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What a weirdo: How the /analyze switch changes its behavior depending on its environment

In Visual Studio 2005 Team System (VSTS), the “ultimate” SKU of Visual Studio 2005, Microsoft introduced the /analyze compiler switch. When the /analyze switch is used, the cl compiler not only does its regular checks, but performs a much more thorough static code analysis. While /analyze is very useful indeed, it was only available in the top SKU – the Standard and Professional versions of Visual Studio lacked support for this compiler switch (this has changed by now, Professional now also supports this feature).…

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Launched ntrace.org

Having given my presentation on NTrace today at the WCRE in Lille/France, I have also opened ntrace.org to the public. NTrace, in case you have missed my previous posts, is a dynamic function boundary tracing system for Windows/x86 I initially developed as part of my Master’s thesis that is capable of performing DTrace-like tracing of both user and kernel mode components. On the NTrace page, you will now find the paper itself as being published as part of the WCRE proceedings (mind the copyright notice, please) along with two screencasts: One showing how NTrace can be used to trace kernel mode components such as NTFS, and one demonstrating NTrace for user mode tracing.…

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I'll be at WCRE 2009 presenting NTrace

Next week, the 16th Working Conference on Reverse Engineering (WCRE) will be held in Lille, France. I will be there presenting NTrace: Function Boundary Tracing for Windows on IA-32. NTrace is a dynamic function boundary tracing toolkit for IA-32/x86 that can be used to trace both kernel and user mode Windows components – examples for components that can be traced include the kernel itself (ntoskrnl), drivers like NTFS as well as user mode components such as kernel32, shell32 or even explorer.…

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More Context Menu Handlers for Everyday Use

Although Windows Explorer may actually not be the brightest spot of Windows, it is still, for most users, among the most often used pograms. Customizing it to speed up certain tasks is thus a natural desire. A while ago, I wrote about how to extend the context menu by new commands that allow MSI packages to be installed/uninstalled with logfiles being created. The registry entries I used were: Windows Registry Editor Version 5.…

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Thread 0:0 is special

Thread IDs uniquely identify a thread – this certainly holds for user mode threads and should also hold for kernel mode threads. But there is one kind of thread where the ID does not uniquely identify a KTHREAD – the Idle thread. On a uniprocessor system, there is only one Idle thread and this idle thread will have the thread ID 0 (in process 0). On a multiprocessor system, however, Windows creates one Idle thread per CPU.…

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Reaching beyond the top of the stack -- illegal or just bad style?

The stack pointer, esp on i386, denotes the top of the stack. All memory below the stack pointer (i.e. higher addresses) is occupied by parameters, variables and return addresses; memory above the stack pointer must be assumed to contain garbage. When programming in assembly, it is equally easy to use memory below and above the stack pointer. Reading from or writing to addresses beyond the top of the stack is unusual and under normal circumstances, there is little reason to do so.…

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Fun with low level SEH

Most code that uses Structured Exception Handling does this with the help of the compiler, e.g. by using try/except/__finally. Still, it is possible to do everything by hand, i.e. to provide your own exception handlers and set up the exception registration records manually. However, as this entire topic is not documented very well, doing so opens room for all kind of surprises… Although more than 10 years old, the best article on this topic still seems to be Matt Pirtrek’s A Crash Course on the Depths of Win32™ Structured Exception Handling, which I assume you have read.…

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