1. An article comprising at least one storage medium containing instructions that when executed cause a system to: initiate a linking procedure of a first routine to a shared library that stores the first routine and at least one other routine that the first routine is not authorized to call, wherein the linking procedure links the first routine to a stub library containing stub programs corresponding to one or more routines that the first routine is authorized to access; conclude that the first routine contains a call to the other routine for which a stub program is not provided in the stub library; and in response to concluding that the first routine contains a call to the other routine for which a stub program is not provided in the stub library: indicate a linking error; and end the linking procedure without linking the first routine to the shared library.