Clean up TTD API

TitanEngine/Global.Engine.cpp

@@ -5,6 +5,7 @@
 #include "Global.Mapping.h"
 #include "Global.Engine.Hash.h"
 #include "Global.Debugger.h"
+#include <mutex>
 
 bool engineCheckForwarders = true;
 bool engineAlowModuleLoading = false;
@@ -20,6 +21,7 @@ bool engineSafeAttach = false;
 bool engineMembpAlt = false;
 bool engineDisableAslr = false;
 bool engineSafeStep = true;
+bool engineWow64SingleStepWorkaround = true;
 
 char engineFoundDLLName[512] = {0};
 char engineFoundAPIName[512] = {0};
@@ -30,6 +32,91 @@ LPVOID engineDependencyFiles;
 LPVOID engineDependencyFilesCWP;
 void* EngineStartUnpackingCallBack;
 
+namespace
+{
+std::mutex pauseMutex;
+LPVOID pauseCallback = nullptr;
+ULONGLONG pauseRequestTime = 0;
+ULONG_PTR pauseBreakInStart = 0;
+DWORD pauseBreakInThreadId = 0;
+bool pauseBreakInExpected = false;
+}
+
+bool EngineBeginPause(LPVOID Callback)
+{
+    std::lock_guard<std::mutex> lock(pauseMutex);
+    if(pauseCallback)
+        return false;
+    pauseCallback = Callback;
+    pauseRequestTime = GetTickCount64();
+    pauseBreakInStart = 0;
+    pauseBreakInThreadId = 0;
+    pauseBreakInExpected = false;
+    return true;
+}
+
+bool EnginePauseShouldEscalate(TitanPausePolicy MaximumPolicy)
+{
+    std::lock_guard<std::mutex> lock(pauseMutex);
+    return pauseCallback && !pauseBreakInExpected && MaximumPolicy == UE_PAUSE_POLICY_AGGRESSIVE &&
+           GetTickCount64() - pauseRequestTime >= 2000;
+}
+
+void EngineExpectPauseBreakIn(ULONG_PTR StartAddress)
+{
+    std::lock_guard<std::mutex> lock(pauseMutex);
+    pauseBreakInExpected = true;
+    pauseBreakInStart = StartAddress;
+    pauseBreakInThreadId = 0;
+}
+
+void EngineCancelPauseBreakIn()
+{
+    std::lock_guard<std::mutex> lock(pauseMutex);
+    pauseBreakInExpected = false;
+    pauseBreakInStart = 0;
+    pauseBreakInThreadId = 0;
+}
+
+void EngineObservePauseThread(DWORD ThreadId, ULONG_PTR StartAddress)
+{
+    std::lock_guard<std::mutex> lock(pauseMutex);
+    if(pauseBreakInExpected && pauseBreakInStart && StartAddress == pauseBreakInStart)
+        pauseBreakInThreadId = ThreadId;
+}
+
+bool EngineIsPauseBreakInEvent(DWORD ThreadId)
+{
+    std::lock_guard<std::mutex> lock(pauseMutex);
+    return pauseBreakInExpected && pauseBreakInThreadId && pauseBreakInThreadId == ThreadId;
+}
+
+void EngineCompletePause()
+{
+    LPVOID callback = nullptr;
+    {
+        std::lock_guard<std::mutex> lock(pauseMutex);
+        callback = pauseCallback;
+        pauseCallback = nullptr;
+        pauseRequestTime = 0;
+        pauseBreakInStart = 0;
+        pauseBreakInThreadId = 0;
+        pauseBreakInExpected = false;
+    }
+    if(callback)
+        ((void(TITCALL*)())callback)();
+}
+
+void EngineCancelPause()
+{
+    std::lock_guard<std::mutex> lock(pauseMutex);
+    pauseCallback = nullptr;
+    pauseRequestTime = 0;
+    pauseBreakInStart = 0;
+    pauseBreakInThreadId = 0;
+    pauseBreakInExpected = false;
+}
+
 // Global.Engine.functions:
 void EngineInit()
 {

TitanEngine/Global.Engine.h

@@ -23,10 +23,19 @@ extern bool engineSafeAttach;
 extern bool engineMembpAlt;
 extern bool engineDisableAslr;
 extern bool engineSafeStep;
+extern bool engineWow64SingleStepWorkaround;
 
