Kernel: Slap UNMAP_AFTER_INIT on a whole bunch of functions

There's no real system here, I just added it to various functions
that I don't believe we ever want to call after initialization
has finished.

With these changes, we're able to unmap 60 KiB of kernel text
after init. :^)

Kernel/Arch/i386/CPU.cpp

@@ -454,24 +454,24 @@ void unregister_generic_interrupt_handler(u8 interrupt_number, GenericInterruptH
     ASSERT_NOT_REACHED();
 }
 
-void register_interrupt_handler(u8 index, void (*f)())
+UNMAP_AFTER_INIT void register_interrupt_handler(u8 index, void (*f)())
 {
     s_idt[index].low = 0x00080000 | LSW((f));
     s_idt[index].high = ((u32)(f)&0xffff0000) | 0x8e00;
 }
 
-void register_user_callable_interrupt_handler(u8 index, void (*f)())
+UNMAP_AFTER_INIT void register_user_callable_interrupt_handler(u8 index, void (*f)())
 {
     s_idt[index].low = 0x00080000 | LSW((f));
     s_idt[index].high = ((u32)(f)&0xffff0000) | 0xef00;
 }
 
-void flush_idt()
+UNMAP_AFTER_INIT void flush_idt()
 {
     asm("lidt %0" ::"m"(s_idtr));
 }
 
-static void idt_init()
+UNMAP_AFTER_INIT static void idt_init()
 {
     s_idtr.address = s_idt;
     s_idtr.limit = 256 * 8 - 1;
@@ -815,7 +815,7 @@ Processor& Processor::by_id(u32 cpu)
     }
 }
 
-void Processor::cpu_detect()
+UNMAP_AFTER_INIT void Processor::cpu_detect()
 {
     // NOTE: This is called during Processor::early_initialize, we cannot
     //       safely log at this point because we don't have kmalloc
@@ -900,7 +900,7 @@ void Processor::cpu_detect()
         set_feature(CPUFeature::RDSEED);
 }
 
-void Processor::cpu_setup()
+UNMAP_AFTER_INIT void Processor::cpu_setup()
 {
     // NOTE: This is called during Processor::early_initialize, we cannot
     //       safely log at this point because we don't have kmalloc
@@ -1013,7 +1013,7 @@ String Processor::features_string() const
     return builder.build();
 }
 
-void Processor::early_initialize(u32 cpu)
+UNMAP_AFTER_INIT void Processor::early_initialize(u32 cpu)
 {
     m_self = this;
 
@@ -1048,7 +1048,7 @@ void Processor::early_initialize(u32 cpu)
     ASSERT(&current() == this); // sanity check
 }
 
-void Processor::initialize(u32 cpu)
+UNMAP_AFTER_INIT void Processor::initialize(u32 cpu)
 {
     ASSERT(m_self == this);
     ASSERT(&current() == this); // sanity check
@@ -1774,7 +1774,7 @@ u32 Processor::smp_wake_n_idle_processors(u32 wake_count)
     return did_wake_count;
 }
 
-void Processor::smp_enable()
+UNMAP_AFTER_INIT void Processor::smp_enable()
 {
     size_t msg_pool_size = Processor::count() * 100u;
     size_t msg_entries_cnt = Processor::count();
@@ -2167,7 +2167,7 @@ void Processor::deferred_call_queue(void (*callback)(void*), void* data, void (*
     cur_proc.deferred_call_queue_entry(entry);
 }
 
-void Processor::gdt_init()
+UNMAP_AFTER_INIT void Processor::gdt_init()
 {
     m_gdt_length = 0;
     m_gdtr.address = nullptr;

Kernel/Console.cpp

@@ -36,7 +36,7 @@
 static AK::Singleton<Console> s_the;
 static Kernel::SpinLock g_console_lock;
 
-void Console::initialize()
+UNMAP_AFTER_INIT void Console::initialize()
 {
     s_the.ensure_instance();
 }
@@ -51,7 +51,7 @@ bool Console::is_initialized()
     return s_the.is_initialized();
 }
 
-Console::Console()
+UNMAP_AFTER_INIT Console::Console()
     : CharacterDevice(5, 1)
 {
 }

