US Patent 7130786 Using kernel level simulation techniques to improve application program robustness

A method and system for simulating system conditions at a kernel-level is provided. In one aspect, process identifiers of processes for which simulation is to be performed are transmitted along with simulation pattern or rules from a user-space to a kernel space. Emulator in the kernel space intercepts system calls invoked by processes running in the user space. If the system calls originated from the one or more processes for which emulation was to be performed, return results according to the simulation pattern are generated and returned to the calling process.