ladybird/Kernel/UserOrKernelBuffer.cpp

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/*
* Copyright (c) 2020, the SerenityOS developers.
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Memory/MemoryManager.h>
#include <Kernel/UserOrKernelBuffer.h>
namespace Kernel {
bool UserOrKernelBuffer::is_kernel_buffer() const
{
return !Memory::is_user_address(VirtualAddress(m_buffer));
}
ErrorOr<NonnullOwnPtr<KString>> UserOrKernelBuffer::try_copy_into_kstring(size_t size) const
{
if (!m_buffer)
return EINVAL;
if (Memory::is_user_address(VirtualAddress(m_buffer))) {
char* buffer;
auto kstring = TRY(KString::try_create_uninitialized(size, buffer));
TRY(copy_from_user(buffer, m_buffer, size));
return kstring;
}
return KString::try_create(ReadonlyBytes { m_buffer, size });
}
ErrorOr<void> UserOrKernelBuffer::write(void const* src, size_t offset, size_t len)
{
if (!m_buffer)
return EFAULT;
if (Memory::is_user_address(VirtualAddress(m_buffer)))
return copy_to_user(m_buffer + offset, src, len);
memcpy(m_buffer + offset, src, len);
return {};
}
ErrorOr<void> UserOrKernelBuffer::read(void* dest, size_t offset, size_t len) const
{
if (!m_buffer)
return EFAULT;
if (Memory::is_user_address(VirtualAddress(m_buffer)))
return copy_from_user(dest, m_buffer + offset, len);
memcpy(dest, m_buffer + offset, len);
return {};
}
ErrorOr<void> UserOrKernelBuffer::memset(int value, size_t offset, size_t len)
{
if (!m_buffer)
return EFAULT;
if (Memory::is_user_address(VirtualAddress(m_buffer)))
return memset_user(m_buffer + offset, value, len);
::memset(m_buffer + offset, value, len);
return {};
}
}