Are there tools that would create:  UML Structural Diagrams from Source Code.  UML Behavioral Diagrams from Binary executing on a arm / x86 system.  Sources would be in C &/ C++ &/ Python.Such tools would boost productivity while re-engineering (understanding existing software and modifying it.) on a Linux platform.
Re-engineering to create UML Diagrams from Source and Binary
tools;static analysis;dynamic analysis;processhacker
I did some work on modelling C programs sometimes back, I used this article as starting point,http://www.drdobbs.com/uml-for-c-programmers/184401948then evaluated few ide and found EA most fitting also IBM RSA has good support for modelling C programs. However what you will need to do is, formulate a way of modelling C programs in UML and then follow it, this is because C not being an Object Oriented language and UML being inherently Object oriented we need to device how we will represent a C construct in UML.hope this helps for C, for C++ EA and RSA's reverse engineering worsk well and not much effort is required as C.