| // Copyright 2015 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 "src/wasm/module-decoder.h" |
| |
| #include "src/base/functional.h" |
| #include "src/base/platform/platform.h" |
| #include "src/base/template-utils.h" |
| #include "src/flags/flags.h" |
| #include "src/init/v8.h" |
| #include "src/logging/counters.h" |
| #include "src/objects/objects-inl.h" |
| #include "src/utils/ostreams.h" |
| #include "src/wasm/decoder.h" |
| #include "src/wasm/function-body-decoder-impl.h" |
| #include "src/wasm/wasm-engine.h" |
| #include "src/wasm/wasm-limits.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace wasm { |
| |
| #define TRACE(...) \ |
| do { \ |
| if (FLAG_trace_wasm_decoder) PrintF(__VA_ARGS__); \ |
| } while (false) |
| |
| namespace { |
| |
| constexpr char kNameString[] = "name"; |
| constexpr char kSourceMappingURLString[] = "sourceMappingURL"; |
| constexpr char kCompilationHintsString[] = "compilationHints"; |
| |
| template <size_t N> |
| constexpr size_t num_chars(const char (&)[N]) { |
| return N - 1; // remove null character at end. |
| } |
| |
| const char* ExternalKindName(ImportExportKindCode kind) { |
| switch (kind) { |
| case kExternalFunction: |
| return "function"; |
| case kExternalTable: |
| return "table"; |
| case kExternalMemory: |
| return "memory"; |
| case kExternalGlobal: |
| return "global"; |
| case kExternalException: |
| return "exception"; |
| } |
| return "unknown"; |
| } |
| |
| } // namespace |
| |
| const char* SectionName(SectionCode code) { |
| switch (code) { |
| case kUnknownSectionCode: |
| return "Unknown"; |
| case kTypeSectionCode: |
| return "Type"; |
| case kImportSectionCode: |
| return "Import"; |
| case kFunctionSectionCode: |
| return "Function"; |
| case kTableSectionCode: |
| return "Table"; |
| case kMemorySectionCode: |
| return "Memory"; |
| case kGlobalSectionCode: |
| return "Global"; |
| case kExportSectionCode: |
| return "Export"; |
| case kStartSectionCode: |
| return "Start"; |
| case kCodeSectionCode: |
| return "Code"; |
| case kElementSectionCode: |
| return "Element"; |
| case kDataSectionCode: |
| return "Data"; |
| case kExceptionSectionCode: |
| return "Exception"; |
| case kDataCountSectionCode: |
| return "DataCount"; |
| case kNameSectionCode: |
| return kNameString; |
| case kSourceMappingURLSectionCode: |
| return kSourceMappingURLString; |
| case kCompilationHintsSectionCode: |
| return kCompilationHintsString; |
| default: |
| return "<unknown>"; |
| } |
| } |
| |
| namespace { |
| |
| bool validate_utf8(Decoder* decoder, WireBytesRef string) { |
| return unibrow::Utf8::ValidateEncoding( |
| decoder->start() + decoder->GetBufferRelativeOffset(string.offset()), |
| string.length()); |
| } |
| |
| ValueType TypeOf(const WasmModule* module, const WasmInitExpr& expr) { |
| switch (expr.kind) { |
| case WasmInitExpr::kNone: |
| return kWasmStmt; |
| case WasmInitExpr::kGlobalIndex: |
| return expr.val.global_index < module->globals.size() |
| ? module->globals[expr.val.global_index].type |
| : kWasmStmt; |
| case WasmInitExpr::kI32Const: |
| return kWasmI32; |
| case WasmInitExpr::kI64Const: |
| return kWasmI64; |
| case WasmInitExpr::kF32Const: |
| return kWasmF32; |
| case WasmInitExpr::kF64Const: |
| return kWasmF64; |
| case WasmInitExpr::kRefNullConst: |
| return kWasmNullRef; |
| case WasmInitExpr::kRefFuncConst: |
| return kWasmFuncRef; |
| default: |
| UNREACHABLE(); |
| } |
| } |
| |
| // Reads a length-prefixed string, checking that it is within bounds. Returns |
| // the offset of the string, and the length as an out parameter. |
| WireBytesRef consume_string(Decoder* decoder, bool validate_utf8, |
| const char* name) { |
| uint32_t length = decoder->consume_u32v("string length"); |
| uint32_t offset = decoder->pc_offset(); |
| const byte* string_start = decoder->pc(); |
| // Consume bytes before validation to guarantee that the string is not oob. |
| if (length > 0) { |
| decoder->consume_bytes(length, name); |
| if (decoder->ok() && validate_utf8 && |
| !unibrow::Utf8::ValidateEncoding(string_start, length)) { |
| decoder->errorf(string_start, "%s: no valid UTF-8 string", name); |
| } |
| } |
| return {offset, decoder->failed() ? 0 : length}; |
| } |
| |
| // An iterator over the sections in a wasm binary module. |
| // Automatically skips all unknown sections. |
| class WasmSectionIterator { |
| public: |
| explicit WasmSectionIterator(Decoder* decoder) |
| : decoder_(decoder), |
| section_code_(kUnknownSectionCode), |
| section_start_(decoder->pc()), |
| section_end_(decoder->pc()) { |
| next(); |
| } |
| |
| inline bool more() const { return decoder_->ok() && decoder_->more(); } |
| |
| inline SectionCode section_code() const { return section_code_; } |
| |
| inline const byte* section_start() const { return section_start_; } |
| |
| inline uint32_t section_length() const { |
| return static_cast<uint32_t>(section_end_ - section_start_); |
| } |
| |
| inline Vector<const uint8_t> payload() const { |
| return {payload_start_, payload_length()}; |
| } |
| |
| inline const byte* payload_start() const { return payload_start_; } |
| |
| inline uint32_t payload_length() const { |
| return static_cast<uint32_t>(section_end_ - payload_start_); |
| } |
| |
| inline const byte* section_end() const { return section_end_; } |
| |
| // Advances to the next section, checking that decoding the current section |
| // stopped at {section_end_}. |
| void advance(bool move_to_section_end = false) { |
| if (move_to_section_end && decoder_->pc() < section_end_) { |
| decoder_->consume_bytes( |
| static_cast<uint32_t>(section_end_ - decoder_->pc())); |
| } |
| if (decoder_->pc() != section_end_) { |
| const char* msg = decoder_->pc() < section_end_ ? "shorter" : "longer"; |
| decoder_->errorf(decoder_->pc(), |
| "section was %s than expected size " |
| "(%u bytes expected, %zu decoded)", |
| msg, section_length(), |
| static_cast<size_t>(decoder_->pc() - section_start_)); |
| } |
| next(); |
| } |
| |
| private: |
| Decoder* decoder_; |
| SectionCode section_code_; |
| const byte* section_start_; |
| const byte* payload_start_; |
| const byte* section_end_; |
| |
| // Reads the section code/name at the current position and sets up |
| // the embedder fields. |
| void next() { |
| if (!decoder_->more()) { |
| section_code_ = kUnknownSectionCode; |
| return; |
| } |
| section_start_ = decoder_->pc(); |
| uint8_t section_code = decoder_->consume_u8("section code"); |
| // Read and check the section size. |
| uint32_t section_length = decoder_->consume_u32v("section length"); |
| |
| payload_start_ = decoder_->pc(); |
| if (decoder_->checkAvailable(section_length)) { |
| // Get the limit of the section within the module. |
| section_end_ = payload_start_ + section_length; |
| } else { |
| // The section would extend beyond the end of the module. |
| section_end_ = payload_start_; |
| } |
| |
| if (section_code == kUnknownSectionCode) { |
| // Check for the known "name", "sourceMappingURL", or "compilationHints" |
| // section. |
| section_code = |
| ModuleDecoder::IdentifyUnknownSection(decoder_, section_end_); |
| // As a side effect, the above function will forward the decoder to after |
| // the identifier string. |
| payload_start_ = decoder_->pc(); |
| } else if (!IsValidSectionCode(section_code)) { |
| decoder_->errorf(decoder_->pc(), "unknown section code #0x%02x", |
| section_code); |
| section_code = kUnknownSectionCode; |
| } |
| section_code_ = decoder_->failed() ? kUnknownSectionCode |
| : static_cast<SectionCode>(section_code); |
| |
| if (section_code_ == kUnknownSectionCode && section_end_ > decoder_->pc()) { |
| // skip to the end of the unknown section. |
| uint32_t remaining = static_cast<uint32_t>(section_end_ - decoder_->pc()); |
| decoder_->consume_bytes(remaining, "section payload"); |
| } |
| } |
| }; |
| |
| } // namespace |
| |
| // The main logic for decoding the bytes of a module. |
| class ModuleDecoderImpl : public Decoder { |
| public: |
| explicit ModuleDecoderImpl(const WasmFeatures& enabled, ModuleOrigin origin) |
| : Decoder(nullptr, nullptr), |
| enabled_features_(enabled), |
| origin_(FLAG_assume_asmjs_origin ? kAsmJsSloppyOrigin : origin) {} |
| |
| ModuleDecoderImpl(const WasmFeatures& enabled, const byte* module_start, |
| const byte* module_end, ModuleOrigin origin) |
| : Decoder(module_start, module_end), |
| enabled_features_(enabled), |
| origin_(FLAG_assume_asmjs_origin ? kAsmJsSloppyOrigin : origin) { |
| if (end_ < start_) { |
| error(start_, "end is less than start"); |
| end_ = start_; |
| } |
| } |
| |
| void onFirstError() override { |
| pc_ = end_; // On error, terminate section decoding loop. |
| } |
| |
| void DumpModule(const Vector<const byte> module_bytes) { |
| #if !defined(STARBOARD) |
| std::string path; |
| if (FLAG_dump_wasm_module_path) { |
| path = FLAG_dump_wasm_module_path; |
| if (path.size() && |
| !base::OS::isDirectorySeparator(path[path.size() - 1])) { |
