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- #include "CMOS.h"
- #include "Process.h"
- #include "StdLib.h"
- #include <AK/Assertions.h>
- #include <AK/kstdio.h>
- #include <Kernel/Arch/i386/CPU.h>
- #include <Kernel/FileSystem/Inode.h>
- #include <Kernel/Multiboot.h>
- #include <Kernel/VM/MemoryManager.h>
- //#define MM_DEBUG
- //#define PAGE_FAULT_DEBUG
- static MemoryManager* s_the;
- MemoryManager& MM
- {
- return *s_the;
- }
- MemoryManager::MemoryManager()
- {
- m_kernel_page_directory = PageDirectory::create_at_fixed_address(PhysicalAddress(0x4000));
- m_page_table_zero = (PageTableEntry*)0x6000;
- m_page_table_one = (PageTableEntry*)0x7000;
- initialize_paging();
- kprintf("MM initialized.\n");
- }
- MemoryManager::~MemoryManager()
- {
- }
- void MemoryManager::populate_page_directory(PageDirectory& page_directory)
- {
- page_directory.m_directory_page = allocate_supervisor_physical_page();
- page_directory.entries()[0].copy_from({}, kernel_page_directory().entries()[0]);
- page_directory.entries()[1].copy_from({}, kernel_page_directory().entries()[1]);
- // Defer to the kernel page tables for 0xC0000000-0xFFFFFFFF
- for (int i = 768; i < 1024; ++i)
- page_directory.entries()[i].copy_from({}, kernel_page_directory().entries()[i]);
- }
- void MemoryManager::initialize_paging()
- {
- memset(m_page_table_zero, 0, PAGE_SIZE);
- memset(m_page_table_one, 0, PAGE_SIZE);
- #ifdef MM_DEBUG
- dbgprintf("MM: Kernel page directory @ %p\n", kernel_page_directory().cr3());
- #endif
- #ifdef MM_DEBUG
- dbgprintf("MM: Protect against null dereferences\n");
- #endif
- // Make null dereferences crash.
- map_protected(VirtualAddress(0), PAGE_SIZE);
- #ifdef MM_DEBUG
- dbgprintf("MM: Identity map bottom 5MB\n");
- #endif
- // The bottom 5 MB (except for the null page) are identity mapped & supervisor only.
- // Every process shares these mappings.
- create_identity_mapping(kernel_page_directory(), VirtualAddress(PAGE_SIZE), (5 * MB) - PAGE_SIZE);
- // Basic memory map:
- // 0 -> 512 kB Kernel code. Root page directory & PDE 0.
- // (last page before 1MB) Used by quickmap_page().
- // 1 MB -> 3 MB kmalloc_eternal() space.
- // 3 MB -> 4 MB kmalloc() space.
- // 4 MB -> 5 MB Supervisor physical pages (available for allocation!)
- // 5 MB -> 0xc0000000 Userspace physical pages (available for allocation!)
- // 0xc0000000-0xffffffff Kernel-only virtual address space
- #ifdef MM_DEBUG
- dbgprintf("MM: Quickmap will use %p\n", m_quickmap_addr.get());
- #endif
- m_quickmap_addr = VirtualAddress((1 * MB) - PAGE_SIZE);
- RefPtr<PhysicalRegion> region;
- bool region_is_super = false;
- for (auto* mmap = (multiboot_memory_map_t*)multiboot_info_ptr->mmap_addr; (unsigned long)mmap < multiboot_info_ptr->mmap_addr + multiboot_info_ptr->mmap_length; mmap = (multiboot_memory_map_t*)((unsigned long)mmap + mmap->size + sizeof(mmap->size))) {
- kprintf("MM: Multiboot mmap: base_addr = 0x%x%08x, length = 0x%x%08x, type = 0x%x\n",
- (dword)(mmap->addr >> 32),
- (dword)(mmap->addr & 0xffffffff),
- (dword)(mmap->len >> 32),
- (dword)(mmap->len & 0xffffffff),
- (dword)mmap->type);
- if (mmap->type != MULTIBOOT_MEMORY_AVAILABLE)
- continue;
- // FIXME: Maybe make use of stuff below the 1MB mark?
