commit 4d02711ea578dbb789abb30cbaf12f9926e13d81
author Roland Levillain <rpl@google.com> Wed Jul 01 15:41:14 2015 +0100
committer Roland Levillain <rpl@google.com> Wed Jul 01 16:31:41 2015 +0100
tree 29c802afff6e73c06021c44e6b2ec9d8340c75e9
parent 312f1bfcfd8f655e635c941dda147377d8bff814

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

compiler/utils/x86/assembler_x86.cc

diff --git a/compiler/utils/x86/assembler_x86.cc b/compiler/utils/x86/assembler_x86.cc
index 390d46e..fa85ada 100644
--- a/compiler/utils/x86/assembler_x86.cc
+++ b/compiler/utils/x86/assembler_x86.cc
@@ -1910,12 +1910,12 @@
 }
 
 void X86Assembler::LoadRef(ManagedRegister mdest, ManagedRegister base, MemberOffset offs,
-                           bool poison_reference) {
+                           bool unpoison_reference) {
   X86ManagedRegister dest = mdest.AsX86();
   CHECK(dest.IsCpuRegister() && dest.IsCpuRegister());
   movl(dest.AsCpuRegister(), Address(base.AsX86().AsCpuRegister(), offs));
-  if (kPoisonHeapReferences && poison_reference) {
-    negl(dest.AsCpuRegister());
+  if (unpoison_reference) {
+    MaybeUnpoisonHeapReference(dest.AsCpuRegister());
   }
 }
 

compiler/utils/x86/assembler_x86.h

diff --git a/compiler/utils/x86/assembler_x86.h b/compiler/utils/x86/assembler_x86.h
index 1c1c023..d1b4e1d 100644
--- a/compiler/utils/x86/assembler_x86.h
+++ b/compiler/utils/x86/assembler_x86.h
@@ -541,7 +541,7 @@
   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;
 
@@ -616,6 +616,21 @@
   // and branch to a ExceptionSlowPath if it is.
   void ExceptionPoll(ManagedRegister scratch, size_t stack_adjust) OVERRIDE;
 
+  //
+  // Heap poisoning.
+  //
+
+  // Poison a heap reference contained in `reg`.
+  void PoisonHeapReference(Register reg) { negl(reg); }
+  // Unpoison a heap reference contained in `reg`.
+  void UnpoisonHeapReference(Register reg) { negl(reg); }
+  // Unpoison a heap reference contained in `reg` if heap poisoning is enabled.
+  void MaybeUnpoisonHeapReference(Register reg) {
+    if (kPoisonHeapReferences) {
+      UnpoisonHeapReference(reg);
+    }
+  }
+
  private:
   inline void EmitUint8(uint8_t value);
   inline void EmitInt32(int32_t value);