HDTrans

Abstract

Dynamic translation is a general purpose tool used for instrumenting programs at run time. Performance of translated execution relies on balancing the cost of translation against the benefits of any optimizations achieved, and many current translators perform substantial rewriting during translation in an attempt to reduce execution time. Our results show that these optimizations offer no significant benefit even when the translated program has a small, hot working set. When used in a broader range of applications, such as ubiquitous policy enforcement or penetration detection, translator performance cannot rely on the presence of a hot working set to amortize the cost of translation. A simpler, more maintainable, adaptable, and smaller translator appears preferable to more complicated designs in most cases.HDTrans is a light-weight dynamic instrumentation system for the IA-32 architecture that uses some simple and effective translation techniques in combination with established trace linearization and code caching optimizations. We present an evaluation of translation overhead under both benchmark and less idealized conditions, showing that conventional benchmarks do not provide a good prediction of translation overhead when used pervasively.A further contribution of this paper is an analysis of the effectiveness of post-link static pre-translation techniques for overhead reduction. Our results indicate that static pre-translation is effective only when expensive instrumentation or optimization is performed.

Indirect branch emulation techniques in virtual machines

“…Several authors [10,12,21,36] compare this technique to the Inline Caching mechanism developed for the object-oriented language Smalltalk-80. In object-oriented languages it is not always possible to determine, at compile time, to which class an object belongs, neither which implementation of a method it should call.…”

“…Sridhar et al [35,36] describe HDTrans, a dynamic binary translator that is performanceefficient, although it does not employ any code optimization technique. One of the reasons for its efficiency is the introduction of two novel indirect branch emulation techniques: the Sieve, for register-indirect jumps, and the Return Cache for return instructions (see Section 4.6 and Section 4.9).…”