For comprehensive analysis of all executable code, and fast turn-around time for transformations, it is essential to operate directly on binaries to enable profiling, security hardening, and architectural adaptation. Disassembling binaries is difficult, and prior work relies on a process virtual machine to translate references on the fly or inefficient binary code patching. Our Egalito recompiler leverages metadata present in current stripped x86_64 and ARM64 binaries to generate a complete disassembly, and allows arbitrary modifications that may affect program layout without any constraints from the original binary. We utilize our own layout-agnostic intermediate representation, which is low-level enough to make the regeneration of output code predictable, yet supports a dual high-level representation for sophisticated analysis. We demonstrate nine binary tools including a novel continuous code randomization technique where Egalito transforms itself, and software emulation of the control-flow integrity in upcoming hardware. We evaluated Egalito on a large set of Debian packages, completely analyzing 99.9% of a selection of 867 executables and libraries; a majority of 149 applicable Debian packages pass all tests under Egalito. On SPEC CPU 2006, thanks to our binary optimizations, Egalito actually observes a 1.7% performance speedup.

The goal of this paper is to achieve hard real-time processing with admitting as many tasks as possible on simultaneous multithreaded (SMT) processors. For this goal we propose U-link scheduling scheme that determines the co-scheduled set that is the fixed combinations of co-scheduled tasks to bound the task execution time. Also we present practical algorithms, RR-DUP for building co-scheduled sets and UL-EDF for task scheduling. The performance evaluation shows that UL-EDF with RR-DUP outperforms the conventional scheduling algorithms, EDF-FF and EDF-US, in the point of execution time stability, task rejection ratio and deadline miss ratio.

Imprecise computation is known as an effective technique for dynamically resolving trade-offs between the amount of resources and the quality of the result. However, its implementation and operating system support methods have not been exploited enough from a practical point of view. This paper presents a new approach taken in the RT-Frontier operating system to support imprecise computation. Applications that allow imprecise computation are first transformed to tasks composed of three parts based on an extended imprecise computation model. All tasks are then uniformly scheduled according to a novel scheduling algorithm called Slack Stealer for Optional Parts (SS-OP). The SS-OP algorithm is designed to handle imprecise computations with small overhead, which is at a comparable level of that of the Earliest Deadline First (EOF) algorithm. The results of experiments show that the presented approach is cost-effective enough to be considered as a practical basis for embedded real-time systems.