Kernel/Devices/FullDevice.cpp

@@ -32,12 +32,12 @@
 
 namespace Kernel {
 
-FullDevice::FullDevice()
+UNMAP_AFTER_INIT FullDevice::FullDevice()
     : CharacterDevice(1, 7)
 {
 }
 
-FullDevice::~FullDevice()
+UNMAP_AFTER_INIT FullDevice::~FullDevice()
 {
 }
 

Kernel/Devices/I8042Controller.cpp

@@ -33,7 +33,7 @@ namespace Kernel {
 
 static I8042Controller* s_the;
 
-void I8042Controller::initialize()
+UNMAP_AFTER_INIT void I8042Controller::initialize()
 {
     if (ACPI::Parser::the()->have_8042())
         new I8042Controller;
@@ -45,7 +45,7 @@ I8042Controller& I8042Controller::the()
     return *s_the;
 }
 
-I8042Controller::I8042Controller()
+UNMAP_AFTER_INIT I8042Controller::I8042Controller()
 {
     ASSERT(!s_the);
     s_the = this;

Kernel/Devices/NullDevice.cpp

@@ -42,12 +42,12 @@ NullDevice& NullDevice::the()
     return *s_the;
 }
 
-NullDevice::NullDevice()
+UNMAP_AFTER_INIT NullDevice::NullDevice()
     : CharacterDevice(1, 3)
 {
 }
 
-NullDevice::~NullDevice()
+UNMAP_AFTER_INIT NullDevice::~NullDevice()
 {
 }
 

Kernel/Devices/RandomDevice.cpp

@@ -29,12 +29,12 @@
 
 namespace Kernel {
 
-RandomDevice::RandomDevice()
+UNMAP_AFTER_INIT RandomDevice::RandomDevice()
     : CharacterDevice(1, 8)
 {
 }
 
-RandomDevice::~RandomDevice()
+UNMAP_AFTER_INIT RandomDevice::~RandomDevice()
 {
 }
 

Kernel/Devices/ZeroDevice.cpp

@@ -30,12 +30,12 @@
 
 namespace Kernel {
 
-ZeroDevice::ZeroDevice()
+UNMAP_AFTER_INIT ZeroDevice::ZeroDevice()
     : CharacterDevice(1, 5)
 {
 }
 
-ZeroDevice::~ZeroDevice()
+UNMAP_AFTER_INIT ZeroDevice::~ZeroDevice()
 {
 }
 

Kernel/FileSystem/VirtualFileSystem.cpp

@@ -44,7 +44,7 @@ static AK::Singleton<VFS> s_the;
 static constexpr int symlink_recursion_limit { 5 }; // FIXME: increase?
 static constexpr int root_mount_flags = MS_NODEV | MS_NOSUID | MS_RDONLY;
 
-void VFS::initialize()
+UNMAP_AFTER_INIT void VFS::initialize()
 {
     s_the.ensure_instance();
 }
@@ -54,14 +54,14 @@ VFS& VFS::the()
     return *s_the;
 }
 
-VFS::VFS()
+UNMAP_AFTER_INIT VFS::VFS()
 {
 #if VFS_DEBUG
     klog() << "VFS: Constructing VFS";
 #endif
 }
 
-VFS::~VFS()
+UNMAP_AFTER_INIT VFS::~VFS()
 {
 }
 

Kernel/Heap/SlabAllocator.cpp

@@ -141,7 +141,7 @@ void for_each_allocator(Callback callback)
     callback(s_slab_allocator_128);
 }
 
-void slab_alloc_init()
+UNMAP_AFTER_INIT void slab_alloc_init()
 {
     s_slab_allocator_16.init(128 * KiB);
     s_slab_allocator_32.init(128 * KiB);

Kernel/Heap/kmalloc.cpp

@@ -211,7 +211,7 @@ void kmalloc_enable_expand()
     g_kmalloc_global->allocate_backup_memory();
 }
 
-void kmalloc_init()
+UNMAP_AFTER_INIT void kmalloc_init()
 {
     // Zero out heap since it's placed after end_of_kernel_bss.
     memset(kmalloc_eternal_heap, 0, sizeof(kmalloc_eternal_heap));