- if (mmap->addr < (1 * MB))
- continue;
- #ifdef MM_DEBUG
- kprintf("MM: considering memory at %p - %p\n",
- (dword)mmap->addr, (dword)(mmap->addr + mmap->len));
- #endif
- for (size_t page_base = mmap->addr; page_base < (mmap->addr + mmap->len); page_base += PAGE_SIZE) {
- auto addr = PhysicalAddress(page_base);
- if (page_base < 4 * MB) {
- // nothing
- } else if (page_base >= 4 * MB && page_base < 5 * MB) {
- if (region.is_null() || !region_is_super || region->upper().offset(PAGE_SIZE) != addr) {
- m_super_physical_regions.append(PhysicalRegion::create(addr, addr));
- region = m_super_physical_regions.last();
- region_is_super = true;
- } else {
- region->expand(region->lower(), addr);
- }
- } else {
- if (region.is_null() || region_is_super || region->upper().offset(PAGE_SIZE) != addr) {
- m_user_physical_regions.append(PhysicalRegion::create(addr, addr));
- region = &m_user_physical_regions.last();
- region_is_super = false;
- } else {
- region->expand(region->lower(), addr);
- }
- }
- }
- }
- for (auto& region : m_super_physical_regions)
- m_super_physical_pages += region.finalize_capacity();
- for (auto& region : m_user_physical_regions)
- m_user_physical_pages += region.finalize_capacity();
- #ifdef MM_DEBUG
- dbgprintf("MM: Installing page directory\n");
- #endif
- asm volatile("movl %%eax, %%cr3" ::"a"(kernel_page_directory().cr3()));
- asm volatile(
- "movl %%cr0, %%eax\n"
- "orl $0x80000001, %%eax\n"
- "movl %%eax, %%cr0\n" ::
- : "%eax", "memory");
- #ifdef MM_DEBUG
- dbgprintf("MM: Paging initialized.\n");
- #endif
- }
- RefPtr<PhysicalPage> MemoryManager::allocate_page_table(PageDirectory& page_directory, unsigned index)
- {
- ASSERT(!page_directory.m_physical_pages.contains(index));
- auto physical_page = allocate_supervisor_physical_page();
- if (!physical_page)
- return nullptr;
- page_directory.m_physical_pages.set(index, physical_page.copy_ref());
- return physical_page;
- }
- void MemoryManager::remove_identity_mapping(PageDirectory& page_directory, VirtualAddress vaddr, size_t size)
- {
- InterruptDisabler disabler;
- // FIXME: ASSERT(vaddr is 4KB aligned);
- for (dword offset = 0; offset < size; offset += PAGE_SIZE) {
- auto pte_address = vaddr.offset(offset);
- auto& pte = ensure_pte(page_directory, pte_address);
- pte.set_physical_page_base(0);
- pte.set_user_allowed(false);
- pte.set_present(true);
- pte.set_writable(true);
- flush_tlb(pte_address);
- }
- }
- PageTableEntry& MemoryManager::ensure_pte(PageDirectory& page_directory, VirtualAddress vaddr)
- {
- ASSERT_INTERRUPTS_DISABLED();
- dword page_directory_index = (vaddr.get() >> 22) & 0x3ff;
- dword page_table_index = (vaddr.get() >> 12) & 0x3ff;
- PageDirectoryEntry& pde = page_directory.entries()[page_directory_index];
- if (!pde.is_present()) {
- #ifdef MM_DEBUG
- dbgprintf("MM: PDE %u not present (requested for L%x), allocating\n", page_directory_index, vaddr.get());
- #endif
- if (page_directory_index == 0) {
- ASSERT(&page_directory == m_kernel_page_directory);
- pde.set_page_table_base((dword)m_page_table_zero);
