Return failure from PTE sync if master mapping does not exist.

udosteinberg · Aug 9, 2013 · 6bc45a3 · 6bc45a3
1 parent 41db102
commit 6bc45a3
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/src/hpt.cpp b/src/hpt.cpp
@@ -4,7 +4,7 @@
  * Copyright (C) 2009-2011 Udo Steinberg <udo@hypervisor.org>
  * Economic rights: Technische Universitaet Dresden (Germany)
  *
- * Copyright (C) 2012 Udo Steinberg, Intel Corporation.
+ * Copyright (C) 2012-2013 Udo Steinberg, Intel Corporation.
  *
  * This file is part of the NOVA microhypervisor.
  *
@@ -26,9 +26,11 @@ bool Hpt::sync_from (Hpt src, mword v, mword o)
 {
     mword l = (bit_scan_reverse (v ^ o) - PAGE_BITS) / bpl();
 
-    Hpt *s = static_cast<Hpt *>(src.walk (v, l, false)), *d = static_cast<Hpt *>(walk (v, l));
+    Hpt *s = static_cast<Hpt *>(src.walk (v, l, false));
+    if (!s)
+        return false;
 
-    assert (s);
+    Hpt *d = static_cast<Hpt *>(walk (v, l));
     assert (d);
 
     if (d->val == s->val)