Support verified heap pointer writes on ia32.

runtime/vm/assembler_ia32.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/cpu.h"
 #include "vm/heap.h"
 #include "vm/memory_region.h"
 #include "vm/runtime_entry.h"
 #include "vm/stack_frame.h"
 #include "vm/stub_code.h"
+#include "vm/verified_memory.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, print_stop_message, true, "Print stop message.");
 DECLARE_FLAG(bool, inline_alloc);
 
 
 class DirectCallRelocation : public AssemblerFixup {
  public:
   void Process(const MemoryRegion& region, intptr_t position) {
@@ skipping 2165 matching lines @@
   // Mask out higher, uninteresting bits which were polluted by dest.
   andl(value, Immediate(kObjectAlignment - 1));
   // Compare with the expected bit pattern.
   cmpl(value, Immediate(
       (kNewObjectAlignmentOffset >> 1) + kHeapObjectTag +
       kOldObjectAlignmentOffset + kHeapObjectTag));
   j(NOT_ZERO, no_update, Assembler::kNearJump);
 }
 
 
+void Assembler::VerifiedWrite(const Address& dest, Register value) {
+  // TODO(koda): Verify previous value.
+  movl(dest, value);
+  if (VerifiedMemory::enabled()) {
+    Register temp = (value == EDX) ? ECX : EDX;
+    pushl(temp);
+    leal(temp, dest);
+    movl(Address(temp, VerifiedMemory::offset()), value);
+    popl(temp);
+  }
+}
+
+
 // Destroys the value register.
 void Assembler::StoreIntoObject(Register object,
                                 const Address& dest,
                                 Register value,
                                 bool can_value_be_smi) {
   ASSERT(object != value);
-  movl(dest, value);
+  VerifiedWrite(dest, value);
   Label done;
   if (can_value_be_smi) {
     StoreIntoObjectFilter(object, value, &done);
   } else {
     StoreIntoObjectFilterNoSmi(object, value, &done);
   }
   // A store buffer update is required.
   if (value != EDX) {
     pushl(EDX);  // Preserve EDX.
   }
   if (object != EDX) {
     movl(EDX, object);
   }
   StubCode* stub_code = Isolate::Current()->stub_code();
   call(&stub_code->UpdateStoreBufferLabel());
   if (value != EDX) {
     popl(EDX);  // Restore EDX.
   }
   Bind(&done);
 }
 
 
 void Assembler::StoreIntoObjectNoBarrier(Register object,
                                          const Address& dest,
                                          Register value) {
-  movl(dest, value);
+  VerifiedWrite(dest, value);
 #if defined(DEBUG)
   Label done;
   pushl(value);
   StoreIntoObjectFilter(object, value, &done);
   Stop("Store buffer update is required");
   Bind(&done);
   popl(value);
 #endif  // defined(DEBUG)
   // No store buffer update.
 }
 
 
+void Assembler::UnverifiedStoreOldObject(const Address& dest,
+                                         const Object& value) {
+  ASSERT(value.IsOld());
+  ASSERT(!value.InVMHeap());
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitUint8(0xC7);
+  EmitOperand(0, dest);
+  buffer_.EmitObject(value);
+}
+
+
 void Assembler::StoreIntoObjectNoBarrier(Register object,
                                          const Address& dest,
                                          const Object& value) {
   if (value.IsSmi() || value.InVMHeap()) {
-    movl(dest, Immediate(reinterpret_cast<int32_t>(value.raw())));
+    // TODO(koda): Verify previous value.
+    Immediate imm_value(reinterpret_cast<int32_t>(value.raw()));
+    movl(dest, imm_value);
+    if (VerifiedMemory::enabled()) {
+      Register temp = ECX;
+      pushl(temp);
+      leal(temp, dest);
+      movl(Address(temp, VerifiedMemory::offset()), imm_value);
+      popl(temp);
+    }
   } else {
-    ASSERT(value.IsOld());
-    AssemblerBuffer::EnsureCapacity ensured(&buffer_);
-    EmitUint8(0xC7);
-    EmitOperand(0, dest);
-    buffer_.EmitObject(value);
+    UnverifiedStoreOldObject(dest, value);
+    if (VerifiedMemory::enabled()) {
+      Register temp = EDX;
+      pushl(temp);
+      leal(temp, dest);
+      UnverifiedStoreOldObject(Address(temp, VerifiedMemory::offset()), value);
+      popl(temp);
+    }
   }
   // No store buffer update.
 }
 
 
 void Assembler::StoreIntoSmiField(const Address& dest, Register value) {
-  movl(dest, value);
+  VerifiedWrite(dest, value);
 #if defined(DEBUG)
   Label done;
   testl(value, Immediate(kHeapObjectTag));
   j(ZERO, &done);
   Stop("Smi expected");
   Bind(&done);
 #endif  // defined(DEBUG)
 }
 
 
+void Assembler::ZeroSmiField(const Address& dest) {
+  Immediate zero(Smi::RawValue(0));

[Ivan Posva, 2014/11/12 21:22:49]

Add TODO

[koda, 2014/11/12 23:47:30]

Done.

+  movl(dest, zero);
+  if (VerifiedMemory::enabled()) {
+    Register temp = ECX;
+    pushl(temp);
+    leal(temp, dest);
+    movl(Address(temp, VerifiedMemory::offset()), zero);
+    popl(temp);
+  }
+}
+
+
 void Assembler::IncrementSmiField(const Address& dest, int32_t increment) {
+  // Note: FlowGraphCompiler::EdgeCounterIncrementSizeInBytes depends on
+  // the length of this instruction sequence.
+  //
   // TODO(koda): Implement testl for addresses and check that dest is a smi.
-  addl(dest, Immediate(Smi::RawValue(increment)));
+  Immediate inc_imm(Smi::RawValue(increment));
+  addl(dest, inc_imm);
+  if (VerifiedMemory::enabled()) {
+    Register temp = ECX;
+    pushl(temp);
+    leal(temp, dest);
+    addl(Address(temp, VerifiedMemory::offset()), inc_imm);
+    popl(temp);
+  }
 }
 
 
 void Assembler::LoadDoubleConstant(XmmRegister dst, double value) {
   // TODO(5410843): Need to have a code constants table.
   int64_t constant = bit_cast<int64_t, double>(value);
   pushl(Immediate(Utils::High32Bits(constant)));
   pushl(Immediate(Utils::Low32Bits(constant)));
   movsd(dst, Address(ESP, 0));
   addl(ESP, Immediate(2 * kWordSize));
@@ skipping 609 matching lines @@
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfXmmRegisters));
   return xmm_reg_names[reg];
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32