Merge pull request #423 from DrChat/crash_pause

Pause Xenia if it crashes in guest code

src/xenia/base/exception_handler.h

@@ -0,0 +1,49 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2015 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_BASE_EXCEPTION_HANDLER_H_
+#define XENIA_BASE_EXCEPTION_HANDLER_H_
+
+#include <functional>
+#include <vector>
+
+namespace xe {
+class ExceptionHandler {
+ public:
+  struct Info {
+    enum {
+      kInvalidException = 0,
+      kAccessViolation,
+    } code = kInvalidException;
+
+    uint64_t pc = 0;  // Program counter address. RIP on x64.
+    uint64_t fault_address =
+        0;  // In case of AV, address that was read from/written to.
+
+    void* thread_context = nullptr;  // Platform-specific thread context info.
+  };
+  typedef std::function<bool(Info* ex_info)> Handler;
+
+  // Static initialization. Only call this once!
+  static bool Initialize();
+
+  // Install an exception handler. Returns an ID which you can save to remove
+  // this later. This will install the exception handler in the last place.
+  // TODO: ID support!
+  static uint32_t Install(Handler fn);
+  static bool Remove(uint32_t id);
+
+  static const std::vector<Handler>& handlers() { return handlers_; }
+
+ private:
+  static std::vector<Handler> handlers_;
+};
+};  // namespace xe
+
+#endif  // XENIA_BASE_EXCEPTION_HANDLER_H_

src/xenia/base/exception_handler_win.cc

@@ -0,0 +1,61 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2015 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include "xenia/base/exception_handler.h"
+
+#include "xenia/base/platform_win.h"
+
+namespace xe {
+std::vector<ExceptionHandler::Handler> ExceptionHandler::handlers_;
+
+LONG CALLBACK ExceptionHandlerCallback(PEXCEPTION_POINTERS ex_info) {
+  // Visual Studio SetThreadName
+  if (ex_info->ExceptionRecord->ExceptionCode == 0x406D1388) {
+    return EXCEPTION_CONTINUE_SEARCH;
+  }
+
+  auto code = ex_info->ExceptionRecord->ExceptionCode;
+  ExceptionHandler::Info info;
+  info.pc = ex_info->ContextRecord->Rip;
+  info.thread_context = ex_info->ContextRecord;
+
+  switch (code) {
+    case STATUS_ACCESS_VIOLATION:
+      info.code = ExceptionHandler::Info::kAccessViolation;
+      info.fault_address = ex_info->ExceptionRecord->ExceptionInformation[1];
+      break;
+  }
+
+  // Only call a handler if we support this type of exception.
+  if (info.code != ExceptionHandler::Info::kInvalidException) {
+    for (auto handler : ExceptionHandler::handlers()) {
+      if (handler(&info)) {
+        // Exception handled.
+        return EXCEPTION_CONTINUE_EXECUTION;
+      }
+    }
+  }
+
+  return EXCEPTION_CONTINUE_SEARCH;
+}
+
+bool ExceptionHandler::Initialize() {
+  AddVectoredExceptionHandler(0, ExceptionHandlerCallback);
+
+  // TODO: Do we need a continue handler if a debugger is attached?
+  return true;
+}
+
+uint32_t ExceptionHandler::Install(std::function<bool(Info* ex_info)> fn) {
+  handlers_.push_back(fn);
+
+  // TODO: ID support!
+  return 0;
+}
+}

src/xenia/emulator.cc

@@ -14,8 +14,11 @@
 #include "xenia/apu/audio_system.h"
 #include "xenia/base/assert.h"
 #include "xenia/base/clock.h"
+#include "xenia/base/debugging.h"
+#include "xenia/base/exception_handler.h"
 #include "xenia/base/logging.h"
 #include "xenia/base/string.h"
+#include "xenia/cpu/backend/code_cache.h"
 #include "xenia/gpu/graphics_system.h"
 #include "xenia/hid/input_system.h"
 #include "xenia/kernel/kernel_state.h"
@@ -27,6 +30,8 @@
 #include "xenia/vfs/devices/stfs_container_device.h"
 #include "xenia/vfs/virtual_file_system.h"
 
+#include "el/elements/message_form.h"
+
 DEFINE_double(time_scalar, 1.0,
               "Scalar used to speed or slow time (1x, 2x, 1/2x, etc).");
 
@@ -159,6 +164,11 @@ X_STATUS Emulator::Setup(ui::Window* display_window) {
     Profiler::set_display(std::move(profiler_display));
   });
 
+  // Install an exception handler.
+  ExceptionHandler::Initialize();
+  ExceptionHandler::Install(
+      std::bind(&Emulator::ExceptionCallback, this, std::placeholders::_1));
+
   return result;
 }
 
@@ -262,6 +272,64 @@ X_STATUS Emulator::LaunchStfsContainer(std::wstring path) {
   return CompleteLaunch(path, "game:\\default.xex");
 }
 
+bool Emulator::ExceptionCallback(ExceptionHandler::Info* info) {
+  // Check to see if the exception occurred in guest code.
+  auto code_cache = processor()->backend()->code_cache();
+  auto code_base = code_cache->base_address();
+  auto code_end = code_base + code_cache->total_size();
+
+  if (!debugger()->is_attached() && debugging::IsDebuggerAttached()) {
+    // If Xenia's debugger isn't attached but another one is, pass it to that
+    // debugger.
+    return false;
+  }
+
+  if (info->pc >= code_base && info->pc < code_end) {
+    using namespace xe::kernel;
+    auto global_lock = global_critical_region::AcquireDirect();
+
+    // Within range. Pause the emulator and eat the exception.
+    auto threads = kernel_state()->object_table()->GetObjectsByType<XThread>(
+        XObject::kTypeThread);
+    auto cur_thread = XThread::GetCurrentThread();
+    for (auto thread : threads) {
+      if (!thread->is_guest_thread()) {
+        // Don't pause host threads.
+        continue;
+      }
+
+      if (cur_thread == thread.get()) {
+        continue;
+      }
+
+      thread->Suspend(nullptr);
+    }
+
+    if (debugger()->is_attached()) {
+      // TODO: Send the exception to Xenia's debugger
+    }
+
+    // Display a dialog telling the user the guest has crashed.
+    display_window()->loop()->PostSynchronous([&]() {
+      auto msgbox = new el::elements::MessageForm(
+          display_window()->root_element(), "none");
+      msgbox->Show("Uh-oh!",
+                   "The guest has crashed.\n\n"
+                   "Xenia has now paused itself.");
+    });
+
+    // Now suspend ourself (we should be a guest thread).
+    cur_thread->Suspend(nullptr);
+
+    // We should not arrive here!
+    assert_always();
+    return false;
+  }
+
+  // Didn't occur in guest code. Let it pass.
+  return false;
+}
+
 X_STATUS Emulator::CompleteLaunch(const std::wstring& path,
                                   const std::string& module_path) {
   // Allow xam to request module loads.

src/xenia/emulator.h

@@ -12,6 +12,7 @@
 
 #include <string>
 
+#include "xenia/base/exception_handler.h"
 #include "xenia/debug/debugger.h"
 #include "xenia/kernel/kernel_state.h"
 #include "xenia/memory.h"
@@ -75,6 +76,8 @@ class Emulator {
   X_STATUS LaunchStfsContainer(std::wstring path);
 
  private:
+  bool ExceptionCallback(ExceptionHandler::Info* info);
+
   X_STATUS CompleteLaunch(const std::wstring& path,
                           const std::string& module_path);