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

[Thomas Monjalon <thomas@monjalon.net>]

08/04/2021 03:06, Min Hu (Connor):
> Thanks all,
> Well, Most people who replied support input verification for APIs.
> As the APIs are in control path APIs, so checking all input is OK.
> 
> This is a large project because there are so many APIs and libs in DPDK.
> I will send a set of patches to fix that.
> 
> Thomas, Ferruh, and others, any opinions ?

Let's start with ethdev and we'll see if it looks a good addition,
and if it is well accepted in the community.
Thanks


> 在 2021/4/8 0:26, Burakov, Anatoly 写道:
> > 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
> > 
>