[wasm] Syntax- and Type-aware Fuzzer

test/fuzzer/wasm-compile.cc

+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include <algorithm>
+
+#include "include/v8.h"
+#include "src/isolate.h"
+#include "src/objects-inl.h"
+#include "src/objects.h"
+#include "src/ostreams.h"
+#include "src/wasm/wasm-interpreter.h"
+#include "src/wasm/wasm-module-builder.h"
+#include "src/wasm/wasm-module.h"
+#include "test/common/wasm/test-signatures.h"
+#include "test/common/wasm/wasm-module-runner.h"
+#include "test/fuzzer/fuzzer-support.h"
+
+#define WASM_CODE_FUZZER_HASH_SEED 83
+
+typedef uint8_t byte;
+
+using namespace v8::internal::wasm;
+
+namespace {
+
+class DataRange {
+  const uint8_t* data_;
+  size_t size_;
+
+ public:
+  DataRange(const uint8_t* data, size_t size) : data_(data), size_(size) {}
+
+  size_t size() const { return size_; }
+
+  std::pair<DataRange, DataRange> split(uint32_t index) const {
+    return std::make_pair(DataRange(data_, index),
+                          DataRange(data_ + index, size() - index));
+  }
+
+  std::pair<DataRange, DataRange> split() {
+    uint16_t index = get<uint16_t>();
+    if (size() > 0) {
+      index = index % size();
+    } else {
+      index = 0;
+    }
+    return split(index);
+  }
+
+  template <typename T>
+  T get() {
+    if (size() == 0) {
+      return T();
+    } else {
+      const size_t num_bytes = std::min(sizeof(T), size());
+      T result;
+      memcpy(&result, data_, sizeof(num_bytes));
+      data_ += num_bytes;
+      size_ -= num_bytes;
+      return result;
+    }
+  }
+};
+
+class WasmGenerator {
+  template <WasmOpcode Op, ValueType... Args>
+  std::function<void(DataRange)> op() {
+    return [this](DataRange data) {
+      Generate<Args...>(data);
+      builder_->Emit(Op);
+    };
+  }
+
+  template <ValueType T>
+  std::function<void(DataRange)> block() {
+    return [this](DataRange data) {
+      blocks_.push_back(T);
+      builder_->EmitWithU8(
+          kExprBlock, static_cast<uint8_t>(WasmOpcodes::ValueTypeCodeFor(T)));
+      Generate<T>(data);
+      builder_->Emit(kExprEnd);
+      blocks_.pop_back();
+    };
+  }
+
+  template <ValueType T>
+  std::function<void(DataRange)> block_br() {
+    return [this](DataRange data) {
+      blocks_.push_back(T);
+      builder_->EmitWithU8(
+          kExprBlock, static_cast<uint8_t>(WasmOpcodes::ValueTypeCodeFor(T)));
+
+      const uint32_t target_block = data.get<uint32_t>() % blocks_.size();
+      const ValueType break_type = blocks_[target_block];
+
+      Generate(break_type, data);
+      builder_->EmitWithVarInt(kExprBr, target_block);
+      builder_->Emit(kExprEnd);
+      blocks_.pop_back();
+    };
+  }
+
+ public:
+  WasmGenerator(v8::internal::wasm::WasmFunctionBuilder* fn) : builder_(fn) {}
+
+  void Generate(ValueType type, DataRange data);
+
+  template <ValueType T>
+  void Generate(DataRange data);
+
+  template <ValueType T1, ValueType T2, ValueType... Ts>
+  void Generate(DataRange data) {
+    const auto parts = data.split();
+    Generate<T1>(parts.first);
+    Generate<T2, Ts...>(parts.second);
+  }
+
+ private:
+  v8::internal::wasm::WasmFunctionBuilder* builder_;
+  std::vector<ValueType> blocks_;
+};
+
+template <>
+void WasmGenerator::Generate<kWasmI32>(DataRange data) {
+  if (data.size() <= sizeof(uint32_t)) {
+    builder_->EmitI32Const(data.get<uint32_t>());
+  } else {
+    const std::function<void(DataRange)> alternates[] = {
+        op<kExprI32Eqz, kWasmI32>(),  //
+        op<kExprI32Eq, kWasmI32, kWasmI32>(),
+        op<kExprI32Ne, kWasmI32, kWasmI32>(),
+        op<kExprI32LtS, kWasmI32, kWasmI32>(),
+        op<kExprI32LtU, kWasmI32, kWasmI32>(),
+        op<kExprI32GeS, kWasmI32, kWasmI32>(),
+        op<kExprI32GeU, kWasmI32, kWasmI32>(),
+
+        op<kExprI64Eqz, kWasmI64>(),  //
+        op<kExprI64Eq, kWasmI64, kWasmI64>(),
+        op<kExprI64Ne, kWasmI64, kWasmI64>(),
+        op<kExprI64LtS, kWasmI64, kWasmI64>(),
+        op<kExprI64LtU, kWasmI64, kWasmI64>(),
+        op<kExprI64GeS, kWasmI64, kWasmI64>(),
+        op<kExprI64GeU, kWasmI64, kWasmI64>(),
+
+        op<kExprF32Eq, kWasmF32, kWasmF32>(),
+        op<kExprF32Ne, kWasmF32, kWasmF32>(),
+        op<kExprF32Lt, kWasmF32, kWasmF32>(),
+        op<kExprF32Ge, kWasmF32, kWasmF32>(),
+
+        op<kExprF64Eq, kWasmF64, kWasmF64>(),
+        op<kExprF64Ne, kWasmF64, kWasmF64>(),
+        op<kExprF64Lt, kWasmF64, kWasmF64>(),
+        op<kExprF64Ge, kWasmF64, kWasmF64>(),
+
+        op<kExprI32Add, kWasmI32, kWasmI32>(),
+        op<kExprI32Sub, kWasmI32, kWasmI32>(),
+        op<kExprI32Mul, kWasmI32, kWasmI32>(),
+
+        op<kExprI32DivS, kWasmI32, kWasmI32>(),
+        op<kExprI32DivU, kWasmI32, kWasmI32>(),
+        op<kExprI32RemS, kWasmI32, kWasmI32>(),
+        op<kExprI32RemU, kWasmI32, kWasmI32>(),
+
+        op<kExprI32And, kWasmI32, kWasmI32>(),
+        op<kExprI32Ior, kWasmI32, kWasmI32>(),
+        op<kExprI32Xor, kWasmI32, kWasmI32>(),
+        op<kExprI32Shl, kWasmI32, kWasmI32>(),
+        op<kExprI32ShrU, kWasmI32, kWasmI32>(),
+        op<kExprI32ShrS, kWasmI32, kWasmI32>(),
+        op<kExprI32Ror, kWasmI32, kWasmI32>(),
+        op<kExprI32Rol, kWasmI32, kWasmI32>(),
+
+        op<kExprI32Clz, kWasmI32>(),  //
+        op<kExprI32Ctz, kWasmI32>(),  //
+        op<kExprI32Popcnt, kWasmI32>(),
+
+        op<kExprI32ConvertI64, kWasmI64>(),  //
+        op<kExprI32SConvertF32, kWasmF32>(),
+        op<kExprI32UConvertF32, kWasmF32>(),
+        op<kExprI32SConvertF64, kWasmF64>(),
+        op<kExprI32UConvertF64, kWasmF64>(),
+        // TODO(ahaas): Uncomment this once the nondeterminism detection is
+        // working again.
+        //
+        // op<kExprI32ReinterpretF32, kWasmF32>(),

[ahaas, 2017/02/17 09:03:52]

Nit: I fixed this issue already.

[Eric Holk, 2017/02/17 16:42:09]

Done.

