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Atmosphere/libraries/libmesosphere/source/kern_k_thread.cpp
2020-07-10 23:30:15 -07:00

712 lines
26 KiB
C++

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <mesosphere.hpp>
namespace ams::kern {
namespace {
constexpr bool IsKernelAddressKey(KProcessAddress key) {
const uintptr_t key_uptr = GetInteger(key);
return KernelVirtualAddressSpaceBase <= key_uptr && key_uptr <= KernelVirtualAddressSpaceLast;
}
void CleanupKernelStack(uintptr_t stack_top) {
const uintptr_t stack_bottom = stack_top - PageSize;
KPhysicalAddress stack_paddr = Null<KPhysicalAddress>;
MESOSPHERE_ABORT_UNLESS(Kernel::GetKernelPageTable().GetPhysicalAddress(&stack_paddr, stack_bottom));
MESOSPHERE_R_ABORT_UNLESS(Kernel::GetKernelPageTable().UnmapPages(stack_bottom, 1, KMemoryState_Kernel));
/* Free the stack page. */
KPageBuffer::Free(KPageBuffer::FromPhysicalAddress(stack_paddr));
}
}
Result KThread::Initialize(KThreadFunction func, uintptr_t arg, void *kern_stack_top, KProcessAddress user_stack_top, s32 prio, s32 core, KProcess *owner, ThreadType type) {
/* Assert parameters are valid. */
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(kern_stack_top != nullptr);
MESOSPHERE_ASSERT((type == ThreadType_Main) || (ams::svc::HighestThreadPriority <= prio && prio <= ams::svc::LowestThreadPriority));
MESOSPHERE_ASSERT((owner != nullptr) || (type != ThreadType_User));
MESOSPHERE_ASSERT(0 <= core && core < static_cast<s32>(cpu::NumCores));
/* First, clear the TLS address. */
this->tls_address = Null<KProcessAddress>;
const uintptr_t kern_stack_top_address = reinterpret_cast<uintptr_t>(kern_stack_top);
/* Next, assert things based on the type. */
switch (type) {
case ThreadType_Main:
{
MESOSPHERE_ASSERT(arg == 0);
}
[[fallthrough]];
case ThreadType_HighPriority:
{
MESOSPHERE_ASSERT(core == GetCurrentCoreId());
}
[[fallthrough]];
case ThreadType_Kernel:
{
MESOSPHERE_ASSERT(user_stack_top == 0);
MESOSPHERE_ASSERT(util::IsAligned(kern_stack_top_address, PageSize));
}
[[fallthrough]];
case ThreadType_User:
{
MESOSPHERE_ASSERT(((owner == nullptr) || (owner->GetCoreMask() | (1ul << core)) == owner->GetCoreMask()));
MESOSPHERE_ASSERT(((owner == nullptr) || (owner->GetPriorityMask() | (1ul << prio)) == owner->GetPriorityMask()));
}
break;
default:
MESOSPHERE_PANIC("KThread::Initialize: Unknown ThreadType %u", static_cast<u32>(type));
break;
}
/* Set the ideal core ID and affinity mask. */
this->ideal_core_id = core;
this->affinity_mask.SetAffinity(core, true);
/* Set the thread state. */
this->thread_state = (type == ThreadType_Main) ? ThreadState_Runnable : ThreadState_Initialized;
/* Set TLS address and TLS heap address. */
/* NOTE: Nintendo wrote TLS address above already, but official code really does write tls address twice. */
this->tls_address = 0;
this->tls_heap_address = 0;
/* Set parent and condvar tree. */
this->parent = nullptr;
this->cond_var = nullptr;
/* Set sync booleans. */
this->signaled = false;
this->ipc_cancelled = false;
this->termination_requested = false;
this->wait_cancelled = false;
this->cancellable = false;
/* Set core ID and wait result. */
this->core_id = this->ideal_core_id;
this->wait_result = svc::ResultNoSynchronizationObject();
/* Set the stack top. */
this->kernel_stack_top = kern_stack_top;
/* Set priorities. */
this->priority = prio;
this->base_priority = prio;
