Re: [dpdk-dev] [PATCH] examples/l3fwd: fix validation for queue id of config tuple

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2016-03-18 10:35, Reshma Pattan:
> Added validation for queue id of config parameter tuple.
> 
> This validation enforces user to enter queue ids of a port
> from 0 and in sequence.
> 
> This additional validation on queue ids avoids ixgbe crash caused by null
> rxq pointer access inside ixgbe_dev_rx_init.
> 
> Reason for null rxq is, L3fwd application allocates memory only for queues passed by user.
> But rte_eth_dev_start  tries to initialize rx queues in sequence from 0 to nb_rx_queues,
> which is not true and coredump while accessing the unallocated queue .
> 
> Fixes: Commit af75078f

Fixes: af75078fece3 ("first public release")

>  	for (i = 0; i < nb_lcore_params; ++i) {
>  		if (lcore_params[i].port_id == port &&
> -			lcore_params[i].queue_id > queue)
> +			lcore_params[i].queue_id > queue &&

This check is not really useful if queue_id == queue+1

> +			lcore_params[i].queue_id == queue+1)
>  			queue = lcore_params[i].queue_id;
> +		else if (lcore_params[i].port_id == port &&

This line repeats the above check.
You can nest the "if" instead of "else if".

> +				lcore_params[i].queue_id != queue+1)
> +			rte_exit(EXIT_FAILURE, "queue ids of the port %d must be"
> +					" in sequence and must start with 0",
> +					lcore_params[i].port_id);
>  	}