Re: [dpdk-dev] [PATCH v3] examples/qos_meter: fix unchecked return value

["Mrozowicz, SlawomirX" <slawomirx.mrozowicz@intel.com>]

>-----Original Message-----
>From: Dumitrescu, Cristian
>Sent: Tuesday, May 10, 2016 7:42 PM
>To: Mrozowicz, SlawomirX <slawomirx.mrozowicz@intel.com>
>Cc: dev@dpdk.org; Singh, Jasvinder <jasvinder.singh@intel.com>
>Subject: RE: [PATCH v3] examples/qos_meter: fix unchecked return value
>
>
>
>> -----Original Message-----
>> From: Mrozowicz, SlawomirX
>> Sent: Monday, May 9, 2016 9:38 AM
>> To: Dumitrescu, Cristian <cristian.dumitrescu@intel.com>
>> Cc: dev@dpdk.org; Singh, Jasvinder <jasvinder.singh@intel.com>;
>> Mrozowicz, SlawomirX <slawomirx.mrozowicz@intel.com>
>> Subject: [PATCH v3] examples/qos_meter: fix unchecked return value
>>
>> Fix issue reported by Coverity.
>>
>> Coverity ID 30693: Unchecked return value
>> check_return: Calling rte_meter_srtcm_config without checking return
>> value.
>>
>> Fixes: e6541fdec8b2 ("meter: initial import")
>>
>> Signed-off-by: Slawomir Mrozowicz <slawomirx.mrozowicz@intel.com>
>> ---
>>  examples/qos_meter/main.c | 15 ++++++++++-----
>> examples/qos_meter/main.h |  2 +-
>>  2 files changed, 11 insertions(+), 6 deletions(-)
>>
>> diff --git a/examples/qos_meter/main.c b/examples/qos_meter/main.c
>> index b968b00..7c69606 100644
>> --- a/examples/qos_meter/main.c
>> +++ b/examples/qos_meter/main.c
>> @@ -133,14 +133,17 @@ struct rte_meter_trtcm_params
>app_trtcm_params[]
>> = {
>>
>>  FLOW_METER app_flows[APP_FLOWS_MAX];
>>
>> -static void
>> +static int
>>  app_configure_flow_table(void)
>>  {
>>  	uint32_t i, j;
>> +	int ret = 0;
>>
>> -	for (i = 0, j = 0; i < APP_FLOWS_MAX; i ++, j = (j + 1) %
>> RTE_DIM(PARAMS)){
>> -		FUNC_CONFIG(&app_flows[i], &PARAMS[j]);
>> -	}
>> +	for (i = 0, j = 0; i < APP_FLOWS_MAX && ret == 0;
>> +			i ++, j = (j + 1) % RTE_DIM(PARAMS))
>> +		ret = FUNC_CONFIG(&app_flows[i], &PARAMS[j]);
>> +
>> +	return ret;
>>  }
>
>This is only returns the configuration status for the last flow and leaves
>undetected an error for any other flow. Why not check the status for each
>flow and return an error on first occurrence?
>For (...){ret = FUNC_CONFIG(...); if (ret) return ret;}
>

This code check status of the function FUNC_CONFIG for each flow and return an error on first occurrence. Rest of functions FUNC_CONFIG are  not called. See terminate condition of the loop.

>>
>>  static inline void
>> @@ -381,7 +384,9 @@ main(int argc, char **argv)
>>  	rte_eth_promiscuous_enable(port_tx);
>>
>>  	/* App configuration */
>> -	app_configure_flow_table();
>> +	ret = app_configure_flow_table();
>> +	if (ret < 0)
>> +		rte_exit(EXIT_FAILURE, "Invalid configure flow table\n");
>>
>>  	/* Launch per-lcore init on every lcore */
>>  	rte_eal_mp_remote_launch(main_loop, NULL, CALL_MASTER); diff --
>git
>> a/examples/qos_meter/main.h b/examples/qos_meter/main.h index
>> 530bf69..54867dc 100644
>> --- a/examples/qos_meter/main.h
>> +++ b/examples/qos_meter/main.h
>> @@ -51,7 +51,7 @@ enum policer_action
>> policer_table[e_RTE_METER_COLORS][e_RTE_METER_COLORS] =  #if
>APP_MODE
>> == APP_MODE_FWD
>>
>>  #define FUNC_METER(a,b,c,d) color, flow_id=flow_id, pkt_len=pkt_len,
>> time=time -#define FUNC_CONFIG(a,b)
>> +#define FUNC_CONFIG(a, b) 0
>>  #define PARAMS	app_srtcm_params
>>  #define FLOW_METER int
>>
>> --
>> 1.9.1