- pde.set_user_allowed(false);
- pde.set_present(true);
- pde.set_writable(true);
- } else if (page_directory_index == 1) {
- ASSERT(&page_directory == m_kernel_page_directory);
- pde.set_page_table_base((dword)m_page_table_one);
- pde.set_user_allowed(false);
- pde.set_present(true);
- pde.set_writable(true);
- } else {
- //ASSERT(&page_directory != m_kernel_page_directory.ptr());
- auto page_table = allocate_page_table(page_directory, page_directory_index);
- #ifdef MM_DEBUG
- dbgprintf("MM: PD K%x (%s) at P%x allocated page table #%u (for L%x) at P%x\n",
- &page_directory,
- &page_directory == m_kernel_page_directory ? "Kernel" : "User",
- page_directory.cr3(),
- page_directory_index,
- vaddr.get(),
- page_table->paddr().get());
- #endif
- pde.set_page_table_base(page_table->paddr().get());
- pde.set_user_allowed(true);
- pde.set_present(true);
- pde.set_writable(true);
- page_directory.m_physical_pages.set(page_directory_index, move(page_table));
- }
- }
- return pde.page_table_base()[page_table_index];
- }
- void MemoryManager::map_protected(VirtualAddress vaddr, size_t length)
- {
- InterruptDisabler disabler;
- ASSERT(vaddr.is_page_aligned());
- for (dword offset = 0; offset < length; offset += PAGE_SIZE) {
- auto pte_address = vaddr.offset(offset);
- auto& pte = ensure_pte(kernel_page_directory(), pte_address);
- pte.set_physical_page_base(pte_address.get());
- pte.set_user_allowed(false);
- pte.set_present(false);
- pte.set_writable(false);
- flush_tlb(pte_address);
- }
- }
- void MemoryManager::create_identity_mapping(PageDirectory& page_directory, VirtualAddress vaddr, size_t size)
- {
- InterruptDisabler disabler;
- ASSERT((vaddr.get() & ~PAGE_MASK) == 0);
- for (dword offset = 0; offset < size; offset += PAGE_SIZE) {
- auto pte_address = vaddr.offset(offset);
- auto& pte = ensure_pte(page_directory, pte_address);
- pte.set_physical_page_base(pte_address.get());
- pte.set_user_allowed(false);
- pte.set_present(true);
- pte.set_writable(true);
- page_directory.flush(pte_address);
- }
- }
- void MemoryManager::initialize()
- {
- s_the = new MemoryManager;
- }
- Region* MemoryManager::region_from_vaddr(Process& process, VirtualAddress vaddr)
- {
- ASSERT_INTERRUPTS_DISABLED();
- if (vaddr.get() >= 0xc0000000) {
- for (auto& region : MM.m_kernel_regions) {
- if (region->contains(vaddr))
- return region;
- }
- }
- // FIXME: Use a binary search tree (maybe red/black?) or some other more appropriate data structure!
- for (auto& region : process.m_regions) {
- if (region.contains(vaddr))
- return ®ion;
- }
- dbgprintf("%s(%u) Couldn't find region for L%x (CR3=%x)\n", process.name().characters(), process.pid(), vaddr.get(), process.page_directory().cr3());
- return nullptr;
- }
- const Region* MemoryManager::region_from_vaddr(const Process& process, VirtualAddress vaddr)
- {
- if (vaddr.get() >= 0xc0000000) {
- for (auto& region : MM.m_kernel_regions) {
- if (region->contains(vaddr))
- return region;
- }
- }
- // FIXME: Use a binary search tree (maybe red/black?) or some other more appropriate data structure!
