Attempt to raise Null exception in disassembled code in Visual Studio

Question

I have a .NET 3.5 disassembled code, and I'm attempting to cause a NullReferenceException, to try and mimic a behavior I see in some dumps.

For example, I can see the following command:

mov         byte ptr [rdi],0 

I assume that by setting rdi<-0, I could cause dereference to address 0x0.

However, I'm unable to edit any register value.

In MSDN, they claim 'Registers' window have the power to edit registers:

https://msdn.microsoft.com/en-us/library/9dfstwbe.aspx

But this doesn't work to me in Visual Studio 2012.

Any help or other workaround?

Answer 1

It is possible only while debugging C/C++ code. Tested it on a mixed solution C# + C++, C#-side it was readonly, C++ side I could overwrite the text (note that the window "appearance" doesn't change... it is always something like the notepad)

When debugging a C/C++ app, you can even write EAX (or eax, it isn't case sensitive) in the watch window and you can edit it from there.