--- a/hotspot/src/os/windows/vm/os_windows.cpp	Wed Sep 07 15:21:45 2016 +0200
+++ b/hotspot/src/os/windows/vm/os_windows.cpp	Wed Sep 07 12:52:20 2016 -0400
@@ -2504,13 +2504,15 @@
   // It write enables the page immediately after protecting it
   // so just return.
   if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
-    JavaThread* thread = (JavaThread*) t;
-    PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
-    address addr = (address) exceptionRecord->ExceptionInformation[1];
-    if (os::is_memory_serialize_page(thread, addr)) {
-      // Block current thread until the memory serialize page permission restored.
-      os::block_on_serialize_page_trap();
-      return EXCEPTION_CONTINUE_EXECUTION;
+    if (t != NULL && t->is_Java_thread()) {
+      JavaThread* thread = (JavaThread*) t;
+      PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
+      address addr = (address) exceptionRecord->ExceptionInformation[1];
+      if (os::is_memory_serialize_page(thread, addr)) {
+        // Block current thread until the memory serialize page permission restored.
+        os::block_on_serialize_page_trap();
+        return EXCEPTION_CONTINUE_EXECUTION;
+      }
     }
   }
 
@@ -2564,7 +2566,7 @@
       }
 #endif
       if (thread->stack_guards_enabled()) {
-        if (_thread_in_Java) {
+        if (in_java) {
           frame fr;
           PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
           address addr = (address) exceptionRecord->ExceptionInformation[1];
@@ -2576,6 +2578,7 @@
         // Yellow zone violation.  The o/s has unprotected the first yellow
         // zone page for us.  Note:  must call disable_stack_yellow_zone to
         // update the enabled status, even if the zone contains only one page.
+        assert(thread->thread_state() != _thread_in_vm, "Undersized StackShadowPages");
         thread->disable_stack_yellow_reserved_zone();
         // If not in java code, return and hope for the best.
         return in_java