/* Set sync object and waiting lock to null. */
this->synced_object = nullptr;
this->waiting_lock = nullptr;
/* Initialize sleeping queue. */
this->sleeping_queue_entry.Initialize();
this->sleeping_queue = nullptr;
/* Set suspend flags. */
this->suspend_request_flags = 0;
this->suspend_allowed_flags = ThreadState_SuspendFlagMask;
/* We're neither debug attached, nor are we nesting our priority inheritance. */
this->debug_attached = false;
this->priority_inheritance_count = 0;
/* We haven't been scheduled, and we have done no light IPC. */
this->schedule_count = -1;
this->last_scheduled_tick = 0;
this->light_ipc_data = nullptr;
/* We're not waiting for a lock, and we haven't disabled migration. */
this->lock_owner = nullptr;
this->num_core_migration_disables = 0;
/* We have no waiters, but we do have an entrypoint. */
this->num_kernel_waiters = 0;
this->entrypoint = reinterpret_cast<uintptr_t>(func);
/* We don't need a release (probably), and we've spent no time on the cpu. */
this->resource_limit_release_hint = 0;
this->cpu_time = 0;
/* Clear our stack parameters. */
std::memset(static_cast<void *>(std::addressof(this->GetStackParameters())), 0, sizeof(StackParameters));
/* Setup the TLS, if needed. */
if (type == ThreadType_User) {
R_TRY(owner->CreateThreadLocalRegion(std::addressof(this->tls_address)));
this->tls_heap_address = owner->GetThreadLocalRegionPointer(this->tls_address);
std::memset(this->tls_heap_address, 0, ams::svc::ThreadLocalRegionSize);
}
/* Set parent, if relevant. */
if (owner != nullptr) {
this->parent = owner;
this->parent->Open();
this->parent->IncrementThreadCount();
}
/* Initialize thread context. */
constexpr bool IsDefault64Bit = sizeof(uintptr_t) == sizeof(u64);
const bool is_64_bit = this->parent ? this->parent->Is64Bit() : IsDefault64Bit;
const bool is_user = (type == ThreadType_User);
const bool is_main = (type == ThreadType_Main);
this->thread_context.Initialize(this->entrypoint, reinterpret_cast<uintptr_t>(this->GetStackTop()), GetInteger(user_stack_top), arg, is_user, is_64_bit, is_main);
/* Setup the stack parameters. */
StackParameters &sp = this->GetStackParameters();
if (this->parent != nullptr) {
this->parent->CopySvcPermissionsTo(sp);
}
sp.context = std::addressof(this->thread_context);
sp.disable_count = 1;
this->SetInExceptionHandler();
/* Set thread ID. */
this->thread_id = s_next_thread_id++;
/* We initialized! */
this->initialized = true;
/* Register ourselves with our parent process. */
if (this->parent != nullptr) {
this->parent->RegisterThread(this);
if (this->parent->IsSuspended()) {
this->RequestSuspend(SuspendType_Process);
}
}
return ResultSuccess();
}
Result KThread::InitializeThread(KThread *thread, KThreadFunction func, uintptr_t arg, KProcessAddress user_stack_top, s32 prio, s32 core, KProcess *owner, ThreadType type) {
/* Get stack region for the thread. */
const auto &stack_region = KMemoryLayout::GetKernelStackRegion();
/* Allocate a page to use as the thread. */
KPageBuffer *page = KPageBuffer::Allocate();
R_UNLESS(page != nullptr, svc::ResultOutOfResource());
/* Map the stack page. */
KProcessAddress stack_top = Null<KProcessAddress>;
{
KProcessAddress stack_bottom = Null<KProcessAddress>;
auto page_guard = SCOPE_GUARD { KPageBuffer::Free(page); };
R_TRY(Kernel::GetKernelPageTable().MapPages(std::addressof(stack_bottom), 1, PageSize, page->GetPhysicalAddress(), stack_region.GetAddress(),
