ladybird/Kernel/Devices/FullDevice.cpp
Gunnar Beutner 1ce32ef675 Kernel: Let the user read/write more than one page from/to dev files
Previously reads and writes to /dev/zero, /dev/full, /dev/null and
/dev/random were limited to 4096 bytes.

This removes that restriction so that users can enjoy more zero bytes
in their buffers.
2021-05-27 09:30:19 +02:00

43 lines
827 B
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "FullDevice.h"
#include <AK/Memory.h>
#include <AK/StdLibExtras.h>
#include <Kernel/Arch/x86/CPU.h>
#include <LibC/errno_numbers.h>
namespace Kernel {
UNMAP_AFTER_INIT FullDevice::FullDevice()
: CharacterDevice(1, 7)
{
}
UNMAP_AFTER_INIT FullDevice::~FullDevice()
{
}
bool FullDevice::can_read(const FileDescription&, size_t) const
{
return true;
}
KResultOr<size_t> FullDevice::read(FileDescription&, u64, UserOrKernelBuffer& buffer, size_t size)
{
if (!buffer.memset(0, size))
return EFAULT;
return size;
}
KResultOr<size_t> FullDevice::write(FileDescription&, u64, const UserOrKernelBuffer&, size_t size)
{
if (size == 0)
return 0;
return ENOSPC;
}
}