| // Copyright 2013 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "gin/v8_initializer.h" |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <cstdint> |
| #include <memory> |
| #include <optional> |
| #include <string> |
| #include <string_view> |
| #include <utility> |
| #include <vector> |
| |
| #include "base/bits.h" |
| #include "base/check.h" |
| #include "base/check_op.h" |
| #include "base/containers/span.h" |
| #include "base/debug/alias.h" |
| #include "base/debug/crash_logging.h" |
| #include "base/feature_list.h" |
| #include "base/files/file.h" |
| #include "base/files/file_path.h" |
| #include "base/files/memory_mapped_file.h" |
| #include "base/lazy_instance.h" |
| #include "base/metrics/histogram_functions.h" |
| #include "base/metrics/histogram_macros.h" |
| #include "base/notreached.h" |
| #include "base/path_service.h" |
| #include "base/rand_util.h" |
| #include "base/strings/string_split.h" |
| #include "base/strings/string_util.h" |
| #include "base/system/sys_info.h" |
| #include "base/threading/platform_thread.h" |
| #include "base/time/time.h" |
| #include "build/build_config.h" |
| #include "gin/array_buffer.h" |
| #include "gin/gin_features.h" |
| #include "partition_alloc/page_allocator.h" |
| #include "partition_alloc/partition_address_space.h" |
| #include "tools/v8_context_snapshot/buildflags.h" |
| #include "v8/include/v8-initialization.h" |
| #include "v8/include/v8-snapshot.h" |
| |
| #if defined(V8_USE_EXTERNAL_STARTUP_DATA) |
| #if BUILDFLAG(IS_ANDROID) |
| #include "base/android/apk_assets.h" |
| #elif BUILDFLAG(IS_MAC) |
| #include "base/apple/foundation_util.h" |
| #endif |
| #endif // V8_USE_EXTERNAL_STARTUP_DATA |
| |
| namespace gin { |
| |
| namespace { |
| |
| // This global is never freed nor closed. |
| base::MemoryMappedFile* g_mapped_snapshot = nullptr; |
| |
| #if defined(V8_USE_EXTERNAL_STARTUP_DATA) |
| std::optional<gin::V8SnapshotFileType> g_snapshot_file_type; |
| #endif |
| |
| bool GenerateEntropy(unsigned char* buffer, size_t amount) { |
| base::RandBytes( |
| // SAFETY: This depends on v8 providing a valid pointer/size pair. |
| // |
| // TODO(crbug.com/338574383): The signature is fixed as it's a callback |
| // from v8, but maybe v8 can use a span. |
| UNSAFE_BUFFERS(base::span(buffer, amount))); |
| return true; |
| } |
| |
| void GetMappedFileData(base::MemoryMappedFile* mapped_file, |
| v8::StartupData* data) { |
| if (mapped_file) { |
| data->data = reinterpret_cast<const char*>(mapped_file->data()); |
| data->raw_size = static_cast<int>(mapped_file->length()); |
| } else { |
| data->data = nullptr; |
| data->raw_size = 0; |
| } |
| } |
| |
| #if defined(V8_USE_EXTERNAL_STARTUP_DATA) |
| |
| #if BUILDFLAG(IS_ANDROID) |
| const char kV8ContextSnapshotFileName64[] = "v8_context_snapshot_64.bin"; |
| const char kV8ContextSnapshotFileName32[] = "v8_context_snapshot_32.bin"; |
| const char kSnapshotFileName64[] = "snapshot_blob_64.bin"; |
| const char kSnapshotFileName32[] = "snapshot_blob_32.bin"; |
| |
| #if defined(__LP64__) |
| #define kV8ContextSnapshotFileName kV8ContextSnapshotFileName64 |
| #define kSnapshotFileName kSnapshotFileName64 |
| #else |
| #define kV8ContextSnapshotFileName kV8ContextSnapshotFileName32 |
