DOCSLIB.ORG

Automated Breakpoint Generation for Debugging

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Automated Breakpoint Generation for Debugging JOURNAL OF SOFTWARE, VOL. 8, NO. 3, MARCH 2013 603 Automated Breakpoint Generation for Debugging Cheng Zhang1;3, Juyuan Yang2, Dacong Yan4, Shengqian Yang4, Yuting Chen2 1Department of Computer Science & Engineering and 2School of Software, Shanghai Jiao Tong University 3State Key Laboratory of Computer Science, Institute of Software, Chinese Academy of Sciences, Beijing, China 4Computer Science and Engineering Department, Ohio State University Email: [email protected], [email protected] fyan, [email protected], [email protected] Abstract— In debugging processes breakpoints are fre- for the subsequent debugging work. Some modern IDEs, quently used to inspect and understand the run-time pro- such as Eclipse1, provide the functionality to export and gram behavior. Although modern development environments import breakpoints, facilitating reuse and sharing of them. provide convenient breakpoint utilities, it mostly requires considerable human effort to create useful breakpoints. Additionally, we believe that breakpoints can also be Before setting a breakpoint or typing a breakpoint condition, automatically generated to further accelerate debugging developers usually have to make some judgements and processes. hypotheses based on their observations and experiences. To reduce the manual effort of debugging, researchers To reduce such kind of effort, we propose an approach have proposed a variety of automated debugging tech- to automatically generating breakpoints for debugging. We combine the nearest neighbor queries method, dynamic niques. Some techniques [5]–[8] focus on the abnor- program slicing, and memory graph comparison to identify mity of execution traces by collecting and analyzing suspicious program statements and states. Based on this the information of executions of the passing and failing information, breakpoints are generated and divided into test cases. Various measurements are taken to indicate two groups, where the primary group contains conditional the statements that are more relevant to failing runs breakpoints and the secondary group contains unconditional ones. We implement the presented approach on top of and identify the most relevant statements as the places the Eclipse JDT platform. Our objective experiments and where the faults reside. Another group of techniques put user study indicate that the generated breakpoints can be emphasis on the abnormal run-time program states [9]– effective in aiding debugging work. [11]. They observe the selected program states at certain Index Terms— software debugging, breakpoint generation locations and identify the most suspicious states which are much more likely to appear in failing runs. Ko and Myers [12] view the debugging process as a question I. INTRODUCTION and answer session and develop the innovative Whyline Debugging has long been a laborious task for software tool to prepare candidate questions and help to find developers [1], [2]. Despite the existence of various the answers by using both static and dynamic analysis automated debugging techniques, the practical debugging techniques. Nevertheless, developers may still encounter activities are mainly manual and interactive. It is difficult problems when using these techniques for real world to mechanically deal with diversified bugs, some of which debugging tasks. For example, they may want to try may be extremely tricky. Thus the fundamental tool in different techniques to find the fault more effectively. debugging is the human brain; the common debugging Then the problem is how they could use the outcomes process consists of several iterations of observing, making of different techniques. They may have to familiarize hypotheses, and testing the hypotheses [3]. themselves with various kinds of reports in the form of Most modern development environments provide com- tables of suspicious states, lists of faulty statements or prehensive utilities to aid debugging work. Among these some novel visualizations. Moreover, when the reports utilities, breakpoint is one of the most frequently used [4]. fail to indicate the faulty statements clearly, which is By using breakpoints developers can suspend the program often the case, developers probably have to switch to their execution and explore the program state to find clues to normal methods and make further effort to find the bugs. bugs. During the debugging process, however, developers In this case, they may need a seamless integration of the usually have to ask themselves a question: where to set the innovative techniques and the practical productivity tools. breakpoints? Setting breakpoints involves their observa- Thus it is helpful to improve the usability and the way tions, judgements and hypotheses on the current task and of combining automated debugging techniques to provide even experiences of similar situations. It is common that continuous support for debugging. a veteran sets a small number of breakpoints to reveal a In this paper, we propose a method to generate break- bug immediately, whereas a novice sets excessive useless points based on a synergy of existing fault localization breakpoints, but still fails to find the bug. Therefore, for a techniques. With regard to the typical situation of debug- developer, a set of well defined breakpoints presented in a familiar debugger may be a quite pleasant starting point 1http://www.eclipse.org/ © 2013 ACADEMY PUBLISHER doi:10.4304/jsw.8.3.603-616 604 JOURNAL OF SOFTWARE, VOL. 8, NO. 3, MARCH 2013 ging, where there are much fewer failing test cases than count spectra, how many times each