Re: [PATCH v4 1/8] i2c: Add pointer dereference protection to i2c_match_id()

Kieran Bingham
2015-09-11T09:48:47Z

Hi Lee,

On 11 September 2015 at 10:31, Lee Jones <lee.jones@linaro.org> wrote:
> On Wed, 09 Sep 2015, Kieran Bingham wrote:
>
>> From: Lee Jones <lee.jones@linaro.org>
>>
>> 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 <grant.likely@linaro.org>
>> Signed-off-by: Lee Jones <lee.jones@linaro.org>
>
> SoB?

My apologies, I only added SOB to the patches I had modified ...
I didn't realise it should go on the ones I didn't touch as well.

I'll update and resend.

--
Regards

>
>> ---
>> 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