ladybird/Kernel/Memory/InodeVMObject.h
Andreas Kling d3e8eb5918 Kernel: Make file-backed memory regions remember description permissions
This allows sys$mprotect() to honor the original readable & writable
flags of the open file description as they were at the point we did the
original sys$mmap().

IIUC, this is what Dr. POSIX wants us to do:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mprotect.html

Also, remove the bogus and racy "W^X" checking we did against mappings
based on their current inode metadata. If we want to do this, we can do
it properly. For now, it was not only racy, but also did blocking I/O
while holding a spinlock.
2022-08-24 14:57:51 +02:00

44 lines
1.1 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Bitmap.h>
#include <Kernel/Memory/VMObject.h>
#include <Kernel/UnixTypes.h>
namespace Kernel::Memory {
class InodeVMObject : public VMObject {
public:
virtual ~InodeVMObject() override;
Inode& inode() { return *m_inode; }
Inode const& inode() const { return *m_inode; }
size_t amount_dirty() const;
size_t amount_clean() const;
int release_all_clean_pages();
int try_release_clean_pages(int page_amount);
u32 writable_mappings() const;
protected:
explicit InodeVMObject(Inode&, FixedArray<LockRefPtr<PhysicalPage>>&&, Bitmap dirty_pages);
explicit InodeVMObject(InodeVMObject const&, FixedArray<LockRefPtr<PhysicalPage>>&&, Bitmap dirty_pages);
InodeVMObject& operator=(InodeVMObject const&) = delete;
InodeVMObject& operator=(InodeVMObject&&) = delete;
InodeVMObject(InodeVMObject&&) = delete;
virtual bool is_inode() const final { return true; }
NonnullLockRefPtr<Inode> m_inode;
Bitmap m_dirty_pages;
};
}