| #define kSnapshotFileName kSnapshotFileName32 |
| #endif |
| |
| #else // BUILDFLAG(IS_ANDROID) |
| #if BUILDFLAG(USE_V8_CONTEXT_SNAPSHOT) |
| const char kV8ContextSnapshotFileName[] = |
| BUILDFLAG(V8_CONTEXT_SNAPSHOT_FILENAME); |
| #endif |
| const char kSnapshotFileName[] = "snapshot_blob.bin"; |
| #endif // BUILDFLAG(IS_ANDROID) |
| |
| const char* GetSnapshotFileName(const V8SnapshotFileType file_type) { |
| switch (file_type) { |
| case V8SnapshotFileType::kDefault: |
| return kSnapshotFileName; |
| case V8SnapshotFileType::kWithAdditionalContext: |
| #if BUILDFLAG(USE_V8_CONTEXT_SNAPSHOT) |
| return kV8ContextSnapshotFileName; |
| #else |
| NOTREACHED_IN_MIGRATION(); |
| return nullptr; |
| #endif |
| } |
| NOTREACHED_IN_MIGRATION(); |
| return nullptr; |
| } |
| |
| void GetV8FilePath(const char* file_name, base::FilePath* path_out) { |
| #if BUILDFLAG(IS_ANDROID) |
| // This is the path within the .apk. |
| *path_out = |
| base::FilePath(FILE_PATH_LITERAL("assets")).AppendASCII(file_name); |
| #elif BUILDFLAG(IS_MAC) |
| *path_out = base::apple::PathForFrameworkBundleResource(file_name); |
| #else |
| base::FilePath data_path; |
| bool r = base::PathService::Get(base::DIR_ASSETS, &data_path); |
| DCHECK(r); |
| *path_out = data_path.AppendASCII(file_name); |
| #endif |
| } |
| |
| bool MapV8File(base::File file, |
| base::MemoryMappedFile::Region region, |
| base::MemoryMappedFile** mmapped_file_out) { |
| DCHECK(*mmapped_file_out == NULL); |
| std::unique_ptr<base::MemoryMappedFile> mmapped_file( |
| new base::MemoryMappedFile()); |
| if (mmapped_file->Initialize(std::move(file), region)) { |
| *mmapped_file_out = mmapped_file.release(); |
| return true; |
| } |
| return false; |
| } |
| |
| base::File OpenV8File(const char* file_name, |
| base::MemoryMappedFile::Region* region_out) { |
| // Re-try logic here is motivated by http://crbug.com/479537 |
| // for A/V on Windows (https://support.microsoft.com/en-us/kb/316609). |
| |
| base::FilePath path; |
| GetV8FilePath(file_name, &path); |
| |
| #if BUILDFLAG(IS_ANDROID) |
| base::File file(base::android::OpenApkAsset(path.value(), region_out)); |
| #else |
| // Re-try logic here is motivated by http://crbug.com/479537 |
| // for A/V on Windows (https://support.microsoft.com/en-us/kb/316609). |
| const int kMaxOpenAttempts = 5; |
| const int kOpenRetryDelayMillis = 250; |
| |
| int flags = base::File::FLAG_OPEN | base::File::FLAG_READ; |
| base::File file; |
| for (int attempt = 0; attempt < kMaxOpenAttempts; attempt++) { |
| file.Initialize(path, flags); |
| if (file.IsValid()) { |
| *region_out = base::MemoryMappedFile::Region::kWholeFile; |
| break; |
| } else if (file.error_details() != base::File::FILE_ERROR_IN_USE) { |
| break; |
| } else if (kMaxOpenAttempts - 1 != attempt) { |
| base::PlatformThread::Sleep(base::Milliseconds(kOpenRetryDelayMillis)); |
| } |
| } |
| #endif // BUILDFLAG(IS_ANDROID) |
| return file; |
| } |
| |
| #endif // defined(V8_USE_EXTERNAL_STARTUP_DATA) |
| |
| template <int LENGTH> |
| void SetV8Flags(const char (&flag)[LENGTH]) { |
| v8::V8::SetFlagsFromString(flag, LENGTH - 1); |
| } |
| |
| void SetV8FlagsFormatted(const char* format, ...) { |
