reproduce:
        # https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/commit/?id=30a377d0347bd7eda27eedf736f4b7789f7bac4e
        git remote add kees https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git
        git fetch --no-tags kees devel/overflow/wrap-around
        git checkout 30a377d0347bd7eda27eedf736f4b7789f7bac4e
        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