Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753542AbaF0UNf (ORCPT ); Fri, 27 Jun 2014 16:13:35 -0400 Received: from mail2-relais-roc.national.inria.fr ([192.134.164.83]:23461 "EHLO mail2-relais-roc.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750985AbaF0UNe (ORCPT ); Fri, 27 Jun 2014 16:13:34 -0400 X-IronPort-AV: E=Sophos;i="5.01,562,1400018400"; d="scan'208";a="82590068" Date: Fri, 27 Jun 2014 22:13:32 +0200 (CEST) From: Julia Lawall X-X-Sender: jll@localhost6.localdomain6 To: Fabian Frederick cc: linux-kernel@vger.kernel.org, Julia Lawall , Gilles Muller , Joe Perches , Andrew Morton Subject: Re: [PATCH V2] scripts/coccinelle/free: add NULL test before freeing functions In-Reply-To: <1403899335-3867-1-git-send-email-fabf@skynet.be> Message-ID: References: <1403899335-3867-1-git-send-email-fabf@skynet.be> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Why not make a patch case that removes the test? Since the expression is duplicated in the test and in the argument to kfree it does not seem likely that it will have a side effect. julia On Fri, 27 Jun 2014, Fabian Frederick wrote: > Warns on NULL check before the following functions: > > kfree > usb_free_urb > debugfs_remove > debugfs_remove_recursive > > Cc: Julia Lawall > Cc: Gilles Muller > Cc: Joe Perches > Cc: Andrew Morton > Signed-off-by: Fabian Frederick > --- > V2: > -Add 3 more functions to kfree (suggested by Joe Perches) > -Update warning message to involve code analysis (suggested by Julia Lawall) > > scripts/coccinelle/free/ifnullfree.cocci | 34 ++++++++++++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > create mode 100644 scripts/coccinelle/free/ifnullfree.cocci > > diff --git a/scripts/coccinelle/free/ifnullfree.cocci b/scripts/coccinelle/free/ifnullfree.cocci > new file mode 100644 > index 0000000..626309c > --- /dev/null > +++ b/scripts/coccinelle/free/ifnullfree.cocci > @@ -0,0 +1,34 @@ > +/// NULL check before some freeing functions is not needed. > +/// > +/// Based on checkpatch warning > +/// "kfree(NULL) is safe this check is probably not required" > +/// and kfreeaddr.cocci by Julia Lawall. > +/// > +/// Comments: - > +/// Options: --no-includes --include-headers > + > +virtual org > +virtual report > +virtual context > + > +@r depends on context || report || org @ > +expression E; > +position p; > +@@ > + > +* if (E) > +* \(kfree@p\|debugfs_remove@p\|debugfs_remove_recursive@p\|usb_free_urb\)(E); > + > +@script:python depends on org@ > +p << r.p; > +@@ > + > +cocci.print_main("freeing", p) > + > +@script:python depends on report@ > +p << r.p; > +@@ > + > +msg = "WARNING: NULL check before freeing functions like kfree, debugfs_remove, debugfs_remove_recursive or usb_free_urb is not needed. Maybe consider reorganizing relevant code to avoid passing NULL values." > +coccilib.report.print_report(p[0], msg) > + > -- > 1.8.4.5 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/