Re: [dpdk-dev] [PATCH] ethdev: fix variable length flow elements support

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 11/4/2021 5:33 AM, Gregory Etelson wrote:
> Hello Ferruh,
> 
>>>    lib/ethdev/rte_flow.c | 6 ++++--
>>>    1 file changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/lib/ethdev/rte_flow.c
>> b/lib/ethdev/rte_flow.c
>>> index d268784532..a93f68abbc 100644
>>> --- a/lib/ethdev/rte_flow.c
>>> +++ b/lib/ethdev/rte_flow.c
>>> @@ -54,11 +54,13 @@
>> rte_flow_conv_copy(void *buf, const void *data,
>> const size_t size,
>>>        /**
>>>         * Allow PMD private flow item
>>>         */
>>> -     size_t sz = type >= 0 ? desc[type].size :
>> sizeof(void *);
>>> +     bool rte_type = type >= 0;
>>> +
>>> +     size_t sz = rte_type ? desc[type].size :
>> sizeof(void *);
>>>        if (buf == NULL || data == NULL)
>>>                return 0;
>>>        rte_memcpy(buf, data, (size > sz ? sz :
>> size));
>>> -     if (desc[type].desc_fn)
>>
>> Was this (possible) negative array index
>> intentional, or are you fixing it?
>>
> 
> Negative type values assigned to PMD private items and actions.
> RTE allows private PMD types in flow rules since
> 5d1bff8fe2 ethdev: allow negative values in flow rule types
> We construct flow rules with private PMD types
> to implement tunnel offload.
> However, negative type must not be used as index in
> rte_flow_desc_item[] and rte_flow_desc_action[] arrays.
> 

That is what I assumed, but wasn't clear from commit log, commit log
reads as it is updating an intended usage.

>>> +     if (rte_type && desc[type].desc_fn)
>>>                sz += desc[type].desc_fn(size > 0 ? buf
>> : NULL, data);
>>>        return sz;
>>>    }
>>>
>