| path += base::OS::DirectorySeparator(); |
| } |
| } |
| // File are named `HASH.{ok,failed}.wasm`. |
| size_t hash = base::hash_range(module_bytes.begin(), module_bytes.end()); |
| EmbeddedVector<char, 32> buf; |
| SNPrintF(buf, "%016zx.%s.wasm", hash, ok() ? "ok" : "failed"); |
| std::string name(buf.begin()); |
| if (FILE* wasm_file = base::OS::FOpen((path + name).c_str(), "wb")) { |
| if (fwrite(module_bytes.begin(), module_bytes.length(), 1, wasm_file) != |
| 1) { |
| OFStream os(stderr); |
| os << "Error while dumping wasm file" << std::endl; |
| } |
| fclose(wasm_file); |
| } |
| #endif // !defined(STARBOARD) |
| } |
| |
| void StartDecoding(Counters* counters, AccountingAllocator* allocator) { |
| CHECK_NULL(module_); |
| SetCounters(counters); |
| module_.reset( |
| new WasmModule(base::make_unique<Zone>(allocator, "signatures"))); |
| module_->initial_pages = 0; |
| module_->maximum_pages = 0; |
| module_->mem_export = false; |
| module_->origin = origin_; |
| } |
| |
| void DecodeModuleHeader(Vector<const uint8_t> bytes, uint8_t offset) { |
| if (failed()) return; |
| Reset(bytes, offset); |
| |
| const byte* pos = pc_; |
| uint32_t magic_word = consume_u32("wasm magic"); |
| #define BYTES(x) (x & 0xFF), (x >> 8) & 0xFF, (x >> 16) & 0xFF, (x >> 24) & 0xFF |
| if (magic_word != kWasmMagic) { |
| errorf(pos, |
| "expected magic word %02x %02x %02x %02x, " |
| "found %02x %02x %02x %02x", |
| BYTES(kWasmMagic), BYTES(magic_word)); |
| } |
| |
| pos = pc_; |
| { |
| uint32_t magic_version = consume_u32("wasm version"); |
| if (magic_version != kWasmVersion) { |
| errorf(pos, |
| "expected version %02x %02x %02x %02x, " |
| "found %02x %02x %02x %02x", |
| BYTES(kWasmVersion), BYTES(magic_version)); |
| } |
| } |
| #undef BYTES |
| } |
| |
| bool CheckSectionOrder(SectionCode section_code, |
| SectionCode prev_section_code, |
| SectionCode next_section_code) { |
| if (next_ordered_section_ > next_section_code) { |
| errorf(pc(), "The %s section must appear before the %s section", |
| SectionName(section_code), SectionName(next_section_code)); |
| return false; |
| } |
| if (next_ordered_section_ <= prev_section_code) { |
| next_ordered_section_ = prev_section_code + 1; |
| } |
| return true; |
| } |
| |
| bool CheckUnorderedSection(SectionCode section_code) { |
| if (has_seen_unordered_section(section_code)) { |
| errorf(pc(), "Multiple %s sections not allowed", |
| SectionName(section_code)); |
| return false; |
| } |
| set_seen_unordered_section(section_code); |
| return true; |
| } |
| |
| void DecodeSection(SectionCode section_code, Vector<const uint8_t> bytes, |
| uint32_t offset, bool verify_functions = true) { |
| if (failed()) return; |
| Reset(bytes, offset); |
| TRACE("Section: %s\n", SectionName(section_code)); |
| TRACE("Decode Section %p - %p\n", bytes.begin(), bytes.end()); |
| |
| // Check if the section is out-of-order. |
| if (section_code < next_ordered_section_ && |
| section_code < kFirstUnorderedSection) { |
| errorf(pc(), "unexpected section <%s>", SectionName(section_code)); |
| return; |
| } |
| |
| switch (section_code) { |
| case kUnknownSectionCode: |
| break; |
| case kDataCountSectionCode: |
| if (!CheckUnorderedSection(section_code)) return; |
| if (!CheckSectionOrder(section_code, kElementSectionCode, |
| kCodeSectionCode)) |
| return; |
| break; |
| case kExceptionSectionCode: |
| if (!CheckUnorderedSection(section_code)) return; |
| if (!CheckSectionOrder(section_code, kGlobalSectionCode, |
| kExportSectionCode)) |
| return; |
| break; |
| case kNameSectionCode: |
| // TODO(titzer): report out of place name section as a warning. |
| // Be lenient with placement of name section. All except first |
| // occurrence are ignored. |
| case kSourceMappingURLSectionCode: |
| // sourceMappingURL is a custom section and currently can occur anywhere |
| // in the module. In case of multiple sourceMappingURL sections, all |
| // except the first occurrence are ignored. |
| case kCompilationHintsSectionCode: |
| // TODO(frgossen): report out of place compilation hints section as a |
| // warning. |
| // Be lenient with placement of compilation hints section. All except |
| // first occurrence after function section and before code section are |
| // ignored. |
| break; |
| default: |
| next_ordered_section_ = section_code + 1; |
| break; |
| } |
| |
| switch (section_code) { |
| case kUnknownSectionCode: |
| break; |
| case kTypeSectionCode: |
| DecodeTypeSection(); |
| break; |
| case kImportSectionCode: |
| DecodeImportSection(); |
| break; |
| case kFunctionSectionCode: |
| DecodeFunctionSection(); |
| break; |
| case kTableSectionCode: |
| DecodeTableSection(); |
| break; |
| case kMemorySectionCode: |
| DecodeMemorySection(); |
| break; |
| case kGlobalSectionCode: |
| DecodeGlobalSection(); |
| break; |
| case kExportSectionCode: |
| DecodeExportSection(); |
| break; |
| case kStartSectionCode: |
| DecodeStartSection(); |
| break; |
| case kCodeSectionCode: |
| DecodeCodeSection(verify_functions); |
| break; |
| case kElementSectionCode: |
| DecodeElementSection(); |
| break; |
| case kDataSectionCode: |
| DecodeDataSection(); |
| break; |
| case kNameSectionCode: |
| DecodeNameSection(); |
| break; |
| case kSourceMappingURLSectionCode: |
| DecodeSourceMappingURLSection(); |
| break; |
| case kCompilationHintsSectionCode: |
| if (enabled_features_.compilation_hints) { |
| DecodeCompilationHintsSection(); |
| } else { |
| // Ignore this section when feature was disabled. It is an optional |
| // custom section anyways. |
| consume_bytes(static_cast<uint32_t>(end_ - start_), nullptr); |
| } |
| break; |
| case kDataCountSectionCode: |
| if (enabled_features_.bulk_memory) { |
| DecodeDataCountSection(); |
| } else { |
| errorf(pc(), "unexpected section <%s>", SectionName(section_code)); |
| } |
| break; |
| case kExceptionSectionCode: |
| if (enabled_features_.eh) { |
| DecodeExceptionSection(); |
| } else { |
| errorf(pc(), "unexpected section <%s>", SectionName(section_code)); |
| } |
| break; |
| default: |
| errorf(pc(), "unexpected section <%s>", SectionName(section_code)); |
| return; |
| } |
| |
| if (pc() != bytes.end()) { |
| const char* msg = pc() < bytes.end() ? "shorter" : "longer"; |
| errorf(pc(), |
| "section was %s than expected size " |
| "(%zu bytes expected, %zu decoded)", |
| msg, bytes.size(), static_cast<size_t>(pc() - bytes.begin())); |
| } |
| } |
| |
| void DecodeTypeSection() { |
| uint32_t signatures_count = consume_count("types count", kV8MaxWasmTypes); |
| module_->signatures.reserve(signatures_count); |
| for (uint32_t i = 0; ok() && i < signatures_count; ++i) { |
| TRACE("DecodeSignature[%d] module+%d\n", i, |
| static_cast<int>(pc_ - start_)); |
| FunctionSig* s = consume_sig(module_->signature_zone.get()); |
| module_->signatures.push_back(s); |
| uint32_t id = s ? module_->signature_map.FindOrInsert(*s) : 0; |
| module_->signature_ids.push_back(id); |
| } |
| module_->signature_map.Freeze(); |
| } |
| |
| void DecodeImportSection() { |
| uint32_t import_table_count = |
| consume_count("imports count", kV8MaxWasmImports); |
| module_->import_table.reserve(import_table_count); |
| for (uint32_t i = 0; ok() && i < import_table_count; ++i) { |
| TRACE("DecodeImportTable[%d] module+%d\n", i, |
| static_cast<int>(pc_ - start_)); |
| |
| module_->import_table.push_back({ |
| {0, 0}, // module_name |
| {0, 0}, // field_name |
| kExternalFunction, // kind |
| 0 // index |
| }); |
| WasmImport* import = &module_->import_table.back(); |
| const byte* pos = pc_; |
| import->module_name = consume_string(this, true, "module name"); |
| import->field_name = consume_string(this, true, "field name"); |
| import->kind = |
| static_cast<ImportExportKindCode>(consume_u8("import kind")); |
| switch (import->kind) { |
| case kExternalFunction: { |
| // ===== Imported function =========================================== |
| import->index = static_cast<uint32_t>(module_->functions.size()); |
| module_->num_imported_functions++; |
| module_->functions.push_back({nullptr, // sig |
| import->index, // func_index |
| 0, // sig_index |
| {0, 0}, // code |
| true, // imported |
| false}); // exported |
| WasmFunction* function = &module_->functions.back(); |
| function->sig_index = |
| consume_sig_index(module_.get(), &function->sig); |
| break; |
| } |
| case kExternalTable: { |
| // ===== Imported table ============================================== |
| if (!AddTable(module_.get())) break; |
| import->index = static_cast<uint32_t>(module_->tables.size()); |
| module_->num_imported_tables++; |
| module_->tables.emplace_back(); |
| WasmTable* table = &module_->tables.back(); |
| table->imported = true; |
| ValueType type = consume_reference_type(); |
| if (!enabled_features_.anyref) { |
| if (type != kWasmFuncRef) { |
| error(pc_ - 1, "invalid table type"); |
| break; |
| } |
| } |
| table->type = type; |
