reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-47-g365b9520-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux.git/commit/?id=14f919869f407fb2e693e4edbe541124d5eda2c6
        git remote add jlayton https://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux.git
        git fetch --no-tags jlayton leases
        git checkout 14f919869f407fb2e693e4edbe541124d5eda2c6
        # 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/lockd/ fs/nfs/ fs/smb/client/