 //Global.Engine.Functions
 void EngineInit();
 bool EngineIsThereFreeHardwareBreakSlot(LPDWORD FreeRegister);
+bool EngineBeginPause(LPVOID Callback);
+bool EnginePauseShouldEscalate(TitanPausePolicy MaximumPolicy);
+void EngineExpectPauseBreakIn(ULONG_PTR StartAddress);
+void EngineCancelPauseBreakIn();
+void EngineObservePauseThread(DWORD ThreadId, ULONG_PTR StartAddress);
+bool EngineIsPauseBreakInEvent(DWORD ThreadId);
+void EngineCompletePause();
+void EngineCancelPause();
 bool EngineFileExists(char* szFileName);
 void EngineCreatePathForFile(char* szFileName);
 void EngineCreatePathForFileW(wchar_t* szFileName);

TitanEngine/TitanEngine.Debugger.Control.cpp

@@ -38,6 +38,27 @@ __declspec(dllexport) void TITCALL ForceClose()
 
 __declspec(dllexport) void TITCALL StepInto(LPVOID StepCallBack)
 {
+#ifndef _WIN64
+    // A WOW64 transition through `ljmp 33h` cannot be completed reliably with
+    // the x86 trap flag. Treat the return address already on the x86 stack as
+    // an engine-owned one-shot step target instead. The frontend only requests
+    // StepInto and does not need to know which execution mechanism is used.
+    if(engineWow64SingleStepWorkaround)
+    {
+        unsigned char data[7] = {};
+        auto cip = GetContextData(UE_CIP);
+        if(MemoryReadSafe(dbgProcessInformation.hProcess, (void*)cip, data, sizeof(data), nullptr) &&
+                data[0] == 0xEA && data[5] == 0x33 && data[6] == 0x00)
+        {
+            ULONG_PTR returnAddress = 0;
+            auto csp = GetContextData(UE_CSP);
+            if(MemoryReadSafe(dbgProcessInformation.hProcess, (void*)csp, &returnAddress,
+                              sizeof(returnAddress), nullptr) &&
+                    SetBPX(returnAddress, UE_SINGLESHOOT, StepCallBack))
+                return;
+        }
+    }
+#endif
     EnterCriticalSection(&engineStepActiveCr);
     // Arm a single-step for the current event thread only. State is per-thread, so a
     // step already pending on another thread does not block this one.

TitanEngine/TitanEngine.Debugger.Data.cpp

@@ -175,7 +175,8 @@ __declspec(dllexport) bool TITCALL GetSessionInfo(TITAN_SESSION_INFO* SessionInf
                                 UE_SESSION_CAP_CONTEXT_READ | UE_SESSION_CAP_FORWARD_EXECUTION |
                                 UE_SESSION_CAP_MEMORY_WRITE | UE_SESSION_CAP_CONTEXT_WRITE |
                                 UE_SESSION_CAP_PROCESS_CONTROL | UE_SESSION_CAP_THREAD_CONTROL |
-                                UE_SESSION_CAP_NATIVE_HANDLES | UE_SESSION_CAP_EXCEPTION_CONTINUE;
+                                UE_SESSION_CAP_NATIVE_HANDLES | UE_SESSION_CAP_EXCEPTION_CONTINUE |
+                                UE_SESSION_CAP_PAUSE_EXECUTION;
 #ifdef _WIN64
     SessionInfo->machineType = IMAGE_FILE_MACHINE_AMD64;
 #else
@@ -210,13 +211,13 @@ __declspec(dllexport) bool TITCALL ReplaySetPosition(const TITAN_REPLAY_POSITION
     return false;
 }
 
-__declspec(dllexport) bool TITCALL ReplayRun(bool Reverse)
+__declspec(dllexport) bool TITCALL ReplayRunBack()
 {
     SetLastError(ERROR_NOT_SUPPORTED);
     return false;
 }
 
-__declspec(dllexport) bool TITCALL ReplayStep(bool Reverse, bool StepOver, TITANCBSTEP StepCallBack)
+__declspec(dllexport) bool TITCALL ReplayStepBack(TITANCBSTEP StepCallBack)
 {
     SetLastError(ERROR_NOT_SUPPORTED);
     return false;

TitanEngine/TitanEngine.Debugger.DebugLoop.cpp

@@ -69,6 +69,7 @@ static void engineStep()
 