| char buffer[128]; |
| va_list args; |
| va_start(args, format); |
| int length = base::vsnprintf(buffer, sizeof(buffer), format, args); |
| if (length <= 0 || sizeof(buffer) <= static_cast<unsigned>(length)) { |
| PLOG(ERROR) << "Invalid formatted V8 flag: " << format; |
| return; |
| } |
| v8::V8::SetFlagsFromString(buffer, length); |
| } |
| |
| template <size_t N, size_t M> |
| void SetV8FlagsIfOverridden(const base::Feature& feature, |
| const char (&enabling_flag)[N], |
| const char (&disabling_flag)[M]) { |
| auto overridden_state = base::FeatureList::GetStateIfOverridden(feature); |
| if (!overridden_state.has_value()) { |
| return; |
| } |
| if (overridden_state.value()) { |
| SetV8Flags(enabling_flag); |
| } else { |
| SetV8Flags(disabling_flag); |
| } |
| } |
| |
| void SetFlags(IsolateHolder::ScriptMode mode, |
| const std::string js_command_line_flags) { |
| // We assume that all feature flag defaults correspond to the default |
| // values of the corresponding V8 flags. |
| SetV8FlagsIfOverridden(features::kV8CompactCodeSpaceWithStack, |
| "--compact-code-space-with-stack", |
| "--no-compact-code-space-with-stack"); |
| SetV8FlagsIfOverridden(features::kV8CompactWithStack, "--compact-with-stack", |
| "--no-compact-with-stack"); |
| SetV8FlagsIfOverridden(features::kV8OptimizeJavascript, "--opt", "--no-opt"); |
| SetV8FlagsIfOverridden(features::kV8FlushBytecode, "--flush-bytecode", |
| "--no-flush-bytecode"); |
| SetV8FlagsIfOverridden(features::kV8FlushBaselineCode, |
| "--flush-baseline-code", "--no-flush-baseline-code"); |
| SetV8FlagsIfOverridden(features::kV8FlushCodeBasedOnTabVisibility, |
| "--flush-code-based-on-tab-visibility", |
| "--no-flush-code-based-on-tab-visibility"); |
| SetV8FlagsIfOverridden(features::kV8FlushCodeBasedOnTime, |
| "--flush-code-based-on-time", |
| "--no-flush-code-based-on-time"); |
| SetV8FlagsIfOverridden(features::kV8OffThreadFinalization, |
| "--finalize-streaming-on-background", |
| "--no-finalize-streaming-on-background"); |
| if (base::FeatureList::IsEnabled(features::kV8DelayMemoryReducer)) { |
| SetV8FlagsFormatted( |
| "--gc-memory-reducer-start-delay-ms=%i", |
| static_cast<int>( |
| features::kV8MemoryReducerStartDelay.Get().InMilliseconds())); |
| } |
| SetV8FlagsIfOverridden(features::kV8ConcurrentMarkingHighPriorityThreads, |
| "--concurrent-marking-high-priority-threads", |
| "--no-concurrent-marking-high-priority-threads"); |
| SetV8FlagsIfOverridden(features::kV8LazyFeedbackAllocation, |
| "--lazy-feedback-allocation", |
| "--no-lazy-feedback-allocation"); |
| SetV8FlagsIfOverridden(features::kV8PerContextMarkingWorklist, |
| "--stress-per-context-marking-worklist", |
| "--no-stress-per-context-marking-worklist"); |
| SetV8FlagsIfOverridden(features::kV8FlushEmbeddedBlobICache, |
| "--experimental-flush-embedded-blob-icache", |
| "--no-experimental-flush-embedded-blob-icache"); |
| SetV8FlagsIfOverridden(features::kV8ReduceConcurrentMarkingTasks, |
| "--gc-experiment-reduce-concurrent-marking-tasks", |
| "--no-gc-experiment-reduce-concurrent-marking-tasks"); |
| SetV8FlagsIfOverridden(features::kV8NoReclaimUnmodifiedWrappers, |
| "--no-reclaim-unmodified-wrappers", |
| "--reclaim-unmodified-wrappers"); |
