Support for multiple client processes

[trungnt2910]

This looks like a duplicate of #492, but with a different use case.

I'm starting a Windows driver project, and I want to use the Linux kernel as a library, so I'm having a look at this project.

The driver needs to manage multiple client processes running in userland. The driver already knows how to intercept syscalls, and I intend to forward these syscalls to LKL.

How much work would be required to add support for multiple processes? For my use case, the driver lives in the kernel region, so it doesn't have to perform mapping hacks across the address space like UML.