stephenrkell/libx86emulate

Keir Fraser's x86-on-x86 emulator from the Xen hypervisor, hacked in various ways (currently for decode-only operation)

This code was forked from the Xen hypervisor version 4.5.1, and modified
by Stephen Kell for use as a simple instruction decoder.

BEWARE: this code has a history of security vulnerabilities when used in
security-critical applications (e.g. inside the hypervisor, emulating
instructions). Use it at your own risk.

My interest in the code is that it's the most compact implementation of
x86 I'm aware of, and that it's written in C with no external
dependencies. I currently use it in my libsystrap project, only for
decode, and in user processes (a much safer proposition than
in-hypervisor emulation!). 

The intention is to backport later changes from Xen (whose version 4.5.1
dates from mid-2016), restore emulation capability, and add some very
basic/limited symbolic execution support for a subset of instructions,
to support a few binary analysis applications. Patches in support of the
above are welcome. Again, a key goal is to keep things simple enough
that the code can easily be linked in to a tool or runtime written in C,
in contrast to full-scale binary analysis systems like BAP.

Like Xen, the licence is "GPLv2 or later". See LICENSE.gpl2. I might be
able to license my changes differently if that would help you (thought I
doubt it).

Stephen Kell
7th April 2020