// Copyright 2015 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <algorithm>
#include <bitset>
#include <ctime>
#include <memory>
#include <random>
#include "common/alignment.h"
#include "common/assert.h"
#include "common/logging/log.h"
#include "common/settings.h"
#include "core/core.h"
#include "core/device_memory.h"
#include "core/file_sys/program_metadata.h"
#include "core/hle/kernel/code_set.h"
#include "core/hle/kernel/k_memory_block_manager.h"
#include "core/hle/kernel/k_page_table.h"
#include "core/hle/kernel/k_resource_limit.h"
#include "core/hle/kernel/k_scheduler.h"
#include "core/hle/kernel/k_scoped_resource_reservation.h"
#include "core/hle/kernel/k_slab_heap.h"
#include "core/hle/kernel/k_thread.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/process.h"
#include "core/hle/kernel/svc_results.h"
#include "core/hle/lock.h"
#include "core/memory.h"
namespace Kernel {
namespace {
/**
* Sets up the primary application thread
*
* @param system The system instance to create the main thread under.
* @param owner_process The parent process for the main thread
* @param priority The priority to give the main thread
*/
void SetupMainThread(Core::System& system, Process& owner_process, u32 priority, VAddr stack_top) {
const VAddr entry_point = owner_process.PageTable().GetCodeRegionStart();
ASSERT(owner_process.GetResourceLimit()->Reserve(LimitableResource::Threads, 1));
KThread* thread = KThread::Create(system.Kernel());
ASSERT(KThread::InitializeUserThread(system, thread, entry_point, 0, stack_top, priority,
owner_process.GetIdealCoreId(), &owner_process)
.IsSuccess());
// Register 1 must be a handle to the main thread
Handle thread_handle{};
owner_process.GetHandleTable().Add(&thread_handle, thread);
thread->SetName("main");
thread->GetContext32().cpu_registers[0] = 0;
thread->GetContext64().cpu_registers[0] = 0;
thread->GetContext32().cpu_registers[1] = thread_handle;
thread->GetContext64().cpu_registers[1] = thread_handle;
auto& kernel = system.Kernel();
// Threads by default are dormant, wake up the main thread so it runs when the scheduler fires
{
KScopedSchedulerLock lock{kernel};
thread->SetState(ThreadState::Runnable);
}
}
} // Anonymous namespace
// Represents a page used for thread-local storage.
//
// Each TLS page contains slots that may be used by processes and threads.
// Every process and thread is created with a slot in some arbitrary page
// (whichever page happens to have an available slot).
class TLSPage {
public:
static constexpr std::size_t num_slot_entries =
Core::Memory::PAGE_SIZE / Core::Memory::TLS_ENTRY_SIZE;
explicit TLSPage(VAddr address) : base_address{address} {}
bool HasAvailableSlots() const {
return !is_slot_used.all();
}
VAddr GetBaseAddress() const {
return base_address;
}
std::optional<VAddr> ReserveSlot() {
for (std::size_t i = 0; i < is_slot_used.size(); i++) {
if (is_slot_used[i]) {
continue;
}
is_slot_used[i] = true;
return base_address + (i * Core::Memory::TLS_ENTRY_SIZE);
}
return std::nullopt;
}
void ReleaseSlot(VAddr address) {
// Ensure that all given addresses are consistent with how TLS pages
// are intended to be used when releasing slots.
