reproduce:
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=02b4e126e6a5f5552da2ccec47a028984d2d9654
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 02b4e126e6a5f5552da2ccec47a028984d2d9654
        make W=1 O=/tmp/kselftest headers
        make W=1 O=/tmp/kselftest -C tools/testing/selftests
        make W=1 O=/tmp/kselftest -C tools/testing/selftests/bpf