| uint8_t flags = validate_table_flags("element count"); |
| consume_resizable_limits( |
| "element count", "elements", FLAG_wasm_max_table_size, |
| &table->initial_size, &table->has_maximum_size, |
| FLAG_wasm_max_table_size, &table->maximum_size, flags); |
| break; |
| } |
| case kExternalMemory: { |
| // ===== Imported memory ============================================= |
| if (!AddMemory(module_.get())) break; |
| uint8_t flags = validate_memory_flags(&module_->has_shared_memory); |
| consume_resizable_limits( |
| "memory", "pages", kSpecMaxWasmMemoryPages, |
| &module_->initial_pages, &module_->has_maximum_pages, |
| kSpecMaxWasmMemoryPages, &module_->maximum_pages, flags); |
| break; |
| } |
| case kExternalGlobal: { |
| // ===== Imported global ============================================= |
| import->index = static_cast<uint32_t>(module_->globals.size()); |
| module_->globals.push_back( |
| {kWasmStmt, false, WasmInitExpr(), {0}, true, false}); |
| WasmGlobal* global = &module_->globals.back(); |
| global->type = consume_value_type(); |
| global->mutability = consume_mutability(); |
| if (global->mutability) { |
| module_->num_imported_mutable_globals++; |
| } |
| break; |
| } |
| case kExternalException: { |
| // ===== Imported exception ========================================== |
| if (!enabled_features_.eh) { |
| errorf(pos, "unknown import kind 0x%02x", import->kind); |
| break; |
| } |
| import->index = static_cast<uint32_t>(module_->exceptions.size()); |
| WasmExceptionSig* exception_sig = nullptr; |
| consume_exception_attribute(); // Attribute ignored for now. |
| consume_exception_sig_index(module_.get(), &exception_sig); |
| module_->exceptions.emplace_back(exception_sig); |
| break; |
| } |
| default: |
| errorf(pos, "unknown import kind 0x%02x", import->kind); |
| break; |
| } |
| } |
| } |
| |
| void DecodeFunctionSection() { |
| uint32_t functions_count = |
| consume_count("functions count", kV8MaxWasmFunctions); |
| auto counter = |
| SELECT_WASM_COUNTER(GetCounters(), origin_, wasm_functions_per, module); |
| counter->AddSample(static_cast<int>(functions_count)); |
| DCHECK_EQ(module_->functions.size(), module_->num_imported_functions); |
| uint32_t total_function_count = |
| module_->num_imported_functions + functions_count; |
| module_->functions.reserve(total_function_count); |
| module_->num_declared_functions = functions_count; |
| for (uint32_t i = 0; i < functions_count; ++i) { |
| uint32_t func_index = static_cast<uint32_t>(module_->functions.size()); |
| module_->functions.push_back({nullptr, // sig |
| func_index, // func_index |
| 0, // sig_index |
| {0, 0}, // code |
| false, // imported |
| false}); // exported |
| WasmFunction* function = &module_->functions.back(); |
| function->sig_index = consume_sig_index(module_.get(), &function->sig); |
| if (!ok()) return; |
| } |
| DCHECK_EQ(module_->functions.size(), total_function_count); |
| } |
| |
| void DecodeTableSection() { |
| // TODO(ahaas): Set the correct limit to {kV8MaxWasmTables} once the |
| // implementation of AnyRef landed. |
| uint32_t max_count = enabled_features_.anyref ? 100000 : kV8MaxWasmTables; |
| uint32_t table_count = consume_count("table count", max_count); |
| |
| for (uint32_t i = 0; ok() && i < table_count; i++) { |
| if (!AddTable(module_.get())) break; |
| module_->tables.emplace_back(); |
| WasmTable* table = &module_->tables.back(); |
| table->type = consume_reference_type(); |
| uint8_t flags = validate_table_flags("table elements"); |
| consume_resizable_limits( |
| "table elements", "elements", FLAG_wasm_max_table_size, |
| &table->initial_size, &table->has_maximum_size, |
| FLAG_wasm_max_table_size, &table->maximum_size, flags); |
| } |
| } |
| |
| void DecodeMemorySection() { |
| uint32_t memory_count = consume_count("memory count", kV8MaxWasmMemories); |
| |
| for (uint32_t i = 0; ok() && i < memory_count; i++) { |
| if (!AddMemory(module_.get())) break; |
| uint8_t flags = validate_memory_flags(&module_->has_shared_memory); |
| consume_resizable_limits( |
| "memory", "pages", kSpecMaxWasmMemoryPages, &module_->initial_pages, |
| &module_->has_maximum_pages, kSpecMaxWasmMemoryPages, |
| &module_->maximum_pages, flags); |
| } |
| } |
| |
| void DecodeGlobalSection() { |
| uint32_t globals_count = consume_count("globals count", kV8MaxWasmGlobals); |
| uint32_t imported_globals = static_cast<uint32_t>(module_->globals.size()); |
| module_->globals.reserve(imported_globals + globals_count); |
| for (uint32_t i = 0; ok() && i < globals_count; ++i) { |
| TRACE("DecodeGlobal[%d] module+%d\n", i, static_cast<int>(pc_ - start_)); |
| // Add an uninitialized global and pass a pointer to it. |
| module_->globals.push_back( |
| {kWasmStmt, false, WasmInitExpr(), {0}, false, false}); |
| WasmGlobal* global = &module_->globals.back(); |
| DecodeGlobalInModule(module_.get(), i + imported_globals, global); |
| } |
| if (ok()) CalculateGlobalOffsets(module_.get()); |
| } |
| |
| void DecodeExportSection() { |
| uint32_t export_table_count = |
| consume_count("exports count", kV8MaxWasmExports); |
| module_->export_table.reserve(export_table_count); |
| for (uint32_t i = 0; ok() && i < export_table_count; ++i) { |
| TRACE("DecodeExportTable[%d] module+%d\n", i, |
| static_cast<int>(pc_ - start_)); |
| |
| module_->export_table.push_back({ |
| {0, 0}, // name |
| kExternalFunction, // kind |
| 0 // index |
| }); |
| WasmExport* exp = &module_->export_table.back(); |
| |
| exp->name = consume_string(this, true, "field name"); |
| |
| const byte* pos = pc(); |
| exp->kind = static_cast<ImportExportKindCode>(consume_u8("export kind")); |
| switch (exp->kind) { |
| case kExternalFunction: { |
| WasmFunction* func = nullptr; |
| exp->index = |
| consume_func_index(module_.get(), &func, "export function index"); |
| module_->num_exported_functions++; |
| if (func) func->exported = true; |
| break; |
| } |
| case kExternalTable: { |
| WasmTable* table = nullptr; |
| exp->index = consume_table_index(module_.get(), &table); |
| if (table) table->exported = true; |
| break; |
| } |
| case kExternalMemory: { |
| uint32_t index = consume_u32v("memory index"); |
| // TODO(titzer): This should become more regular |
| // once we support multiple memories. |
| if (!module_->has_memory || index != 0) { |
| error("invalid memory index != 0"); |
| } |
| module_->mem_export = true; |
| break; |
| } |
| case kExternalGlobal: { |
| WasmGlobal* global = nullptr; |
| exp->index = consume_global_index(module_.get(), &global); |
| if (global) { |
| global->exported = true; |
| } |
| break; |
| } |
| case kExternalException: { |
| if (!enabled_features_.eh) { |
| errorf(pos, "invalid export kind 0x%02x", exp->kind); |
| break; |
| } |
| WasmException* exception = nullptr; |
| exp->index = consume_exception_index(module_.get(), &exception); |
| break; |
| } |
| default: |
| errorf(pos, "invalid export kind 0x%02x", exp->kind); |
| break; |
| } |
| } |
| // Check for duplicate exports (except for asm.js). |
| if (ok() && origin_ == kWasmOrigin && module_->export_table.size() > 1) { |
| std::vector<WasmExport> sorted_exports(module_->export_table); |
| |
| auto cmp_less = [this](const WasmExport& a, const WasmExport& b) { |
| // Return true if a < b. |
| if (a.name.length() != b.name.length()) { |
| return a.name.length() < b.name.length(); |
| } |
| const byte* left = start() + GetBufferRelativeOffset(a.name.offset()); |
| const byte* right = start() + GetBufferRelativeOffset(b.name.offset()); |
| return memcmp(left, right, a.name.length()) < 0; |
| }; |
| std::stable_sort(sorted_exports.begin(), sorted_exports.end(), cmp_less); |
| |
| auto it = sorted_exports.begin(); |
| WasmExport* last = &*it++; |
| for (auto end = sorted_exports.end(); it != end; last = &*it++) { |
| DCHECK(!cmp_less(*it, *last)); // Vector must be sorted. |
| if (!cmp_less(*last, *it)) { |
| const byte* pc = start() + GetBufferRelativeOffset(it->name.offset()); |
| TruncatedUserString<> name(pc, it->name.length()); |
| errorf(pc, "Duplicate export name '%.*s' for %s %d and %s %d", |
| name.length(), name.start(), ExternalKindName(last->kind), |
| last->index, ExternalKindName(it->kind), it->index); |
| break; |
| } |
| } |
| } |
| } |
| |
| void DecodeStartSection() { |
| WasmFunction* func; |
| const byte* pos = pc_; |
| module_->start_function_index = |
| consume_func_index(module_.get(), &func, "start function index"); |
| if (func && |
| (func->sig->parameter_count() > 0 || func->sig->return_count() > 0)) { |
| error(pos, "invalid start function: non-zero parameter or return count"); |
| } |
| } |
| |
| void DecodeElementSection() { |
| uint32_t element_count = |
| consume_count("element count", FLAG_wasm_max_table_size); |
| |
| if (element_count > 0 && module_->tables.size() == 0) { |
| error(pc_, "The element section requires a table"); |
| } |
| for (uint32_t i = 0; ok() && i < element_count; ++i) { |
| const byte* pos = pc(); |
| |
