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Reland "[ptr-compr] Make on-heap JSTypedArrays smi-corrupting friendly"

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This is a reland of 6f9b2bd48a

We must load JSTypedArray::base_pointer in TurboFan as tagged value otherwise
this value may become stale pointer after GC.

Original change's description:
> [ptr-compr] Make on-heap JSTypedArrays smi-corrupting friendly
>
> On-heap typed arrays contain HeapObject value in |base_pointer| field
> and an offset in |external_pointer| field. When pointer compression is
> enabled we want to combine decompression with the offset addition.
> In order to do that we add an isolate root to the external_pointer value
> and therefore the data pointer computation can is a simple addition of
> a (potentially sign-extended) |base_pointer| loaded as Tagged_t value
> and an |external_pointer| value.
>
> Bug: v8:9706
> Change-Id: Id5c546c353c81fb25e3598921bc78165d10a9c44
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1807369
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63874}

Bug: v8:9706, chromium:1005599
Cq-Include-Trybots: luci.chromium.try:gpu-fyi-try-win10-nvidia-rel-64
Change-Id: I7bbd2a439306cdd11f2bb0dab5863498624d9740
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1813744
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63898}
This commit is contained in:
Igor Sheludko 2019-09-19 17:20:11 +02:00 committed by Commit Bot
parent 35d8b9a548
commit dc1a93b85c
21 changed files with 278 additions and 143 deletions
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9
src/builtins/base.tq
View File

@ -1329,9 +1329,6 @@ const kStrictReadOnlyProperty: constexpr MessageTemplate
const kString: constexpr PrimitiveType
generates 'PrimitiveType::kString';
const kExternalPointerForOnHeapArray: constexpr RawPtr
generates 'JSTypedArray::ExternalPointerForOnHeapArray()';
const kNameDictionaryInitialCapacity:
constexpr int32 generates 'NameDictionary::kInitialCapacity';
@ -2870,8 +2867,10 @@ extern macro IsMockArrayBufferAllocatorFlag(): bool;
extern macro IsPrototypeTypedArrayPrototype(implicit context: Context)(Map):
bool;
extern operator '.data_ptr' macro LoadJSTypedArrayBackingStore(JSTypedArray):
RawPtr;
extern operator '.data_ptr' macro LoadJSTypedArrayDataPtr(JSTypedArray): RawPtr;
extern macro SetJSTypedArrayOnHeapDataPtr(
JSTypedArray, ByteArray, uintptr): void;
extern macro SetJSTypedArrayOffHeapDataPtr(JSTypedArray, RawPtr, uintptr): void;
extern operator '.elements_kind' macro LoadMapElementsKind(Map): ElementsKind;
extern operator '.elements_kind' macro LoadElementsKind(JSTypedArray):

4
src/builtins/builtins-array-gen.cc
View File

@ -212,7 +212,7 @@ void ArrayBuiltinsAssembler::VisitAllTypedArrayElements(
list, start, end,
[&](TNode<Smi> index) {
GotoIf(IsDetachedBuffer(array_buffer), detached);
TNode<RawPtrT> data_ptr = LoadJSTypedArrayBackingStore(typed_array);
TNode<RawPtrT> data_ptr = LoadJSTypedArrayDataPtr(typed_array);
TNode<Object> value = LoadFixedTypedArrayElementAsTagged(
data_ptr, index, source_elements_kind_, SMI_PARAMETERS);
k_ = index;
@ -1579,7 +1579,7 @@ TF_BUILTIN(ArrayIteratorPrototypeNext, CodeStubAssembler) {
&allocate_iterator_result);
TNode<Int32T> elements_kind = LoadMapElementsKind(array_map);
TNode<RawPtrT> data_ptr = LoadJSTypedArrayBackingStore(CAST(array));
TNode<RawPtrT> data_ptr = LoadJSTypedArrayDataPtr(CAST(array));
var_value = LoadFixedTypedArrayElementAsTagged(data_ptr, CAST(index),
elements_kind);
Goto(&allocate_entry_if_needed);

18
src/builtins/builtins-typed-array-gen.cc
View File

@ -316,8 +316,8 @@ void TypedArrayBuiltinsAssembler::SetTypedArraySource(
// Grab pointers and byte lengths we need later on.
TNode<RawPtrT> target_data_ptr = LoadJSTypedArrayBackingStore(target);
TNode<RawPtrT> source_data_ptr = LoadJSTypedArrayBackingStore(source);
TNode<RawPtrT> target_data_ptr = LoadJSTypedArrayDataPtr(target);
TNode<RawPtrT> source_data_ptr = LoadJSTypedArrayDataPtr(source);
TNode<Int32T> source_el_kind = LoadElementsKind(source);
TNode<Int32T> target_el_kind = LoadElementsKind(target);
@ -749,10 +749,9 @@ TF_BUILTIN(TypedArrayOf, TypedArrayBuiltinsAssembler) {
// GC may move backing store in ToNumber, thus load backing
// store everytime in this loop.
TNode<RawPtrT> backing_store =
LoadJSTypedArrayBackingStore(new_typed_array);
StoreElement(backing_store, kind, index, value,
INTPTR_PARAMETERS);
TNode<RawPtrT> data_ptr =
LoadJSTypedArrayDataPtr(new_typed_array);
StoreElement(data_ptr, kind, index, value, INTPTR_PARAMETERS);
},
1, IndexAdvanceMode::kPost);
});
@ -971,10 +970,9 @@ TF_BUILTIN(TypedArrayFrom, TypedArrayBuiltinsAssembler) {
// GC may move backing store in map_fn, thus load backing
// store in each iteration of this loop.
TNode<RawPtrT> backing_store =
LoadJSTypedArrayBackingStore(target_obj.value());
StoreElement(backing_store, kind, index, final_value,
SMI_PARAMETERS);
TNode<RawPtrT> data_ptr =
LoadJSTypedArrayDataPtr(target_obj.value());
StoreElement(data_ptr, kind, index, final_value, SMI_PARAMETERS);
});
},
1, IndexAdvanceMode::kPost);

24
src/builtins/typed-array-createtypedarray.tq
View File

@ -27,21 +27,16 @@ namespace typed_array_createtypedarray {
isOnHeap: constexpr bool, map: Map, buffer: JSArrayBuffer,
byteOffset: uintptr, byteLength: uintptr, length: uintptr): JSTypedArray {
let elements: ByteArray;
let externalPointer: RawPtr;
let basePointer: ByteArray | Smi;
if constexpr (isOnHeap) {
elements = AllocateByteArray(byteLength);
basePointer = elements;
externalPointer = PointerConstant(kExternalPointerForOnHeapArray);
} else {
basePointer = Convert<Smi>(0);
elements = kEmptyByteArray;
// The max byteOffset is 8 * MaxSmi on the particular platform. 32 bit
// platforms are self-limiting, because we can't allocate an array bigger
// than our 32-bit arithmetic range anyway. 64 bit platforms could
// theoretically have an offset up to 2^35 - 1.
const backingStore: RawPtr = buffer.backing_store;
externalPointer = backingStore + Convert<intptr>(byteOffset);
const backingStore: uintptr = Convert<uintptr>(buffer.backing_store);
// Assert no overflow has occurred. Only assert if the mock array buffer
// allocator is NOT used. When the mock array buffer is used, impossibly
@ -49,9 +44,7 @@ namespace typed_array_createtypedarray {
// and this assertion to fail.
assert(
IsMockArrayBufferAllocatorFlag() ||
Convert<uintptr>(externalPointer) >= Convert<uintptr>(backingStore));
elements = kEmptyByteArray;
(backingStore + byteOffset) >= backingStore);
}
// We can't just build the new object with "new JSTypedArray" here because
@ -64,8 +57,15 @@ namespace typed_array_createtypedarray {
typedArray.byte_offset = byteOffset;
typedArray.byte_length = byteLength;
typedArray.length = length;
typedArray.external_pointer = externalPointer;
typedArray.base_pointer = basePointer;
if constexpr (isOnHeap) {
SetJSTypedArrayOnHeapDataPtr(typedArray, elements, byteOffset);
} else {
SetJSTypedArrayOffHeapDataPtr(
typedArray, buffer.backing_store, byteOffset);
assert(
typedArray.data_ptr ==
(buffer.backing_store + Convert<intptr>(byteOffset)));
}
SetupTypedArrayEmbedderFields(typedArray);
return typedArray;
}

80
src/codegen/code-stub-assembler.cc
View File

@ -2242,16 +2242,60 @@ TNode<IntPtrT> CodeStubAssembler::LoadPropertyArrayLength(
return Signed(DecodeWord<PropertyArray::LengthField>(value));
}
TNode<RawPtrT> CodeStubAssembler::LoadJSTypedArrayBackingStore(
TNode<RawPtrT> CodeStubAssembler::LoadJSTypedArrayDataPtr(
TNode<JSTypedArray> typed_array) {
// Backing store = external_pointer + base_pointer.
Node* external_pointer =
LoadObjectField(typed_array, JSTypedArray::kExternalPointerOffset,
MachineType::Pointer());
TNode<Object> base_pointer =
LoadObjectField(typed_array, JSTypedArray::kBasePointerOffset);
return UncheckedCast<RawPtrT>(
IntPtrAdd(external_pointer, BitcastTaggedToWord(base_pointer)));
// Data pointer = external_pointer + static_cast<Tagged_t>(base_pointer).
TNode<RawPtrT> external_pointer = LoadObjectField<RawPtrT>(
typed_array, JSTypedArray::kExternalPointerOffset);
TNode<IntPtrT> base_pointer;
#ifdef V8_COMPRESS_POINTERS
TNode<TaggedT> compressed_base =
LoadObjectField<TaggedT>(typed_array, JSTypedArray::kBasePointerOffset);
// Sign extend TaggedT to IntPtrT according to current compression scheme
// so that the addition with |external_pointer| (which already contains
// compensated offset value) below will decompress the tagged value.
// See JSTypedArray::ExternalPointerCompensationForOnHeapArray() for details.
base_pointer = ChangeInt32ToIntPtr(compressed_base);
#else
base_pointer =
LoadObjectField<IntPtrT>(typed_array, JSTypedArray::kBasePointerOffset);
#endif
return RawPtrAdd(external_pointer, base_pointer);
}
void CodeStubAssembler::SetJSTypedArrayOffHeapDataPtr(
TNode<JSTypedArray> holder, TNode<RawPtrT> base, TNode<UintPtrT> offset) {
StoreObjectFieldNoWriteBarrier(holder, JSTypedArray::kBasePointerOffset,
SmiConstant(0));
base = RawPtrAdd(base, Signed(offset));
StoreObjectFieldNoWriteBarrier<RawPtrT>(
holder, JSTypedArray::kExternalPointerOffset, base);
}
void CodeStubAssembler::SetJSTypedArrayOnHeapDataPtr(TNode<JSTypedArray> holder,
TNode<ByteArray> base,
TNode<UintPtrT> offset) {
offset = UintPtrAdd(UintPtrConstant(ByteArray::kHeaderSize - kHeapObjectTag),
offset);
if (COMPRESS_POINTERS_BOOL) {
TNode<IntPtrT> full_base = Signed(BitcastTaggedToWord(base));
TNode<Int32T> compressed_base = TruncateIntPtrToInt32(full_base);
// TODO(v8:9706): Add a way to directly use kRootRegister value.
TNode<IntPtrT> isolate_root =
IntPtrSub(full_base, ChangeInt32ToIntPtr(compressed_base));
// Add JSTypedArray::ExternalPointerCompensationForOnHeapArray() to offset.
DCHECK_EQ(
isolate()->isolate_root(),
JSTypedArray::ExternalPointerCompensationForOnHeapArray(isolate()));
// See JSTypedArray::SetOnHeapDataPtr() for details.
offset = Unsigned(IntPtrAdd(offset, isolate_root));
}
StoreObjectField(holder, JSTypedArray::kBasePointerOffset, base);
StoreObjectFieldNoWriteBarrier<UintPtrT>(
holder, JSTypedArray::kExternalPointerOffset, offset);
}
TNode<BigInt> CodeStubAssembler::LoadFixedBigInt64ArrayElementAsTagged(
@ -2537,33 +2581,33 @@ TNode<Numeric> CodeStubAssembler::LoadFixedTypedArrayElementAsTagged(
void CodeStubAssembler::StoreJSTypedArrayElementFromTagged(
TNode<Context> context, TNode<JSTypedArray> typed_array,
TNode<Smi> index_node, TNode<Object> value, ElementsKind elements_kind) {
TNode<RawPtrT> data_pointer = LoadJSTypedArrayBackingStore(typed_array);
TNode<RawPtrT> data_ptr = LoadJSTypedArrayDataPtr(typed_array);
switch (elements_kind) {
case UINT8_ELEMENTS:
case UINT8_CLAMPED_ELEMENTS:
case INT8_ELEMENTS:
case UINT16_ELEMENTS:
case INT16_ELEMENTS:
StoreElement(data_pointer, elements_kind, index_node,
SmiToInt32(CAST(value)), SMI_PARAMETERS);
StoreElement(data_ptr, elements_kind, index_node, SmiToInt32(CAST(value)),
SMI_PARAMETERS);
break;
case UINT32_ELEMENTS:
case INT32_ELEMENTS:
StoreElement(data_pointer, elements_kind, index_node,
StoreElement(data_ptr, elements_kind, index_node,
TruncateTaggedToWord32(context, value), SMI_PARAMETERS);
break;
case FLOAT32_ELEMENTS:
StoreElement(data_pointer, elements_kind, index_node,
StoreElement(data_ptr, elements_kind, index_node,
TruncateFloat64ToFloat32(LoadHeapNumberValue(CAST(value))),
SMI_PARAMETERS);
break;
case FLOAT64_ELEMENTS:
StoreElement(data_pointer, elements_kind, index_node,
StoreElement(data_ptr, elements_kind, index_node,
LoadHeapNumberValue(CAST(value)), SMI_PARAMETERS);
break;
case BIGUINT64_ELEMENTS:
case BIGINT64_ELEMENTS:
StoreElement(data_pointer, elements_kind, index_node,
StoreElement(data_ptr, elements_kind, index_node,
UncheckedCast<BigInt>(value), SMI_PARAMETERS);
break;
default:
@ -10868,8 +10912,8 @@ void CodeStubAssembler::EmitElementStore(Node* object, Node* key, Node* value,
GotoIfNot(UintPtrLessThan(intptr_key, length), &update_value_and_bailout);
}
TNode<RawPtrT> backing_store = LoadJSTypedArrayBackingStore(CAST(object));
StoreElement(backing_store, elements_kind, intptr_key, converted_value,
TNode<RawPtrT> data_ptr = LoadJSTypedArrayDataPtr(CAST(object));
StoreElement(data_ptr, elements_kind, intptr_key, converted_value,
parameter_mode);
Goto(&done);

8
src/codegen/code-stub-assembler.h
View File

@ -3536,7 +3536,13 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
// JSTypedArray helpers
TNode<UintPtrT> LoadJSTypedArrayLength(TNode<JSTypedArray> typed_array);
TNode<RawPtrT> LoadJSTypedArrayBackingStore(TNode<JSTypedArray> typed_array);
TNode<RawPtrT> LoadJSTypedArrayDataPtr(TNode<JSTypedArray> typed_array);
void SetJSTypedArrayOnHeapDataPtr(TNode<JSTypedArray> holder,
TNode<ByteArray> base,
TNode<UintPtrT> offset);
void SetJSTypedArrayOffHeapDataPtr(TNode<JSTypedArray> holder,
TNode<RawPtrT> base,
TNode<UintPtrT> offset);
template <typename TIndex>
TNode<IntPtrT> ElementOffsetFromIndex(TNode<TIndex> index, ElementsKind kind,

