reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-linux-gnu
        # https://github.com/robertosassu/linux/commit/804df4ecdaed5aab1b4ba876acd207195090d9cb
        git remote add robertosassu https://github.com/robertosassu/linux
        git fetch --no-tags robertosassu inode-free-security
        git checkout 804df4ecdaed5aab1b4ba876acd207195090d9cb
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash kernel/bpf/