+
+        block<kWasmI32>(), block_br<kWasmI32>()};
+
+    static_assert(arraysize(alternates) < std::numeric_limits<uint8_t>::max(),
+                  "Too many alternates. Replace with a bigger type if needed.");
+    const auto which = data.get<uint8_t>();
+
+    alternates[which % arraysize(alternates)](data);
+  }
+}
+
+template <>
+void WasmGenerator::Generate<kWasmI64>(DataRange data) {
+  if (data.size() <= sizeof(uint64_t)) {
+    const uint8_t bytes[] = {WASM_I64V(data.get<uint64_t>())};
+    builder_->EmitCode(bytes, arraysize(bytes));
+  } else {
+    const std::function<void(DataRange)> alternates[] = {
+        op<kExprI64Add, kWasmI64, kWasmI64>(),
+        op<kExprI64Sub, kWasmI64, kWasmI64>(),
+        op<kExprI64Mul, kWasmI64, kWasmI64>(),
+
+        op<kExprI64DivS, kWasmI64, kWasmI64>(),
+        op<kExprI64DivU, kWasmI64, kWasmI64>(),
+        op<kExprI64RemS, kWasmI64, kWasmI64>(),
+        op<kExprI64RemU, kWasmI64, kWasmI64>(),
+
+        op<kExprI64And, kWasmI64, kWasmI64>(),
+        op<kExprI64Ior, kWasmI64, kWasmI64>(),
+        op<kExprI64Xor, kWasmI64, kWasmI64>(),
+        op<kExprI64Shl, kWasmI64, kWasmI64>(),
+        op<kExprI64ShrU, kWasmI64, kWasmI64>(),
+        op<kExprI64ShrS, kWasmI64, kWasmI64>(),
+        op<kExprI64Ror, kWasmI64, kWasmI64>(),
+        op<kExprI64Rol, kWasmI64, kWasmI64>(),
+
+        op<kExprI64Clz, kWasmI64>(),
+        op<kExprI64Ctz, kWasmI64>(),
+        op<kExprI64Popcnt, kWasmI64>(),
+
+        block<kWasmI64>(),
+        block_br<kWasmI64>()};
+
+    static_assert(arraysize(alternates) < std::numeric_limits<uint8_t>::max(),
+                  "Too many alternates. Replace with a bigger type if needed.");
+    const auto which = data.get<uint8_t>();
+
+    alternates[which % arraysize(alternates)](data);
+  }
+}
+
+template <>
+void WasmGenerator::Generate<kWasmF32>(DataRange data) {
+  if (data.size() <= sizeof(uint32_t)) {
+    const uint32_t i = data.get<uint32_t>();
+    builder_->Emit(kExprF32Const);
+    builder_->EmitCode(reinterpret_cast<const uint8_t*>(&i), sizeof(i));
+  } else {
+    const std::function<void(DataRange)> alternates[] = {
+        op<kExprF32Add, kWasmF32, kWasmF32>(),
+        op<kExprF32Sub, kWasmF32, kWasmF32>(),
+        op<kExprF32Mul, kWasmF32, kWasmF32>(),
+
+        block<kWasmF32>(), block_br<kWasmF32>()};
+
+    static_assert(arraysize(alternates) < std::numeric_limits<uint8_t>::max(),
+                  "Too many alternates. Replace with a bigger type if needed.");
+    const auto which = data.get<uint8_t>();
+
+    alternates[which % arraysize(alternates)](data);
+  }
+}
+
+template <>
+void WasmGenerator::Generate<kWasmF64>(DataRange data) {
+  if (data.size() <= sizeof(uint64_t)) {
+    // TODO (eholk): generate full 64-bit constants
+    uint64_t i = 0;
+    while (data.size() > 0) {
+      i <<= 8;
+      i |= data.get<uint8_t>();
+    }
+    builder_->Emit(kExprF64Const);
+    builder_->EmitCode(reinterpret_cast<uint8_t*>(&i), sizeof(i));
+  } else {
+    const std::function<void(DataRange)> alternates[] = {
+        op<kExprF64Add, kWasmF64, kWasmF64>(),
+        op<kExprF64Sub, kWasmF64, kWasmF64>(),
+        op<kExprF64Mul, kWasmF64, kWasmF64>(),
+
+        block<kWasmF64>(), block_br<kWasmF64>()};