basic block has been passing ones, we first use the nearest neighbor queries executed matters. Take the asymmetric Hamming distance method [6] to select a passing case that is the most (AHD) and binary coverage spectrum as an example. similar to the failing case (in terms of execution flow) and Binary coverage spectra are usually represented as binary compare them to find the suspicious basic blocks. Then vectors. Thus the Hamming distance between two runs we use backward dynamic slicing [13] to augment the f (failing run) and p (passing run) is defined as the report of the nearest neighbor queries in order to reveal number of positions at which the two representing binary the causes of the differences between the two execution vectors disagree. The asymmetric Hamming distance, flows. Line breakpoints are generated at the conditional which considers the non-symmetric difference f − p, is statements contained in the dynamic slices. At last we used to report features that are only present in the failing extract memory graphs at specific breakpoints, compare run f. A sample calculation is given in Table I. the graphs to identify the most interesting differences TABLE I. of program states, and generate breakpoint conditions AHD BETWEEN TWO RUNS, USING BINARY COVERAGE SPECTRA based on the state differences. The goal of our work is to automatically generate useful breakpoints to aid real sample Block 1 Block 2 Block 3 world debugging activities. We have performed a group Failing Run f 3 0 2 of objective experiments to show the effectiveness of Passing Run p 0 1 3 our technique in fault localization. In addition, we have Block Difference 1 0 0 Distance(f; p) = (1 + 0 + 0)=3 = 1=3 performed a user study to demonstrate the usefulness of our approach. When all the pairwise distances have been computed, An earlier version of the proposed approach has been the pair with the minimum distance value is selected and implemented and publicly demonstrated [14]. By com- compared. Finally, those basic blocks executed only in parison, this paper improves the step of breakpoint con- the failing run will be reported as suspicious. dition generation, making it more efficient and portable. Different from the tool demonstration paper [14], this B. Dynamic Program Slicing paper explains the key ideas with necessary background Program slicing was first introduced by Weiser [16] to (Section II) and a running example (Section III). Also, extract parts of program code corresponding to program this paper gives more detailed explanations on the con- behaviors of interest. Since then it has been widely siderations, strategies, algorithms, and trade-offs in our applied to program testing, debugging, understanding and approach (Section IV). In addition, a comprehensive eval- other maintenance activities. During program debugging it uation has been performed and the results are shown and can be used to reduce the amount of code developers need discussed extensively (Section VI). to inspect. In program slicing, a program is sliced with In summary, the main contributions of our work are: respect to a slicing criterion, hp; V i, where p is a specified • We propose the idea of automated breakpoint gen- program point and V is a set of variables of interest. eration by leveraging the power of fault localization The conventional program slicing is static, because it is techniques. This approach can be a viable way of performed based on static program dependencies and finds utilizing academic productions in practical debug- all the statements that might affect the slicing criterion. ging environments. Although being helpful to debugging, static program • We implement a prototype of our approach on top slicing often produces too large slices to reduce the de- of the Eclipse JDT platform and use it to perform velopers’ effort. In order to narrow down the search space objective experiments and case studies. The result further, Korel and Laski [13] proposed dynamic
Load more

Recommended publications
  • KDE 2.0 Development, Which Is Directly Supported
    23 8911 CH18 10/16/00 1:44 PM Page 401 The KDevelop IDE: The CHAPTER Integrated Development Environment for KDE by Ralf Nolden 18 IN THIS CHAPTER • General Issues 402 • Creating KDE 2.0 Applications 409 • Getting Started with the KDE 2.0 API 413 • The Classbrowser and Your Project 416 • The File Viewers—The Windows to Your Project Files 419 • The KDevelop Debugger 421 • KDevelop 2.0—A Preview 425 23 8911 CH18 10/16/00 1:44 PM Page 402 Developer Tools and Support 402 PART IV Although developing applications under UNIX systems can be a lot of fun, until now the pro- grammer was lacking a comfortable environment that takes away the usual standard activities that have to be done over and over in the process of programming. The KDevelop IDE closes this gap and makes it a joy to work within a complete, integrated development environment, combining the use of the GNU standard development tools such as the g++ compiler and the gdb debugger with the advantages of a GUI-based environment that automates all standard actions and allows the developer to concentrate on the work of writing software instead of managing command-line tools. It also offers direct and quick access to source files and docu- mentation. KDevelop primarily aims to provide the best means to rapidly set up and write KDE software; it also supports extended features such as GUI designing and translation in con- junction with other tools available especially for KDE development. The KDevelop IDE itself is published under the GNU Public License (GPL), like KDE, and is therefore publicly avail- able at no cost—including its source code—and it may be used both for free and for commer- cial development.
