ladybird/Kernel/Devices/MemoryDevice.cpp
sin-ack 4bfd6e41b9 Kernel: Make Kernel::VMObject allocation functions return KResultOr
This makes for nicer handling of errors compared to checking whether a
RefPtr is null. Additionally, this will give way to return different
types of errors in the future.
2021-08-15 15:41:02 +02:00

65 lines
1.8 KiB
C++

/*
* Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Memory.h>
#include <AK/StdLibExtras.h>
#include <Kernel/Arch/PC/BIOS.h>
#include <Kernel/Devices/MemoryDevice.h>
#include <Kernel/Memory/AnonymousVMObject.h>
#include <Kernel/Sections.h>
namespace Kernel {
UNMAP_AFTER_INIT NonnullRefPtr<MemoryDevice> MemoryDevice::must_create()
{
return adopt_ref(*new MemoryDevice);
}
UNMAP_AFTER_INIT MemoryDevice::MemoryDevice()
: CharacterDevice(1, 1)
{
}
UNMAP_AFTER_INIT MemoryDevice::~MemoryDevice()
{
}
KResultOr<size_t> MemoryDevice::read(FileDescription&, u64, UserOrKernelBuffer&, size_t)
{
TODO();
}
void MemoryDevice::did_seek(FileDescription&, off_t)
{
TODO();
}
KResultOr<Memory::Region*> MemoryDevice::mmap(Process& process, FileDescription&, Memory::VirtualRange const& range, u64 offset, int prot, bool shared)
{
auto viewed_address = PhysicalAddress(offset);
dbgln("MemoryDevice: Trying to mmap physical memory at {} for range of {} bytes", viewed_address, range.size());
if (!MM.is_allowed_to_mmap_to_userspace(viewed_address, range)) {
dbgln("MemoryDevice: Trying to mmap physical memory at {} for range of {} bytes failed due to violation of access", viewed_address, range.size());
return EINVAL;
}
auto maybe_vmobject = Memory::AnonymousVMObject::try_create_for_physical_range(viewed_address, range.size());
if (maybe_vmobject.is_error())
return maybe_vmobject.error();
dbgln("MemoryDevice: Mapped physical memory at {} for range of {} bytes", viewed_address, range.size());
return process.address_space().allocate_region_with_vmobject(
range,
maybe_vmobject.release_value(),
0,
"Mapped Physical Memory",
prot,
shared);
}
}