stack_region.GetSize() / PageSize, KMemoryState_Kernel, KMemoryPermission_KernelReadWrite));
page_guard.Cancel();
/* Calculate top of the stack. */
stack_top = stack_bottom + PageSize;
}
/* Initialize the thread. */
auto map_guard = SCOPE_GUARD { CleanupKernelStack(GetInteger(stack_top)); };
R_TRY(thread->Initialize(func, arg, GetVoidPointer(stack_top), user_stack_top, prio, core, owner, type));
map_guard.Cancel();
return ResultSuccess();
}
void KThread::PostDestroy(uintptr_t arg) {
KProcess *owner = reinterpret_cast<KProcess *>(arg & ~1ul);
const bool resource_limit_release_hint = (arg & 1);
const s64 hint_value = (resource_limit_release_hint ? 0 : 1);
if (owner != nullptr) {
owner->ReleaseResource(ams::svc::LimitableResource_ThreadCountMax, 1, hint_value);
owner->Close();
} else {
Kernel::GetSystemResourceLimit().Release(ams::svc::LimitableResource_ThreadCountMax, 1, hint_value);
}
}
void KThread::ResumeThreadsSuspendedForInit() {
KThread::ListAccessor list_accessor;
{
KScopedSchedulerLock sl;
for (auto &thread : list_accessor) {
static_cast<KThread &>(thread).Resume(SuspendType_Init);
}
}
}
void KThread::Finalize() {
MESOSPHERE_UNIMPLEMENTED();
}
bool KThread::IsSignaled() const {
return this->signaled;
}
void KThread::Wakeup() {
MESOSPHERE_ASSERT_THIS();
KScopedSchedulerLock sl;
if (this->GetState() == ThreadState_Waiting) {
if (this->sleeping_queue != nullptr) {
this->sleeping_queue->WakeupThread(this);
} else {
this->SetState(ThreadState_Runnable);
}
}
}
void KThread::OnTimer() {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(KScheduler::IsSchedulerLockedByCurrentThread());
this->Wakeup();
}
void KThread::StartTermination() {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(KScheduler::IsSchedulerLockedByCurrentThread());
/* Release user exception, if relevant. */
if (this->parent != nullptr) {
this->parent->ReleaseUserException(this);
if (this->parent->GetPreemptionStatePinnedThread(GetCurrentCoreId()) == this) {
/* TODO: this->parent->UnpinCurrentThread(); */
MESOSPHERE_UNIMPLEMENTED();
}
}
/* Set state to terminated. */
this->SetState(KThread::ThreadState_Terminated);
/* Clear the thread's status as running in parent. */
if (this->parent != nullptr) {
this->parent->ClearRunningThread(this);
}
/* Signal. */
this->signaled = true;
this->NotifyAvailable();
/* TODO: On Thread Termination handler */
/* Clear previous thread in KScheduler. */
KScheduler::ClearPreviousThread(this);
/* Register terminated dpc flag. */
this->RegisterDpc(DpcFlag_Terminated);
}
void KThread::FinishTermination() {
MESOSPHERE_ASSERT_THIS();
/* Ensure that the thread is not executing on any core. */
if (this->parent != nullptr) {
for (size_t i = 0; i < cpu::NumCores; ++i) {
KThread *core_thread;
do {
core_thread = Kernel::GetCurrentContext(i).current_thread.load(std::memory_order_acquire);
} while (core_thread == this);
}
}
/* Close the thread. */
this->Close();
}
void KThread::DoWorkerTask() {
/* Finish the termination that was begun by Exit(). */
this->FinishTermination();
}
void KThread::DisableCoreMigration() {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(this == GetCurrentThreadPointer());
KScopedSchedulerLock sl;
MESOSPHERE_ASSERT(this->num_core_migration_disables >= 0);
if ((this->num_core_migration_disables++) == 0) {
/* Save our ideal state to restore when we can migrate again. */
