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Compilers should be correct. To improve the quality of C compilers, we created Csmith, a randomized test-case generation tool, and spent three years using it to find compiler bugs. During this period we reported more than 325 previously unknown bugs to compiler developers. Every compiler we tested was found to crash and also to silently generate wrong code(More)
Reliable sensor network software is difficult to create: applications are concurrent and distributed, hardware-based memory protection is unavailable, and severe resource constraints necessitate the use of unsafe, low-level languages. Our work improves this situation by providing efficient memory and type safety for TinyOS 2 applications running on the(More)
Knit is a new component definition and linking language for systems code. Knit helps make C code more understandable and reusable by third parties, helps eliminate much of the performance overhead of componentization, detects subtle errors in component composition that cannot be caught with normal component type systems, and provides a foundation for(More)
To report a compiler bug, one must often find a small test case that triggers the bug. The existing approach to automated test-case reduction, delta debugging, works by removing substrings of the original input; the result is a concatenation of substrings that delta cannot remove. We have found this approach less than ideal for reducing C programs because(More)
The software that runs on a typical wireless sensor network node must address a variety of constraints that are imposed by its purpose and implementation platform. Examples of such constraints include real-time behavior, highly limited RAM and ROM, and other scarce resources. These constraints lead to crosscutting concerns for the implementations of sensor(More)
The network and distributed systems research communities have an increasing need for " replayable " research, but our current experimentation resources fall short of reaching this goal. Replayable activities are those that can be re-executed, either as-is or in modified form, yielding new results that can be compared to previously obtained results.(More)
Aggressive random testing tools ("fuzzers") are impressively effective at finding compiler bugs. For example, a single test-case generator has resulted in more than 1,700 bugs reported for a single JavaScript engine. However, fuzzers can be frustrating to use: they indiscriminately and repeatedly find bugs that may not be severe enough to fix right away.(More)
Sensor network applications should be reliable. However, TinyOS, the dominant sensor net OS, lacks basic building blocks for reliable software systems: memory protection, isolation , and safe termination. These features are typically found in general-purpose operating systems but are believed to be too expensive for tiny embedded systems with a few(More)
Network testbeds like Emulab allocate physical computers to users for the duration of an experiment. During an experiment, a user has nearly unfettered access to the devices under his or her control. Thus, at the end of an experiment, an allocated computer can be in an arbitrary state. A testbed must reclaim devices and ensure they are properly configured(More)