reproduce (this is a W=1 build):
        # https://github.com/avpatel/linux/commit/badc75240dd73faad1081d9c12b9cd0f9cc6a145
        git remote add avpatel https://github.com/avpatel/linux.git
        git fetch --no-tags avpatel riscv_trace_support_v6
        git checkout badc75240dd73faad1081d9c12b9cd0f9cc6a145

        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv-linux-gnu
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # apt-get install sparse
        # sparse: v0.6.5-rc1-21-g84ec0658

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=riscv SHELL=/bin/bash kernel/trace/