Kernel/Interrupts/APIC.cpp

@@ -146,7 +146,7 @@ APIC& APIC::the()
     return *s_apic;
 }
 
-void APIC::initialize()
+UNMAP_AFTER_INIT void APIC::initialize()
 {
     ASSERT(!APIC::initialized());
     s_apic.ensure_instance();
@@ -234,7 +234,7 @@ u8 APIC::spurious_interrupt_vector()
         + reinterpret_cast<ptrdiff_t>(&varname)                        \
         - reinterpret_cast<ptrdiff_t>(&apic_ap_start))
 
-bool APIC::init_bsp()
+UNMAP_AFTER_INIT bool APIC::init_bsp()
 {
     // FIXME: Use the ACPI MADT table
     if (!MSR::have())
@@ -300,7 +300,7 @@ bool APIC::init_bsp()
     return true;
 }
 
-void APIC::do_boot_aps()
+UNMAP_AFTER_INIT void APIC::do_boot_aps()
 {
     ASSERT(m_processor_enabled_cnt > 1);
     u32 aps_to_enable = m_processor_enabled_cnt - 1;
@@ -400,7 +400,7 @@ void APIC::do_boot_aps()
 #endif
 }
 
-void APIC::boot_aps()
+UNMAP_AFTER_INIT void APIC::boot_aps()
 {
     if (m_processor_enabled_cnt <= 1)
         return;
@@ -421,7 +421,7 @@ void APIC::boot_aps()
     m_apic_ap_continue.store(1, AK::MemoryOrder::memory_order_release);
 }
 
-void APIC::enable(u32 cpu)
+UNMAP_AFTER_INIT void APIC::enable(u32 cpu)
 {
     if (cpu >= 8) {
         // TODO: x2apic support?
@@ -472,7 +472,7 @@ Thread* APIC::get_idle_thread(u32 cpu) const
     return m_ap_idle_threads[cpu - 1];
 }
 
-void APIC::init_finished(u32 cpu)
+UNMAP_AFTER_INIT void APIC::init_finished(u32 cpu)
 {
     // This method is called once the boot stack is no longer needed
     ASSERT(cpu > 0);
@@ -525,7 +525,7 @@ void APIC::send_ipi(u32 cpu)
     write_icr(ICRReg(IRQ_APIC_IPI + IRQ_VECTOR_BASE, ICRReg::Fixed, ICRReg::Logical, ICRReg::Assert, ICRReg::TriggerMode::Edge, ICRReg::NoShorthand, cpu));
 }
 
-APICTimer* APIC::initialize_timers(HardwareTimerBase& calibration_timer)
+UNMAP_AFTER_INIT APICTimer* APIC::initialize_timers(HardwareTimerBase& calibration_timer)
 {
     if (!m_apic_base)
         return nullptr;

Kernel/Interrupts/InterruptManagement.cpp

@@ -56,7 +56,7 @@ InterruptManagement& InterruptManagement::the()
     return *s_interrupt_management;
 }
 
-void InterruptManagement::initialize()
+UNMAP_AFTER_INIT void InterruptManagement::initialize()
 {
     ASSERT(!InterruptManagement::initialized());
     s_interrupt_management = new InterruptManagement();
@@ -125,7 +125,7 @@ RefPtr<IRQController> InterruptManagement::get_responsible_irq_controller(u8 int
     ASSERT_NOT_REACHED();
 }
 
-PhysicalAddress InterruptManagement::search_for_madt()
+UNMAP_AFTER_INIT PhysicalAddress InterruptManagement::search_for_madt()
 {
     dbgln("Early access to ACPI tables for interrupt setup");
     auto rsdp = ACPI::StaticParsing::find_rsdp();
@@ -134,13 +134,13 @@ PhysicalAddress InterruptManagement::search_for_madt()
     return ACPI::StaticParsing::find_table(rsdp.value(), "APIC");
 }
 
-InterruptManagement::InterruptManagement()
+UNMAP_AFTER_INIT InterruptManagement::InterruptManagement()
     : m_madt(search_for_madt())
 {
     m_interrupt_controllers.resize(1);
 }
 