| SetV8FlagsIfOverridden( |
| features::kV8ExperimentalRegexpEngine, |
| "--enable-experimental-regexp-engine-on-excessive-backtracks", |
| "--no-enable-experimental-regexp-engine-on-excessive-backtracks"); |
| SetV8FlagsIfOverridden(features::kV8TurboFastApiCalls, |
| "--turbo-fast-api-calls", "--no-turbo-fast-api-calls"); |
| SetV8FlagsIfOverridden(features::kV8MegaDomIC, "--mega-dom-ic", |
| "--no-mega-dom-ic"); |
| SetV8FlagsIfOverridden(features::kV8Maglev, "--maglev", "--no-maglev"); |
| SetV8FlagsIfOverridden(features::kV8ConcurrentMaglevHighPriorityThreads, |
| "--concurrent-maglev-high-priority-threads", |
| "--no-concurrent-maglev-high-priority-threads"); |
| if (base::FeatureList::IsEnabled(features::kV8MemoryReducer)) { |
| SetV8FlagsFormatted("--memory-reducer-gc-count=%i", |
| features::kV8MemoryReducerGCCount.Get()); |
| } |
| SetV8FlagsIfOverridden(features::kV8IdleGcOnContextDisposal, |
| "--idle-gc-on-context-disposal", |
| "--no-idle-gc-on-context-disposal"); |
| SetV8FlagsIfOverridden(features::kV8GCOptimizeSweepForMutator, |
| "--cppheap-optimize-sweep-for-mutator", |
| "--no-cppheap-optimize-sweep-for-mutator"); |
| SetV8FlagsIfOverridden(features::kV8MinorMS, "--minor-ms", "--no-minor-ms"); |
| if (base::FeatureList::IsEnabled(features::kV8ScavengerHigherCapacity)) { |
| SetV8FlagsFormatted("--scavenger-max-new-space-capacity-mb=%i", |
| features::kV8ScavengerMaxCapacity.Get()); |
| } |
| SetV8FlagsIfOverridden(features::kV8Sparkplug, "--sparkplug", |
| "--no-sparkplug"); |
| SetV8FlagsIfOverridden(features::kV8Turbofan, "--turbofan", "--no-turbofan"); |
| SetV8FlagsIfOverridden(features::kV8Turboshaft, "--turboshaft", |
| "--no-turboshaft"); |
| SetV8FlagsIfOverridden(features::kV8TurboshaftInstructionSelection, |
| "--turboshaft-instruction-selection", |
| "--no-turboshaft-instruction-selection"); |
| SetV8FlagsIfOverridden(features::kV8ConcurrentSparkplug, |
| "--concurrent-sparkplug", "--no-concurrent-sparkplug"); |
| SetV8FlagsIfOverridden(features::kV8SparkplugNeedsShortBuiltinCalls, |
| "--sparkplug-needs-short-builtins", |
| "--no-sparkplug-needs-short-builtins"); |
| SetV8FlagsIfOverridden(features::kV8BaselineBatchCompilation, |
| "--baseline-batch-compilation", |
| "--no-baseline-batch-compilation"); |
| SetV8FlagsIfOverridden(features::kV8ShortBuiltinCalls, |
| "--short-builtin-calls", "--no-short-builtin-calls"); |
| SetV8FlagsIfOverridden(features::kV8CodeMemoryWriteProtection, |
| "--write-protect-code-memory", |
| "--no-write-protect-code-memory"); |
| SetV8FlagsIfOverridden(features::kV8SlowHistograms, "--slow-histograms", |
| "--no-slow-histograms"); |
| SetV8FlagsIfOverridden(features::kV8SideStepTransitions, |
| "--clone_object_sidestep_transitions", |
| "--noclone_object_sidestep_transitions"); |
| SetV8FlagsIfOverridden(features::kV8SingleThreadedGCInBackground, |
| "--single-threaded-gc-in-background", |
| "--no-single-threaded-gc-in-background"); |
| SetV8FlagsIfOverridden(features::kV8SingleThreadedGCInBackgroundParallelPause, |
| "--parallel-pause-for-gc-in-background", |
| "--no-parallel-pause-for-gc-in-background"); |
| SetV8FlagsIfOverridden( |
| features::kV8SingleThreadedGCInBackgroundNoIncrementalMarking, |
