/usr/lib/linux-tools/3.13.0-157-generic/perf is in linux-tools-3.13.0-157-generic 3.13.0-157.207.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/linux-tools/3.13.0-157-generic/../../linux-tools-3.13.0-157/perf