this->original_ideal_core_id = this->ideal_core_id;
this->original_affinity_mask = this->affinity_mask;
/* Bind outselves to this core. */
const s32 active_core = this->GetActiveCore();
this->ideal_core_id = active_core;
this->affinity_mask.SetAffinityMask(1ul << active_core);
if (this->affinity_mask.GetAffinityMask() != this->original_affinity_mask.GetAffinityMask()) {
KScheduler::OnThreadAffinityMaskChanged(this, this->original_affinity_mask, active_core);
}
}
}
void KThread::EnableCoreMigration() {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(this == GetCurrentThreadPointer());
KScopedSchedulerLock sl;
MESOSPHERE_ASSERT(this->num_core_migration_disables > 0);
if ((--this->num_core_migration_disables) == 0) {
const KAffinityMask old_mask = this->affinity_mask;
/* Restore our ideals. */
this->ideal_core_id = this->original_ideal_core_id;
this->original_affinity_mask = this->affinity_mask;
if (this->affinity_mask.GetAffinityMask() != old_mask.GetAffinityMask()) {
const s32 active_core = this->GetActiveCore();
if (!this->affinity_mask.GetAffinity(active_core)) {
if (this->ideal_core_id >= 0) {
this->SetActiveCore(this->ideal_core_id);
} else {
this->SetActiveCore(BITSIZEOF(unsigned long long) - 1 - __builtin_clzll(this->affinity_mask.GetAffinityMask()));
}
}
KScheduler::OnThreadAffinityMaskChanged(this, old_mask, active_core);
}
}
}
Result KThread::SetPriorityToIdle() {
MESOSPHERE_ASSERT_THIS();
KScopedSchedulerLock sl;
/* Change both our priorities to the idle thread priority. */
const s32 old_priority = this->priority;
this->priority = IdleThreadPriority;
this->base_priority = IdleThreadPriority;
KScheduler::OnThreadPriorityChanged(this, old_priority);
return ResultSuccess();
}
void KThread::RequestSuspend(SuspendType type) {
MESOSPHERE_ASSERT_THIS();
KScopedSchedulerLock lk;
/* Note the request in our flags. */
this->suspend_request_flags |= (1u << (ThreadState_SuspendShift + type));
/* Try to perform the suspend. */
this->TrySuspend();
}
void KThread::Resume(SuspendType type) {
MESOSPHERE_ASSERT_THIS();
KScopedSchedulerLock sl;
/* Clear the request in our flags. */
this->suspend_request_flags &= ~(1u << (ThreadState_SuspendShift + type));
/* Update our state. */
const ThreadState old_state = this->thread_state;
this->thread_state = static_cast<ThreadState>(this->GetSuspendFlags() | (old_state & ThreadState_Mask));
if (this->thread_state != old_state) {
KScheduler::OnThreadStateChanged(this, old_state);
}
}
void KThread::TrySuspend() {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(KScheduler::IsSchedulerLockedByCurrentThread());
MESOSPHERE_ASSERT(this->IsSuspended());
/* Ensure that we have no waiters. */
if (this->GetNumKernelWaiters() > 0) {
return;
}
MESOSPHERE_ABORT_UNLESS(this->GetNumKernelWaiters() == 0);
/* Perform the suspend. */
this->Suspend();
}
void KThread::Suspend() {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(KScheduler::IsSchedulerLockedByCurrentThread());
MESOSPHERE_ASSERT(this->IsSuspended());
/* Set our suspend flags in state. */
const auto old_state = this->thread_state;
this->thread_state = static_cast<ThreadState>(this->GetSuspendFlags() | (old_state & ThreadState_Mask));
/* Note the state change in scheduler. */
KScheduler::OnThreadStateChanged(this, old_state);
}
void KThread::Continue() {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(KScheduler::IsSchedulerLockedByCurrentThread());