 __declspec(dllexport) void TITCALL DebugLoop()
 {
+    EngineCancelPause();
     bool FirstBPX = true;
     bool ResetBPX = false;
     bool PushfBPX = false;
@@ -375,6 +376,8 @@ __declspec(dllexport) void TITCALL DebugLoop()
             NewThreadData.ThreadStartAddress = (void*)DBGEvent.u.CreateThread.lpStartAddress;
             NewThreadData.ThreadLocalBase = (void*)DBGEvent.u.CreateThread.lpThreadLocalBase;
             hListThread.push_back(NewThreadData);
+            EngineObservePauseThread(DBGEvent.dwThreadId,
+                                     (ULONG_PTR)DBGEvent.u.CreateThread.lpStartAddress);
 
             //Set hardware breakpoints to all threads
             HANDLE hThread = NewThreadData.hThread;
@@ -588,6 +591,15 @@ __declspec(dllexport) void TITCALL DebugLoop()
         {
             DBGCode = DBG_EXCEPTION_NOT_HANDLED; //let the debuggee handle exceptions per default
 
+            if((DBGEvent.u.Exception.ExceptionRecord.ExceptionCode == STATUS_BREAKPOINT ||
+                    DBGEvent.u.Exception.ExceptionRecord.ExceptionCode == STATUS_WX86_BREAKPOINT) &&
+                    EngineIsPauseBreakInEvent(DBGEvent.dwThreadId))
+            {
+                DBGCode = DBG_CONTINUE;
+                EngineCompletePause();
+                break;
+            }
+
             if(DBGCustomHandler->chEverythingElse != NULL)
             {
                 myCustomHandler = (fCustomHandler)((LPVOID)DBGCustomHandler->chEverythingElse);
@@ -1490,6 +1502,7 @@ continue_dbg_event:
     {
         RtlMoveMemory(&TerminateDBGEvent, &DBGEvent, sizeof(DEBUG_EVENT));
     }
+    EngineCancelPause();
     ForceClose();
     engineFileIsBeingDebugged = false;
     DebuggerReset();

TitanEngine/TitanEngine.Engine.cpp

@@ -55,6 +55,10 @@ __declspec(dllexport) void TITCALL SetEngineVariable(DWORD VariableId, bool Vari
     {
         engineSafeStep = VariableSet;
     }
+    else if(VariableId == UE_ENGINE_WOW64_SINGLE_STEP_WORKAROUND)
+    {
+        engineWow64SingleStepWorkaround = VariableSet;
+    }
 }
 
 __declspec(dllexport) bool TITCALL EngineCreateMissingDependencies(char* szFileName, char* szOutputFolder, bool LogCreatedFiles)

TitanEngine/TitanEngine.Process.cpp

@@ -2,6 +2,8 @@
 #include "definitions.h"
 #include "Global.Handle.h"
 #include "Global.Engine.h"
+#include "Global.Debugger.h"
+#include <TlHelp32.h>
 
 // TitanEngine.Process.functions:
 __declspec(dllexport) long TITCALL GetActiveProcessId(char* szImageName)
@@ -178,9 +180,115 @@ __declspec(dllexport) bool TITCALL TitanTerminateProcess(HANDLE hProcess, DWORD
     return !!TerminateProcess(hProcess, exitCode);
 }
 