| bool is_active; |
| uint32_t table_index; |
| WasmInitExpr offset; |
| consume_segment_header("table index", &is_active, &table_index, &offset); |
| if (failed()) return; |
| |
| if (is_active) { |
| if (table_index >= module_->tables.size()) { |
| errorf(pos, "out of bounds table index %u", table_index); |
| break; |
| } |
| if (!ValueTypes::IsSubType(kWasmFuncRef, |
| module_->tables[table_index].type)) { |
| errorf(pos, |
| "Invalid element segment. Table %u is not of type FuncRef", |
| table_index); |
| break; |
| } |
| } else { |
| ValueType type = consume_reference_type(); |
| if (!ValueTypes::IsSubType(kWasmFuncRef, type)) { |
| error(pc_ - 1, "invalid element segment type"); |
| break; |
| } |
| } |
| |
| uint32_t num_elem = |
| consume_count("number of elements", max_table_init_entries()); |
| if (is_active) { |
| module_->elem_segments.emplace_back(table_index, offset); |
| } else { |
| module_->elem_segments.emplace_back(); |
| } |
| |
| WasmElemSegment* init = &module_->elem_segments.back(); |
| for (uint32_t j = 0; j < num_elem; j++) { |
| uint32_t index = is_active ? consume_element_func_index() |
| : consume_passive_element(); |
| if (failed()) break; |
| init->entries.push_back(index); |
| } |
| } |
| } |
| |
| void DecodeCodeSection(bool verify_functions) { |
| uint32_t pos = pc_offset(); |
| uint32_t functions_count = consume_u32v("functions count"); |
| CheckFunctionsCount(functions_count, pos); |
| for (uint32_t i = 0; ok() && i < functions_count; ++i) { |
| const byte* pos = pc(); |
| uint32_t size = consume_u32v("body size"); |
| if (size > kV8MaxWasmFunctionSize) { |
| errorf(pos, "size %u > maximum function size %zu", size, |
| kV8MaxWasmFunctionSize); |
| return; |
| } |
| uint32_t offset = pc_offset(); |
| consume_bytes(size, "function body"); |
| if (failed()) break; |
| DecodeFunctionBody(i, size, offset, verify_functions); |
| } |
| } |
| |
| bool CheckFunctionsCount(uint32_t functions_count, uint32_t offset) { |
| if (functions_count != module_->num_declared_functions) { |
| Reset(nullptr, nullptr, offset); |
| errorf(nullptr, "function body count %u mismatch (%u expected)", |
| functions_count, module_->num_declared_functions); |
| return false; |
| } |
| return true; |
| } |
| |
| void DecodeFunctionBody(uint32_t index, uint32_t length, uint32_t offset, |
| bool verify_functions) { |
| WasmFunction* function = |
| &module_->functions[index + module_->num_imported_functions]; |
| function->code = {offset, length}; |
| if (verify_functions) { |
| ModuleWireBytes bytes(start_, end_); |
| VerifyFunctionBody(module_->signature_zone->allocator(), |
| index + module_->num_imported_functions, bytes, |
| module_.get(), function); |
| } |
| } |
| |
| bool CheckDataSegmentsCount(uint32_t data_segments_count) { |
| if (has_seen_unordered_section(kDataCountSectionCode) && |
| data_segments_count != module_->num_declared_data_segments) { |
| errorf(pc(), "data segments count %u mismatch (%u expected)", |
| data_segments_count, module_->num_declared_data_segments); |
| return false; |
| } |
| return true; |
| } |
| |
| void DecodeDataSection() { |
| uint32_t data_segments_count = |
| consume_count("data segments count", kV8MaxWasmDataSegments); |
| if (!CheckDataSegmentsCount(data_segments_count)) return; |
| |
| module_->data_segments.reserve(data_segments_count); |
| for (uint32_t i = 0; ok() && i < data_segments_count; ++i) { |
| const byte* pos = pc(); |
| if (!module_->has_memory) { |
| error("cannot load data without memory"); |
| break; |
| } |
| TRACE("DecodeDataSegment[%d] module+%d\n", i, |
| static_cast<int>(pc_ - start_)); |
| |
| bool is_active; |
| uint32_t memory_index; |
| WasmInitExpr dest_addr; |
| consume_segment_header("memory index", &is_active, &memory_index, |
| &dest_addr); |
| if (failed()) break; |
| |
| if (is_active && memory_index != 0) { |
| errorf(pos, "illegal memory index %u != 0", memory_index); |
| break; |
| } |
| |
| uint32_t source_length = consume_u32v("source size"); |
| uint32_t source_offset = pc_offset(); |
| |
| if (is_active) { |
| module_->data_segments.emplace_back(dest_addr); |
| } else { |
| module_->data_segments.emplace_back(); |
| } |
| |
| WasmDataSegment* segment = &module_->data_segments.back(); |
| |
| consume_bytes(source_length, "segment data"); |
| if (failed()) break; |
| |
| segment->source = {source_offset, source_length}; |
| } |
| } |
| |
| void DecodeNameSection() { |
| // TODO(titzer): find a way to report name errors as warnings. |
| // Ignore all but the first occurrence of name section. |
| if (!has_seen_unordered_section(kNameSectionCode)) { |
| set_seen_unordered_section(kNameSectionCode); |
| // Use an inner decoder so that errors don't fail the outer decoder. |
| Decoder inner(start_, pc_, end_, buffer_offset_); |
| // Decode all name subsections. |
| // Be lenient with their order. |
| while (inner.ok() && inner.more()) { |
| uint8_t name_type = inner.consume_u8("name type"); |
| if (name_type & 0x80) inner.error("name type if not varuint7"); |
| |
| uint32_t name_payload_len = inner.consume_u32v("name payload length"); |
| if (!inner.checkAvailable(name_payload_len)) break; |
| |
| // Decode module name, ignore the rest. |
| // Function and local names will be decoded when needed. |
| if (name_type == NameSectionKindCode::kModule) { |
| WireBytesRef name = consume_string(&inner, false, "module name"); |
| if (inner.ok() && validate_utf8(&inner, name)) module_->name = name; |
| } else { |
| inner.consume_bytes(name_payload_len, "name subsection payload"); |
| } |
| } |
| } |
| // Skip the whole names section in the outer decoder. |
| consume_bytes(static_cast<uint32_t>(end_ - start_), nullptr); |
| } |
| |
| void DecodeSourceMappingURLSection() { |
| Decoder inner(start_, pc_, end_, buffer_offset_); |
| WireBytesRef url = wasm::consume_string(&inner, true, "module name"); |
| if (inner.ok() && |
| !has_seen_unordered_section(kSourceMappingURLSectionCode)) { |
| const byte* url_start = |
| inner.start() + inner.GetBufferRelativeOffset(url.offset()); |
| module_->source_map_url.assign(reinterpret_cast<const char*>(url_start), |
| url.length()); |
| set_seen_unordered_section(kSourceMappingURLSectionCode); |
| } |
| consume_bytes(static_cast<uint32_t>(end_ - start_), nullptr); |
| } |
| |
| void DecodeCompilationHintsSection() { |
| TRACE("DecodeCompilationHints module+%d\n", static_cast<int>(pc_ - start_)); |
| |
| // TODO(frgossen): Find a way to report compilation hint errors as warnings. |
| // All except first occurrence after function section and before code |
| // section are ignored. |
| const bool before_function_section = |
| next_ordered_section_ <= kFunctionSectionCode; |
| const bool after_code_section = next_ordered_section_ > kCodeSectionCode; |
| if (before_function_section || after_code_section || |
| has_seen_unordered_section(kCompilationHintsSectionCode)) { |
| return; |
| } |
| set_seen_unordered_section(kCompilationHintsSectionCode); |
| |
| // TODO(frgossen) Propagate errors to outer decoder in experimental phase. |
| // We should use an inner decoder later and propagate its errors as |
| // warnings. |
| Decoder& decoder = *this; |
| // Decoder decoder(start_, pc_, end_, buffer_offset_); |
| |
| // Ensure exactly one compilation hint per function. |
| uint32_t hint_count = decoder.consume_u32v("compilation hint count"); |
| if (hint_count != module_->num_declared_functions) { |
| decoder.errorf(decoder.pc(), "Expected %u compilation hints (%u found)", |
| module_->num_declared_functions, hint_count); |
| } |
| |
| // Decode sequence of compilation hints. |
| if (decoder.ok()) { |
| module_->compilation_hints.reserve(hint_count); |
| } |
| for (uint32_t i = 0; decoder.ok() && i < hint_count; i++) { |
| TRACE("DecodeCompilationHints[%d] module+%d\n", i, |
| static_cast<int>(pc_ - start_)); |
| |
| // Compilation hints are encoded in one byte each. |
| // +-------+----------+---------------+----------+ |
| // | 2 bit | 2 bit | 2 bit | 2 bit | |
| // | ... | Top tier | Baseline tier | Strategy | |
| // +-------+----------+---------------+----------+ |
| uint8_t hint_byte = decoder.consume_u8("compilation hint"); |
| if (!decoder.ok()) break; |
| |
| // Decode compilation hint. |
| WasmCompilationHint hint; |
| hint.strategy = |
| static_cast<WasmCompilationHintStrategy>(hint_byte & 0x03); |
| hint.baseline_tier = |
| static_cast<WasmCompilationHintTier>(hint_byte >> 2 & 0x3); |
| hint.top_tier = |
| static_cast<WasmCompilationHintTier>(hint_byte >> 4 & 0x3); |
| |
| // Ensure that the top tier never downgrades a compilation result. |
| // If baseline and top tier are the same compilation will be invoked only |
| // once. |
| if (hint.top_tier < hint.baseline_tier && |
| hint.top_tier != WasmCompilationHintTier::kDefault) { |
| decoder.errorf(decoder.pc(), |
| "Invalid compilation hint %#x (forbidden downgrade)", |
| hint_byte); |
| } |
| |
| // Happily accept compilation hint. |
