Implement heap poisoning in ART's Optimizing compiler.

- Instrument ARM, ARM64, x86 and x86-64 code generators.
- Note: To turn heap poisoning on in Optimizing, set the
  environment variable `ART_HEAP_POISONING' to "true"
  before compiling ART.

Bug: 12687968
Change-Id: Ib3120b38cf805a8a50207a314b9ccc90c8d93740

1 files changed, 22 insertions, 1 deletions

diff --git a/compiler/utils/arm/assembler_arm.h b/compiler/utils/arm/assembler_arm.h
index f8ca48ef57..5d85d11054 100644
--- a/compiler/utils/arm/assembler_arm.h
+++ b/compiler/utils/arm/assembler_arm.h
@@ -774,7 +774,7 @@ class ArmAssembler : public Assembler {
   void LoadRef(ManagedRegister dest, FrameOffset src) OVERRIDE;
 
   void LoadRef(ManagedRegister dest, ManagedRegister base, MemberOffset offs,
-               bool poison_reference) OVERRIDE;
+               bool unpoison_reference) OVERRIDE;
 
   void LoadRawPtr(ManagedRegister dest, ManagedRegister base, Offset offs) OVERRIDE;
 
@@ -857,6 +857,27 @@ class ArmAssembler : public Assembler {
      return r >= R8;
   }
 
+  //
+  // Heap poisoning.
+  //
+
+  // Poison a heap reference contained in `reg`.
+  void PoisonHeapReference(Register reg) {
+    // reg = -reg.
+    rsb(reg, reg, ShifterOperand(0));
+  }
+  // Unpoison a heap reference contained in `reg`.
+  void UnpoisonHeapReference(Register reg) {
+    // reg = -reg.
+    rsb(reg, reg, ShifterOperand(0));
+  }
+  // Unpoison a heap reference contained in `reg` if heap poisoning is enabled.
+  void MaybeUnpoisonHeapReference(Register reg) {
+    if (kPoisonHeapReferences) {
+      UnpoisonHeapReference(reg);
+    }
+  }
+
  protected:
   // Returns whether or not the given register is used for passing parameters.
   static int RegisterCompare(const Register* reg1, const Register* reg2) {