From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753483Ab3AGCJS (ORCPT ); Sun, 6 Jan 2013 21:09:18 -0500 Received: from proofpoint-cluster.metrocast.net ([65.175.128.136]:51810 "EHLO proofpoint-cluster.metrocast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753311Ab3AGCJP (ORCPT ); Sun, 6 Jan 2013 21:09:15 -0500 References: <1357523523-39707-1-git-send-email-nickolai@csail.mit.edu> User-Agent: K-9 Mail for Android In-Reply-To: <1357523523-39707-1-git-send-email-nickolai@csail.mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH v2] media: cx18, ivtv: eliminate unnecessary array index checks From: Andy Walls Date: Sun, 06 Jan 2013 21:08:39 -0500 To: Nickolai Zeldovich , Mauro Carvalho Chehab CC: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Message-ID: <041715b8-e711-4c63-a123-296c5b674edf@email.android.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.9.8327,1.0.431,0.0.0000 definitions=2013-01-07_01:2013-01-04,2013-01-07,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 ipscore=0 suspectscore=2 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=6.0.2-1211240000 definitions=main-1301060338 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Nickolai Zeldovich wrote: >The idx values passed to cx18_i2c_register() and ivtv_i2c_register() >by cx18_init_subdevs() and ivtv_load_and_init_modules() respectively >are always in-range, based on how the hw_all bitmask is populated. >Previously, the checks were already ineffective because arrays were >being dereferenced using the index before the check. > >Signed-off-by: Nickolai Zeldovich >--- >Thanks to Andy Walls for suggesting that instead of moving the checks >before array dereference, a better fix is to remove the checks >altogether, >since they are superfluous. > > drivers/media/pci/cx18/cx18-i2c.c | 3 --- > drivers/media/pci/ivtv/ivtv-i2c.c | 2 -- > 2 files changed, 5 deletions(-) > >diff --git a/drivers/media/pci/cx18/cx18-i2c.c >b/drivers/media/pci/cx18/cx18-i2c.c >index 4908eb7..ccb1d15 100644 >--- a/drivers/media/pci/cx18/cx18-i2c.c >+++ b/drivers/media/pci/cx18/cx18-i2c.c >@@ -116,9 +116,6 @@ int cx18_i2c_register(struct cx18 *cx, unsigned >idx) > const char *type = hw_devicenames[idx]; > u32 hw = 1 << idx; > >- if (idx >= ARRAY_SIZE(hw_addrs)) >- return -1; >- > if (hw == CX18_HW_TUNER) { > /* special tuner group handling */ > sd = v4l2_i2c_new_subdev(&cx->v4l2_dev, >diff --git a/drivers/media/pci/ivtv/ivtv-i2c.c >b/drivers/media/pci/ivtv/ivtv-i2c.c >index 46e262b..bc984af 100644 >--- a/drivers/media/pci/ivtv/ivtv-i2c.c >+++ b/drivers/media/pci/ivtv/ivtv-i2c.c >@@ -267,8 +267,6 @@ int ivtv_i2c_register(struct ivtv *itv, unsigned >idx) > const char *type = hw_devicenames[idx]; > u32 hw = 1 << idx; > >- if (idx >= ARRAY_SIZE(hw_addrs)) >- return -1; > if (hw == IVTV_HW_TUNER) { > /* special tuner handling */ > sd = v4l2_i2c_new_subdev(&itv->v4l2_dev, adap, type, 0, >-- >1.7.10.4 Acked-by: Andy Walls