Re: [dpdk-dev] [PATCH v3] app/proc-info: fix port mask parse issue

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 07-Nov-18 6:10 AM, Li Han wrote:
> parse_portmask return type is int,but global variable
> "enabled_port_mask" type is uint32_t.so in proc_info_parse_args
> function,when parse_portmask return -1,"enabled_port_mask" will
> get a huge value and "if (enabled_port_mask == 0)" will never happen.
> 
> Fixes: 22561383ea17 ("app: replace dump_cfg by proc_info")
> Signed-off-by: Li Han <han.li1@zte.com.cn>
> 
> ---
> v3:
> *fix commit meassges issue
> v2:
> *fix typecast issue
> ---
>   app/proc-info/main.c | 9 +++------
>   1 file changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/app/proc-info/main.c b/app/proc-info/main.c
> index c20effa..650d599 100644
> --- a/app/proc-info/main.c
> +++ b/app/proc-info/main.c
> @@ -37,7 +37,7 @@
>   #define MAX_STRING_LEN 256
>   
>   /**< mask of enabled ports */
> -static uint32_t enabled_port_mask;
> +static uint64_t enabled_port_mask;
>   /**< Enable stats. */
>   static uint32_t enable_stats;
>   /**< Enable xstats. */
> @@ -90,7 +90,7 @@
>   /*
>    * Parse the portmask provided at run time.
>    */
> -static int
> +static unsigned long
>   parse_portmask(const char *portmask)
>   {
>   	char *end = NULL;
> @@ -103,12 +103,9 @@
>   	if ((portmask[0] == '\0') || (end == NULL) || (*end != '\0') ||
>   		(errno != 0)) {
>   		printf("%s ERROR parsing the port mask\n", __func__);
> -		return -1;
> +		return 0;
>   	}
>   
> -	if (pm == 0)
> -		return -1;
> -
>   	return pm;
>   
>   }
> 

Hi,

This fix appears wrong. If you're making the value uint64_t, you cannot 
encode errors in the value. So, it's better to leave the return type as 
int, return 0 or -1 on success/error, and store the parsed result in a 
pointer passed to the function instead. Something like this:

static int
parse_portmask(const char *portmask, uint64_t *mask)
{
...
     if (pm == 0)
	return -1;
     *mask = pm;
     return 0;
}

-- 
Thanks,
Anatoly