--- old/src/cpu/zero/vm/stack_zero.inline.hpp	2014-11-14 13:50:23.162677984 +0100
+++ new/src/cpu/zero/vm/stack_zero.inline.hpp	2014-11-14 13:50:23.059676930 +0100
@@ -47,10 +47,11 @@
 // This method returns the amount of ABI stack available for us
 // to use under normal circumstances.  Note that the returned
 // value can be negative.
-inline int ZeroStack::abi_stack_available(Thread *thread) const {
-  int stack_used = thread->stack_base() - (address) &stack_used;
-  int stack_free = thread->stack_size() - stack_used;
-  return stack_free - shadow_pages_size();
+inline ssize_t ZeroStack::abi_stack_available(Thread *thread) const {
+  ssize_t stack_used = thread->stack_base() - (address) &stack_used
+    + (StackYellowPages+StackRedPages+StackShadowPages) * os::vm_page_size();
+  ssize_t stack_free = thread->stack_size() - stack_used;
+  return stack_free;
 }
 
 #endif // CPU_ZERO_VM_STACK_ZERO_INLINE_HPP