Embedding Program Traits

Embedding of marker symbols for dynamic detection of program traits

Build

• Build with cmake: mkdir build && cd build && cmake .. && make cmake options:
  • HOOK_DLOPEN: disable hooking of dlopen (default On)
  • HOOK_MPROTECT: disable hooking of mprotect (default On)
  • BUILD_MPI_EXAMPLES: enables building of MPI examples. This builds MPICH MPI implementation and a wrapper showcasing how MPI could use the trait embedding mechanism with MPI Mini-Apps (default Off)
• run tests with ctest

Usage

Include Markers

In the program/library that one wants to include a trait marker for my_trait

• include markers.h
• use marker(my_trait) macro, one can include multiple trait markers.

Analyze Traits

The program or library that analyzes if the trait my_trait holds for all parts of the program uses the libancor_programm_traits library to inquire about the traits:

• allocate a trait_options struct
• Set up the data structure with the relevant settings:
  • char* name: name of the marker (the same one that is used in the marker marco)
  • char** symbols_require_trait: list of symbols that require this trait or NULL if the trait always needs to be present. This means that a trait is considered to be irrelevant if none of these symbols are found.
    • unsigned int num_symbols_require_trait: number of entries in that list
  • bool skip_main_binary: True if the trait should not be checked for the main binary and only the linked libraries, false otherwise.
  • bool check_for_dlopen: Continuously monitor if the trait is still valid after loading additional libraries with dlopen, print an error message and exit if a trait violation is found.
  • bool check_for_mprotect: Continuously monitor if the trait is still valid after it is marked as executable with mprotect, print an error message, and exit if trait violation is found. The current implementation does not actually check for trait violation but assumes one on marking memory as executable.
  • char** libraies_to_skip: path to .so files to skip analysis of (and assume trait is fulfilled). E.g. if the library currently checking for the traits has dlopen to load some implementation on demand, one could skip checking of this dlopen
    • unsigned int num_libraies_to_skip:number of entries in that list
• call register_trait() with the trait_options data structure as the argument. This will return a handle, the options may be freed at that point
• use check_trait() with the handle as an argument to check if the trait is fulfilled.
• remove_trait() on this handle will free all resources used and remove the checking for dlopen and mprotect for this trait.

Evaluation

Evaluation scripts are in the performance-evaluation directory. Run the Python script evaluation_runner.py in order to collect performance data. This will generate and execute test programs that link to randomly installed libraries (no library is actually called). These results can be visualized with the visualize_results.py script.