/* Clear our suspend flags in state. */
const auto old_state = this->thread_state;
this->thread_state = static_cast<ThreadState>(old_state & ThreadState_Mask);
/* Note the state change in scheduler. */
KScheduler::OnThreadStateChanged(this, old_state);
}
void KThread::AddWaiterImpl(KThread *thread) {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(KScheduler::IsSchedulerLockedByCurrentThread());
/* Find the right spot to insert the waiter. */
auto it = this->waiter_list.begin();
while (it != this->waiter_list.end()) {
if (it->GetPriority() > thread->GetPriority()) {
break;
}
it++;
}
/* Keep track of how many kernel waiters we have. */
if (IsKernelAddressKey(thread->GetAddressKey())) {
MESOSPHERE_ABORT_UNLESS((this->num_kernel_waiters++) >= 0);
}
/* Insert the waiter. */
this->waiter_list.insert(it, *thread);
thread->SetLockOwner(this);
}
void KThread::RemoveWaiterImpl(KThread *thread) {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(KScheduler::IsSchedulerLockedByCurrentThread());
/* Keep track of how many kernel waiters we have. */
if (IsKernelAddressKey(thread->GetAddressKey())) {
MESOSPHERE_ABORT_UNLESS((this->num_kernel_waiters--) > 0);
}
/* Remove the waiter. */
this->waiter_list.erase(this->waiter_list.iterator_to(*thread));
thread->SetLockOwner(nullptr);
}
void KThread::RestorePriority(KThread *thread) {
MESOSPHERE_ASSERT(KScheduler::IsSchedulerLockedByCurrentThread());
while (true) {
/* We want to inherit priority where possible. */
s32 new_priority = thread->GetBasePriority();
if (thread->HasWaiters()) {
new_priority = std::min(new_priority, thread->waiter_list.front().GetPriority());
}
/* If the priority we would inherit is not different from ours, don't do anything. */
if (new_priority == thread->GetPriority()) {
return;
}
/* Ensure we don't violate condition variable red black tree invariants. */
if (auto *cond_var = thread->GetConditionVariable(); cond_var != nullptr) {
cond_var->BeforeUpdatePriority(thread);
}
/* Change the priority. */
const s32 old_priority = thread->GetPriority();
thread->SetPriority(new_priority);
/* Restore the condition variable, if relevant. */
if (auto *cond_var = thread->GetConditionVariable(); cond_var != nullptr) {
cond_var->AfterUpdatePriority(thread);
}
/* Update the scheduler. */
KScheduler::OnThreadPriorityChanged(thread, old_priority);
/* Keep the lock owner up to date. */
KThread *lock_owner = thread->GetLockOwner();
if (lock_owner == nullptr) {
return;
}
/* Update the thread in the lock owner's sorted list, and continue inheriting. */
lock_owner->RemoveWaiterImpl(thread);
lock_owner->AddWaiterImpl(thread);
thread = lock_owner;
}
}
void KThread::AddWaiter(KThread *thread) {
MESOSPHERE_ASSERT_THIS();
this->AddWaiterImpl(thread);
RestorePriority(this);
}
void KThread::RemoveWaiter(KThread *thread) {
MESOSPHERE_ASSERT_THIS();
this->RemoveWaiterImpl(thread);
RestorePriority(this);
}
KThread *KThread::RemoveWaiterByKey(s32 *out_num_waiters, KProcessAddress key) {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(KScheduler::IsSchedulerLockedByCurrentThread());
s32 num_waiters = 0;
KThread *next_lock_owner = nullptr;
auto it = this->waiter_list.begin();
while (it != this->waiter_list.end()) {
if (it->GetAddressKey() == key) {
KThread *thread = std::addressof(*it);
/* Keep track of how many kernel waiters we have. */
if (IsKernelAddressKey(thread->GetAddressKey())) {
