlZvUynzQvcdLenFcL6Jac8 zwq/GnzVhzwkbw81qDqPXrMJhlRFCCuzXC6F0kIUlJt/jyBVyzNykCEGqM4RVVQIEM rmvig2SExsRER2n1JKN5C2oU20BXuh/kT+eoa+mY= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from [192.168.1.2] ([93.132.176.71]) by smtp.web.de (mrweb102 [213.165.67.124]) with ESMTPSA (Nemesis) id 0M40zO-1iXZyQ09uE-00rYIk; Sat, 29 Jun 2019 09:40:52 +0200 Subject: Re: [v2] coccinelle: semantic code search for missing of_node_put From: Markus Elfring To: Wen Yang , linux-kernel@vger.kernel.org, cocci@systeme.lip6.fr Cc: Yi Wang , Julia Lawall , Gilles Muller , Nicolas Palix , Michal Marek , Masahiro Yamada References: <1561690732-20694-1-git-send-email-wen.yang99@zte.com.cn> <904b9362-cd01-ffc9-600b-0c48848617a0@web.de> Openpgp: preference=signencrypt Autocrypt: addr=Markus.Elfring@web.de; 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Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <904b9362-cd01-ffc9-600b-0c48848617a0@web.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:kQ3P0CsmExYuhpgLOWqOg91cp8lvok84fySGm5yOssSiP5iuL9G zNT+A0uRqecWi4HnKVq5bJr7FwdeDQ+PdYbxbkmeMmkXuvB0sFxcj2PY5lFfBxImN+kULhQ 7mycJX2Re4m9ZE5njSbGGsj4gVyW+vy8DKJnbJxHdWYkHN8c89iUqLGvroHNjA3yL+nNqEs ncIT0w9/T9uf1ZfTWYslg== X-UI-Out-Filterresults: notjunk:1;V03:K0:W7bN9icyko8=:Re3W9TdA834co/YS5gnAs8 y7GK8OUA0U0GbZg2W58IeYCwl1EY9l7RjL+wlioC5T8Ihde5VTQPo5d0gnbpKbT0mDqrhLpIx 7k6tDZO7oq3N7EhIrHIoxaaBTZyBT1PClJrBpOcwyvNkZKuqWrZqNYsrNC9jxOZXKHPd3b/3r 7Fe7TNdSnSlQKLUZdzxGdOtz2ftnWnEgzYm6ahoMBBVPqEFs7Jp1/+dr+ZPb9qz71CTVlIQpH JvSoeD52hP5SCiN/uDJ9imo29lTAnnuBqTPtTsxQt78c5h2fUv7jYpAT9oJn1o0kkWd/J00C9 TQGJx7djBbqBWsj+z9s3QIed1qSrxoYhrmACSK1uHEl4IY3Qpygj6rn/7X5ZPVvm2ofzwpSPM 2Fi4WA2G0LNE8rvr6BdRllwVoDZw9AMEPtqio6V4TCTBDAfRpW6LgaM/flCA8o9HOOK6KkvAR rqCNbgIJpbiLFIZ9uFovaEAHKrDruDvbtTjl0O/5utAIfW8zbon+rSIVlGHpc8ldx/zEoA4Z+ ge4TCjLMIFIlPjofLD5qNaffRf1W2f9R45RMEBmbsp7f4sV8+kLT81LRZhd3EolRq4xPt+yqp SRRLJAByEIG5r5BsTdUajMZ0Qu12o1GbosgqEEn0JlsghsR8uclg1l7UZFbreGC0KJxtxhy0K H5y/e+1dTu+arFXOWCSZoZfjwdmNgjmWj+3Gml/WtHq0K57dLWpMpcASYAsxRLGupTZgZiVnN BC9WUL6R3gqvp/HJ3YlDLFHki+CHhUHAXxME57K78LtZKle3FQDt1P9VkXFNtFj7gyBZaix9i eVUh6rhy/WQMx6C2BXkG2gst9jcCEehNUujUWn+v13FN/p7fTwahvUvep7DLLm/rdn8AxvI10 EAGpCqkijEQXnVUZkUlvI3Y9vrrF4N/1UOy5xtLHmhi+3UTJ3Vdrifculm27mkvoMX9+HKPhf wOoT6MkQwzok4YmW8EgMJGonW/34RLRoFzSFfpawbywE9HCVLjUiEeJ0CGyd1hDCqzavbLYsh FImktHz45FxIr1IpjLoqUj6OBwMD1ltGiWzrYyIDwfImepGnEW4wI/HvB1pBk41IsmfMrr4o9 UVB8EvxCbUkUtfsAa8T9R7Yt3Xl91mhHZFF Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> +if (x =3D=3D NULL || ...) S >> +... when !=3D e =3D (T)x >> + when !=3D true x =3D=3D NULL > > I wonder if this code exclusion specification is really required > after a null pointer was checked before. I would like to add another view for this implementation detail. The when constraint can express a software desire which can be reasonable to some degree. You would like to be sure that a null pointer will not occ= ur after a corresponding check succeeded. * But I feel unsure about the circumstances under which the Coccinelle sof= tware can determine this aspect actually. * I find that it can eventually make sense only after the content of the local variable (which is identified by =E2=80=9Cx=E2=80=9D) was modi= fied. Thus I would find the exclusion of assignments more useful at this place= . Regards, Markus