- implemented MemoryWriteSafe

- renamed FilterBreakPoints
- fixed a bug in EnableBPX (now it re-reads the original bytes)

TitanEngine/Global.Breakpoints.cpp

@@ -111,8 +111,9 @@ void uintdr7(ULONG_PTR dr7, DR7* ret)
         BITSET(ret->HWBP_SIZE[3],1);
 }
 
-void FilterBreakPoints(ULONG_PTR lpBaseAddress, unsigned char* lpBuffer, SIZE_T nSize)
+void BreakPointPostReadFilter(ULONG_PTR lpBaseAddress, unsigned char* lpBuffer, SIZE_T nSize)
 {
+    MutexLocker lock("BreakPointBuffer");
     ULONG_PTR start=lpBaseAddress;
     ULONG_PTR end=start+nSize;
     int bpcount=BreakPointBuffer.size();
@@ -120,7 +121,7 @@ void FilterBreakPoints(ULONG_PTR lpBaseAddress, unsigned char* lpBuffer, SIZE_T
     {
         BreakPointDetail* curBp=&BreakPointBuffer.at(i);
         //check if the breakpoint is one we should be concerned about
-        if(!curBp->BreakPointActive || (curBp->BreakPointType != UE_BREAKPOINT && curBp->BreakPointType != UE_SINGLESHOOT))
+        if(curBp->BreakPointActive != UE_BPXINACTIVE || (curBp->BreakPointType != UE_BREAKPOINT && curBp->BreakPointType != UE_SINGLESHOOT))
             continue;
         ULONG_PTR cur_addr=curBp->BreakPointAddress;
         if(cur_addr>=start && cur_addr<end) //breakpoint is in range
@@ -133,3 +134,47 @@ void FilterBreakPoints(ULONG_PTR lpBaseAddress, unsigned char* lpBuffer, SIZE_T
         }
     }
 }
+
+void BreakPointPreWriteFilter(ULONG_PTR lpBaseAddress, SIZE_T nSize, MutexLocker* lock)
+{
+    ULONG_PTR start=lpBaseAddress;
+    ULONG_PTR end=start+nSize;
+    int bpcount=BreakPointBuffer.size();
+    for(int i=0; i<bpcount; i++)
+    {
+        BreakPointDetail* curBp=&BreakPointBuffer.at(i);
+        //check if the breakpoint is one we should be concerned about
+        if(curBp->BreakPointActive != UE_BPXINACTIVE || (curBp->BreakPointType != UE_BREAKPOINT && curBp->BreakPointType != UE_SINGLESHOOT))
+            continue;
+        ULONG_PTR cur_addr=curBp->BreakPointAddress;
+        if(cur_addr>=start && cur_addr<end) //breakpoint is in range
+        {
+            lock->unlock();
+            DisableBPX(cur_addr); //needs a cleaner solution
+            lock->relock();
+            curBp->BreakPointActive = UE_BPXACTIVE; //little hack
+        }
+    }
+}
+
+void BreakPointPostWriteFilter(ULONG_PTR lpBaseAddress, SIZE_T nSize, MutexLocker* lock)
+{
+    ULONG_PTR start=lpBaseAddress;
+    ULONG_PTR end=start+nSize;
+    int bpcount=BreakPointBuffer.size();
+    for(int i=0; i<bpcount; i++)
+    {
+        BreakPointDetail* curBp=&BreakPointBuffer.at(i);
+        //check if the breakpoint is one we should be concerned about
+        if(curBp->BreakPointActive != UE_BPXINACTIVE || (curBp->BreakPointType != UE_BREAKPOINT && curBp->BreakPointType != UE_SINGLESHOOT))
+            continue;
+        ULONG_PTR cur_addr=curBp->BreakPointAddress;
+        if(cur_addr>=start && cur_addr<end) //breakpoint is in range
+        {
+            curBp->BreakPointActive = UE_BPXINACTIVE; //little hack
+            lock->unlock();
+            EnableBPX(cur_addr); //needs a cleaner solution
+            lock->relock();
+        }
+    }
+}

TitanEngine/Global.Breakpoints.h

@@ -2,11 +2,14 @@
 #define _GLOBAL_BREAKPOINTS_H
 
 #include <vector>
+#include "Global.Engine.Threading.h"
 
 extern std::vector<BreakPointDetail> BreakPointBuffer;
 
 void uintdr7(ULONG_PTR dr7, DR7* ret);
 ULONG_PTR dr7uint(DR7* dr7);
-void FilterBreakPoints(ULONG_PTR lpBaseAddress, unsigned char* lpBuffer, SIZE_T nSize);
+void BreakPointPostReadFilter(ULONG_PTR lpBaseAddress, unsigned char* lpBuffer, SIZE_T nSize);
+void BreakPointPreWriteFilter(ULONG_PTR lpBaseAddress, SIZE_T nSize, MutexLocker* lock);
+void BreakPointPostWriteFilter(ULONG_PTR lpBaseAddress, SIZE_T nSize, MutexLocker* lock);
 