12
src/codegen/machine-type.h
View File

@ -114,6 +114,10 @@ class MachineType {
constexpr bool IsCompressedPointer() const {
return representation() == MachineRepresentation::kCompressedPointer;
}
constexpr static MachineRepresentation TaggedRepresentation() {
return (kTaggedSize == 4) ? MachineRepresentation::kWord32
: MachineRepresentation::kWord64;
}
constexpr static MachineRepresentation PointerRepresentation() {
return (kSystemPointerSize == 4) ? MachineRepresentation::kWord32
: MachineRepresentation::kWord64;
@ -260,6 +264,14 @@ class MachineType {
#endif
}
constexpr static MachineType TypeRawTagged() {
#ifdef V8_COMPRESS_POINTERS
return MachineType::Int32();
#else
return MachineType::Pointer();
#endif
}
constexpr static MachineType TypeCompressedTagged() {
#ifdef V8_COMPRESS_POINTERS
return MachineType::AnyCompressed();

49
src/compiler/effect-control-linearizer.cc
View File

@ -227,6 +227,8 @@ class EffectControlLinearizer {
Node* LowerStringComparison(Callable const& callable, Node* node);
Node* IsElementsKindGreaterThan(Node* kind, ElementsKind reference_kind);
Node* BuildTypedArrayDataPointer(Node* base, Node* external);
Node* ChangeInt32ToCompressedSmi(Node* value);
Node* ChangeInt32ToSmi(Node* value);
Node* ChangeInt32ToIntPtr(Node* value);
@ -5003,6 +5005,35 @@ void EffectControlLinearizer::LowerStoreDataViewElement(Node* node) {
done.PhiAt(0));
}
// Compute the data pointer, handling the case where the {external} pointer
// is the effective data pointer (i.e. the {base} is Smi zero).
Node* EffectControlLinearizer::BuildTypedArrayDataPointer(Node* base,
Node* external) {
if (IntPtrMatcher(base).Is(0)) {
return external;
} else {
if (COMPRESS_POINTERS_BOOL) {
// TurboFan does not support loading of compressed fields without
// decompression so we add the following operations to workaround that.
// We can't load the base value as word32 because in that case the
// value will not be marked as tagged in the pointer map and will not
// survive GC.
// Compress base value back to in order to be able to decompress by
// doing an unsafe add below. Both decompression and compression
// will be removed by the decompression elimination pass.
base = __ ChangeTaggedToCompressed(base);
base = __ BitcastTaggedToWord(base);
// Sign-extend Tagged_t to IntPtr according to current compression
// scheme so that the addition with |external_pointer| (which already
// contains compensated offset value) will decompress the tagged value.
// See JSTypedArray::ExternalPointerCompensationForOnHeapArray() for
// details.
base = ChangeInt32ToIntPtr(base);
}
return __ UnsafePointerAdd(base, external);
}
}
Node* EffectControlLinearizer::LowerLoadTypedElement(Node* node) {
ExternalArrayType array_type = ExternalArrayTypeOf(node->op());
Node* buffer = node->InputAt(0);
@ -5014,17 +5045,12 @@ Node* EffectControlLinearizer::LowerLoadTypedElement(Node* node) {
// ArrayBuffer (if there's any) as long as we are still operating on it.
__ Retain(buffer);
// Compute the effective storage pointer, handling the case where the
// {external} pointer is the effective storage pointer (i.e. the {base}
// is Smi zero).
Node* storage = IntPtrMatcher(base).Is(0)
? external
: __ UnsafePointerAdd(base, external);
Node* data_ptr = BuildTypedArrayDataPointer(base, external);
// Perform the actual typed element access.
return __ LoadElement(AccessBuilder::ForTypedArrayElement(
array_type, true, LoadSensitivity::kCritical),
storage, index);
data_ptr, index);
}
void EffectControlLinearizer::LowerStoreTypedElement(Node* node) {
@ -5039,16 +5065,11 @@ void EffectControlLinearizer::LowerStoreTypedElement(Node* node) {
// ArrayBuffer (if there's any) as long as we are still operating on it.
__ Retain(buffer);
// Compute the effective storage pointer, handling the case where the
// {external} pointer is the effective storage pointer (i.e. the {base}
// is Smi zero).
Node* storage = IntPtrMatcher(base).Is(0)
? external
: __ UnsafePointerAdd(base, external);
Node* data_ptr = BuildTypedArrayDataPointer(base, external);
// Perform the actual typed element access.
__ StoreElement(AccessBuilder::ForTypedArrayElement(array_type, true),
storage, index, value);
data_ptr, index, value);
}
void EffectControlLinearizer::TransitionElementsTo(Node* node, Node* array,

2
src/compiler/heap-refs.h
View File

@ -827,7 +827,7 @@ class JSTypedArrayRef : public JSObjectRef {
bool is_on_heap() const;
size_t length() const;
void* external_pointer() const;
void* data_ptr() const;
void Serialize();
bool serialized() const;

