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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
*
* Copyright 2016 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "wasm/WasmInstance-inl.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/DebugOnly.h"
#include <algorithm>
#include <utility>
#include "jsmath.h"
#include "builtin/String.h"
#include "gc/Barrier.h"
#include "gc/Marking.h"
#include "jit/AtomicOperations.h"
#include "jit/Disassemble.h"
#include "jit/JitCommon.h"
#include "jit/JitRuntime.h"
#include "jit/Registers.h"
#include "js/ForOfIterator.h"
#include "js/friend/ErrorMessages.h" // js::GetErrorMessage, JSMSG_*
#include "js/Stack.h" // JS::NativeStackLimitMin
#include "util/StringBuffer.h"
#include "util/Text.h"
#include "util/Unicode.h"
#include "vm/ArrayBufferObject.h"
#include "vm/BigIntType.h"
#include "vm/Compartment.h"
#include "vm/ErrorObject.h"
#include "vm/Interpreter.h"
#include "vm/Iteration.h"
#include "vm/JitActivation.h"
#include "vm/JSFunction.h"
#include "vm/PlainObject.h" // js::PlainObject
#include "wasm/WasmBuiltins.h"
#include "wasm/WasmCode.h"
#include "wasm/WasmDebug.h"
#include "wasm/WasmDebugFrame.h"
#include "wasm/WasmFeatures.h"
#include "wasm/WasmInitExpr.h"
#include "wasm/WasmJS.h"
#include "wasm/WasmMemory.h"
#include "wasm/WasmModule.h"
#include "wasm/WasmModuleTypes.h"
#include "wasm/WasmPI.h"
#include "wasm/WasmStubs.h"
#include "wasm/WasmTypeDef.h"
#include "wasm/WasmValType.h"
#include "wasm/WasmValue.h"
#include "gc/Marking-inl.h"
#include "gc/StoreBuffer-inl.h"
#include "vm/ArrayBufferObject-inl.h"
#include "vm/JSObject-inl.h"
#include "wasm/WasmGcObject-inl.h"
using namespace js;
using namespace js::jit;
using namespace js::wasm;
using mozilla::BitwiseCast;
using mozilla::CheckedUint32;
using mozilla::DebugOnly;
// Instance must be aligned at least as much as any of the integer, float,
// or SIMD values that we'd like to store in it.
static_assert(alignof(Instance) >=
std::max(sizeof(Registers::RegisterContent),
sizeof(FloatRegisters::RegisterContent)));
// The globalArea must be aligned at least as much as an instance. This is
// guaranteed to be sufficient for all data types we care about, including
// SIMD values. See the above assertion.
static_assert(Instance::offsetOfData() % alignof(Instance) == 0);
// We want the memory base to be the first field, and accessible with no
// offset. This incidentally is also an assertion that there is no superclass
// with fields.
static_assert(Instance::offsetOfMemory0Base() == 0);
// We want instance fields that are commonly accessed by the JIT to have
// compact encodings. A limit of less than 128 bytes is chosen to fit within
// the signed 8-bit mod r/m x86 encoding.
static_assert(Instance::offsetOfLastCommonJitField() < 128);
//////////////////////////////////////////////////////////////////////////////
//
// Functions and invocation.
TypeDefInstanceData* Instance::typeDefInstanceData(uint32_t typeIndex) const {
TypeDefInstanceData* instanceData =
(TypeDefInstanceData*)(data() + metadata().typeDefsOffsetStart);
return &instanceData[typeIndex];
}
const void* Instance::addressOfGlobalCell(const GlobalDesc& global) const {
const void* cell = data() + global.offset();
// Indirect globals store a pointer to their cell in the instance global
// data. Dereference it to find the real cell.
if (global.isIndirect()) {
cell = *(const void**)cell;
}
return cell;
}
FuncImportInstanceData& Instance::funcImportInstanceData(const FuncImport& fi) {
return *(FuncImportInstanceData*)(data() + fi.instanceOffset());
}
MemoryInstanceData& Instance::memoryInstanceData(uint32_t memoryIndex) const {
MemoryInstanceData* instanceData =
(MemoryInstanceData*)(data() + metadata().memoriesOffsetStart);
return instanceData[memoryIndex];
}
TableInstanceData& Instance::tableInstanceData(uint32_t tableIndex) const {
TableInstanceData* instanceData =
(TableInstanceData*)(data() + metadata().tablesOffsetStart);
return instanceData[tableIndex];
}
TagInstanceData& Instance::tagInstanceData(uint32_t tagIndex) const {
TagInstanceData* instanceData =
(TagInstanceData*)(data() + metadata().tagsOffsetStart);
return instanceData[tagIndex];
}
static bool UnpackResults(JSContext* cx, const ValTypeVector& resultTypes,
const Maybe<char*> stackResultsArea, uint64_t* argv,
MutableHandleValue rval) {
if (!stackResultsArea) {
MOZ_ASSERT(resultTypes.length() <= 1);
// Result is either one scalar value to unpack to a wasm value, or
// an ignored value for a zero-valued function.
if (resultTypes.length() == 1) {
return ToWebAssemblyValue(cx, rval, resultTypes[0], argv, true);
}
return true;
}
MOZ_ASSERT(stackResultsArea.isSome());
Rooted<ArrayObject*> array(cx);
if (!IterableToArray(cx, rval, &array)) {
return false;
}
if (resultTypes.length() != array->length()) {
UniqueChars expected(JS_smprintf("%zu", resultTypes.length()));
UniqueChars got(JS_smprintf("%u", array->length()));
if (!expected || !got) {
ReportOutOfMemory(cx);
return false;
}
JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr,
JSMSG_WASM_WRONG_NUMBER_OF_VALUES, expected.get(),
got.get());
return false;
}
DebugOnly<uint64_t> previousOffset = ~(uint64_t)0;
ABIResultIter iter(ResultType::Vector(resultTypes));
// The values are converted in the order they are pushed on the
// abstract WebAssembly stack; switch to iterate in push order.
while (!iter.done()) {
iter.next();
}
DebugOnly<bool> seenRegisterResult = false;
for (iter.switchToPrev(); !iter.done(); iter.prev()) {
const ABIResult& result = iter.cur();
MOZ_ASSERT(!seenRegisterResult);
// Use rval as a scratch area to hold the extracted result.
rval.set(array->getDenseElement(iter.index()));
if (result.inRegister()) {
// Currently, if a function type has results, there can be only
// one register result. If there is only one result, it is
// returned as a scalar and not an iterable, so we don't get here.
// If there are multiple results, we extract the register result
// and set `argv[0]` set to the extracted result, to be returned by
// register in the stub. The register result follows any stack
// results, so this preserves conversion order.
if (!ToWebAssemblyValue(cx, rval, result.type(), argv, true)) {
return false;
}
seenRegisterResult = true;
continue;
}
uint32_t result_size = result.size();
MOZ_ASSERT(result_size == 4 || result_size == 8);
#ifdef DEBUG
if (previousOffset == ~(uint64_t)0) {
previousOffset = (uint64_t)result.stackOffset();
} else {
MOZ_ASSERT(previousOffset - (uint64_t)result_size ==
(uint64_t)result.stackOffset());
previousOffset -= (uint64_t)result_size;
}
#endif
char* loc = stackResultsArea.value() + result.stackOffset();
if (!ToWebAssemblyValue(cx, rval, result.type(), loc, result_size == 8)) {
return false;
}
}
return true;
}
bool Instance::callImport(JSContext* cx, uint32_t funcImportIndex,
unsigned argc, uint64_t* argv) {
AssertRealmUnchanged aru(cx);
Tier tier = code().bestTier();
const FuncImport& fi = metadata(tier).funcImports[funcImportIndex];
const FuncType& funcType = metadata().getFuncImportType(fi);
ArgTypeVector argTypes(funcType);
InvokeArgs args(cx);
if (!args.init(cx, argTypes.lengthWithoutStackResults())) {
return false;
}
if (funcType.hasUnexposableArgOrRet()) {
JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr,
JSMSG_WASM_BAD_VAL_TYPE);
return false;
}
MOZ_ASSERT(argTypes.lengthWithStackResults() == argc);
Maybe<char*> stackResultPointer;
size_t lastBoxIndexPlusOne = 0;
{
JS::AutoAssertNoGC nogc;
for (size_t i = 0; i < argc; i++) {
const void* rawArgLoc = &argv[i];
if (argTypes.isSyntheticStackResultPointerArg(i)) {
stackResultPointer = Some(*(char**)rawArgLoc);
continue;
}
size_t naturalIndex = argTypes.naturalIndex(i);
ValType type = funcType.args()[naturalIndex];
// Avoid boxes creation not to trigger GC.
if (ToJSValueMayGC(type)) {
lastBoxIndexPlusOne = i + 1;
continue;
}
MutableHandleValue argValue = args[naturalIndex];
if (!ToJSValue(cx, rawArgLoc, type, argValue)) {
return false;
}
}
}
// Visit arguments that need to perform allocation in a second loop
// after the rest of arguments are converted.
for (size_t i = 0; i < lastBoxIndexPlusOne; i++) {
if (argTypes.isSyntheticStackResultPointerArg(i)) {
continue;
}
const void* rawArgLoc = &argv[i];
size_t naturalIndex = argTypes.naturalIndex(i);
ValType type = funcType.args()[naturalIndex];
if (!ToJSValueMayGC(type)) {
continue;
}
MOZ_ASSERT(!type.isRefRepr());
// The conversions are safe here because source values are not references
// and will not be moved.
MutableHandleValue argValue = args[naturalIndex];
if (!ToJSValue(cx, rawArgLoc, type, argValue)) {
return false;
}
}
FuncImportInstanceData& import = funcImportInstanceData(fi);
Rooted<JSObject*> importCallable(cx, import.callable);
MOZ_ASSERT(cx->realm() == importCallable->nonCCWRealm());
RootedValue fval(cx, ObjectValue(*importCallable));
RootedValue thisv(cx, UndefinedValue());
RootedValue rval(cx);
if (!Call(cx, fval, thisv, args, &rval)) {
return false;
}
if (!UnpackResults(cx, funcType.results(), stackResultPointer, argv, &rval)) {
return false;
}
if (!JitOptions.enableWasmJitExit) {
return true;
}
#ifdef ENABLE_WASM_JSPI
// Disable jit exit optimization when JSPI is enabled.
if (JSPromiseIntegrationAvailable(cx)) {
return true;
}
#endif
// The import may already have become optimized.
for (auto t : code().tiers()) {
void* jitExitCode = codeBase(t) + fi.jitExitCodeOffset();
if (import.code == jitExitCode) {
return true;
}
}
void* jitExitCode = codeBase(tier) + fi.jitExitCodeOffset();
if (!importCallable->is<JSFunction>()) {
return true;
}
// Test if the function is JIT compiled.
if (!importCallable->as<JSFunction>().hasBytecode()) {
return true;
}
JSScript* script = importCallable->as<JSFunction>().nonLazyScript();
if (!script->hasJitScript()) {
return true;
}
// Skip if the function does not have a signature that allows for a JIT exit.
if (!funcType.canHaveJitExit()) {
return true;
}
// Let's optimize it!
import.code = jitExitCode;
return true;
}
#ifdef ENABLE_WASM_JSPI
bool Instance::isImportAllowedOnSuspendableStack(JSContext* cx,
int32_t funcImportIndex) {
Tier tier = code().bestTier();
const FuncImport& fi = metadata(tier).funcImports[funcImportIndex];
FuncImportInstanceData& import = funcImportInstanceData(fi);
Rooted<JSFunction*> fn(cx, &import.callable->as<JSFunction>());
return IsAllowedOnSuspendableStack(fn);
}
#endif
/* static */ int32_t /* 0 to signal trap; 1 to signal OK */
Instance::callImport_general(Instance* instance, int32_t funcImportIndex,
int32_t argc, uint64_t* argv) {
JSContext* cx = instance->cx();
#ifndef ENABLE_WASM_JSPI
return instance->callImport(cx, funcImportIndex, argc, argv);
#else
if (!IsSuspendableStackActive(cx) ||
instance->isImportAllowedOnSuspendableStack(cx, funcImportIndex)) {
return instance->callImport(cx, funcImportIndex, argc, argv);
}
return CallImportOnMainThread(cx, instance, funcImportIndex, argc, argv);
#endif
}
//////////////////////////////////////////////////////////////////////////////
//
// Atomic operations and shared memory.
template <typename ValT, typename PtrT>
static int32_t PerformWait(Instance* instance, uint32_t memoryIndex,
PtrT byteOffset, ValT value, int64_t timeout_ns) {
JSContext* cx = instance->cx();
if (!instance->memory(memoryIndex)->isShared()) {
ReportTrapError(cx, JSMSG_WASM_NONSHARED_WAIT);
return -1;
}
if (byteOffset & (sizeof(ValT) - 1)) {
ReportTrapError(cx, JSMSG_WASM_UNALIGNED_ACCESS);
return -1;
}
if (byteOffset + sizeof(ValT) >
instance->memory(memoryIndex)->volatileMemoryLength()) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
mozilla::Maybe<mozilla::TimeDuration> timeout;
if (timeout_ns >= 0) {
timeout = mozilla::Some(
mozilla::TimeDuration::FromMicroseconds(double(timeout_ns) / 1000));
}
MOZ_ASSERT(byteOffset <= SIZE_MAX, "Bounds check is broken");
switch (atomics_wait_impl(cx, instance->sharedMemoryBuffer(memoryIndex),
size_t(byteOffset), value, timeout)) {
case FutexThread::WaitResult::OK:
return 0;
case FutexThread::WaitResult::NotEqual:
return 1;
case FutexThread::WaitResult::TimedOut:
return 2;
case FutexThread::WaitResult::Error:
return -1;
default:
MOZ_CRASH();
}
}
/* static */ int32_t Instance::wait_i32_m32(Instance* instance,
uint32_t byteOffset, int32_t value,
int64_t timeout_ns,
uint32_t memoryIndex) {
MOZ_ASSERT(SASigWaitI32M32.failureMode == FailureMode::FailOnNegI32);
return PerformWait(instance, memoryIndex, byteOffset, value, timeout_ns);
}
/* static */ int32_t Instance::wait_i32_m64(Instance* instance,
uint64_t byteOffset, int32_t value,
int64_t timeout_ns,
uint32_t memoryIndex) {
MOZ_ASSERT(SASigWaitI32M64.failureMode == FailureMode::FailOnNegI32);
return PerformWait(instance, memoryIndex, byteOffset, value, timeout_ns);
}
/* static */ int32_t Instance::wait_i64_m32(Instance* instance,
uint32_t byteOffset, int64_t value,
int64_t timeout_ns,
uint32_t memoryIndex) {
MOZ_ASSERT(SASigWaitI64M32.failureMode == FailureMode::FailOnNegI32);
return PerformWait(instance, memoryIndex, byteOffset, value, timeout_ns);
}
/* static */ int32_t Instance::wait_i64_m64(Instance* instance,
uint64_t byteOffset, int64_t value,
int64_t timeout_ns,
uint32_t memoryIndex) {
MOZ_ASSERT(SASigWaitI64M64.failureMode == FailureMode::FailOnNegI32);
return PerformWait(instance, memoryIndex, byteOffset, value, timeout_ns);
}
template <typename PtrT>
static int32_t PerformWake(Instance* instance, PtrT byteOffset, int32_t count,
uint32_t memoryIndex) {
JSContext* cx = instance->cx();
// The alignment guard is not in the wasm spec as of 2017-11-02, but is
// considered likely to appear, as 4-byte alignment is required for WAKE by
// the spec's validation algorithm.
if (byteOffset & 3) {
ReportTrapError(cx, JSMSG_WASM_UNALIGNED_ACCESS);
return -1;
}
if (byteOffset >= instance->memory(memoryIndex)->volatileMemoryLength()) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
if (!instance->memory(memoryIndex)->isShared()) {
return 0;
}
MOZ_ASSERT(byteOffset <= SIZE_MAX, "Bounds check is broken");
int64_t woken = atomics_notify_impl(instance->sharedMemoryBuffer(memoryIndex),
size_t(byteOffset), int64_t(count));
if (woken > INT32_MAX) {
ReportTrapError(cx, JSMSG_WASM_WAKE_OVERFLOW);
return -1;
}
return int32_t(woken);
}
/* static */ int32_t Instance::wake_m32(Instance* instance, uint32_t byteOffset,
int32_t count, uint32_t memoryIndex) {
MOZ_ASSERT(SASigWakeM32.failureMode == FailureMode::FailOnNegI32);
return PerformWake(instance, byteOffset, count, memoryIndex);
}
/* static */ int32_t Instance::wake_m64(Instance* instance, uint64_t byteOffset,
int32_t count, uint32_t memoryIndex) {
MOZ_ASSERT(SASigWakeM32.failureMode == FailureMode::FailOnNegI32);
return PerformWake(instance, byteOffset, count, memoryIndex);
}
//////////////////////////////////////////////////////////////////////////////
//
// Bulk memory operations.
