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

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 07-Apr-21 5:10 PM, Ferruh Yigit wrote:
> On 4/7/2021 4:25 PM, Hemant Agrawal wrote:
>>
>> 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.
>>
> 
> +1 to verify input for APIs.
> 
> Why not do all, what is the downside of checking all input for control 
> path APIs?
> 

+1

Don't have anything useful to add that hasn't already been said, but 
seems like a nice +1-train going on here, so i thought i'd hop on board :D

-- 
Thanks,
Anatoly