| if (decoder.ok()) { |
| module_->compilation_hints.push_back(std::move(hint)); |
| } |
| } |
| |
| // If section was invalid reset compilation hints. |
| if (decoder.failed()) { |
| module_->compilation_hints.clear(); |
| } |
| |
| // @TODO(frgossen) Skip the whole compilation hints section in the outer |
| // decoder if inner decoder was used. |
| // consume_bytes(static_cast<uint32_t>(end_ - start_), nullptr); |
| } |
| |
| void DecodeDataCountSection() { |
| module_->num_declared_data_segments = |
| consume_count("data segments count", kV8MaxWasmDataSegments); |
| } |
| |
| void DecodeExceptionSection() { |
| uint32_t exception_count = |
| consume_count("exception count", kV8MaxWasmExceptions); |
| for (uint32_t i = 0; ok() && i < exception_count; ++i) { |
| TRACE("DecodeException[%d] module+%d\n", i, |
| static_cast<int>(pc_ - start_)); |
| WasmExceptionSig* exception_sig = nullptr; |
| consume_exception_attribute(); // Attribute ignored for now. |
| consume_exception_sig_index(module_.get(), &exception_sig); |
| module_->exceptions.emplace_back(exception_sig); |
| } |
| } |
| |
| bool CheckMismatchedCounts() { |
| // The declared vs. defined function count is normally checked when |
| // decoding the code section, but we have to check it here too in case the |
| // code section is absent. |
| if (module_->num_declared_functions != 0) { |
| DCHECK_LT(module_->num_imported_functions, module_->functions.size()); |
| // We know that the code section has been decoded if the first |
| // non-imported function has its code set. |
| if (!module_->functions[module_->num_imported_functions].code.is_set()) { |
| errorf(pc(), "function count is %u, but code section is absent", |
| module_->num_declared_functions); |
| return false; |
| } |
| } |
| // Perform a similar check for the DataCount and Data sections, where data |
| // segments are declared but the Data section is absent. |
| if (!CheckDataSegmentsCount( |
| static_cast<uint32_t>(module_->data_segments.size()))) { |
| return false; |
| } |
| return true; |
| } |
| |
| ModuleResult FinishDecoding(bool verify_functions = true) { |
| if (ok() && CheckMismatchedCounts()) { |
| CalculateGlobalOffsets(module_.get()); |
| } |
| ModuleResult result = toResult(std::move(module_)); |
| if (verify_functions && result.ok() && intermediate_error_.has_error()) { |
| // Copy error message and location. |
| return ModuleResult{std::move(intermediate_error_)}; |
| } |
| return result; |
| } |
| |
| // Decodes an entire module. |
| ModuleResult DecodeModule(Counters* counters, AccountingAllocator* allocator, |
| bool verify_functions = true) { |
| StartDecoding(counters, allocator); |
| uint32_t offset = 0; |
| Vector<const byte> orig_bytes(start(), end() - start()); |
| DecodeModuleHeader(VectorOf(start(), end() - start()), offset); |
| if (failed()) { |
| return FinishDecoding(verify_functions); |
| } |
| // Size of the module header. |
| offset += 8; |
| Decoder decoder(start_ + offset, end_, offset); |
| |
| WasmSectionIterator section_iter(&decoder); |
| |
| while (ok() && section_iter.more()) { |
| // Shift the offset by the section header length |
| offset += section_iter.payload_start() - section_iter.section_start(); |
| if (section_iter.section_code() != SectionCode::kUnknownSectionCode) { |
| DecodeSection(section_iter.section_code(), section_iter.payload(), |
| offset, verify_functions); |
| } |
| // Shift the offset by the remaining section payload |
| offset += section_iter.payload_length(); |
| section_iter.advance(true); |
| } |
| |
| if (FLAG_dump_wasm_module) DumpModule(orig_bytes); |
| |
| if (decoder.failed()) { |
| return decoder.toResult<std::unique_ptr<WasmModule>>(nullptr); |
| } |
| |
| return FinishDecoding(verify_functions); |
| } |
| |
| // Decodes a single anonymous function starting at {start_}. |
| FunctionResult DecodeSingleFunction(Zone* zone, |
| const ModuleWireBytes& wire_bytes, |
| const WasmModule* module, |
| std::unique_ptr<WasmFunction> function) { |
| pc_ = start_; |
| function->sig = consume_sig(zone); |
| function->code = {off(pc_), static_cast<uint32_t>(end_ - pc_)}; |
| |
| if (ok()) |
| VerifyFunctionBody(zone->allocator(), 0, wire_bytes, module, |
| function.get()); |
| |
| if (intermediate_error_.has_error()) { |
| return FunctionResult{std::move(intermediate_error_)}; |
| } |
| |
| return FunctionResult(std::move(function)); |
| } |
| |
| // Decodes a single function signature at {start}. |
| FunctionSig* DecodeFunctionSignature(Zone* zone, const byte* start) { |
| pc_ = start; |
| FunctionSig* result = consume_sig(zone); |
| return ok() ? result : nullptr; |
| } |
| |
| WasmInitExpr DecodeInitExpr(const byte* start) { |
| pc_ = start; |
| return consume_init_expr(nullptr, kWasmStmt); |
| } |
| |
| const std::shared_ptr<WasmModule>& shared_module() const { return module_; } |
| |
| Counters* GetCounters() const { |
| DCHECK_NOT_NULL(counters_); |
| return counters_; |
| } |
| |
| void SetCounters(Counters* counters) { |
| DCHECK_NULL(counters_); |
| counters_ = counters; |
| } |
| |
| private: |
| const WasmFeatures enabled_features_; |
| std::shared_ptr<WasmModule> module_; |
| Counters* counters_ = nullptr; |
| // The type section is the first section in a module. |
| uint8_t next_ordered_section_ = kFirstSectionInModule; |
| // We store next_ordered_section_ as uint8_t instead of SectionCode so that |
| // we can increment it. This static_assert should make sure that SectionCode |
| // does not get bigger than uint8_t accidentially. |
| static_assert(sizeof(ModuleDecoderImpl::next_ordered_section_) == |
| sizeof(SectionCode), |
| "type mismatch"); |
| uint32_t seen_unordered_sections_ = 0; |
| static_assert(kBitsPerByte * |
| sizeof(ModuleDecoderImpl::seen_unordered_sections_) > |
| kLastKnownModuleSection, |
| "not enough bits"); |
| WasmError intermediate_error_; |
| ModuleOrigin origin_; |
| |
| bool has_seen_unordered_section(SectionCode section_code) { |
| return seen_unordered_sections_ & (1 << section_code); |
| } |
| |
| void set_seen_unordered_section(SectionCode section_code) { |
| seen_unordered_sections_ |= 1 << section_code; |
| } |
| |
| uint32_t off(const byte* ptr) { |
| return static_cast<uint32_t>(ptr - start_) + buffer_offset_; |
| } |
| |
| bool AddTable(WasmModule* module) { |
| if (enabled_features_.anyref) return true; |
| if (module->tables.size() > 0) { |
| error("At most one table is supported"); |
| return false; |
| } else { |
| return true; |
| } |
| } |
| |
| bool AddMemory(WasmModule* module) { |
| if (module->has_memory) { |
| error("At most one memory is supported"); |
| return false; |
| } else { |
| module->has_memory = true; |
| return true; |
| } |
| } |
| |
| // Decodes a single global entry inside a module starting at {pc_}. |
| void DecodeGlobalInModule(WasmModule* module, uint32_t index, |
| WasmGlobal* global) { |
| global->type = consume_value_type(); |
| global->mutability = consume_mutability(); |
| const byte* pos = pc(); |
| global->init = consume_init_expr(module, kWasmStmt); |
| if (global->init.kind == WasmInitExpr::kGlobalIndex) { |
| uint32_t other_index = global->init.val.global_index; |
| if (other_index >= index) { |
| errorf(pos, |
| "invalid global index in init expression, " |
| "index %u, other_index %u", |
| index, other_index); |
| } else if (module->globals[other_index].type != global->type) { |
| errorf(pos, |
| "type mismatch in global initialization " |
| "(from global #%u), expected %s, got %s", |
| other_index, ValueTypes::TypeName(global->type), |
| ValueTypes::TypeName(module->globals[other_index].type)); |
| } |
| } else { |
| if (!ValueTypes::IsSubType(TypeOf(module, global->init), global->type)) { |
| errorf(pos, "type error in global initialization, expected %s, got %s", |
| ValueTypes::TypeName(global->type), |
| ValueTypes::TypeName(TypeOf(module, global->init))); |
| } |
| } |
| } |
| |
| // Calculate individual global offsets and total size of globals table. |
| void CalculateGlobalOffsets(WasmModule* module) { |
| uint32_t untagged_offset = 0; |
| uint32_t tagged_offset = 0; |
| uint32_t num_imported_mutable_globals = 0; |
| for (WasmGlobal& global : module->globals) { |
| if (global.mutability && global.imported) { |
| global.index = num_imported_mutable_globals++; |
| } else if (ValueTypes::IsReferenceType(global.type)) { |
| global.offset = tagged_offset; |
| // All entries in the tagged_globals_buffer have size 1. |
| tagged_offset++; |
| } else { |
| byte size = |
| ValueTypes::MemSize(ValueTypes::MachineTypeFor(global.type)); |
| untagged_offset = (untagged_offset + size - 1) & ~(size - 1); // align |
| global.offset = untagged_offset; |
| untagged_offset += size; |
| } |
| } |
| module->untagged_globals_buffer_size = untagged_offset; |
| module->tagged_globals_buffer_size = tagged_offset; |
| } |
| |
| // Verifies the body (code) of a given function. |
| void VerifyFunctionBody(AccountingAllocator* allocator, uint32_t func_num, |
