Re: [dpdk-dev] [PATCH] lib/metrics: fix memory leak

["Power, Ciara" <ciara.power@intel.com>]

Hi Gaurav,


>-----Original Message-----
>From: dev <dev-bounces@dpdk.org> On Behalf Of Honnappa Nagarahalli
>Sent: Tuesday 11 August 2020 22:01
>To: Gaurav Singh <gaurav1086@gmail.com>; dev@dpdk.org
>Cc: nd <nd@arm.com>; Honnappa Nagarahalli
><Honnappa.Nagarahalli@arm.com>; nd <nd@arm.com>
>Subject: Re: [dpdk-dev] [PATCH] lib/metrics: fix memory leak
>
><snip>
>
>>
>> fix memory leak
>>
>> Fixes: c5b7197f66 ("telemetry: move some functions to metrics
>> library")
>>
>> Signed-off-by: Gaurav Singh <gaurav1086@gmail.com>
>> ---
>>  lib/librte_metrics/rte_metrics_telemetry.c | 21 ++++++++++++++++-----
>>  1 file changed, 16 insertions(+), 5 deletions(-)


I think this commit message should be more descriptive, and is missing Cc: stable@dpdk.org


>> diff --git a/lib/librte_metrics/rte_metrics_telemetry.c
>> b/lib/librte_metrics/rte_metrics_telemetry.c
>> index 289ebae0b..7b6d1063c 100644
>> --- a/lib/librte_metrics/rte_metrics_telemetry.c
>> +++ b/lib/librte_metrics/rte_metrics_telemetry.c
>> @@ -41,12 +41,17 @@
>> rte_metrics_tel_reg_port_ethdev_to_metrics(uint16_t
>> port_id)
>>  	}
>>
>>  	xstats_names = malloc(sizeof(*xstats_names) * num_xstats);
>> +	if (xstats_names == NULL) {
>> +		METRICS_LOG_ERR("Failed to malloc memory for
>> xstats_names");
>> +		return -ENOMEM;
>> +	}
>> +
>>  	eth_xstats_names = malloc(sizeof(struct rte_eth_xstat_name)
>>  			* num_xstats);
>> -	if (eth_xstats_names == NULL || xstats_names == NULL) {
>> -		METRICS_LOG_ERR("Failed to malloc memory for
>> xstats_names");
>> -		ret = -ENOMEM;
>> -		goto free_xstats;
>> +	if (eth_xstats_names == NULL) {
>> +		METRICS_LOG_ERR("Failed to malloc memory for
>> eth_xstats_names");
>> +		free(xstats_names);
>> +		return -ENOMEM;
>>  	}

Is there a reason for the above changes? I think they are unrelated to 
the memory leak this patch is fixing.

>>  	if (rte_eth_xstats_get_names(port_id,
>> @@ -167,9 +172,15 @@ rte_metrics_tel_format_port(uint32_t pid, json_t
>> *ports,
>>  	}
>>
>>  	metrics = malloc(sizeof(struct rte_metric_value) * num_metrics);
>> +	if (metrics == NULL) {
>> +		METRICS_LOG_ERR("Cannot allocate memory");
>> +		return -ENOMEM;
>> +	}
>> +
>>  	names = malloc(sizeof(struct rte_metric_name) * num_metrics);
>> -	if (metrics == NULL || names == NULL) {
>> +	if (names == NULL) {
>>  		METRICS_LOG_ERR("Cannot allocate memory");
>> +		free(metrics);
>>  		return -ENOMEM;
>>  	}

This does fix the resource leak, but I do think it can be done in a 
simpler way, as shown in the patch I sent to fix the logged coverity issue
for this: https://patchwork.dpdk.org/patch/78052/
I will remove my patch seeing as this patch is fixing the same thing.
 
Thanks,
Ciara

>> --
>> 2.17.1
>
>Looks good.
>Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>