From 621d3f8abb336a370859aa7fe3ff6d6cc9ae6eaa Mon Sep 17 00:00:00 2001
From: "Dr. Chat" <arkolbed@gmail.com>
Date: Mon, 14 Dec 2015 14:34:44 -0600
Subject: [PATCH] XThread free stack on destruction

---
 src/xenia/kernel/xthread.cc | 15 ++++++++++++++-
 src/xenia/kernel/xthread.h  |  1 +
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/xenia/kernel/xthread.cc b/src/xenia/kernel/xthread.cc
index ca0fe1a8c..8056878c4 100644
--- a/src/xenia/kernel/xthread.cc
+++ b/src/xenia/kernel/xthread.cc
@@ -89,6 +89,7 @@ XThread::~XThread() {
   kernel_state()->memory()->SystemHeapFree(scratch_address_);
   kernel_state()->memory()->SystemHeapFree(tls_address_);
   kernel_state()->memory()->SystemHeapFree(pcr_address_);
+  FreeStack();
 
   if (thread_) {
     // TODO(benvanik): platform kill
@@ -214,7 +215,7 @@ bool XThread::AllocateStack(uint32_t size) {
   auto heap = memory()->LookupHeap(0x40000000);
 
   auto alignment = heap->page_size();
-  auto padding = heap->page_size() * 2;  // Guard pages
+  auto padding = heap->page_size() * 2;  // Guard page size * 2
   size = xe::round_up(size, alignment);
   auto actual_size = size + padding;
 
@@ -241,6 +242,18 @@ bool XThread::AllocateStack(uint32_t size) {
   return true;
 }
 
+void XThread::FreeStack() {
+  if (stack_alloc_base_) {
+    auto heap = memory()->LookupHeap(0x40000000);
+    heap->Release(stack_alloc_base_);
+
+    stack_alloc_base_ = 0;
+    stack_alloc_size_ = 0;
+    stack_base_ = 0;
+    stack_limit_ = 0;
+  }
+}
+
 X_STATUS XThread::Create() {
   // Thread kernel object.
   if (!CreateNative<X_KTHREAD>()) {
diff --git a/src/xenia/kernel/xthread.h b/src/xenia/kernel/xthread.h
index c145ed0e5..2ccc0d15b 100644
--- a/src/xenia/kernel/xthread.h
+++ b/src/xenia/kernel/xthread.h
@@ -196,6 +196,7 @@ class XThread : public XObject {
 
  protected:
   bool AllocateStack(uint32_t size);
+  void FreeStack();
   void InitializeGuestObject();
 
   bool StepToAddress(uint32_t pc);