Hi Andrii, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 0c18f29aae7ce3dadd26d8ee3505d07cc982df75 commit: f2644fb44de9abd54e57b55f584c7c67526f7c02 selftests/bpf: Add function linking selftest date: 9 weeks ago config: x86_64-rhel-8.3-kselftests (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/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout f2644fb44de9abd54e57b55f584c7c67526f7c02 # save the attached .config to linux build tree make W=1 ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): libbpf: failed to find BTF info for global/extern symbol 'my_tid' --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org