- for (auto& region : process.m_regions) {
- if (region.contains(vaddr))
- return ®ion;
- }
- dbgprintf("%s(%u) Couldn't find region for L%x (CR3=%x)\n", process.name().characters(), process.pid(), vaddr.get(), process.page_directory().cr3());
- return nullptr;
- }
- bool MemoryManager::zero_page(Region& region, unsigned page_index_in_region)
- {
- ASSERT_INTERRUPTS_DISABLED();
- auto& vmo = region.vmo();
- auto& vmo_page = vmo.physical_pages()[region.first_page_index() + page_index_in_region];
- sti();
- LOCKER(vmo.m_paging_lock);
- cli();
- if (!vmo_page.is_null()) {
- #ifdef PAGE_FAULT_DEBUG
- dbgprintf("MM: zero_page() but page already present. Fine with me!\n");
- #endif
- remap_region_page(region, page_index_in_region, true);
- return true;
- }
- auto physical_page = allocate_user_physical_page(ShouldZeroFill::Yes);
- #ifdef PAGE_FAULT_DEBUG
- dbgprintf(" >> ZERO P%x\n", physical_page->paddr().get());
- #endif
- region.set_should_cow(page_index_in_region, false);
- vmo.physical_pages()[page_index_in_region] = move(physical_page);
- remap_region_page(region, page_index_in_region, true);
- return true;
- }
- bool MemoryManager::copy_on_write(Region& region, unsigned page_index_in_region)
- {
- ASSERT_INTERRUPTS_DISABLED();
- auto& vmo = region.vmo();
- if (vmo.physical_pages()[page_index_in_region]->ref_count() == 1) {
- #ifdef PAGE_FAULT_DEBUG
- dbgprintf(" >> It's a COW page but nobody is sharing it anymore. Remap r/w\n");
- #endif
- region.set_should_cow(page_index_in_region, false);
- remap_region_page(region, page_index_in_region, true);
- return true;
- }
- #ifdef PAGE_FAULT_DEBUG
- dbgprintf(" >> It's a COW page and it's time to COW!\n");
- #endif
- auto physical_page_to_copy = move(vmo.physical_pages()[page_index_in_region]);
- auto physical_page = allocate_user_physical_page(ShouldZeroFill::No);
- byte* dest_ptr = quickmap_page(*physical_page);
- const byte* src_ptr = region.vaddr().offset(page_index_in_region * PAGE_SIZE).as_ptr();
- #ifdef PAGE_FAULT_DEBUG
- dbgprintf(" >> COW P%x <- P%x\n", physical_page->paddr().get(), physical_page_to_copy->paddr().get());
- #endif
- memcpy(dest_ptr, src_ptr, PAGE_SIZE);
- vmo.physical_pages()[page_index_in_region] = move(physical_page);
- unquickmap_page();
- region.set_should_cow(page_index_in_region, false);
- remap_region_page(region, page_index_in_region, true);
- return true;
- }
- bool MemoryManager::page_in_from_inode(Region& region, unsigned page_index_in_region)
- {
- ASSERT(region.page_directory());
- auto& vmo = region.vmo();
- ASSERT(!vmo.is_anonymous());
- ASSERT(vmo.inode());
- auto& vmo_page = vmo.physical_pages()[region.first_page_index() + page_index_in_region];
- InterruptFlagSaver saver;
- sti();
- LOCKER(vmo.m_paging_lock);
- cli();
- if (!vmo_page.is_null()) {
- dbgprintf("MM: page_in_from_inode() but page already present. Fine with me!\n");
- remap_region_page(region, page_index_in_region, true);
- return true;
- }
- #ifdef MM_DEBUG
- dbgprintf("MM: page_in_from_inode ready to read from inode\n");
- #endif
- sti();
- byte page_buffer[PAGE_SIZE];
- auto& inode = *vmo.inode();
- auto nread = inode.read_bytes(vmo.inode_offset() + ((region.first_page_index() + page_index_in_region) * PAGE_SIZE), PAGE_SIZE, page_buffer, nullptr);
- if (nread < 0) {
- kprintf("MM: page_in_from_inode had error (%d) while reading!\n", nread);
- return false;
- }
- if (nread < PAGE_SIZE) {
- // If we read less than a page, zero out the rest to avoid leaking uninitialized data.
