const GUARD_PAGES: usize = 1;
let guard = guardaddr..guardaddr + GUARD_PAGES * page_size;
Some(guard)
+ } else if cfg!(target_os = "openbsd") {
+ // OpenBSD stack already includes a guard page, and stack is
+ // immutable.
+ //
+ // We'll just note where we expect rlimit to start
+ // faulting, so our handler can report "stack overflow", and
+ // trust that the kernel's own stack guard will work.
+ let stackptr = get_stack_start_aligned()?;
+ let stackaddr = stackptr.addr();
+ Some(stackaddr - page_size..stackaddr)
} else {
// Reallocate the last page of the stack.
// This ensures SIGBUS will be raised on