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

From: Gustavo A. R. Silva
Date: Wed May 01 2019 - 13:42:26 EST


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@xxxxxxxxxxxxxx>
>> ---
>> 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");
>>