fatelf-exec: Execute FatElf binaries

[M3Henry]

Thanks for your work coming up with a sensible spec. I stumbled across systemd-binfmt recently and remembered FatElf.

As it stands, fatelf-exec copies the contained ELF into an anonymous memory backed file and executes it. This works for statically linked binaries and dynamically linked binaries that are linked to normal ELF dynamic libraries. For the use case of FatElf dynamic libraries, this does not provide a solution, though it could be possible in theory to shim ld-linux.so somehow.

It turns out there is demand for this sort of thing. Though it seems one only gets support when done with clever tricks: APE