/* static */ uint32_t Instance::memoryGrow_m32(Instance* instance,
uint32_t delta,
uint32_t memoryIndex) {
MOZ_ASSERT(SASigMemoryGrowM32.failureMode == FailureMode::Infallible);
MOZ_ASSERT(!instance->isAsmJS());
JSContext* cx = instance->cx();
Rooted<WasmMemoryObject*> memory(cx, instance->memory(memoryIndex));
// It is safe to cast to uint32_t, as all limits have been checked inside
// grow() and will not have been exceeded for a 32-bit memory.
uint32_t ret = uint32_t(WasmMemoryObject::grow(memory, uint64_t(delta), cx));
// If there has been a moving grow, this Instance should have been notified.
MOZ_RELEASE_ASSERT(
instance->memoryBase(memoryIndex) ==
instance->memory(memoryIndex)->buffer().dataPointerEither());
return ret;
}
/* static */ uint64_t Instance::memoryGrow_m64(Instance* instance,
uint64_t delta,
uint32_t memoryIndex) {
MOZ_ASSERT(SASigMemoryGrowM64.failureMode == FailureMode::Infallible);
MOZ_ASSERT(!instance->isAsmJS());
JSContext* cx = instance->cx();
Rooted<WasmMemoryObject*> memory(cx, instance->memory(memoryIndex));
uint64_t ret = WasmMemoryObject::grow(memory, delta, cx);
// If there has been a moving grow, this Instance should have been notified.
MOZ_RELEASE_ASSERT(
instance->memoryBase(memoryIndex) ==
instance->memory(memoryIndex)->buffer().dataPointerEither());
return ret;
}
/* static */ uint32_t Instance::memorySize_m32(Instance* instance,
uint32_t memoryIndex) {
MOZ_ASSERT(SASigMemorySizeM32.failureMode == FailureMode::Infallible);
// This invariant must hold when running Wasm code. Assert it here so we can
// write tests for cross-realm calls.
DebugOnly<JSContext*> cx = instance->cx();
MOZ_ASSERT(cx->realm() == instance->realm());
Pages pages = instance->memory(memoryIndex)->volatilePages();
#ifdef JS_64BIT
// Ensure that the memory size is no more than 4GiB.
MOZ_ASSERT(pages <= Pages(MaxMemory32LimitField));
#endif
return uint32_t(pages.value());
}
/* static */ uint64_t Instance::memorySize_m64(Instance* instance,
uint32_t memoryIndex) {
MOZ_ASSERT(SASigMemorySizeM64.failureMode == FailureMode::Infallible);
// This invariant must hold when running Wasm code. Assert it here so we can
// write tests for cross-realm calls.
DebugOnly<JSContext*> cx = instance->cx();
MOZ_ASSERT(cx->realm() == instance->realm());
Pages pages = instance->memory(memoryIndex)->volatilePages();
#ifdef JS_64BIT
MOZ_ASSERT(pages <= Pages(MaxMemory64LimitField));
#endif
return pages.value();
}
template <typename PointerT, typename CopyFuncT, typename IndexT>
inline int32_t WasmMemoryCopy(JSContext* cx, PointerT dstMemBase,
PointerT srcMemBase, size_t dstMemLen,
size_t srcMemLen, IndexT dstByteOffset,
IndexT srcByteOffset, IndexT len,
CopyFuncT memMove) {
if (!MemoryBoundsCheck(dstByteOffset, len, dstMemLen) ||
!MemoryBoundsCheck(srcByteOffset, len, srcMemLen)) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
memMove(dstMemBase + uintptr_t(dstByteOffset),
srcMemBase + uintptr_t(srcByteOffset), size_t(len));
return 0;
}
template <typename I>
inline int32_t MemoryCopy(JSContext* cx, I dstByteOffset, I srcByteOffset,
I len, uint8_t* memBase) {
const WasmArrayRawBuffer* rawBuf = WasmArrayRawBuffer::fromDataPtr(memBase);
size_t memLen = rawBuf->byteLength();
return WasmMemoryCopy(cx, memBase, memBase, memLen, memLen, dstByteOffset,
srcByteOffset, len, memmove);
}
template <typename I>
inline int32_t MemoryCopyShared(JSContext* cx, I dstByteOffset, I srcByteOffset,
I len, uint8_t* memBase) {
using RacyMemMove =
void (*)(SharedMem<uint8_t*>, SharedMem<uint8_t*>, size_t);
const WasmSharedArrayRawBuffer* rawBuf =
WasmSharedArrayRawBuffer::fromDataPtr(memBase);
size_t memLen = rawBuf->volatileByteLength();
SharedMem<uint8_t*> sharedMemBase = SharedMem<uint8_t*>::shared(memBase);
return WasmMemoryCopy<SharedMem<uint8_t*>, RacyMemMove>(
cx, sharedMemBase, sharedMemBase, memLen, memLen, dstByteOffset,
srcByteOffset, len, AtomicOperations::memmoveSafeWhenRacy);
}
/* static */ int32_t Instance::memCopy_m32(Instance* instance,
uint32_t dstByteOffset,
uint32_t srcByteOffset, uint32_t len,
uint8_t* memBase) {
MOZ_ASSERT(SASigMemCopyM32.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
return MemoryCopy(cx, dstByteOffset, srcByteOffset, len, memBase);
}
/* static */ int32_t Instance::memCopyShared_m32(Instance* instance,
uint32_t dstByteOffset,
uint32_t srcByteOffset,
uint32_t len,
uint8_t* memBase) {
MOZ_ASSERT(SASigMemCopySharedM32.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
return MemoryCopyShared(cx, dstByteOffset, srcByteOffset, len, memBase);
}
/* static */ int32_t Instance::memCopy_m64(Instance* instance,
uint64_t dstByteOffset,
uint64_t srcByteOffset, uint64_t len,
uint8_t* memBase) {
MOZ_ASSERT(SASigMemCopyM64.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
return MemoryCopy(cx, dstByteOffset, srcByteOffset, len, memBase);
}
/* static */ int32_t Instance::memCopyShared_m64(Instance* instance,
uint64_t dstByteOffset,
uint64_t srcByteOffset,
uint64_t len,
uint8_t* memBase) {
MOZ_ASSERT(SASigMemCopySharedM64.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
return MemoryCopyShared(cx, dstByteOffset, srcByteOffset, len, memBase);
}
// Dynamic dispatch to get the length of a memory given just the base and
// whether it is shared or not. This is only used for memCopy_any, where being
// slower is okay.
static inline size_t GetVolatileByteLength(uint8_t* memBase, bool isShared) {
if (isShared) {
return WasmSharedArrayRawBuffer::fromDataPtr(memBase)->volatileByteLength();
}
return WasmArrayRawBuffer::fromDataPtr(memBase)->byteLength();
}
/* static */ int32_t Instance::memCopy_any(Instance* instance,
uint64_t dstByteOffset,
uint64_t srcByteOffset, uint64_t len,
uint32_t dstMemIndex,
uint32_t srcMemIndex) {
MOZ_ASSERT(SASigMemCopyAny.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
using RacyMemMove =
void (*)(SharedMem<uint8_t*>, SharedMem<uint8_t*>, size_t);
const MemoryInstanceData& dstMemory =
instance->memoryInstanceData(dstMemIndex);
const MemoryInstanceData& srcMemory =
instance->memoryInstanceData(srcMemIndex);
uint8_t* dstMemBase = dstMemory.base;
uint8_t* srcMemBase = srcMemory.base;
size_t dstMemLen = GetVolatileByteLength(dstMemBase, dstMemory.isShared);
size_t srcMemLen = GetVolatileByteLength(srcMemBase, srcMemory.isShared);
return WasmMemoryCopy<SharedMem<uint8_t*>, RacyMemMove>(
cx, SharedMem<uint8_t*>::shared(dstMemBase),
SharedMem<uint8_t*>::shared(srcMemBase), dstMemLen, srcMemLen,
dstByteOffset, srcByteOffset, len, AtomicOperations::memmoveSafeWhenRacy);
}
template <typename T, typename F, typename I>
inline int32_t WasmMemoryFill(JSContext* cx, T memBase, size_t memLen,
I byteOffset, uint32_t value, I len, F memSet) {
if (!MemoryBoundsCheck(byteOffset, len, memLen)) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
// The required write direction is upward, but that is not currently
// observable as there are no fences nor any read/write protect operation.
memSet(memBase + uintptr_t(byteOffset), int(value), size_t(len));
return 0;
}
template <typename I>
inline int32_t MemoryFill(JSContext* cx, I byteOffset, uint32_t value, I len,
uint8_t* memBase) {
const WasmArrayRawBuffer* rawBuf = WasmArrayRawBuffer::fromDataPtr(memBase);
size_t memLen = rawBuf->byteLength();
return WasmMemoryFill(cx, memBase, memLen, byteOffset, value, len, memset);
}
template <typename I>
inline int32_t MemoryFillShared(JSContext* cx, I byteOffset, uint32_t value,
I len, uint8_t* memBase) {
const WasmSharedArrayRawBuffer* rawBuf =
WasmSharedArrayRawBuffer::fromDataPtr(memBase);
size_t memLen = rawBuf->volatileByteLength();
return WasmMemoryFill(cx, SharedMem<uint8_t*>::shared(memBase), memLen,
byteOffset, value, len,
AtomicOperations::memsetSafeWhenRacy);
}
/* static */ int32_t Instance::memFill_m32(Instance* instance,
uint32_t byteOffset, uint32_t value,
uint32_t len, uint8_t* memBase) {
MOZ_ASSERT(SASigMemFillM32.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
return MemoryFill(cx, byteOffset, value, len, memBase);
}
/* static */ int32_t Instance::memFillShared_m32(Instance* instance,
uint32_t byteOffset,
uint32_t value, uint32_t len,
uint8_t* memBase) {
MOZ_ASSERT(SASigMemFillSharedM32.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
return MemoryFillShared(cx, byteOffset, value, len, memBase);
}
/* static */ int32_t Instance::memFill_m64(Instance* instance,
uint64_t byteOffset, uint32_t value,
uint64_t len, uint8_t* memBase) {
MOZ_ASSERT(SASigMemFillM64.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
return MemoryFill(cx, byteOffset, value, len, memBase);
}
/* static */ int32_t Instance::memFillShared_m64(Instance* instance,
uint64_t byteOffset,
uint32_t value, uint64_t len,
uint8_t* memBase) {
MOZ_ASSERT(SASigMemFillSharedM64.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
return MemoryFillShared(cx, byteOffset, value, len, memBase);
}
static bool BoundsCheckInit(uint32_t dstOffset, uint32_t srcOffset,
uint32_t len, size_t memLen, uint32_t segLen) {
uint64_t dstOffsetLimit = uint64_t(dstOffset) + uint64_t(len);
uint64_t srcOffsetLimit = uint64_t(srcOffset) + uint64_t(len);
return dstOffsetLimit > memLen || srcOffsetLimit > segLen;
}
static bool BoundsCheckInit(uint64_t dstOffset, uint32_t srcOffset,
uint32_t len, size_t memLen, uint32_t segLen) {
uint64_t dstOffsetLimit = dstOffset + uint64_t(len);
uint64_t srcOffsetLimit = uint64_t(srcOffset) + uint64_t(len);
return dstOffsetLimit < dstOffset || dstOffsetLimit > memLen ||
srcOffsetLimit > segLen;
}
template <typename I>
static int32_t MemoryInit(JSContext* cx, Instance* instance,
uint32_t memoryIndex, I dstOffset, uint32_t srcOffset,
uint32_t len, const DataSegment* maybeSeg) {
if (!maybeSeg) {
if (len == 0 && srcOffset == 0) {
return 0;
}
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
const DataSegment& seg = *maybeSeg;
MOZ_RELEASE_ASSERT(!seg.active());
const uint32_t segLen = seg.bytes.length();
WasmMemoryObject* mem = instance->memory(memoryIndex);
const size_t memLen = mem->volatileMemoryLength();
// We are proposing to copy
//
// seg.bytes.begin()[ srcOffset .. srcOffset + len - 1 ]
// to
// memoryBase[ dstOffset .. dstOffset + len - 1 ]
if (BoundsCheckInit(dstOffset, srcOffset, len, memLen, segLen)) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
// The required read/write direction is upward, but that is not currently
// observable as there are no fences nor any read/write protect operation.
SharedMem<uint8_t*> dataPtr = mem->buffer().dataPointerEither();
if (mem->isShared()) {
AtomicOperations::memcpySafeWhenRacy(
dataPtr + uintptr_t(dstOffset), (uint8_t*)seg.bytes.begin() + srcOffset,
len);
} else {
uint8_t* rawBuf = dataPtr.unwrap(/*Unshared*/);
memcpy(rawBuf + uintptr_t(dstOffset),
(const char*)seg.bytes.begin() + srcOffset, len);
}
return 0;
}
/* static */ int32_t Instance::memInit_m32(Instance* instance,
uint32_t dstOffset,
uint32_t srcOffset, uint32_t len,
uint32_t segIndex,
uint32_t memIndex) {
MOZ_ASSERT(SASigMemInitM32.failureMode == FailureMode::FailOnNegI32);
MOZ_RELEASE_ASSERT(size_t(segIndex) < instance->passiveDataSegments_.length(),
"ensured by validation");
JSContext* cx = instance->cx();
return MemoryInit(cx, instance, memIndex, dstOffset, srcOffset, len,
instance->passiveDataSegments_[segIndex]);
}
/* static */ int32_t Instance::memInit_m64(Instance* instance,
uint64_t dstOffset,
uint32_t srcOffset, uint32_t len,
uint32_t segIndex,
uint32_t memIndex) {
MOZ_ASSERT(SASigMemInitM64.failureMode == FailureMode::FailOnNegI32);
MOZ_RELEASE_ASSERT(size_t(segIndex) < instance->passiveDataSegments_.length(),
"ensured by validation");
JSContext* cx = instance->cx();
return MemoryInit(cx, instance, memIndex, dstOffset, srcOffset, len,
instance->passiveDataSegments_[segIndex]);
}
//////////////////////////////////////////////////////////////////////////////
//
// Bulk table operations.
