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// 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/execution/isolate.h"
#include "src/objects/objects-inl.h"
#include "src/utils/ostreams.h"
#include "src/wasm/wasm-engine.h"
#include "src/wasm/wasm-feature-flags.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.kind()) {
case ValueType::kI32:
return "kWasmI32";
case ValueType::kI64:
return "kWasmI64";
case ValueType::kF32:
return "kWasmF32";
case ValueType::kF64:
return "kWasmF64";
case ValueType::kAnyRef:
return "kWasmAnyRef";
case ValueType::kFuncRef:
return "kWasmFuncRef";
case ValueType::kExnRef:
return "kWasmExnRef";
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.begin(), name.name.size());
}
} // namespace
void GenerateTestCase(Isolate* isolate, ModuleWireBytes wire_bytes,
bool compiles) {
constexpr bool kVerifyFunctions = false;
auto enabled_features = i::wasm::WasmFeatures::FromIsolate(isolate);
ModuleResult module_res = DecodeWasmModule(
enabled_features, wire_bytes.start(), wire_bytes.end(), kVerifyFunctions,
ModuleOrigin::kWasmOrigin, isolate->counters(),
isolate->wasm_engine()->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"
"// Flags: --wasm-staging\n"
"\n"
"load('test/mjsunit/wasm/wasm-module-builder.js');\n"
"\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";
}
// TODO(7748): Support array/struct types.
#if DEBUG
for (uint8_t kind : module->type_kinds) {
DCHECK_EQ(kWasmFunctionTypeCode, kind);
}
#endif
for (TypeDefinition type : module->types) {
const FunctionSig* sig = type.function_sig;
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(";
os << elem_segment.table_index << ", ";
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.begin(),
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({" << type.type_name() << "_count: " << count << "})";
}
os << "\n";
}
// Add body.
os << " .addBodyWithEnd([\n";
FunctionBody func_body(func.sig, func.code.offset(), func_code.begin(),
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";
}
}
void WasmExecutionFuzzer::FuzzWasmModule(Vector<const uint8_t> data,
bool require_valid) {
// We explicitly enable staged WebAssembly features here to increase fuzzer
// coverage. For libfuzzer fuzzers it is not possible that the fuzzer enables
// the flag by itself.
#define ENABLE_STAGED_FEATURES(feat, desc, val) \
FlagScope<bool> enable_##feat(&FLAG_experimental_wasm_##feat, true);
FOREACH_WASM_STAGING_FEATURE_FLAG(ENABLE_STAGED_FEATURES)
#undef ENABLE_STAGED_FEATURES
// SIMD is not included in staging yet, so we enable it here for fuzzing.
EXPERIMENTAL_FLAG_SCOPE(simd);
// 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.empty() ? 0 : data[0];
if (!data.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::WasmFeatures::FromIsolate(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
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