Add array bound checks to code generated for SwapElements. This fixes a bug that lead to a segfault when an array was modified while it was sorted.

Review URL: http://codereview.chromium.org/5686006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6020 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/codegen-arm.cc

@@ -5592,6 +5592,12 @@ void CodeGenerator::GenerateSwapElements(ZoneList<Expression*>* args) {
   __ tst(tmp2, Operand(kSmiTagMask));
   deferred->Branch(nz);
 
+  // Check that both indices are valid.
+  __ ldr(tmp2, FieldMemOperand(object, JSArray::kLengthOffset));
+  __ cmp(tmp2, index1);
+  __ cmp(tmp2, index2, hi);
+  deferred->Branch(ls);
+
   // Bring the offsets into the fixed array in tmp1 into index1 and
   // index2.
   __ mov(tmp2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));

src/ia32/codegen-ia32.cc

@@ -7676,6 +7676,13 @@ void CodeGenerator::GenerateSwapElements(ZoneList<Expression*>* args) {
   __ test(tmp2.reg(), Immediate(kSmiTagMask));
   deferred->Branch(not_zero);
 
+  // Check that both indices are valid.
+  __ mov(tmp2.reg(), FieldOperand(object.reg(), JSArray::kLengthOffset));
+  __ cmp(tmp2.reg(), Operand(index1.reg()));
+  deferred->Branch(below_equal);
+  __ cmp(tmp2.reg(), Operand(index2.reg()));
+  deferred->Branch(below_equal);
+
   // Bring addresses into index1 and index2.
   __ lea(index1.reg(), FixedArrayElementOperand(tmp1.reg(), index1.reg()));
   __ lea(index2.reg(), FixedArrayElementOperand(tmp1.reg(), index2.reg()));

src/ia32/full-codegen-ia32.cc

@@ -3108,6 +3108,13 @@ void FullCodeGenerator::EmitSwapElements(ZoneList<Expression*>* args) {
   __ test(temp, Immediate(kSmiTagMask));
   __ j(not_zero, &slow_case);
 
+  // Check that both indices are valid.
+  __ mov(temp, FieldOperand(object, JSArray::kLengthOffset));
+  __ cmp(temp, Operand(index_1));
+  __ j(below_equal, &slow_case);
+  __ cmp(temp, Operand(index_2));
+  __ j(below_equal, &slow_case);
+
   // Bring addresses into index1 and index2.
   __ lea(index_1, CodeGenerator::FixedArrayElementOperand(elements, index_1));
   __ lea(index_2, CodeGenerator::FixedArrayElementOperand(elements, index_2));

src/x64/codegen-x64.cc

@@ -6782,6 +6782,13 @@ void CodeGenerator::GenerateSwapElements(ZoneList<Expression*>* args) {
   Condition both_smi = masm()->CheckBothSmi(index1.reg(), index2.reg());
   deferred->Branch(NegateCondition(both_smi));
 
+  // Check that both indices are valid.
+  __ movq(tmp2.reg(), FieldOperand(object.reg(), JSArray::kLengthOffset));
+  __ cmpl(tmp2.reg(), index1.reg());
+  deferred->Branch(below_equal);
+  __ cmpl(tmp2.reg(), index2.reg());
+  deferred->Branch(below_equal);
+
   // Bring addresses into index1 and index2.
   __ SmiToInteger32(index1.reg(), index1.reg());
   __ lea(index1.reg(), FieldOperand(tmp1.reg(),

test/mjsunit/regress/regress-swapelements.js

@@ -0,0 +1,55 @@
+// Copyright 2010 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.
+
+// Check that modifying an array while sorting it does not segfault. See
+// http://code.google.com/p/chromium/issues/detail?id=66099.
+
+function Item(val) {
+    this.value = val;
+}
+
+
+var size = 23;
+var array1 = new Array(size);
+
+
+function myToString() {
+    array1.splice(0, 1);
+    return this.value.toString();
+}
+
+
+function test() {
+    for (var i = 0; i < size; i++) {
+	array1[i] = new Item(i);
+	array1[i].toString = myToString;
+    }
+    array1.sort();
+}
+
+
+test();