From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752709AbbIKJcB (ORCPT ); Fri, 11 Sep 2015 05:32:01 -0400 Received: from mail-wi0-f173.google.com ([209.85.212.173]:33226 "EHLO mail-wi0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752056AbbIKJb6 (ORCPT ); Fri, 11 Sep 2015 05:31:58 -0400 Date: Fri, 11 Sep 2015 10:31:54 +0100 From: Lee Jones To: Kieran Bingham Cc: Wolfram Sang , Samuel Ortiz , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linus.walleij@linaro.org, grant.likely@linaro.org Subject: Re: [PATCH v4 1/8] i2c: Add pointer dereference protection to i2c_match_id() Message-ID: <20150911093154.GQ3260@x1> References: <1441823627-6227-1-git-send-email-kieranbingham@gmail.com> <1441823627-6227-2-git-send-email-kieranbingham@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1441823627-6227-2-git-send-email-kieranbingham@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 09 Sep 2015, Kieran Bingham wrote: > From: Lee Jones > > Here we're providing dereference protection for i2c_match_id(), which > saves us having to do it each time it's called. We're also stripping > out the (now) needless checks in i2c_device_match(). This patch paves > the way for other, similar code trimming. > > Acked-by: Grant Likely > Signed-off-by: Lee Jones SoB? > --- > drivers/i2c/i2c-core.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > index c83e4d1..30d8a77 100644 > --- a/drivers/i2c/i2c-core.c > +++ b/drivers/i2c/i2c-core.c > @@ -450,6 +450,9 @@ static inline int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) > static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, > const struct i2c_client *client) > { > + if (!(id && client)) > + return NULL; > + > while (id->name[0]) { > if (strcmp(client->name, id->name) == 0) > return id; > @@ -463,8 +466,6 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv) > struct i2c_client *client = i2c_verify_client(dev); > struct i2c_driver *driver; > > - if (!client) > - return 0; > > /* Attempt an OF style match */ > if (of_driver_match_device(dev, drv)) > @@ -475,9 +476,10 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv) > return 1; > > driver = to_i2c_driver(drv); > - /* match on an id table if there is one */ > - if (driver->id_table) > - return i2c_match_id(driver->id_table, client) != NULL; > + > + /* Finally an I2C match */ > + if (i2c_match_id(driver->id_table, client)) > + return 1; > > return 0; > } -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog