Archive for December 1st, 2008

Crash Dump Analysis Patterns (Part 78a)

Monday, December 1st, 2008

This December starts with easy and obvious patterns that I forgot to write about. Integer division by zero is one of the most frequent exceptions. It is easily recognizable in process crash dumps by the processor instruction that caused this exception type (DIV or IDIV):

FAULTING_IP:
DLL!FindHighestID+278
1b2713c4 f775e4 div dword ptr [ebp-0×1c]

EXCEPTION_RECORD: ffffffff -- (.exr ffffffffffffffff)
ExceptionAddress: 1b2713c4 (DLL!FindHighestID+0x00000278)
ExceptionCode: c0000094 (Integer divide-by-zero)
ExceptionFlags: 00000000
NumberParameters: 0

or

FAULTING_IP:
Application+263d8
004263d8 f7fe idiv eax,esi

EXCEPTION_RECORD: ffffffff -- (.exr 0xffffffffffffffff)
ExceptionAddress: 004263d8 (Application+0x000263d8)
ExceptionCode: c0000094 (Integer divide-by-zero)
ExceptionFlags: 00000000
NumberParameters: 0

ERROR_CODE: (NTSTATUS) 0xc0000094 - {EXCEPTION} Integer division by zero.

- Dmitry Vostokov @ DumpAnalysis.org -

Posted in Crash Dump Analysis, Crash Dump Patterns, Debugging | 1 Comment »

The Deep Meaning of Astrology

Monday, December 1st, 2008

A bit of digression on the first winter day in Ireland. What does it mean to be meanigful as astrology? It is meaningful as Tr O(Log y):

AsTrOLogy ↔ As Tr O(Log y) ↔ As O(Log y) ↔ bound (or dominated in case of small-o notation) by Log y after some y >= y0 or bound (or dominated in case of small-o notation) by -logy. So Astrology is bounded and dominated by Y (Why?) lowered in magnitude by Log. Bounded and dominated by the this ultimate question…

Tr is trace operation in linear algebra. Tr (a number) = a number by definition of a 1×1 matrix
O is Big O notation

- Dmitry Vostokov @ DumpAnalysis.org -

Posted in Build Date Astrology, Software Astrology | 2 Comments »