Research on CPU Instruction Security

Based on the research of abnormal instruction, Meltdown, Spectre, undocumented instruction and so on in the processor architecture, this paper considers that instruction security is one of the core issues of processor security. Firstly, this paper analyzes the instruction execution standard, optimization technology and the relationship between instruction and microinstruction, and then summarizes four existing security problems including instruction violation description, utilization of optimization technology, hijacking updating mechanism, undocumented instruction. Then, from the mitigation measures and hardware protection technologies, the security measures for the instruction problems are explained. Finally, it concludes that the research on undocumented instruction, semantic ambiguity of documented instruction and reverse analysis of CPU internal mechanism are the development trends of future security research.