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

["Dumitrescu, Cristian" <cristian.dumitrescu@intel.com>]

> -----Original Message-----
> From: Mrozowicz, SlawomirX
> Sent: Wednesday, May 11, 2016 10:15 AM
> To: Dumitrescu, Cristian <cristian.dumitrescu@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: 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.
> 

Where is the status of FUNC_CONFIG checked exactly? I cannot see any check in your code. I can only see returning the status code for the last call of this function in the for loop. I was expecting a check such as: if (ret) return ret.

> >>
> >>  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