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 A8E32C43381 for ; Sun, 17 Feb 2019 11:37:41 +0000 (UTC) Received: from isis.lip6.fr (isis.lip6.fr [132.227.60.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0A7E721B69 for ; Sun, 17 Feb 2019 11:37:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0A7E721B69 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lip6.fr Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=cocci-bounces@systeme.lip6.fr Received: from systeme.lip6.fr (systeme.lip6.fr [132.227.104.7]) by isis.lip6.fr (8.15.2/lip6) with ESMTP id x1HBbM9k016693 ; Sun, 17 Feb 2019 12:37:22 +0100 (CET) Received: from systeme.lip6.fr (systeme.lip6.fr [127.0.0.1]) by systeme.lip6.fr (Postfix) with ESMTP id A6EB276F4; Sun, 17 Feb 2019 12:37:22 +0100 (CET) Received: from isis.lip6.fr (isis.lip6.fr [132.227.60.2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by systeme.lip6.fr (Postfix) with ESMTPS id BE7FF76E1 for ; Sun, 17 Feb 2019 12:37:19 +0100 (CET) Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) by isis.lip6.fr (8.15.2/lip6) with ESMTP id x1HBbJGo009812 for ; Sun, 17 Feb 2019 12:37:19 +0100 (CET) X-pt: isis.lip6.fr X-Addr-Warning: ATTENTION - Votre correspondant a fourni une adresse d'enveloppe @lip6.fr, mais ce message ne provient pas de lip6.fr ! postmaster@lip6.fr. X-IronPort-AV: E=Sophos;i="5.58,380,1544482800"; d="scan'208";a="369731283" Received: from abo-58-107-68.mrs.modulonet.fr (HELO hadrien) ([85.68.107.58]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Feb 2019 12:37:18 +0100 Date: Sun, 17 Feb 2019 12:37:18 +0100 (CET) From: Julia Lawall X-X-Sender: jll@hadrien To: Markus Elfring In-Reply-To: <8e7ba7c0-b7fe-a1f0-d28b-0c716ecbcfdb@web.de> Message-ID: References: <8e7ba7c0-b7fe-a1f0-d28b-0c716ecbcfdb@web.de> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 X-Greylist: Sender IP whitelisted, Sender e-mail whitelisted, not delayed by milter-greylist-4.4.3 (isis.lip6.fr [132.227.60.2]); Sun, 17 Feb 2019 12:37:23 +0100 (CET) X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.4.3 (isis.lip6.fr [132.227.60.2]); Sun, 17 Feb 2019 12:37:19 +0100 (CET) X-Scanned-By: MIMEDefang 2.78 on 132.227.60.2 X-Scanned-By: MIMEDefang 2.78 on 132.227.60.2 Cc: kernel-janitors@vger.kernel.org, Michal Marek , Wen Yang , Nicolas Palix , LKML , Coccinelle , Cheng Shengyu , Wen Yang Subject: Re: [Cocci] [PATCH v6] coccinelle: semantic code search for missing put_device() X-BeenThere: cocci@systeme.lip6.fr X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: cocci-bounces@systeme.lip6.fr Errors-To: cocci-bounces@systeme.lip6.fr On Sun, 17 Feb 2019, Markus Elfring wrote: > > +@search exists@ > > +local idexpression id; > > +expression x,e,e1; > > +position p1,p2; > > +type T,T1,T2; > > +@@ > > + > > +id = of_find_device_by_node@p1(x) > > +... when != e = id > > I suggest to increase your software development attention also for > another implementation detail. > Source code analysis triggers challenges for safe data flow handling. > the semantic patch language supports search specifications for > the exclusion of specific assignments. > > Does this SmPL code contain a questionable order for the source > and target metavariables? > Can the following variant be more appropriate? > > + ... when != id = e This is possible, but I think unlikely. > > > > +if (id == NULL || ...) { ... return ...; } > > +... when != put_device(&id->dev) > > + when != platform_device_put(id) > > + when != of_dev_put(id) > > + when != if (id) { ... put_device(&id->dev) ... } > > + when != e1 = (T)id > > Would you like to avoid that the return value from the shown function call > gets overwritten in the variable before it was used once at least > (when a bit of extra C code is tolerated before a null pointer check)? Indeed there should be a put then too, but again, it seems unlikely. julia > > Regards, > Markus > _______________________________________________ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci