How to get address of base stack pointer

Question

I am in the process of porting an application from x86 to x64. I am using Visual Studio 2009; most of the code is C++ and some portions are plain C. The __asm keyword is not

Answer 1

You can use the _AddressOfReturnAddress() intrinsic to determine a location in the current frame pointer, assuming it hasn't been completely optimized away. I'm assuming that the compiler will prevent that function from optimizing away the frame pointer if you explicitly refer to it. Or, if you only use a single thread, you can use the IMAGE_NT_HEADER.OptionalHeader.SizeOfStackReserve and IMAGE_NT_HEADER.OptionalHeader.SizeOfStackCommit to determine the main thread's stack size. See this for how to access the IMAGE_NT_HEADER for the current image.

I would also recommend against using IsBadWritePtr to determine the end of the stack. At the very least you will probably cause the stack to grow until you hit the reserve, as you'll trip a guard page. If you really want to find the current size of the stack, use VirtualQuery with the address you are checking.

And if the original use is to walk the stack, you can use StackWalk64 for that.