// Copyright 2016 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 "test/fuzzer/wasm-fuzzer-common.h" #include <ctime> #include "include/v8.h" #include "src/isolate.h" #include "src/objects-inl.h" #include "src/ostreams.h" #include "src/wasm/wasm-engine.h" #include "src/wasm/wasm-module-builder.h" #include "src/wasm/wasm-module.h" #include "src/wasm/wasm-objects-inl.h" #include "src/zone/accounting-allocator.h" #include "src/zone/zone.h" #include "test/common/wasm/flag-utils.h" #include "test/common/wasm/wasm-module-runner.h" #include "test/fuzzer/fuzzer-support.h" namespace v8 { namespace internal { namespace wasm { namespace fuzzer { void InterpretAndExecuteModule(i::Isolate* isolate, Handle<WasmModuleObject> module_object) { // We do not instantiate the module if there is a start function, because a // start function can contain an infinite loop which we cannot handle. if (module_object->module()->start_function_index >= 0) return; ErrorThrower thrower(isolate, "WebAssembly Instantiation"); MaybeHandle<WasmInstanceObject> maybe_instance; Handle<WasmInstanceObject> instance; // Try to instantiate and interpret the module_object. maybe_instance = isolate->wasm_engine()->SyncInstantiate( isolate, &thrower, module_object, Handle<JSReceiver>::null(), // imports MaybeHandle<JSArrayBuffer>()); // memory if (!maybe_instance.ToHandle(&instance)) { isolate->clear_pending_exception(); thrower.Reset(); // Ignore errors. return; } if (!testing::InterpretWasmModuleForTesting(isolate, instance, "main", 0, nullptr)) { isolate->clear_pending_exception(); return; } // Try to instantiate and execute the module_object. maybe_instance = isolate->wasm_engine()->SyncInstantiate( isolate, &thrower, module_object, Handle<JSReceiver>::null(), // imports MaybeHandle<JSArrayBuffer>()); // memory if (!maybe_instance.ToHandle(&instance)) { isolate->clear_pending_exception(); thrower.Reset(); // Ignore errors. return; } if (testing::RunWasmModuleForTesting(isolate, instance, 0, nullptr) < 0) { isolate->clear_pending_exception(); return; } } namespace { struct PrintSig { const size_t num; const std::function<ValueType(size_t)> getter; }; PrintSig PrintParameters(const FunctionSig* sig) { return {sig->parameter_count(), [=](size_t i) { return sig->GetParam(i); }}; } PrintSig PrintReturns(const FunctionSig* sig) { return {sig->return_count(), [=](size_t i) { return sig->GetReturn(i); }}; } const char* ValueTypeToConstantName(ValueType type) { switch (type) { case kWasmI32: return "kWasmI32"; case kWasmI64: return "kWasmI64"; case kWasmF32: return "kWasmF32"; case kWasmF64: return "kWasmF64"; default: UNREACHABLE(); } } std::ostream& operator<<(std::ostream& os, const PrintSig& print) { os << "["; for (size_t i = 0; i < print.num; ++i) { os << (i == 0 ? "" : ", ") << ValueTypeToConstantName(print.getter(i)); } return os << "]"; } struct PrintName { WasmName name; PrintName(ModuleWireBytes wire_bytes, WireBytesRef ref) : name(wire_bytes.GetNameOrNull(ref)) {} }; std::ostream& operator<<(std::ostream& os, const PrintName& name) { return os.write(name.name.start(), name.name.size()); } } // namespace void GenerateTestCase(Isolate* isolate, ModuleWireBytes wire_bytes, bool compiles) { constexpr bool kVerifyFunctions = false; auto enabled_features = i::wasm::WasmFeaturesFromIsolate(isolate); ModuleResult module_res = DecodeWasmModule( enabled_features, wire_bytes.start(), wire_bytes.end(), kVerifyFunctions, ModuleOrigin::kWasmOrigin, isolate->counters(), isolate->allocator()); CHECK(module_res.ok()); WasmModule* module = module_res.value().get(); CHECK_NOT_NULL(module); StdoutStream os; tzset(); time_t current_time = time(nullptr); struct tm current_localtime; #ifdef V8_OS_WIN localtime_s(¤t_localtime, ¤t_time); #else localtime_r(¤t_time, ¤t_localtime); #endif int year = 1900 + current_localtime.tm_year; os << "// Copyright " << year << " the V8 project authors. All rights reserved.