Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752959AbaFGHbF (ORCPT ); Sat, 7 Jun 2014 03:31:05 -0400 Received: from mail-we0-f182.google.com ([74.125.82.182]:33338 "EHLO mail-we0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752807AbaFGHaS (ORCPT ); Sat, 7 Jun 2014 03:30:18 -0400 From: Grant Likely Subject: Re: [PATCH 1/9] i2c: Add pointer dereference protection to i2c_match_id() To: Lee Jones , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: wsa@the-dreams.de, linus.walleij@linaro.org, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, Lee Jones In-Reply-To: <1402069952-28022-2-git-send-email-lee.jones@linaro.org> References: <1402069952-28022-1-git-send-email-lee.jones@linaro.org> <1402069952-28022-2-git-send-email-lee.jones@linaro.org> Date: Fri, 06 Jun 2014 23:59:35 +0100 Message-Id: <20140606225935.7491DC4206E@trevor.secretlab.ca> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 6 Jun 2014 16:52:24 +0100, Lee Jones wrote: > 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 > --- > 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 7c7f4b8..d3802dc 100644 > --- a/drivers/i2c/i2c-core.c > +++ b/drivers/i2c/i2c-core.c > @@ -82,6 +82,9 @@ void i2c_transfer_trace_unreg(void) > 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; > @@ -95,8 +98,6 @@ 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)) > @@ -107,9 +108,10 @@ 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; Nit: the above 4 lines can now simply be: return (i2c_match_id(driver->id_table, client) != NULL); g. -- 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/