Is it possible to predict a stack overflow in C on Linux?

Question

There are certain conditions that can cause stack overflows on an x86 Linux system:

• struct my_big_object[HUGE_NUMBER] on the stack. Walking throu

Answer 1

alloca() is going to return NULL on failure, I believe the behavior of alloca(0) is undefined and platform variant. If you check for that prior to do_something(), you should never be hit with a SEGV.

I have a couple of questions:

1. Why, oh why, do you need something that big on the stack? The default size on most systems is 8M, that's still too small?
2. If the function calling alloca() blocks, would protecting the same amount of heap via mlock() / mlockall() guarantee close to the same access performance (i.e. "Don't swap me, bro!") over time? If your using a more aggressive 'rt' scheduler, its recommended to call those anyway.

The question is interesting but raises an eyebrow. It raises the needle on my square-peg-round-hole-o-meter.