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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 4253CC43461 for ; Sat, 5 Sep 2020 17:18:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AFF220760 for ; Sat, 5 Sep 2020 17:18:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728421AbgIERS3 (ORCPT ); Sat, 5 Sep 2020 13:18:29 -0400 Received: from mail2-relais-roc.national.inria.fr ([192.134.164.83]:9368 "EHLO mail2-relais-roc.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728042AbgIERSS (ORCPT ); Sat, 5 Sep 2020 13:18:18 -0400 X-IronPort-AV: E=Sophos;i="5.76,359,1592863200"; d="scan'208";a="466225545" Received: from abo-173-121-68.mrs.modulonet.fr (HELO hadrien) ([85.68.121.173]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Sep 2020 19:18:16 +0200 Date: Sat, 5 Sep 2020 19:18:15 +0200 (CEST) From: Julia Lawall X-X-Sender: jll@hadrien To: Denis Efremov cc: cocci@systeme.lip6.fr, linux-kernel@vger.kernel.org, Kees Cook , "Gustavo A . R . Silva" Subject: Re: [PATCH v3] coccinelle: misc: add uninitialized_var.cocci script In-Reply-To: <20200901094812.428896-1-efremov@linux.com> Message-ID: References: <20200811210127.11889-1-efremov@linux.com> <20200901094812.428896-1-efremov@linux.com> User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 1 Sep 2020, Denis Efremov wrote: > uninitialized_var() macro was removed from the sources [1] and > other warning-silencing tricks were deprecated [2]. The purpose of this > cocci script is to prevent new occurrences of uninitialized_var() > open-coded variants. > > [1] commit 63a0895d960a ("compiler: Remove uninitialized_var() macro") > [2] commit 4b19bec97c88 ("docs: deprecated.rst: Add uninitialized_var()") > > Cc: Kees Cook > Cc: Gustavo A. R. Silva > Signed-off-by: Denis Efremov Applied. julia > --- > Changes in v2: > - Documentation cited in the script's description > - kernel.org link added to the diagnostics messages > - "T *var = &var;" pattern removed > - "var =@p var", "var =@p *(&(var))" patterns added > Changes in v3: > - commit's description changed > > .../coccinelle/misc/uninitialized_var.cocci | 51 +++++++++++++++++++ > 1 file changed, 51 insertions(+) > create mode 100644 scripts/coccinelle/misc/uninitialized_var.cocci > > diff --git a/scripts/coccinelle/misc/uninitialized_var.cocci b/scripts/coccinelle/misc/uninitialized_var.cocci > new file mode 100644 > index 000000000000..8fa845cefe11 > --- /dev/null > +++ b/scripts/coccinelle/misc/uninitialized_var.cocci > @@ -0,0 +1,51 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/// > +/// Please, don't reintroduce uninitialized_var(). > +/// From Documentation/process/deprecated.rst: > +/// For any compiler warnings about uninitialized variables, just add > +/// an initializer. Using warning-silencing tricks is dangerous as it > +/// papers over real bugs (or can in the future), and suppresses unrelated > +/// compiler warnings (e.g. "unused variable"). If the compiler thinks it > +/// is uninitialized, either simply initialize the variable or make compiler > +/// changes. Keep in mind that in most cases, if an initialization is > +/// obviously redundant, the compiler's dead-store elimination pass will make > +/// sure there are no needless variable writes. > +/// > +// Confidence: High > +// Copyright: (C) 2020 Denis Efremov ISPRAS > +// Options: --no-includes --include-headers > +// > + > +virtual context > +virtual report > +virtual org > + > +@r@ > +identifier var; > +type T; > +position p; > +@@ > + > +( > +* T var =@p var; > +| > +* T var =@p *(&(var)); > +| > +* var =@p var > +| > +* var =@p *(&(var)) > +) > + > +@script:python depends on report@ > +p << r.p; > +@@ > + > +coccilib.report.print_report(p[0], > + "WARNING this kind of initialization is deprecated (https://www.kernel.org/doc/html/latest/process/deprecated.html#uninitialized-var)") > + > +@script:python depends on org@ > +p << r.p; > +@@ > + > +coccilib.org.print_todo(p[0], > + "WARNING this kind of initialization is deprecated (https://www.kernel.org/doc/html/latest/process/deprecated.html#uninitialized-var)") > -- > 2.26.2 > >