RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 05:28:11 +00:00
Code Issues Activity Actions

Kernel: Move a bunch of generic devices code into new subdirectory

Browse source
This commit is contained in:
Liav A 2023-03-18 13:17:13 +02:00 • committed by Jelle Raaijmakers
parent 9eeda5719e
commit 4617c05a08
27 changed files with 34 additions and 34 deletions
Download patch file Download diff file Expand all files Collapse all files

66
Kernel/Devices/MemoryDevice.cpp
View file

@ -1,66 +0,0 @@
/*
* Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Devices/DeviceManagement.h>
#include <Kernel/Devices/MemoryDevice.h>
#include <Kernel/Memory/AnonymousVMObject.h>
#include <Kernel/Memory/TypedMapping.h>
#include <Kernel/Sections.h>
namespace Kernel {
UNMAP_AFTER_INIT NonnullLockRefPtr<MemoryDevice> MemoryDevice::must_create()
{
auto memory_device_or_error = DeviceManagement::try_create_device<MemoryDevice>();
// FIXME: Find a way to propagate errors
VERIFY(!memory_device_or_error.is_error());
return memory_device_or_error.release_value();
}
UNMAP_AFTER_INIT MemoryDevice::MemoryDevice()
: CharacterDevice(1, 1)
{
}
UNMAP_AFTER_INIT MemoryDevice::~MemoryDevice() = default;
ErrorOr<size_t> MemoryDevice::read(OpenFileDescription&, u64 offset, UserOrKernelBuffer& buffer, size_t length)
{
if (!MM.is_allowed_to_read_physical_memory_for_userspace(PhysicalAddress(offset), length)) {
dbgln_if(MEMORY_DEVICE_DEBUG, "MemoryDevice: Trying to read physical memory at {} for range of {} bytes failed due to violation of access", PhysicalAddress(offset), length);
return EINVAL;
}
auto mapping = TRY(Memory::map_typed<u8>(PhysicalAddress(offset), length));
auto bytes = ReadonlyBytes { mapping.ptr(), length };
TRY(buffer.write(bytes));
return length;
}
ErrorOr<NonnullLockRefPtr<Memory::VMObject>> MemoryDevice::vmobject_for_mmap(Process&, Memory::VirtualRange const& range, u64& offset, bool)
{
auto viewed_address = PhysicalAddress(offset);
// Note: This check happens to guard against possible memory leak.
// For example, if we try to mmap physical memory from 0x1000 to 0x2000 and you
// can actually mmap only from 0x1001, then we would fail as usual.
// However, in such case if we mmap from 0x1002, we are technically not violating
// any rules, besides the fact that we mapped an entire page with two bytes which we
// were not supposed to see. To prevent that, if we use mmap(2) syscall, we should
// always consider the start page to be aligned on PAGE_SIZE, or to be more precise
// is to be set to the page base of that start address.
VERIFY(viewed_address == viewed_address.page_base());
if (!MM.is_allowed_to_read_physical_memory_for_userspace(viewed_address, range.size())) {
dbgln_if(MEMORY_DEVICE_DEBUG, "MemoryDevice: Trying to mmap physical memory at {} for range of {} bytes failed due to violation of access", viewed_address, range.size());
return EINVAL;
}
offset = 0;
return TRY(Memory::AnonymousVMObject::try_create_for_physical_range(viewed_address, range.size()));
}
}