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

Message ID 1441823627-6227-2-git-send-email-kieranbingham@gmail.com
State New
Headers show

Commit Message

Kieran Bingham Sept. 9, 2015, 6:33 p.m.
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>
---
 drivers/i2c/i2c-core.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

Comments

Lee Jones Sept. 11, 2015, 9:31 a.m. | #1
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?

> ---
>  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;
>  }
Kieran Bingham Sept. 11, 2015, 9:48 a.m. | #2
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
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch hide | download patch | download mbox

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;
 }