Based on a risk, select a subset of test suite to be executed for this cycle. Jul 19, 2016 the idea behind the use of symbolic executiontesting is to test the application by providing symbolic values than any specific data value. It can therefore be used to find performance bottlenecks, e. Symbolic execution is used in conjunction with an automated theorem prover or constraint solver based on constraint logic. Symbolic execution as empirical studies tool web application security checker enhancement to abstractionbased static analysis program synthesis tool all of these take advantage of sym exec strengths, and try to avoid drawbacks 7. Enhancing symbolic execution with builtin term rewriting and constrained lazy initialization. To deal with the complexities of systems code, exe models memory with bitlevel accuracy. An execution path is a sequence of true and false, where a value of true respectively false at the ith position in the sequence denotes that the ith conditional statement encountered along the execution. The resulting bounds are fitted to a function to obtain a prediction of the worst. Jun 06, 2017 symbolic execution is a powerful technique to systematically explore paths possibly all of a software program. Combining symbolic execution and searchbased testing for. Symbolic execution for software testing in practice. Symbolic execution is a software testing technique that substitutes the normal inputs into a program e. In software testing, symbolic execution is used to generate a test input for each execution path of a program.
In addition, symbolically executing programs or models with complex constraints or data structures is challenging 19, 60, e. Concolic testing a portmanteau of concrete and symbolic is a hybrid software verification technique that performs symbolic execution, a classical technique that treats program variables as symbolic variables, along a concrete execution testing on particular inputs path. Symbolic execution and recent applications to worstcase. Citeseerx citation query symbolic execution and program testing. In computer science, symbolic execution also symbolic evaluation is a means of analyzing a program to determine what inputs cause each part of a program to execute.
Role of symbolic execution in software testing, debugging. A survey of symbolic execution techniques roberto baldoni, emilio coppa, daniele cono delia, camil demetrescu, and irene finocchi, sapienza university of rome many security and software testing applications require checking whether certain properties of a. Instead of supplying the normal inputs to a program e. Symbolic execution is a popular program analysis technique introduced in the mid. In this article, we give an overview of modern symbolic execution techniques, discuss their key. Role of symbolic execution in software testing, debugging and. An interpreter follows the program, assuming symbolic values for inputs rather than obtaining actual inputs as normal execution of the program would, a case of abstract interpretation. Symbolic execution is a program analysis technique that was introduced in the 70s. Modelbased testing is an application of modelbased design for designing and optionally also executing artifacts to perform software testing or system testing. Symbolic execution for software testing in practice preliminary.
The idea behind the use of symbolic executiontesting is to test the application by providing symbolic values than any specific data value. Symbolic execution and model checking for testing request pdf. A survey of new trends in symbolic execution for software. Combining symbolic execution and searchbased testing for programs with complex heap inputs pietro braione.
Discovering software bugs via fuzzing and symbolic execution brian s. Symbolic execution and program testing people at vt. Some insights about symbolic execution i execute programs with symbols. Aug 30, 2016 importantly, we take a build security in mentality, considering techniques at each phase of the development cycle that can be used to strengthen the security of software systems. Symbolic testing and the dissect symbolic evaluation system. While the key idea behind symbolic execution was introduced more than three decades ago,6,12,23 it has only recently been. We describe techniques based on symbolic execution for finding software vulnerabilities that are due to algorithmic complexity. Symbolic execution for software testing eecs at uc berkeley.
A survey of new trends in symbolic execution for software testing and analysis. I cloud9 parallel symbolic execution, also supports threads i pex symbolic execution for. If the correctness criteria for the given program is described by a set of test cases, we will show that. Combining symbolic execution and searchbased testing issta17, july 2017. We now discuss prominent applications of symbolic execution techniques to these domains. Software security introducing symbolic execution youtube. We describe an approach to testing complex safety critical software that combines unitlevel symbolic execution and systemlevelconcrete execution for generating test cases that satisfy userspeci. Symbolic execution, searchbased software engineering acm reference format. Test execution is the process of executing the code and comparing the expected and actual results. Symbolic execution for testing complex software guide books. In this article, we give an overview of modern symbolic execution techniques, discuss their key challenges in terms.
Generalized symbolic execution for model checking and testing. In this paper, we propose a new approach to automatically generate test cases for programs with complex data structures as inputs. Citeseerx document details isaac councill, lee giles, pradeep teregowda. In software testing, symbolic execution is used to generate a test input for each feasible execution path of a program. Techniques for checking complex software range from model checking and static analysis to testing. The picture on the right depicts the former approach. We present a new tool, named dart, for automatically testing software that combines three main techniques. Software security basic symbolic execution youtube. This section briefly describes symbol, a symbolic execution testing system for cobol, built by the author. Traditional model checking, symmetry reductions, symbolic execution symbolicconcrete execution using abstract matching on the shape of the containers, random testing testing coverage statement, predicate results symbolic execution worked better than explicit model checking model checking with shape abstraction. The use of symbolic execution for testing of realtime safety.
This dissertation presents a novel symbolic execution technique for comprehensively testing complex software. Symbolic execution for software testing in practice imperial. Improving scalability of symbolic execution for software. Modern approaches, such as generalized symbolic execution gse 33 and.