+
+    static_assert(arraysize(alternates) < std::numeric_limits<uint8_t>::max(),
+                  "Too many alternates. Replace with a bigger type if needed.");
+    const auto which = data.get<uint8_t>();
+
+    alternates[which % arraysize(alternates)](data);
+  }
+}
+
+void WasmGenerator::Generate(ValueType type, DataRange data) {
+  switch (type) {
+    case kWasmI32:
+      return Generate<kWasmI32>(data);
+    case kWasmI64:
+      return Generate<kWasmI64>(data);
+    case kWasmF32:
+      return Generate<kWasmF32>(data);
+    case kWasmF64:
+      return Generate<kWasmF64>(data);
+    default:
+      UNREACHABLE();
+  }
+}
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  // Save the flag so that we can change it and restore it later.
+  bool generate_test = v8::internal::FLAG_wasm_code_fuzzer_gen_test;
+  if (generate_test) {
+    v8::internal::OFStream os(stdout);
+
+    os << "// Copyright 2017 the V8 project authors. All rights reserved."
+       << std::endl;
+    os << "// Use of this source code is governed by a BSD-style license that "
+          "can be"
+       << std::endl;
+    os << "// found in the LICENSE file." << std::endl;
+    os << std::endl;
+    os << "load(\"test/mjsunit/wasm/wasm-constants.js\");" << std::endl;
+    os << "load(\"test/mjsunit/wasm/wasm-module-builder.js\");" << std::endl;
+    os << std::endl;
+    os << "(function() {" << std::endl;
+    os << "  var builder = new WasmModuleBuilder();" << std::endl;
+    os << "  builder.addMemory(16, 32, false);" << std::endl;
+    os << "  builder.addFunction(\"test\", kSig_i_iii)" << std::endl;
+    os << "    .addBodyWithEnd([" << std::endl;
+  }
+  v8_fuzzer::FuzzerSupport* support = v8_fuzzer::FuzzerSupport::Get();
+  v8::Isolate* isolate = support->GetIsolate();
+  v8::internal::Isolate* i_isolate =
+      reinterpret_cast<v8::internal::Isolate*>(isolate);
+
+  // Clear any pending exceptions from a prior run.
+  if (i_isolate->has_pending_exception()) {
+    i_isolate->clear_pending_exception();
+  }
+
+  v8::Isolate::Scope isolate_scope(isolate);
+  v8::HandleScope handle_scope(isolate);
+  v8::Context::Scope context_scope(support->GetContext());
+  v8::TryCatch try_catch(isolate);
+
+  v8::internal::AccountingAllocator allocator;
+  v8::internal::Zone zone(&allocator, ZONE_NAME);
+
+  TestSignatures sigs;
+
+  WasmModuleBuilder builder(&zone);
+
+  v8::internal::wasm::WasmFunctionBuilder* f =
+      builder.AddFunction(sigs.i_iii());
+
+  WasmGenerator gen(f);
+  gen.Generate<kWasmI32>(DataRange(data, static_cast<uint32_t>(size)));
+
+  uint8_t end_opcode = kExprEnd;
+  f->EmitCode(&end_opcode, 1);
+  f->ExportAs(v8::internal::CStrVector("main"));
+
+  ZoneBuffer buffer(&zone);
+  builder.WriteTo(buffer);
+
+  v8::internal::wasm::testing::SetupIsolateForWasmModule(i_isolate);
+
+  v8::internal::HandleScope scope(i_isolate);
+
+  ErrorThrower interpreter_thrower(i_isolate, "Interpreter");
+  std::unique_ptr<const WasmModule> module(testing::DecodeWasmModuleForTesting(
+      i_isolate, &interpreter_thrower, buffer.begin(), buffer.end(),
+      v8::internal::wasm::ModuleOrigin::kWasmOrigin, true));
+
+  // Clear the flag so that the WebAssembly code is not printed twice.
