reproduce (this is a W=1 build):
        # https://github.com/avpatel/linux/commit/3889440d4d89d7eed212c92d6b46a87676fac5a9
        git remote add avpatel https://github.com/avpatel/linux.git
        git fetch --no-tags avpatel riscv_trace_support_v6
        git checkout 3889440d4d89d7eed212c92d6b46a87676fac5a9

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=xtensa olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=xtensa SHELL=/bin/bash drivers/hwtracing/gtrace/