On 12/14/2018 09:11 PM, Andrew Lunn wrote:
> On Fri, Dec 14, 2018 at 02:30:35PM +0100, Marek Vasut wrote:
>> On 12/14/2018 10:05 AM, Andrew Lunn wrote:
>>>> +static struct sk_buff *ksz_common_xmit(struct sk_buff *skb,
>>>> + struct net_device *dev, int len)
>>>> {
>>>> - struct dsa_port *dp = dsa_slave_to_port(dev);
>>>> struct sk_buff *nskb;
>>>> int padlen;
>>>> - u8 *tag;
>>>>
>>>> padlen = (skb->len >= ETH_ZLEN) ? 0 : ETH_ZLEN - skb->len;
>>>>
>>>> - if (skb_tailroom(skb) >= padlen + KSZ_INGRESS_TAG_LEN) {
>>>> + if (skb_tailroom(skb) >= padlen + len) {
>>>> /* Let dsa_slave_xmit() free skb */
>>>> if (__skb_put_padto(skb, skb->len + padlen, false))
>>>> return NULL;
>>>
>>> Hi Marek
>>
>> Hi,
>>
>>> This can return NULL.
>>>
>>>> +static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
>>>> + struct net_device *dev)
>>>> +{
>>>> + struct dsa_port *dp = dsa_slave_to_port(dev);
>>>> + struct sk_buff *nskb;
>>>> + u16 *tag;
>>>> + u8 *addr;
>>>> +
>>>> + nskb = ksz_common_xmit(skb, dev, KSZ9477_INGRESS_TAG_LEN);
>>>
>>> So here you need to check for NULL
>>
>> What do we do if the xmit returns NULL ?
>
> Return NULL to the caller. There are comments which explain this:
Ahh ... right, of course.
> static netdev_tx_t dsa_slave_xmit(struct sk_buff *skb, struct net_device *dev)
> {
> [snip]
> /* Transmit function may have to reallocate the original SKB,
> * in which case it must have freed it. Only free it here on error.
> */
> nskb = p->xmit(skb, dev);
> if (!nskb) {
> kfree_skb(skb);
> return NETDEV_TX_OK;
> }
>
> Andrew
>
--
Best regards,
Marek Vasut
