Determine LD_PRELOAD'ed symbols. (UPDATE)

[Marcin]

Hello Hackers!,

My first post got stuck waiting for moderator, and after some investigation 
I'd like to ask a bit more substantial question on the topic anyway:

With program A ptrace'ing program B which runs with LD_PRELOAD'ed library libC.so,
how can i find from program A where functions from libC are located in B's memory?

The dump generated with LD_DUMP_REL_PRE shows only symbols which already were in B,
but were masked by LD_PRELOAD'ing libC.so, does it mean that other symbols exported 
by libC.so are unaccessible from B? If not, where to search for their locations?
Will sections in B and libC.so give any hints?

Pointers to doc/code (but please something smaller than src/libexec/rtld-elf ;>) welcome.

-- 
m.
Brain power of a glass of water.