Three decades later, journal communications of the association for computing machinery cacm 20. Modern symbolic execution austin cory bart cs6304 program analysis 11102015. In this work in progress, we consider here the case of guided dse, where the paths to enumerate should be part of a given program slice. Lecture 25 automated test generation using symbolic execution. If the correctness criteria for the given program is described by a set of test cases, we will show that. By cristian cadar and koushik sen symbolic execution. Symbolic execution for software testing in practice. Klee symbolic execution tester, llvm program analysis platform papers on automatic exploit construction using satsmt solvers. Rather than replace existing software testing techniques, such as test case writing, they complement existing software testing efforts in novel ways. A survey of new trends in symbolic execution for software testing. Symbolic execution is a program analysis technique that was introduced in the 70s 8,15,31,35,46, and that has found renewed interest in recent years 9,12,28,29,32,33,40,42, 43,5052,56,57. Three decades later cadar and sen a few billion lines of code later using static analysis. Discover deeper bugs with dynamic symbolic execution and. The challengesand great promiseof modern symbolic execution techniques, and the tools to help implement them.
Unit test data generation for c using ruledirected. 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. Within the latter domain of random test generation, current strategies for input. In software testing, symbolic execution is used to generate a test input for each feasible execution path of a program. Traditionally, fuzz testing tools apply random mutations to wellformed inputs of a program and test the resulting values.
Symbolic execution tree of function foobar given in figure 1. 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. Comprehensively testing software patches with symbolic. The main reason for the standardization of network protocols, like quic, is to ensure interoperability between implementations, which poses a. Symbolic execution is typically used in software testing to explore as many different program paths as possible in a given amount of time, and for each path to. Interoperabilityguided testing of quic implementations. Our group publishes in top venues in the areas of software engineering, software testing and verification, computer systems and computer security. In software testing, symbolic execution is used to generate a test input for each execution path of a program. Armando solarlezama in this lecture, professor solarlezama from mit csail presents the concept of symbolic execution. Improvements of directed automated random testing in test. Parallel symbolic execution for automated realworld. Generalized symbolic execution for model checking and testing. Coveragebased fuzz testing and dynamic symbolic execution are both popular program testing techniques.
Selecta formal system for testing and debugging programs by symbolic execution. We thank matt dwyer for his advice permission to make digital or hard copies of all or part of. Firmalice automatic detection of authentication bypass vulnerabilities in binary firmware driller. 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. The execution requires a selection of paths that are exercised by a set of data values. Generalized symbolic execution for model checking and testing sarfraz khurshid1, corina s. Symbolic execution is used to reason about a program pathbypath which is an advantage over reasoning about a program inputbyinput as other testing paradigms use e. Combining unitlevel symbolic execution and systemlevel. Augmenting fuzzing through selective symbolic execution aeg. However, if few inputs take the same path through the program, there is little savings over testing each of the inputs separately. Dynamic symbolic execution dse is an efficient smtbased path enumeration technique used in software testing. Role of symbolic execution in software testing, debugging.
Symbolic execution the symbolic execution of a program is described in this section in an ideal sense, and then, in section 6, a. We present an alternative whitebox fuzz testing approach inspired by recent advances in symbolic execution and dynamic test. C cadar, p godefroid, s khurshid, cs pasareanu, k sen, n. Three decades later abstract symbolic execution has garnered a lot of attention in recent years as an effective technique for generating highcoverage test suites and for finding deep errors in complex software applications. Unassisted and automatic generation of highcoverage tests for complex systems programs cadar et. Soft international symposium on software testing and analysis issta18. A feasible execution path is a sequence of true and false, where a value of true respectively false at the i th position in the sequence denotes that the i th conditional statement encountered along the execution path took the then respectively the else branch.
Symbolic execution for software testing in practice preliminary assessment. Unit testing is widely used in software development. In proceedings of the theory and practice of software, 14th international conference on tools and algorithms for the construction and. Symbolic execution property based testing ex3 due tonight. Mayur naiks lecture videos on software testing and analysis mary jean harrolds slides under the topic column on program analysis including datacontrol dependency, slicing, etc. We have developed symbolic java pathfinder, a symbolic execution framework that implements a nonstandard bytecode interpreter on top of the java pathfinder model checking tool. Symbolic execution has become an effective program testing technique, providing a way to automatically generate inputs that trigger software errors ranging from lowlevel program crashes to higherlevel semantic properties generate test suites that achieve high program coverage. Existing automated techniques, like model checking and symbolic execution, are highly effective cadar 2008, holzmann 2008, but their adoption in industrial generalpurpose software testing has been limited. Software testing debugging is extremely time consuming, and hence techniques to automate debugging or program repair are of value. The software reliability group at imperial college london has invested a significant amount of effort in the last few years on devising techniques and tools for comprehensively testing software patches. Three decades later cristian cadar, koushik sen communications of the acm cacm volume 56, issue 2, 20 safe software updates via multiversion execution petr hosek, cristian cadar international conference on software engineering icse 20 san francisco, ca, may 20. Abstract visual dramatization of intrusion detection software testing and reverse engineering of software can be aided by genetic algorithms known as fuzzing and concolic execution. Guided dynamic symbolic execution using subgraph control. Citeseerx document details isaac councill, lee giles, pradeep teregowda.
However, on their own, both techniques suffer from scalability problems when considering the complexity of modern software. Searchbased detection of deviation failures in the. One important activity in unit testing is automatic test data generation. Proceedings of the ieeeacm international conference on automated software engineering. Analyzing semantic correctness with symbolic execution. Unit testing only tests functions instead of the whole program, where individual functions typically have preconditions. Each execution state, labeled with an upper case letter, shows the statement to be executed, the symbolic store. Symbolic execution has been proposed over three decades ago but recently it. Hybrid testing methods attempt to mitigate these problems by leveraging dynamic symbolic execution to assist fuzz testing. Automatic exploit generation state of the art of war. A bibliography of papers related to symbolic execution. In this talk, i will discuss the use of symbolic execution for software testing, debugging and repair.