Research On Control Flow Error Checking Algorithm Based On Assembly Language

As the reducing of feature size of Integrate Circuit,power supply voltage andthreshold voltage,processors became more sensitive to noise disturbances such ascrosstalk,EMI radiation and particle radiation.The computer reliability problemscaused by hardware transient fault are more and more important.Especially inradiation environments,hardware transient fault produced by particle radiation isthe one of the most important elements which influences the computer systemreliability.Using radiation-hardened components in radiation environments canprevent hardware transient fault.But because of the high price,low capability andhuge power consumption,they are not adaptable for today's high-performancecomputing.With the high-performance,low price and low power consumptioncharacters,software and hardware technology on COTS compoents can toleratehardware transient fault and improve system reliability.Thus COTS could be usedin radiation enviroments.Among the hardware Transient Faults,the mostdamaging fault is attributed to control flow jump error.In order to reduce theinfluence made by this kind of fault,the dissertation mainly discusses control flowerror checking algorithm and its evaluation method.The research object of control flow error checking algorithm mainly includesthe high-level language and assembly language.Assembly language-based controlflow error checking algorithms are easier to implement,of which the systemperformance and undetected error ratio are both less than those of high-levellanguage-based algorithms.So the dissertation will focus on assemblylanguage-based control flow error checking algorithms.This kind of algorithmsmainly uses signature technology,solves four aspects of problems:particle size ofchecking,the express of signature information,the location of checkinginstructions and the signature checking method.This dissertation researches theabove questions,and presents an improved algorithm.In order to get atheoretically more accurate analysis of the checking capabilities of control flowchecking algorithm,this dissertation further improves the existing model onverifying control flow error checking ability.At the same time,most of the control flow error checking algorithms do not have the ability of recovery,how tocombine the characteristics of microprocessor architecture to complete the controlflow error recovery is a problem worth studying.In response to these problems,the main contents are as follows:(1) For the traditional model seldom considers the influence on the checkingability of the algorithm,caused by the added checking instructions,in order toanalyze the checking capabilities of control flow checking algorithm moreaccurately,this dissertion researches the verifying model on control flow errorchecking ability.(2) Since the assembly language-based CFCSS algorithm is more practical,this dissertation researches the checking confusion and checking error problem ofit.At the same time,in order to reduce system power consumption and checkingpoints,this dissertation presents LPICFCSS algorithm without influencing thecontrol flow error checking ability by modifying the particle size;In order toimprove control flow error checking ability and eliminate the redundantdependence among basic blocks,this dissertation researchs the signatureexpression and checking method,and presents the assembly language-basedDPNCFC algorithm.(3) Signature-based control flow error checking algorithm ensures thechecking location when it is compiled,that leads to the delay discovery of fault,and the reduce of system reliability.At the same time,since this kind of algorithmstreats the basic block as the basic test unit,the control flow jump error inside basicblock can not be checked out without the redundant checking instructions.For theabove two points,this dissertation researches the control flow error checkingalgorithm from the soft-hard view.(4) Since most control flow checking algorithms do not have fault tolerancecapability,in order to combine the control flow error checking algorithm andbreakpoint recovery technology closer,the dissertation uses hard-soft method toresearch control flow error tolerant method on the R80515 architecture.