ASSERT(IsWithinPage(address));
ASSERT((address % Core::Memory::TLS_ENTRY_SIZE) == 0);
const std::size_t index = (address - base_address) / Core::Memory::TLS_ENTRY_SIZE;
is_slot_used[index] = false;
}
private:
bool IsWithinPage(VAddr address) const {
return base_address <= address && address < base_address + Core::Memory::PAGE_SIZE;
}
VAddr base_address;
std::bitset<num_slot_entries> is_slot_used;
};
ResultCode Process::Initialize(Process* process, Core::System& system, std::string name,
ProcessType type) {
auto& kernel = system.Kernel();
process->name = std::move(name);
process->resource_limit = kernel.GetSystemResourceLimit();
process->status = ProcessStatus::Created;
process->program_id = 0;
process->process_id = type == ProcessType::KernelInternal ? kernel.CreateNewKernelProcessID()
: kernel.CreateNewUserProcessID();
process->capabilities.InitializeForMetadatalessProcess();
process->is_initialized = true;
std::mt19937 rng(Settings::values.rng_seed.GetValue().value_or(std::time(nullptr)));
std::uniform_int_distribution<u64> distribution;
std::generate(process->random_entropy.begin(), process->random_entropy.end(),
[&] { return distribution(rng); });
kernel.AppendNewProcess(process);
return RESULT_SUCCESS;
}
std::shared_ptr<KResourceLimit> Process::GetResourceLimit() const {
return resource_limit;
}
void Process::IncrementThreadCount() {
ASSERT(num_threads >= 0);
num_created_threads++;
if (const auto count = ++num_threads; count > peak_num_threads) {
peak_num_threads = count;
}
}
void Process::DecrementThreadCount() {
ASSERT(num_threads > 0);
if (const auto count = --num_threads; count == 0) {
UNIMPLEMENTED_MSG("Process termination is not implemented!");
}
}
u64 Process::GetTotalPhysicalMemoryAvailable() const {
const u64 capacity{resource_limit->GetFreeValue(LimitableResource::PhysicalMemory) +
page_table->GetTotalHeapSize() + GetSystemResourceSize() + image_size +
main_thread_stack_size};
ASSERT(capacity == kernel.MemoryManager().GetSize(KMemoryManager::Pool::Application));
if (capacity < memory_usage_capacity) {
return capacity;
}
return memory_usage_capacity;
}
u64 Process::GetTotalPhysicalMemoryAvailableWithoutSystemResource() const {
return GetTotalPhysicalMemoryAvailable() - GetSystemResourceSize();
}
u64 Process::GetTotalPhysicalMemoryUsed() const {
return image_size + main_thread_stack_size + page_table->GetTotalHeapSize() +
GetSystemResourceSize();
}
u64 Process::GetTotalPhysicalMemoryUsedWithoutSystemResource() const {
return GetTotalPhysicalMemoryUsed() - GetSystemResourceUsage();
}
bool Process::ReleaseUserException(KThread* thread) {
KScopedSchedulerLock sl{kernel};
if (exception_thread == thread) {
exception_thread = nullptr;
// Remove waiter thread.
s32 num_waiters{};
KThread* next = thread->RemoveWaiterByKey(
std::addressof(num_waiters),
reinterpret_cast<uintptr_t>(std::addressof(exception_thread)));
if (next != nullptr) {
if (next->GetState() == ThreadState::Waiting) {
next->SetState(ThreadState::Runnable);
} else {
KScheduler::SetSchedulerUpdateNeeded(kernel);
}
}
return true;
} else {
return false;
}
}
void Process::PinCurrentThread() {
ASSERT(kernel.GlobalSchedulerContext().IsLocked());
// Get the current thread.
const s32 core_id = GetCurrentCoreId(kernel);
KThread* cur_thread = GetCurrentThreadPointer(kernel);
// Pin it.
PinThread(core_id, cur_thread);
cur_thread->Pin();
// An update is needed.
KScheduler::SetSchedulerUpdateNeeded(kernel);
}
void Process::UnpinCurrentThread() {
ASSERT(kernel.GlobalSchedulerContext().IsLocked());
// Get the current thread.
const s32 core_id = GetCurrentCoreId(kernel);
KThread* cur_thread = GetCurrentThreadPointer(kernel);
// Unpin it.
cur_thread->Unpin();
UnpinThread(core_id, cur_thread);
// An update is needed.
KScheduler::SetSchedulerUpdateNeeded(kernel);
}
void Process::RegisterThread(const KThread* thread) {
thread_list.push_back(thread);
}
void Process::UnregisterThread(const KThread* thread) {
thread_list.remove(thread);
}
ResultCode Process::Reset() {
// Lock the process and the scheduler.
KScopedLightLock lk(state_lock);
KScopedSchedulerLock sl{kernel};
// Validate that we're in a state that we can reset.
