[dpdk-dev] [PATCH] mempool: check for invalid args on creation

[Andrew Rybchenko]

On 17.07.2018 13:37, Pablo de Lara wrote:
> Currently, a mempool can be created if the number of
> objects is zero or the size of these is zero.
> In these scenarios, rte_mempool_create should return NULL,
> as the mempool created is useless.
>
> Signed-off-by: Pablo de Lara <pablo.de.lara.guarch at intel.com>
> ---
>   lib/librte_mempool/rte_mempool.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
>
> diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
> index 8c8b9f809..8c9573f1a 100644
> --- a/lib/librte_mempool/rte_mempool.c
> +++ b/lib/librte_mempool/rte_mempool.c
> @@ -916,6 +916,18 @@ rte_mempool_create_empty(const char *name, unsigned n, unsigned elt_size,
>   
>   	mempool_list = RTE_TAILQ_CAST(rte_mempool_tailq.head, rte_mempool_list);
>   
> +	/* asked for zero items */
> +	if (n == 0) {
> +		rte_errno = EINVAL;
> +		return NULL;
> +	}

I agree which the check since attempt to populate it will most likely 
fail with -ENOSPC.

> +
> +	/* asked for zero-sized elements */
> +	if (elt_size == 0) {
> +		rte_errno = EINVAL;
> +		return NULL;
> +	}
> +

I'm not sure about this one. I could imagine the case when mempool 
elements are
used just as unique markers. So, I'm not sure that we should restrict 
such usage.

>   	/* asked cache too big */
>   	if (cache_size > RTE_MEMPOOL_CACHE_MAX_SIZE ||
>   	    CALC_CACHE_FLUSHTHRESH(cache_size) > n) {