/* static */ int32_t Instance::tableCopy(Instance* instance, uint32_t dstOffset,
uint32_t srcOffset, uint32_t len,
uint32_t dstTableIndex,
uint32_t srcTableIndex) {
MOZ_ASSERT(SASigTableCopy.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
const SharedTable& srcTable = instance->tables()[srcTableIndex];
uint32_t srcTableLen = srcTable->length();
const SharedTable& dstTable = instance->tables()[dstTableIndex];
uint32_t dstTableLen = dstTable->length();
// Bounds check and deal with arithmetic overflow.
uint64_t dstOffsetLimit = uint64_t(dstOffset) + len;
uint64_t srcOffsetLimit = uint64_t(srcOffset) + len;
if (dstOffsetLimit > dstTableLen || srcOffsetLimit > srcTableLen) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
bool isOOM = false;
if (&srcTable == &dstTable && dstOffset > srcOffset) {
for (uint32_t i = len; i > 0; i--) {
if (!dstTable->copy(cx, *srcTable, dstOffset + (i - 1),
srcOffset + (i - 1))) {
isOOM = true;
break;
}
}
} else if (&srcTable == &dstTable && dstOffset == srcOffset) {
// No-op
} else {
for (uint32_t i = 0; i < len; i++) {
if (!dstTable->copy(cx, *srcTable, dstOffset + i, srcOffset + i)) {
isOOM = true;
break;
}
}
}
if (isOOM) {
return -1;
}
return 0;
}
#ifdef DEBUG
static bool AllSegmentsArePassive(const DataSegmentVector& vec) {
for (const DataSegment* seg : vec) {
if (seg->active()) {
return false;
}
}
return true;
}
#endif
bool Instance::initSegments(JSContext* cx,
const DataSegmentVector& dataSegments,
const ModuleElemSegmentVector& elemSegments) {
MOZ_ASSERT_IF(metadata().memories.length() == 0,
AllSegmentsArePassive(dataSegments));
Rooted<WasmInstanceObject*> instanceObj(cx, object());
// Write data/elem segments into memories/tables.
for (const ModuleElemSegment& seg : elemSegments) {
if (seg.active()) {
RootedVal offsetVal(cx);
if (!seg.offset().evaluate(cx, instanceObj, &offsetVal)) {
return false; // OOM
}
uint32_t offset = offsetVal.get().i32();
uint32_t tableLength = tables()[seg.tableIndex]->length();
if (offset > tableLength || tableLength - offset < seg.numElements()) {
JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr,
JSMSG_WASM_OUT_OF_BOUNDS);
return false;
}
if (!initElems(seg.tableIndex, seg, offset)) {
return false; // OOM
}
}
}
for (const DataSegment* seg : dataSegments) {
if (!seg->active()) {
continue;
}
Rooted<const WasmMemoryObject*> memoryObj(cx, memory(seg->memoryIndex));
size_t memoryLength = memoryObj->volatileMemoryLength();
uint8_t* memoryBase =
memoryObj->buffer().dataPointerEither().unwrap(/* memcpy */);
RootedVal offsetVal(cx);
if (!seg->offset().evaluate(cx, instanceObj, &offsetVal)) {
return false; // OOM
}
uint64_t offset = memoryObj->indexType() == IndexType::I32
? offsetVal.get().i32()
: offsetVal.get().i64();
uint32_t count = seg->bytes.length();
if (offset > memoryLength || memoryLength - offset < count) {
JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr,
JSMSG_WASM_OUT_OF_BOUNDS);
return false;
}
memcpy(memoryBase + uintptr_t(offset), seg->bytes.begin(), count);
}
return true;
}
bool Instance::initElems(uint32_t tableIndex, const ModuleElemSegment& seg,
uint32_t dstOffset) {
Table& table = *tables_[tableIndex];
MOZ_ASSERT(dstOffset <= table.length());
MOZ_ASSERT(seg.numElements() <= table.length() - dstOffset);
if (seg.numElements() == 0) {
return true;
}
Rooted<WasmInstanceObject*> instanceObj(cx(), object());
if (table.isFunction() &&
seg.encoding == ModuleElemSegment::Encoding::Indices) {
// Initialize this table of functions without creating any intermediate
// JSFunctions.
bool ok = iterElemsFunctions(
seg, [&](uint32_t i, void* code, Instance* instance) -> bool {
table.setFuncRef(dstOffset + i, code, instance);
return true;
});
if (!ok) {
return false;
}
} else {
bool ok = iterElemsAnyrefs(seg, [&](uint32_t i, AnyRef ref) -> bool {
table.setRef(dstOffset + i, ref);
return true;
});
if (!ok) {
return false;
}
}
return true;
}
template <typename F>
bool Instance::iterElemsFunctions(const ModuleElemSegment& seg,
const F& onFunc) {
// In the future, we could theoretically get function data (instance + code
// pointer) from segments with the expression encoding without creating
// JSFunctions. But that is not how it works today. We can only bypass the
// creation of JSFunctions for the index encoding.
MOZ_ASSERT(seg.encoding == ModuleElemSegment::Encoding::Indices);
if (seg.numElements() == 0) {
return true;
}
Tier tier = code().bestTier();
const MetadataTier& metadataTier = metadata(tier);
const FuncImportVector& funcImports = metadataTier.funcImports;
const CodeRangeVector& codeRanges = metadataTier.codeRanges;
const Uint32Vector& funcToCodeRange = metadataTier.funcToCodeRange;
const Uint32Vector& elemIndices = seg.elemIndices;
uint8_t* codeBaseTier = codeBase(tier);
for (uint32_t i = 0; i < seg.numElements(); i++) {
uint32_t elemIndex = elemIndices[i];
if (elemIndex < metadataTier.funcImports.length()) {
FuncImportInstanceData& import =
funcImportInstanceData(funcImports[elemIndex]);
MOZ_ASSERT(import.callable->isCallable());
if (import.callable->is<JSFunction>()) {
JSFunction* fun = &import.callable->as<JSFunction>();
if (IsWasmExportedFunction(fun)) {
// This element is a wasm function imported from another
// instance. To preserve the === function identity required by
// the JS embedding spec, we must get the imported function's
// underlying CodeRange.funcCheckedCallEntry and Instance so that
// future Table.get()s produce the same function object as was
// imported.
WasmInstanceObject* calleeInstanceObj =
ExportedFunctionToInstanceObject(fun);
Instance& calleeInstance = calleeInstanceObj->instance();
Tier calleeTier = calleeInstance.code().bestTier();
const CodeRange& calleeCodeRange =
calleeInstanceObj->getExportedFunctionCodeRange(fun, calleeTier);
void* code = calleeInstance.codeBase(calleeTier) +
calleeCodeRange.funcCheckedCallEntry();
if (!onFunc(i, code, &calleeInstance)) {
return false;
}
continue;
}
}
}
void* code = codeBaseTier +
codeRanges[funcToCodeRange[elemIndex]].funcCheckedCallEntry();
if (!onFunc(i, code, this)) {
return false;
}
}
return true;
}
template <typename F>
bool Instance::iterElemsAnyrefs(const ModuleElemSegment& seg,
const F& onAnyRef) {
if (seg.numElements() == 0) {
return true;
}
switch (seg.encoding) {
case ModuleElemSegment::Encoding::Indices: {
// The only types of indices that exist right now are function indices, so
// this code is specialized to functions.
for (uint32_t i = 0; i < seg.numElements(); i++) {
uint32_t funcIndex = seg.elemIndices[i];
// Note, fnref must be rooted if we do anything more than just store it.
void* fnref = Instance::refFunc(this, funcIndex);
if (fnref == AnyRef::invalid().forCompiledCode()) {
return false; // OOM, which has already been reported.
}
if (!onAnyRef(i, AnyRef::fromCompiledCode(fnref))) {
return false;
}
}
} break;
case ModuleElemSegment::Encoding::Expressions: {
Rooted<WasmInstanceObject*> instanceObj(cx(), object());
const ModuleElemSegment::Expressions& exprs = seg.elemExpressions;
UniqueChars error;
// The offset is a dummy because the expression has already been
// validated.
Decoder d(exprs.exprBytes.begin(), exprs.exprBytes.end(), 0, &error);
for (uint32_t i = 0; i < seg.numElements(); i++) {
RootedVal result(cx());
if (!InitExpr::decodeAndEvaluate(cx(), instanceObj, d, seg.elemType,
&result)) {
MOZ_ASSERT(!error); // The only possible failure should be OOM.
return false;
}
// We would need to root this AnyRef if we were doing anything other
// than storing it.
AnyRef ref = result.get().ref();
if (!onAnyRef(i, ref)) {
return false;
}
}
} break;
default:
MOZ_CRASH("unknown encoding type for element segment");
}
return true;
}
/* static */ int32_t Instance::tableInit(Instance* instance, uint32_t dstOffset,
uint32_t srcOffset, uint32_t len,
uint32_t segIndex,
uint32_t tableIndex) {
MOZ_ASSERT(SASigTableInit.failureMode == FailureMode::FailOnNegI32);
MOZ_RELEASE_ASSERT(size_t(segIndex) < instance->passiveElemSegments_.length(),
"ensured by validation");
JSContext* cx = instance->cx();
const InstanceElemSegment& seg = instance->passiveElemSegments_[segIndex];
const uint32_t segLen = seg.length();
Table& table = *instance->tables()[tableIndex];
const uint32_t tableLen = table.length();
// We are proposing to copy
//
// seg[ srcOffset .. srcOffset + len - 1 ]
// to
// tableBase[ dstOffset .. dstOffset + len - 1 ]
// Bounds check and deal with arithmetic overflow.
uint64_t dstOffsetLimit = uint64_t(dstOffset) + uint64_t(len);
uint64_t srcOffsetLimit = uint64_t(srcOffset) + uint64_t(len);
if (dstOffsetLimit > tableLen || srcOffsetLimit > segLen) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
for (size_t i = 0; i < len; i++) {
table.setRef(dstOffset + i, seg[srcOffset + i]);
}
return 0;
}
/* static */ int32_t Instance::tableFill(Instance* instance, uint32_t start,
void* value, uint32_t len,
uint32_t tableIndex) {
MOZ_ASSERT(SASigTableFill.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
Table& table = *instance->tables()[tableIndex];
// Bounds check and deal with arithmetic overflow.
uint64_t offsetLimit = uint64_t(start) + uint64_t(len);
if (offsetLimit > table.length()) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
switch (table.repr()) {
case TableRepr::Ref:
table.fillAnyRef(start, len, AnyRef::fromCompiledCode(value));
break;
case TableRepr::Func:
MOZ_RELEASE_ASSERT(!table.isAsmJS());
table.fillFuncRef(start, len, FuncRef::fromCompiledCode(value), cx);
break;
}
return 0;
}
template <typename I>
static bool WasmDiscardCheck(Instance* instance, I byteOffset, I byteLen,
size_t memLen, bool shared) {
JSContext* cx = instance->cx();
if (byteOffset % wasm::PageSize != 0 || byteLen % wasm::PageSize != 0) {
ReportTrapError(cx, JSMSG_WASM_UNALIGNED_ACCESS);
return false;
}
if (!MemoryBoundsCheck(byteOffset, byteLen, memLen)) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return false;
}
return true;
}
template <typename I>
static int32_t MemDiscardNotShared(Instance* instance, I byteOffset, I byteLen,
uint8_t* memBase) {
WasmArrayRawBuffer* rawBuf = WasmArrayRawBuffer::fromDataPtr(memBase);
size_t memLen = rawBuf->byteLength();
if (!WasmDiscardCheck(instance, byteOffset, byteLen, memLen, false)) {
return -1;
}
rawBuf->discard(byteOffset, byteLen);
return 0;
}
template <typename I>
static int32_t MemDiscardShared(Instance* instance, I byteOffset, I byteLen,
uint8_t* memBase) {
WasmSharedArrayRawBuffer* rawBuf =
WasmSharedArrayRawBuffer::fromDataPtr(memBase);
size_t memLen = rawBuf->volatileByteLength();
if (!WasmDiscardCheck(instance, byteOffset, byteLen, memLen, true)) {
return -1;
}
rawBuf->discard(byteOffset, byteLen);
return 0;
}
/* static */ int32_t Instance::memDiscard_m32(Instance* instance,
uint32_t byteOffset,
uint32_t byteLen,
uint8_t* memBase) {
return MemDiscardNotShared(instance, byteOffset, byteLen, memBase);
}
/* static */ int32_t Instance::memDiscard_m64(Instance* instance,
uint64_t byteOffset,
uint64_t byteLen,
uint8_t* memBase) {
return MemDiscardNotShared(instance, byteOffset, byteLen, memBase);
}
/* static */ int32_t Instance::memDiscardShared_m32(Instance* instance,
uint32_t byteOffset,
uint32_t byteLen,
uint8_t* memBase) {
return MemDiscardShared(instance, byteOffset, byteLen, memBase);
}
/* static */ int32_t Instance::memDiscardShared_m64(Instance* instance,
uint64_t byteOffset,
uint64_t byteLen,
uint8_t* memBase) {
return MemDiscardShared(instance, byteOffset, byteLen, memBase);
}
/* static */ void* Instance::tableGet(Instance* instance, uint32_t index,
uint32_t tableIndex) {
MOZ_ASSERT(SASigTableGet.failureMode == FailureMode::FailOnInvalidRef);
JSContext* cx = instance->cx();
const Table& table = *instance->tables()[tableIndex];
if (index >= table.length()) {
ReportTrapError(cx, JSMSG_WASM_TABLE_OUT_OF_BOUNDS);
return AnyRef::invalid().forCompiledCode();
}
switch (table.repr()) {
case TableRepr::Ref:
return table.getAnyRef(index).forCompiledCode();
case TableRepr::Func: {
MOZ_RELEASE_ASSERT(!table.isAsmJS());
RootedFunction fun(cx);
if (!table.getFuncRef(cx, index, &fun)) {
return AnyRef::invalid().forCompiledCode();
}
return FuncRef::fromJSFunction(fun).forCompiledCode();
}
}
MOZ_CRASH("Should not happen");
}
/* static */ uint32_t Instance::tableGrow(Instance* instance, void* initValue,
uint32_t delta, uint32_t tableIndex) {
MOZ_ASSERT(SASigTableGrow.failureMode == FailureMode::Infallible);
JSContext* cx = instance->cx();
RootedAnyRef ref(cx, AnyRef::fromCompiledCode(initValue));
Table& table = *instance->tables()[tableIndex];
uint32_t oldSize = table.grow(delta);
if (oldSize != uint32_t(-1) && initValue != nullptr) {
table.fillUninitialized(oldSize, delta, ref, cx);
}
#ifdef DEBUG
if (!table.elemType().isNullable()) {
table.assertRangeNotNull(oldSize, delta);
}
#endif // DEBUG
return oldSize;
}
/* static */ int32_t Instance::tableSet(Instance* instance, uint32_t index,
void* value, uint32_t tableIndex) {
MOZ_ASSERT(SASigTableSet.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
Table& table = *instance->tables()[tableIndex];
if (index >= table.length()) {
ReportTrapError(cx, JSMSG_WASM_TABLE_OUT_OF_BOUNDS);
return -1;
}
switch (table.repr()) {
case TableRepr::Ref:
table.setAnyRef(index, AnyRef::fromCompiledCode(value));
break;
case TableRepr::Func:
MOZ_RELEASE_ASSERT(!table.isAsmJS());
table.fillFuncRef(index, 1, FuncRef::fromCompiledCode(value), cx);
break;
}
return 0;
}
/* static */ uint32_t Instance::tableSize(Instance* instance,
uint32_t tableIndex) {
MOZ_ASSERT(SASigTableSize.failureMode == FailureMode::Infallible);
Table& table = *instance->tables()[tableIndex];
return table.length();
}
/* static */ void* Instance::refFunc(Instance* instance, uint32_t funcIndex) {
MOZ_ASSERT(SASigRefFunc.failureMode == FailureMode::FailOnInvalidRef);
JSContext* cx = instance->cx();
Tier tier = instance->code().bestTier();
const MetadataTier& metadataTier = instance->metadata(tier);
const FuncImportVector& funcImports = metadataTier.funcImports;
// If this is an import, we need to recover the original function to maintain
// reference equality between a re-exported function and 'ref.func'. The
// identity of the imported function object is stable across tiers, which is
// what we want.
