Out of bounds memory access in TestJSArrayForAllocationSiteInfo.

src/arm/macro-assembler-arm.cc

 // Copyright 2012 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
@@ skipping 3871 matching lines @@
 void MacroAssembler::TestJSArrayForAllocationSiteInfo(
     Register receiver_reg,
     Register scratch_reg,
     Label* allocation_info_present) {
   Label no_info_available;
   ExternalReference new_space_start =
       ExternalReference::new_space_start(isolate());
   ExternalReference new_space_allocation_top =
       ExternalReference::new_space_allocation_top_address(isolate());
   ldr(scratch_reg, FieldMemOperand(receiver_reg,
-                                   JSArray::kSize + AllocationSiteInfo::kSize));
+      JSArray::kSize + AllocationSiteInfo::kSize - kHeapObjectTag));
   cmp(scratch_reg, Operand(new_space_start));
   b(lt, &no_info_available);
   cmp(scratch_reg, Operand(new_space_allocation_top));
-  b(hs, &no_info_available);
-  ldr(scratch_reg, MemOperand(scratch_reg, 0));
+  b(gt, &no_info_available);
+  ldr(scratch_reg, MemOperand(scratch_reg, -AllocationSiteInfo::kSize));
   cmp(scratch_reg,
       Operand(Handle<Map>(isolate()->heap()->allocation_site_info_map())));
   b(eq, allocation_info_present);
   bind(&no_info_available);
 }
 
 
 #ifdef DEBUG
 bool AreAliased(Register reg1,
                 Register reg2,
@@ skipping 53 matching lines @@
 void CodePatcher::EmitCondition(Condition cond) {
   Instr instr = Assembler::instr_at(masm_.pc_);
   instr = (instr & ~kCondMask) | cond;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM