Re: [dpdk-dev] Questions about API with no parameter check

[Hemant Agrawal <hemant.agrawal@oss.nxp.com>]

On 4/7/2021 8:10 PM, Ajit Khaparde wrote:
> On Wed, Apr 7, 2021 at 6:20 AM Jerin Jacob <jerinjacobk@gmail.com> wrote:
>> On Wed, Apr 7, 2021 at 5:23 PM Ananyev, Konstantin
>> <konstantin.ananyev@intel.com> wrote:
>>>
>>>
>>>> 07/04/2021 13:28, Min Hu (Connor):
>>>>> Hi, all,
>>>>>      Many APIs in DPDK does not check if the pointer parameter is
>>>>> NULL or not. For example, in 'rte_ethdev.c':
>>>>> int
>>>>> rte_eth_rx_queue_setup(uint16_t port_id, uint16_t rx_queue_id,
>>>>>                     uint16_t nb_rx_desc, unsigned int socket_id,
>>>>>                     const struct rte_eth_rxconf *rx_conf,
>>>>>                     struct rte_mempool *mp)
>>>>>
>>>>> int
>>>>> rte_eth_link_get(uint16_t port_id, struct rte_eth_link *eth_link)
>>>>>
>>>>> int
>>>>> rte_eth_stats_get(uint16_t port_id, struct rte_eth_stats *stats)
>>>>>
>>>>> int
>>>>> rte_eth_dev_info_get(uint16_t port_id, struct rte_eth_dev_info *dev_info)
>>>>>
>>>>> As these APIs could be used by any APPs, if the APP give NULL as
>>>>> the pointer parameter, segmetation default will occur.
>>>>>
>>>>> So, my question is, should we add check in the API? like that,
>>>>> int rte_eth_stats_get(uint16_t port_id, struct rte_eth_stats *stats)
>>>>> {
>>>>>      if (stats == NULL)
>>>>>              return -EINVAL;
>>>>>      ...
>>>>> }
>>>>>
>>>>> Or, that is redundant, the parameter correctness should be guaranteed by
>>>>> the APP?
>>>>>
>>>>> What's your opinion? Hope for your reply.
>>>> I remember it has been discussed in the past (many years ago),
>>>> and the opinion was to not clutter the code for something that
>>>> is a basic fault from the app.
>>>>
>>>> I don't have a strong opinion.
>>>> What is your opinion? Others?
>>> As I can see these are control path functions.
>>> So some extra formal parameters check wouldn't hurt.
>>> +1 from me to add them.
>> +1 to add more sanity checks in control path APIs
> +1
> But are we going to check all parameters?

+1

It may be better to limit the number of checks.

>>
>>> Konstantin
>>>
>>>