ladybird/Kernel/UserOrKernelBuffer.cpp

89 lines
2.2 KiB
C++

/*
* Copyright (c) 2020, the SerenityOS developers.
*
* 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));
}
String UserOrKernelBuffer::copy_into_string(size_t size) const
{
if (!m_buffer)
return {};
if (Memory::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 });
}
KResultOr<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 = KString::try_create_uninitialized(size, buffer);
if (!kstring)
return ENOMEM;
if (!copy_from_user(buffer, m_buffer, size))
return EFAULT;
return kstring.release_nonnull();
}
auto kstring = KString::try_create(ReadonlyBytes { m_buffer, size });
if (!kstring)
return ENOMEM;
return kstring.release_nonnull();
}
bool UserOrKernelBuffer::write(const void* src, size_t offset, size_t len)
{
if (!m_buffer)
return false;
if (Memory::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 (Memory::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 (Memory::is_user_address(VirtualAddress(m_buffer)))
return memset_user(m_buffer + offset, value, len);
::memset(m_buffer + offset, value, len);
return true;
}
}