    [Show full text]
  • Using the GNU Debugger (Gdb) a Debugger Is a Very Useful Tool for Finding Bugs in a Program
    Using the GNU debugger (gdb) A debugger is a very useful tool for finding bugs in a program. You can interact with a program while it is running, start and stop it whenever, inspect the current values of variables and modify them, etc. If your program runs and crashes, it will produce a ‘core dump’. You can also use a debugger to look at the core dump and give you extra information about where the crash happened and what triggered it. Some debuggers (including recent versions of gdb) can also go backwards through your code: you run your code forwards in time to the point of an error, and then go backwards looking at the values of the key variables until you get to the start of the error. This can be slow but useful sometimes! To use a debugger effectively, you need to get the compiler to put extra ‘symbol’ information into the binary, otherwise all it will contain is machine code level – it is much more useful to have the actual variable names you used. To do this, you use: gfortran –g –O0 mycode.f90 –o mybinary where ‘-g’ is the compiler option to include extra symbols, -O0 is no optimization so the code is compiled exactly as written, and the output binary is called ’mybinary’. If the source files and executable file is in the same directory, then you can run the binary through the debugger by simply doing: gdb ./mybinary This will then put you into an interactive debugging session. Most commands can be shortened (eg ‘b’ instead of ‘break’) and pressing ‘enter’ will repeat the last command.
    [Show full text]
  • Intel® 64 and IA-32 Architectures Software Developer's Manual
    Intel® 64 and IA-32 Architectures Software Developer’s Manual Volume 3B: System Programming Guide, Part 2 NOTE: The Intel® 64 and IA-32 Architectures Software Developer's Manual consists of five volumes: Basic Architecture, Order Number 253665; Instruction Set Reference A-M, Order Number 253666; Instruction Set Reference N-Z, Order Number 253667; System Programming Guide, Part 1, Order Number 253668; System Programming Guide, Part 2, Order Number 253669. Refer to all five volumes when evaluating your design needs. Order Number: 253669-029US November 2008 INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL PRODUCTS. NO LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANT- ED BY THIS DOCUMENT. EXCEPT AS PROVIDED IN INTEL'S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, INTEL ASSUMES NO LIABILITY WHATSOEVER AND INTEL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY, RELATING TO SALE AND/OR USE OF INTEL PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. UNLESS OTHERWISE AGREED IN WRITING BY INTEL, THE INTEL PRODUCTS ARE NOT DESIGNED NOR IN- TENDED FOR ANY APPLICATION IN WHICH THE FAILURE OF THE INTEL PRODUCT COULD CREATE A SITUA- TION WHERE PERSONAL INJURY OR DEATH MAY OCCUR. Intel may make changes to specifications and product descriptions at any time, without notice. Designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "unde- fined." Intel reserves these for future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them.
    [Show full text]
  • Design of the RISC-V Instruction Set Architecture
    Design of the RISC-V Instruction Set Architecture Andrew Waterman Electrical Engineering and Computer Sciences University of California at Berkeley Technical Report No. UCB/EECS-2016-1 http://www.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-1.html January 3, 2016 Copyright © 2016, by the author(s). All rights reserved. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission. Design of the RISC-V Instruction Set Architecture by Andrew Shell Waterman A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Computer Science in the Graduate Division of the University of California, Berkeley Committee in charge: Professor David Patterson, Chair Professor Krste Asanovi´c Associate Professor Per-Olof Persson Spring 2016 Design of the RISC-V Instruction Set Architecture Copyright 2016 by Andrew Shell Waterman 1 Abstract Design of the RISC-V Instruction Set Architecture by Andrew Shell Waterman Doctor of Philosophy in Computer Science University of California, Berkeley Professor David Patterson, Chair The hardware-software interface, embodied in the instruction set architecture (ISA), is arguably the most important interface in a computer system. Yet, in contrast to nearly all other interfaces in a modern computer system, all commercially popular ISAs are proprietary.
