| // Copyright (c) 2012, 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" // Needed here to get TARGET_ARCH_IA32. |
| #if defined(TARGET_ARCH_IA32) |
| |
| #include "platform/unaligned.h" |
| #include "vm/code_patcher.h" |
| #include "vm/cpu.h" |
| #include "vm/dart_entry.h" |
| #include "vm/instructions.h" |
| #include "vm/object.h" |
| #include "vm/raw_object.h" |
| |
| namespace dart { |
| |
| // The expected pattern of a Dart unoptimized call (static and instance): |
| // mov ECX, ic-data |
| // mov EDI, target-code-object |
| // call target_address (stub) |
| // <- return address |
| class UnoptimizedCall : public ValueObject { |
| public: |
| UnoptimizedCall(uword return_address, const Code& code) |
| : code_(code), start_(return_address - kPatternSize) { |
| ASSERT(IsValid()); |
| } |
| |
| ObjectPtr ic_data() const { |
| return LoadUnaligned(reinterpret_cast<ObjectPtr*>(start_ + 1)); |
| } |
| |
| static constexpr int kMovInstructionSize = 5; |
| static constexpr int kCallInstructionSize = 3; |
| static constexpr int kPatternSize = |
| 2 * kMovInstructionSize + kCallInstructionSize; |
| |
| private: |
| bool IsValid() { |
| uint8_t* code_bytes = reinterpret_cast<uint8_t*>(start_); |
| return (code_bytes[0] == 0xB9) && |
| (code_bytes[2 * kMovInstructionSize] == 0xFF); |
| } |
| |
| uword return_address() const { return start_ + kPatternSize; } |
| |
| uword call_address() const { return start_ + 2 * kMovInstructionSize; } |
| |
| protected: |
| const Code& code_; |
| uword start_; |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(UnoptimizedCall); |
| }; |
| |
| class NativeCall : public UnoptimizedCall { |
| public: |
| NativeCall(uword return_address, const Code& code) |
| : UnoptimizedCall(return_address, code) {} |
| |
| NativeFunction native_function() const { |
| return LoadUnaligned(reinterpret_cast<NativeFunction*>(start_ + 1)); |
| } |
| |
| void set_native_function(NativeFunction func) const { |
| Thread::Current()->isolate_group()->RunWithStoppedMutators([&]() { |
| WritableInstructionsScope writable(start_ + 1, sizeof(func)); |
| StoreUnaligned(reinterpret_cast<NativeFunction*>(start_ + 1), func); |
| }); |
| } |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(NativeCall); |
| }; |
| |
| // b9xxxxxxxx mov ecx,<data> |
| // bfyyyyyyyy mov edi,<target> |
| // ff5707 call [edi+<monomorphic-entry-offset>] |
| class InstanceCall : public UnoptimizedCall { |
| public: |
| InstanceCall(uword return_address, const Code& code) |
| : UnoptimizedCall(return_address, code) { |
| #if defined(DEBUG) |
| Object& test_data = Object::Handle(data()); |
| ASSERT(test_data.IsArray() || test_data.IsICData() || |
| test_data.IsMegamorphicCache()); |
| if (test_data.IsICData()) { |
| ASSERT(ICData::Cast(test_data).NumArgsTested() > 0); |
| } |
| #endif // DEBUG |
| } |
| |
| ObjectPtr data() const { |
| return LoadUnaligned(reinterpret_cast<ObjectPtr*>(start_ + 1)); |
| } |
| void set_data(const Object& data) const { |
| // N.B. The pointer is embedded in the Instructions object, but visited |
| // through the Code object. |
| code_.StorePointerUnaligned(reinterpret_cast<ObjectPtr*>(start_ + 1), |
| data.ptr(), Thread::Current()); |
| } |
| |
| CodePtr target() const { |
| return LoadUnaligned(reinterpret_cast<CodePtr*>(start_ + 6)); |
| } |
| void set_target(const Code& target) const { |
| // N.B. The pointer is embedded in the Instructions object, but visited |
| // through the Code object. |
| code_.StorePointerUnaligned(reinterpret_cast<CodePtr*>(start_ + 6), |
| target.ptr(), Thread::Current()); |
| } |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(InstanceCall); |
| }; |
| |
| class UnoptimizedStaticCall : public UnoptimizedCall { |
| public: |
| UnoptimizedStaticCall(uword return_address, const Code& code) |
| : UnoptimizedCall(return_address, code) { |
| #if defined(DEBUG) |
| ICData& test_ic_data = ICData::Handle(); |
| test_ic_data ^= ic_data(); |
| ASSERT(test_ic_data.NumArgsTested() >= 0); |
| #endif // DEBUG |
| } |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(UnoptimizedStaticCall); |
| }; |
| |
| // The expected pattern of a dart static call: |
| // mov EDX, arguments_descriptor_array (optional in polymorphic calls) |
| // mov EDI, Immediate(code_object) |
| // call [EDI + entry_point_offset] |
| // <- return address |
| class StaticCall : public ValueObject { |
| public: |
| StaticCall(uword return_address, const Code& code) |
| : code_(code), |
| start_(return_address - (kMovInstructionSize + kCallInstructionSize)) { |
| ASSERT(IsValid()); |
| } |
| |
| bool IsValid() { |
| uint8_t* code_bytes = reinterpret_cast<uint8_t*>(start_); |
| return (code_bytes[0] == 0xBF) && (code_bytes[5] == 0xFF); |
| } |
| |
| CodePtr target() const { |
| return LoadUnaligned(reinterpret_cast<CodePtr*>(start_ + 1)); |
| } |
| |
| void set_target(const Code& target) const { |
| // N.B. The pointer is embedded in the Instructions object, but visited |
| // through the Code object. |
| code_.StorePointerUnaligned(reinterpret_cast<CodePtr*>(start_ + 1), |
| target.ptr(), Thread::Current()); |
| } |
| |
| static constexpr int kMovInstructionSize = 5; |
| static constexpr int kCallInstructionSize = 3; |
| |
| private: |
| uword return_address() const { |
| return start_ + kMovInstructionSize + kCallInstructionSize; |
| } |
| |
| uword call_address() const { return start_ + kMovInstructionSize; } |
| |
| const Code& code_; |
| uword start_; |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(StaticCall); |
| }; |
| |
| CodePtr CodePatcher::GetStaticCallTargetAt(uword return_address, |
| const Code& code) { |
| ASSERT(code.ContainsInstructionAt(return_address)); |
| StaticCall call(return_address, code); |
| return call.target(); |
| } |
| |
| void CodePatcher::PatchStaticCallAt(uword return_address, |
| const Code& code, |
| const Code& new_target) { |
| auto thread = Thread::Current(); |
| auto zone = thread->zone(); |
| const Instructions& instrs = Instructions::Handle(zone, code.instructions()); |
| thread->isolate_group()->RunWithStoppedMutators([&]() { |
| WritableInstructionsScope writable(instrs.PayloadStart(), instrs.Size()); |
| ASSERT(code.ContainsInstructionAt(return_address)); |
| StaticCall call(return_address, code); |
| call.set_target(new_target); |
| }); |
| } |
| |
| void CodePatcher::InsertDeoptimizationCallAt(uword start) { |
| UNREACHABLE(); |
| } |
| |
| CodePtr CodePatcher::GetInstanceCallAt(uword return_address, |
| const Code& caller_code, |
| Object* data) { |
| ASSERT(caller_code.ContainsInstructionAt(return_address)); |
| InstanceCall call(return_address, caller_code); |
| if (data != nullptr) { |
| *data = call.data(); |
| } |
| return call.target(); |
| } |
| |
| void CodePatcher::PatchInstanceCallAt(uword return_address, |
| const Code& caller_code, |
| const Object& data, |
| const Code& target) { |
| auto thread = Thread::Current(); |
| thread->isolate_group()->RunWithStoppedMutators([&]() { |
| PatchInstanceCallAtWithMutatorsStopped(thread, return_address, caller_code, |
| data, target); |
| }); |
| } |
| |
| void CodePatcher::PatchInstanceCallAtWithMutatorsStopped( |
| Thread* thread, |
| uword return_address, |
| const Code& caller_code, |
| const Object& data, |
| const Code& target) { |
| auto zone = thread->zone(); |
| ASSERT(caller_code.ContainsInstructionAt(return_address)); |
| const Instructions& instrs = |
| Instructions::Handle(zone, caller_code.instructions()); |
| WritableInstructionsScope writable(instrs.PayloadStart(), instrs.Size()); |
| InstanceCall call(return_address, caller_code); |
| call.set_data(data); |
| call.set_target(target); |
| } |
| |
| FunctionPtr CodePatcher::GetUnoptimizedStaticCallAt(uword return_address, |
| const Code& caller_code, |
| ICData* ic_data_result) { |
| ASSERT(caller_code.ContainsInstructionAt(return_address)); |
| UnoptimizedStaticCall static_call(return_address, caller_code); |
| ICData& ic_data = ICData::Handle(); |
| ic_data ^= static_call.ic_data(); |
| if (ic_data_result != nullptr) { |
| *ic_data_result = ic_data.ptr(); |
| } |
| return ic_data.GetTargetAt(0); |
| } |
| |
| void CodePatcher::PatchSwitchableCallAt(uword return_address, |
| const Code& caller_code, |
| const Object& data, |
| const Code& target) { |
| // Switchable instance calls only generated for precompilation. |
| UNREACHABLE(); |
| } |
| |
| void CodePatcher::PatchSwitchableCallAtWithMutatorsStopped( |
| Thread* thread, |
| uword return_address, |
| const Code& caller_code, |
| const Object& data, |
| const Code& target) { |
| // Switchable instance calls only generated for precompilation. |
| UNREACHABLE(); |
| } |
| |
| uword CodePatcher::GetSwitchableCallTargetEntryAt(uword return_address, |
| const Code& caller_code) { |
| // Switchable instance calls only generated for precompilation. |
| UNREACHABLE(); |
| return 0; |
| } |
| |
| ObjectPtr CodePatcher::GetSwitchableCallDataAt(uword return_address, |
| const Code& caller_code) { |
| // Switchable instance calls only generated for precompilation. |
| UNREACHABLE(); |
| return Object::null(); |
| } |
| |
| void CodePatcher::PatchNativeCallAt(uword return_address, |
| const Code& caller_code, |
| NativeFunction target, |
| const Code& trampoline) { |
| UNREACHABLE(); |
| } |
| |
| CodePtr CodePatcher::GetNativeCallAt(uword return_address, |
| const Code& caller_code, |
| NativeFunction* target) { |
| UNREACHABLE(); |
| return nullptr; |
| } |
| |
| } // namespace dart |
| |
| #endif // defined TARGET_ARCH_IA32 |