reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-52-g1cf3d98c-dirty
        # https://github.com/intel-lab-lkp/linux/commit/1c7c3007ba3a3a40b3fae9fb688632d794e24846
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Christian-Brauner/tracefs-port-to-kernfs/20240131-214120
        git checkout 1c7c3007ba3a3a40b3fae9fb688632d794e24846
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=i386 olddefconfig
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=i386 SHELL=/bin/bash fs/tracefs/