    [Show full text]
  • ARM Debugger
    ARM Debugger TRACE32 Online Help TRACE32 Directory TRACE32 Index TRACE32 Documents ...................................................................................................................... ICD In-Circuit Debugger ................................................................................................................ Processor Architecture Manuals .............................................................................................. ARM/CORTEX/XSCALE ........................................................................................................... ARM Debugger ..................................................................................................................... 1 History ................................................................................................................................ 7 Warning .............................................................................................................................. 8 Introduction ....................................................................................................................... 9 Brief Overview of Documents for New Users 9 Demo and Start-up Scripts 10 Quick Start of the JTAG Debugger .................................................................................. 12 FAQ ..................................................................................................................................... 13 Troubleshooting ...............................................................................................................
    [Show full text]
  • Windows Powershell Best Practices Windows Powershell Best Practices
    Windows PowerShell Best Practices Windows PowerShell Best Practices Expert recommendations, pragmatically applied Automate system administration using Windows PowerShell best practices—and optimize your operational efficiency. With this About the Author practical guide, Windows PowerShell expert and instructor Ed Ed Wilson, MCSE, CISSP, is a well-known Wilson delivers field-tested tips, real-world examples, and candid scripting expert and author of “Hey Windows Scripting Guy!”—one of the most popular advice culled from administrators across a range of business and blogs on Microsoft TechNet. He’s written technical scenarios. If you’re an IT professional with Windows several books on Windows scripting PowerShell experience, this book is ideal. for Microsoft Press, including Windows PowerShell 2.0 Best Practices and Windows PowerShell Scripting Guide. Discover how to: PowerShell • Use Windows PowerShell to automate Active Directory tasks • Explore available WMI classes and methods with CIM cmdlets • Identify and track scripting opportunities to avoid duplication • Use functions to encapsulate business logic and reuse code • Design your script’s best input method and output destination • Test scripts by checking their syntax and performance • Choose the most suitable method for running remote commands • Manage software services with Desired State Configuration Wilson BEST PRACTICES microsoft.com/mspress ISBN 978-0-7356-6649-8 U.S.A. $59.99 55999 Canada $68.99 [Recommended] 9 780735 666498 Operating Systems/Windows Server Celebrating 30 years! Ed Wilson 666498_Win_PowerShell_Best_Practices.indd 1 4/11/14 10:30 AM Windows PowerShell Best Practices Ed Wilson 666498_book.indb 1 12/20/13 10:50 AM Published with the authorization of Microsoft Corporation by: O’Reilly Media, Inc.
    [Show full text]
  • Debugger User's Guide
    DEBUGGER USER'S GUIDE Version 2018 TABLE OF CONTENTS Preface............................................................................................................ xii Intended Audience............................................................................................ xii Documentation.................................................................................................xii Compatibility and Conformance to Standards............................................................xii Organization................................................................................................... xiii Conventions.................................................................................................... xiv Terminology.....................................................................................................xv Related Publications.......................................................................................... xv Chapter 1. Getting Started.....................................................................................1 1.1. Definition of Terms.......................................................................................1 1.2. Building Applications for Debug........................................................................2 1.2.1. Debugging Optimized Code........................................................................ 2 1.2.2. Building for Debug on Windows...................................................................2 1.3. User Interfaces...........................................................................................
