Fix for issue 341. In the stub for instanceof, we could try to read

an object's map before we were sure it was a heap object.
Review URL: http://codereview.chromium.org/115236

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1914 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/ia32/codegen-ia32.cc

@@ -7186,7 +7186,7 @@ void InstanceofStub::Generate(MacroAssembler* masm) {
   __ j(zero, &slow, not_taken);
 
   // Check that the left hand is a JS object.
-  __ mov(eax, FieldOperand(eax, HeapObject::kMapOffset));  // ebx - object map
+  __ mov(eax, FieldOperand(eax, HeapObject::kMapOffset));  // eax - object map
   __ movzx_b(ecx, FieldOperand(eax, Map::kInstanceTypeOffset));  // ecx - type
   __ cmp(ecx, FIRST_JS_OBJECT_TYPE);
   __ j(less, &slow, not_taken);
@@ -7198,6 +7198,8 @@ void InstanceofStub::Generate(MacroAssembler* masm) {
   __ TryGetFunctionPrototype(edx, ebx, ecx, &slow);
 
   // Check that the function prototype is a JS object.
+  __ test(ebx, Immediate(kSmiTagMask));
+  __ j(zero, &slow, not_taken);
   __ mov(ecx, FieldOperand(ebx, HeapObject::kMapOffset));
   __ movzx_b(ecx, FieldOperand(ecx, Map::kInstanceTypeOffset));
   __ cmp(ecx, FIRST_JS_OBJECT_TYPE);

test/mjsunit/regress/regress-341.js

+// Copyright 2009 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Should not crash.
+// See http://code.google.com/p/v8/issues/detail?id=341
+
+function F() {}
+
+F.prototype = 1;
+var o = {};
+
+assertThrows("o instanceof F");