12
src/compiler/js-heap-broker.cc
View File

@ -420,7 +420,7 @@ class JSTypedArrayData : public JSObjectData {
bool is_on_heap() const { return is_on_heap_; }
size_t length() const { return length_; }
void* external_pointer() const { return external_pointer_; }
void* data_ptr() const { return data_ptr_; }
void Serialize(JSHeapBroker* broker);
bool serialized() const { return serialized_; }
@ -430,7 +430,7 @@ class JSTypedArrayData : public JSObjectData {
private:
bool const is_on_heap_;
size_t const length_;
void* const external_pointer_;
void* const data_ptr_;
bool serialized_ = false;
HeapObjectData* buffer_ = nullptr;
@ -441,7 +441,7 @@ JSTypedArrayData::JSTypedArrayData(JSHeapBroker* broker, ObjectData** storage,
: JSObjectData(broker, storage, object),
is_on_heap_(object->is_on_heap()),
length_(object->length()),
external_pointer_(object->external_pointer()) {}
data_ptr_(object->DataPtr()) {}
void JSTypedArrayData::Serialize(JSHeapBroker* broker) {
if (serialized_) return;
@ -3383,12 +3383,12 @@ base::Optional<MapRef> MapRef::FindRootMap() const {
return base::nullopt;
}
void* JSTypedArrayRef::external_pointer() const {
void* JSTypedArrayRef::data_ptr() const {
if (broker()->mode() == JSHeapBroker::kDisabled) {
AllowHandleDereference allow_handle_dereference;
return object()->external_pointer();
return object()->DataPtr();
}
return data()->AsJSTypedArray()->external_pointer();
return data()->AsJSTypedArray()->data_ptr();
}
bool MapRef::IsInobjectSlackTrackingInProgress() const {

12
src/compiler/js-native-context-specialization.cc
View File

@ -2591,12 +2591,14 @@ JSNativeContextSpecialization::BuildElementAccess(
if (typed_array.has_value()) {
length = jsgraph()->Constant(static_cast<double>(typed_array->length()));
// Load the (known) base and external pointer for the {receiver}. The
// {external_pointer} might be invalid if the {buffer} was detached, so
// we need to make sure that any access is properly guarded.
DCHECK(!typed_array->is_on_heap());
// Load the (known) data pointer for the {receiver} and set {base_pointer}
// and {external_pointer} to the values that will allow to generate typed
// element accesses using the known data pointer.
// The data pointer might be invalid if the {buffer} was detached,
// so we need to make sure that any access is properly guarded.
base_pointer = jsgraph()->ZeroConstant();
external_pointer =
jsgraph()->PointerConstant(typed_array->external_pointer());
external_pointer = jsgraph()->PointerConstant(typed_array->data_ptr());
} else {
// Load the {receiver}s length.
length = effect = graph()->NewNode(

6
src/diagnostics/objects-printer.cc
View File

@ -1388,6 +1388,12 @@ void JSTypedArray::JSTypedArrayPrint(std::ostream& os) { // NOLINT
os << "\n - byte_offset: " << byte_offset();
os << "\n - byte_length: " << byte_length();
os << "\n - length: " << length();
os << "\n - data_ptr: " << DataPtr();
Tagged_t base_ptr = static_cast<Tagged_t>(base_pointer().ptr());
os << "\n - base_pointer: "
<< reinterpret_cast<void*>(static_cast<Address>(base_ptr));
os << "\n - external_pointer: "
<< reinterpret_cast<void*>(external_pointer());
if (!buffer().IsJSArrayBuffer()) {
os << "\n <invalid buffer>\n";
return;

4
src/heap/factory.cc
View File

@ -3250,9 +3250,7 @@ Handle<JSTypedArray> Factory::NewJSTypedArray(ExternalArrayType type,
Handle<JSTypedArray>::cast(NewJSArrayBufferView(
map, empty_byte_array(), buffer, byte_offset, byte_length));
typed_array->set_length(length);
typed_array->set_external_pointer(
reinterpret_cast<byte*>(buffer->backing_store()) + byte_offset);
typed_array->set_base_pointer(Smi::kZero);
typed_array->SetOffHeapDataPtr(buffer->backing_store(), byte_offset);
return typed_array;
}