\n" "// Use of this source code is governed by a BSD-style license that " "can be\n" "// found in the LICENSE file.\n" "\n" "load('test/mjsunit/wasm/wasm-module-builder.js');\n" "\n" "(function() {\n" " const builder = new WasmModuleBuilder();\n"; if (module->has_memory) { os << " builder.addMemory(" << module->initial_pages; if (module->has_maximum_pages) { os << ", " << module->maximum_pages; } else { os << ", undefined"; } os << ", " << (module->mem_export ? "true" : "false"); if (module->has_shared_memory) { os << ", true"; } os << ");\n"; } for (WasmGlobal& glob : module->globals) { os << " builder.addGlobal(" << ValueTypeToConstantName(glob.type) << ", " << glob.mutability << ");\n"; } for (const FunctionSig* sig : module->signatures) { os << " builder.addType(makeSig(" << PrintParameters(sig) << ", " << PrintReturns(sig) << "));\n"; } Zone tmp_zone(isolate->allocator(), ZONE_NAME); // There currently cannot be more than one table. DCHECK_GE(1, module->tables.size()); for (const WasmTable& table : module->tables) { os << " builder.setTableBounds(" << table.initial_size << ", "; if (table.has_maximum_size) { os << table.maximum_size << ");\n"; } else { os << "undefined);\n"; } } for (const WasmElemSegment& elem_segment : module->elem_segments) { os << " builder.addElementSegment("; switch (elem_segment.offset.kind) { case WasmInitExpr::kGlobalIndex: os << elem_segment.offset.val.global_index << ", true"; break; case WasmInitExpr::kI32Const: os << elem_segment.offset.val.i32_const << ", false"; break; default: UNREACHABLE(); } os << ", " << PrintCollection(elem_segment.entries) << ");\n"; } for (const WasmFunction& func : module->functions) { Vector<const uint8_t> func_code = wire_bytes.GetFunctionBytes(&func); os << " // Generate function " << (func.func_index + 1) << " (out of " << module->functions.size() << ").\n"; // Add function. os << " builder.addFunction(undefined, " << func.sig_index << " /* sig */)\n"; // Add locals. BodyLocalDecls decls(&tmp_zone); DecodeLocalDecls(enabled_features, &decls, func_code.start(), func_code.end()); if (!decls.type_list.empty()) { os << " "; for (size_t pos = 0, count = 1, locals = decls.type_list.size(); pos < locals; pos += count, count = 1) { ValueType type = decls.type_list[pos]; while (pos + count < locals && decls.type_list[pos + count] == type) ++count; os << ".addLocals({" << ValueTypes::TypeName(type) << "_count: " << count << "})"; } os << "\n"; } // Add body. os << " .addBodyWithEnd([\n"; FunctionBody func_body(func.sig, func.code.offset(), func_code.start(), func_code.end()); PrintRawWasmCode(isolate->allocator(), func_body, module, kOmitLocals); os << " ]);\n"; } for (WasmExport& exp : module->export_table) { if (exp.kind != kExternalFunction) continue; os << " builder.addExport('" << PrintName(wire_bytes, exp.name) << "', " << exp.index << ");\n"; } if (compiles) { os << " const instance = builder.instantiate();\n" " print(instance.exports.main(1, 2, 3));\n"; } else { os << " assertThrows(function() { builder.instantiate(); }, " "WebAssembly.CompileError);\n"; } os << "})();\n"; } void WasmExecutionFuzzer::FuzzWasmModule(Vector<const uint8_t> data, bool require_valid) { // Strictly enforce the input size limit. Note that setting "max_len" on the // fuzzer target is not enough, since different fuzzers are used and not all // respect that limit. if (data.size() > max_input_size()) return; v8_fuzzer::FuzzerSupport* support = v8_fuzzer::FuzzerSupport::Get(); v8::Isolate* isolate = support->GetIsolate(); i::Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate); // Clear any pending exceptions from a prior run. 