Breakpad Crash Reporting for Mozilla

  • January 24, 2007
    • Links updated February 14, 2007
  • Mozilla HQ
  • Mark Mentovai
  • Brian Ryner

What is a crash reporter?

  • Enables developers to analyze crashes that occur in the wild
  • Produces stack backtraces that help identify how a program failed
  • Offers higher-level data aggregation (topcrashes, MTBF statistics)


  • Talkback is proprietary and unmaintained
  • Smaller open-source projects have few options
  • Larger projects need flexibility and scalability

Design Options

  • Stackwalking done on client
    • Apple CrashReporter
    • GNOME BugBuddy
  • Client sends memory dump
    • Talkback
    • Windows Error Reporting
    • Breakpad


  • Provide libraries around which systems can be based
  • Open-source
  • Cross-platform
    • Mac OS X x86, PowerPC
    • Linux x86
    • Windows x86
  • No requirement to distribute symbols

Client Libraries

  • Exception handler installed at application startup
    • Spawns a separate thread
  • Minidump file written at crash time
    • Format used by Windows debuggers
  • Separate application invoked to send
    • HTTPS POST, can include additional parameters


  • Cross-platform symbol file format
  • Contents
    • Function names
    • Source file names and line numbers
    • Windows: Frame pointer omission data
    • Future: parameters and local variables
  • Symbol conversion methods


  • Examines minidump file and invokes stackwalker
  • Symbol files requested from a SymbolSupplier
  • Produces stack trace
  • Output may be placed where convenient


More Information