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UserOrKernelBuffer.cpp
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UserOrKernelBuffer.cpp
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/*
* Copyright (c) 2020, the SerenityOS developers.
* 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT HOLDER 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 <Kernel/UserOrKernelBuffer.h>
#include <Kernel/VM/MemoryManager.h>
namespace Kernel {
bool UserOrKernelBuffer::is_kernel_buffer() const
{
return !is_user_address(VirtualAddress(m_buffer));
}
String UserOrKernelBuffer::copy_into_string(size_t size) const
{
if (!m_buffer)
return {};
if (is_user_address(VirtualAddress(m_buffer))) {
char* buffer;
auto data_copy = StringImpl::create_uninitialized(size, buffer);
if (!copy_from_user(buffer, m_buffer, size))
return {};
return data_copy;
}
return String(ReadonlyBytes { m_buffer, size });
}
bool UserOrKernelBuffer::write(const void* src, size_t offset, size_t len)
{
if (!m_buffer)
return false;
if (is_user_address(VirtualAddress(m_buffer)))
return copy_to_user(m_buffer + offset, src, len);
memcpy(m_buffer + offset, src, len);
return true;
}
bool UserOrKernelBuffer::read(void* dest, size_t offset, size_t len) const
{
if (!m_buffer)
return false;
if (is_user_address(VirtualAddress(m_buffer)))
return copy_from_user(dest, m_buffer + offset, len);
memcpy(dest, m_buffer + offset, len);
return true;
}
bool UserOrKernelBuffer::memset(int value, size_t offset, size_t len)
{
if (!m_buffer)
return false;
if (is_user_address(VirtualAddress(m_buffer)))
return memset_user(m_buffer + offset, value, len);
::memset(m_buffer + offset, value, len);
return true;
}
}