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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 E6840C43381 for ; Fri, 15 Mar 2019 07:30:10 +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 29AE121871 for ; Fri, 15 Mar 2019 07:30:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 29AE121871 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 x2F7Ts47029910 ; Fri, 15 Mar 2019 08:29:54 +0100 (CET) Received: from systeme.lip6.fr (systeme.lip6.fr [127.0.0.1]) by systeme.lip6.fr (Postfix) with ESMTP id EAF057719; Fri, 15 Mar 2019 08:29:53 +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 EAE58770C for ; Fri, 15 Mar 2019 08:29:52 +0100 (CET) Received: from mail3-relais-sop.national.inria.fr (mail3-relais-sop.national.inria.fr [192.134.164.104]) by isis.lip6.fr (8.15.2/lip6) with ESMTP id x2F7ToPv018664 for ; Fri, 15 Mar 2019 08:29:50 +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="5.58,481,1544482800"; d="scan'208";a="299328918" 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; 15 Mar 2019 08:29:50 +0100 Date: Fri, 15 Mar 2019 08:29:49 +0100 (CET) From: Julia Lawall X-X-Sender: jll@hadrien To: Wen Yang In-Reply-To: <1552616681-17985-1-git-send-email-wen.yang99@zte.com.cn> Message-ID: References: <1552616681-17985-1-git-send-email-wen.yang99@zte.com.cn> 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]); Fri, 15 Mar 2019 08:29:54 +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]); Fri, 15 Mar 2019 08:29:50 +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: wang.yi59@zte.com.cn, michal.lkml@markovi.net, nicolas.palix@imag.fr, linux-kernel@vger.kernel.org, cocci@systeme.lip6.fr Subject: Re: [Cocci] [PATCH] coccinelle: semantic patch for missing of_node_put 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 Fri, 15 Mar 2019, Wen Yang wrote: > Looking for places where there is an of_node_put on some paths > but not on others. This SmPL checks that there is a put of the > same data elsewhere in the function, so perhaps that will > alleviate the concern about puts where they are not needed, > while still making it possible to find the ones that are needed. > > Suggested-by: Julia Lawall > Signed-off-by: Wen Yang > Reviewed-by: Julia Lawall > --- > scripts/coccinelle/free/of_node_put.cocci | 57 +++++++++++++++++++++++++++++++ > 1 file changed, 57 insertions(+) > create mode 100644 scripts/coccinelle/free/of_node_put.cocci > > diff --git a/scripts/coccinelle/free/of_node_put.cocci b/scripts/coccinelle/free/of_node_put.cocci > new file mode 100644 > index 0000000..6a29830 > --- /dev/null > +++ b/scripts/coccinelle/free/of_node_put.cocci > @@ -0,0 +1,57 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/// Find missing of_node_put > +/// > +// Confidence: Moderate > +// Comments: > +// Options: --no-includes --include-headers > + > +virtual report > +virtual org > + > +@r exists@ > +local idexpression struct device_node *x; > +identifier f; > +statement S,S1,S2; > +expression e,e1; > +position p1,p2; > +type T,T1; > +@@ > + > +( > +x = f@p1(...); > +... when != e = (T)x I suggest the following: ( if (x) { ... of_node_put(x) ... } | > +if (x == NULL || ...) S1 > +else S2 > +... when != of_node_put(x) > + when != if (x) { ... of_node_put(x) ... } > + when != e1 = (T1)x > +( > +return x; > +| > +return@p2 ...; > +) ) If the first test is for success of the allocation and may lead to an of_node_put, then you can stop. Perhaps if (x) { ... when forall of_node_put(x) ... } there would be better, to check if there is always a put. This could also be done on the other if (x) > +& > +x = f(...) > +... > +if (<+...x...+>) S > +... > +of_node_put(x); There is actually an opportunity here for more reports. Perhaps we can assume that if the function calls of_node_put on anything, then it is needed on everything. So this could be of_node_put(...). But the downside of that is that the original x = f(...) may now let through things that are not reference counted. So you would want two rules, first this one where the function is f and there is a of_node_put on the result of the function, and another one where you consider a known set of functions, and then allow a subsequent of_node_put on anything. It would take some care to ensure that there is only one report per call site. julia > +) > + > +@script:python depends on report@ > +p1 << r.p1; > +p2 << r.p2; > +@@ > + > +coccilib.report.print_report(p2[0], > + "ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line " > + + p1[0].line > + + ", but without a corresponding object release within this function.") > + > +@script:python depends on org@ > +p1 << r.p1; > +p2 << r.p2; > +@@ > + > +cocci.print_main("acquired a node pointer with refcount incremented", p1) > +cocci.print_secs("needed of_node_put", p2) > -- > 2.9.5 > > _______________________________________________ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci