Question

I would like to make a checksum of the current stack in the main, in order to check if it has been altered between two points.

For example:

int main(void) {
    ...
    stack_checksum();

    ... process ...

    if(stack_checksum() != ...)
        altered.
}

How can I grab the base stack address and the current address of the stack’s top ?

EDIT:
With @Miroslav Bajtoš help, step for approach:

• Put local variable in a structure
• Check backtrace return array

Answer 1

It depends on which compiler/implementation of standard library you are using.

For gcc (or any other compiler that uses glibc), you can use backtrace() functions in execinfo.h – see these answers for more details: How to generate a stacktrace when my gcc C++ app crashes and How to get more detailed backtrace

For Microsoft compiler, you can use StackWalk64() function, see this article for more details: Walking-the-callstack. There was also a similar quesion asked here on StackOverflow: StackWalk64 on Windows – Get symbol name

Computing checksum should be easy once you can walk the stack.