| "--no-incremental-marking-for-gc-in-background", |
| "--incremental-marking-for-gc-in-background"); |
| SetV8FlagsIfOverridden(features::kV8DecommitPooledPages, |
| "--decommit-pooled-pages", |
| "--no-decommit-pooled-pages"); |
| |
| if (base::FeatureList::IsEnabled(features::kV8ConcurrentSparkplug)) { |
| if (int max_threads = features::kV8ConcurrentSparkplugMaxThreads.Get()) { |
| SetV8FlagsFormatted("--concurrent-sparkplug-max-threads=%i", max_threads); |
| } |
| SetV8FlagsIfOverridden(features::kV8ConcurrentSparkplugHighPriorityThreads, |
| "--concurrent-sparkplug-high-priority-threads", |
| "--no-concurrent-sparkplug-high-priority-threads"); |
| } |
| |
| if (base::FeatureList::IsEnabled(features::kV8FlushBytecode)) { |
| if (int old_age = features::kV8FlushBytecodeOldAge.Get()) { |
| SetV8FlagsFormatted("--bytecode-old-age=%i", old_age); |
| } |
| } |
| |
| if (base::FeatureList::IsEnabled(features::kV8FlushCodeBasedOnTime)) { |
| if (int old_time = features::kV8FlushCodeOldTime.Get()) { |
| SetV8FlagsFormatted("--bytecode-old-time=%i", old_time); |
| } |
| } |
| |
| if (base::FeatureList::IsEnabled(features::kV8EfficiencyModeTiering)) { |
| int delay = features::kV8EfficiencyModeTieringDelayTurbofan.Get(); |
| if (delay == 0) { |
| SetV8FlagsFormatted( |
| "--efficiency-mode-for-tiering-heuristics " |
| "--efficiency-mode-disable-turbofan"); |
| } else { |
| SetV8FlagsFormatted( |
| "--efficiency-mode-for-tiering-heuristics " |
| "--noefficiency-mode-disable-turbofan " |
| "--efficiency-mode-delay-turbofan=%i", |
| delay); |
| } |
| } else { |
| SetV8FlagsFormatted("--no-efficiency-mode-for-tiering-heuristics"); |
| } |
| |
| if (base::FeatureList::IsEnabled( |
| features::kWebAssemblyMoreAggressiveCodeCaching)) { |
| SetV8FlagsFormatted( |
| "--wasm-caching-threshold=%d --wasm-caching-hard-threshold=%d " |
| "--wasm-caching-timeout-ms=%d", |
| features::kWebAssemblyMoreAggressiveCodeCachingThreshold.Get(), |
| features::kWebAssemblyMoreAggressiveCodeCachingHardThreshold.Get(), |
| features::kWebAssemblyMoreAggressiveCodeCachingTimeoutMs.Get()); |
| } |
| |
| // Make sure aliases of kV8SlowHistograms only enable the feature to |
| // avoid contradicting settings between multiple finch experiments. |
| bool any_slow_histograms_alias = |
| base::FeatureList::IsEnabled( |
| features::kV8SlowHistogramsCodeMemoryWriteProtection) || |
| base::FeatureList::IsEnabled( |
| features::kV8SlowHistogramsIntelJCCErratumMitigation) || |
| base::FeatureList::IsEnabled(features::kV8SlowHistogramsSparkplug) || |
| base::FeatureList::IsEnabled( |
| features::kV8SlowHistogramsSparkplugAndroid) || |
| base::FeatureList::IsEnabled(features::kV8SlowHistogramsNoTurbofan); |
| if (any_slow_histograms_alias) { |
| SetV8Flags("--slow-histograms"); |
| } else { |
| SetV8FlagsIfOverridden(features::kV8SlowHistograms, "--slow-histograms", |
| "--no-slow-histograms"); |
| } |
| |
| SetV8FlagsIfOverridden(features::kV8IgnitionElideRedundantTdzChecks, |
| "--ignition-elide-redundant-tdz-checks", |
| "--no-ignition-elide-redundant-tdz-checks"); |
| |
| SetV8FlagsIfOverridden(features::kV8IntelJCCErratumMitigation, |
| "--intel-jcc-erratum-mitigation", |
| "--no-intel-jcc-erratum-mitigation"); |