R_UNLESS(status != ProcessStatus::Exited, ResultInvalidState);
R_UNLESS(is_signaled, ResultInvalidState);
// Clear signaled.
is_signaled = false;
return RESULT_SUCCESS;
}
ResultCode Process::LoadFromMetadata(const FileSys::ProgramMetadata& metadata,
std::size_t code_size) {
program_id = metadata.GetTitleID();
ideal_core = metadata.GetMainThreadCore();
is_64bit_process = metadata.Is64BitProgram();
system_resource_size = metadata.GetSystemResourceSize();
image_size = code_size;
KScopedResourceReservation memory_reservation(resource_limit, LimitableResource::PhysicalMemory,
code_size + system_resource_size);
if (!memory_reservation.Succeeded()) {
LOG_ERROR(Kernel, "Could not reserve process memory requirements of size {:X} bytes",
code_size + system_resource_size);
return ResultResourceLimitedExceeded;
}
// Initialize proces address space
if (const ResultCode result{
page_table->InitializeForProcess(metadata.GetAddressSpaceType(), false, 0x8000000,
code_size, KMemoryManager::Pool::Application)};
result.IsError()) {
return result;
}
// Map process code region
if (const ResultCode result{page_table->MapProcessCode(page_table->GetCodeRegionStart(),
code_size / PageSize, KMemoryState::Code,
KMemoryPermission::None)};
result.IsError()) {
return result;
}
// Initialize process capabilities
const auto& caps{metadata.GetKernelCapabilities()};
if (const ResultCode result{
capabilities.InitializeForUserProcess(caps.data(), caps.size(), *page_table)};
result.IsError()) {
return result;
}
// Set memory usage capacity
switch (metadata.GetAddressSpaceType()) {
case FileSys::ProgramAddressSpaceType::Is32Bit:
case FileSys::ProgramAddressSpaceType::Is36Bit:
case FileSys::ProgramAddressSpaceType::Is39Bit:
memory_usage_capacity = page_table->GetHeapRegionEnd() - page_table->GetHeapRegionStart();
break;
case FileSys::ProgramAddressSpaceType::Is32BitNoMap:
memory_usage_capacity = page_table->GetHeapRegionEnd() - page_table->GetHeapRegionStart() +
page_table->GetAliasRegionEnd() - page_table->GetAliasRegionStart();
break;
default:
UNREACHABLE();
}
// Create TLS region
tls_region_address = CreateTLSRegion();
memory_reservation.Commit();
return handle_table.SetSize(capabilities.GetHandleTableSize());
}
void Process::Run(s32 main_thread_priority, u64 stack_size) {
AllocateMainThreadStack(stack_size);
resource_limit->Reserve(LimitableResource::Threads, 1);
resource_limit->Reserve(LimitableResource::PhysicalMemory, main_thread_stack_size);
const std::size_t heap_capacity{memory_usage_capacity - main_thread_stack_size - image_size};
ASSERT(!page_table->SetHeapCapacity(heap_capacity).IsError());
ChangeStatus(ProcessStatus::Running);
SetupMainThread(kernel.System(), *this, main_thread_priority, main_thread_stack_top);
}
void Process::PrepareForTermination() {
ChangeStatus(ProcessStatus::Exiting);
const auto stop_threads = [this](const std::vector<KThread*>& thread_list) {
for (auto& thread : thread_list) {
if (thread->GetOwnerProcess() != this)
continue;
if (thread == kernel.CurrentScheduler()->GetCurrentThread())
continue;
// TODO(Subv): When are the other running/ready threads terminated?
ASSERT_MSG(thread->GetState() == ThreadState::Waiting,
"Exiting processes with non-waiting threads is currently unimplemented");
thread->Exit();
}
};
stop_threads(kernel.System().GlobalSchedulerContext().GetThreadList());
FreeTLSRegion(tls_region_address);
tls_region_address = 0;
if (resource_limit) {
resource_limit->Release(LimitableResource::PhysicalMemory,
main_thread_stack_size + image_size);
}
ChangeStatus(ProcessStatus::Exited);
}
/**
* Attempts to find a TLS page that contains a free slot for
* use by a thread.
*
* @returns If a page with an available slot is found, then an iterator
* pointing to the page is returned. Otherwise the end iterator
* is returned instead.