27
src/ic/accessor-assembler.cc
View File

@ -2096,8 +2096,7 @@ void AccessorAssembler::EmitElementLoad(
if (access_mode == LoadAccessMode::kHas) {
exit_point->Return(TrueConstant());
} else {
TNode<RawPtrT> backing_store =
LoadJSTypedArrayBackingStore(CAST(object));
TNode<RawPtrT> data_ptr = LoadJSTypedArrayDataPtr(CAST(object));
Label uint8_elements(this), int8_elements(this), uint16_elements(this),
int16_elements(this), uint32_elements(this), int32_elements(this),
@ -2123,50 +2122,48 @@ void AccessorAssembler::EmitElementLoad(
BIND(&uint8_elements);
{
Comment("UINT8_ELEMENTS"); // Handles UINT8_CLAMPED_ELEMENTS too.
Node* element =
Load(MachineType::Uint8(), backing_store, intptr_index);
Node* element = Load(MachineType::Uint8(), data_ptr, intptr_index);
exit_point->Return(SmiFromInt32(element));
}
BIND(&int8_elements);
{
Comment("INT8_ELEMENTS");
Node* element =
Load(MachineType::Int8(), backing_store, intptr_index);
Node* element = Load(MachineType::Int8(), data_ptr, intptr_index);
exit_point->Return(SmiFromInt32(element));
}
BIND(&uint16_elements);
{
Comment("UINT16_ELEMENTS");
TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(1));
Node* element = Load(MachineType::Uint16(), backing_store, index);
Node* element = Load(MachineType::Uint16(), data_ptr, index);
exit_point->Return(SmiFromInt32(element));
}
BIND(&int16_elements);
{
Comment("INT16_ELEMENTS");
TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(1));
Node* element = Load(MachineType::Int16(), backing_store, index);
Node* element = Load(MachineType::Int16(), data_ptr, index);
exit_point->Return(SmiFromInt32(element));
}
BIND(&uint32_elements);
{
Comment("UINT32_ELEMENTS");
TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(2));
Node* element = Load(MachineType::Uint32(), backing_store, index);
Node* element = Load(MachineType::Uint32(), data_ptr, index);
exit_point->Return(ChangeUint32ToTagged(element));
}
BIND(&int32_elements);
{
Comment("INT32_ELEMENTS");
TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(2));
Node* element = Load(MachineType::Int32(), backing_store, index);
Node* element = Load(MachineType::Int32(), data_ptr, index);
exit_point->Return(ChangeInt32ToTagged(element));
}
BIND(&float32_elements);
{
Comment("FLOAT32_ELEMENTS");
TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(2));
Node* element = Load(MachineType::Float32(), backing_store, index);
Node* element = Load(MachineType::Float32(), data_ptr, index);
var_double_value->Bind(ChangeFloat32ToFloat64(element));
Goto(rebox_double);
}
@ -2174,7 +2171,7 @@ void AccessorAssembler::EmitElementLoad(
{
Comment("FLOAT64_ELEMENTS");
TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(3));
Node* element = Load(MachineType::Float64(), backing_store, index);
Node* element = Load(MachineType::Float64(), data_ptr, index);
var_double_value->Bind(element);
Goto(rebox_double);
}
@ -2182,15 +2179,13 @@ void AccessorAssembler::EmitElementLoad(
{
Comment("BIGINT64_ELEMENTS");
exit_point->Return(LoadFixedTypedArrayElementAsTagged(
backing_store, intptr_index, BIGINT64_ELEMENTS,
INTPTR_PARAMETERS));
data_ptr, intptr_index, BIGINT64_ELEMENTS, INTPTR_PARAMETERS));
}
BIND(&biguint64_elements);
{
Comment("BIGUINT64_ELEMENTS");
exit_point->Return(LoadFixedTypedArrayElementAsTagged(
backing_store, intptr_index, BIGUINT64_ELEMENTS,
INTPTR_PARAMETERS));
data_ptr, intptr_index, BIGUINT64_ELEMENTS, INTPTR_PARAMETERS));
}
}
}

53
src/objects/js-array-buffer-inl.h
View File

@ -114,31 +114,62 @@ void JSTypedArray::set_length(size_t value) {
WriteField<size_t>(kLengthOffset, value);
}
void* JSTypedArray::external_pointer() const {
return reinterpret_cast<void*>(ReadField<Address>(kExternalPointerOffset));
Address JSTypedArray::external_pointer() const {
return ReadField<Address>(kExternalPointerOffset);
}
void JSTypedArray::set_external_pointer(void* value) {
WriteField<Address>(kExternalPointerOffset, reinterpret_cast<Address>(value));
void JSTypedArray::set_external_pointer(Address value) {
WriteField<Address>(kExternalPointerOffset, value);
}
Address JSTypedArray::ExternalPointerCompensationForOnHeapArray(
Isolate* isolate) {
#ifdef V8_COMPRESS_POINTERS
return GetIsolateRoot(isolate);
#else
return 0;
#endif
}
void JSTypedArray::RemoveExternalPointerCompensationForSerialization() {
DCHECK(is_on_heap());
Isolate* isolate = GetIsolateForPtrCompr(*this);
set_external_pointer(external_pointer() -
ExternalPointerCompensationForOnHeapArray(isolate));
}
ACCESSORS(JSTypedArray, base_pointer, Object, kBasePointerOffset)
void* JSTypedArray::DataPtr() {
// Sign extend Tagged_t to intptr_t according to current compression scheme
// so that the addition with |external_pointer| (which already contains
// compensated offset value) will decompress the tagged value.
// See JSTypedArray::ExternalPointerCompensationForOnHeapArray() for details.
return reinterpret_cast<void*>(
base_pointer().ptr() + reinterpret_cast<intptr_t>(external_pointer()));
external_pointer() + static_cast<Address>(static_cast<intptr_t>(
static_cast<Tagged_t>(base_pointer().ptr()))));
}
void JSTypedArray::SetOffHeapDataPtr(void* base, Address offset) {
set_base_pointer(Smi::kZero, SKIP_WRITE_BARRIER);
Address address = reinterpret_cast<Address>(base) + offset;
set_external_pointer(address);
DCHECK_EQ(address, reinterpret_cast<Address>(DataPtr()));
}
void JSTypedArray::SetOnHeapDataPtr(HeapObject base, Address offset) {
set_base_pointer(base);
Isolate* isolate = GetIsolateForPtrCompr(*this);
set_external_pointer(offset +
ExternalPointerCompensationForOnHeapArray(isolate));
DCHECK_EQ(base.ptr() + offset, reinterpret_cast<Address>(DataPtr()));
}
bool JSTypedArray::is_on_heap() const {
DisallowHeapAllocation no_gc;
// Checking that buffer()->backing_store() is not nullptr is not sufficient;
// it will be nullptr when byte_length is 0 as well.
return base_pointer().ptr() == elements().ptr();
}
// static
void* JSTypedArray::ExternalPointerForOnHeapArray() {
return reinterpret_cast<void*>(ByteArray::kHeaderSize - kHeapObjectTag);
return base_pointer() == elements();
}
// static

3
src/objects/js-array-buffer.cc
View File

@ -121,8 +121,7 @@ Handle<JSArrayBuffer> JSTypedArray::GetBuffer() {
// Clear the elements of the typed array.
self->set_elements(ReadOnlyRoots(isolate).empty_byte_array());
self->set_external_pointer(array_buffer->backing_store());
self->set_base_pointer(Smi::kZero);
self->SetOffHeapDataPtr(array_buffer->backing_store(), 0);
DCHECK(!self->is_on_heap());
return array_buffer;

32
src/objects/js-array-buffer.h
View File

@ -175,12 +175,6 @@ class JSTypedArray : public JSArrayBufferView {
// [length]: length of typed array in elements.
DECL_PRIMITIVE_ACCESSORS(length, size_t)
// [external_pointer]: TODO(v8:4153)
DECL_PRIMITIVE_ACCESSORS(external_pointer, void*)
// [base_pointer]: TODO(v8:4153)
DECL_ACCESSORS(base_pointer, Object)
// ES6 9.4.5.3
V8_WARN_UNUSED_RESULT static Maybe<bool> DefineOwnProperty(
Isolate* isolate, Handle<JSTypedArray> o, Handle<Object> key,
@ -196,10 +190,26 @@ class JSTypedArray : public JSArrayBufferView {
// Use with care: returns raw pointer into heap.
inline void* DataPtr();
inline void SetOffHeapDataPtr(void* base, Address offset);
inline void SetOnHeapDataPtr(HeapObject base, Address offset);
// Whether the buffer's backing store is on-heap or off-heap.
inline bool is_on_heap() const;
static inline void* ExternalPointerForOnHeapArray();
// Note: this is a pointer compression specific optimization.
// Normally, on-heap typed arrays contain HeapObject value in |base_pointer|
// field and an offset in |external_pointer|.
// When pointer compression is enabled we want to combine decompression with
// the offset addition. In order to do that we add an isolate root to the
// |external_pointer| value and therefore the data pointer computation can
// is a simple addition of a (potentially sign-extended) |base_pointer| loaded
// as Tagged_t value and an |external_pointer| value.
// For full-pointer mode the compensation value is zero.
static inline Address ExternalPointerCompensationForOnHeapArray(
Isolate* isolate);
// Subtracts external pointer compensation from the external pointer value.
inline void RemoveExternalPointerCompensationForSerialization();
static inline MaybeHandle<JSTypedArray> Validate(Isolate* isolate,
Handle<Object> receiver,
@ -238,6 +248,14 @@ class JSTypedArray : public JSArrayBufferView {
#endif
private:
friend class Deserializer;
// [base_pointer]: TODO(v8:4153)
DECL_ACCESSORS(base_pointer, Object)
// [external_pointer]: TODO(v8:4153)
DECL_PRIMITIVE_ACCESSORS(external_pointer, Address)
OBJECT_CONSTRUCTORS(JSTypedArray, JSArrayBufferView);
};

6
src/objects/objects.h
View File

@ -607,15 +607,13 @@ class Object : public TaggedImpl<HeapObjectReferenceType::STRONG, Address> {
// For use with std::unordered_set.
struct Hasher {
size_t operator()(const Object o) const {
return std::hash<v8::internal::Address>{}(o.ptr());
return std::hash<v8::internal::Address>{}(static_cast<Tagged_t>(o.ptr()));
}
};
// For use with std::map.
struct Comparer {
bool operator()(const Object a, const Object b) const {
return a.ptr() < b.ptr();
}
bool operator()(const Object a, const Object b) const { return a < b; }
};
template <class T, typename std::enable_if<std::is_arithmetic<T>::value,

20
src/snapshot/deserializer.cc
View File

@ -291,22 +291,26 @@ HeapObject Deserializer::PostProcessNewObject(HeapObject obj,
data_view.byte_offset());
} else if (obj.IsJSTypedArray()) {
JSTypedArray typed_array = JSTypedArray::cast(obj);
// Only fixup for the off-heap case.
if (!typed_array.is_on_heap()) {
Smi store_index(
reinterpret_cast<Address>(typed_array.external_pointer()));
auto backing_store = backing_stores_[store_index.value()];
// Fixup typed array pointers.
if (typed_array.is_on_heap()) {
typed_array.SetOnHeapDataPtr(HeapObject::cast(typed_array.base_pointer()),
typed_array.external_pointer());
} else {
// Serializer writes backing store ref as a DataPtr() value.
size_t store_index = reinterpret_cast<size_t>(typed_array.DataPtr());
auto backing_store = backing_stores_[store_index];
auto start = backing_store
? reinterpret_cast<byte*>(backing_store->buffer_start())
: nullptr;
typed_array.set_external_pointer(start + typed_array.byte_offset());
typed_array.SetOffHeapDataPtr(start, typed_array.byte_offset());
}
} else if (obj.IsJSArrayBuffer()) {
JSArrayBuffer buffer = JSArrayBuffer::cast(obj);
// Only fixup for the off-heap case.
if (buffer.backing_store() != nullptr) {
Smi store_index(reinterpret_cast<Address>(buffer.backing_store()));
auto backing_store = backing_stores_[store_index.value()];
// Serializer writes backing store ref in |backing_store| field.
size_t store_index = reinterpret_cast<size_t>(buffer.backing_store());
auto backing_store = backing_stores_[store_index];
if (backing_store) {
buffer.Attach(backing_store);
} else {

38
src/snapshot/serializer.cc
View File

@ -342,7 +342,7 @@ void Serializer::ObjectSerializer::SerializePrologue(SnapshotSpace space,
serializer_->SerializeObject(map);
}
int32_t Serializer::ObjectSerializer::SerializeBackingStore(
uint32_t Serializer::ObjectSerializer::SerializeBackingStore(
void* backing_store, int32_t byte_length) {
SerializerReference reference =
serializer_->reference_map()->LookupReference(backing_store);
@ -358,13 +358,15 @@ int32_t Serializer::ObjectSerializer::SerializeBackingStore(
serializer_->reference_map()->Add(backing_store, reference);
}
return static_cast<int32_t>(reference.off_heap_backing_store_index());
return reference.off_heap_backing_store_index();
}
void Serializer::ObjectSerializer::SerializeJSTypedArray() {
JSTypedArray typed_array = JSTypedArray::cast(object_);
if (!typed_array.WasDetached()) {
if (!typed_array.is_on_heap()) {
if (typed_array.is_on_heap()) {
typed_array.RemoveExternalPointerCompensationForSerialization();
} else {
if (!typed_array.WasDetached()) {
// Explicitly serialize the backing store now.
JSArrayBuffer buffer = JSArrayBuffer::cast(typed_array.buffer());
CHECK_LE(buffer.byte_length(), Smi::kMaxValue);
@ -372,21 +374,20 @@ void Serializer::ObjectSerializer::SerializeJSTypedArray() {
int32_t byte_length = static_cast<int32_t>(buffer.byte_length());
int32_t byte_offset = static_cast<int32_t>(typed_array.byte_offset());
// We need to calculate the backing store from the external pointer
// We need to calculate the backing store from the data pointer
// because the ArrayBuffer may already have been serialized.
void* backing_store = reinterpret_cast<void*>(
reinterpret_cast<intptr_t>(typed_array.external_pointer()) -
byte_offset);
int32_t ref = SerializeBackingStore(backing_store, byte_length);
reinterpret_cast<Address>(typed_array.DataPtr()) - byte_offset);
// The external_pointer is the backing_store + typed_array->byte_offset.
// To properly share the buffer, we set the backing store ref here. On
// deserialization we re-add the byte_offset to external_pointer.
typed_array.set_external_pointer(
reinterpret_cast<void*>(Smi::FromInt(ref).ptr()));
uint32_t ref = SerializeBackingStore(backing_store, byte_length);
// To properly share the buffer, we set the backing store ref as an
// off-heap offset from nullptr. On deserialization we re-set data
// pointer to proper value.
typed_array.SetOffHeapDataPtr(nullptr, ref);
DCHECK_EQ(ref, reinterpret_cast<Address>(typed_array.DataPtr()));
} else {
typed_array.SetOffHeapDataPtr(nullptr, 0);
}
} else {
typed_array.set_external_pointer(nullptr);
}
SerializeObject();
}
@ -400,8 +401,11 @@ void Serializer::ObjectSerializer::SerializeJSArrayBuffer() {
// The embedder-allocated backing store only exists for the off-heap case.
if (backing_store != nullptr) {
int32_t ref = SerializeBackingStore(backing_store, byte_length);
buffer.set_backing_store(reinterpret_cast<void*>(Smi::FromInt(ref).ptr()));
uint32_t ref = SerializeBackingStore(backing_store, byte_length);
// To properly share the buffer, we set the backing store ref as an
// a backing store address. On deserialization we re-set data pointer
// to proper value.
buffer.set_backing_store(reinterpret_cast<void*>(static_cast<size_t>(ref)));
}
SerializeObject();
buffer.set_backing_store(backing_store);

2
src/snapshot/serializer.h
View File

@ -328,7 +328,7 @@ class Serializer::ObjectSerializer : public ObjectVisitor {
void SerializeContent(Map map, int size);
void OutputRawData(Address up_to);
void OutputCode(int size);
int32_t SerializeBackingStore(void* backing_store, int32_t byte_length);
uint32_t SerializeBackingStore(void* backing_store, int32_t byte_length);
void SerializeJSTypedArray();
void SerializeJSArrayBuffer();
void SerializeExternalString();