The behavior of dlsym(RTLD_NEXT, ...) is defined to search for the symbol
starting at the library that contains the caller:

     In the latter [RTLD_NEXT] case dlsym() will search for the named symbol
     in the objects that were loaded following the object from
     which the dlsym() call is being made. If these subsequent
     objects were loaded from dlopen() calls, dlsym() will search
     the object only if the caller is part of the same dlopen()
     dependency hierarchy, or the object was given global search
     access (see dlopen() with reference to the mode
     RTLD_GLOBAL).

The wrapper for dlsym() in green thread's breaks this, resulting in the
caller always being the library that contains iomgr.o. A library,
such as libawt.so, could call _dlsym directly, but then it would bypass the
wrapper and cause synchronization problems.

dean.long@Eng 1998-08-31