*/
static auto FindTLSPageWithAvailableSlots(std::vector<TLSPage>& tls_pages) {
return std::find_if(tls_pages.begin(), tls_pages.end(),
[](const auto& page) { return page.HasAvailableSlots(); });
}
VAddr Process::CreateTLSRegion() {
KScopedSchedulerLock lock(kernel);
if (auto tls_page_iter{FindTLSPageWithAvailableSlots(tls_pages)};
tls_page_iter != tls_pages.cend()) {
return *tls_page_iter->ReserveSlot();
}
Page* const tls_page_ptr{kernel.GetUserSlabHeapPages().Allocate()};
ASSERT(tls_page_ptr);
const VAddr start{page_table->GetKernelMapRegionStart()};
const VAddr size{page_table->GetKernelMapRegionEnd() - start};
const PAddr tls_map_addr{kernel.System().DeviceMemory().GetPhysicalAddr(tls_page_ptr)};
const VAddr tls_page_addr{page_table
->AllocateAndMapMemory(1, PageSize, true, start, size / PageSize,
KMemoryState::ThreadLocal,
KMemoryPermission::ReadAndWrite,
tls_map_addr)
.ValueOr(0)};
ASSERT(tls_page_addr);
std::memset(tls_page_ptr, 0, PageSize);
tls_pages.emplace_back(tls_page_addr);
const auto reserve_result{tls_pages.back().ReserveSlot()};
ASSERT(reserve_result.has_value());
return *reserve_result;
}
void Process::FreeTLSRegion(VAddr tls_address) {
KScopedSchedulerLock lock(kernel);
const VAddr aligned_address = Common::AlignDown(tls_address, Core::Memory::PAGE_SIZE);
auto iter =
std::find_if(tls_pages.begin(), tls_pages.end(), [aligned_address](const auto& page) {
return page.GetBaseAddress() == aligned_address;
});
// Something has gone very wrong if we're freeing a region
// with no actual page available.
ASSERT(iter != tls_pages.cend());
iter->ReleaseSlot(tls_address);
}
void Process::LoadModule(CodeSet code_set, VAddr base_addr) {
std::lock_guard lock{HLE::g_hle_lock};
const auto ReprotectSegment = [&](const CodeSet::Segment& segment,
KMemoryPermission permission) {
page_table->SetCodeMemoryPermission(segment.addr + base_addr, segment.size, permission);
};
kernel.System().Memory().WriteBlock(*this, base_addr, code_set.memory.data(),
code_set.memory.size());
ReprotectSegment(code_set.CodeSegment(), KMemoryPermission::ReadAndExecute);
ReprotectSegment(code_set.RODataSegment(), KMemoryPermission::Read);
ReprotectSegment(code_set.DataSegment(), KMemoryPermission::ReadAndWrite);
}
bool Process::IsSignaled() const {
ASSERT(kernel.GlobalSchedulerContext().IsLocked());
return is_signaled;
}
Process::Process(KernelCore& kernel)
: KAutoObjectWithSlabHeapAndContainer{kernel},
page_table{std::make_unique<KPageTable>(kernel.System())}, handle_table{kernel},
address_arbiter{kernel.System()}, condition_var{kernel.System()}, state_lock{kernel} {}
Process::~Process() = default;
void Process::ChangeStatus(ProcessStatus new_status) {
if (status == new_status) {
return;
}
status = new_status;
is_signaled = true;
NotifyAvailable();
}
ResultCode Process::AllocateMainThreadStack(std::size_t stack_size) {
ASSERT(stack_size);
// The kernel always ensures that the given stack size is page aligned.
main_thread_stack_size = Common::AlignUp(stack_size, PageSize);
const VAddr start{page_table->GetStackRegionStart()};
const std::size_t size{page_table->GetStackRegionEnd() - start};
CASCADE_RESULT(main_thread_stack_top,
page_table->AllocateAndMapMemory(
main_thread_stack_size / PageSize, PageSize, false, start, size / PageSize,
KMemoryState::Stack, KMemoryPermission::ReadAndWrite));
main_thread_stack_top += main_thread_stack_size;
return RESULT_SUCCESS;
}
} // namespace Kernel