mirror of
https://github.com/RGBCube/serenity
synced 2025-10-31 03:12:44 +00:00
30861daa93
Before this change, we had File::mmap() which did all the work of setting up a VMObject, and then creating a Region in the current process's address space. This patch simplifies the interface by removing the region part. Files now only have to return a suitable VMObject from vmobject_for_mmap(), and then sys$mmap() itself will take care of actually mapping it into the address space. This fixes an issue where we'd try to block on I/O (for inode metadata lookup) while holding the address space spinlock. It also reduces time spent holding the address space lock.
37 lines
1.2 KiB
C++
37 lines
1.2 KiB
C++
/*
|
|
* Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/Types.h>
|
|
#include <Kernel/Devices/CharacterDevice.h>
|
|
#include <Kernel/PhysicalAddress.h>
|
|
|
|
namespace Kernel {
|
|
|
|
class MemoryDevice final : public CharacterDevice {
|
|
friend class DeviceManagement;
|
|
|
|
public:
|
|
static NonnullLockRefPtr<MemoryDevice> must_create();
|
|
~MemoryDevice();
|
|
|
|
virtual ErrorOr<NonnullLockRefPtr<Memory::VMObject>> vmobject_for_mmap(Process&, Memory::VirtualRange const&, u64& offset, bool shared) override;
|
|
|
|
private:
|
|
MemoryDevice();
|
|
|
|
virtual StringView class_name() const override { return "MemoryDevice"sv; }
|
|
virtual bool can_read(OpenFileDescription const&, u64) const override { return true; }
|
|
virtual bool can_write(OpenFileDescription const&, u64) const override { return false; }
|
|
virtual bool is_seekable() const override { return true; }
|
|
virtual ErrorOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override;
|
|
virtual ErrorOr<size_t> write(OpenFileDescription&, u64, UserOrKernelBuffer const&, size_t) override { return EINVAL; }
|
|
|
|
bool is_allowed_range(PhysicalAddress, Memory::VirtualRange const&) const;
|
|
};
|
|
|
|
}
|