Oh yeah, I didn't think of that. I wonder if you could write a signal handler carefully to not allocate any memory, stack or otherwise, or is some return address or an internal structure being allocated transparently...
Just trying to allocate stack space for the signal handler may cause the stack to spill into a new page. That is absolutely out of anybody's control. And if that new page cannot be provided, it's game over.
Makes sense. I was thinking that maybe signal handlers could use the regular stack of the thread, but that would of course make everything fall down if the "real" code would write to the stack before updating the stack pointer.