- memset(page_buffer + nread, 0, PAGE_SIZE - nread);
- }
- cli();
- vmo_page = allocate_user_physical_page(ShouldZeroFill::No);
- if (vmo_page.is_null()) {
- kprintf("MM: page_in_from_inode was unable to allocate a physical page\n");
- return false;
- }
- remap_region_page(region, page_index_in_region, true);
- byte* dest_ptr = region.vaddr().offset(page_index_in_region * PAGE_SIZE).as_ptr();
- memcpy(dest_ptr, page_buffer, PAGE_SIZE);
- return true;
- }
- PageFaultResponse MemoryManager::handle_page_fault(const PageFault& fault)
- {
- ASSERT_INTERRUPTS_DISABLED();
- ASSERT(current);
- #ifdef PAGE_FAULT_DEBUG
- dbgprintf("MM: handle_page_fault(%w) at L%x\n", fault.code(), fault.vaddr().get());
- #endif
- ASSERT(fault.vaddr() != m_quickmap_addr);
- if (fault.is_not_present() && fault.vaddr().get() >= 0xc0000000) {
- dword page_directory_index = (fault.vaddr().get() >> 22) & 0x3ff;
- if (kernel_page_directory().entries()[page_directory_index].is_present()) {
- current->process().page_directory().entries()[page_directory_index].copy_from({}, kernel_page_directory().entries()[page_directory_index]);
- dbgprintf("NP(kernel): copying new kernel mapping for L%x into process\n", fault.vaddr().get());
- return PageFaultResponse::Continue;
- }
- }
- auto* region = region_from_vaddr(current->process(), fault.vaddr());
- if (!region) {
- kprintf("NP(error) fault at invalid address L%x\n", fault.vaddr().get());
- return PageFaultResponse::ShouldCrash;
- }
- auto page_index_in_region = region->page_index_from_address(fault.vaddr());
- if (fault.is_not_present()) {
- if (region->vmo().inode()) {
- #ifdef PAGE_FAULT_DEBUG
- dbgprintf("NP(inode) fault in Region{%p}[%u]\n", region, page_index_in_region);
- #endif
- page_in_from_inode(*region, page_index_in_region);
- return PageFaultResponse::Continue;
- } else {
- #ifdef PAGE_FAULT_DEBUG
- dbgprintf("NP(zero) fault in Region{%p}[%u]\n", region, page_index_in_region);
- #endif
- zero_page(*region, page_index_in_region);
- return PageFaultResponse::Continue;
- }
- } else if (fault.is_protection_violation()) {
- if (region->should_cow(page_index_in_region)) {
- #ifdef PAGE_FAULT_DEBUG
- dbgprintf("PV(cow) fault in Region{%p}[%u]\n", region, page_index_in_region);
- #endif
- bool success = copy_on_write(*region, page_index_in_region);
- ASSERT(success);
- return PageFaultResponse::Continue;
- }
- kprintf("PV(error) fault in Region{%p}[%u] at L%x\n", region, page_index_in_region, fault.vaddr().get());
- } else {
- ASSERT_NOT_REACHED();
- }
- return PageFaultResponse::ShouldCrash;
- }
- RefPtr<Region> MemoryManager::allocate_kernel_region(size_t size, String&& name)
- {
- InterruptDisabler disabler;
- ASSERT(!(size % PAGE_SIZE));
- auto range = kernel_page_directory().range_allocator().allocate_anywhere(size);
- ASSERT(range.is_valid());
- auto region = adopt(*new Region(range, move(name), PROT_READ | PROT_WRITE | PROT_EXEC, false));
- MM.map_region_at_address(*m_kernel_page_directory, *region, range.base(), false);
- // FIXME: It would be cool if these could zero-fill on demand instead.
