On Sat, Jul 20, 2024 at 7:45 AM kernel test robot <lkp@xxxxxxxxx> wrote: > > Hi Martin, > > kernel test robot noticed the following build warnings: > > [auto build test WARNING on bpf-next/master] > > url: https://github.com/intel-lab-lkp/linux/commits/Martin-KaFai-Lau/bpf-Check-unsupported-ops-from-the-bpf_struct_ops-s-cfi_stubs/20240720-144313 > base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master > patch link: https://lore.kernel.org/r/20240720062233.2319723-2-martin.lau%40linux.dev > patch subject: [PATCH bpf-next 1/3] bpf: Check unsupported ops from the bpf_struct_ops's cfi_stubs > config: i386-randconfig-001-20240720 (https://download.01.org/0day-ci/archive/20240720/202407202244.HvnUVyjM-lkp@xxxxxxxxx/config) > compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0 > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240720/202407202244.HvnUVyjM-lkp@xxxxxxxxx/reproduce) > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > | Reported-by: kernel test robot <lkp@xxxxxxxxx> > | Closes: https://lore.kernel.org/oe-kbuild-all/202407202244.HvnUVyjM-lkp@xxxxxxxxx/ > > All warnings (new ones prefixed by >>): > > kernel/bpf/bpf_struct_ops.c: In function 'bpf_struct_ops_supported': > >> kernel/bpf/bpf_struct_ops.c:1045:48: warning: dereferencing 'void *' pointer > void *func_ptr = *(void **)(&st_ops->cfi_stubs[moff]); > ^ > > > vim +1045 kernel/bpf/bpf_struct_ops.c > > 1042 > 1043 int bpf_struct_ops_supported(const struct bpf_struct_ops *st_ops, u32 moff) > 1044 { > > 1045 void *func_ptr = *(void **)(&st_ops->cfi_stubs[moff]); The compiler warning can be fixed with: void *func_ptr = *(void **)(st_ops->cfi_stubs + moff); The patch looks good to me. I tested it with bpf qdisc, and it does what it is supposed to do by prohibiting users to attach to an operator whose cfi stub is not defined. Thanks, Amery > 1046 > 1047 return func_ptr ? 0 : -ENOTSUPP; > 1048 } > 1049 > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki
