Production-Oriented Extensions for a User-Space Runtime Function Interposition Framework

Abstract

The runtime function interposition allows for changing of running applications without a complete service restart. The patching mechanism is basic; while it allows function redirection to be done in a way that is safe for the instructions, it is also important for practical deployment to have monitoring, authentication, validation, rollback and administrative control. It is an extension of a user space runtime interposition framework for x86-64 Linux userspace and production mechanisms for patch deployment that provide more safety and observability. The proposed method will take runtime measurement metrics, administrative interface, patch registration and backup management, authentication and signature verification, canary validation, and automatic rollback and place them in the current patching pipeline. Process control is implemented via ptrace, instruction-boundary via Capstone, and function redirection via inline trampolines. The extended workflow first resolves the target symbol, checks the patch, suspends and audits the application threads and saves the original instructions, adds the trampoline and restores the application's execution. The patch can then be kept in place in the post deployment environment or automatically reverted to the original implementation if a canary failure occurs. These extensions provide better observability, recovery and operational reliability of live patching while maintaining the light weight user space architecture.