patchelf VS eresi

I mean, we don't have to hack the elf loader if we just rewrite every elf binary using patchelf: https://github.com/NixOS/patchelf

The parent commenter is already suggesting "just run a regex", so it seems like a trivial extension to their simple solution to "just run patchelf on every binary on your system"

Patching paths in text files typically used substituteInPlace (including in cowsay). For dynamic libraries, patchelf is typically used.

Install patchelf.

Thank you! I followed the instruction here, but it looks like I didn't actually install it, because my pacman -Q patchelf did not find anything. Maybe I was missing a dependency. Also, it was late so I didn't pay attention to warnings at the time.

How does an article on NixOS talk about the `rpath` issue without also mentioning the `patchelf` utility that NixOS developers created to solve this issue? It's a small tool that lets you modify ELF executables and binaries. It's also the recommended way for NixOS users to modify binaries to work properly.

https://github.com/NixOS/patchelf

So install it? https://github.com/NixOS/patchelf

NixOS doesn't have stable paths to shared libraries like macOS or other linux distributions (and this is the core feature) and always need to patch elf for current paths ( https://github.com/NixOS/patchelf ).

I built a (research) library a few years ago to rewrite ELF binaries; our research projects ran into a lot of limitations with doing incremental patches to a binary (ELF has a lot of redundant representations of the same data). For us, parsing the binary into a normalized representation, modifying that, and re-serializing worked — we could make more intrusive changes to the binary, and (almost? I don’t recall anything breaking) everything in the Debian repos still ran after the binaries has been rewritten.

I expect the library is now woefully out of date, and documentation is mostly in the form of conference talk slides:

https://github.com/jbangert/mithril

there’s also https://github.com/aclements/libelfin (parsing only, supports dwarf); https://github.com/bx/elf-bf-tools (Turing machine inside elf relocations) and of course the “olg guard” of ELF reversing tools ERESI/elfsh (website seems down; GitHub mirror on https://github.com/thorkill/eresi).