| |
| SetV8FlagsIfOverridden(features::kV8UpdateLimitAfterLoading, |
| "--update-allocation-limits-after-loading", |
| "--no-update-allocation-limits-after-loading"); |
| |
| SetV8FlagsIfOverridden(features::kV8UseLibmTrigFunctions, |
| "--use-libm-trig-functions", |
| "--no-use-libm-trig-functions"); |
| |
| SetV8FlagsIfOverridden(features::kV8UseOriginalMessageForStackTrace, |
| "--use-original-message-for-stack-trace", |
| "--no-use-original-message-for-stack-trace"); |
| |
| // JavaScript language features. |
| SetV8FlagsIfOverridden(features::kJavaScriptIteratorHelpers, |
| "--harmony-iterator-helpers", |
| "--no-harmony-iterator-helpers"); |
| SetV8FlagsIfOverridden(features::kJavaScriptPromiseWithResolvers, |
| "--js-promise-withresolvers", |
| "--no-js-promise-withresolvers"); |
| SetV8FlagsIfOverridden(features::kJavaScriptRegExpModifiers, |
| "--js-regexp-modifiers", "--no-js-regexp-modifiers"); |
| SetV8FlagsIfOverridden(features::kJavaScriptImportAttributes, |
| "--harmony-import-attributes", |
| "--no-harmony-import-attributes"); |
| SetV8FlagsIfOverridden(features::kJavaScriptSetMethods, |
| "--harmony-set-methods", "--no-harmony-set-methods"); |
| SetV8FlagsIfOverridden(features::kJavaScriptRegExpDuplicateNamedGroups, |
| "--js-regexp-duplicate-named-groups", |
| "--no-js-duplicate-named-groups"); |
| SetV8FlagsIfOverridden(features::kJavaScriptPromiseTry, "--js-promise-try", |
| "--no-js-promise-try"); |
| |
| if (IsolateHolder::kStrictMode == mode) { |
| SetV8Flags("--use_strict"); |
| } |
| |
| // WebAssembly features. |
| |
| SetV8FlagsIfOverridden(features::kWebAssemblyDeopt, "--wasm-deopt", |
| "--no-wasm-deopt"); |
| SetV8FlagsIfOverridden(features::kWebAssemblyInlining, |
| "--experimental-wasm-inlining", |
| "--no-experimental-wasm-inlining"); |
| SetV8FlagsIfOverridden(features::kWebAssemblyInliningCallIndirect, |
| "--wasm-inlining-call-indirect", |
| "--no-wasm-inlining-call-indirect"); |
| SetV8FlagsIfOverridden(features::kWebAssemblyLiftoffCodeFlushing, |
| "--flush-liftoff-code", "--no-flush-liftoff-code"); |
| SetV8FlagsIfOverridden(features::kWebAssemblyGenericWrapper, |
| "--wasm-to-js-generic-wrapper", |
| "--no-wasm-to-js-generic-wrapper"); |
| SetV8FlagsIfOverridden(features::kWebAssemblyMultipleMemories, |
| "--experimental-wasm-multi-memory", |
| "--no-experimental-wasm-multi-memory"); |
| SetV8FlagsIfOverridden(features::kWebAssemblyTurboshaft, "--turboshaft-wasm", |
| "--no-turboshaft-wasm"); |
| SetV8FlagsIfOverridden(features::kWebAssemblyTurboshaftInstructionSelection, |
| "--turboshaft-wasm-instruction-selection-staged", |
| "--no-turboshaft-wasm-instruction-selection-staged"); |
| |
| if (js_command_line_flags.empty()) |
| return; |
| |
| // Allow the --js-flags switch to override existing flags: |
| std::vector<std::string_view> flag_list = |
| base::SplitStringPiece(js_command_line_flags, ",", base::TRIM_WHITESPACE, |
| base::SPLIT_WANT_NONEMPTY); |
| for (const auto& flag : flag_list) { |
| v8::V8::SetFlagsFromString(std::string(flag).c_str(), flag.size()); |
| } |
| } |
| |
| } // namespace |
| |
| // static |
| void V8Initializer::Initialize(IsolateHolder::ScriptMode mode, |
| const std::string js_command_line_flags, |