MESOSPHERE_ABORT_UNLESS((this->num_kernel_waiters--) > 0);
}
it = this->waiter_list.erase(it);
/* Update the next lock owner. */
if (next_lock_owner == nullptr) {
next_lock_owner = thread;
next_lock_owner->SetLockOwner(nullptr);
} else {
next_lock_owner->AddWaiterImpl(thread);
}
num_waiters++;
} else {
it++;
}
}
/* Do priority updates, if we have a next owner. */
if (next_lock_owner) {
RestorePriority(this);
RestorePriority(next_lock_owner);
}
/* Return output. */
*out_num_waiters = num_waiters;
return next_lock_owner;
}
Result KThread::Run() {
MESOSPHERE_ASSERT_THIS();
/* If the kernel hasn't finished initializing, then we should suspend. */
if (Kernel::GetState() != Kernel::State::Initialized) {
this->RequestSuspend(SuspendType_Init);
}
while (true) {
KScopedSchedulerLock lk;
/* If either this thread or the current thread are requesting termination, note it. */
R_UNLESS(!this->IsTerminationRequested(), svc::ResultTerminationRequested());
R_UNLESS(!GetCurrentThread().IsTerminationRequested(), svc::ResultTerminationRequested());
/* Ensure our thread state is correct. */
R_UNLESS(this->GetState() == ThreadState_Initialized, svc::ResultInvalidState());
/* If the current thread has been asked to suspend, suspend it and retry. */
if (GetCurrentThread().IsSuspended()) {
GetCurrentThread().Suspend();
continue;
}
/* If we're not a kernel thread and we've been asked to suspend, suspend ourselves. */
if (this->IsUserThread() && this->IsSuspended()) {
this->Suspend();
}
/* Set our state and finish. */
this->SetState(KThread::ThreadState_Runnable);
return ResultSuccess();
}
}
void KThread::Exit() {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(this == GetCurrentThreadPointer());
/* TODO: KDebug::OnExitThread(this); */
/* Release the thread resource hint from parent. */
if (this->parent != nullptr) {
this->parent->ReleaseResource(ams::svc::LimitableResource_ThreadCountMax, 0, 1);
}
/* Perform termination. */
{
KScopedSchedulerLock sl;
/* Disallow all suspension. */
this->suspend_allowed_flags = 0;
/* Start termination. */
this->StartTermination();
/* Register the thread as a work task. */
KWorkerTaskManager::AddTask(KWorkerTaskManager::WorkerType_Exit, this);
}
MESOSPHERE_PANIC("KThread::Exit() would return");
}
Result KThread::Sleep(s64 timeout) {
MESOSPHERE_ASSERT_THIS();
MESOSPHERE_ASSERT(!KScheduler::IsSchedulerLockedByCurrentThread());
MESOSPHERE_ASSERT(this == GetCurrentThreadPointer());
MESOSPHERE_ASSERT(timeout > 0);
KHardwareTimer *timer;
{
/* Setup the scheduling lock and sleep. */
KScopedSchedulerLockAndSleep slp(std::addressof(timer), this, timeout);
/* Check if the thread should terminate. */
if (this->IsTerminationRequested()) {
slp.CancelSleep();
return svc::ResultTerminationRequested();
}
/* Mark the thread as waiting. */
this->SetState(KThread::ThreadState_Waiting);
}
/* The lock/sleep is done. */
/* Cancel the timer. */
timer->CancelTask(this);
return ResultSuccess();
}
void KThread::SetState(ThreadState state) {
MESOSPHERE_ASSERT_THIS();
KScopedSchedulerLock sl;
const ThreadState old_state = this->thread_state;
this->thread_state = static_cast<ThreadState>((old_state & ~ThreadState_Mask) | (state & ThreadState_Mask));
if (this->thread_state != old_state) {
KScheduler::OnThreadStateChanged(this, old_state);
}
}
KThreadContext *KThread::GetContextForSchedulerLoop() {
return std::addressof(this->GetContext());
}
}