-void InterruptManagement::switch_to_pic_mode()
+UNMAP_AFTER_INIT void InterruptManagement::switch_to_pic_mode()
 {
     klog() << "Interrupts: Switch to Legacy PIC mode";
     InterruptDisabler disabler;
@@ -159,7 +159,7 @@ void InterruptManagement::switch_to_pic_mode()
     }
 }
 
-void InterruptManagement::switch_to_ioapic_mode()
+UNMAP_AFTER_INIT void InterruptManagement::switch_to_ioapic_mode()
 {
     klog() << "Interrupts: Switch to IOAPIC mode";
     InterruptDisabler disabler;
@@ -196,7 +196,7 @@ void InterruptManagement::switch_to_ioapic_mode()
     APIC::the().init_bsp();
 }
 
-void InterruptManagement::locate_apic_data()
+UNMAP_AFTER_INIT void InterruptManagement::locate_apic_data()
 {
     ASSERT(!m_madt.is_null());
     auto madt = map_typed<ACPI::Structures::MADT>(m_madt);

Kernel/Process.cpp

@@ -78,7 +78,7 @@ ProcessID Process::allocate_pid()
     return next_pid.fetch_add(1, AK::MemoryOrder::memory_order_acq_rel);
 }
 
-void Process::initialize()
+UNMAP_AFTER_INIT void Process::initialize()
 {
     g_modules = new HashMap<String, OwnPtr<Module>>;
 

Kernel/Scheduler.cpp

@@ -168,7 +168,7 @@ void Scheduler::queue_runnable_thread(Thread& thread)
         g_ready_queues_mask |= (1u << priority);
 }
 
-void Scheduler::start()
+UNMAP_AFTER_INIT void Scheduler::start()
 {
     ASSERT_INTERRUPTS_DISABLED();
 
@@ -488,7 +488,7 @@ Process* Scheduler::colonel()
     return s_colonel_process;
 }
 
-void Scheduler::initialize()
+UNMAP_AFTER_INIT void Scheduler::initialize()
 {
     ASSERT(&Processor::current() != nullptr); // sanity check
 

Kernel/TTY/PTYMultiplexer.cpp

@@ -42,7 +42,7 @@ PTYMultiplexer& PTYMultiplexer::the()
     return *s_the;
 }
 
-PTYMultiplexer::PTYMultiplexer()
+UNMAP_AFTER_INIT PTYMultiplexer::PTYMultiplexer()
     : CharacterDevice(5, 2)
 {
     m_freelist.ensure_capacity(s_max_pty_pairs);
@@ -50,7 +50,7 @@ PTYMultiplexer::PTYMultiplexer()
         m_freelist.unchecked_append(i - 1);
 }
 
-PTYMultiplexer::~PTYMultiplexer()
+UNMAP_AFTER_INIT PTYMultiplexer::~PTYMultiplexer()
 {
 }
 

Kernel/TTY/VirtualConsole.cpp

@@ -49,7 +49,7 @@ void VirtualConsole::flush_vga_cursor()
     IO::out8(0x3d5, LSB(value));
 }
 
-void VirtualConsole::initialize()
+UNMAP_AFTER_INIT void VirtualConsole::initialize()
 {
     s_vga_buffer = (u8*)0xc00b8000;
     s_active_console = -1;
@@ -63,7 +63,7 @@ void VirtualConsole::set_graphical(bool graphical)
     m_graphical = graphical;
 }
 
-VirtualConsole::VirtualConsole(const unsigned index)
+UNMAP_AFTER_INIT VirtualConsole::VirtualConsole(const unsigned index)
     : TTY(4, index)
     , m_index(index)
     , m_terminal(*this)
@@ -76,7 +76,7 @@ VirtualConsole::VirtualConsole(const unsigned index)
     s_consoles[index] = this;
 }
 
-VirtualConsole::~VirtualConsole()
+UNMAP_AFTER_INIT VirtualConsole::~VirtualConsole()
 {
     ASSERT_NOT_REACHED();
 }

Kernel/Thread.cpp

@@ -48,7 +48,7 @@ namespace Kernel {
 SpinLock<u8> Thread::g_tid_map_lock;
 READONLY_AFTER_INIT HashMap<ThreadID, Thread*>* Thread::g_tid_map;
 
