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 

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- |
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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 
> ---
>  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(>intf->dev, "Cannot alloc candev\n");
> 

[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 
---
 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(>intf->dev, "Cannot alloc candev\n");
-- 
2.20.1