There are also segmentation differences. Only one copy of the read-only data and code (aka text) segments are mapped into all programs which load the library.

There are also segmentation differences. Only one copy of the read-only data and code (aka text) segments are mapped into all programs which load the library. However, each program instance gets its own unique pages of read-write data. Those pages are always located at a fixed offset from their code segment. That way, modern CPUs can execute PC-relative instructions to generate their addresses. The global data segments for a module are always located at a fixed offset relative to the code pages. See ARMv8 `adrp` (address of PC-relative page), RISC-V `auipc` (add upper immediate to program counter), and x86-64 PC-relative addressing for some modern examples. Then go backwards in time and see how ARMv7 does it (literal pools) and how some earlier RISCs did it (Itanium and Alpha global pointer aka "gp", PowerPC table-of-contents register).