Why are stack overflows still a problem?

Question

This question is mystifying me for years and considering this site\'s name, this is the place to ask.

Why do we, programmers, still have this StackOverflow

Answer 1

Stacks are resized dynamically - or to be precise, grown dynamically. You get an overflow when a stack cannot grow any further, which is not to say it exhausted the address space, but rather grown to conflict with a portion of memory used to other purposes (e.g., a process heap).

Maybe you mean that stacks cannot be moved dynamically? The root of that is probably that stacks are intimately coupled to the hardware. CPUs have registers and piles of logic dedicated to thread stack management (esp, ebp, call/return/enter/leave instructions on x86). If your language is compiled (or even jitted) you're bound to the hardware mechanism and cannot move stacks around.

This hardware 'limitation' is probably here to stay. Re-basing a thread stack during thread execution seems far from a reasonable demand from a hardware platform (and the added complexity would badly hamper all executed code on such an imaginary CPU, even compiled). One can picture a completely virtualized environment where this limitation does not hold, but since such code couldn't be jitted - it would be unbearably slow. Not a chance you could do anything interactive with it.