- region->commit();
- return region;
- }
- void MemoryManager::deallocate_user_physical_page(PhysicalPage&& page)
- {
- for (auto& region : m_user_physical_regions) {
- if (!region.contains(page)) {
- kprintf(
- "MM: deallocate_user_physical_page: %p not in %p -> %p\n",
- page.paddr(), region.lower().get(), region.upper().get());
- continue;
- }
- region.return_page(move(page));
- --m_user_physical_pages_used;
- return;
- }
- kprintf("MM: deallocate_user_physical_page couldn't figure out region for user page @ %p\n", page.paddr());
- ASSERT_NOT_REACHED();
- }
- RefPtr<PhysicalPage> MemoryManager::allocate_user_physical_page(ShouldZeroFill should_zero_fill)
- {
- InterruptDisabler disabler;
- RefPtr<PhysicalPage> page;
- for (auto& region : m_user_physical_regions) {
- page = region.take_free_page(false);
- if (page.is_null())
- continue;
- }
- if (!page) {
- if (m_user_physical_regions.is_empty()) {
- kprintf("MM: no user physical regions available (?)\n");
- }
- kprintf("MM: no user physical pages available\n");
- ASSERT_NOT_REACHED();
- return {};
- }
- #ifdef MM_DEBUG
- dbgprintf("MM: allocate_user_physical_page vending P%p\n", page->paddr().get());
- #endif
- if (should_zero_fill == ShouldZeroFill::Yes) {
- auto* ptr = (dword*)quickmap_page(*page);
- fast_dword_fill(ptr, 0, PAGE_SIZE / sizeof(dword));
- unquickmap_page();
- }
- ++m_user_physical_pages_used;
- return page;
- }
- void MemoryManager::deallocate_supervisor_physical_page(PhysicalPage&& page)
- {
- for (auto& region : m_super_physical_regions) {
- if (!region.contains(page)) {
- kprintf(
- "MM: deallocate_supervisor_physical_page: %p not in %p -> %p\n",
- page.paddr(), region.lower().get(), region.upper().get());
- continue;
- }
- region.return_page(move(page));
- --m_super_physical_pages_used;
- return;
- }
- kprintf("MM: deallocate_supervisor_physical_page couldn't figure out region for super page @ %p\n", page.paddr());
- ASSERT_NOT_REACHED();
- }
- RefPtr<PhysicalPage> MemoryManager::allocate_supervisor_physical_page()
- {
- InterruptDisabler disabler;
- RefPtr<PhysicalPage> page;
- for (auto& region : m_super_physical_regions) {
- page = region.take_free_page(true);
- if (page.is_null())
- continue;
- }
- if (!page) {
- if (m_super_physical_regions.is_empty()) {
- kprintf("MM: no super physical regions available (?)\n");
- }
- kprintf("MM: no super physical pages available\n");
- ASSERT_NOT_REACHED();
- return {};
- }
- #ifdef MM_DEBUG
- dbgprintf("MM: allocate_supervisor_physical_page vending P%p\n", page->paddr().get());
- #endif
- fast_dword_fill((dword*)page->paddr().as_ptr(), 0, PAGE_SIZE / sizeof(dword));
- ++m_super_physical_pages_used;
- return page;
- }
- void MemoryManager::enter_process_paging_scope(Process& process)
- {
- ASSERT(current);
- InterruptDisabler disabler;
- current->tss().cr3 = process.page_directory().cr3();
- asm volatile("movl %%eax, %%cr3" ::"a"(process.page_directory().cr3())
- : "memory");
- }
- void MemoryManager::flush_entire_tlb()
- {
- asm volatile(
- "mov %%cr3, %%eax\n"
- "mov %%eax, %%cr3\n" ::
- : "%eax", "memory");
- }
- void MemoryManager::flush_tlb(VirtualAddress vaddr)
- {
- asm volatile("invlpg %0"
- :
- : "m"(*(char*)vaddr.get())
- : "memory");
- }
- void MemoryManager::map_for_kernel(VirtualAddress vaddr, PhysicalAddress paddr)
- {
- auto& pte = ensure_pte(kernel_page_directory(), vaddr);
- pte.set_physical_page_base(paddr.get());
- pte.set_present(true);
- pte.set_writable(true);
