Code to reproduce the vmprof & libunwind related segfault
The segfault occurs, when vmprof calls unw_get_proc_name_by_ip with an address of a function from libffi.so, which is not exposed in the symboltable.
You need a recent, self built version of libunwind
And the libffi shared object (which comes from a from a PyPy nightly build) incuded in this Repo, as the segfault only occurs with that version oflibffi.so.
Then you need to set the path to libffi for dlopen in reproducer.c
Finally compile and run reproducer.c