| const ModuleWireBytes& wire_bytes, |
| const WasmModule* module, WasmFunction* function) { |
| WasmFunctionName func_name(function, |
| wire_bytes.GetNameOrNull(function, module)); |
| if (FLAG_trace_wasm_decoder) { |
| StdoutStream{} << "Verifying wasm function " << func_name << std::endl; |
| } |
| FunctionBody body = { |
| function->sig, function->code.offset(), |
| start_ + GetBufferRelativeOffset(function->code.offset()), |
| start_ + GetBufferRelativeOffset(function->code.end_offset())}; |
| |
| DecodeResult result; |
| { |
| auto time_counter = SELECT_WASM_COUNTER(GetCounters(), origin_, |
| wasm_decode, function_time); |
| |
| TimedHistogramScope wasm_decode_function_time_scope(time_counter); |
| WasmFeatures unused_detected_features; |
| result = VerifyWasmCode(allocator, enabled_features_, module, |
| &unused_detected_features, body); |
| } |
| |
| // If the decode failed and this is the first error, set error code and |
| // location. |
| if (result.failed() && intermediate_error_.empty()) { |
| // Wrap the error message from the function decoder. |
| std::ostringstream error_msg; |
| error_msg << "in function " << func_name << ": " |
| << result.error().message(); |
| intermediate_error_ = WasmError{result.error().offset(), error_msg.str()}; |
| } |
| } |
| |
| uint32_t consume_sig_index(WasmModule* module, FunctionSig** sig) { |
| const byte* pos = pc_; |
| uint32_t sig_index = consume_u32v("signature index"); |
| if (sig_index >= module->signatures.size()) { |
| errorf(pos, "signature index %u out of bounds (%d signatures)", sig_index, |
| static_cast<int>(module->signatures.size())); |
| *sig = nullptr; |
| return 0; |
| } |
| *sig = module->signatures[sig_index]; |
| return sig_index; |
| } |
| |
| uint32_t consume_exception_sig_index(WasmModule* module, FunctionSig** sig) { |
| const byte* pos = pc_; |
| uint32_t sig_index = consume_sig_index(module, sig); |
| if (*sig && (*sig)->return_count() != 0) { |
| errorf(pos, "exception signature %u has non-void return", sig_index); |
| *sig = nullptr; |
| return 0; |
| } |
| return sig_index; |
| } |
| |
| uint32_t consume_count(const char* name, size_t maximum) { |
| const byte* p = pc_; |
| uint32_t count = consume_u32v(name); |
| if (count > maximum) { |
| errorf(p, "%s of %u exceeds internal limit of %zu", name, count, maximum); |
| return static_cast<uint32_t>(maximum); |
| } |
| return count; |
| } |
| |
| uint32_t consume_func_index(WasmModule* module, WasmFunction** func, |
| const char* name) { |
| return consume_index(name, &module->functions, func); |
| } |
| |
| uint32_t consume_global_index(WasmModule* module, WasmGlobal** global) { |
| return consume_index("global index", &module->globals, global); |
| } |
| |
| uint32_t consume_table_index(WasmModule* module, WasmTable** table) { |
| return consume_index("table index", &module->tables, table); |
| } |
| |
| uint32_t consume_exception_index(WasmModule* module, WasmException** except) { |
| return consume_index("exception index", &module->exceptions, except); |
| } |
| |
| template <typename T> |
| uint32_t consume_index(const char* name, std::vector<T>* vector, T** ptr) { |
| const byte* pos = pc_; |
| uint32_t index = consume_u32v(name); |
| if (index >= vector->size()) { |
| errorf(pos, "%s %u out of bounds (%d entr%s)", name, index, |
| static_cast<int>(vector->size()), |
| vector->size() == 1 ? "y" : "ies"); |
| *ptr = nullptr; |
| return 0; |
| } |
| *ptr = &(*vector)[index]; |
| return index; |
| } |
| |
| uint8_t validate_table_flags(const char* name) { |
| uint8_t flags = consume_u8("resizable limits flags"); |
| const byte* pos = pc(); |
| if (flags & 0xFE) { |
| errorf(pos - 1, "invalid %s limits flags", name); |
| } |
| return flags; |
| } |
| |
| uint8_t validate_memory_flags(bool* has_shared_memory) { |
| uint8_t flags = consume_u8("resizable limits flags"); |
| const byte* pos = pc(); |
| *has_shared_memory = false; |
| if (enabled_features_.threads) { |
| if (flags & 0xFC) { |
| errorf(pos - 1, "invalid memory limits flags"); |
| } else if (flags == 3) { |
| DCHECK_NOT_NULL(has_shared_memory); |
| *has_shared_memory = true; |
| } else if (flags == 2) { |
| errorf(pos - 1, |
| "memory limits flags should have maximum defined if shared is " |
| "true"); |
| } |
| } else { |
| if (flags & 0xFE) { |
| errorf(pos - 1, "invalid memory limits flags"); |
| } |
| } |
| return flags; |
| } |
| |
| void consume_resizable_limits(const char* name, const char* units, |
| uint32_t max_initial, uint32_t* initial, |
| bool* has_max, uint32_t max_maximum, |
| uint32_t* maximum, uint8_t flags) { |
| const byte* pos = pc(); |
| *initial = consume_u32v("initial size"); |
| *has_max = false; |
| if (*initial > max_initial) { |
| errorf(pos, |
| "initial %s size (%u %s) is larger than implementation limit (%u)", |
| name, *initial, units, max_initial); |
| } |
| if (flags & 1) { |
| *has_max = true; |
| pos = pc(); |
| *maximum = consume_u32v("maximum size"); |
| if (*maximum > max_maximum) { |
| errorf( |
| pos, |
| "maximum %s size (%u %s) is larger than implementation limit (%u)", |
| name, *maximum, units, max_maximum); |
| } |
| if (*maximum < *initial) { |
| errorf(pos, "maximum %s size (%u %s) is less than initial (%u %s)", |
| name, *maximum, units, *initial, units); |
| } |
| } else { |
| *has_max = false; |
| *maximum = max_initial; |
| } |
| } |
| |
| bool expect_u8(const char* name, uint8_t expected) { |
| const byte* pos = pc(); |
| uint8_t value = consume_u8(name); |
| if (value != expected) { |
| errorf(pos, "expected %s 0x%02x, got 0x%02x", name, expected, value); |
| return false; |
| } |
| return true; |
| } |
| |
| WasmInitExpr consume_init_expr(WasmModule* module, ValueType expected) { |
| const byte* pos = pc(); |
| uint8_t opcode = consume_u8("opcode"); |
| WasmInitExpr expr; |
| uint32_t len = 0; |
| switch (opcode) { |
| case kExprGetGlobal: { |
| GlobalIndexImmediate<Decoder::kValidate> imm(this, pc() - 1); |
| if (module->globals.size() <= imm.index) { |
| error("global index is out of bounds"); |
| expr.kind = WasmInitExpr::kNone; |
| expr.val.i32_const = 0; |
| break; |
| } |
| WasmGlobal* global = &module->globals[imm.index]; |
| if (global->mutability || !global->imported) { |
| error( |
| "only immutable imported globals can be used in initializer " |
| "expressions"); |
| expr.kind = WasmInitExpr::kNone; |
| expr.val.i32_const = 0; |
| break; |
| } |
| expr.kind = WasmInitExpr::kGlobalIndex; |
| expr.val.global_index = imm.index; |
| len = imm.length; |
| break; |
| } |
| case kExprI32Const: { |
| ImmI32Immediate<Decoder::kValidate> imm(this, pc() - 1); |
| expr.kind = WasmInitExpr::kI32Const; |
| expr.val.i32_const = imm.value; |
| len = imm.length; |
| break; |
| } |
| case kExprF32Const: { |
| ImmF32Immediate<Decoder::kValidate> imm(this, pc() - 1); |
| expr.kind = WasmInitExpr::kF32Const; |
| expr.val.f32_const = imm.value; |
| len = imm.length; |
| break; |
| } |
| case kExprI64Const: { |
| ImmI64Immediate<Decoder::kValidate> imm(this, pc() - 1); |
| expr.kind = WasmInitExpr::kI64Const; |
| expr.val.i64_const = imm.value; |
| len = imm.length; |
| break; |
| } |
| case kExprF64Const: { |
| ImmF64Immediate<Decoder::kValidate> imm(this, pc() - 1); |
| expr.kind = WasmInitExpr::kF64Const; |
| expr.val.f64_const = imm.value; |
| len = imm.length; |
| break; |
| } |
| case kExprRefNull: { |
| if (enabled_features_.anyref || enabled_features_.eh) { |
| expr.kind = WasmInitExpr::kRefNullConst; |
| len = 0; |
| break; |
| } |
| V8_FALLTHROUGH; |
| } |
| case kExprRefFunc: { |
| if (enabled_features_.anyref) { |
| FunctionIndexImmediate<Decoder::kValidate> imm(this, pc() - 1); |
| expr.kind = WasmInitExpr::kRefFuncConst; |
| expr.val.function_index = imm.index; |
| len = imm.length; |
| break; |
| } |
| V8_FALLTHROUGH; |
| } |
| default: { |
| error("invalid opcode in initialization expression"); |
| expr.kind = WasmInitExpr::kNone; |
| expr.val.i32_const = 0; |
| } |
| } |
| consume_bytes(len, "init code"); |
| if (!expect_u8("end opcode", kExprEnd)) { |
| expr.kind = WasmInitExpr::kNone; |
| } |
| if (expected != kWasmStmt && TypeOf(module, expr) != kWasmI32) { |
| errorf(pos, "type error in init expression, expected %s, got %s", |
| ValueTypes::TypeName(expected), |
| ValueTypes::TypeName(TypeOf(module, expr))); |
| } |
| return expr; |
| } |
| |
| // Read a mutability flag |
| bool consume_mutability() { |
| byte val = consume_u8("mutability"); |
| if (val > 1) error(pc_ - 1, "invalid mutability"); |
| return val != 0; |
| } |
| |
| // Reads a single 8-bit integer, interpreting it as a local type. |
| ValueType consume_value_type() { |
| byte val = consume_u8("value type"); |
| ValueTypeCode t = static_cast<ValueTypeCode>(val); |
| switch (t) { |
| case kLocalI32: |
| return kWasmI32; |
| case kLocalI64: |
| return kWasmI64; |
| case kLocalF32: |
| return kWasmF32; |
| case kLocalF64: |
