[dpdk-dev] [PATCH] test: fix buffer overflow

[Guo, Jia]

Hi, Alvin

> -----Original Message-----
> From: dev <dev-bounces at dpdk.org> On Behalf Of Zhang,Alvin
> Sent: Wednesday, November 25, 2020 5:46 PM
> To: Liang, Cunming <cunming.liang at intel.com>
> Cc: dev at dpdk.org; Zhang, AlvinX <alvinx.zhang at intel.com>;
> stable at dpdk.org
> Subject: [dpdk-dev] [PATCH] test: fix buffer overflow
> 
> From: Alvin Zhang <alvinx.zhang at intel.com>
> 
> The Tx buffer may overflow when there is more than one port.
> 
> Signed-off-by: Alvin Zhang <alvinx.zhang at intel.com>
> 
> Fixes: 002ade70e933 ("app/test: measure cycles per packet in Rx/Tx")
> Cc: stable at dpdk.org
> ---
>  app/test/test_pmd_perf.c | 18 ++++++++----------
>  1 file changed, 8 insertions(+), 10 deletions(-)
> 
> diff --git a/app/test/test_pmd_perf.c b/app/test/test_pmd_perf.c index
> 4db816a..3a248d5 100644
> --- a/app/test/test_pmd_perf.c
> +++ b/app/test/test_pmd_perf.c
> @@ -606,10 +606,10 @@ enum {
>  static int
>  exec_burst(uint32_t flags, int lcore)
>  {
> -	unsigned i, portid, nb_tx = 0;
> +	unsigned int portid, nb_tx = 0;
>  	struct lcore_conf *conf;
>  	uint32_t pkt_per_port;
> -	int num, idx = 0;
> +	int num, i, idx = 0;
>  	int diff_tsc;
> 
>  	conf = &lcore_conf[lcore];
> @@ -628,16 +628,14 @@ enum {
>  		rte_atomic64_set(&start, 1);
> 
>  	/* start xmit */
> +	i = 0;
>  	while (num) {
>  		nb_tx = RTE_MIN(MAX_PKT_BURST, num);
> -		for (i = 0; i < conf->nb_ports; i++) {
> -			portid = conf->portlist[i];
> -			nb_tx = rte_eth_tx_burst(portid, 0,
> -					 &tx_burst[idx], nb_tx);
> -			idx += nb_tx;
> -			num -= nb_tx;
> -		}
> -
> +		portid = conf->portlist[i];
> +		nb_tx = rte_eth_tx_burst(portid, 0, &tx_burst[idx], nb_tx);
> +		idx += nb_tx;
> +		num -= nb_tx;
> +		i = (i >= conf->nb_ports - 1) ? 0 : (i + 1);

If conf->nb_ports = 1, after the above assign, the i should be 1 and is that your expected?

>  	}
> 
>  	sleep(5);
> --
> 1.8.3.1