README

librunt is a small library for building extensions to the ELF-level process runtime typically implemented by a dynamic linker.

The main parts are:

• relf.h, an inlines-only header for introspecting on ELF-level structures within a process (usable without linking in librunt)

• {bitmap,bitops,vas,maps}.h -- utility code

• librunt.h -- calls for querying addresses (think: souped-up dladdr)

• dso-meta.h -- extended per-DSO metadata (think: souped-up link.h)

To work, librunt must be preloaded (e.g. as librunt_preload.so) into the process. One day soon it should be possible to use libgerald to build a new dynamic linker, runtld.so, which may be a nicer interface.

You can also use librunt as a basis for an extended runtime that does more interesting things. One example is libsystrap, which lets you trap system calls (e.g. it includes an in-process system call tracer as a demo application, basicallyj a "faster strace"). liballocs and (transitively) libcrunch are also instances of this (or will be, once I backport liballocs to use librunt... most of librunt's code originates in liballocs).