- pte.set_user_allowed(false);
- flush_tlb(vaddr);
- }
- byte* MemoryManager::quickmap_page(PhysicalPage& physical_page)
- {
- ASSERT_INTERRUPTS_DISABLED();
- ASSERT(!m_quickmap_in_use);
- m_quickmap_in_use = true;
- auto page_vaddr = m_quickmap_addr;
- auto& pte = ensure_pte(kernel_page_directory(), page_vaddr);
- pte.set_physical_page_base(physical_page.paddr().get());
- pte.set_present(true);
- pte.set_writable(true);
- pte.set_user_allowed(false);
- flush_tlb(page_vaddr);
- ASSERT((dword)pte.physical_page_base() == physical_page.paddr().get());
- #ifdef MM_DEBUG
- dbgprintf("MM: >> quickmap_page L%x => P%x @ PTE=%p\n", page_vaddr, physical_page.paddr().get(), pte.ptr());
- #endif
- return page_vaddr.as_ptr();
- }
- void MemoryManager::unquickmap_page()
- {
- ASSERT_INTERRUPTS_DISABLED();
- ASSERT(m_quickmap_in_use);
- auto page_vaddr = m_quickmap_addr;
- auto& pte = ensure_pte(kernel_page_directory(), page_vaddr);
- #ifdef MM_DEBUG
- auto old_physical_address = pte.physical_page_base();
- #endif
- pte.set_physical_page_base(0);
- pte.set_present(false);
- pte.set_writable(false);
- flush_tlb(page_vaddr);
- #ifdef MM_DEBUG
- dbgprintf("MM: >> unquickmap_page L%x =/> P%x\n", page_vaddr, old_physical_address);
- #endif
- m_quickmap_in_use = false;
- }
- void MemoryManager::remap_region_page(Region& region, unsigned page_index_in_region, bool user_allowed)
- {
- ASSERT(region.page_directory());
- InterruptDisabler disabler;
- auto page_vaddr = region.vaddr().offset(page_index_in_region * PAGE_SIZE);
- auto& pte = ensure_pte(*region.page_directory(), page_vaddr);
- auto& physical_page = region.vmo().physical_pages()[page_index_in_region];
- ASSERT(physical_page);
- pte.set_physical_page_base(physical_page->paddr().get());
- pte.set_present(true); // FIXME: Maybe we should use the is_readable flag here?
- if (region.should_cow(page_index_in_region))
- pte.set_writable(false);
- else
- pte.set_writable(region.is_writable());
- pte.set_cache_disabled(!region.vmo().m_allow_cpu_caching);
- pte.set_write_through(!region.vmo().m_allow_cpu_caching);
- pte.set_user_allowed(user_allowed);
- region.page_directory()->flush(page_vaddr);
- #ifdef MM_DEBUG
- dbgprintf("MM: >> remap_region_page (PD=%x, PTE=P%x) '%s' L%x => P%x (@%p)\n", region.page_directory()->cr3(), pte.ptr(), region.name().characters(), page_vaddr.get(), physical_page->paddr().get(), physical_page.ptr());
- #endif
- }
- void MemoryManager::remap_region(PageDirectory& page_directory, Region& region)
- {
- InterruptDisabler disabler;
- ASSERT(region.page_directory() == &page_directory);
- map_region_at_address(page_directory, region, region.vaddr(), true);
- }
- void MemoryManager::map_region_at_address(PageDirectory& page_directory, Region& region, VirtualAddress vaddr, bool user_allowed)
- {
- InterruptDisabler disabler;
- region.set_page_directory(page_directory);
- auto& vmo = region.vmo();
- #ifdef MM_DEBUG
- dbgprintf("MM: map_region_at_address will map VMO pages %u - %u (VMO page count: %u)\n", region.first_page_index(), region.last_page_index(), vmo.page_count());
- #endif
- for (size_t i = 0; i < region.page_count(); ++i) {
- auto page_vaddr = vaddr.offset(i * PAGE_SIZE);
- auto& pte = ensure_pte(page_directory, page_vaddr);
- auto& physical_page = vmo.physical_pages()[region.first_page_index() + i];
- if (physical_page) {
- pte.set_physical_page_base(physical_page->paddr().get());
- pte.set_present(true); // FIXME: Maybe we should use the is_readable flag here?
