reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install um cross compiling tool for clang build
        # apt-get install binutils-um-linux-gnu
        # https://github.com/smfrench/smb3-kernel/commit/d2b8db9f4873a117bb3307b8b8063bc647c07492
        git remote add smfrench-smb3 https://github.com/smfrench/smb3-kernel.git
        git fetch --no-tags smfrench-smb3 ksmbd-for-next-next
        git checkout d2b8db9f4873a117bb3307b8b8063bc647c07492
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-16 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=um olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-16 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=um SHELL=/bin/bash fs/smb/server/