Profiling a PostgreSQL function [duplicate]

Question

This question already has an answer here:

• Postgres query plan of a function invocation written in plpgsql 2 answers

if I use

explain (analyze true, verbose true, costs true, buffers true)
select * from mystoredprocedurefunction(arg1, arg2);

I do not get any information about what the server is actually doing inside my sp. Instead I get 5 rows describing that I invoked a function and that it took a long time. How do I look into my stored procedure and see what is going on? I have something very inefficient occurring.