    [Show full text]
  • Kdevelop Handbook
    KDevelop Handbook This documentation was converted from the KDE UserBase KDevelop4/Manual page. KDevelop Handbook 2 Contents 1 What is KDevelop?6 2 Sessions and projects: The basics of KDevelop8 2.1 Terminology . .8 2.2 Setting up a session and importing an existing project . .9 2.2.1 Option 1: Importing a project from a version control system server . .9 2.2.2 Option 2: Importing a project that is already on your hard drive . 10 2.3 Setting up an application as a second project . 10 2.4 Creating projects from scratch . 10 3 Working with source code 12 3.1 Tools and views . 12 3.2 Exploring source code . 14 3.2.1 Local information . 14 3.2.2 File scope information . 16 3.2.3 Project and session scope information . 17 3.2.4 Rainbow color highlighting explained . 19 3.3 Navigating in source code . 19 3.3.1 Local navigation . 19 3.3.2 File scope navigation and outline mode . 20 3.3.3 Project and session scope navigation: Semantic navigation . 21 3.4 Writing source code . 25 3.4.1 Auto-completion . 25 3.4.2 Adding new classes and implementing member functions . 27 3.4.3 Documenting declarations . 31 3.4.4 Renaming variables, functions and classes . 34 3.4.5 Code snippets . 35 3.5 Modes and working sets . 37 3.6 Some useful keyboard shortcuts . 39 KDevelop Handbook 4 Code generation with templates 41 4.1 Creating a new class . 41 4.2 Creating a new unit test . 43 4.3 Other files .
    [Show full text]
  • The RISC-V Instruction Set Manual Volume I: User-Level ISA Document Version 2.2
    The RISC-V Instruction Set Manual Volume I: User-Level ISA Document Version 2.2 Editors: Andrew Waterman1, Krste Asanovi´c1;2 1SiFive Inc., 2CS Division, EECS Department, University of California, Berkeley [email protected], [email protected] May 7, 2017 Contributors to all versions of the spec in alphabetical order (please contact editors to suggest corrections): Krste Asanovi´c,Rimas Aviˇzienis,Jacob Bachmeyer, Christopher F. Batten, Allen J. Baum, Alex Bradbury, Scott Beamer, Preston Briggs, Christopher Celio, David Chisnall, Paul Clayton, Palmer Dabbelt, Stefan Freudenberger, Jan Gray, Michael Hamburg, John Hauser, David Horner, Olof Johansson, Ben Keller, Yunsup Lee, Joseph Myers, Rishiyur Nikhil, Stefan O'Rear, Albert Ou, John Ousterhout, David Patterson, Colin Schmidt, Michael Taylor, Wesley Terpstra, Matt Thomas, Tommy Thorn, Ray VanDeWalker, Megan Wachs, Andrew Waterman, Robert Wat- son, and Reinoud Zandijk. This document is released under a Creative Commons Attribution 4.0 International License. This document is a derivative of \The RISC-V Instruction Set Manual, Volume I: User-Level ISA Version 2.1" released under the following license: c 2010{2017 Andrew Waterman, Yunsup Lee, David Patterson, Krste Asanovi´c. Creative Commons Attribution 4.0 International License. Please cite as: \The RISC-V Instruction Set Manual, Volume I: User-Level ISA, Document Version 2.2", Editors Andrew Waterman and Krste Asanovi´c,RISC-V Foundation, May 2017. Preface This is version 2.2 of the document describing the RISC-V user-level architecture. The document contains the following versions of the RISC-V ISA modules: Base Version Frozen? RV32I 2.0 Y RV32E 1.9 N RV64I 2.0 Y RV128I 1.7 N Extension Version Frozen? M 2.0 Y A 2.0 Y F 2.0 Y D 2.0 Y Q 2.0 Y L 0.0 N C 2.0 Y B 0.0 N J 0.0 N T 0.0 N P 0.1 N V 0.2 N N 1.1 N To date, no parts of the standard have been officially ratified by the RISC-V Foundation, but the components labeled \frozen" above are not expected to change during the ratification process beyond resolving ambiguities and holes in the specification.