| return kWasmF64; |
| default: |
| if (origin_ == kWasmOrigin) { |
| switch (t) { |
| case kLocalS128: |
| if (enabled_features_.simd) return kWasmS128; |
| break; |
| case kLocalFuncRef: |
| if (enabled_features_.anyref) return kWasmFuncRef; |
| break; |
| case kLocalAnyRef: |
| if (enabled_features_.anyref) return kWasmAnyRef; |
| break; |
| case kLocalExnRef: |
| if (enabled_features_.eh) return kWasmExnRef; |
| break; |
| default: |
| break; |
| } |
| } |
| error(pc_ - 1, "invalid local type"); |
| return kWasmStmt; |
| } |
| } |
| |
| // Reads a single 8-bit integer, interpreting it as a reference type. |
| ValueType consume_reference_type() { |
| byte val = consume_u8("reference type"); |
| ValueTypeCode t = static_cast<ValueTypeCode>(val); |
| switch (t) { |
| case kLocalFuncRef: |
| return kWasmFuncRef; |
| case kLocalAnyRef: |
| if (!enabled_features_.anyref) { |
| error(pc_ - 1, |
| "Invalid type. Set --experimental-wasm-anyref to use 'AnyRef'"); |
| } |
| return kWasmAnyRef; |
| default: |
| break; |
| } |
| error(pc_ - 1, "invalid reference type"); |
| return kWasmStmt; |
| } |
| |
| FunctionSig* consume_sig(Zone* zone) { |
| if (!expect_u8("type form", kWasmFunctionTypeCode)) return nullptr; |
| // parse parameter types |
| uint32_t param_count = |
| consume_count("param count", kV8MaxWasmFunctionParams); |
| if (failed()) return nullptr; |
| std::vector<ValueType> params; |
| for (uint32_t i = 0; ok() && i < param_count; ++i) { |
| ValueType param = consume_value_type(); |
| params.push_back(param); |
| } |
| std::vector<ValueType> returns; |
| // parse return types |
| const size_t max_return_count = enabled_features_.mv |
| ? kV8MaxWasmFunctionMultiReturns |
| : kV8MaxWasmFunctionReturns; |
| uint32_t return_count = consume_count("return count", max_return_count); |
| if (failed()) return nullptr; |
| for (uint32_t i = 0; ok() && i < return_count; ++i) { |
| ValueType ret = consume_value_type(); |
| returns.push_back(ret); |
| } |
| |
| if (failed()) return nullptr; |
| |
| // FunctionSig stores the return types first. |
| ValueType* buffer = zone->NewArray<ValueType>(param_count + return_count); |
| uint32_t b = 0; |
| for (uint32_t i = 0; i < return_count; ++i) buffer[b++] = returns[i]; |
| for (uint32_t i = 0; i < param_count; ++i) buffer[b++] = params[i]; |
| |
| return new (zone) FunctionSig(return_count, param_count, buffer); |
| } |
| |
| // Consume the attribute field of an exception. |
| uint32_t consume_exception_attribute() { |
| const byte* pos = pc_; |
| uint32_t attribute = consume_u32v("exception attribute"); |
| if (attribute != kExceptionAttribute) { |
| errorf(pos, "exception attribute %u not supported", attribute); |
| return 0; |
| } |
| return attribute; |
| } |
| |
| void consume_segment_header(const char* name, bool* is_active, |
| uint32_t* index, WasmInitExpr* offset) { |
| const byte* pos = pc(); |
| uint32_t flag = consume_u32v("flag"); |
| |
| // Some flag values are only valid for specific proposals. |
| if (flag == SegmentFlags::kPassive) { |
| if (!enabled_features_.bulk_memory) { |
| error( |
| "Passive element segments require --experimental-wasm-bulk-memory"); |
| return; |
| } |
| } else if (flag == SegmentFlags::kActiveWithIndex) { |
| if (!(enabled_features_.bulk_memory || enabled_features_.anyref)) { |
| error( |
| "Element segments with table indices require " |
| "--experimental-wasm-bulk-memory or --experimental-wasm-anyref"); |
| return; |
| } |
| } else if (flag != SegmentFlags::kActiveNoIndex) { |
| errorf(pos, "illegal flag value %u. Must be 0, 1, or 2", flag); |
| return; |
| } |
| |
| // We know now that the flag is valid. Time to read the rest. |
| if (flag == SegmentFlags::kActiveNoIndex) { |
| *is_active = true; |
| *index = 0; |
| *offset = consume_init_expr(module_.get(), kWasmI32); |
| return; |
| } |
| if (flag == SegmentFlags::kPassive) { |
| *is_active = false; |
| return; |
| } |
| if (flag == SegmentFlags::kActiveWithIndex) { |
| *is_active = true; |
| *index = consume_u32v(name); |
| *offset = consume_init_expr(module_.get(), kWasmI32); |
| } |
| } |
| |
| uint32_t consume_element_func_index() { |
| WasmFunction* func = nullptr; |
| uint32_t index = |
| consume_func_index(module_.get(), &func, "element function index"); |
| if (failed()) return index; |
| DCHECK_NE(func, nullptr); |
| DCHECK_EQ(index, func->func_index); |
| DCHECK_NE(index, WasmElemSegment::kNullIndex); |
| return index; |
| } |
| |
| uint32_t consume_passive_element() { |
| uint32_t index = WasmElemSegment::kNullIndex; |
| uint8_t opcode = consume_u8("element opcode"); |
| if (failed()) return index; |
| switch (opcode) { |
| case kExprRefNull: |
| index = WasmElemSegment::kNullIndex; |
| break; |
| case kExprRefFunc: |
| index = consume_element_func_index(); |
| if (failed()) return index; |
| break; |
| default: |
| error("invalid opcode in element"); |
| break; |
| } |
| expect_u8("end opcode", kExprEnd); |
| return index; |
| } |
| }; |
| |
| ModuleResult DecodeWasmModule(const WasmFeatures& enabled, |
| const byte* module_start, const byte* module_end, |
| bool verify_functions, ModuleOrigin origin, |
| Counters* counters, |
| AccountingAllocator* allocator) { |
| auto counter = |
| SELECT_WASM_COUNTER(counters, origin, wasm_decode, module_time); |
| TimedHistogramScope wasm_decode_module_time_scope(counter); |
| size_t size = module_end - module_start; |
| CHECK_LE(module_start, module_end); |
| if (size >= kV8MaxWasmModuleSize) { |
| return ModuleResult{WasmError{0, "size > maximum module size (%zu): %zu", |
| kV8MaxWasmModuleSize, size}}; |
| } |
| // TODO(bradnelson): Improve histogram handling of size_t. |
| auto size_counter = |
| SELECT_WASM_COUNTER(counters, origin, wasm, module_size_bytes); |
| size_counter->AddSample(static_cast<int>(size)); |
| // Signatures are stored in zone memory, which have the same lifetime |
| // as the {module}. |
| ModuleDecoderImpl decoder(enabled, module_start, module_end, origin); |
| ModuleResult result = |
| decoder.DecodeModule(counters, allocator, verify_functions); |
| // TODO(bradnelson): Improve histogram handling of size_t. |
| // TODO(titzer): this isn't accurate, since it doesn't count the data |
| // allocated on the C++ heap. |
| // https://bugs.chromium.org/p/chromium/issues/detail?id=657320 |
| if (result.ok()) { |
| auto peak_counter = SELECT_WASM_COUNTER(counters, origin, wasm_decode, |
| module_peak_memory_bytes); |
| peak_counter->AddSample( |
| static_cast<int>(result.value()->signature_zone->allocation_size())); |
| } |
| return result; |
| } |
| |
| ModuleDecoder::ModuleDecoder(const WasmFeatures& enabled) |
| : enabled_features_(enabled) {} |
| |
| ModuleDecoder::~ModuleDecoder() = default; |
| |
| const std::shared_ptr<WasmModule>& ModuleDecoder::shared_module() const { |
| return impl_->shared_module(); |
| } |
| |
| void ModuleDecoder::StartDecoding(Counters* counters, |
| AccountingAllocator* allocator, |
| ModuleOrigin origin) { |
| DCHECK_NULL(impl_); |
| impl_.reset(new ModuleDecoderImpl(enabled_features_, origin)); |
| impl_->StartDecoding(counters, allocator); |
| } |
| |
| void ModuleDecoder::DecodeModuleHeader(Vector<const uint8_t> bytes, |
| uint32_t offset) { |
| impl_->DecodeModuleHeader(bytes, offset); |
| } |
| |
| void ModuleDecoder::DecodeSection(SectionCode section_code, |
| Vector<const uint8_t> bytes, uint32_t offset, |
| bool verify_functions) { |
| impl_->DecodeSection(section_code, bytes, offset, verify_functions); |
| } |
| |
| void ModuleDecoder::DecodeFunctionBody(uint32_t index, uint32_t length, |
| uint32_t offset, bool verify_functions) { |
| impl_->DecodeFunctionBody(index, length, offset, verify_functions); |
| } |
| |
| bool ModuleDecoder::CheckFunctionsCount(uint32_t functions_count, |
| uint32_t offset) { |
| return impl_->CheckFunctionsCount(functions_count, offset); |
| } |
| |
| ModuleResult ModuleDecoder::FinishDecoding(bool verify_functions) { |
| return impl_->FinishDecoding(verify_functions); |
| } |
| |
| SectionCode ModuleDecoder::IdentifyUnknownSection(Decoder* decoder, |
| const byte* end) { |
| WireBytesRef string = consume_string(decoder, true, "section name"); |
| if (decoder->failed() || decoder->pc() > end) { |
| return kUnknownSectionCode; |
| } |
| const byte* section_name_start = |
| decoder->start() + decoder->GetBufferRelativeOffset(string.offset()); |
| |
| TRACE(" +%d section name : \"%.*s\"\n", |
| static_cast<int>(section_name_start - decoder->start()), |
| string.length() < 20 ? string.length() : 20, section_name_start); |
| |
| if (string.length() == num_chars(kNameString) && |
| strncmp(reinterpret_cast<const char*>(section_name_start), kNameString, |
| num_chars(kNameString)) == 0) { |
| return kNameSectionCode; |
| } else if (string.length() == num_chars(kSourceMappingURLString) && |
| strncmp(reinterpret_cast<const char*>(section_name_start), |
| kSourceMappingURLString, |
| num_chars(kSourceMappingURLString)) == 0) { |
