CAREER: Building Immunity to Memory Management Bugs during Production Runs

软件在社会中的广泛使用对软件可用性产生了前所未有的需求。不幸的是，内存管理错误是常见软件缺陷的主要类别，严重影响系统可用性。此前的研究表明，内存管理错误占报告的软件故障的43%。根据美国计算机应急准备小组维护的漏洞笔记数据库，内存错误在最近的漏洞报告中占主导地位。内存错误仍然很普遍，在生产运行期间很难处理，主要原因有三个。首先，内存错误是确定性的，使传统的容错方法失效。其次，在生产运行期间表现出来的内存错误很难在异地复制，这使得它们很难诊断。第三，云计算和多核等现代计算趋势使软件变得更大、更复杂，导致内存错误更容易潜入领域。调查人员采用了一种系统的方法来在生产运行期间提供对内存错误的免疫力。其主要思想是在检测到内存错误或故障后进行在线诊断，然后生成运行时免疫补丁并将其应用于正在运行的程序，以生存并防止内存错误的发生或内存错误导致的故障。这项研究的关键在于以下协同推力：(1)运行时支持多样化的程序执行环境，以安全高效地生存并防止内存错误或故障的发生或故障，解决了内存错误的确定性问题；(2)低开销错误诊断的新算法，用于现场应用，以便于内存错误的复制和对现场错误/故障信息的最佳利用；(3)操作系统支持现代多核系统中多线程程序的轻量级检查点和重新执行机制。

The widespread use of software in our society has created unprecedented demand on software availability. Unfortunately, memory management bugs, a major category of common software defects, severely affect system availability. Previous studies have shown that memory management bugs account for 43% of the reported software failures. According to the Vulnerability Notes Database maintained by the U.S. Computer Emergency Readiness Team, memory bugs are dominant in recent vulnerability reports. Memory bugs remain prevalent and challenging to handle during production runs mainly because of three reasons. First, memory bugs are deterministic, failing traditional fault tolerance methods. Second, memory bugs manifested during production runs are hard to reproduce off-site, making them difficult for diagnosis. Third, modern computing trends such as cloud computing and multi-core enable larger and more complicated software, causing memory bugs to slip into the field more easily.This project addresses the above challenges. The investigator employs a systematic approach for providing immunity to memory bugs during production runs. The main idea is to perform online diagnosis once a memory bug or failure is detected, then generate and apply runtime immune patches to the running program for surviving and preventing memory bug occurrences or failures caused by memory bugs. The research hinges on the following synergistic thrusts: (1) runtime support of diversified program execution environments for safely and efficiently surviving and preventing memory bug occurrences or failures, which addresses the determinism issue of memory bugs; (2) new algorithms for low-overhead bug diagnosis, which are applied on-site for easy reproduction of memory bugs and best exploitation of on-site bug/failure information; (3) operating system support for lightweight checkpointing and re-execution mechanisms for multi-threaded programson modern multi-core systems.