    [Show full text]
  • IDE, a Software Environment You Can Use to Develop Your C/C++ Programs
    The University of CMSC 15200 ± Introduction to Computer Science 2 Chicago Summer Quarter 2005 Department of Lab #2 (08/01/2005) Computer Science Name: Student ID: Lab Instructor: Borja Sotomayor Do not write in this area 1 2 3 TOTAL Maximum possible points: 30 One of the goals of this lab is to introduce the Eclipse IDE, a software environment you can use to develop your C/C++ programs. We provide some basic instructions on how to write a program with Eclipse, and how to use Eclipse's debugging features. More complete documentation can be found in Eclipse's official website: http://www.eclipse.org/ http://www.eclipse.org/documentation/ http://help.eclipse.org/ IDE: Integrated Development Environment An IDE, or Integrated Development Environment, provides an environment that integrates all the tools necessary to develop a piece of software. IDEs typically include a text editor, a compiler, a debugger, and other tools to improve the productivity of the programmer. For example, many IDEs include tools that allow us to easily create graphical interfaces for our own applications (“UI designers”) The user can interact with all these tools (editor, compiler, etc.) using an interface which generally (but not always) will be an easy-to-use graphical interface. In fact, the main advantage of using an IDE is that the programmer can do all his work from a single interface, instead of having to constantly switch between different tools. The following are some popular IDEs: ➢ Free / Open source (UNIX/Linux) ● Eclipse (Multi-platform, Java, C/C++, other
    [Show full text]
  • The Design of a Debugger Unit for a RISC Processor Core
    Rochester Institute of Technology RIT Scholar Works Theses 3-2018 The Design of a Debugger Unit for a RISC Processor Core Nikhil Velguenkar [email protected] Follow this and additional works at: https://scholarworks.rit.edu/theses Recommended Citation Velguenkar, Nikhil, "The Design of a Debugger Unit for a RISC Processor Core" (2018). Thesis. Rochester Institute of Technology. Accessed from This Master's Project is brought to you for free and open access by RIT Scholar Works. It has been accepted for inclusion in Theses by an authorized administrator of RIT Scholar Works. For more information, please contact [email protected]. The Design of a Debugger Unit for a RISC Processor Core by Nikhil Velguenkar Graduate Paper Submitted in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering Approved by: Mr. Mark A. Indovina, Lecturer Graduate Research Advisor, Department of Electrical and Microelectronic Engineering Dr. Sohail A. Dianat, Professor Department Head, Department of Electrical and Microelectronic Engineering Department of Electrical and Microelectronic Engineering Kate Gleason College of Engineering Rochester Institute of Technology Rochester, New York March 2018 To my family and friends, for all of their endless love, support, and encouragement throughout my career at Rochester Institute of Technology Abstract Recently, there has been a significant increase in design complexity for Embedded Sys- tems often referred to as Hardware Software Co-Design. Complexity in design is due to both hardware and firmware closely coupled together in-order to achieve features forlow power, high performance and low area. Due to these demands, embedded systems consist of multiple interconnected hardware IPs with complex firmware algorithms running on the device.
    [Show full text]
  • Virtual Breakpoints for X86/64
    Virtual Breakpoints for x86/64 Gregory Price1∗y August 22, 2019 Abstract Debuggers [1] and other instrumentation tools [3][4][7][11] are becoming increasingly complex as Efficient, reliable trapping of execution in a pro- malware deploys equally complex anti-analysis gram at the desired location is a linchpin tech- techniques. Many techniques require special mem- nique for dynamic malware analysis. The pro- ory allocators, compilers, or complex systems to gression of debuggers and malware is akin to a control the \view" of memory [10, 2]. In some game of cat and mouse - each are constantly in cases, the efficiency or robustness of these tech- a state of trying to thwart one another. At the niques rely on architecture-level quirks that are core of most efficient debuggers today is a com- more of a happy accident, rather than intentional bination of virtual machines and traditional bi- design. For example, SPIDER breakpoints [2] nary modification breakpoints (int3). In this pa- rely on a caching quirk of Intel CPU's to remain per, we present a design for Virtual Breakpoints efficient, and many dynamic binary instrumenta- | a modification to the x86 MMU which brings tion systems [10] are a mess of trampolines and breakpoint management into hardware alongside runtime hooking. page tables. In this paper we demonstrate the Despite the growing complexity, all of these fundamental abstraction failures of current trap- systems must trade between efficiency, reliabil- ping methods, and design a new mechanism from ity, and transparency [4]. If a trapping mech- the hardware up. This design incorporates lessons anism introduces significant overhead, analysis learned from 50 years of virtualization and de- becomes tedious.
    [Show full text]