tree: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git for-next head: 35cba2988fc65239d10566edc03cc0978382c25f commit: 33c5cb36015ac1034b50b823fae367e908d05147 [1055/1059] bpf: Consolidate task_struct BTF_ID declarations config: x86_64-randconfig-p001-20210825 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=33c5cb36015ac1034b50b823fae367e908d05147 git remote add bpf-next https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git git fetch --no-tags bpf-next for-next git checkout 33c5cb36015ac1034b50b823fae367e908d05147 # save the attached .config to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): ld: kernel/bpf/task_iter.o: in function `task_iter_init': >> kernel/bpf/task_iter.c:593: undefined reference to `btf_task_struct_ids' >> ld: kernel/bpf/task_iter.c:598: undefined reference to `btf_task_struct_ids' ld: kernel/bpf/task_iter.c:604: undefined reference to `btf_task_struct_ids' >> ld: kernel/bpf/bpf_task_storage.o:(.rodata+0x110): undefined reference to `btf_task_struct_ids' ld: kernel/bpf/bpf_task_storage.o:(.rodata+0x170): undefined reference to `btf_task_struct_ids' ld: kernel/bpf/stackmap.o:(.rodata+0x328): more undefined references to `btf_task_struct_ids' follow vim +593 kernel/bpf/task_iter.c 588 589 static int __init task_iter_init(void) 590 { 591 int ret; 592 > 593 task_reg_info.ctx_arg_info[0].btf_id = btf_task_struct_ids[0]; 594 ret = bpf_iter_reg_target(&task_reg_info); 595 if (ret) 596 return ret; 597 > 598 task_file_reg_info.ctx_arg_info[0].btf_id = btf_task_struct_ids[0]; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org