Re: [PATCH net-next 2/2] tuntap: XDP transmission

[Jason Wang]

On 2018年01月01日 11:55, Joe Perches wrote:

On Mon, 2018-01-01 at 11:48 +0800, kbuild test robot wrote:

Hi Jason,

I love your patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    
https://github.com/0day-ci/linux/commits/Jason-Wang/XDP-transmission-for-tuntap/20180101-105946
config: i386-randconfig-x072-201800 (attached as .config)
compiler: gcc-7 (Debian 7.2.0-12) 7.2.1 20171025
reproduce:
         # save the attached .config to linux build tree
         make ARCH=i386

All warnings (new ones prefixed by >>):

    drivers//net/tun.c: In function 'tun_xdp_to_ptr':

drivers//net/tun.c:251:9: warning: cast to pointer from integer of different 
size [-Wint-to-pointer-cast]

      return (void *)((unsigned long)ptr | TUN_XDP_FLAG);
             ^
    drivers//net/tun.c: In function 'tun_ptr_to_xdp':
    drivers//net/tun.c:257:9: warning: cast to pointer from integer of 
different size [-Wint-to-pointer-cast]
      return (void *)((unsigned long)ptr & ~TUN_XDP_FLAG);
             ^

vim +251 drivers//net/tun.c

    248 
    249 void *tun_xdp_to_ptr(void *ptr)
    250 {
  > 251              return (void *)((unsigned long)ptr | TUN_XDP_FLAG);

Does TUN_XDP_FLAG really need to be 0x1ULL?
Wouldn't 0x1UL suffice?

0x1UL should be fine.

Thanks