# HG changeset patch
# User johnc
# Date 1271371975 25200
# Node ID 5dbd9300cf9cfe267ab776b1de45e971064d1824
# Parent  7666957bc44d75c33b99ceec104aa04582acc303
6943926: G1: Integer overflow during heap region verification
Summary: The expression that calculates the live bytes for a heap region can overflow for a suitably large humongous region/object. Cache the object size in a suitably sized local variable so that the expression is converted to a wider type.
Reviewed-by: tonyp, jmasa, iveresov, apetrusenko

diff -r 7666957bc44d -r 5dbd9300cf9c src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Tue Mar 30 15:43:03 2010 -0400
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Thu Apr 15 15:52:55 2010 -0700
@@ -2194,8 +2194,10 @@
     assert(o != NULL, "Huh?");
     if (!_g1h->is_obj_dead_cond(o, _use_prev_marking)) {
       o->oop_iterate(&isLive);
-      if (!_hr->obj_allocated_since_prev_marking(o))
-        _live_bytes += (o->size() * HeapWordSize);
+      if (!_hr->obj_allocated_since_prev_marking(o)) {
+        size_t obj_size = o->size();    // Make sure we don't overflow
+        _live_bytes += (obj_size * HeapWordSize);
+      }
     }
   }
   size_t live_bytes() { return _live_bytes; }