From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756921AbZKUWKe (ORCPT ); Sat, 21 Nov 2009 17:10:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756873AbZKUWKd (ORCPT ); Sat, 21 Nov 2009 17:10:33 -0500 Received: from mail02d.mail.t-online.hu ([84.2.42.7]:64188 "EHLO mail02d.mail.t-online.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756875AbZKUWKX (ORCPT ); Sat, 21 Nov 2009 17:10:23 -0500 X-Authuid: nmarci Message-ID: <4B08654E.1050609@freemail.hu> Date: Sat, 21 Nov 2009 23:10:22 +0100 From: =?UTF-8?B?TsOpbWV0aCBNw6FydG9u?= User-Agent: Mozilla/5.0 (X11; U; Linux i686; hu-HU; rv:1.8.1.21) Gecko/20090402 SeaMonkey/1.1.16 MIME-Version: 1.0 To: Jaya Kumar CC: cocci@diku.dk, LKML Subject: [PATCH 4/4] cs5535audio: remove redundant zero fill Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-DCC-mail.t-online.hu-Metrics: mail02d.mail.t-online.hu 32711; Body=3 Fuz1=3 Fuz2=3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Márton Németh The buffer is first zeroed out by memset(). Then strncpy() is used to fill the content. The strncpy() function also pads the string till the end of the specified length, which is redundant. The strncpy() does not ensures that the string will be properly closed with 0. Use strlcpy() instead. The semantic match that finds this kind of pattern is as follows: (http://coccinelle.lip6.fr/) // @@ expression buffer; expression size; expression str; @@ memset(buffer, 0, size); ... - strncpy( + strlcpy( buffer, str, sizeof(buffer) ); @@ expression buffer; expression size; expression str; @@ memset(&buffer, 0, size); ... - strncpy( + strlcpy( &buffer, str, sizeof(buffer)); @@ expression buffer; identifier field; expression size; expression str; @@ memset(buffer, 0, size); ... - strncpy( + strlcpy( buffer->field, str, sizeof(buffer->field) ); @@ expression buffer; identifier field; expression size; expression str; @@ memset(&buffer, 0, size); ... - strncpy( + strlcpy( buffer.field, str, sizeof(buffer.field)); // On strncpy() vs strlcpy() see http://www.gratisoft.us/todd/papers/strlcpy.html . Signed-off-by: Márton Németh --- diff -u -p a/sound/pci/cs5535audio/cs5535audio_olpc.c b/sound/pci/cs5535audio/cs5535audio_olpc.c --- a/sound/pci/cs5535audio/cs5535audio_olpc.c 2009-09-10 00:13:59.000000000 +0200 +++ b/sound/pci/cs5535audio/cs5535audio_olpc.c 2009-11-21 22:18:57.000000000 +0100 @@ -156,13 +156,13 @@ int __devinit olpc_quirks(struct snd_car /* drop the original AD1888 HPF control */ memset(&elem, 0, sizeof(elem)); elem.iface = SNDRV_CTL_ELEM_IFACE_MIXER; - strncpy(elem.name, "High Pass Filter Enable", sizeof(elem.name)); + strlcpy(elem.name, "High Pass Filter Enable", sizeof(elem.name)); snd_ctl_remove_id(card, &elem); /* drop the original V_REFOUT control */ memset(&elem, 0, sizeof(elem)); elem.iface = SNDRV_CTL_ELEM_IFACE_MIXER; - strncpy(elem.name, "V_REFOUT Enable", sizeof(elem.name)); + strlcpy(elem.name, "V_REFOUT Enable", sizeof(elem.name)); snd_ctl_remove_id(card, &elem); /* add the OLPC-specific controls */