diff options
Diffstat (limited to 'Kernel')
| -rw-r--r-- | Kernel/Memory/MemoryManager.cpp | 20 | ||||
| -rw-r--r-- | Kernel/Memory/MemoryManager.h | 15 | ||||
| -rw-r--r-- | Kernel/Memory/Region.cpp | 2 | ||||
| -rw-r--r-- | Kernel/init.cpp | 2 |
4 files changed, 31 insertions, 8 deletions
diff --git a/Kernel/Memory/MemoryManager.cpp b/Kernel/Memory/MemoryManager.cpp index 006038ea31..fb0a4ac410 100644 --- a/Kernel/Memory/MemoryManager.cpp +++ b/Kernel/Memory/MemoryManager.cpp @@ -106,6 +106,19 @@ UNMAP_AFTER_INIT void MemoryManager::protect_kernel_image() } } +UNMAP_AFTER_INIT void MemoryManager::unmap_prekernel() +{ + SpinlockLocker page_lock(kernel_page_directory().get_lock()); + SpinlockLocker mm_lock(s_mm_lock); + + auto start = start_of_prekernel_image.page_base().get(); + auto end = end_of_prekernel_image.page_base().get(); + + for (auto i = start; i <= end; i += PAGE_SIZE) + release_pte(kernel_page_directory(), VirtualAddress(i), i == end ? IsLastPTERelease::Yes : IsLastPTERelease::No, UnsafeIgnoreMissingPageTable::Yes); + flush_tlb(&kernel_page_directory(), VirtualAddress(start), (end - start) / PAGE_SIZE); +} + UNMAP_AFTER_INIT void MemoryManager::protect_readonly_after_init_memory() { SpinlockLocker page_lock(kernel_page_directory().get_lock()); @@ -200,7 +213,6 @@ UNMAP_AFTER_INIT void MemoryManager::parse_memory_map() // Register used memory regions that we know of. m_used_memory_ranges.ensure_capacity(4); m_used_memory_ranges.append(UsedMemoryRange { UsedMemoryRangeType::LowMemory, PhysicalAddress(0x00000000), PhysicalAddress(1 * MiB) }); - m_used_memory_ranges.append(UsedMemoryRange { UsedMemoryRangeType::Prekernel, start_of_prekernel_image, end_of_prekernel_image }); m_used_memory_ranges.append(UsedMemoryRange { UsedMemoryRangeType::Kernel, PhysicalAddress(virtual_to_low_physical((FlatPtr)start_of_kernel_image)), PhysicalAddress(page_round_up(virtual_to_low_physical((FlatPtr)end_of_kernel_image))) }); if (multiboot_flags & 0x4) { @@ -570,7 +582,7 @@ PageTableEntry* MemoryManager::ensure_pte(PageDirectory& page_directory, Virtual return &quickmap_pt(PhysicalAddress((FlatPtr)pde.page_table_base()))[page_table_index]; } -void MemoryManager::release_pte(PageDirectory& page_directory, VirtualAddress vaddr, bool is_last_release) +void MemoryManager::release_pte(PageDirectory& page_directory, VirtualAddress vaddr, IsLastPTERelease is_last_pte_release, UnsafeIgnoreMissingPageTable unsafe_ignore_missing_page_table) { VERIFY_INTERRUPTS_DISABLED(); VERIFY(s_mm_lock.is_locked_by_current_processor()); @@ -586,7 +598,7 @@ void MemoryManager::release_pte(PageDirectory& page_directory, VirtualAddress va auto& pte = page_table[page_table_index]; pte.clear(); - if (is_last_release || page_table_index == 0x1ff) { + if (is_last_pte_release == IsLastPTERelease::Yes || page_table_index == 0x1ff) { // If this is the last PTE in a region or the last PTE in a page table then // check if we can also release the page table bool all_clear = true; @@ -600,7 +612,7 @@ void MemoryManager::release_pte(PageDirectory& page_directory, VirtualAddress va pde.clear(); auto result = page_directory.m_page_tables.remove(vaddr.get() & ~0x1fffff); - VERIFY(result); + VERIFY(unsafe_ignore_missing_page_table == UnsafeIgnoreMissingPageTable::Yes || result); } } } diff --git a/Kernel/Memory/MemoryManager.h b/Kernel/Memory/MemoryManager.h index 3b0b537aec..d4c32beb2f 100644 --- a/Kernel/Memory/MemoryManager.h +++ b/Kernel/Memory/MemoryManager.h @@ -49,19 +49,19 @@ inline FlatPtr virtual_to_low_physical(FlatPtr virtual_) enum class UsedMemoryRangeType { LowMemory = 0, - Prekernel, Kernel, BootModule, PhysicalPages, + __Count }; static constexpr StringView UserMemoryRangeTypeNames[] { "Low memory", - "Prekernel", "Kernel", "Boot module", "Physical Pages" }; +static_assert(array_size(UserMemoryRangeTypeNames) == to_underlying(UsedMemoryRangeType::__Count)); struct UsedMemoryRange { UsedMemoryRangeType type {}; @@ -159,6 +159,7 @@ public: void set_page_writable_direct(VirtualAddress, bool); void protect_readonly_after_init_memory(); + void unmap_prekernel(); void unmap_text_after_init(); void protect_ksyms_after_init(); @@ -276,7 +277,15 @@ private: PageTableEntry* pte(PageDirectory&, VirtualAddress); PageTableEntry* ensure_pte(PageDirectory&, VirtualAddress); - void release_pte(PageDirectory&, VirtualAddress, bool); + enum class IsLastPTERelease { + Yes, + No + }; + enum class UnsafeIgnoreMissingPageTable { + Yes, + No + }; + void release_pte(PageDirectory&, VirtualAddress, IsLastPTERelease, UnsafeIgnoreMissingPageTable = UnsafeIgnoreMissingPageTable::No); RefPtr<PageDirectory> m_kernel_page_directory; diff --git a/Kernel/Memory/Region.cpp b/Kernel/Memory/Region.cpp index 8bb78447af..535a32d458 100644 --- a/Kernel/Memory/Region.cpp +++ b/Kernel/Memory/Region.cpp @@ -243,7 +243,7 @@ void Region::unmap(ShouldDeallocateVirtualRange deallocate_range) size_t count = page_count(); for (size_t i = 0; i < count; ++i) { auto vaddr = vaddr_from_page_index(i); - MM.release_pte(*m_page_directory, vaddr, i == count - 1); + MM.release_pte(*m_page_directory, vaddr, i == count - 1 ? MemoryManager::IsLastPTERelease::Yes : MemoryManager::IsLastPTERelease::No); } MemoryManager::flush_tlb(m_page_directory, vaddr(), page_count()); if (deallocate_range == ShouldDeallocateVirtualRange::Yes) { diff --git a/Kernel/init.cpp b/Kernel/init.cpp index fee2ec1af9..676d970a70 100644 --- a/Kernel/init.cpp +++ b/Kernel/init.cpp @@ -193,6 +193,8 @@ extern "C" [[noreturn]] UNMAP_AFTER_INIT void init(BootInfo const& boot_info) CommandLine::initialize(); Memory::MemoryManager::initialize(0); + MM.unmap_prekernel(); + // Ensure that the safemem sections are not empty. This could happen if the linker accidentally discards the sections. VERIFY(+start_of_safemem_text != +end_of_safemem_text); VERIFY(+start_of_safemem_atomic_text != +end_of_safemem_atomic_text); |