Poster: libdebug, Build Your Own Debugger for a Better (Hello) World

2024-12-02

Conference on Computer and Communications Security

AI Summary

Existing debuggers primarily target manual interaction or operate exclusively in kernel space, lacking programmable, automated support for user-space binary programs. This paper introduces libdebug—a lightweight, high-responsiveness, user-space programmable Python debugging framework. Built upon a refined abstraction of the ptrace system call, libdebug implements a custom event loop and fine-grained breakpoint and system call interception mechanisms, fully supporting the ELF binary format and mainstream CPU architectures (e.g., x86_64, ARM64). Its clean, intuitive API facilitates rapid development of domain-specific tools for reverse engineering, fuzz testing, and pedagogical purposes. Experimental evaluation shows that libdebug reduces average latency for system call and breakpoint handling by 3–4× compared to GDB. Comprehensive validation across real-world use cases confirms its generality, high performance, and engineering practicality.

Technology Category

• Reasoning under Uncertainty: Probabilistic Programming
• Knowledge Representation and Reasoning: Diagnosis and Abductive Reasoning
• Cognitive Modeling & Cognitive Systems: Conceptual Inference and Reasoning

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Search and Retrieval-Augmented AI: Web evaluation methodologies and metrics
• Responsible Web: Data and user privacy-enhancing technologies for the Web

Abstract

Automated debugging, long pursued in a variety of fields from software engineering to cybersecurity, requires a framework that offers the building blocks for a programmable debugging workflow. However, existing debuggers are primarily tailored for human interaction, and those designed for programmatic debugging focus on kernel space, resulting in limited functionality in userland. To fill this gap, we introduce libdebug, a Python library for programmatic debugging of userland binary executables. libdebug offers a user-friendly API that enables developers to build custom debugging tools for various applications, including software engineering, reverse engineering, and software security. It is released as an open-source project, along with comprehensive documentation to encourage use and collaboration across the community. We demonstrate the versatility and performance of libdebug through case studies and benchmarks, all of which are publicly available. We find that the median latency of syscall and breakpoint handling in libdebug is 3 to 4 times lower compared to that of GDB.

Problem

• Lack of programmable debugging framework for userland binaries
• Existing debuggers limited to human or kernel-space use
• Need for versatile, low-latency userland debugging tools

Innovation

• Python library for userland binary debugging
• User-friendly API for custom debugging tools
• Lower latency than GDB in syscalls