Compilation and Binary Editing for Performance and Security

Traditionally, execution of a program follows a straight and inflexible path starting from source code, extending through a compiled executable file on disk, and culminating in an executable image in memory. This dissertation enables more flexible programs through new compilation mechanisms and binary editing techniques. To assist analysis of functions in binaries, a new compilation mechanism generates data representing control flow graphs of each function. These data allow binary analysis tools to identify the boundaries of basic blocks and the types of edges between them without examining individual instructions. A similar compilation mechanism is used to create individually relocatable basic blocks that can be relocated anywhere in memory at runtime to simplify runtime instrumentation. The concept of generating relocatable program components is also applied at function-level granularity. Through link-time function relocation, unused functions in shared libraries are moved to a section that is not loaded into the memory at runtime, reducing the memory footprint of these shared libraries. Moreover, function relocation is extended to the runtime where functions are continuously moved to random addresses to thwart system intrusion attacks. The techniques presented above result in a 74% reduction in binary parsing times as well as an 85% reduction in memory footprint of the code segment of shared libraries, while simplifying instrumentation of binary code. The techniques also provide a way to make return-oriented programming attacks virtually impossible to succeed

TechNews digests: Jan - Nov 2008

TechNews is a technology, news and analysis service aimed at anyone in the education sector keen to stay informed about technology developments, trends and issues. TechNews focuses on emerging technologies and other technology news. TechNews service : digests september 2004 till May 2010 Analysis pieces and News combined publish every 2 to 3 month

The Ecce and Logen Partial Evaluators and their Web Interfaces

We present Ecce and Logen, two partial evaluators for Prolog using the online and offline approach respectively. We briefly present the foundations of these tools and discuss various applications. We also present new implementations of these tools, carried out in Ciao Prolog. In addition to a command-line interface new user-friendly web interfaces were developed. These enable non-expert users to specialise logic programs using a web browser, without the need for a local installation

A system overview of the Aerospace Safety Research and Data Institute data management programs

The NASA Aerospace Safety Information System, is an interactive, generalized data base management system. The on-line retrieval aspects provide for operating from a variety of terminals (or in batch mode). NASIS retrieval enables the user to expand and display (review) the terms of index (cross reference) files, select desired index terms, combine sets of documents corresponding to selected terms and display the resulting records. It also allows the user to print (record) this information on a high speed printer if desired. NASIS also provides the ability to store the strategy of any given session the user has executed. It has a searching and publication ability through generalized linear search and report generating modules which may be performed interactively or in a batch mode. The user may specify formats for the terminal from which he is operating. The system features an interactive user's guide which explains the various commands available and how to use them as well as explanations for all system messages. This explain capability may be extended, without program changes, to include descriptions of the various files in use. Coupled with the ability of NASIS to run in an MTT (multi-terminal task) mode is its automatic accumulation of statistics on each user of the system as well as each file