Hi Stanislav, I love your patch! Perhaps something to improve: [auto build test WARNING on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Stanislav-Fomichev/xdp-hints-via-kfuncs/20221122-022956 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master patch link: https://lore.kernel.org/r/20221121182552.2152891-3-sdf%40google.com patch subject: [PATCH bpf-next v2 2/8] bpf: XDP metadata RX kfuncs config: ia64-allyesconfig compiler: ia64-linux-gcc (GCC) 12.1.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/intel-lab-lkp/linux/commit/f402227f5d69dc73c19606ed3fdba8f48267e1ad git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Stanislav-Fomichev/xdp-hints-via-kfuncs/20221122-022956 git checkout f402227f5d69dc73c19606ed3fdba8f48267e1ad # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=ia64 SHELL=/bin/bash net/core/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot All warnings (new ones prefixed by >>): net/core/xdp.c:714:15: warning: no previous prototype for 'bpf_xdp_metadata_rx_timestamp_supported' [-Wmissing-prototypes] 714 | noinline bool bpf_xdp_metadata_rx_timestamp_supported(const struct xdp_md *ctx) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ net/core/xdp.c:719:14: warning: no previous prototype for 'bpf_xdp_metadata_rx_timestamp' [-Wmissing-prototypes] 719 | noinline u64 bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> net/core/xdp.c:724:15: warning: no previous prototype for 'bpf_xdp_metadata_rx_hash_supported' [-Wmissing-prototypes] 724 | noinline bool bpf_xdp_metadata_rx_hash_supported(const struct xdp_md *ctx) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> net/core/xdp.c:729:14: warning: no previous prototype for 'bpf_xdp_metadata_rx_hash' [-Wmissing-prototypes] 729 | noinline u32 bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx) | ^~~~~~~~~~~~~~~~~~~~~~~~ vim +/bpf_xdp_metadata_rx_hash_supported +724 net/core/xdp.c 723 > 724 noinline bool bpf_xdp_metadata_rx_hash_supported(const struct xdp_md *ctx) 725 { 726 return false; 727 } 728 > 729 noinline u32 bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx) 730 { 731 return 0; 732 } 733 -- 0-DAY CI Kernel Test Service https://01.org/lkp