Software fault injection

Although the effect of faults is increasing, the rate is not yet sufficient to test fault tolerant techniques at ground level. In order to do so, fault emulation and testing is necessary. In this Section, we will go over a few options to do so, such a software fault injection by simulation, fault injection in the FPGA s memory configuration bitstream and irradiation experiments. 

Tests which induce specific failure modes. For instance, use hardware/software fault-injection techniques to subject redundant diverse versions to anomalous behaviour. The effect of the injected faults is observed to determine if common mode failures have occurred. 

Software fault injection (Voas McGraw 1997) provides a means for dynamic demonstration that the required software quahty is achieved, in particular, software testabdity, robustness and fault tolerance requirements. Fault Injection is long extended... 

Leme, N. G. M. Martind, E Rubira C. M. F. 2001. A Software Fault Injection Pattern System. 8th Conference on Pattern Languages of Programs. 

Voas, X McGraw G. 1997. Software Fault Injection Inoculating Programs Against Errors. New York John Wiley Sons, Inc. 

Voas J M, McGraw G (1998) Software fault injection. Wiley Interscience Whittaker J (2003) How to break software. Addison-Wesley... 

This research described in this paper laid the groundwork for the next stage of our analysis of cyber-physical systems software fault injection into the cyber control. The insight gained into root causes of FACTS device failure will be used to further refine the reliability models, facilitating accurate quantitative analysis of reliability of the power grid. 

Both developers and testers use a wide variety of tools to help them test their software. Debugging versions of a product typically contain tens of thousands of checked assertion statements. Various program analysis tools have been developed to detect such things as the use of uninitialized variables. Debugging versions also typically contain code that checks for memory allocation errors and corrupted data structures. Yet another technique used is fault injection. Code is added to a system to artificially cause faults to occur in various subsystems and to produce incorrect input parameters to and output results from called functions. 

The book is organized as follows Chap. 2 presents the terminology and general concepts used in this work. Chapter 3 describes existing fault tolerant techniques for processors presented in the literature. Chapter 4 describes the fault tolerant techniques implemented in this work to detect transierrt fairlts in processors, from which two are known software-based and three are new lybrid techniques. Chapter 5 presents experimental fault injection campaigns for the implemented fairlt tolerarrt techniques. Chapter 6 presents the configuration bitstream fairlt injection campaign and results. Chapter 7 presents radiation experiments on some of the proposed techniques. Chapter 8 describes future work and concludes the book. 

Du, W. Mathur, A.P. 1998. Vulnerability Testing of Software System Using Fault Injection. COAST technical report. West Lafayette Purdue University. 

UML-based Fault Injection for Software Model Testing (FISMT)... 

The main characteristic of Software Implemented Fault Injection (SWIFI) is the capacity of injecting previously defined faults in any software accessible functional unit, like memories, registers, peripheral devices, etc. The objective of the injection is the detection of functional errors cansed by faults in HW or systematic errors in SW design. 

To provide fault injection capabdities, the EM component is included into the generic Fault Injection platform. The effective cost of this insertion imder a) the computational point of view and b) the complexity is meaningless and does not require big software changes. 

Software Implemented Fault Injectors (SWIFI) have a numerous advantages over other fault injection techniques [3]. One of the most important is the very high level of controllability over injected disturbances and observability of fault propagation and effects. In the research two fault injectors are used FITS and InBochs. 

Arlat, J., Crouzet, Y., Karlsson, J., FoUcesson, P., Fuchs, E., Leber, G.H. Comparison of physical and software implemented fault injection techniques. IEEE Transactions on Computers 52(9), 1115-1133 (2003)... 

Gawkowski, P., Sosnowski, J. Experiences with software implemented fault injection. In International Conference on Architecture of Computing Systems, pp. 73-80. VDE Verlag GMBH (2007)... 

Model-based development of software has become more and more common over the years. Software can be designed and verified using behavioral models developed in e.g. Simulink [1], which is one of the most popular tools for this purpose. For safety-related software developed in Simulink, compliance with recommendations from functional safety standards may be required. For example, if the international standards lEC 61508 [2] or ISO 26262 [3] are used, they require that systems shall be able to handle faults, and fault injection is either recommended or mandatory according to these standards. Fault injection is an experimental method to exercise and evaluate error detection and recovery mechanisms, and it can also be used in an iterative manner to improve software robustness. 

There have been some initiatives to develop fault injection support for models [4, 5, 6, 7], including the MODIH (MODel-Implemented Fault Injection) tool [8]. The setup and execution of new fault injection experiments for Simulink models using MODIFl is done in the same manner for any Simulink model. The analyses of the fault injection experiments can be more difficult since they are appUcation-specific and have to be tailored for each Simulink model. MODIFl analyses the output values for the experiments conducted on the Simulink model to determine failures (safety requirements violations). For a more detailed analysis, it is important to reveal error detection and propagation inside the software model. Hence, tool support that besides... 

A model-based approach for software development is commonly used in the automotive industry, and Simulink [1] and TargetLink [9] are two examples of tools that can be used to develop automotive software. MODIFI is a fault injection tool for dependability assessment of software developed as Simulink models. Using this tool, nonfunctional properties such as error detection coverage of fault tolerance mechanisms, can be tested using Simulink models as a complement to physical fault injection tests on the target system. This method makes it possible to perform fault injection testing in early phases of the development, and the same environment is used for the development of the software, as well as functional and non-functional testing. 

Traditionally, fault injection is used as a testing method for evaluation of fault tolerance in hardware or software. However, by using model-implemented fault injection (MUT) as implemented in the MODHT tool, fault injection can be used in early steps of software development. This is possible due to the increased utilization of model-based software development using tools like Simulink. Besides being used for validation of fault tolerance, MUT can be used to help developers focus on improvement of the most fault sensitive parts of a Simulink model. 

Operation of the PES with faults injected (hardware and/or software). These could allow comparison with criteria such as... 

The injection of software faults into a high-speed network system and assessment of the effect of those faults on the network dependability is presented in [15]. The types of faults analyzed in this paper include message corruption, message drop, and computer hanging, which are similar to the types of software faults that can occur in the cyber network of FACTS devices. The investigation presented concerns a purely cyber system. 

The work presented in this paper is part of an ongoing research project, and a continuation of the work presented in [3] and [4]. Significant advances have been made since the publication of [4], as we have investigated software failures in the cyber network of FACTS devices, and their effect on the physical portion of the power grid. The work presented here leads to the introduction of fault injection as an enabling tool for refinement of our rehabUity model for the power grid. 

Stott, D.T., Ries, G., Hsueh, M.C., Iyer, R.K. Dependability Analysis of a High-Speed Network Using Software-Implemented Fault Injection and Simulated Fault Injection. IEEE Transactions on Computers 47(1), 108-119 (1998)... 

Arlat, J., Aguera, M., Amat, L., Crouzet, Y., Martins, E., Powell, D. Fault Injection for Dependability Validation A Methodology and Some Applications. IEEE Transactions on Software Engineering 16(2), 166-182 (1990)... 

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