| return kSourceMappingURLSectionCode; |
| } else if (string.length() == num_chars(kCompilationHintsString) && |
| strncmp(reinterpret_cast<const char*>(section_name_start), |
| kCompilationHintsString, |
| num_chars(kCompilationHintsString)) == 0) { |
| return kCompilationHintsSectionCode; |
| } |
| return kUnknownSectionCode; |
| } |
| |
| bool ModuleDecoder::ok() { return impl_->ok(); } |
| |
| FunctionSig* DecodeWasmSignatureForTesting(const WasmFeatures& enabled, |
| Zone* zone, const byte* start, |
| const byte* end) { |
| ModuleDecoderImpl decoder(enabled, start, end, kWasmOrigin); |
| return decoder.DecodeFunctionSignature(zone, start); |
| } |
| |
| WasmInitExpr DecodeWasmInitExprForTesting(const WasmFeatures& enabled, |
| const byte* start, const byte* end) { |
| AccountingAllocator allocator; |
| ModuleDecoderImpl decoder(enabled, start, end, kWasmOrigin); |
| return decoder.DecodeInitExpr(start); |
| } |
| |
| FunctionResult DecodeWasmFunctionForTesting( |
| const WasmFeatures& enabled, Zone* zone, const ModuleWireBytes& wire_bytes, |
| const WasmModule* module, const byte* function_start, |
| const byte* function_end, Counters* counters) { |
| size_t size = function_end - function_start; |
| CHECK_LE(function_start, function_end); |
| auto size_histogram = SELECT_WASM_COUNTER(counters, module->origin, wasm, |
| function_size_bytes); |
| // TODO(bradnelson): Improve histogram handling of ptrdiff_t. |
| size_histogram->AddSample(static_cast<int>(size)); |
| if (size > kV8MaxWasmFunctionSize) { |
| return FunctionResult{WasmError{0, |
| "size > maximum function size (%zu): %zu", |
| kV8MaxWasmFunctionSize, size}}; |
| } |
| ModuleDecoderImpl decoder(enabled, function_start, function_end, kWasmOrigin); |
| decoder.SetCounters(counters); |
| return decoder.DecodeSingleFunction(zone, wire_bytes, module, |
| base::make_unique<WasmFunction>()); |
| } |
| |
| AsmJsOffsetsResult DecodeAsmJsOffsets(const byte* tables_start, |
| const byte* tables_end) { |
| AsmJsOffsets table; |
| |
| Decoder decoder(tables_start, tables_end); |
| uint32_t functions_count = decoder.consume_u32v("functions count"); |
| // Reserve space for the entries, taking care of invalid input. |
| if (functions_count < static_cast<uint32_t>(tables_end - tables_start)) { |
| table.reserve(functions_count); |
| } |
| |
| for (uint32_t i = 0; i < functions_count && decoder.ok(); ++i) { |
| uint32_t size = decoder.consume_u32v("table size"); |
| if (size == 0) { |
| table.emplace_back(); |
| continue; |
| } |
| if (!decoder.checkAvailable(size)) { |
| decoder.error("illegal asm function offset table size"); |
| } |
| const byte* table_end = decoder.pc() + size; |
| uint32_t locals_size = decoder.consume_u32v("locals size"); |
| int function_start_position = decoder.consume_u32v("function start pos"); |
| int last_byte_offset = locals_size; |
| int last_asm_position = function_start_position; |
| std::vector<AsmJsOffsetEntry> func_asm_offsets; |
| func_asm_offsets.reserve(size / 4); // conservative estimation |
| // Add an entry for the stack check, associated with position 0. |
| func_asm_offsets.push_back( |
| {0, function_start_position, function_start_position}); |
| while (decoder.ok() && decoder.pc() < table_end) { |
| last_byte_offset += decoder.consume_u32v("byte offset delta"); |
| int call_position = |
| last_asm_position + decoder.consume_i32v("call position delta"); |
| int to_number_position = |
| call_position + decoder.consume_i32v("to_number position delta"); |
| last_asm_position = to_number_position; |
| func_asm_offsets.push_back( |
| {last_byte_offset, call_position, to_number_position}); |
| } |
| if (decoder.pc() != table_end) { |
| decoder.error("broken asm offset table"); |
| } |
| table.push_back(std::move(func_asm_offsets)); |
| } |
| if (decoder.more()) decoder.error("unexpected additional bytes"); |
| |
| return decoder.toResult(std::move(table)); |
| } |
| |
| std::vector<CustomSectionOffset> DecodeCustomSections(const byte* start, |
| const byte* end) { |
| Decoder decoder(start, end); |
| decoder.consume_bytes(4, "wasm magic"); |
| decoder.consume_bytes(4, "wasm version"); |
| |
| std::vector<CustomSectionOffset> result; |
| |
| while (decoder.more()) { |
| byte section_code = decoder.consume_u8("section code"); |
| uint32_t section_length = decoder.consume_u32v("section length"); |
| uint32_t section_start = decoder.pc_offset(); |
| if (section_code != 0) { |
| // Skip known sections. |
| decoder.consume_bytes(section_length, "section bytes"); |
| continue; |
| } |
| uint32_t name_length = decoder.consume_u32v("name length"); |
| uint32_t name_offset = decoder.pc_offset(); |
| decoder.consume_bytes(name_length, "section name"); |
| uint32_t payload_offset = decoder.pc_offset(); |
| if (section_length < (payload_offset - section_start)) { |
| decoder.error("invalid section length"); |
| break; |
| } |
| uint32_t payload_length = section_length - (payload_offset - section_start); |
| decoder.consume_bytes(payload_length); |
| if (decoder.failed()) break; |
| result.push_back({{section_start, section_length}, |
| {name_offset, name_length}, |
| {payload_offset, payload_length}}); |
| } |
| |
| return result; |
| } |
| |
| namespace { |
| |
| bool FindNameSection(Decoder* decoder) { |
| static constexpr int kModuleHeaderSize = 8; |
| decoder->consume_bytes(kModuleHeaderSize, "module header"); |
| |
| WasmSectionIterator section_iter(decoder); |
| |
| while (decoder->ok() && section_iter.more() && |
| section_iter.section_code() != kNameSectionCode) { |
| section_iter.advance(true); |
| } |
| if (!section_iter.more()) return false; |
| |
| // Reset the decoder to not read beyond the name section end. |
| decoder->Reset(section_iter.payload(), decoder->pc_offset()); |
| return true; |
| } |
| |
| } // namespace |
| |
| void DecodeFunctionNames(const byte* module_start, const byte* module_end, |
| std::unordered_map<uint32_t, WireBytesRef>* names) { |
| DCHECK_NOT_NULL(names); |
| DCHECK(names->empty()); |
| |
| Decoder decoder(module_start, module_end); |
| if (!FindNameSection(&decoder)) return; |
| |
| while (decoder.ok() && decoder.more()) { |
| uint8_t name_type = decoder.consume_u8("name type"); |
| if (name_type & 0x80) break; // no varuint7 |
| |
| uint32_t name_payload_len = decoder.consume_u32v("name payload length"); |
| if (!decoder.checkAvailable(name_payload_len)) break; |
| |
| if (name_type != NameSectionKindCode::kFunction) { |
| decoder.consume_bytes(name_payload_len, "name subsection payload"); |
| continue; |
| } |
| uint32_t functions_count = decoder.consume_u32v("functions count"); |
| |
| for (; decoder.ok() && functions_count > 0; --functions_count) { |
| uint32_t function_index = decoder.consume_u32v("function index"); |
| WireBytesRef name = consume_string(&decoder, false, "function name"); |
| |
| // Be lenient with errors in the name section: Ignore non-UTF8 names. You |
| // can even assign to the same function multiple times (last valid one |
| // wins). |
| if (decoder.ok() && validate_utf8(&decoder, name)) { |
| names->insert(std::make_pair(function_index, name)); |
| } |
| } |
| } |
| } |
| |
| void DecodeLocalNames(const byte* module_start, const byte* module_end, |
| LocalNames* result) { |
| DCHECK_NOT_NULL(result); |
| DCHECK(result->names.empty()); |
| |
| Decoder decoder(module_start, module_end); |
| if (!FindNameSection(&decoder)) return; |
| |
| while (decoder.ok() && decoder.more()) { |
| uint8_t name_type = decoder.consume_u8("name type"); |
| if (name_type & 0x80) break; // no varuint7 |
| |
| uint32_t name_payload_len = decoder.consume_u32v("name payload length"); |
| if (!decoder.checkAvailable(name_payload_len)) break; |
| |
| if (name_type != NameSectionKindCode::kLocal) { |
| decoder.consume_bytes(name_payload_len, "name subsection payload"); |
| continue; |
| } |
| |
| uint32_t local_names_count = decoder.consume_u32v("local names count"); |
| for (uint32_t i = 0; i < local_names_count; ++i) { |
| uint32_t func_index = decoder.consume_u32v("function index"); |
| if (func_index > kMaxInt) continue; |
| result->names.emplace_back(static_cast<int>(func_index)); |
| LocalNamesPerFunction& func_names = result->names.back(); |
| result->max_function_index = |
| std::max(result->max_function_index, func_names.function_index); |
| uint32_t num_names = decoder.consume_u32v("namings count"); |
| for (uint32_t k = 0; k < num_names; ++k) { |
| uint32_t local_index = decoder.consume_u32v("local index"); |
| WireBytesRef name = consume_string(&decoder, true, "local name"); |
| if (!decoder.ok()) break; |
| if (local_index > kMaxInt) continue; |
| func_names.max_local_index = |
| std::max(func_names.max_local_index, static_cast<int>(local_index)); |
| func_names.names.emplace_back(static_cast<int>(local_index), name); |
| } |
| } |
| } |
| } |
| |
| #undef TRACE |
| |
| } // namespace wasm |
| } // namespace internal |
| } // namespace v8 |