libc {
  GLIBC_2.0 {
    # variables used for detecting cthreads
    _cthread_exit_routine; _cthread_init_routine;

    # cthreads functions with stubs in libc
    cthread_keycreate; cthread_getspecific; cthread_setspecific;
    __libc_getspecific;

    # functions with a weak definition in the dynamic linker
    __getcwd; __mmap;
  }
}

ld.so {
  GLIBC_2.0 {
    # variables that must be shared with libc
    __hurd_sigthread_stack_base; __hurd_sigthread_stack_end;
    __hurd_sigthread_variables;
    __hurd_threadvar_stack_mask;  __hurd_threadvar_stack_offset;

    # functions that must be shared with libc
    __close; __fxstat; __getcwd; __getpid; __libc_read; __libc_write;
    __lseek; __mmap; __open; __xstat;
    _exit; _hurd_intr_rpc_mach_msg;
    abort; 
  }
}