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In survivability management systems, some management entities reside on application hosts that are not necessarily trustworthy. The integrity of these software entities is essential to the security of the network management scheme. In this talk, I present a novel framework to facilitate software security against malicious execution environments. The approach

Coverage testing techniques, such as statement and decision coverage, play a significant role in improving the quality of software systems. Constructing a thorough set of tests that yield high coverage, however, is often avery tedious, time consuming task. In this paper we present a technique to find a small subset of a program's statements and decisions with the property that covering the subset implies covering the rest. We introduce the notion of a mega block which is a set of basic blocks spanning multiple procedures with the property that one basic block in it is executed iff every basic block in it is executed. We also present an algorithm to construct a data structure called the global dominator graph showing dominator relationships among mega blocks. A tester only needs to create test cases that are aimed at executing one basic block from each of the leaf nodes in this directed acyclic graph. Every other basic block in the program will automatically be covered by the same test set.

This paper describes a compiler-based approach to checkpointing for process recovery. The implementation is transparent to both the programmer and the hardware. The compiler-generated sparse potential checkpoint code maintains the desired checkpoint interval. Adaptive checkpointing reduces the size of the checkpoints. Training is used to select low-cost, high-coverage potential checkpoints. The problem of selecting potential checkpoints is shown to be NP-complete, and a heuristic algorithm is introduced that determines a quick suboptimal solution. These compiler-assisted checkpointing techniques have been implemented in a modified version of the GNU C (GCC) compiler. Experiments involving the modified version of the GCC compiler on a Sun SPARC workstation are summarized

In this paper we present techniques to #nd subsets of nodes of a #owgraph that satisfy the following property: A test set that exercises all nodes in a subset exercises all nodes in the #owgraph. Analogous techniques to #nd subsets of edges are also proposed. These techniques may be used to signi#cantly reduce the cost of coverage testing of programs. A notion of a super block consisting of one or more basic blocks is developed. If any basic block in a super block is exercised by an input then all basic blocks in that super blockmust be exercised by the same input. Dominator relationships among super blocks are used to identify a subset of the super blocks whose coverage implies that of all super blocks and, in turn, that of all basic blocks. Experiments with eight systems in the range of 1-75K lines of code show that, on the average, test cases targeted to cover just 29# of the basic blocks and 32# of the branches ensure 100# block and branchcoverage, respectively.

Program development, debugging, and maintenance can be greatly improved by the use of software tools that provide information about program behavior. This thesis focuses on a number of useful software tools and shows how their efficiency, generality, and precision can be increased through the use of control-flow and control dependence analysis. We consider two classes of tools: execution measurement tools, which collect information about a particular program execution; and program analysis tools, which provide information about potential program behavior by statically analyzing the program. We consider three tools that measure aspects of a program's execution: profiling, tracing, and event counting tools. We describe algorithms for profiling and tracing programs that use a combination of control-flow analysis and program instrumentation to produce exact profiles and traces with low run-time overhead. Rather than record information at every point in a program, the algorithms record info...