| v8::OOMErrorCallback oom_error_callback) { |
| static bool v8_is_initialized = false; |
| if (v8_is_initialized) |
| return; |
| |
| // Flags need to be set before InitializePlatform as they are used for |
| // system instrumentation initialization. |
| // See https://crbug.com/v8/11043 |
| SetFlags(mode, js_command_line_flags); |
| |
| v8::V8::InitializePlatform(V8Platform::Get()); |
| |
| // Set this as early as possible in order to ensure OOM errors are reported |
| // correctly. |
| v8::V8::SetFatalMemoryErrorCallback(oom_error_callback); |
| |
| // Set this early on as some initialization steps, such as the initialization |
| // of the virtual memory cage, already use V8's random number generator. |
| v8::V8::SetEntropySource(&GenerateEntropy); |
| |
| #if defined(V8_USE_EXTERNAL_STARTUP_DATA) |
| if (g_mapped_snapshot) { |
| v8::StartupData snapshot; |
| GetMappedFileData(g_mapped_snapshot, &snapshot); |
| v8::V8::SetSnapshotDataBlob(&snapshot); |
| } |
| #endif // V8_USE_EXTERNAL_STARTUP_DATA |
| |
| v8::V8::Initialize(); |
| |
| v8_is_initialized = true; |
| |
| #if defined(V8_ENABLE_SANDBOX) |
| // Record some sandbox statistics into UMA. |
| // The main reason for capturing these histograms here instead of having V8 |
| // do it is that there are no Isolates available yet, which are required |
| // for recording histograms in V8. |
| |
| // Record the mode of the sandbox. |
| // These values are persisted to logs. Entries should not be renumbered and |
| // numeric values should never be reused. This should match enum |
| // V8SandboxMode in tools/metrics/histograms/enums.xml. |
| enum class V8SandboxMode { |
| kSecure = 0, |
| kInsecure = 1, |
| kMaxValue = kInsecure, |
| }; |
| base::UmaHistogramEnumeration("V8.SandboxMode", |
| v8::V8::IsSandboxConfiguredSecurely() |
| ? V8SandboxMode::kSecure |
| : V8SandboxMode::kInsecure); |
| |
| // Record the size of the address space reservation backing the sandbox. |
| // The size will always be one of a handful of values, so use a sparse |
| // histogram to capture it. |
| size_t size = v8::V8::GetSandboxReservationSizeInBytes(); |
| DCHECK_GT(size, 0U); |
| size_t sizeInGB = size >> 30; |
| DCHECK_EQ(sizeInGB << 30, size); |
| base::UmaHistogramSparse("V8.SandboxReservationSizeGB", sizeInGB); |
| |
| // When the sandbox is enabled, ArrayBuffers must be allocated inside of |
| // it. To achieve that, PA's ConfigurablePool is created inside the sandbox |
| // and Blink then creates the ArrayBuffer partition in that Pool. |
| v8::VirtualAddressSpace* sandbox_address_space = |
| v8::V8::GetSandboxAddressSpace(); |
| const size_t max_pool_size = partition_alloc::internal:: |
| PartitionAddressSpace::ConfigurablePoolMaxSize(); |
| const size_t min_pool_size = partition_alloc::internal:: |
| PartitionAddressSpace::ConfigurablePoolMinSize(); |
| size_t pool_size = max_pool_size; |
| // Try to reserve the maximum size of the pool at first, then keep halving |
| // the size on failure until it succeeds. |
| uintptr_t pool_base = 0; |
| while (!pool_base && pool_size >= min_pool_size) { |
| pool_base = sandbox_address_space->AllocatePages( |
| 0, pool_size, pool_size, v8::PagePermissions::kNoAccess); |
