Hi Daniel, Thank you for the patch! Yet something to improve: [auto build test ERROR on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Daniel-Xu/bpf-Remove-duplicate-PTR_TO_BTF_ID-RO-check/20220823-032643 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master config: x86_64-rhel-8.3-kselftests (https://download.01.org/0day-ci/archive/20220902/202209022000.s58TmR9h-lkp@xxxxxxxxx/config) compiler: gcc-11 (Debian 11.3.0-5) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/496ec6d75c8e8758f93c6b987eee83713c911a05 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Daniel-Xu/bpf-Remove-duplicate-PTR_TO_BTF_ID-RO-check/20220823-032643 git checkout 496ec6d75c8e8758f93c6b987eee83713c911a05 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): ld: net/core/filter.o: in function `tc_cls_act_btf_struct_access': >> net/core/filter.c:8644: undefined reference to `nf_conntrack_btf_struct_access' ld: net/core/filter.o: in function `xdp_btf_struct_access': include/net/net_namespace.h:369: undefined reference to `nf_conntrack_btf_struct_access' pahole: .tmp_vmlinux.btf: No such file or directory .btf.vmlinux.bin.o: file not recognized: file format not recognized vim +8644 net/core/filter.c 8632 8633 static int tc_cls_act_btf_struct_access(struct bpf_verifier_log *log, 8634 const struct btf *btf, 8635 const struct btf_type *t, int off, 8636 int size, enum bpf_access_type atype, 8637 u32 *next_btf_id, 8638 enum bpf_type_flag *flag) 8639 { 8640 if (atype == BPF_READ) 8641 return btf_struct_access(log, btf, t, off, size, atype, next_btf_id, 8642 flag); 8643 > 8644 return nf_conntrack_btf_struct_access(log, btf, t, off, size, atype, 8645 next_btf_id, flag); 8646 } 8647 -- 0-DAY CI Kernel Test Service https://01.org/lkp