reproduce (this is a W=1 build):
        # https://github.com/avpatel/linux/commit/8b3427f4b14a75a64861188d771ad5fe6b32443b
        git remote add avpatel https://github.com/avpatel/linux.git
        git fetch --no-tags avpatel riscv_trace_support_v1
        git checkout 8b3427f4b14a75a64861188d771ad5fe6b32443b
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        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=$HOME/0day COMPILER=clang-16 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-16 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash samples/ftrace/