Atmosphere/exosphere2/program/source/smc/secmon_user_page_mapper.cpp

/*
 * Copyright (c) 2018-2020 Atmosphère-NX
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <exosphere.hpp>
#include "../secmon_map.hpp"
#include "secmon_user_page_mapper.hpp"

namespace ams::secmon::smc {

    bool UserPageMapper::Map() {
        this->virtual_address = MapSmcUserPage(this->physical_address);
        return this->virtual_address != 0;
    }

    void *UserPageMapper::GetPointerTo(uintptr_t phys, size_t size) const {
        /* Ensure we stay within the page. */
        if (util::AlignDown(phys, 4_KB) != this->physical_address) {
            return nullptr;
        }
        if (size != 0) {
            if (util::AlignDown(phys + size - 1, 4_KB) != this->physical_address) {
                return nullptr;
            }
        }

        return reinterpret_cast<void *>(phys + (this->virtual_address - this->physical_address));
    }

    bool UserPageMapper::CopyToUser(uintptr_t dst_phys, const void *src, size_t size) const {
        void * const dst = this->GetPointerTo(dst_phys, size);
        if (dst == nullptr) {
            return false;
        }

        std::memcpy(dst, src, size);
        return true;
    }

    bool UserPageMapper::CopyFromUser(void *dst, uintptr_t src_phys, size_t size) const {
        const void * const src = this->GetPointerTo(src_phys, size);
        if (src == nullptr) {
            return false;
        }

        std::memcpy(dst, src, size);
        return true;
    }

}