Could you clarify what you mean by that? This does heavily rely on loaded code being position-independent, because the memory used will go into whatever regions `mmap(..., ~MAP_FIXED)` returns.
I think it was meant not in a literal sense. ASLR is meant to make it hard to access memory which isn't yours. Your system makes it easy to access memory which isn't yours.
I wonder if the Rust checker could be made "extra process" aware in your scenario and thus allow rust programs to "connect to each other" in this shared memory space.