 #endif //_GLOBAL_BREAKPOINTS_H

TitanEngine/TitanEngine.Breakpoints.cpp

@@ -66,6 +66,9 @@ __declspec(dllexport) bool TITCALL EnableBPX(ULONG_PTR bpxAddress)
             OldProtect = MemInfo.Protect;
             VirtualProtectEx(dbgProcessInformation.hProcess, (LPVOID)bpxAddress, BreakPointBuffer.at(i).BreakPointSize, PAGE_EXECUTE_READWRITE, &OldProtect);
             if(BreakPointBuffer.at(i).BreakPointActive == UE_BPXINACTIVE && (BreakPointBuffer.at(i).BreakPointType == UE_BREAKPOINT || BreakPointBuffer.at(i).BreakPointType == UE_SINGLESHOOT))
+            {
+                //re-read original byte(s)
+                if(ReadProcessMemory(dbgProcessInformation.hProcess, (LPVOID)bpxAddress, BreakPointBuffer.at(i).OriginalByte, BreakPointBuffer.at(i).BreakPointSize, 0))
                 {
                     if(BreakPointBuffer.at(i).AdvancedBreakPointType == UE_BREAKPOINT_INT3)
                     {
@@ -106,6 +109,12 @@ __declspec(dllexport) bool TITCALL EnableBPX(ULONG_PTR bpxAddress)
                     return false;
                 }
             }
+            else
+            {
+                VirtualProtectEx(dbgProcessInformation.hProcess, (LPVOID)bpxAddress, BreakPointBuffer.at(i).BreakPointSize, OldProtect, &OldProtect);
+                return false;
+            }
+        }
     }
     return false;
 }

TitanEngine/TitanEngine.Debugger.Memory.cpp

@@ -402,7 +402,7 @@ __declspec(dllexport) bool TITCALL MemoryReadSafe(HANDLE hProcess, LPVOID lpBase
 
     //filter breakpoints
     if(retValue)
-        FilterBreakPoints((ULONG_PTR)lpBaseAddress, (unsigned char*)lpBuffer, nSize);
+        BreakPointPostReadFilter((ULONG_PTR)lpBaseAddress, (unsigned char*)lpBuffer, nSize);
 
     return retValue;
 }
@@ -412,5 +412,48 @@ __declspec(dllexport) bool TITCALL MemoryReadSafe(HANDLE hProcess, LPVOID lpBase
 //- re-set breakpoints when overwritten
 __declspec(dllexport) bool TITCALL MemoryWriteSafe(HANDLE hProcess, LPVOID lpBaseAddress, LPCVOID lpBuffer, SIZE_T nSize, SIZE_T * lpNumberOfBytesWritten)
 {
-    return !!WriteProcessMemory(hProcess, lpBaseAddress, lpBuffer, nSize, lpNumberOfBytesWritten);
+    SIZE_T ueNumberOfBytesWritten = 0;
+    SIZE_T * pNumBytes = 0;
+    DWORD dwProtect = 0;
+    bool retValue = false;
+
+    //read memory
+    if ( (hProcess == 0) || (lpBaseAddress == 0) ||  (lpBuffer == 0) || (nSize == 0))
+    {
+        return false;
+    }
+
+    MutexLocker lock("BreakPointBuffer"); //thread-safe
+    //disable breakpoints that interfere with the memory to write
+    BreakPointPreWriteFilter((ULONG_PTR)lpBaseAddress, nSize, &lock);
+
+    if (!lpNumberOfBytesWritten)
+    {
+        pNumBytes = &ueNumberOfBytesWritten;
+    }
+    else
+    {
+        pNumBytes = lpNumberOfBytesWritten;
+    }
+
+    if(!WriteProcessMemory(hProcess, lpBaseAddress, lpBuffer, nSize, pNumBytes))
+    {
+        if (VirtualProtectEx(hProcess, lpBaseAddress, nSize, PAGE_EXECUTE_READWRITE, &dwProtect))
+        {
+            if (WriteProcessMemory(hProcess, lpBaseAddress, lpBuffer, nSize, pNumBytes))
+            {
+                retValue = true;
+            }
+            VirtualProtectEx(hProcess, lpBaseAddress, nSize, dwProtect, &dwProtect);
+        }
+    }
+    else
+    {
+        retValue = true;
+    }
+
+    //re-enable breakpoints that interfere with the memory to write
+    BreakPointPostWriteFilter((ULONG_PTR)lpBaseAddress, nSize, &lock);
+
+    return retValue;
 }