+  v8::internal::FLAG_wasm_code_fuzzer_gen_test = false;
+  if (module == nullptr) {
+    if (generate_test) {
+      v8::internal::OFStream os(stdout);
+      os << "            ])" << std::endl;
+      os << "            .exportFunc();" << std::endl;
+      os << "  assertThrows(function() { builder.instantiate(); });"
+         << std::endl;
+      os << "})();" << std::endl;
+    }
+    return 0;
+  }
+  if (generate_test) {
+    v8::internal::OFStream os(stdout);
+    os << "            ])" << std::endl;
+    os << "            .exportFunc();" << std::endl;
+    os << "  var module = builder.instantiate();" << std::endl;
+    os << "  module.exports.test(1, 2, 3);" << std::endl;
+    os << "})();" << std::endl;
+  }
+
+  ModuleWireBytes wire_bytes(buffer.begin(), buffer.end());
+  int32_t result_interpreted;
+  bool possible_nondeterminism = false;
+  {
+    WasmVal args[] = {WasmVal(1), WasmVal(2), WasmVal(3)};
+    result_interpreted = testing::InterpretWasmModule(
+        i_isolate, &interpreter_thrower, module.get(), wire_bytes, 0, args,
+        &possible_nondeterminism);
+  }
+
+  ErrorThrower compiler_thrower(i_isolate, "Compiler");
+  v8::internal::Handle<v8::internal::JSObject> instance =
+      testing::InstantiateModuleForTesting(i_isolate, &compiler_thrower,
+                                           module.get(), wire_bytes);
+  // Restore the flag.
+  v8::internal::FLAG_wasm_code_fuzzer_gen_test = generate_test;
+  if (!interpreter_thrower.error()) {
+    CHECK(!instance.is_null());
+  } else {
+    return 0;
+  }
+  int32_t result_compiled;
+  {
+    v8::internal::Handle<v8::internal::Object> arguments[] = {
+        v8::internal::handle(v8::internal::Smi::FromInt(1), i_isolate),
+        v8::internal::handle(v8::internal::Smi::FromInt(2), i_isolate),
+        v8::internal::handle(v8::internal::Smi::FromInt(3), i_isolate)};
+    result_compiled = testing::CallWasmFunctionForTesting(
+        i_isolate, instance, &compiler_thrower, "main", arraysize(arguments),
+        arguments, v8::internal::wasm::ModuleOrigin::kWasmOrigin);
+  }
+  if (result_interpreted == bit_cast<int32_t>(0xdeadbeef) &&
+      !possible_nondeterminism) {
+    CHECK(i_isolate->has_pending_exception());
+    i_isolate->clear_pending_exception();
+  } else {
+    // The WebAssembly spec allows the sign bit of NaN to be non-deterministic.
+    // This sign bit may cause result_interpreted to be different than
+    // result_compiled. Therefore we do not check the equality of the results
+    // if the execution may have produced a NaN at some point.
+    if (!possible_nondeterminism && (result_interpreted != result_compiled)) {
+      printf("Interpreter returned 0x%x but compiled code returned 0x%x\n",
+             result_interpreted, result_compiled);
+      V8_Fatal(__FILE__, __LINE__, "WasmCodeFuzzerHash=%x",
+               v8::internal::StringHasher::HashSequentialString(
+                   data, static_cast<int>(size), WASM_CODE_FUZZER_HASH_SEED));
+    }
+  }
+  return 0;
+}