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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 58985C43381 for ; Sat, 16 Feb 2019 08:36:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2BDEC222D0 for ; Sat, 16 Feb 2019 08:36:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731048AbfBPIgv (ORCPT ); Sat, 16 Feb 2019 03:36:51 -0500 Received: from mail3-relais-sop.national.inria.fr ([192.134.164.104]:42195 "EHLO mail3-relais-sop.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730942AbfBPIgv (ORCPT ); Sat, 16 Feb 2019 03:36:51 -0500 X-IronPort-AV: E=Sophos;i="5.58,376,1544482800"; d="scan'208";a="296376495" Received: from abo-58-107-68.mrs.modulonet.fr (HELO hadrien) ([85.68.107.58]) by mail3-relais-sop.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Feb 2019 09:36:49 +0100 Date: Sat, 16 Feb 2019 09:36:48 +0100 (CET) From: Julia Lawall X-X-Sender: jll@hadrien To: wen.yang99@zte.com.cn cc: Markus.Elfring@web.de, julia.lawall@lip6.fr, Gilles.Muller@lip6.fr, nicolas.palix@imag.fr, michal.lkml@markovi.net, wang.yi59@zte.com.cn, yamada.masahiro@socionext.com, yellowriver2010@hotmail.com, cheng.shengyu@zte.com.cn, cocci@systeme.lip6.fr, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [v5] coccinelle: semantic code search for missingput_device() In-Reply-To: <201902161633004137519@zte.com.cn> Message-ID: References: 201902161504357846572@zte.com.cn,10281c5d-8b32-0a02-17ae-20bf86f8dc65@web.de <201902161633004137519@zte.com.cn> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-1482400413-1550306209=:3212" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-1482400413-1550306209=:3212 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT On Sat, 16 Feb 2019, wen.yang99@zte.com.cn wrote: > > > Thanks, We will change it to something like this: > > > In a function, for a local variable obtained by of_find_device_by_node() > > > > How do you think about another wording approach? > > > > 1. Precondition: > > It will be checked where the return value is stored from > > a call of the function “of_find_device_by_node”. > > > > 2. The source code search will be continued with … > > Thanks. > This is more rigorous, we will follow your advice > > > > Thank you, but a local variable is necessary. > > > > Would you like to take additional storage possibilities for a safer > > analysis approach into account? > > > > Is the restriction “local” really sufficient when such a pointer > > could be copied to other variables? > > We may be able to handle this situation: > +id = of_find_device_by_node@p1(x) > ... > + when != e1 = (T)id > + when != e1 = &id->dev > + when != e1 = get_device(&id->dev) This looks good. To be double sure, you can put (T)(&id->dev) in the second case. When you have a chance please send the revised version. As long as I don't see that it is giving many false positives, I will accept it. We don't need perfection. We need more to eliminate the memory leaks. julia > > > > But it's over 80 characters. > > > > Long string literals can be accepted because of error message search concerns > > around a tool like “grep”. > > Thanks. > We will follow your advice > > >> Will any more advanced error diagnostics be eventually developed? > > > > > > Hello, we are just doing the practical work in this field. > > > > Are you aware of additional software design options from computer science > > and existing analysis tools? > > We also use the commercial software klockwork, which will also find errors in the code, > but a lot of false positives. > > Regards, > Wen --8323329-1482400413-1550306209=:3212--