2019-02-08 03:11:46

by Gustavo A. R. Silva

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

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 <[email protected]>
---
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



2019-02-26 00:49:35

by Gustavo A. R. Silva

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

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 <[email protected]>
> ---
> 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");
>

2019-02-26 07:53:09

by Marc Kleine-Budde

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

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 <[email protected]>

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 |

2019-03-28 18:00:02

by Gustavo A. R. Silva

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

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 <[email protected]>
>
> 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

2019-05-01 17:43:11

by Gustavo A. R. Silva

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

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 <[email protected]>
>> ---
>> 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");
>>