-__declspec(dllexport) bool TITCALL TitanDebugBreakProcess(HANDLE hProcess)
+static ULONG_PTR pauseBreakInStartAddress()
 {
-    return !!DebugBreakProcess(hProcess);
+    auto localNtdll = GetModuleHandleW(L"ntdll.dll");
+    auto localStart = localNtdll ? GetProcAddress(localNtdll, "DbgUiRemoteBreakin") : nullptr;
+    if(!localStart || !dbgProcessInformation.dwProcessId)
+        return 0;
+
+    auto snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE | TH32CS_SNAPMODULE32,
+                                             dbgProcessInformation.dwProcessId);
+    if(snapshot == INVALID_HANDLE_VALUE)
+        return 0;
+    MODULEENTRY32W module = {};
+    module.dwSize = sizeof(module);
+    ULONG_PTR result = 0;
+    if(Module32FirstW(snapshot, &module))
+    {
+        do
+        {
+            if(!_wcsicmp(module.szModule, L"ntdll.dll"))
+            {
+                result = (ULONG_PTR)module.modBaseAddr +
+                         (ULONG_PTR)localStart - (ULONG_PTR)localNtdll;
+                break;
+            }
+        }
+        while(Module32NextW(snapshot, &module));
+    }
+    CloseHandle(snapshot);
+    return result;
+}
+
+static bool requestPauseBreakIn()
+{
+    auto startAddress = pauseBreakInStartAddress();
+    if(!startAddress)
+    {
+        SetLastError(ERROR_PROC_NOT_FOUND);
+        return false;
+    }
+    EngineExpectPauseBreakIn(startAddress);
+    if(DebugBreakProcess(dbgProcessInformation.hProcess))
+        return true;
+    EngineCancelPauseBreakIn();
+    return false;
+}
+
+__declspec(dllexport) bool TITCALL RequestPause(TitanPausePolicy MaximumPolicy, TITANCBPAUSE PauseCallback)
+{
+    if(MaximumPolicy < UE_PAUSE_POLICY_NONINVASIVE || MaximumPolicy > UE_PAUSE_POLICY_AGGRESSIVE ||
+       !PauseCallback || !engineFileIsBeingDebugged || !dbgProcessInformation.hProcess)
+    {
+        SetLastError(ERROR_INVALID_PARAMETER);
+        return false;
+    }
+
+    if(!EngineBeginPause((LPVOID)PauseCallback))
+    {
+        if(EnginePauseShouldEscalate(MaximumPolicy))
+            requestPauseBreakIn(); // The original, less intrusive request remains pending on failure.
+        return true;
+    }
+
+    if(MaximumPolicy == UE_PAUSE_POLICY_NONINVASIVE)
+    {
+        EngineCancelPause();
+        SetLastError(ERROR_NOT_SUPPORTED);
+        return false;
+    }
+
+    auto threadId = DebugAttachedToProcess || !DBGEvent.dwThreadId
+                    ? dbgProcessInformation.dwThreadId
+                    : DBGEvent.dwThreadId;
+    auto thread = EngineOpenThread(THREAD_GETSETSUSPEND, false, threadId);
+    if(!thread)
+    {
+        if(MaximumPolicy == UE_PAUSE_POLICY_AGGRESSIVE && requestPauseBreakIn())
+            return true;
+        EngineCancelPause();
+        return false;
+    }
+
+    auto previousSuspendCount = SuspendThread(thread);
+    if(previousSuspendCount != 0)
+    {
+        if(previousSuspendCount != (DWORD)-1)
+            ResumeThread(thread);
+        EngineCloseHandle(thread);
+        if(MaximumPolicy == UE_PAUSE_POLICY_AGGRESSIVE && requestPauseBreakIn())
+            return true;
+        EngineCancelPause();
+        SetLastError(ERROR_BUSY);
+        return false;
+    }
+
+    auto cip = GetContextDataEx(thread, UE_CIP);
+    auto armed = cip && SetBPX(cip, UE_SINGLESHOOT, (LPVOID)&EngineCompletePause);
+    if(armed)
+        PostThreadMessageW(threadId, WM_NULL, 0, 0);
+    auto resumed = ResumeThread(thread) != (DWORD)-1;
+    EngineCloseHandle(thread);
+    if(armed && resumed)
+        return true;
+    if(armed)
+        DeleteBPX(cip);
+
+    if(MaximumPolicy == UE_PAUSE_POLICY_AGGRESSIVE && requestPauseBreakIn())
+        return true;
+    EngineCancelPause();
+    return false;
 }
 
 __declspec(dllexport) HANDLE TITCALL TitanCreateRemoteThread(HANDLE hProcess, LPTHREAD_START_ROUTINE start, LPVOID argument, DWORD creationFlags, LPDWORD threadId)

TitanEngine/TitanEngine.def

@@ -92,8 +92,8 @@ GetSessionInfo
 ReplayGetPosition
 ReplayGetExtent
 ReplaySetPosition
-ReplayRun
+ReplayRunBack
-ReplayStep
+ReplayStepBack
 InitNativeDebug
 InitNativeDebugW
 InitDebugEx
@@ -406,7 +406,7 @@ TitanGetModulePathW
 TitanCloseHandle
 ProcessIsWow64
 TitanTerminateProcess
-TitanDebugBreakProcess
+RequestPause
 TitanCreateRemoteThread
 TitanSuspendThread
 TitanResumeThread

