Check out the new USENIX Web site.

USENIX Home . About USENIX . Events . membership . Publications . Students
USENIX 2005 Annual Technical Conference, General Track — Abstract

Pp. 1–15 of the Proceedings

Awarded General Track Best Paper!

Debugging Operating Systems with Time-Traveling Virtual Machines

Samuel T. King, George W. Dunlap, and Peter M. Chen, University of Michigan

Abstract

Operating systems are difficult to debug with traditional cyclic debugging. They are non-deterministic; they run for long periods of time; they interact directly with hardware devices; and their state is easily perturbed by the act of debugging. This paper describes a time-traveling virtual machine that overcomes many of the difficulties associated with debugging operating systems. Time travel enables a programmer to navigate backward and forward arbitrarily through the execution history of a particular run and to replay arbitrary segments of the past execution. We integrate time travel into a general-purpose debugger to enable a programmer to debug an OS in reverse, implementing commands such as reverse breakpoint, reverse watchpoint, and reverse single step. The space and time overheads needed to support time travel are reasonable for debugging, and movements in time are fast enough to support interactive debugging. We demonstrate the value of our time-traveling virtual machine by using it to understand and fix several OS bugs that are difficult to find with standard debugging tools. Reverse debugging is especially helpful in finding bugs that are fragile due to non-determinism, bugs in device drivers, bugs that require long runs to trigger, bugs that corrupt the stack, and bugs that are detected after the relevant stack frame is popped.
  • View the full text of this paper in HTML and PDF.
    The Proceedings are published as a collective work, © 2005 by the USENIX Association. All Rights Reserved. Rights to individual papers remain with the author or the author's employer. Permission is granted for the noncommercial reproduction of the complete work for educational or research purposes. USENIX acknowledges all trademarks within this paper.

  • If you need the latest Adobe Acrobat Reader, you can download it from Adobe's site.
To become a USENIX Member, please see our Membership Information.

?Need help? Use our Contacts page.

Last changed: 12 April 2005 aw
Technical Program
USENIX '05 Home
USENIX home