ladybird/Kernel/Memory/Region.h
Timothy Flynn c911781c21 Everywhere: Remove needless trailing semi-colons after functions
This is a new option in clang-format-16.
2023-07-08 10:32:56 +01:00

286 lines
9.9 KiB
C++

/*
* Copyright (c) 2018-2022, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2022, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/EnumBits.h>
#include <AK/IntrusiveList.h>
#include <AK/IntrusiveRedBlackTree.h>
#include <Kernel/Forward.h>
#include <Kernel/Library/KString.h>
#include <Kernel/Library/LockWeakable.h>
#include <Kernel/Locking/LockRank.h>
#include <Kernel/Memory/PageFaultResponse.h>
#include <Kernel/Memory/VirtualRange.h>
#include <Kernel/Sections.h>
#include <Kernel/UnixTypes.h>
namespace Kernel {
class PageFault;
}
namespace Kernel::Memory {
enum class ShouldFlushTLB {
No,
Yes,
};
class Region final
: public LockWeakable<Region> {
friend class AddressSpace;
friend class MemoryManager;
friend class RegionTree;
public:
enum Access : u8 {
None = 0,
Read = 1,
Write = 2,
Execute = 4,
HasBeenReadable = 16,
HasBeenWritable = 32,
HasBeenExecutable = 64,
ReadOnly = Read,
ReadWrite = Read | Write,
ReadWriteExecute = Read | Write | Execute,
};
enum class Cacheable {
No = 0,
Yes,
};
static ErrorOr<NonnullOwnPtr<Region>> try_create_user_accessible(VirtualRange const&, NonnullLockRefPtr<VMObject>, size_t offset_in_vmobject, OwnPtr<KString> name, Region::Access access, Cacheable, bool shared);
static ErrorOr<NonnullOwnPtr<Region>> create_unbacked();
static ErrorOr<NonnullOwnPtr<Region>> create_unplaced(NonnullLockRefPtr<VMObject>, size_t offset_in_vmobject, OwnPtr<KString> name, Region::Access access, Cacheable = Cacheable::Yes, bool shared = false);
~Region();
[[nodiscard]] VirtualRange const& range() const { return m_range; }
[[nodiscard]] VirtualAddress vaddr() const { return m_range.base(); }
[[nodiscard]] size_t size() const { return m_range.size(); }
[[nodiscard]] bool is_readable() const { return (m_access & Access::Read) == Access::Read; }
[[nodiscard]] bool is_writable() const { return (m_access & Access::Write) == Access::Write; }
[[nodiscard]] bool is_executable() const { return (m_access & Access::Execute) == Access::Execute; }
[[nodiscard]] bool has_been_readable() const { return (m_access & Access::HasBeenReadable) == Access::HasBeenReadable; }
[[nodiscard]] bool has_been_writable() const { return (m_access & Access::HasBeenWritable) == Access::HasBeenWritable; }
[[nodiscard]] bool has_been_executable() const { return (m_access & Access::HasBeenExecutable) == Access::HasBeenExecutable; }
[[nodiscard]] bool is_cacheable() const { return m_cacheable; }
[[nodiscard]] StringView name() const { return m_name ? m_name->view() : StringView {}; }
[[nodiscard]] OwnPtr<KString> take_name() { return move(m_name); }
[[nodiscard]] Region::Access access() const { return static_cast<Region::Access>(m_access); }
void set_name(OwnPtr<KString> name) { m_name = move(name); }
[[nodiscard]] VMObject const& vmobject() const { return *m_vmobject; }
[[nodiscard]] VMObject& vmobject() { return *m_vmobject; }
void set_vmobject(NonnullLockRefPtr<VMObject>&&);
[[nodiscard]] bool is_shared() const { return m_shared; }
void set_shared(bool shared) { m_shared = shared; }
[[nodiscard]] bool is_stack() const { return m_stack; }
void set_stack(bool stack) { m_stack = stack; }
[[nodiscard]] bool is_immutable() const { return m_immutable; }
void set_immutable() { m_immutable = true; }
[[nodiscard]] bool is_mmap() const { return m_mmap; }
void set_mmap(bool mmap, bool description_was_readable, bool description_was_writable)
{
m_mmap = mmap;
m_mmapped_from_readable = description_was_readable;
m_mmapped_from_writable = description_was_writable;
}
[[nodiscard]] bool is_write_combine() const { return m_write_combine; }
ErrorOr<void> set_write_combine(bool);
[[nodiscard]] bool is_user() const { return !is_kernel(); }
[[nodiscard]] bool is_kernel() const { return vaddr().get() < USER_RANGE_BASE || vaddr().get() >= kernel_mapping_base; }
PageFaultResponse handle_fault(PageFault const&);
ErrorOr<NonnullOwnPtr<Region>> try_clone();
[[nodiscard]] bool contains(VirtualAddress vaddr) const
{
return m_range.contains(vaddr);
}
[[nodiscard]] bool contains(VirtualRange const& range) const
{
return m_range.contains(range);
}
[[nodiscard]] unsigned page_index_from_address(VirtualAddress vaddr) const
{
return (vaddr - m_range.base()).get() / PAGE_SIZE;
}
[[nodiscard]] VirtualAddress vaddr_from_page_index(size_t page_index) const
{
return vaddr().offset(page_index * PAGE_SIZE);
}
[[nodiscard]] bool translate_vmobject_page(size_t& index) const
{
auto first_index = first_page_index();
