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	 d89582880e
			
		
	
	
		d89582880e
		
	
	
	
	
		
			
			MemoryManager cannot use the Singleton class because MemoryManager::initialize is called before the global constructors are run. That caused the Singleton to be re-initialized, causing it to create another MemoryManager instance. Fixes #3226
		
			
				
	
	
		
			124 lines
		
	
	
	
		
			5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			124 lines
		
	
	
	
		
			5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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|  * All rights reserved.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions are met:
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|  *
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|  * 1. Redistributions of source code must retain the above copyright notice, this
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|  *    list of conditions and the following disclaimer.
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|  *
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|  * 2. Redistributions in binary form must reproduce the above copyright notice,
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|  *    this list of conditions and the following disclaimer in the documentation
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|  *    and/or other materials provided with the distribution.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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|  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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|  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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|  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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|  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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|  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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|  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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|  */
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| 
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| #include <AK/Memory.h>
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| #include <AK/Singleton.h>
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| #include <Kernel/Process.h>
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| #include <Kernel/Random.h>
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| #include <Kernel/Thread.h>
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| #include <Kernel/VM/MemoryManager.h>
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| #include <Kernel/VM/PageDirectory.h>
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| 
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| namespace Kernel {
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| 
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| static const FlatPtr userspace_range_base = 0x00800000;
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| static const FlatPtr userspace_range_ceiling = 0xbe000000;
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| static const FlatPtr kernelspace_range_base = 0xc0800000;
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| 
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| static AK::Singleton<HashMap<u32, PageDirectory*>> s_cr3_map;
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| 
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| static HashMap<u32, PageDirectory*>& cr3_map()
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| {
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|     ASSERT_INTERRUPTS_DISABLED();
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|     return *s_cr3_map;
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| }
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| 
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| RefPtr<PageDirectory> PageDirectory::find_by_cr3(u32 cr3)
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| {
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|     ScopedSpinLock lock(s_mm_lock);
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|     return cr3_map().get(cr3).value_or({});
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| }
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| 
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| extern "C" PageDirectoryEntry* boot_pdpt[4];
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| extern "C" PageDirectoryEntry boot_pd0[1024];
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| extern "C" PageDirectoryEntry boot_pd3[1024];
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| 
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| PageDirectory::PageDirectory()
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| {
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|     m_range_allocator.initialize_with_range(VirtualAddress(0xc0800000), 0x3f000000);
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|     m_identity_range_allocator.initialize_with_range(VirtualAddress(FlatPtr(0x00000000)), 0x00200000);
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| 
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|     // Adopt the page tables already set up by boot.S
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|     PhysicalAddress boot_pdpt_paddr(virtual_to_low_physical((FlatPtr)boot_pdpt));
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|     PhysicalAddress boot_pd0_paddr(virtual_to_low_physical((FlatPtr)boot_pd0));
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|     PhysicalAddress boot_pd3_paddr(virtual_to_low_physical((FlatPtr)boot_pd3));
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|     klog() << "MM: boot_pdpt @ " << boot_pdpt_paddr;
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|     klog() << "MM: boot_pd0 @ " << boot_pd0_paddr;
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|     klog() << "MM: boot_pd3 @ " << boot_pd3_paddr;
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|     m_directory_table = PhysicalPage::create(boot_pdpt_paddr, true, false);
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|     m_directory_pages[0] = PhysicalPage::create(boot_pd0_paddr, true, false);
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|     m_directory_pages[3] = PhysicalPage::create(boot_pd3_paddr, true, false);
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| }
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| 
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| PageDirectory::PageDirectory(Process& process, const RangeAllocator* parent_range_allocator)
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|     : m_process(&process)
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| {
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|     ScopedSpinLock lock(s_mm_lock);
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|     if (parent_range_allocator) {
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|         m_range_allocator.initialize_from_parent(*parent_range_allocator);
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|     } else {
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|         size_t random_offset = (get_fast_random<u8>() % 32 * MiB) & PAGE_MASK;
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|         u32 base = userspace_range_base + random_offset;
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|         m_range_allocator.initialize_with_range(VirtualAddress(base), userspace_range_ceiling - base);
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|     }
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| 
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|     // Set up a userspace page directory
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|     m_directory_table = MM.allocate_user_physical_page();
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|     m_directory_pages[0] = MM.allocate_user_physical_page();
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|     m_directory_pages[1] = MM.allocate_user_physical_page();
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|     m_directory_pages[2] = MM.allocate_user_physical_page();
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|     // Share the top 1 GiB of kernel-only mappings (>=3GiB or >=0xc0000000)
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|     m_directory_pages[3] = MM.kernel_page_directory().m_directory_pages[3];
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| 
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|     {
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|         auto& table = *(PageDirectoryPointerTable*)MM.quickmap_page(*m_directory_table);
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|         table.raw[0] = (u64)m_directory_pages[0]->paddr().as_ptr() | 1;
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|         table.raw[1] = (u64)m_directory_pages[1]->paddr().as_ptr() | 1;
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|         table.raw[2] = (u64)m_directory_pages[2]->paddr().as_ptr() | 1;
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|         table.raw[3] = (u64)m_directory_pages[3]->paddr().as_ptr() | 1;
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|         MM.unquickmap_page();
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|     }
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| 
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|     // Clone bottom 2 MiB of mappings from kernel_page_directory
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|     PageDirectoryEntry buffer;
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|     auto* kernel_pd = MM.quickmap_pd(MM.kernel_page_directory(), 0);
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|     memcpy(&buffer, kernel_pd, sizeof(PageDirectoryEntry));
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|     auto* new_pd = MM.quickmap_pd(*this, 0);
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|     memcpy(new_pd, &buffer, sizeof(PageDirectoryEntry));
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| 
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|     cr3_map().set(cr3(), this);
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| }
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| 
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| PageDirectory::~PageDirectory()
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| {
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| #ifdef MM_DEBUG
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|     dbg() << "MM: ~PageDirectory K" << this;
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| #endif
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|     ScopedSpinLock lock(s_mm_lock);
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|     cr3_map().remove(cr3());
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| }
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| 
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| }
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