Re: [patch net-next] devlink: append split port number to the port name

[Jiri Pirko <jiri@resnulli.us>]

Thu, May 27, 2021 at 02:05:56AM CEST, kuba@kernel.org wrote:
>On Wed, 26 May 2021 12:35:08 +0200 Jiri Pirko wrote:
>> From: Jiri Pirko <jiri@nvidia.com>
>> 
>> Instead of doing sprintf twice in case the port is split or not, append
>> the split port suffix in case the port is split.
>> 
>> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
>
>> diff --git a/net/core/devlink.c b/net/core/devlink.c
>> index 06b2b1941dce..c7754c293010 100644
>> --- a/net/core/devlink.c
>> +++ b/net/core/devlink.c
>> @@ -8632,12 +8632,10 @@ static int __devlink_port_phys_port_name_get(struct devlink_port *devlink_port,
>>  	switch (attrs->flavour) {
>>  	case DEVLINK_PORT_FLAVOUR_PHYSICAL:
>>  	case DEVLINK_PORT_FLAVOUR_VIRTUAL:
>> -		if (!attrs->split)
>> -			n = snprintf(name, len, "p%u", attrs->phys.port_number);
>> -		else
>> -			n = snprintf(name, len, "p%us%u",
>> -				     attrs->phys.port_number,
>> -				     attrs->phys.split_subport_number);
>> +		n = snprintf(name, len, "p%u", attrs->phys.port_number);
>
>snprintf() can return n > len, you need to check for this before
>passing len - n as an unsigned argument below.

Correct, will send v2. Thanks!

>
>> +		if (attrs->split)
>> +			n += snprintf(name + n, len - n, "s%u",
>> +				      attrs->phys.split_subport_number);
>>  		break;
>>  	case DEVLINK_PORT_FLAVOUR_CPU:
>>  	case DEVLINK_PORT_FLAVOUR_DSA:
>