+#include <thread.h>
+#ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
+#define CONTROL_STACK_GUARD_PAGE(th) \
+ ((os_vm_address_t)(th->control_stack_start))
+#define CONTROL_STACK_RETURN_GUARD_PAGE(th) \
+ (CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size)
+#else
+#define CONTROL_STACK_GUARD_PAGE(th) \
+ (((os_vm_address_t)(th->control_stack_end)) - os_vm_page_size)
+#define CONTROL_STACK_RETURN_GUARD_PAGE(th) \
+ (CONTROL_STACK_GUARD_PAGE(th) - os_vm_page_size)
+#endif
+