ladybird/Kernel/Devices/KCOVDevice.h
Andreas Kling 30861daa93 Kernel: Simplify the File memory-mapping API
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.
2022-08-24 14:57:51 +02:00

41 lines
1.4 KiB
C++

/*
* Copyright (c) 2021, Patrick Meyer <git@the-space.agency>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <Kernel/Devices/CharacterDevice.h>
#include <Kernel/Devices/KCOVInstance.h>
namespace Kernel {
class KCOVDevice final : public CharacterDevice {
friend class DeviceManagement;
public:
static HashMap<ProcessID, KCOVInstance*>* proc_instance;
static HashMap<ThreadID, KCOVInstance*>* thread_instance;
static NonnullLockRefPtr<KCOVDevice> must_create();
static void free_thread();
static void free_process();
// ^File
ErrorOr<NonnullLockRefPtr<Memory::VMObject>> vmobject_for_mmap(Process&, Memory::VirtualRange const&, u64& offset, bool shared) override;
ErrorOr<NonnullLockRefPtr<OpenFileDescription>> open(int options) override;
protected:
KCOVDevice();
virtual StringView class_name() const override { return "KCOVDevice"sv; }
virtual bool can_read(OpenFileDescription const&, u64) const override final { return true; }
virtual bool can_write(OpenFileDescription const&, u64) const override final { return true; }
virtual ErrorOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override { return EINVAL; }
virtual ErrorOr<size_t> write(OpenFileDescription&, u64, UserOrKernelBuffer const&, size_t) override { return EINVAL; }
virtual ErrorOr<void> ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg) override;
};
}