Re: [dpdk-dev] [PATCH] app/testpmd: fix passing negative parameter to strerror

[Phil Yang <Phil.Yang@arm.com>]

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Wei Hu (Xavier)
> Sent: Thursday, June 4, 2020 2:22 PM
> To: dev@dpdk.org
> Cc: xavier.huwei@huawei.com
> Subject: [dpdk-dev] [PATCH] app/testpmd: fix passing negative parameter to
> strerror
> 
> Currently, there are coverity defect warnings as blow:
> Coverity issue:
>   In nic_stats_clear function:
>     CID 290021 (#1 of 1): Argument cannot be negative (NEGATIVE_RETURNS)
>     5. negative_returns: ret is passed to a parameter that cannot be
>        negative.
> 
>     CID 289974 (#1 of 1): Argument cannot be negative (NEGATIVE_RETURNS)
>     6. negative_returns: ret is passed to a parameter that cannot be
>        negative.
> 
>   In nic_xstats_clear function:
>     CID 289985 (#1 of 1): Argument cannot be negative (NEGATIVE_RETURNS)
>     5. negative_returns: ret is passed to a parameter that cannot be
>        negative.
> 
>     CID 289850 (#1 of 1): Argument cannot be negative (NEGATIVE_RETURNS)
>     6. negative_returns: ret is passed to a parameter that cannot be
>        negative.
> 
> This patch fixes them by passing '-ret' to the function strerror() when ret
> is negative.
> 
> Fixes: af75078fece3 ("first public release")

It was the commit da328f7f115a ("ethdev: change xstats reset function to return int") introduced this defect in nic_xstats_clear() function.
Not the "first public release" commit. :)

The patch looks good to me.

Thanks,
Phil

> Fixes: 9eb974221f44 ("app/testpmd: fix statistics after reset")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
> ---
>  app/test-pmd/config.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
> index 5381207..356d0d2 100644
> --- a/app/test-pmd/config.c
> +++ b/app/test-pmd/config.c
> @@ -244,14 +244,14 @@ nic_stats_clear(portid_t port_id)
>  	ret = rte_eth_stats_reset(port_id);
>  	if (ret != 0) {
>  		printf("%s: Error: failed to reset stats (port %u): %s",
> -		       __func__, port_id, strerror(ret));
> +		       __func__, port_id, strerror(-ret));
>  		return;
>  	}
> 
>  	ret = rte_eth_stats_get(port_id, &ports[port_id].stats);
>  	if (ret != 0) {
>  		printf("%s: Error: failed to get stats (port %u): %s",
> -		       __func__, port_id, strerror(ret));
> +		       __func__, port_id, strerror(-ret));
>  		return;
>  	}
>  	printf("\n  NIC statistics for port %d cleared\n", port_id);
> @@ -333,14 +333,14 @@ nic_xstats_clear(portid_t port_id)
>  	ret = rte_eth_xstats_reset(port_id);
>  	if (ret != 0) {
>  		printf("%s: Error: failed to reset xstats (port %u): %s",
> -		       __func__, port_id, strerror(ret));
> +		       __func__, port_id, strerror(-ret));
>  		return;
>  	}
> 
>  	ret = rte_eth_stats_get(port_id, &ports[port_id].stats);
>  	if (ret != 0) {
>  		printf("%s: Error: failed to get stats (port %u): %s",
> -		       __func__, port_id, strerror(ret));
> +		       __func__, port_id, strerror(-ret));
>  		return;
>  	}
>  }
> --
> 2.7.4