- // FIXME: It seems wrong that the *region* cow map is essentially using *VMO* relative indices.
- if (region.should_cow(region.first_page_index() + i))
- pte.set_writable(false);
- else
- pte.set_writable(region.is_writable());
- pte.set_cache_disabled(!region.vmo().m_allow_cpu_caching);
- pte.set_write_through(!region.vmo().m_allow_cpu_caching);
- } else {
- pte.set_physical_page_base(0);
- pte.set_present(false);
- pte.set_writable(region.is_writable());
- }
- pte.set_user_allowed(user_allowed);
- page_directory.flush(page_vaddr);
- #ifdef MM_DEBUG
- dbgprintf("MM: >> map_region_at_address (PD=%x) '%s' L%x => P%x (@%p)\n", &page_directory, region.name().characters(), page_vaddr, physical_page ? physical_page->paddr().get() : 0, physical_page.ptr());
- #endif
- }
- }
- bool MemoryManager::unmap_region(Region& region)
- {
- ASSERT(region.page_directory());
- InterruptDisabler disabler;
- for (size_t i = 0; i < region.page_count(); ++i) {
- auto vaddr = region.vaddr().offset(i * PAGE_SIZE);
- auto& pte = ensure_pte(*region.page_directory(), vaddr);
- pte.set_physical_page_base(0);
- pte.set_present(false);
- pte.set_writable(false);
- pte.set_user_allowed(false);
- region.page_directory()->flush(vaddr);
- #ifdef MM_DEBUG
- auto& physical_page = region.vmo().physical_pages()[region.first_page_index() + i];
- dbgprintf("MM: >> Unmapped L%x => P%x <<\n", vaddr, physical_page ? physical_page->paddr().get() : 0);
- #endif
- }
- region.release_page_directory();
- return true;
- }
- bool MemoryManager::map_region(Process& process, Region& region)
- {
- map_region_at_address(process.page_directory(), region, region.vaddr(), true);
- return true;
- }
- bool MemoryManager::validate_user_read(const Process& process, VirtualAddress vaddr) const
- {
- auto* region = region_from_vaddr(process, vaddr);
- return region && region->is_readable();
- }
- bool MemoryManager::validate_user_write(const Process& process, VirtualAddress vaddr) const
- {
- auto* region = region_from_vaddr(process, vaddr);
- return region && region->is_writable();
- }
- void MemoryManager::register_vmo(VMObject& vmo)
- {
- InterruptDisabler disabler;
- m_vmos.set(&vmo);
- }
- void MemoryManager::unregister_vmo(VMObject& vmo)
- {
- InterruptDisabler disabler;
- m_vmos.remove(&vmo);
- }
- void MemoryManager::register_region(Region& region)
- {
- InterruptDisabler disabler;
- if (region.vaddr().get() >= 0xc0000000)
- m_kernel_regions.set(®ion);
- else
- m_user_regions.set(®ion);
- }
- void MemoryManager::unregister_region(Region& region)
- {
- InterruptDisabler disabler;
- if (region.vaddr().get() >= 0xc0000000)
- m_kernel_regions.remove(®ion);
- else
- m_user_regions.remove(®ion);
- }
- ProcessPagingScope::ProcessPagingScope(Process& process)
- {
- ASSERT(current);
- MM.enter_process_paging_scope(process);
- }
- ProcessPagingScope::~ProcessPagingScope()
- {
- MM.enter_process_paging_scope(current->process());
- }
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