-void Thread::initialize()
+UNMAP_AFTER_INIT void Thread::initialize()
 {
     g_tid_map = new HashMap<ThreadID, Thread*>();
 }

Kernel/Time/APICTimer.cpp

@@ -36,7 +36,7 @@ namespace Kernel {
 
 #define APIC_TIMER_MEASURE_CPU_CLOCK
 
-APICTimer* APICTimer::initialize(u8 interrupt_number, HardwareTimerBase& calibration_source)
+UNMAP_AFTER_INIT APICTimer* APICTimer::initialize(u8 interrupt_number, HardwareTimerBase& calibration_source)
 {
     auto* timer = new APICTimer(interrupt_number, nullptr);
     if (!timer->calibrate(calibration_source)) {
@@ -46,13 +46,13 @@ APICTimer* APICTimer::initialize(u8 interrupt_number, HardwareTimerBase& calibra
     return timer;
 }
 
-APICTimer::APICTimer(u8 interrupt_number, Function<void(const RegisterState&)> callback)
+UNMAP_AFTER_INIT APICTimer::APICTimer(u8 interrupt_number, Function<void(const RegisterState&)> callback)
     : HardwareTimer<GenericInterruptHandler>(interrupt_number, move(callback))
 {
     disable_remap();
 }
 
-bool APICTimer::calibrate(HardwareTimerBase& calibration_source)
+UNMAP_AFTER_INIT bool APICTimer::calibrate(HardwareTimerBase& calibration_source)
 {
     ASSERT_INTERRUPTS_DISABLED();
 

Kernel/Time/TimeManagement.cpp

@@ -145,7 +145,7 @@ u64 TimeManagement::uptime_ms() const
     return ms;
 }
 
-void TimeManagement::initialize(u32 cpu)
+UNMAP_AFTER_INIT void TimeManagement::initialize(u32 cpu)
 {
     if (cpu == 0) {
         ASSERT(!s_the.is_initialized());
@@ -187,7 +187,7 @@ time_t TimeManagement::boot_time() const
     return RTC::boot_time();
 }
 
-TimeManagement::TimeManagement()
+UNMAP_AFTER_INIT TimeManagement::TimeManagement()
 {
     bool probe_non_legacy_hardware_timers = !(kernel_command_line().lookup("time").value_or("modern") == "legacy");
     if (ACPI::is_enabled()) {
@@ -255,7 +255,7 @@ bool TimeManagement::is_hpet_periodic_mode_allowed()
     ASSERT_NOT_REACHED();
 }
 
-bool TimeManagement::probe_and_set_non_legacy_hardware_timers()
+UNMAP_AFTER_INIT bool TimeManagement::probe_and_set_non_legacy_hardware_timers()
 {
     if (!ACPI::is_enabled())
         return false;
@@ -309,7 +309,7 @@ bool TimeManagement::probe_and_set_non_legacy_hardware_timers()
     return true;
 }
 
-bool TimeManagement::probe_and_set_legacy_hardware_timers()
+UNMAP_AFTER_INIT bool TimeManagement::probe_and_set_legacy_hardware_timers()
 {
     if (ACPI::is_enabled()) {
         if (ACPI::Parser::the()->x86_specific_flags().cmos_rtc_not_present) {

Kernel/VM/MemoryManager.cpp

@@ -81,7 +81,7 @@ bool MemoryManager::is_initialized()
     return s_the != nullptr;
 }
 
-MemoryManager::MemoryManager()
+UNMAP_AFTER_INIT MemoryManager::MemoryManager()
 {
     ScopedSpinLock lock(s_mm_lock);
     m_kernel_page_directory = PageDirectory::create_kernel_page_directory();
@@ -104,11 +104,11 @@ MemoryManager::MemoryManager()
     m_lazy_committed_page = allocate_committed_user_physical_page();
 }
 
-MemoryManager::~MemoryManager()
+UNMAP_AFTER_INIT MemoryManager::~MemoryManager()
 {
 }
 