//
// Use the imported function only if it is an exported function, otherwise
// fall through to get a (possibly new) exported function.
if (funcIndex < funcImports.length()) {
FuncImportInstanceData& import =
instance->funcImportInstanceData(funcImports[funcIndex]);
if (import.callable->is<JSFunction>()) {
JSFunction* fun = &import.callable->as<JSFunction>();
if (IsWasmExportedFunction(fun)) {
return FuncRef::fromJSFunction(fun).forCompiledCode();
}
}
}
RootedFunction fun(cx);
Rooted<WasmInstanceObject*> instanceObj(cx, instance->object());
if (!WasmInstanceObject::getExportedFunction(cx, instanceObj, funcIndex,
&fun)) {
// Validation ensures that we always have a valid funcIndex, so we must
// have OOM'ed
ReportOutOfMemory(cx);
return AnyRef::invalid().forCompiledCode();
}
return FuncRef::fromJSFunction(fun).forCompiledCode();
}
//////////////////////////////////////////////////////////////////////////////
//
// Segment management.
/* static */ int32_t Instance::elemDrop(Instance* instance, uint32_t segIndex) {
MOZ_ASSERT(SASigElemDrop.failureMode == FailureMode::FailOnNegI32);
MOZ_RELEASE_ASSERT(size_t(segIndex) < instance->passiveElemSegments_.length(),
"ensured by validation");
instance->passiveElemSegments_[segIndex].clearAndFree();
return 0;
}
/* static */ int32_t Instance::dataDrop(Instance* instance, uint32_t segIndex) {
MOZ_ASSERT(SASigDataDrop.failureMode == FailureMode::FailOnNegI32);
MOZ_RELEASE_ASSERT(size_t(segIndex) < instance->passiveDataSegments_.length(),
"ensured by validation");
if (!instance->passiveDataSegments_[segIndex]) {
return 0;
}
SharedDataSegment& segRefPtr = instance->passiveDataSegments_[segIndex];
MOZ_RELEASE_ASSERT(!segRefPtr->active());
// Drop this instance's reference to the DataSegment so it can be released.
segRefPtr = nullptr;
return 0;
}
//////////////////////////////////////////////////////////////////////////////
//
// AnyRef support.
/* static */ void Instance::postBarrier(Instance* instance, void** location) {
MOZ_ASSERT(SASigPostBarrier.failureMode == FailureMode::Infallible);
MOZ_ASSERT(location);
instance->storeBuffer_->putWasmAnyRef(
reinterpret_cast<wasm::AnyRef*>(location));
}
/* static */ void Instance::postBarrierPrecise(Instance* instance,
void** location, void* prev) {
MOZ_ASSERT(SASigPostBarrierPrecise.failureMode == FailureMode::Infallible);
postBarrierPreciseWithOffset(instance, location, /*offset=*/0, prev);
}
/* static */ void Instance::postBarrierPreciseWithOffset(Instance* instance,
void** base,
uint32_t offset,
void* prev) {
MOZ_ASSERT(SASigPostBarrierPreciseWithOffset.failureMode ==
FailureMode::Infallible);
MOZ_ASSERT(base);
wasm::AnyRef* location = (wasm::AnyRef*)(uintptr_t(base) + size_t(offset));
wasm::AnyRef next = *location;
InternalBarrierMethods<AnyRef>::postBarrier(
location, wasm::AnyRef::fromCompiledCode(prev), next);
}
//////////////////////////////////////////////////////////////////////////////
//
// GC and exception handling support.
/* static */
template <bool ZeroFields>
void* Instance::structNewIL(Instance* instance,
TypeDefInstanceData* typeDefData) {
MOZ_ASSERT((ZeroFields ? SASigStructNewIL_true : SASigStructNewIL_false)
.failureMode == FailureMode::FailOnNullPtr);
JSContext* cx = instance->cx();
// The new struct will be allocated in an initial heap as determined by
// pretenuring logic as set up in `Instance::init`.
return WasmStructObject::createStructIL<ZeroFields>(
cx, typeDefData, typeDefData->allocSite.initialHeap());
}
template void* Instance::structNewIL<true>(Instance* instance,
TypeDefInstanceData* typeDefData);
template void* Instance::structNewIL<false>(Instance* instance,
TypeDefInstanceData* typeDefData);
/* static */
template <bool ZeroFields>
void* Instance::structNewOOL(Instance* instance,
TypeDefInstanceData* typeDefData) {
MOZ_ASSERT((ZeroFields ? SASigStructNewOOL_true : SASigStructNewOOL_false)
.failureMode == FailureMode::FailOnNullPtr);
JSContext* cx = instance->cx();
// The new struct will be allocated in an initial heap as determined by
// pretenuring logic as set up in `Instance::init`.
return WasmStructObject::createStructOOL<ZeroFields>(
cx, typeDefData, typeDefData->allocSite.initialHeap());
}
template void* Instance::structNewOOL<true>(Instance* instance,
TypeDefInstanceData* typeDefData);
template void* Instance::structNewOOL<false>(Instance* instance,
TypeDefInstanceData* typeDefData);
/* static */
template <bool ZeroFields>
void* Instance::arrayNew(Instance* instance, uint32_t numElements,
TypeDefInstanceData* typeDefData) {
MOZ_ASSERT(
(ZeroFields ? SASigArrayNew_true : SASigArrayNew_false).failureMode ==
FailureMode::FailOnNullPtr);
JSContext* cx = instance->cx();
// The new array will be allocated in an initial heap as determined by
// pretenuring logic as set up in `Instance::init`.
return WasmArrayObject::createArray<ZeroFields>(
cx, typeDefData, typeDefData->allocSite.initialHeap(), numElements);
}
template void* Instance::arrayNew<true>(Instance* instance,
uint32_t numElements,
TypeDefInstanceData* typeDefData);
template void* Instance::arrayNew<false>(Instance* instance,
uint32_t numElements,
TypeDefInstanceData* typeDefData);
// Copies from a data segment into a wasm GC array. Performs the necessary
// bounds checks, accounting for the array's element size. If this function
// returns false, it has already reported a trap error.
static bool ArrayCopyFromData(JSContext* cx, Handle<WasmArrayObject*> arrayObj,
const TypeDef* typeDef, uint32_t arrayIndex,
const DataSegment* seg, uint32_t segByteOffset,
uint32_t numElements) {
// Compute the number of bytes to copy, ensuring it's below 2^32.
CheckedUint32 numBytesToCopy =
CheckedUint32(numElements) *
CheckedUint32(typeDef->arrayType().elementType_.size());
if (!numBytesToCopy.isValid()) {
// Because the request implies that 2^32 or more bytes are to be copied.
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return false;
}
// Range-check the copy. The obvious thing to do is to compute the offset
// of the last byte to copy, but that would cause underflow in the
// zero-length-and-zero-offset case. Instead, compute that value plus one;
// in other words the offset of the first byte *not* to copy.
CheckedUint32 lastByteOffsetPlus1 =
CheckedUint32(segByteOffset) + numBytesToCopy;
CheckedUint32 numBytesAvailable(seg->bytes.length());
if (!lastByteOffsetPlus1.isValid() || !numBytesAvailable.isValid() ||
lastByteOffsetPlus1.value() > numBytesAvailable.value()) {
// Because the last byte to copy doesn't exist inside `seg->bytes`.
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return false;
}
// Range check the destination array.
uint64_t dstNumElements = uint64_t(arrayObj->numElements_);
if (uint64_t(arrayIndex) + uint64_t(numElements) > dstNumElements) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return false;
}
// Because `numBytesToCopy` is an in-range `CheckedUint32`, the cast to
// `size_t` is safe even on a 32-bit target.
if (numElements != 0) {
memcpy(arrayObj->data_, &seg->bytes[segByteOffset],
size_t(numBytesToCopy.value()));
}
return true;
}
// Copies from an element segment into a wasm GC array. Performs the necessary
// bounds checks, accounting for the array's element size. If this function
// returns false, it has already reported a trap error.
static bool ArrayCopyFromElem(JSContext* cx, Handle<WasmArrayObject*> arrayObj,
uint32_t arrayIndex,
const InstanceElemSegment& seg,
uint32_t segOffset, uint32_t numElements) {
// Range-check the copy. As in ArrayCopyFromData, compute the index of the
// last element to copy, plus one.
CheckedUint32 lastIndexPlus1 =
CheckedUint32(segOffset) + CheckedUint32(numElements);
CheckedUint32 numElemsAvailable(seg.length());
if (!lastIndexPlus1.isValid() || !numElemsAvailable.isValid() ||
lastIndexPlus1.value() > numElemsAvailable.value()) {
// Because the last element to copy doesn't exist inside the segment.
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return false;
}
// Range check the destination array.
uint64_t dstNumElements = uint64_t(arrayObj->numElements_);
if (uint64_t(arrayIndex) + uint64_t(numElements) > dstNumElements) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return false;
}
GCPtr<AnyRef>* dst = reinterpret_cast<GCPtr<AnyRef>*>(arrayObj->data_);
for (uint32_t i = 0; i < numElements; i++) {
dst[i] = seg[segOffset + i];
}
return true;
}
// Creates an array (WasmArrayObject) containing `numElements` of type
// described by `typeDef`. Initialises it with data copied from the data
// segment whose index is `segIndex`, starting at byte offset `segByteOffset`
// in the segment. Traps if the segment doesn't hold enough bytes to fill the
// array.
/* static */ void* Instance::arrayNewData(Instance* instance,
uint32_t segByteOffset,
uint32_t numElements,
TypeDefInstanceData* typeDefData,
uint32_t segIndex) {
MOZ_ASSERT(SASigArrayNewData.failureMode == FailureMode::FailOnNullPtr);
JSContext* cx = instance->cx();
// Check that the data segment is valid for use.
MOZ_RELEASE_ASSERT(size_t(segIndex) < instance->passiveDataSegments_.length(),
"ensured by validation");
const DataSegment* seg = instance->passiveDataSegments_[segIndex];
// `seg` will be nullptr if the segment has already been 'data.drop'ed
// (either implicitly in the case of 'active' segments during instantiation,
// or explicitly by the data.drop instruction.) In that case we can
// continue only if there's no need to copy any data out of it.
if (!seg && (numElements != 0 || segByteOffset != 0)) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return nullptr;
}
// At this point, if `seg` is null then `numElements` and `segByteOffset`
// are both zero.
const TypeDef* typeDef = typeDefData->typeDef;
Rooted<WasmArrayObject*> arrayObj(
cx,
WasmArrayObject::createArray<true>(
cx, typeDefData, typeDefData->allocSite.initialHeap(), numElements));
if (!arrayObj) {
// WasmArrayObject::createArray will have reported OOM.
return nullptr;
}
MOZ_RELEASE_ASSERT(arrayObj->is<WasmArrayObject>());
if (!seg) {
// A zero-length array was requested and has been created, so we're done.
return arrayObj;
}
if (!ArrayCopyFromData(cx, arrayObj, typeDef, 0, seg, segByteOffset,
numElements)) {
// Trap errors will be reported by ArrayCopyFromData.
return nullptr;
}
return arrayObj;
}
// This is almost identical to ::arrayNewData, apart from the final part that
// actually copies the data. It creates an array (WasmArrayObject)
// containing `numElements` of type described by `typeDef`. Initialises it
// with data copied from the element segment whose index is `segIndex`,
// starting at element number `srcOffset` in the segment. Traps if the
// segment doesn't hold enough elements to fill the array.
/* static */ void* Instance::arrayNewElem(Instance* instance,
uint32_t srcOffset,
uint32_t numElements,
TypeDefInstanceData* typeDefData,
uint32_t segIndex) {
MOZ_ASSERT(SASigArrayNewElem.failureMode == FailureMode::FailOnNullPtr);
JSContext* cx = instance->cx();
// Check that the element segment is valid for use.
MOZ_RELEASE_ASSERT(size_t(segIndex) < instance->passiveElemSegments_.length(),
"ensured by validation");
const InstanceElemSegment& seg = instance->passiveElemSegments_[segIndex];
const TypeDef* typeDef = typeDefData->typeDef;
// Any data coming from an element segment will be an AnyRef. Writes into
// array memory are done with raw pointers, so we must ensure here that the
// destination size is correct.
MOZ_RELEASE_ASSERT(typeDef->arrayType().elementType_.size() ==
sizeof(AnyRef));
Rooted<WasmArrayObject*> arrayObj(
cx,
WasmArrayObject::createArray<true>(
cx, typeDefData, typeDefData->allocSite.initialHeap(), numElements));
if (!arrayObj) {
// WasmArrayObject::createArray will have reported OOM.
return nullptr;
}
MOZ_RELEASE_ASSERT(arrayObj->is<WasmArrayObject>());
if (!ArrayCopyFromElem(cx, arrayObj, 0, seg, srcOffset, numElements)) {
// Trap errors will be reported by ArrayCopyFromElems.
return nullptr;
}
return arrayObj;
}
// Copies a range of the data segment `segIndex` into an array
// (WasmArrayObject), starting at offset `segByteOffset` in the data segment and
// index `index` in the array. `numElements` is the length of the copy in array
// elements, NOT bytes - the number of bytes will be computed based on the type
// of the array.
//
// Traps if accesses are out of bounds for either the data segment or the array,
// or if the array object is null.
/* static */ int32_t Instance::arrayInitData(
Instance* instance, void* array, uint32_t index, uint32_t segByteOffset,
uint32_t numElements, TypeDefInstanceData* typeDefData, uint32_t segIndex) {
MOZ_ASSERT(SASigArrayInitData.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
// Check that the data segment is valid for use.
MOZ_RELEASE_ASSERT(size_t(segIndex) < instance->passiveDataSegments_.length(),
"ensured by validation");
const DataSegment* seg = instance->passiveDataSegments_[segIndex];
// `seg` will be nullptr if the segment has already been 'data.drop'ed
// (either implicitly in the case of 'active' segments during instantiation,
// or explicitly by the data.drop instruction.) In that case we can
// continue only if there's no need to copy any data out of it.
if (!seg && (numElements != 0 || segByteOffset != 0)) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
// At this point, if `seg` is null then `numElements` and `segByteOffset`
// are both zero.
// Trap if the array is null.
if (!array) {
ReportTrapError(cx, JSMSG_WASM_DEREF_NULL);
return -1;
}
if (!seg) {
// A zero-length init was requested, so we're done.
return 0;
}
// Get hold of the array.
const TypeDef* typeDef = typeDefData->typeDef;
Rooted<WasmArrayObject*> arrayObj(cx, static_cast<WasmArrayObject*>(array));
MOZ_RELEASE_ASSERT(arrayObj->is<WasmArrayObject>());
if (!ArrayCopyFromData(cx, arrayObj, typeDef, index, seg, segByteOffset,
numElements)) {
// Trap errors will be reported by ArrayCopyFromData.
return -1;
}
return 0;
}
// Copies a range of the element segment `segIndex` into an array
// (WasmArrayObject), starting at offset `segOffset` in the elem segment and
// index `index` in the array. `numElements` is the length of the copy.
//
// Traps if accesses are out of bounds for either the elem segment or the array,
// or if the array object is null.
/* static */ int32_t Instance::arrayInitElem(Instance* instance, void* array,
uint32_t index, uint32_t segOffset,
uint32_t numElements,
TypeDefInstanceData* typeDefData,
uint32_t segIndex) {
MOZ_ASSERT(SASigArrayInitElem.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
// Check that the element segment is valid for use.
MOZ_RELEASE_ASSERT(size_t(segIndex) < instance->passiveElemSegments_.length(),
"ensured by validation");
const InstanceElemSegment& seg = instance->passiveElemSegments_[segIndex];
// Trap if the array is null.
if (!array) {
ReportTrapError(cx, JSMSG_WASM_DEREF_NULL);
return -1;
}
const TypeDef* typeDef = typeDefData->typeDef;
// Any data coming from an element segment will be an AnyRef. Writes into
// array memory are done with raw pointers, so we must ensure here that the
// destination size is correct.
MOZ_RELEASE_ASSERT(typeDef->arrayType().elementType_.size() ==
sizeof(AnyRef));
// Get hold of the array.
Rooted<WasmArrayObject*> arrayObj(cx, static_cast<WasmArrayObject*>(array));
MOZ_RELEASE_ASSERT(arrayObj->is<WasmArrayObject>());
if (!ArrayCopyFromElem(cx, arrayObj, index, seg, segOffset, numElements)) {
// Trap errors will be reported by ArrayCopyFromElems.
return -1;
}
return 0;
}
/* static */ int32_t Instance::arrayCopy(Instance* instance, void* dstArray,
uint32_t dstIndex, void* srcArray,
uint32_t srcIndex,
uint32_t numElements,
uint32_t elementSize) {
MOZ_ASSERT(SASigArrayCopy.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
// At the entry point, `elementSize` may be negative to indicate
// reftyped-ness of array elements. That is done in order to avoid having
// to pass yet another (boolean) parameter here.
// "traps if either array is null"
if (!srcArray || !dstArray) {
ReportTrapError(cx, JSMSG_WASM_DEREF_NULL);
return -1;
}
bool elemsAreRefTyped = false;
if (int32_t(elementSize) < 0) {
elemsAreRefTyped = true;
elementSize = uint32_t(-int32_t(elementSize));
}
MOZ_ASSERT(elementSize >= 1 && elementSize <= 16);
// Get hold of the two arrays.
Rooted<WasmArrayObject*> dstArrayObj(cx,
static_cast<WasmArrayObject*>(dstArray));
MOZ_RELEASE_ASSERT(dstArrayObj->is<WasmArrayObject>());
Rooted<WasmArrayObject*> srcArrayObj(cx,
static_cast<WasmArrayObject*>(srcArray));
MOZ_RELEASE_ASSERT(srcArrayObj->is<WasmArrayObject>());
// If WasmArrayObject::numElements() is changed to return 64 bits, the
// following checking logic will be incorrect.
STATIC_ASSERT_WASMARRAYELEMENTS_NUMELEMENTS_IS_U32;
// "traps if destination + length > len(array1)"
uint64_t dstNumElements = uint64_t(dstArrayObj->numElements_);
if (uint64_t(dstIndex) + uint64_t(numElements) > dstNumElements) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
// "traps if source + length > len(array2)"
uint64_t srcNumElements = uint64_t(srcArrayObj->numElements_);
if (uint64_t(srcIndex) + uint64_t(numElements) > srcNumElements) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
// trap if we're asked to copy 2^32 or more bytes on a 32-bit target.
uint64_t numBytesToCopy = uint64_t(numElements) * uint64_t(elementSize);
#ifndef JS_64BIT
if (numBytesToCopy > uint64_t(UINT32_MAX)) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
#endif
// We're now assured that `numBytesToCopy` can be cast to `size_t` without
// overflow.
// Actually do the copy, taking care to handle cases where the src and dst
// areas overlap.
uint8_t* srcBase = srcArrayObj->data_;
uint8_t* dstBase = dstArrayObj->data_;
srcBase += size_t(srcIndex) * size_t(elementSize);
dstBase += size_t(dstIndex) * size_t(elementSize);
if (numBytesToCopy == 0 || srcBase == dstBase) {
// Early exit if there's no work to do.
return 0;
}
if (!elemsAreRefTyped) {
// Hand off to memmove, which is presumably highly optimized.
memmove(dstBase, srcBase, size_t(numBytesToCopy));
return 0;
}
// We're copying refs; doing that needs suitable GC barrier-ing.
uint8_t* nextSrc;
uint8_t* nextDst;
intptr_t step;
if (dstBase < srcBase) {
// Moving data backwards in the address space; so iterate forwards through
// the array.
step = intptr_t(elementSize);
nextSrc = srcBase;
nextDst = dstBase;
} else {
// Moving data forwards; so iterate backwards.
step = -intptr_t(elementSize);
nextSrc = srcBase + size_t(numBytesToCopy) - size_t(elementSize);
nextDst = dstBase + size_t(numBytesToCopy) - size_t(elementSize);
}
// We don't know the type of the elems, only that they are refs. No matter,
// we can simply make up a type.
RefType aRefType = RefType::eq();
// Do the iteration
for (size_t i = 0; i < size_t(numElements); i++) {
// Copy `elementSize` bytes from `nextSrc` to `nextDst`.
RootedVal value(cx, aRefType);
value.get().readFromHeapLocation(nextSrc);
value.get().writeToHeapLocation(nextDst);
nextSrc += step;
nextDst += step;
}
return 0;
}
/* static */ void* Instance::exceptionNew(Instance* instance, void* tagArg) {
MOZ_ASSERT(SASigExceptionNew.failureMode == FailureMode::FailOnNullPtr);
JSContext* cx = instance->cx();
AnyRef tag = AnyRef::fromCompiledCode(tagArg);
Rooted<WasmTagObject*> tagObj(cx, &tag.toJSObject().as<WasmTagObject>());
RootedObject proto(cx, &cx->global()->getPrototype(JSProto_WasmException));
RootedObject stack(cx, nullptr);
// An OOM will result in null which will be caught on the wasm side.
return AnyRef::fromJSObjectOrNull(
WasmExceptionObject::create(cx, tagObj, stack, proto))
.forCompiledCode();
}
/* static */ int32_t Instance::throwException(Instance* instance,
void* exceptionArg) {
MOZ_ASSERT(SASigThrowException.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
AnyRef exception = AnyRef::fromCompiledCode(exceptionArg);
RootedValue exnVal(cx, exception.toJSValue());
cx->setPendingException(exnVal, nullptr);
// By always returning -1, we trigger a wasmTrap(Trap::ThrowReported),
// and use that to trigger the stack walking for this exception.
return -1;
}
/* static */ int32_t Instance::intrI8VecMul(Instance* instance, uint32_t dest,
uint32_t src1, uint32_t src2,
uint32_t len, uint8_t* memBase) {
MOZ_ASSERT(SASigIntrI8VecMul.failureMode == FailureMode::FailOnNegI32);
JSContext* cx = instance->cx();
const WasmArrayRawBuffer* rawBuf = WasmArrayRawBuffer::fromDataPtr(memBase);
size_t memLen = rawBuf->byteLength();
// Bounds check and deal with arithmetic overflow.
uint64_t destLimit = uint64_t(dest) + uint64_t(len);
uint64_t src1Limit = uint64_t(src1) + uint64_t(len);
uint64_t src2Limit = uint64_t(src2) + uint64_t(len);
if (destLimit > memLen || src1Limit > memLen || src2Limit > memLen) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
// Basic dot product
uint8_t* destPtr = &memBase[dest];
uint8_t* src1Ptr = &memBase[src1];
uint8_t* src2Ptr = &memBase[src2];
while (len > 0) {
*destPtr = (*src1Ptr) * (*src2Ptr);
destPtr++;
src1Ptr++;
src2Ptr++;
len--;
}
return 0;
}
// TODO: this cast is irregular and not representable in wasm, as it does not
// take into account the enclosing recursion group of the type. This is
// temporary until builtin module functions can specify a precise array type
// for params/results.
template <bool isMutable>
static WasmArrayObject* UncheckedCastToArrayI16(HandleAnyRef ref) {
JSObject& object = ref.toJSObject();
WasmArrayObject& array = object.as<WasmArrayObject>();
DebugOnly<const ArrayType*> type(&array.typeDef().arrayType());
MOZ_ASSERT(type->elementType_ == StorageType::I16);
MOZ_ASSERT(type->isMutable_ == isMutable);
return &array;
}
/* static */
int32_t Instance::stringTest(Instance* instance, void* stringArg) {
AnyRef string = AnyRef::fromCompiledCode(stringArg);
if (string.isNull() || !string.isJSString()) {
return 0;
}
return 1;
}
/* static */
void* Instance::stringCast(Instance* instance, void* stringArg) {
AnyRef string = AnyRef::fromCompiledCode(stringArg);
if (string.isNull() || !string.isJSString()) {
ReportTrapError(instance->cx(), JSMSG_WASM_BAD_CAST);
return nullptr;
}
return string.forCompiledCode();
}
/* static */
void* Instance::stringFromCharCodeArray(Instance* instance, void* arrayArg,
uint32_t arrayStart,
uint32_t arrayCount) {
JSContext* cx = instance->cx();
RootedAnyRef arrayRef(cx, AnyRef::fromCompiledCode(arrayArg));
Rooted<WasmArrayObject*> array(cx, UncheckedCastToArrayI16<true>(arrayRef));
CheckedUint32 lastIndexPlus1 =
CheckedUint32(arrayStart) + CheckedUint32(arrayCount);
if (!lastIndexPlus1.isValid() ||
lastIndexPlus1.value() > array->numElements_) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return nullptr;
}
// GC is disabled on this call since it can cause the array to move,
// invalidating the data pointer we pass as a parameter
JSLinearString* string = NewStringCopyN<NoGC, char16_t>(
cx, (char16_t*)array->data_ + arrayStart, arrayCount);
if (!string) {
return nullptr;
}
return AnyRef::fromJSString(string).forCompiledCode();
}
/* static */
int32_t Instance::stringIntoCharCodeArray(Instance* instance, void* stringArg,
void* arrayArg, uint32_t arrayStart) {
JSContext* cx = instance->cx();
AnyRef stringRef = AnyRef::fromCompiledCode(stringArg);
if (!stringRef.isJSString()) {
ReportTrapError(cx, JSMSG_WASM_BAD_CAST);
return -1;
}
Rooted<JSString*> string(cx, stringRef.toJSString());
size_t stringLength = string->length();
RootedAnyRef arrayRef(cx, AnyRef::fromCompiledCode(arrayArg));
Rooted<WasmArrayObject*> array(cx, UncheckedCastToArrayI16<true>(arrayRef));
CheckedUint32 lastIndexPlus1 = CheckedUint32(arrayStart) + stringLength;
if (!lastIndexPlus1.isValid() ||
lastIndexPlus1.value() > array->numElements_) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
JSLinearString* linearStr = string->ensureLinear(cx);
if (!linearStr) {
return -1;
}
char16_t* arrayData = reinterpret_cast<char16_t*>(array->data_);
CopyChars(arrayData + arrayStart, *linearStr);
return stringLength;
}
void* Instance::stringFromCharCode(Instance* instance, uint32_t charCode) {
JSContext* cx = instance->cx();
JSString* str = StringFromCharCode(cx, int32_t(charCode));
if (!str) {
MOZ_ASSERT(cx->isThrowingOutOfMemory());
return nullptr;
}
return AnyRef::fromJSString(str).forCompiledCode();
}
void* Instance::stringFromCodePoint(Instance* instance, uint32_t codePoint) {
JSContext* cx = instance->cx();
// Check for any error conditions before calling fromCodePoint so we report
// the correct error
if (codePoint > unicode::NonBMPMax) {
ReportTrapError(cx, JSMSG_WASM_BAD_CODEPOINT);
return nullptr;
}
JSString* str = StringFromCodePoint(cx, char32_t(codePoint));
if (!str) {
MOZ_ASSERT(cx->isThrowingOutOfMemory());
return nullptr;
}
return AnyRef::fromJSString(str).forCompiledCode();
}
int32_t Instance::stringCharCodeAt(Instance* instance, void* stringArg,
uint32_t index) {
JSContext* cx = instance->cx();
AnyRef stringRef = AnyRef::fromCompiledCode(stringArg);
if (!stringRef.isJSString()) {
ReportTrapError(cx, JSMSG_WASM_BAD_CAST);
return -1;
}
Rooted<JSString*> string(cx, stringRef.toJSString());
if (index >= string->length()) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
char16_t c;
if (!string->getChar(cx, index, &c)) {
MOZ_ASSERT(cx->isThrowingOutOfMemory());
return false;
}
return c;
}
int32_t Instance::stringCodePointAt(Instance* instance, void* stringArg,
uint32_t index) {
JSContext* cx = instance->cx();
AnyRef stringRef = AnyRef::fromCompiledCode(stringArg);
if (!stringRef.isJSString()) {
ReportTrapError(cx, JSMSG_WASM_BAD_CAST);
return -1;
}
Rooted<JSString*> string(cx, stringRef.toJSString());
if (index >= string->length()) {
ReportTrapError(cx, JSMSG_WASM_OUT_OF_BOUNDS);
return -1;
}
char32_t c;
if (!string->getCodePoint(cx, index, &c)) {
MOZ_ASSERT(cx->isThrowingOutOfMemory());
return false;
}
return c;
}
int32_t Instance::stringLength(Instance* instance, void* stringArg) {
JSContext* cx = instance->cx();
AnyRef stringRef = AnyRef::fromCompiledCode(stringArg);
if (!stringRef.isJSString()) {
ReportTrapError(cx, JSMSG_WASM_BAD_CAST);
return -1;
}
static_assert(JS::MaxStringLength <= INT32_MAX);
return (int32_t)stringRef.toJSString()->length();
}
void* Instance::stringConcat(Instance* instance, void* firstStringArg,
void* secondStringArg) {
JSContext* cx = instance->cx();
AnyRef firstStringRef = AnyRef::fromCompiledCode(firstStringArg);
AnyRef secondStringRef = AnyRef::fromCompiledCode(secondStringArg);
if (!firstStringRef.isJSString() || !secondStringRef.isJSString()) {
ReportTrapError(cx, JSMSG_WASM_BAD_CAST);
return nullptr;
}
Rooted<JSString*> firstString(cx, firstStringRef.toJSString());
Rooted<JSString*> secondString(cx, secondStringRef.toJSString());
JSString* result = ConcatStrings<CanGC>(cx, firstString, secondString);
if (!result) {
MOZ_ASSERT(cx->isThrowingOutOfMemory());
return nullptr;
}
return AnyRef::fromJSString(result).forCompiledCode();
}
void* Instance::stringSubstring(Instance* instance, void* stringArg,
int32_t startIndex, int32_t endIndex) {
JSContext* cx = instance->cx();
AnyRef stringRef = AnyRef::fromCompiledCode(stringArg);
if (!stringRef.isJSString()) {
ReportTrapError(cx, JSMSG_WASM_BAD_CAST);
return nullptr;
}
RootedString string(cx, stringRef.toJSString());
static_assert(JS::MaxStringLength <= INT32_MAX);
if ((uint32_t)startIndex > string->length() ||
(uint32_t)endIndex > string->length() || startIndex > endIndex) {
return AnyRef::fromJSString(cx->names().empty_).forCompiledCode();
}
JSString* result =
SubstringKernel(cx, string, startIndex, endIndex - startIndex);
if (!result) {
MOZ_ASSERT(cx->isThrowingOutOfMemory());
return nullptr;
}
return AnyRef::fromJSString(result).forCompiledCode();
}
int32_t Instance::stringEquals(Instance* instance, void* firstStringArg,
void* secondStringArg) {
JSContext* cx = instance->cx();
AnyRef firstStringRef = AnyRef::fromCompiledCode(firstStringArg);
AnyRef secondStringRef = AnyRef::fromCompiledCode(secondStringArg);
if (!firstStringRef.isJSString() || !secondStringRef.isJSString()) {
ReportTrapError(cx, JSMSG_WASM_BAD_CAST);
return -1;
}
bool equals;
if (!EqualStrings(cx, firstStringRef.toJSString(),
secondStringRef.toJSString(), &equals)) {
MOZ_ASSERT(cx->isThrowingOutOfMemory());
return -1;
}
return equals ? 1 : 0;
}
int32_t Instance::stringCompare(Instance* instance, void* firstStringArg,
void* secondStringArg) {
JSContext* cx = instance->cx();
AnyRef firstStringRef = AnyRef::fromCompiledCode(firstStringArg);
AnyRef secondStringRef = AnyRef::fromCompiledCode(secondStringArg);
if (!firstStringRef.isJSString() || !secondStringRef.isJSString()) {
ReportTrapError(cx, JSMSG_WASM_BAD_CAST);
return INT32_MAX;
}
int32_t result;
if (!CompareStrings(cx, firstStringRef.toJSString(),
secondStringRef.toJSString(), &result)) {
MOZ_ASSERT(cx->isThrowingOutOfMemory());
return INT32_MAX;
}
if (result < 0) {
return -1;
}
if (result > 0) {
return 1;
}
return result;
}
//////////////////////////////////////////////////////////////////////////////
//
// Instance creation and related.
Instance::Instance(JSContext* cx, Handle<WasmInstanceObject*> object,
const SharedCode& code, SharedTableVector&& tables,
UniqueDebugState maybeDebug)
: realm_(cx->realm()),
jsJitArgsRectifier_(
cx->runtime()->jitRuntime()->getArgumentsRectifier().value),
jsJitExceptionHandler_(
cx->runtime()->jitRuntime()->getExceptionTail().value),
preBarrierCode_(
cx->runtime()->jitRuntime()->preBarrier(MIRType::WasmAnyRef).value),
storeBuffer_(&cx->runtime()->gc.storeBuffer()),
object_(object),
code_(std::move(code)),
tables_(std::move(tables)),
maybeDebug_(std::move(maybeDebug)),
debugFilter_(nullptr),
maxInitializedGlobalsIndexPlus1_(0) {
for (size_t i = 0; i < N_BASELINE_SCRATCH_WORDS; i++) {
baselineScratchWords_[i] = 0;
}
}
Instance* Instance::create(JSContext* cx, Handle<WasmInstanceObject*> object,
const SharedCode& code, uint32_t instanceDataLength,
SharedTableVector&& tables,
UniqueDebugState maybeDebug) {
void* base = js_calloc(alignof(Instance) + offsetof(Instance, data_) +
instanceDataLength);
if (!base) {
ReportOutOfMemory(cx);
return nullptr;
}
void* aligned = (void*)AlignBytes(uintptr_t(base), alignof(Instance));
auto* instance = new (aligned)
Instance(cx, object, code, std::move(tables), std::move(maybeDebug));
instance->allocatedBase_ = base;
return instance;
}
void Instance::destroy(Instance* instance) {
instance->~Instance();
js_free(instance->allocatedBase_);
}
bool Instance::init(JSContext* cx, const JSObjectVector& funcImports,
const ValVector& globalImportValues,
Handle<WasmMemoryObjectVector> memories,
const WasmGlobalObjectVector& globalObjs,
const WasmTagObjectVector& tagObjs,
const DataSegmentVector& dataSegments,
const ModuleElemSegmentVector& elemSegments) {
MOZ_ASSERT(!!maybeDebug_ == metadata().debugEnabled);
#ifdef DEBUG
for (auto t : code_->tiers()) {
MOZ_ASSERT(funcImports.length() == metadata(t).funcImports.length());
}
#endif
MOZ_ASSERT(tables_.length() == metadata().tables.length());
cx_ = cx;
valueBoxClass_ = AnyRef::valueBoxClass();
resetInterrupt(cx);
jumpTable_ = code_->tieringJumpTable();
debugFilter_ = nullptr;
addressOfNeedsIncrementalBarrier_ =
cx->compartment()->zone()->addressOfNeedsIncrementalBarrier();
addressOfNurseryPosition_ = cx->nursery().addressOfPosition();
#ifdef JS_GC_ZEAL
addressOfGCZealModeBits_ = cx->runtime()->gc.addressOfZealModeBits();
#endif
// Initialize type definitions in the instance data.
const SharedTypeContext& types = metadata().types;
Zone* zone = realm()->zone();
for (uint32_t typeIndex = 0; typeIndex < types->length(); typeIndex++) {
const TypeDef& typeDef = types->type(typeIndex);
TypeDefInstanceData* typeDefData = typeDefInstanceData(typeIndex);
// Set default field values.
new (typeDefData) TypeDefInstanceData();
// Store the runtime type for this type index
typeDefData->typeDef = &typeDef;
typeDefData->superTypeVector = typeDef.superTypeVector();
if (typeDef.kind() == TypeDefKind::Struct ||
typeDef.kind() == TypeDefKind::Array) {
// Compute the parameters that allocation will use. First, the class
// and alloc kind for the type definition.
const JSClass* clasp;
gc::AllocKind allocKind;
if (typeDef.kind() == TypeDefKind::Struct) {
clasp = WasmStructObject::classForTypeDef(&typeDef);
allocKind = WasmStructObject::allocKindForTypeDef(&typeDef);
// Move the alloc kind to background if possible
if (CanChangeToBackgroundAllocKind(allocKind, clasp)) {
allocKind = ForegroundToBackgroundAllocKind(allocKind);
}
} else {
clasp = &WasmArrayObject::class_;
allocKind = gc::AllocKind::INVALID;
}
// Find the shape using the class and recursion group
const ObjectFlags objectFlags = {ObjectFlag::NotExtensible};
typeDefData->shape =
WasmGCShape::getShape(cx, clasp, cx->realm(), TaggedProto(),
&typeDef.recGroup(), objectFlags);
if (!typeDefData->shape) {
return false;
}
typeDefData->clasp = clasp;
typeDefData->allocKind = allocKind;
// Initialize the allocation site for pre-tenuring.
typeDefData->allocSite.initWasm(zone);
// If `typeDef` is a struct, cache its size here, so that allocators
// don't have to chase back through `typeDef` to determine that.
// Similarly, if `typeDef` is an array, cache its array element size
// here.
MOZ_ASSERT(typeDefData->unused == 0);
if (typeDef.kind() == TypeDefKind::Struct) {
typeDefData->structTypeSize = typeDef.structType().size_;
// StructLayout::close ensures this is an integral number of words.
MOZ_ASSERT((typeDefData->structTypeSize % sizeof(uintptr_t)) == 0);
} else {
uint32_t arrayElemSize = typeDef.arrayType().elementType_.size();
typeDefData->arrayElemSize = arrayElemSize;
MOZ_ASSERT(arrayElemSize == 16 || arrayElemSize == 8 ||
arrayElemSize == 4 || arrayElemSize == 2 ||
arrayElemSize == 1);
}
} else if (typeDef.kind() == TypeDefKind::Func) {
// Nothing to do; the default values are OK.
} else {
MOZ_ASSERT(typeDef.kind() == TypeDefKind::None);
MOZ_CRASH();
}
}
// Initialize function imports in the instance data
Tier callerTier = code_->bestTier();
for (size_t i = 0; i < metadata(callerTier).funcImports.length(); i++) {
JSObject* f = funcImports[i];
#ifdef ENABLE_WASM_JSPI
if (JSObject* suspendingObject = MaybeUnwrapSuspendingObject(f)) {
// Compile suspending function Wasm wrapper.
const FuncImport& fi = metadata(callerTier).funcImports[i];
const FuncType& funcType = metadata().getFuncImportType(fi);
RootedObject wrapped(cx, suspendingObject);
RootedFunction wrapper(
cx, WasmSuspendingFunctionCreate(cx, wrapped, funcType));
if (!wrapper) {
return false;
}
MOZ_ASSERT(IsWasmExportedFunction(wrapper));
f = wrapper;
}
#endif
MOZ_ASSERT(f->isCallable());
const FuncImport& fi = metadata(callerTier).funcImports[i];
const FuncType& funcType = metadata().getFuncImportType(fi);
FuncImportInstanceData& import = funcImportInstanceData(fi);
import.callable = f;
if (f->is<JSFunction>()) {
JSFunction* fun = &f->as<JSFunction>();
if (!isAsmJS() && IsWasmExportedFunction(fun)) {
WasmInstanceObject* calleeInstanceObj =
ExportedFunctionToInstanceObject(fun);
Instance& calleeInstance = calleeInstanceObj->instance();
Tier calleeTier = calleeInstance.code().bestTier();
const CodeRange& codeRange =
calleeInstanceObj->getExportedFunctionCodeRange(
&f->as<JSFunction>(), calleeTier);
import.instance = &calleeInstance;
import.realm = fun->realm();
import.code = calleeInstance.codeBase(calleeTier) +
codeRange.funcUncheckedCallEntry();
} else if (void* thunk = MaybeGetBuiltinThunk(fun, funcType)) {
import.instance = this;
import.realm = fun->realm();
import.code = thunk;
} else {
import.instance = this;
import.realm = fun->realm();
import.code = codeBase(callerTier) + fi.interpExitCodeOffset();
}
} else {
import.instance = this;
import.realm = f->nonCCWRealm();
import.code = codeBase(callerTier) + fi.interpExitCodeOffset();
}
}
// Initialize globals in the instance data.
//
// This must be performed after we have initialized runtime types as a global
// initializer may reference them.
//
// We increment `maxInitializedGlobalsIndexPlus1_` every iteration of the
// loop, as we call out to `InitExpr::evaluate` which may call
// `constantGlobalGet` which uses this value to assert we're never accessing
// uninitialized globals.
maxInitializedGlobalsIndexPlus1_ = 0;
for (size_t i = 0; i < metadata().globals.length();
i++, maxInitializedGlobalsIndexPlus1_ = i) {
const GlobalDesc& global = metadata().globals[i];
// Constants are baked into the code, never stored in the global area.
if (global.isConstant()) {
continue;
}
uint8_t* globalAddr = data() + global.offset();
switch (global.kind()) {
case GlobalKind::Import: {
size_t imported = global.importIndex();
if (global.isIndirect()) {
*(void**)globalAddr =
(void*)&globalObjs[imported]->val().get().cell();
} else {
globalImportValues[imported].writeToHeapLocation(globalAddr);
}
break;
}
case GlobalKind::Variable: {
RootedVal val(cx);
const InitExpr& init = global.initExpr();
Rooted<WasmInstanceObject*> instanceObj(cx, object());
if (!init.evaluate(cx, instanceObj, &val)) {
return false;
}
if (global.isIndirect()) {
// Initialize the cell
globalObjs[i]->setVal(val);
// Link to the cell
*(void**)globalAddr = globalObjs[i]->addressOfCell();
} else {
val.get().writeToHeapLocation(globalAddr);
}
break;
}
case GlobalKind::Constant: {
MOZ_CRASH("skipped at the top");
}
}
}
// All globals were initialized
MOZ_ASSERT(maxInitializedGlobalsIndexPlus1_ == metadata().globals.length());
// Initialize memories in the instance data
for (size_t i = 0; i < memories.length(); i++) {
const MemoryDesc& md = metadata().memories[i];
MemoryInstanceData& data = memoryInstanceData(i);
WasmMemoryObject* memory = memories.get()[i];
data.memory = memory;
data.base = memory->buffer().dataPointerEither().unwrap();
size_t limit = memory->boundsCheckLimit();
#if !defined(JS_64BIT)
// We assume that the limit is a 32-bit quantity
MOZ_ASSERT(limit <= UINT32_MAX);
#endif
data.boundsCheckLimit = limit;
data.isShared = md.isShared();
// Add observer if our memory base may grow
if (memory && memory->movingGrowable() &&
!memory->addMovingGrowObserver(cx, object_)) {
return false;
}
}
// Cache the default memory's values
if (memories.length() > 0) {
MemoryInstanceData& data = memoryInstanceData(0);
memory0Base_ = data.base;
memory0BoundsCheckLimit_ = data.boundsCheckLimit;
} else {
memory0Base_ = nullptr;
memory0BoundsCheckLimit_ = 0;
}
// Initialize tables in the instance data
for (size_t i = 0; i < tables_.length(); i++) {
const TableDesc& td = metadata().tables[i];
TableInstanceData& table = tableInstanceData(i);
table.length = tables_[i]->length();
table.elements = tables_[i]->instanceElements();
// Non-imported tables, with init_expr, has to be initialized with
// the evaluated value.
if (!td.isImported && td.initExpr) {
Rooted<WasmInstanceObject*> instanceObj(cx, object());
RootedVal val(cx);
if (!td.initExpr->evaluate(cx, instanceObj, &val)) {
return false;
}
RootedAnyRef ref(cx, val.get().ref());
tables_[i]->fillUninitialized(0, tables_[i]->length(), ref, cx);
}
}
#ifdef DEBUG
// All (linked) tables with non-nullable types must be initialized.
for (size_t i = 0; i < tables_.length(); i++) {
const TableDesc& td = metadata().tables[i];
if (!td.elemType.isNullable()) {
tables_[i]->assertRangeNotNull(0, tables_[i]->length());
}
}
#endif // DEBUG
// Initialize tags in the instance data
for (size_t i = 0; i < metadata().tags.length(); i++) {
MOZ_ASSERT(tagObjs[i] != nullptr);
tagInstanceData(i).object = tagObjs[i];
}
pendingException_ = nullptr;
pendingExceptionTag_ = nullptr;
// Add debug filtering table.
if (metadata().debugEnabled) {
size_t numFuncs = metadata().debugNumFuncs();
size_t numWords = std::max<size_t>((numFuncs + 31) / 32, 1);
debugFilter_ = (uint32_t*)js_calloc(numWords, sizeof(uint32_t));
if (!debugFilter_) {
ReportOutOfMemory(cx);
return false;
}
}
// Add observers if our tables may grow
for (const SharedTable& table : tables_) {
if (table->movingGrowable() && !table->addMovingGrowObserver(cx, object_)) {
return false;
}
}
// Take references to the passive data segments
if (!passiveDataSegments_.resize(dataSegments.length())) {
ReportOutOfMemory(cx);
return false;
}
for (size_t i = 0; i < dataSegments.length(); i++) {
if (!dataSegments[i]->active()) {
passiveDataSegments_[i] = dataSegments[i];
}
}
// Create InstanceElemSegments for any passive element segments, since these
// are the ones available at runtime.
if (!passiveElemSegments_.resize(elemSegments.length())) {
ReportOutOfMemory(cx);
return false;
}
for (size_t i = 0; i < elemSegments.length(); i++) {
const ModuleElemSegment& seg = elemSegments[i];
if (seg.kind == ModuleElemSegment::Kind::Passive) {
passiveElemSegments_[i] = InstanceElemSegment();
InstanceElemSegment& instanceSeg = passiveElemSegments_[i];
if (!instanceSeg.reserve(seg.numElements())) {
ReportOutOfMemory(cx);
return false;
}
bool ok = iterElemsAnyrefs(seg, [&](uint32_t _, AnyRef ref) -> bool {
instanceSeg.infallibleAppend(ref);
return true;
});
if (!ok) {
return false;
}
}
}
return true;
}
Instance::~Instance() {
realm_->wasm.unregisterInstance(*this);
if (debugFilter_) {
js_free(debugFilter_);
}
// Any pending exceptions should have been consumed.
MOZ_ASSERT(pendingException_.isNull());
}
void Instance::setInterrupt() {
interrupt_ = true;
stackLimit_ = JS::NativeStackLimitMin;
}
bool Instance::isInterrupted() const {
return interrupt_ || stackLimit_ == JS::NativeStackLimitMin;
}
void Instance::resetInterrupt(JSContext* cx) {
interrupt_ = false;
#ifdef ENABLE_WASM_JSPI
if (cx->wasm().suspendableStackLimit != JS::NativeStackLimitMin) {
stackLimit_ = cx->wasm().suspendableStackLimit;
return;
}
#endif
stackLimit_ = cx->stackLimitForJitCode(JS::StackForUntrustedScript);
}
void Instance::setTemporaryStackLimit(JS::NativeStackLimit limit) {
if (!isInterrupted()) {
stackLimit_ = limit;
}
}
void Instance::resetTemporaryStackLimit(JSContext* cx) {
if (!isInterrupted()) {
stackLimit_ = cx->stackLimitForJitCode(JS::StackForUntrustedScript);
}
}
bool Instance::debugFilter(uint32_t funcIndex) const {
return (debugFilter_[funcIndex / 32] >> funcIndex % 32) & 1;
}
void Instance::setDebugFilter(uint32_t funcIndex, bool value) {
if (value) {
debugFilter_[funcIndex / 32] |= (1 << funcIndex % 32);
} else {
debugFilter_[funcIndex / 32] &= ~(1 << funcIndex % 32);
}
}
bool Instance::memoryAccessInGuardRegion(const uint8_t* addr,
unsigned numBytes) const {
MOZ_ASSERT(numBytes > 0);
for (uint32_t memoryIndex = 0; memoryIndex < metadata().memories.length();
memoryIndex++) {
uint8_t* base = memoryBase(memoryIndex).unwrap(/* comparison */);
if (addr < base) {
continue;
}
WasmMemoryObject* mem = memory(memoryIndex);
size_t lastByteOffset = addr - base + (numBytes - 1);
if (lastByteOffset >= mem->volatileMemoryLength() &&
lastByteOffset < mem->buffer().wasmMappedSize()) {
return true;
}
}
return false;
}
void Instance::tracePrivate(JSTracer* trc) {
// This method is only called from WasmInstanceObject so the only reason why
// TraceEdge is called is so that the pointer can be updated during a moving
// GC.
MOZ_ASSERT_IF(trc->isMarkingTracer(), gc::IsMarked(trc->runtime(), object_));
TraceEdge(trc, &object_, "wasm instance object");
// OK to just do one tier here; though the tiers have different funcImports
// tables, they share the instance object.
for (const FuncImport& fi : metadata(code().stableTier()).funcImports) {
TraceNullableEdge(trc, &funcImportInstanceData(fi).callable, "wasm import");
}
for (uint32_t memoryIndex = 0;
memoryIndex < code().metadata().memories.length(); memoryIndex++) {
MemoryInstanceData& memoryData = memoryInstanceData(memoryIndex);
TraceNullableEdge(trc, &memoryData.memory, "wasm memory object");
}
for (const SharedTable& table : tables_) {
table->trace(trc);
}
for (const GlobalDesc& global : code().metadata().globals) {
// Indirect reference globals get traced by the owning WebAssembly.Global.
if (!global.type().isRefRepr() || global.isConstant() ||
global.isIndirect()) {
continue;
}
GCPtr<AnyRef>* obj = (GCPtr<AnyRef>*)(data() + global.offset());
TraceNullableEdge(trc, obj, "wasm reference-typed global");
}
for (uint32_t tagIndex = 0; tagIndex < code().metadata().tags.length();
tagIndex++) {
TraceNullableEdge(trc, &tagInstanceData(tagIndex).object, "wasm tag");
}
const SharedTypeContext& types = metadata().types;
for (uint32_t typeIndex = 0; typeIndex < types->length(); typeIndex++) {
TypeDefInstanceData* typeDefData = typeDefInstanceData(typeIndex);
TraceNullableEdge(trc, &typeDefData->shape, "wasm shape");
}
TraceNullableEdge(trc, &pendingException_, "wasm pending exception value");
TraceNullableEdge(trc, &pendingExceptionTag_, "wasm pending exception tag");
passiveElemSegments_.trace(trc);
if (maybeDebug_) {
maybeDebug_->trace(trc);
}
}
void js::wasm::TraceInstanceEdge(JSTracer* trc, Instance* instance,
const char* name) {
if (IsTracerKind(trc, JS::TracerKind::Moving)) {
// Compacting GC: The Instance does not move so there is nothing to do here.
// Reading the object from the instance below would be a data race during
// multi-threaded updates. Compacting GC does not rely on graph traversal
// to find all edges that need to be updated.
return;
}
// Instance fields are traced by the owning WasmInstanceObject's trace
// hook. Tracing this ensures they are traced once.
JSObject* object = instance->objectUnbarriered();
TraceManuallyBarrieredEdge(trc, &object, name);
}
static uintptr_t* GetFrameScanStartForStackMap(
const Frame* frame, const StackMap* map,
uintptr_t* highestByteVisitedInPrevFrame) {
// |frame| points somewhere in the middle of the area described by |map|.
// We have to calculate |scanStart|, the lowest address that is described by
// |map|, by consulting |map->frameOffsetFromTop|.
const size_t numMappedBytes = map->header.numMappedWords * sizeof(void*);
const uintptr_t scanStart = uintptr_t(frame) +
(map->header.frameOffsetFromTop * sizeof(void*)) -
numMappedBytes;
MOZ_ASSERT(0 == scanStart % sizeof(void*));
// Do what we can to assert that, for consecutive wasm frames, their stack
// maps also abut exactly. This is a useful sanity check on the sizing of
// stackmaps.
//
// In debug builds, the stackmap construction machinery goes to considerable
// efforts to ensure that the stackmaps for consecutive frames abut exactly.
// This is so as to ensure there are no areas of stack inadvertently ignored
// by a stackmap, nor covered by two stackmaps. Hence any failure of this
// assertion is serious and should be investigated.
#ifndef JS_CODEGEN_ARM64
MOZ_ASSERT_IF(
highestByteVisitedInPrevFrame && *highestByteVisitedInPrevFrame != 0,
*highestByteVisitedInPrevFrame + 1 == scanStart);
#endif
if (highestByteVisitedInPrevFrame) {
*highestByteVisitedInPrevFrame = scanStart + numMappedBytes - 1;
}
// If we have some exit stub words, this means the map also covers an area
// created by a exit stub, and so the highest word of that should be a
// constant created by (code created by) GenerateTrapExit.
MOZ_ASSERT_IF(map->header.numExitStubWords > 0,
((uintptr_t*)scanStart)[map->header.numExitStubWords - 1 -
TrapExitDummyValueOffsetFromTop] ==
TrapExitDummyValue);
return (uintptr_t*)scanStart;
}
uintptr_t Instance::traceFrame(JSTracer* trc, const wasm::WasmFrameIter& wfi,
uint8_t* nextPC,
uintptr_t highestByteVisitedInPrevFrame) {
const StackMap* map = code().lookupStackMap(nextPC);
if (!map) {
return 0;
}
Frame* frame = wfi.frame();
uintptr_t* stackWords =
GetFrameScanStartForStackMap(frame, map, &highestByteVisitedInPrevFrame);
// Hand refs off to the GC.
for (uint32_t i = 0; i < map->header.numMappedWords; i++) {
if (map->get(i) != StackMap::Kind::AnyRef) {
continue;
}
TraceNullableRoot(trc, (AnyRef*)&stackWords[i],
"Instance::traceWasmFrame: normal word");
}
// Deal with any GC-managed fields in the DebugFrame, if it is
// present and those fields may be live.
if (map->header.hasDebugFrameWithLiveRefs) {
DebugFrame* debugFrame = DebugFrame::from(frame);
char* debugFrameP = (char*)debugFrame;
for (size_t i = 0; i < MaxRegisterResults; i++) {
if (debugFrame->hasSpilledRegisterRefResult(i)) {
char* resultRefP = debugFrameP + DebugFrame::offsetOfRegisterResult(i);
TraceNullableRoot(
trc, (AnyRef*)resultRefP,
"Instance::traceWasmFrame: DebugFrame::resultResults_");
}
}
if (debugFrame->hasCachedReturnJSValue()) {
char* cachedReturnJSValueP =
debugFrameP + DebugFrame::offsetOfCachedReturnJSValue();
TraceRoot(trc, (js::Value*)cachedReturnJSValueP,
"Instance::traceWasmFrame: DebugFrame::cachedReturnJSValue_");
}
}
return highestByteVisitedInPrevFrame;
}
void Instance::updateFrameForMovingGC(const wasm::WasmFrameIter& wfi,
uint8_t* nextPC) {
const StackMap* map = code().lookupStackMap(nextPC);
if (!map) {
return;
}
Frame* frame = wfi.frame();
uintptr_t* stackWords = GetFrameScanStartForStackMap(frame, map, nullptr);
// Update interior array data pointers for any inline-storage arrays that
// moved.
for (uint32_t i = 0; i < map->header.numMappedWords; i++) {
if (map->get(i) != StackMap::Kind::ArrayDataPointer) {
continue;
}
uint8_t** addressOfArrayDataPointer = (uint8_t**)&stackWords[i];
if (WasmArrayObject::isDataInline(*addressOfArrayDataPointer)) {
WasmArrayObject* oldArray =
WasmArrayObject::fromInlineDataPointer(*addressOfArrayDataPointer);
WasmArrayObject* newArray =
(WasmArrayObject*)gc::MaybeForwarded(oldArray);
*addressOfArrayDataPointer =
WasmArrayObject::addressOfInlineData(newArray);
}
}
}
WasmMemoryObject* Instance::memory(uint32_t memoryIndex) const {
return memoryInstanceData(memoryIndex).memory;
}
SharedMem<uint8_t*> Instance::memoryBase(uint32_t memoryIndex) const {
MOZ_ASSERT_IF(
memoryIndex == 0,
memory0Base_ == memory(memoryIndex)->buffer().dataPointerEither());
return memory(memoryIndex)->buffer().dataPointerEither();
}
SharedArrayRawBuffer* Instance::sharedMemoryBuffer(uint32_t memoryIndex) const {
MOZ_ASSERT(memory(memoryIndex)->isShared());
return memory(memoryIndex)->sharedArrayRawBuffer();
}
WasmInstanceObject* Instance::objectUnbarriered() const {
return object_.unbarrieredGet();
}
WasmInstanceObject* Instance::object() const { return object_; }
static bool EnsureEntryStubs(const Instance& instance, uint32_t funcIndex,
const FuncExport** funcExport,
void** interpEntry) {
Tier tier = instance.code().bestTier();
size_t funcExportIndex;
*funcExport =
&instance.metadata(tier).lookupFuncExport(funcIndex, &funcExportIndex);
const FuncExport& fe = **funcExport;
if (fe.hasEagerStubs()) {
*interpEntry = instance.codeBase(tier) + fe.eagerInterpEntryOffset();
return true;
}
MOZ_ASSERT(!instance.isAsmJS(), "only wasm can lazily export functions");
// If the best tier is Ion, life is simple: background compilation has
// already completed and has been committed, so there's no risk of race
// conditions here.
//
// If the best tier is Baseline, there could be a background compilation
// happening at the same time. The background compilation will lock the
// first tier lazy stubs first to stop new baseline stubs from being
// generated, then the second tier stubs to generate them.
//
// - either we take the tier1 lazy stub lock before the background
// compilation gets it, then we generate the lazy stub for tier1. When the
// background thread gets the tier1 lazy stub lock, it will see it has a
// lazy stub and will recompile it for tier2.
// - or we don't take the lock here first. Background compilation won't
// find a lazy stub for this function, thus won't generate it. So we'll do
// it ourselves after taking the tier2 lock.
//
// Also see doc block for stubs in WasmJS.cpp.
auto stubs = instance.code(tier).lazyStubs().writeLock();
*interpEntry = stubs->lookupInterpEntry(fe.funcIndex());
if (*interpEntry) {
return true;
}
// The best tier might have changed after we've taken the lock.
Tier prevTier = tier;
tier = instance.code().bestTier();
const Metadata& metadata = instance.metadata();
const CodeTier& codeTier = instance.code(tier);
if (tier == prevTier) {
if (!stubs->createOneEntryStub(funcExportIndex, metadata, codeTier)) {
return false;
}
*interpEntry = stubs->lookupInterpEntry(fe.funcIndex());
MOZ_ASSERT(*interpEntry);
return true;
}
MOZ_RELEASE_ASSERT(prevTier == Tier::Baseline && tier == Tier::Optimized);
auto stubs2 = instance.code(tier).lazyStubs().writeLock();
// If it didn't have a stub in the first tier, background compilation
// shouldn't have made one in the second tier.
MOZ_ASSERT(!stubs2->hasEntryStub(fe.funcIndex()));
if (!stubs2->createOneEntryStub(funcExportIndex, metadata, codeTier)) {
return false;
}
*interpEntry = stubs2->lookupInterpEntry(fe.funcIndex());
MOZ_ASSERT(*interpEntry);
return true;
}
static bool GetInterpEntryAndEnsureStubs(JSContext* cx, Instance& instance,
uint32_t funcIndex,
const CallArgs& args,
void** interpEntry,
const FuncType** funcType) {
const FuncExport* funcExport;
if (!EnsureEntryStubs(instance, funcIndex, &funcExport, interpEntry)) {
return false;
}
*funcType = &instance.metadata().getFuncExportType(*funcExport);
#ifdef DEBUG
// EnsureEntryStubs() has ensured proper jit-entry stubs have been created and
// installed in funcIndex's JumpTable entry, so check against the presence of
// the provisional lazy stub. See also
// WasmInstanceObject::getExportedFunction().
if (!funcExport->hasEagerStubs() && (*funcType)->canHaveJitEntry()) {
if (!EnsureBuiltinThunksInitialized()) {
return false;
}
JSFunction& callee = args.callee().as<JSFunction>();
void* provisionalLazyJitEntryStub = ProvisionalLazyJitEntryStub();
MOZ_ASSERT(provisionalLazyJitEntryStub);
MOZ_ASSERT(callee.isWasmWithJitEntry());
MOZ_ASSERT(*callee.wasmJitEntry() != provisionalLazyJitEntryStub);
}
#endif
return true;
}
bool wasm::ResultsToJSValue(JSContext* cx, ResultType type,
void* registerResultLoc,
Maybe<char*> stackResultsLoc,
MutableHandleValue rval, CoercionLevel level) {
if (type.empty()) {
// No results: set to undefined, and we're done.
rval.setUndefined();
return true;
}
// If we added support for multiple register results, we'd need to establish a
// convention for how to store them to memory in registerResultLoc. For now
// we can punt.
static_assert(MaxRegisterResults == 1);
// Stack results written to stackResultsLoc; register result written
// to registerResultLoc.
// First, convert the register return value, and prepare to iterate in
// push order. Note that if the register result is a reference type,
// it may be unrooted, so ToJSValue_anyref must not GC in that case.
ABIResultIter iter(type);
DebugOnly<bool> usedRegisterResult = false;
for (; !iter.done(); iter.next()) {
if (iter.cur().inRegister()) {
MOZ_ASSERT(!usedRegisterResult);
if (!ToJSValue<DebugCodegenVal>(cx, registerResultLoc, iter.cur().type(),
rval, level)) {
return false;
}
usedRegisterResult = true;
}
}
MOZ_ASSERT(usedRegisterResult);
MOZ_ASSERT((stackResultsLoc.isSome()) == (iter.count() > 1));
if (!stackResultsLoc) {
// A single result: we're done.
return true;
}
// Otherwise, collect results in an array, in push order.
Rooted<ArrayObject*> array(cx, NewDenseEmptyArray(cx));
if (!array) {
return false;
}
RootedValue tmp(cx);
for (iter.switchToPrev(); !iter.done(); iter.prev()) {
const ABIResult& result = iter.cur();
if (result.onStack()) {
char* loc = stackResultsLoc.value() + result.stackOffset();
if (!ToJSValue<DebugCodegenVal>(cx, loc, result.type(), &tmp, level)) {
return false;
}
if (!NewbornArrayPush(cx, array, tmp)) {
return false;
}
} else {
if (!NewbornArrayPush(cx, array, rval)) {
return false;
}
}
}
rval.set(ObjectValue(*array));
return true;
}
class MOZ_RAII ReturnToJSResultCollector {
class MOZ_RAII StackResultsRooter : public JS::CustomAutoRooter {
ReturnToJSResultCollector& collector_;
public:
StackResultsRooter(JSContext* cx, ReturnToJSResultCollector& collector)
: JS::CustomAutoRooter(cx), collector_(collector) {}
void trace(JSTracer* trc) final {
for (ABIResultIter iter(collector_.type_); !iter.done(); iter.next()) {
const ABIResult& result = iter.cur();
if (result.onStack() && result.type().isRefRepr()) {
char* loc = collector_.stackResultsArea_.get() + result.stackOffset();
AnyRef* refLoc = reinterpret_cast<AnyRef*>(loc);
TraceNullableRoot(trc, refLoc, "StackResultsRooter::trace");
}
}
}
};
friend class StackResultsRooter;
ResultType type_;
UniquePtr<char[], JS::FreePolicy> stackResultsArea_;
Maybe<StackResultsRooter> rooter_;
public:
explicit ReturnToJSResultCollector(const ResultType& type) : type_(type){};
bool init(JSContext* cx) {
bool needRooter = false;
ABIResultIter iter(type_);
for (; !iter.done(); iter.next()) {
const ABIResult& result = iter.cur();
if (result.onStack() && result.type().isRefRepr()) {
needRooter = true;
}
}
uint32_t areaBytes = iter.stackBytesConsumedSoFar();
MOZ_ASSERT_IF(needRooter, areaBytes > 0);
if (areaBytes > 0) {
// It is necessary to zero storage for ref results, and it doesn't
// hurt to do so for other POD results.
stackResultsArea_ = cx->make_zeroed_pod_array<char>(areaBytes);
if (!stackResultsArea_) {
return false;
}
if (needRooter) {
rooter_.emplace(cx, *this);
}
}
return true;
}
void* stackResultsArea() {
MOZ_ASSERT(stackResultsArea_);
return stackResultsArea_.get();
}
bool collect(JSContext* cx, void* registerResultLoc, MutableHandleValue rval,
CoercionLevel level) {
Maybe<char*> stackResultsLoc =
stackResultsArea_ ? Some(stackResultsArea_.get()) : Nothing();
return ResultsToJSValue(cx, type_, registerResultLoc, stackResultsLoc, rval,
level);
}
};
bool Instance::callExport(JSContext* cx, uint32_t funcIndex,
const CallArgs& args, CoercionLevel level) {
if (memory0Base_) {
// If there has been a moving grow, this Instance should have been notified.
MOZ_RELEASE_ASSERT(memoryBase(0).unwrap() == memory0Base_);
}
void* interpEntry;
const FuncType* funcType;
if (!GetInterpEntryAndEnsureStubs(cx, *this, funcIndex, args, &interpEntry,
&funcType)) {
return false;
}
// Lossless coercions can handle unexposable arguments or returns. This is
// only available in testing code.
if (level != CoercionLevel::Lossless && funcType->hasUnexposableArgOrRet()) {
JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr,
JSMSG_WASM_BAD_VAL_TYPE);
return false;
}
ArgTypeVector argTypes(*funcType);
ResultType resultType(ResultType::Vector(funcType->results()));
ReturnToJSResultCollector results(resultType);
if (!results.init(cx)) {
return false;
}
// The calling convention for an external call into wasm is to pass an
// array of 16-byte values where each value contains either a coerced int32
// (in the low word), or a double value (in the low dword) value, with the
// coercions specified by the wasm signature. The external entry point
// unpacks this array into the system-ABI-specified registers and stack
// memory and then calls into the internal entry point. The return value is
// stored in the first element of the array (which, therefore, must have
// length >= 1).
Vector<ExportArg, 8> exportArgs(cx);
if (!exportArgs.resize(
std::max<size_t>(1, argTypes.lengthWithStackResults()))) {
return false;
}
Rooted<GCVector<AnyRef, 8, SystemAllocPolicy>> refs(cx);
DebugCodegen(DebugChannel::Function, "wasm-function[%d] arguments [",
funcIndex);
RootedValue v(cx);
for (size_t i = 0; i < argTypes.lengthWithStackResults(); ++i) {
void* rawArgLoc = &exportArgs[i];
if (argTypes.isSyntheticStackResultPointerArg(i)) {
*reinterpret_cast<void**>(rawArgLoc) = results.stackResultsArea();
continue;
}
size_t naturalIdx = argTypes.naturalIndex(i);
v = naturalIdx < args.length() ? args[naturalIdx] : UndefinedValue();
ValType type = funcType->arg(naturalIdx);
if (!ToWebAssemblyValue<DebugCodegenVal>(cx, v, type, rawArgLoc, true,
level)) {
return false;
}
if (type.isRefRepr()) {
void* ptr = *reinterpret_cast<void**>(rawArgLoc);
// Store in rooted array until no more GC is possible.
RootedAnyRef ref(cx, AnyRef::fromCompiledCode(ptr));
if (!refs.emplaceBack(ref.get())) {
return false;
}
DebugCodegen(DebugChannel::Function, "/(#%d)", int(refs.length() - 1));
}
}
// Copy over reference values from the rooted array, if any.
if (refs.length() > 0) {
DebugCodegen(DebugChannel::Function, "; ");
size_t nextRef = 0;
for (size_t i = 0; i < argTypes.lengthWithStackResults(); ++i) {
if (argTypes.isSyntheticStackResultPointerArg(i)) {
continue;
}
size_t naturalIdx = argTypes.naturalIndex(i);
ValType type = funcType->arg(naturalIdx);
if (type.isRefRepr()) {
AnyRef* rawArgLoc = (AnyRef*)&exportArgs[i];
*rawArgLoc = refs[nextRef++];
DebugCodegen(DebugChannel::Function, " ref(#%d) := %p ",
int(nextRef - 1), *(void**)rawArgLoc);
}
}
refs.clear();
}
DebugCodegen(DebugChannel::Function, "]\n");
// Ensure pending exception is cleared before and after (below) call.
MOZ_ASSERT(pendingException_.isNull());
{
JitActivation activation(cx);
// Call the per-exported-function trampoline created by GenerateEntry.
auto funcPtr = JS_DATA_TO_FUNC_PTR(ExportFuncPtr, interpEntry);
if (!CALL_GENERATED_2(funcPtr, exportArgs.begin(), this)) {
return false;
}
}
MOZ_ASSERT(pendingException_.isNull());
if (isAsmJS() && args.isConstructing()) {
// By spec, when a JS function is called as a constructor and this
// function returns a primary type, which is the case for all asm.js
// exported functions, the returned value is discarded and an empty
// object is returned instead.
PlainObject* obj = NewPlainObject(cx);
if (!obj) {
return false;
}
args.rval().set(ObjectValue(*obj));
return true;
}
// Note that we're not rooting the register result, if any; we depend
// on ResultsCollector::collect to root the value on our behalf,
// before causing any GC.
void* registerResultLoc = &exportArgs[0];
DebugCodegen(DebugChannel::Function, "wasm-function[%d]; results [",
funcIndex);
if (!results.collect(cx, registerResultLoc, args.rval(), level)) {
return false;
}
DebugCodegen(DebugChannel::Function, "]\n");
return true;
}
void Instance::setPendingException(Handle<WasmExceptionObject*> exn) {
pendingException_ = AnyRef::fromJSObject(*exn.get());
pendingExceptionTag_ =
AnyRef::fromJSObject(exn->as<WasmExceptionObject>().tag());
}
void Instance::constantGlobalGet(uint32_t globalIndex,
MutableHandleVal result) {
MOZ_RELEASE_ASSERT(globalIndex < maxInitializedGlobalsIndexPlus1_);
const GlobalDesc& global = metadata().globals[globalIndex];
// Constant globals are baked into the code and never stored in global data.
if (global.isConstant()) {
// We can just re-evaluate the global initializer to get the value.
result.set(Val(global.constantValue()));
return;
}
// Otherwise, we need to load the initialized value from its cell.
const void* cell = addressOfGlobalCell(global);
result.address()->initFromHeapLocation(global.type(), cell);
}
bool Instance::constantRefFunc(uint32_t funcIndex,
MutableHandleFuncRef result) {
void* fnref = Instance::refFunc(this, funcIndex);
if (fnref == AnyRef::invalid().forCompiledCode()) {
return false; // OOM, which has already been reported.
}
result.set(FuncRef::fromCompiledCode(fnref));
return true;
}
WasmStructObject* Instance::constantStructNewDefault(JSContext* cx,
uint32_t typeIndex) {
// We assume that constant structs will have a long lifetime and hence
// allocate them directly in the tenured heap. Also, we have to dynamically
// decide whether an OOL storage area is required. This is slow(er); do not
// call here from generated code.
TypeDefInstanceData* typeDefData = typeDefInstanceData(typeIndex);
const wasm::TypeDef* typeDef = typeDefData->typeDef;
MOZ_ASSERT(typeDef->kind() == wasm::TypeDefKind::Struct);
uint32_t totalBytes = typeDef->structType().size_;
bool needsOOL = WasmStructObject::requiresOutlineBytes(totalBytes);
return needsOOL ? WasmStructObject::createStructOOL<true>(cx, typeDefData,
gc::Heap::Tenured)
: WasmStructObject::createStructIL<true>(cx, typeDefData,
gc::Heap::Tenured);
}
WasmArrayObject* Instance::constantArrayNewDefault(JSContext* cx,
uint32_t typeIndex,
uint32_t numElements) {
TypeDefInstanceData* typeDefData = typeDefInstanceData(typeIndex);
// We assume that constant arrays will have a long lifetime and hence
// allocate them directly in the tenured heap.
return WasmArrayObject::createArray<true>(cx, typeDefData, gc::Heap::Tenured,
numElements);
}
JSAtom* Instance::getFuncDisplayAtom(JSContext* cx, uint32_t funcIndex) const {
// The "display name" of a function is primarily shown in Error.stack which
// also includes location, so use getFuncNameBeforeLocation.
UTF8Bytes name;
if (!metadata().getFuncNameBeforeLocation(funcIndex, &name)) {
return nullptr;
}
return AtomizeUTF8Chars(cx, name.begin(), name.length());
}
void Instance::ensureProfilingLabels(bool profilingEnabled) const {
return code_->ensureProfilingLabels(profilingEnabled);
}
void Instance::onMovingGrowMemory(const WasmMemoryObject* memory) {
MOZ_ASSERT(!isAsmJS());
MOZ_ASSERT(!memory->isShared());
for (uint32_t i = 0; i < metadata().memories.length(); i++) {
MemoryInstanceData& md = memoryInstanceData(i);
if (memory != md.memory) {
continue;
}
ArrayBufferObject& buffer = md.memory->buffer().as<ArrayBufferObject>();
md.base = buffer.dataPointer();
size_t limit = md.memory->boundsCheckLimit();
#if !defined(JS_64BIT)
// We assume that the limit is a 32-bit quantity
MOZ_ASSERT(limit <= UINT32_MAX);
#endif
md.boundsCheckLimit = limit;
if (i == 0) {
memory0Base_ = md.base;
memory0BoundsCheckLimit_ = md.boundsCheckLimit;
}
}
}
void Instance::onMovingGrowTable(const Table* table) {
MOZ_ASSERT(!isAsmJS());
// `table` has grown and we must update cached data for it. Importantly,
// we can have cached those data in more than one location: we'll have
// cached them once for each time the table was imported into this instance.
//
// When an instance is registered as an observer of a table it is only
// registered once, regardless of how many times the table was imported.
// Thus when a table is grown, onMovingGrowTable() is only invoked once for
// the table.
//
// Ergo we must go through the entire list of tables in the instance here
// and check for the table in all the cached-data slots; we can't exit after
// the first hit.
for (uint32_t i = 0; i < tables_.length(); i++) {
if (tables_[i] != table) {
continue;
}
TableInstanceData& table = tableInstanceData(i);
table.length = tables_[i]->length();
table.elements = tables_[i]->instanceElements();
}
}
JSString* Instance::createDisplayURL(JSContext* cx) {
// In the best case, we simply have a URL, from a streaming compilation of a
// fetched Response.
if (metadata().filenameIsURL) {
const char* filename = metadata().filename.get();
return NewStringCopyUTF8N(cx, JS::UTF8Chars(filename, strlen(filename)));
}
// Otherwise, build wasm module URL from following parts:
// - "wasm:" as protocol;
// - URI encoded filename from metadata (if can be encoded), plus ":";
// - 64-bit hash of the module bytes (as hex dump).
JSStringBuilder result(cx);
if (!result.append("wasm:")) {
return nullptr;
}
if (const char* filename = metadata().filename.get()) {
// EncodeURI returns false due to invalid chars or OOM -- fail only
// during OOM.
JSString* filenamePrefix = EncodeURI(cx, filename, strlen(filename));
if (!filenamePrefix) {
if (cx->isThrowingOutOfMemory()) {
return nullptr;
}
MOZ_ASSERT(!cx->isThrowingOverRecursed());
cx->clearPendingException();
return nullptr;
}
if (!result.append(filenamePrefix)) {
return nullptr;
}
}
if (metadata().debugEnabled) {
if (!result.append(":")) {
return nullptr;
}
const ModuleHash& hash = metadata().debugHash;
for (unsigned char byte : hash) {
unsigned char digit1 = byte / 16, digit2 = byte % 16;
if (!result.append(
(char)(digit1 < 10 ? digit1 + '0' : digit1 + 'a' - 10))) {
return nullptr;
}
if (!result.append(
(char)(digit2 < 10 ? digit2 + '0' : digit2 + 'a' - 10))) {
return nullptr;
}
}
}
return result.finishString();
}
WasmBreakpointSite* Instance::getOrCreateBreakpointSite(JSContext* cx,
uint32_t offset) {
MOZ_ASSERT(debugEnabled());
return debug().getOrCreateBreakpointSite(cx, this, offset);
}
void Instance::destroyBreakpointSite(JS::GCContext* gcx, uint32_t offset) {
MOZ_ASSERT(debugEnabled());
return debug().destroyBreakpointSite(gcx, this, offset);
}
void Instance::disassembleExport(JSContext* cx, uint32_t funcIndex, Tier tier,
PrintCallback printString) const {
const MetadataTier& metadataTier = metadata(tier);
const FuncExport& funcExport = metadataTier.lookupFuncExport(funcIndex);
const CodeRange& range = metadataTier.codeRange(funcExport);
const CodeTier& codeTier = code(tier);
const ModuleSegment& segment = codeTier.segment();
MOZ_ASSERT(range.begin() < segment.length());
MOZ_ASSERT(range.end() < segment.length());
uint8_t* functionCode = segment.base() + range.begin();
jit::Disassemble(functionCode, range.end() - range.begin(), printString);
}
void Instance::addSizeOfMisc(MallocSizeOf mallocSizeOf,
Metadata::SeenSet* seenMetadata,
Code::SeenSet* seenCode,
Table::SeenSet* seenTables, size_t* code,
size_t* data) const {
*data += mallocSizeOf(this);
for (const SharedTable& table : tables_) {
*data += table->sizeOfIncludingThisIfNotSeen(mallocSizeOf, seenTables);
}
if (maybeDebug_) {
maybeDebug_->addSizeOfMisc(mallocSizeOf, seenMetadata, seenCode, code,
data);
}
code_->addSizeOfMiscIfNotSeen(mallocSizeOf, seenMetadata, seenCode, code,
data);
}
//////////////////////////////////////////////////////////////////////////////
//
// Reporting of errors that are traps.
void wasm::ReportTrapError(JSContext* cx, unsigned errorNumber) {
JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr, errorNumber);
if (cx->isThrowingOutOfMemory()) {
return;
}
// Mark the exception as thrown from a trap to prevent if from being handled
// by wasm exception handlers.
RootedValue exn(cx);
if (!cx->getPendingException(&exn)) {
return;
}
MOZ_ASSERT(exn.isObject() && exn.toObject().is<ErrorObject>());
exn.toObject().as<ErrorObject>().setFromWasmTrap();
}