Nikita Karetnikov <nik...@karetnikov.org> skribis: >> For the purposes of bootstrapping GHC, I would rather steal whatever >> trick Nixpkgs uses, though. :-) > > I can’t find anything relevant there. I suppose that Nix people don’t > have to touch those binaries since they have ‘/bin/sh’ in a chroot.
What string exactly are you trying to patch? Just /bin/sh? In which binary? >> ELF tools like Andy Wingo’s tools being added to Guile 2.1, or maybe BFD >> (part of Binutils), might allow you to modify the ELF string table that >> contains string constants. > > Are you talking about the (system vm elf) module? I think so. > I’ve been trying to cook a patch but haven’t succeeded yet. Even > though I’ve looked through the ELF spec and this handy tutorial [1], > some things are still not clear. [...] > For instance, in order to change the “Hello” part, I have to adjust the > corresponding section (i.e., “.rodata”). Assuming that sections are > stored in order, I have to modify the offsets of the subsequent sections > and the offset of the section header table itself if I change the size > of “.rodata.” Finally, I can combine the changed executable header > (contains the offset of the section table header), the sections, and the > section table header. > > Is it correct? I’m not sure about the details. I would have expected tools like BFD or libelf to provide the necessary support to make this kind of operation easier, but I’ve never tried myself. Ludo’.