This technique ensures high coverage and for finding deep errors in a very complex code or software applications. Instead of using concrete inputs, symbolic execution executes a program with symbolic inputs. Unassisted and automatic generation of highcoverage tests for complex systems programs. Abstract symbolic execution is a wellknown program analysis technique which represents program inputs with symbolic values instead of concrete, initialized, data and. Symbolic execution and program testing 1976 citeseerx. Jul 17, 2008 we describe an approach to testing complex safety critical software that combines unitlevel symbolic execution and systemlevel concrete execution for generating test cases that satisfy userspecified testing criteria. Using symbolic execution to improve modern fuzzing code.
I think symbolic execution can be used in many other interesting ways next. Following factors are to be considered for a test execution process. Watson research center this paper describes the symbolic execution of pro grams. Combining unitlevel symbolic execution and systemlevel. In particular, we have extended the java pathfinder model checking tool jpf with a symbolic execution capability 4,2 to enable test case generation for java programs. Software testingdebugging is extremely time consuming, and hence techniques to automate debugging or program repair are of value. Complexity vulnerability analysis using symbolic execution. In computer science, symbolic execution also symbolic evaluation is a means of analyzing. Importantly, we take a build security in mentality, considering techniques at each phase of the development cycle that can be used to strengthen the security of software systems. Generalized symbolic execution for model checking and testing sarfraz khurshid1, corina s. We provide a twofold generalization of traditional symbolic execution based approaches. If execution path depends on unknown, we fork symbolic executor at least, conceptually 5. We have developed symbolic java pathfinder a symbolic execution framework that implements a nonstandard bytecode interpreter on top of the java pathfinder model checking. After analyzing the advantages and disadvantages of fuzz testing and symbolic execution when testing a full system software stack, we realized that symbolic execution has the powerful ability to find corner bugs while spending a great deal of time on program analysis and constraint solving.
Improving scalability of symbolic execution for software with complex environment interfaces bucur, stefan. Symbolic execution is typically used in software testing to explore as many. Selecta formal system for testing and debugging programs by symbolic execution. The techniques use an efficient guided symbolic execution of a programme to compute bounds on the worst. We aim to use the power of exhaustive techniques, such as model checking and symbolic execution. During execution, a symbolic execution engine accumulates a. An interpreter follows the program, assuming symbolic values for inputs rather than obtaining actual inputs as normal execution of the program would. Complexity analysis with fuzzing and symbolic execution. How symbolic execution complements modern fuzzing what is symbolic execution.
In proceedings of 27th acm sigsoft international symposium on software testing and analy. Modern software systems, which often are concurrent and manipulate complex data structures must be extremely reliable. A feasible execution path is a sequence of true and false, where a value of true respectively false at the thi position in the sequence denotes that the ith conditional statement encountered along the. Symbolic execution stands out as an automated testing technique that has no false positives, it eventually enumerates all feasible program executions, and can prioritize executions of interest. Symbolic execution has gained much popularity in the recent past. The execution requires a selection of paths that are exercised by a set of data values. We present a novel framework based on symbolic execution, for automated checking of such systems. In this talk, i will discuss the use of symbolic execution for software testing, debugging and repair. None are aimed at commercial dp software and no symbolic execution testing system has previously been built to analyse cobol source programs. Finding bios vulnerabilities with symbolic execution and. During execution, a symbolic execution engine accumulates a set of constraints on the symbolic inputs.
Such vulnerabilities allow an attacker to mount denial. Symbolic execution cs252r spring 2011 contains content from slides by jeff foster. Here, there are all the inputs for which x is less than y and thus z gets the initial value of y, and all those inputs for which x is greater or equal to. Recent years have witnessed a surge of interest in symbolic execution for software testing, due to its ability to generate highcoverage test suites and find deep errors in complex software applications. We aim to use the power of exhaustive techniques, such as model checking and symbolic execution, to enable thorough testing of complex software. Models can be used to represent the desired behavior of a system under test sut, or to represent testing strategies and a test environment. We have developed symbolic java pathfinder, a symbolic execution framework that implements a nonstandard bytecode interpreter. Net i jcute symbolic execution for java i java pathfinder a model checker that also supports symbolic execution i symdroid symbolic execution on dalvik bytecode i kleenet testing interaction protocols for sensor network. Proceedings of the 8th usenix conference on operating.
Symbolic execution effectively enumerates all paths through a program, up to a userspecified bound. Recent years have witnessed a surge of interest in symbolic execution for software testing, due to its ability to generate highcoverage test suites and. Professor david brumley, advisor professor david andersen, faculty submitted in partial ful. Test generation using symbolic execution semantic scholar. Dec 09, 20 software testingdebugging is extremely time consuming, and hence techniques to automate debugging or program repair are of value.
We symbolically execute the target program to produce path conditions that characterise the structure of the inputs, and convert the path conditions into the objective function of an optimisation. Assign the test cases in each test suite to testers for execution. Symbolic java pathfinder symbolic execution of java. Keywords fuzzing,symbolicexecution,complexityanalysis,denialofservice acm reference format. Symbolic execution is a software testing technique that is useful to aid the generation of test data and in proving the program quality. Symbolic execution is a technique that as its name hints, allows symbolically executing each distinct path. Symbolic execution enhanced system testing intelligent systems. Data and lessons learned from a case study with an industrial software component. Symbolic execution is a testing technique where program is run through an interpreter, which allows for inputs to be symbolic, as opposed to concrete. While the key idea behind symbolic execution was introduced more than. Symbolic execution techniques can effectively handle structured inputs, but do not identify the sequences of method calls that instantiate the input structures through legal interfaces. When program execution branches based on a symbolic value, the system follows both branches paths and maintains a path condition for each.