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); HandleScope scope(i_isolate); AccountingAllocator allocator; Zone zone(&allocator, ZONE_NAME); ZoneBuffer buffer(&zone); int32_t num_args = 0; std::unique_ptr<WasmValue[]> interpreter_args; std::unique_ptr<Handle<Object>[]> compiler_args; // The first byte builds the bitmask to control which function will be // compiled with Turbofan and which one with Liftoff. uint8_t tier_mask = data.is_empty() ? 0 : data[0]; if (!data.is_empty()) data += 1; if (!GenerateModule(i_isolate, &zone, data, buffer, num_args, interpreter_args, compiler_args)) { return; } testing::SetupIsolateForWasmModule(i_isolate); ErrorThrower interpreter_thrower(i_isolate, "Interpreter"); ModuleWireBytes wire_bytes(buffer.begin(), buffer.end()); // Compile with Turbofan here. Liftoff will be tested later. auto enabled_features = i::wasm::WasmFeaturesFromIsolate(i_isolate); MaybeHandle<WasmModuleObject> compiled_module; { // Explicitly enable Liftoff, disable tiering and set the tier_mask. This // way, we deterministically test a combination of Liftoff and Turbofan. FlagScope<bool> liftoff(&FLAG_liftoff, true); FlagScope<bool> no_tier_up(&FLAG_wasm_tier_up, false); FlagScope<int> tier_mask_scope(&FLAG_wasm_tier_mask_for_testing, tier_mask); compiled_module = i_isolate->wasm_engine()->SyncCompile( i_isolate, enabled_features, &interpreter_thrower, wire_bytes); } bool compiles = !compiled_module.is_null(); if (FLAG_wasm_fuzzer_gen_test) { GenerateTestCase(i_isolate, wire_bytes, compiles); } bool validates = i_isolate->wasm_engine()->SyncValidate( i_isolate, enabled_features, wire_bytes); CHECK_EQ(compiles, validates); CHECK_IMPLIES(require_valid, validates); if (!compiles) return; MaybeHandle<WasmInstanceObject> interpreter_instance = i_isolate->wasm_engine()->SyncInstantiate( i_isolate, &interpreter_thrower, compiled_module.ToHandleChecked(), MaybeHandle<JSReceiver>(), MaybeHandle<JSArrayBuffer>()); // Ignore instantiation failure. if (interpreter_thrower.error()) return; testing::WasmInterpretationResult interpreter_result = testing::InterpretWasmModule(i_isolate, interpreter_instance.ToHandleChecked(), 0, interpreter_args.get()); // Do not execute the generated code if the interpreter did not finished after // a bounded number of steps. if (interpreter_result.stopped()) return; // The WebAssembly spec allows the sign bit of NaN to be non-deterministic. // This sign bit can make the difference between an infinite loop and // terminating code. With possible non-determinism we cannot guarantee that // the generated code will not go into an infinite loop and cause a timeout in // Clusterfuzz. Therefore we do not execute the generated code if the result // may be non-deterministic. if (interpreter_result.possible_nondeterminism()) return; int32_t result_compiled; { ErrorThrower compiler_thrower(i_isolate, "Compile"); MaybeHandle<WasmInstanceObject> compiled_instance = i_isolate->wasm_engine()->SyncInstantiate( i_isolate, &compiler_thrower, compiled_module.ToHandleChecked(), MaybeHandle<JSReceiver>(), MaybeHandle<JSArrayBuffer>()); DCHECK(!compiler_thrower.error()); result_compiled = testing::CallWasmFunctionForTesting( i_isolate, compiled_instance.ToHandleChecked(), &compiler_thrower, "main", num_args, compiler_args.get()); } if (interpreter_result.trapped() != i_isolate->has_pending_exception()) { const char* exception_text[] = {"no exception", "exception"}; FATAL("interpreter: %s; compiled: %s", exception_text[interpreter_result.trapped()], exception_text[i_isolate->has_pending_exception()]); } if (!interpreter_result.trapped()) { CHECK_EQ(interpreter_result.result(), result_compiled); } // Cleanup any pending exception. i_isolate->clear_pending_exception(); } } // namespace fuzzer } // namespace wasm } // namespace internal } // namespace v8