Conclusion

Congratulations!

Congratulations on completing this course! We hope your new debugging skills help you with the next core dump you encounter and give you an excellent foundational grasp of what’s possible with core dump analysis. We hope it got you thinking about the pattern-oriented diagnostic approach.

Key highlights

Here are some of the key highlights of this course:

• We learned about virtual memory setup in Linux and the storage of memory dumps and explored various dump types such as process, kernel, and fiber bundle memory dumps.

• We developed an understanding of thread stacks and traces, enabling us to analyze and debug thread-related issues.

• We learned how to identify and handle access violation exceptions and runtime exceptions.

• We learned how to collect core dumps in multiple ways.

• We reviewed basic x64 disassembly, including the role of various CPU registers, memory addressing, and various instructions for memory manipulation, flow control, function calls, and how to do stack trace reconstruction.

• We learned how to use GDB, including loading core dump files, printing stack traces, retrieving information, examining memory contents, disassembling functions, and the use of some other frequently used commands.

• We detected issues related to analyzing multi-threaded applications using GDB, enabling us to navigate stack traces, disassemble functions, and manage threads within a multi-threaded environment.

• We gained expertise in identifying NULL pointer problems that arise both due to data and code.

• We identified issues arising due to spiking threads, enabling analysis of non-waiting threads and identification of infinite loops.

• We identified issues arising due to dynamic memory corruption, enabling the identification of heap corruption and memory access violations.

• We identified issues that arose due to dividing by zero, enabling the detection of resulting undefined behavior in core dumps.

• We studied how to make use of execution residues and coincidental symbolic information and how to identify C++ exceptions, both handled and unhandled, enabling effective detection and resolution of complex issues.

• We learned how to do critical region analysis, enabling us to identify and examine code regions sandwiched by contending function calls, leading to the identification of synchronization issues.

• We detected issues related to deadlocks and synchronization wait chains, enabling us to identify these problems by analyzing core dumps, thread stacks, specific threads, and disassembled processes.

• We detected issues related to memory dumping for post-processing, function and variable list retrieval, symbol file loading, and variable inspection.

• We learned how to navigate both normal and problematic kernel dumps, identify issues with kernel threads and spiking kernel threads, and identify kernel stack overflows and boundaries using the crash utility, enabling us to analyze and debug kernel-related issues effectively.