[PATCH net-next] can: kvaser_usb: Use struct_size() in alloc_candev()

[PATCH net-next] can: kvaser_usb: Use struct_size() in alloc_candev()

[Gustavo A. R. Silva]

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = alloc(sizeof(struct foo) + count * sizeof(void *));

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = alloc(struct_size(instance, entry, count));

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
index c89c7d4900d7..0f1d3e807d63 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
@@ -643,8 +643,7 @@ static int kvaser_usb_init_one(struct kvaser_usb *dev,
 			return err;
 	}
 
-	netdev = alloc_candev(sizeof(*priv) +
-			      dev->max_tx_urbs * sizeof(*priv->tx_contexts),
+	netdev = alloc_candev(struct_size(priv, tx_contexts, dev->max_tx_urbs),
 			      dev->max_tx_urbs);
 	if (!netdev) {
 		dev_err(&dev->intf->dev, "Cannot alloc candev\n");
-- 
2.20.1

Re: [PATCH net-next] can: kvaser_usb: Use struct_size() in alloc_candev()

[Gustavo A. R. Silva]

Hi all,

Friendly ping:

Who can take this?

Thanks
--
Gustavo

On 2/7/19 9:10 PM, Gustavo A. R. Silva wrote:
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
> 
> struct foo {
>     int stuff;
>     void *entry[];
> };
> 
> instance = alloc(sizeof(struct foo) + count * sizeof(void *));
> 
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
> 
> instance = alloc(struct_size(instance, entry, count));
> 
> This code was detected with the help of Coccinelle.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>  drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
> index c89c7d4900d7..0f1d3e807d63 100644
> --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
> +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
> @@ -643,8 +643,7 @@ static int kvaser_usb_init_one(struct kvaser_usb *dev,
>  			return err;
>  	}
>  
> -	netdev = alloc_candev(sizeof(*priv) +
> -			      dev->max_tx_urbs * sizeof(*priv->tx_contexts),
> +	netdev = alloc_candev(struct_size(priv, tx_contexts, dev->max_tx_urbs),
>  			      dev->max_tx_urbs);
>  	if (!netdev) {
>  		dev_err(&dev->intf->dev, "Cannot alloc candev\n");
> 

Re: [PATCH net-next] can: kvaser_usb: Use struct_size() in alloc_candev()

[Gustavo A. R. Silva]

Hi all,

Friendly ping(second one):

Who can take this?

Thanks
--
Gustavo

On 2/25/19 6:48 PM, Gustavo A. R. Silva wrote:
> Hi all,
> 
> Friendly ping:
> 
> Who can take this?
> 
> Thanks
> --
> Gustavo
> 
> On 2/7/19 9:10 PM, Gustavo A. R. Silva wrote:
>> One of the more common cases of allocation size calculations is finding
>> the size of a structure that has a zero-sized array at the end, along
>> with memory for some number of elements for that array. For example:
>>
>> struct foo {
>>     int stuff;
>>     void *entry[];
>> };
>>
>> instance = alloc(sizeof(struct foo) + count * sizeof(void *));
>>
>> Instead of leaving these open-coded and prone to type mistakes, we can
>> now use the new struct_size() helper:
>>
>> instance = alloc(struct_size(instance, entry, count));
>>
>> This code was detected with the help of Coccinelle.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
>> ---
>>  drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
>> index c89c7d4900d7..0f1d3e807d63 100644
>> --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
>> +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
>> @@ -643,8 +643,7 @@ static int kvaser_usb_init_one(struct kvaser_usb *dev,
>>  			return err;
>>  	}
>>  
>> -	netdev = alloc_candev(sizeof(*priv) +
>> -			      dev->max_tx_urbs * sizeof(*priv->tx_contexts),
>> +	netdev = alloc_candev(struct_size(priv, tx_contexts, dev->max_tx_urbs),
>>  			      dev->max_tx_urbs);
>>  	if (!netdev) {
>>  		dev_err(&dev->intf->dev, "Cannot alloc candev\n");
>>

Re: [PATCH net-next] can: kvaser_usb: Use struct_size() in alloc_candev()

[Marc Kleine-Budde]

On 2/8/19 4:10 AM, Gustavo A. R. Silva wrote:
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
> 
> struct foo {
>     int stuff;
>     void *entry[];
> };
> 
> instance = alloc(sizeof(struct foo) + count * sizeof(void *));
> 
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
> 
> instance = alloc(struct_size(instance, entry, count));
> 
> This code was detected with the help of Coccinelle.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Applied to linux-can-next.

Tnx,
Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |

Re: [PATCH net-next] can: kvaser_usb: Use struct_size() in alloc_candev()

[Gustavo A. R. Silva]

Hi Marc,

On 2/26/19 1:52 AM, Marc Kleine-Budde wrote:
> On 2/8/19 4:10 AM, Gustavo A. R. Silva wrote:
>> One of the more common cases of allocation size calculations is finding
>> the size of a structure that has a zero-sized array at the end, along
>> with memory for some number of elements for that array. For example:
>>
>> struct foo {
>>     int stuff;
>>     void *entry[];
>> };
>>
>> instance = alloc(sizeof(struct foo) + count * sizeof(void *));
>>
>> Instead of leaving these open-coded and prone to type mistakes, we can
>> now use the new struct_size() helper:
>>
>> instance = alloc(struct_size(instance, entry, count));
>>
>> This code was detected with the help of Coccinelle.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> 
> Applied to linux-can-next.
> 

I noticed this patch is not in linux-next.

I wonder if you actually applied it to your tree.

Thanks
--
Gustavo