TitanEngine/definitions.h

@@ -171,8 +171,8 @@ __declspec(dllexport) bool TITCALL GetSessionInfo(TITAN_SESSION_INFO* SessionInf
 __declspec(dllexport) bool TITCALL ReplayGetPosition(TITAN_REPLAY_POSITION* Position);
 __declspec(dllexport) bool TITCALL ReplayGetExtent(TITAN_REPLAY_POSITION* First, TITAN_REPLAY_POSITION* Last);
 __declspec(dllexport) bool TITCALL ReplaySetPosition(const TITAN_REPLAY_POSITION* Position);
-__declspec(dllexport) bool TITCALL ReplayRun(bool Reverse);
+__declspec(dllexport) bool TITCALL ReplayRunBack();
-__declspec(dllexport) bool TITCALL ReplayStep(bool Reverse, bool StepOver, TITANCBSTEP StepCallBack);
+__declspec(dllexport) bool TITCALL ReplayStepBack(TITANCBSTEP StepCallBack);
 __declspec(dllexport) void* TITCALL InitNativeDebug(char* szFileName, char* szCommandLine, char* szCurrentFolder);
 __declspec(dllexport) void* TITCALL InitNativeDebugW(wchar_t* szFileName, wchar_t* szCommandLine, wchar_t* szCurrentFolder);
 __declspec(dllexport) void* TITCALL InitDebugEx(char* szFileName, char* szCommandLine, char* szCurrentFolder, LPVOID EntryCallBack);
@@ -372,7 +372,7 @@ __declspec(dllexport) bool TITCALL TitanGetModulePathW(HANDLE hProcess, ULONG_PT
 __declspec(dllexport) bool TITCALL TitanCloseHandle(HANDLE hEngineHandle);
 __declspec(dllexport) bool TITCALL ProcessIsWow64(HANDLE hProcess, PBOOL isWow64);
 __declspec(dllexport) bool TITCALL TitanTerminateProcess(HANDLE hProcess, DWORD exitCode);
-__declspec(dllexport) bool TITCALL TitanDebugBreakProcess(HANDLE hProcess);
+__declspec(dllexport) bool TITCALL RequestPause(TitanPausePolicy MaximumPolicy, TITANCBPAUSE PauseCallback);
 __declspec(dllexport) HANDLE TITCALL TitanCreateRemoteThread(HANDLE hProcess, LPTHREAD_START_ROUTINE start, LPVOID argument, DWORD creationFlags, LPDWORD threadId);
 __declspec(dllexport) DWORD TITCALL TitanSuspendThread(HANDLE hThread);
 __declspec(dllexport) DWORD TITCALL TitanResumeThread(HANDLE hThread);

TitanEngine/stdafx.h

@@ -34,6 +34,7 @@
 #include <stdint.h>
 
 typedef void(*TITANCBSTEP)();
+typedef void(*TITANCBPAUSE)();
 
 #ifndef _Out_writes_opt_
 #define _Out_writes_opt_(x)
@@ -155,6 +156,8 @@ enum TitanSessionCapability : uint64_t
     UE_SESSION_CAP_NATIVE_HANDLES = 1ull << 12,
     UE_SESSION_CAP_EXCEPTION_CONTINUE = 1ull << 13,
     UE_SESSION_CAP_TIMELINE_STATE = 1ull << 14,
+    UE_SESSION_CAP_PAUSE_EXECUTION = 1ull << 16,
+    UE_SESSION_CAP_NAVIGABLE_PROCESS_EXIT = 1ull << 17,
 };
 
 typedef struct
@@ -559,6 +562,14 @@ typedef struct HOOK_ENTRY
 #define UE_ENGINE_MEMBP_ALT 11
 #define UE_ENGINE_DISABLE_ASLR 12
 #define UE_ENGINE_SAFE_STEP 13
+#define UE_ENGINE_WOW64_SINGLE_STEP_WORKAROUND 14
+
+enum TitanPausePolicy
+{
+    UE_PAUSE_POLICY_NONINVASIVE = 0,
+    UE_PAUSE_POLICY_STANDARD = 1,
+    UE_PAUSE_POLICY_AGGRESSIVE = 2,
+};
 
 #define UE_OPTION_REMOVEALL 1
 #define UE_OPTION_DISABLEALL 2