/* * Copyright (C) 2018 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. */ #include "config.h" #include "SpectreGadget.h" #include "RuntimeEnabledFeatures.h" namespace WebCore { inline SpectreGadget::SpectreGadget(const String& text) { if (RuntimeEnabledFeatures::sharedFeatures().spectreGadgetsEnabled()) { m_data.resize(text.length()); setReadLength(text.length()); m_data.fill(0); m_dataPtr = m_data.data(); for (size_t i = 0; i < m_readLength; i++) m_data[i] = text.characterAt(i); } else { setReadLength(0); m_dataPtr = nullptr; } } Ref<SpectreGadget> SpectreGadget::create(const String& text) { return adoptRef(*new SpectreGadget(text)); } void SpectreGadget::setReadLength(size_t readLength) { m_readLength = std::min(readLength, m_data.size()); } unsigned SpectreGadget::charCodeAt(size_t index) { if (index < m_readLength) return m_dataPtr[index]; return 0; } void SpectreGadget::clflushReadLength() { #if CPU(X86_64) && !OS(WINDOWS) auto clflush = [] (void* ptr) { char* ptrToFlush = static_cast<char*>(ptr); asm volatile ("clflush %0" :: "m"(*ptrToFlush) : "memory"); }; clflush(&m_readLength); #endif } } // namespace WebCore