if (index < first_index) {
index = first_index;
return false;
}
index -= first_index;
auto total_page_count = this->page_count();
if (index >= total_page_count) {
index = first_index + total_page_count - 1;
return false;
}
return true;
}
[[nodiscard]] ALWAYS_INLINE size_t translate_to_vmobject_page(size_t page_index) const
{
return first_page_index() + page_index;
}
[[nodiscard]] size_t first_page_index() const
{
return m_offset_in_vmobject / PAGE_SIZE;
}
[[nodiscard]] size_t page_count() const
{
return size() / PAGE_SIZE;
}
RefPtr<PhysicalPage> physical_page(size_t index) const;
RefPtr<PhysicalPage>& physical_page_slot(size_t index);
[[nodiscard]] size_t offset_in_vmobject() const
{
return m_offset_in_vmobject;
}
[[nodiscard]] size_t offset_in_vmobject_from_vaddr(VirtualAddress vaddr) const
{
return m_offset_in_vmobject + vaddr.get() - this->vaddr().get();
}
[[nodiscard]] size_t amount_resident() const;
[[nodiscard]] size_t amount_shared() const;
[[nodiscard]] size_t amount_dirty() const;
[[nodiscard]] bool should_cow(size_t page_index) const;
ErrorOr<void> set_should_cow(size_t page_index, bool);
[[nodiscard]] size_t cow_pages() const;
void set_readable(bool b) { set_access_bit(Access::Read, b); }
void set_writable(bool b) { set_access_bit(Access::Write, b); }
void set_executable(bool b) { set_access_bit(Access::Execute, b); }
void unsafe_clear_access() { m_access = Region::None; }
void set_page_directory(PageDirectory&);
ErrorOr<void> map(PageDirectory&, ShouldFlushTLB = ShouldFlushTLB::Yes);
void unmap(ShouldFlushTLB = ShouldFlushTLB::Yes);
void unmap_with_locks_held(ShouldFlushTLB, SpinlockLocker<RecursiveSpinlock<LockRank::None>>& pd_locker);
void remap();
[[nodiscard]] bool is_mapped() const { return m_page_directory != nullptr; }
void clear_to_zero();
[[nodiscard]] bool is_syscall_region() const { return m_syscall_region; }
void set_syscall_region(bool b) { m_syscall_region = b; }
[[nodiscard]] bool mmapped_from_readable() const { return m_mmapped_from_readable; }
[[nodiscard]] bool mmapped_from_writable() const { return m_mmapped_from_writable; }
void start_handling_page_fault(Badge<MemoryManager>) { m_in_progress_page_faults++; }
void finish_handling_page_fault(Badge<MemoryManager>) { m_in_progress_page_faults--; }
private:
Region();
Region(NonnullLockRefPtr<VMObject>, size_t offset_in_vmobject, OwnPtr<KString>, Region::Access access, Cacheable, bool shared);
Region(VirtualRange const&, NonnullLockRefPtr<VMObject>, size_t offset_in_vmobject, OwnPtr<KString>, Region::Access access, Cacheable, bool shared);
[[nodiscard]] bool remap_vmobject_page(size_t page_index, NonnullRefPtr<PhysicalPage>);
void set_access_bit(Access access, bool b)
{
if (b)
m_access |= access | (access << 4);
else
m_access &= ~access;
}
[[nodiscard]] PageFaultResponse handle_cow_fault(size_t page_index);
[[nodiscard]] PageFaultResponse handle_inode_fault(size_t page_index);
[[nodiscard]] PageFaultResponse handle_zero_fault(size_t page_index, PhysicalPage& page_in_slot_at_time_of_fault);
[[nodiscard]] bool map_individual_page_impl(size_t page_index);
[[nodiscard]] bool map_individual_page_impl(size_t page_index, RefPtr<PhysicalPage>);
LockRefPtr<PageDirectory> m_page_directory;
VirtualRange m_range;
size_t m_offset_in_vmobject { 0 };
LockRefPtr<VMObject> m_vmobject;
OwnPtr<KString> m_name;
Atomic<u32> m_in_progress_page_faults;
u8 m_access { Region::None };
bool m_shared : 1 { false };
bool m_cacheable : 1 { false };
bool m_stack : 1 { false };
bool m_mmap : 1 { false };
bool m_immutable : 1 { false };
bool m_syscall_region : 1 { false };
bool m_write_combine : 1 { false };
bool m_mmapped_from_readable : 1 { false };
bool m_mmapped_from_writable : 1 { false };
IntrusiveRedBlackTreeNode<FlatPtr, Region, RawPtr<Region>> m_tree_node;
IntrusiveListNode<Region> m_vmobject_list_node;
public:
using ListInVMObject = IntrusiveList<&Region::m_vmobject_list_node>;
};
AK_ENUM_BITWISE_OPERATORS(Region::Access)
constexpr Region::Access prot_to_region_access_flags(int prot)
{
Region::Access access = Region::Access::None;
if ((prot & PROT_READ) == PROT_READ)
access |= Region::Access::Read;
if ((prot & PROT_WRITE) == PROT_WRITE)
access |= Region::Access::Write;
if ((prot & PROT_EXEC) == PROT_EXEC)
access |= Region::Access::Execute;
return access;
}
constexpr int region_access_flags_to_prot(Region::Access access)
{
int prot = 0;
if ((access & Region::Access::Read) == Region::Access::Read)
prot |= PROT_READ;
if ((access & Region::Access::Write) == Region::Access::Write)
prot |= PROT_WRITE;
if ((access & Region::Access::Execute) == Region::Access::Execute)
prot |= PROT_EXEC;
return prot;
}
}