Hi Alexander, kernel test robot noticed the following build warnings: [auto build test WARNING on net-next/main] url: https://github.com/intel-lab-lkp/linux/commits/Alexander-Mikhalitsyn/sctp-add-bpf_bypass_getsockopt-proto-callback/20230510-211646 base: net-next/main patch link: https://lore.kernel.org/r/20230510131527.1244929-1-aleksandr.mikhalitsyn%40canonical.com patch subject: [PATCH net-next] sctp: add bpf_bypass_getsockopt proto callback config: m68k-defconfig (https://download.01.org/0day-ci/archive/20230510/202305102234.u4T0ut0T-lkp@xxxxxxxxx/config) compiler: m68k-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/8ad9818b4b74026fe549b2aa34ea800ab6c8e66d git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Alexander-Mikhalitsyn/sctp-add-bpf_bypass_getsockopt-proto-callback/20230510-211646 git checkout 8ad9818b4b74026fe549b2aa34ea800ab6c8e66d # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash net/sctp/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Link: https://lore.kernel.org/oe-kbuild-all/202305102234.u4T0ut0T-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> net/sctp/socket.c:8284:6: warning: no previous prototype for 'sctp_bpf_bypass_getsockopt' [-Wmissing-prototypes] 8284 | bool sctp_bpf_bypass_getsockopt(int level, int optname) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ vim +/sctp_bpf_bypass_getsockopt +8284 net/sctp/socket.c 8283 > 8284 bool sctp_bpf_bypass_getsockopt(int level, int optname) 8285 { 8286 /* 8287 * These options do fd_install(), and if BPF_CGROUP_RUN_PROG_GETSOCKOPT 8288 * hook returns an error after success of the original handler 8289 * sctp_getsockopt(...), userspace will receive an error from getsockopt 8290 * syscall and will be not aware that fd was successfully installed into fdtable. 8291 * 8292 * Let's prevent bpf cgroup hook from running on them. 8293 */ 8294 if (level == SOL_SCTP) { 8295 switch (optname) { 8296 case SCTP_SOCKOPT_PEELOFF: 8297 case SCTP_SOCKOPT_PEELOFF_FLAGS: 8298 return true; 8299 default: 8300 return false; 8301 } 8302 } 8303 8304 return false; 8305 } 8306 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests