~mmach/netext73/webkit2gtk

/*

 * Copyright (C) 2019 Apple Inc. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

 

#pragma once

 

#include "CellSize.h"

#include "VMInspector.h"

#include <wtf/Assertions.h>

 

namespace JSC {

 

#define AUDIT_CONDITION(x) (x), #x

#define AUDIT_VERIFY(action, verifier, cond, ...) do { \

        if (action == VerifierAction::ReleaseAssert) \

            RELEASE_ASSERT(cond, __VA_ARGS__); \

        else if (!verifier(AUDIT_CONDITION(cond), __VA_ARGS__)) \

            return false; \

    } while (false)

 

template<VMInspector::VerifierAction action, VMInspector::VerifyFunctor verifier>

bool VMInspector::verifyCellSize(VM& vm, JSCell* cell, size_t allocatorCellSize)

{

    Structure* structure = cell->structure(vm);

    const ClassInfo* classInfo = structure->classInfo();

    JSType cellType = cell->type();

    AUDIT_VERIFY(action, verifier, cellType == structure->m_blob.type(), cell, cellType, structure->m_blob.type());

 

    size_t size = cellSize(vm, cell);

    AUDIT_VERIFY(action, verifier, size <= allocatorCellSize, cell, cellType, size, allocatorCellSize, classInfo->staticClassSize);

    if (isDynamicallySizedType(cellType))

        AUDIT_VERIFY(action, verifier, size >= classInfo->staticClassSize, cell, cellType, size, classInfo->staticClassSize);

 

    return true;

}

 

template<VMInspector::VerifierAction action, VMInspector::VerifyFunctor verifier>

bool VMInspector::verifyCell(VM& vm, JSCell* cell)

{

    size_t allocatorCellSize = 0;

    if (cell->isPreciseAllocation()) {

        PreciseAllocation& preciseAllocation = cell->preciseAllocation();

        AUDIT_VERIFY(action, verifier, &preciseAllocation.vm() == &vm, cell, cell->type(), &preciseAllocation.vm(), &vm);

 

        bool isValidPreciseAllocation = false;

        for (auto* i : vm.heap.objectSpace().preciseAllocations()) {

            if (i == &preciseAllocation) {

                isValidPreciseAllocation = true;

                break;

            }

        }

        AUDIT_VERIFY(action, verifier, isValidPreciseAllocation, cell, cell->type());

 

        allocatorCellSize = preciseAllocation.cellSize();

    } else {

        MarkedBlock& block = cell->markedBlock();

        MarkedBlock::Handle& blockHandle = block.handle();

        AUDIT_VERIFY(action, verifier, &block.vm() == &vm, cell, cell->type(), &block.vm(), &vm);

 

        uintptr_t blockStartAddress = reinterpret_cast<uintptr_t>(blockHandle.start());

        AUDIT_VERIFY(action, verifier, blockHandle.contains(cell), cell, cell->type(), blockStartAddress, blockHandle.end());

 

        uintptr_t cellAddress = reinterpret_cast<uintptr_t>(cell);

        uintptr_t cellOffset = cellAddress - blockStartAddress;

        allocatorCellSize = block.cellSize();

        bool cellIsProperlyAligned = !(cellOffset % allocatorCellSize);

        AUDIT_VERIFY(action, verifier, cellIsProperlyAligned, cell, cell->type(), allocatorCellSize);

    }

 

    auto cellType = cell->type();

    if (cell->type() != JSImmutableButterflyType)

        AUDIT_VERIFY(action, verifier, !Gigacage::contains(cell), cell, cellType);

 

    if (!verifyCellSize<action, verifier>(vm, cell, allocatorCellSize))

        return false;

 

    if (Gigacage::isEnabled(Gigacage::JSValue) && cell->isObject()) {

        JSObject* object = asObject(cell);

        const Butterfly* butterfly = object->butterfly();

        AUDIT_VERIFY(action, verifier, !butterfly || Gigacage::isCaged(Gigacage::JSValue, butterfly), cell, cell->type(), butterfly);

    }

 

    return true;

}

 

#undef AUDIT_VERIFY

#undef AUDIT_CONDITION

 

} // namespace JSC