The user_rdpmc Linux Kernel Module - Modified by Brad Morgan

A simple Linux kernel module which, when loaded, allows ring 3 (userspace) programs to use the RDPMC assembler instruction by flipping the PMC flag in the CR4 register.

This module only makes sense on an x86 machine.

Building

Run ./build.sh. This will install dependencies and build the kernel module and a test program.

Using

You can either use install.sh or the sudo insmod user_rdpmc.ko && sudo modprobe msr command to insert the kernel module into your current OS session.

However, when you restart, it will be removed, this is not a permanent switch for security reasons. If you want that, you will need to do that yourself.