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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/InlineLinkedList.h>
#include <AK/String.h>
#include <AK/Weakable.h>
#include <Kernel/Arch/i386/CPU.h>
#include <Kernel/Heap/SlabAllocator.h>
#include <Kernel/VM/RangeAllocator.h>
#include <Kernel/VM/VMObject.h>
namespace Kernel {
class Inode;
class VMObject;
enum class PageFaultResponse {
ShouldCrash,
OutOfMemory,
Continue,
};
class Region final
: public InlineLinkedListNode<Region>
, public Weakable<Region> {
friend class MemoryManager;
MAKE_SLAB_ALLOCATED(Region)
public:
enum Access {
Read = 1,
Write = 2,
Execute = 4,
};
enum class InheritMode {
Default,
ZeroedOnFork,
};
static NonnullOwnPtr<Region> create_user_accessible(const Range&, NonnullRefPtr<VMObject>, size_t offset_in_vmobject, const StringView& name, u8 access, bool cacheable = true);
static NonnullOwnPtr<Region> create_kernel_only(const Range&, NonnullRefPtr<VMObject>, size_t offset_in_vmobject, const StringView& name, u8 access, bool cacheable = true);
~Region();
const Range& range() const { return m_range; }
VirtualAddress vaddr() const { return m_range.base(); }
size_t size() const { return m_range.size(); }
bool is_readable() const { return m_access & Access::Read; }
bool is_writable() const { return m_access & Access::Write; }
bool is_executable() const { return m_access & Access::Execute; }
bool is_cacheable() const { return m_cacheable; }
const String& name() const { return m_name; }
unsigned access() const { return m_access; }
void set_name(const String& name) { m_name = name; }
const VMObject& vmobject() const { return *m_vmobject; }
VMObject& vmobject() { return *m_vmobject; }
void set_vmobject(NonnullRefPtr<VMObject>&& obj) { m_vmobject = obj; }
bool is_shared() const { return m_shared; }
void set_shared(bool shared) { m_shared = shared; }
bool is_stack() const { return m_stack; }
void set_stack(bool stack) { m_stack = stack; }
bool is_mmap() const { return m_mmap; }
void set_mmap(bool mmap) { m_mmap = mmap; }
bool is_user_accessible() const { return m_user_accessible; }
void set_user_accessible(bool b) { m_user_accessible = b; }
bool is_kernel() const { return m_kernel || vaddr().get() >= 0xc0000000; }
void set_kernel(bool kernel) { m_kernel = kernel; }
PageFaultResponse handle_fault(const PageFault&);
NonnullOwnPtr<Region> clone();
bool contains(VirtualAddress vaddr) const
{
return m_range.contains(vaddr);
}
bool contains(const Range& range) const
{
return m_range.contains(range);
}
unsigned page_index_from_address(VirtualAddress vaddr) const
{
return (vaddr - m_range.base()).get() / PAGE_SIZE;
}
size_t first_page_index() const
{
return m_offset_in_vmobject / PAGE_SIZE;
}
size_t last_page_index() const
{
return (first_page_index() + page_count()) - 1;
}
size_t page_count() const
{
return size() / PAGE_SIZE;
}
const PhysicalPage* physical_page(size_t index) const
{
ASSERT(index < page_count());
return vmobject().physical_pages()[first_page_index() + index];
}
RefPtr<PhysicalPage>& physical_page_slot(size_t index)
{
ASSERT(index < page_count());
return vmobject().physical_pages()[first_page_index() + index];
}
size_t offset_in_vmobject() const
{
return m_offset_in_vmobject;
}
bool commit();
bool commit(size_t page_index);
size_t amount_resident() const;
size_t amount_shared() const;
size_t amount_dirty() const;
bool should_cow(size_t page_index) const;
void set_should_cow(size_t page_index, bool);
u32 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 set_page_directory(PageDirectory&);
void map(PageDirectory&);
enum class ShouldDeallocateVirtualMemoryRange {
No,
Yes,
};
void unmap(ShouldDeallocateVirtualMemoryRange = ShouldDeallocateVirtualMemoryRange::Yes);
void remap();
void remap_page(size_t index);
// For InlineLinkedListNode
Region* m_next { nullptr };
Region* m_prev { nullptr };
// NOTE: These are public so we can make<> them.
Region(const Range&, NonnullRefPtr<VMObject>, size_t offset_in_vmobject, const String&, u8 access, bool cacheable, bool kernel);
void set_inherit_mode(InheritMode inherit_mode) { m_inherit_mode = inherit_mode; }
private:
Bitmap& ensure_cow_map() const;
void set_access_bit(Access access, bool b)
{
if (b)
m_access |= access;
else
m_access &= ~access;
}
PageFaultResponse handle_cow_fault(size_t page_index);
PageFaultResponse handle_inode_fault(size_t page_index);
PageFaultResponse handle_zero_fault(size_t page_index);
void map_individual_page_impl(size_t page_index);
RefPtr<PageDirectory> m_page_directory;
Range m_range;
size_t m_offset_in_vmobject { 0 };
NonnullRefPtr<VMObject> m_vmobject;
String m_name;
u8 m_access { 0 };
InheritMode m_inherit_mode : 3 { InheritMode::Default };
bool m_shared : 1 { false };
bool m_user_accessible : 1 { false };
bool m_cacheable : 1 { false };
bool m_stack : 1 { false };
bool m_mmap : 1 { false };
bool m_kernel : 1 { false };
mutable OwnPtr<Bitmap> m_cow_map;
};
}
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