From a2bc0443f2beb113c95cee2b09577a87cf3a022c Mon Sep 17 00:00:00 2001
From: "Dr. Chat" <arkolbed@gmail.com>
Date: Mon, 7 Sep 2015 21:23:24 -0500
Subject: [PATCH] Quick-kill the MMIO handler if the fault address is above the
 mapping range.

---
 src/xenia/cpu/mmio_handler.cc | 9 ++++++---
 src/xenia/cpu/mmio_handler.h  | 4 +++-
 src/xenia/memory.cc           | 4 ++--
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/xenia/cpu/mmio_handler.cc b/src/xenia/cpu/mmio_handler.cc
index 5b704cf4d..0074eb595 100644
--- a/src/xenia/cpu/mmio_handler.cc
+++ b/src/xenia/cpu/mmio_handler.cc
@@ -25,7 +25,8 @@ std::unique_ptr<MMIOHandler> CreateMMIOHandler(uint8_t* virtual_membase,
                                                uint8_t* physical_membase);
 
 std::unique_ptr<MMIOHandler> MMIOHandler::Install(uint8_t* virtual_membase,
-                                                  uint8_t* physical_membase) {
+                                                  uint8_t* physical_membase,
+                                                  uint8_t* memory_end) {
   // There can be only one handler at a time.
   assert_null(global_handler_);
   if (global_handler_) {
@@ -40,6 +41,7 @@ std::unique_ptr<MMIOHandler> MMIOHandler::Install(uint8_t* virtual_membase,
     return nullptr;
   }
 
+  handler->memory_end_ = memory_end;
   global_handler_ = handler.get();
   return handler;
 }
@@ -364,8 +366,9 @@ bool TryDecodeMov(const uint8_t* p, DecodedMov* mov) {
 
 bool MMIOHandler::HandleAccessFault(void* thread_state,
                                     uint64_t fault_address) {
-  if (fault_address < uint64_t(virtual_membase_)) {
-    // Quick kill anything below our mapping base.
+  if (fault_address < uint64_t(virtual_membase_) ||
+      fault_address > uint64_t(memory_end_)) {
+    // Quick kill anything outside our mapping.
     return false;
   }
 
diff --git a/src/xenia/cpu/mmio_handler.h b/src/xenia/cpu/mmio_handler.h
index c8517fbb0..2d5b3fdde 100644
--- a/src/xenia/cpu/mmio_handler.h
+++ b/src/xenia/cpu/mmio_handler.h
@@ -42,7 +42,8 @@ class MMIOHandler {
   virtual ~MMIOHandler();
 
   static std::unique_ptr<MMIOHandler> Install(uint8_t* virtual_membase,
-                                              uint8_t* physical_membase);
+                                              uint8_t* physical_membase,
+                                              uint8_t* membase_end);
   static MMIOHandler* global_handler() { return global_handler_; }
 
   bool RegisterRange(uint32_t virtual_address, uint32_t mask, uint32_t size,
@@ -86,6 +87,7 @@ class MMIOHandler {
 
   uint8_t* virtual_membase_;
   uint8_t* physical_membase_;
+  uint8_t* memory_end_;
 
   std::vector<MMIORange> mapped_ranges_;
 
diff --git a/src/xenia/memory.cc b/src/xenia/memory.cc
index 7904a61ca..7485ece77 100644
--- a/src/xenia/memory.cc
+++ b/src/xenia/memory.cc
@@ -184,8 +184,8 @@ int Memory::Initialize() {
       kMemoryProtectRead | kMemoryProtectWrite);
 
   // Add handlers for MMIO.
-  mmio_handler_ =
-      cpu::MMIOHandler::Install(virtual_membase_, physical_membase_);
+  mmio_handler_ = cpu::MMIOHandler::Install(virtual_membase_, physical_membase_,
+                                            physical_membase_ + 0x1FFFFFFF);
   if (!mmio_handler_) {
     XELOGE("Unable to install MMIO handlers");
     assert_always();