| if (!pool_base) { |
| pool_size /= 2; |
| } |
| } |
| // The V8 sandbox is guaranteed to be large enough to host the pool. |
| CHECK(pool_base); |
| partition_alloc::internal::PartitionAddressSpace::InitConfigurablePool( |
| pool_base, pool_size); |
| // TODO(saelo) maybe record the size of the Pool into UMA. |
| #endif // V8_ENABLE_SANDBOX |
| |
| // Initialize the partition used by gin::ArrayBufferAllocator instances. This |
| // needs to happen now, after the V8 sandbox has been initialized, so that |
| // the partition is placed inside the configurable pool initialized above. |
| ArrayBufferAllocator::InitializePartition(); |
| } |
| |
| // static |
| void V8Initializer::GetV8ExternalSnapshotData(v8::StartupData* snapshot) { |
| GetMappedFileData(g_mapped_snapshot, snapshot); |
| } |
| |
| // static |
| void V8Initializer::GetV8ExternalSnapshotData(const char** snapshot_data_out, |
| int* snapshot_size_out) { |
| v8::StartupData snapshot; |
| GetV8ExternalSnapshotData(&snapshot); |
| *snapshot_data_out = snapshot.data; |
| *snapshot_size_out = snapshot.raw_size; |
| } |
| |
| #if defined(V8_USE_EXTERNAL_STARTUP_DATA) |
| |
| // static |
| void V8Initializer::LoadV8Snapshot(V8SnapshotFileType snapshot_file_type) { |
| if (g_mapped_snapshot) { |
| // TODO(crbug.com/40558459): Confirm not loading different type of snapshot |
| // files in a process. |
| return; |
| } |
| |
| base::MemoryMappedFile::Region file_region; |
| base::File file = |
| OpenV8File(GetSnapshotFileName(snapshot_file_type), &file_region); |
| LoadV8SnapshotFromFile(std::move(file), &file_region, snapshot_file_type); |
| } |
| |
| // static |
| void V8Initializer::LoadV8SnapshotFromFile( |
| base::File snapshot_file, |
| base::MemoryMappedFile::Region* snapshot_file_region, |
| V8SnapshotFileType snapshot_file_type) { |
| if (g_mapped_snapshot) |
| return; |
| |
| if (!snapshot_file.IsValid()) { |
| LOG(FATAL) << "Error loading V8 startup snapshot file"; |
| } |
| |
| g_snapshot_file_type = snapshot_file_type; |
| base::MemoryMappedFile::Region region = |
| base::MemoryMappedFile::Region::kWholeFile; |
| if (snapshot_file_region) { |
| region = *snapshot_file_region; |
| } |
| |
| if (!MapV8File(std::move(snapshot_file), region, &g_mapped_snapshot)) { |
| LOG(FATAL) << "Error mapping V8 startup snapshot file"; |
| } |
| } |
| |
| #if BUILDFLAG(IS_ANDROID) |
| // static |
| base::FilePath V8Initializer::GetSnapshotFilePath( |
| bool abi_32_bit, |
| V8SnapshotFileType snapshot_file_type) { |
| base::FilePath path; |
| const char* filename = nullptr; |
| switch (snapshot_file_type) { |
| case V8SnapshotFileType::kDefault: |
| filename = abi_32_bit ? kSnapshotFileName32 : kSnapshotFileName64; |
| break; |
| case V8SnapshotFileType::kWithAdditionalContext: |
| filename = abi_32_bit ? kV8ContextSnapshotFileName32 |
| : kV8ContextSnapshotFileName64; |
| break; |
| } |
| CHECK(filename); |
| |
| GetV8FilePath(filename, &path); |
| return path; |
| } |
| #endif // BUILDFLAG(IS_ANDROID) |
| |
| V8SnapshotFileType GetLoadedSnapshotFileType() { |
| DCHECK(g_snapshot_file_type.has_value()); |
| return *g_snapshot_file_type; |
| } |
| |
| #endif // defined(V8_USE_EXTERNAL_STARTUP_DATA) |
| |
| } // namespace gin |
