Re: [dpdk-dev] [PATCH v2] lib/efd: fix to free tail queue entry after use

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 11/23/18 2:30 PM, Maxime Coquelin wrote:
> 
> 
> On 11/14/18 12:17 PM, Hari Kumar Vemula wrote:
>> In rte_efd_create() allocated memory for tail queue entry but
>> not freed.
>> Added freeing the tail queue entry.
>>
>> Fixes: 56b6ef874f80 ("efd: new Elastic Flow Distributor library")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Hari Kumar Vemula <hari.kumarx.vemula@intel.com>
>> Acked-by: Reshma Pattan <reshma.pattan@intel.com>
>>
>> ---
>> v2: Updated commit message.
>> ---
>>
>>   lib/librte_efd/rte_efd.c | 21 +++++++++++++++++++++
>>   1 file changed, 21 insertions(+)
>>
>> diff --git a/lib/librte_efd/rte_efd.c b/lib/librte_efd/rte_efd.c
>> index a780e2fe8..f8c6c447f 100644
>> --- a/lib/librte_efd/rte_efd.c
>> +++ b/lib/librte_efd/rte_efd.c
>> @@ -739,17 +739,38 @@ void
>>   rte_efd_free(struct rte_efd_table *table)
>>   {
>>       uint8_t socket_id;
>> +    struct rte_efd_list *efd_list = NULL;
> 
> NULL init seems useless here.
> 
>> +    struct rte_tailq_entry *te;
>>       if (table == NULL)
>>           return;
>> +    efd_list = RTE_TAILQ_CAST(rte_efd_tailq.head, rte_efd_list);
>> +
>>       for (socket_id = 0; socket_id < RTE_MAX_NUMA_NODES; socket_id++)
>>           rte_free(table->chunks[socket_id]);
>> +    rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);
>> +
>> +    /* find our tailq entry */
>> +    TAILQ_FOREACH(te, efd_list, next) {
>> +        if (te->data == (void *) table)
>> +            break;
>> +    }
>> +
>> +    if (te == NULL) {
>> +        rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
>> +        return;

And in this case, I think there is a leak, as all table stuffs don't get
freed.

>> +    }
>> +
>> +    TAILQ_REMOVE(efd_list, te, next);
>> +    rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
> 
> Wouldn't this be simpler by using TAILQ_FOREACH_SAFE() instead?
> The element could removed from the list and freed within the loop.
> 
>> +
>>       rte_ring_free(table->free_slots);
>>       rte_free(table->offline_chunks);
>>       rte_free(table->keys);
>>       rte_free(table);
>> +    rte_free(te);
>>   }
>>   /**
>>