-void MemoryManager::protect_kernel_image()
+UNMAP_AFTER_INIT void MemoryManager::protect_kernel_image()
 {
     ScopedSpinLock page_lock(kernel_page_directory().get_lock());
     // Disable writing to the kernel text and rodata segments.
@@ -125,7 +125,7 @@ void MemoryManager::protect_kernel_image()
     }
 }
 
-void MemoryManager::protect_readonly_after_init_memory()
+UNMAP_AFTER_INIT void MemoryManager::protect_readonly_after_init_memory()
 {
     ScopedSpinLock mm_lock(s_mm_lock);
     ScopedSpinLock page_lock(kernel_page_directory().get_lock());
@@ -153,9 +153,10 @@ void MemoryManager::unmap_memory_after_init()
     }
 
     dmesgln("Unmapped {} KiB of kernel text after init! :^)", (end - start) / KiB);
+    //Processor::halt();
 }
 
-void MemoryManager::register_reserved_ranges()
+UNMAP_AFTER_INIT void MemoryManager::register_reserved_ranges()
 {
     ASSERT(!m_physical_memory_ranges.is_empty());
     ContiguousReservedMemoryRange range;
@@ -194,7 +195,7 @@ bool MemoryManager::is_allowed_to_mmap_to_userspace(PhysicalAddress start_addres
     return false;
 }
 
-void MemoryManager::parse_memory_map()
+UNMAP_AFTER_INIT void MemoryManager::parse_memory_map()
 {
     RefPtr<PhysicalRegion> physical_region;
 
@@ -414,7 +415,7 @@ void MemoryManager::release_pte(PageDirectory& page_directory, VirtualAddress va
     }
 }
 
-void MemoryManager::initialize(u32 cpu)
+UNMAP_AFTER_INIT void MemoryManager::initialize(u32 cpu)
 {
     auto mm_data = new MemoryManagerData;
     Processor::current().set_mm_data(*mm_data);

Kernel/VM/PageDirectory.cpp

@@ -54,7 +54,7 @@ extern "C" PageDirectoryEntry* boot_pdpt[4];
 extern "C" PageDirectoryEntry boot_pd0[1024];
 extern "C" PageDirectoryEntry boot_pd3[1024];
 
-PageDirectory::PageDirectory()
+UNMAP_AFTER_INIT PageDirectory::PageDirectory()
 {
     m_range_allocator.initialize_with_range(VirtualAddress(0xc0800000), 0x3f000000);
     m_identity_range_allocator.initialize_with_range(VirtualAddress(FlatPtr(0x00000000)), 0x00200000);

Kernel/init.cpp

@@ -116,7 +116,7 @@ static Processor s_bsp_processor; // global but let's keep it "private"
 // Once multi-tasking is ready, we spawn a new thread that starts in the
 // init_stage2() function. Initialization continues there.
 
-extern "C" [[noreturn]] void init()
+extern "C" UNMAP_AFTER_INIT [[noreturn]] void init()
 {
     setup_serial_debug();
 
@@ -196,7 +196,7 @@ extern "C" [[noreturn]] void init()
 //
 // The purpose of init_ap() is to initialize APs for multi-tasking.
 //
-extern "C" [[noreturn]] void init_ap(u32 cpu, Processor* processor_info)
+extern "C" UNMAP_AFTER_INIT [[noreturn]] void init_ap(u32 cpu, Processor* processor_info)
 {
     processor_info->early_initialize(cpu);
 
@@ -213,7 +213,7 @@ extern "C" [[noreturn]] void init_ap(u32 cpu, Processor* processor_info)
 // This method is called once a CPU enters the scheduler and its idle thread
 // At this point the initial boot stack can be freed
 //
-extern "C" void init_finished(u32 cpu)
+extern "C" UNMAP_AFTER_INIT void init_finished(u32 cpu)
 {
     if (cpu == 0) {
         // TODO: we can reuse the boot stack, maybe for kmalloc()?
@@ -323,7 +323,7 @@ void init_stage2(void*)
     ASSERT_NOT_REACHED();
 }
 
-void setup_serial_debug()
+UNMAP_AFTER_INIT void setup_serial_debug()
 {
     // serial_debug will output all the klog() and dbgln() data to COM1 at
     // 8-N-1 57600 baud. this is particularly useful for debugging the boot