Index: ntoskrnl/ex/sysinfo.c
===================================================================
--- ntoskrnl/ex/sysinfo.c	(revision 39187)
+++ ntoskrnl/ex/sysinfo.c	(working copy)
@@ -706,34 +706,104 @@
     PEPROCESS Process = NULL, SystemProcess;
     PETHREAD CurrentThread;
     ANSI_STRING ImageName;
-    int CurrentSize, ImageNameLength = 32; // image name len in bytes
+    int CurrentSize; 
+    USHORT ImageNameMaximumLength; // image name len in bytes
+    USHORT ImageNameLength;
     PLIST_ENTRY CurrentEntry;   
     ULONG TotalSize = 0, ThreadsCount;
     ULONG TotalUser, TotalKernel;
     PUCHAR Current;
     NTSTATUS Status = STATUS_SUCCESS;
+    UNICODE_STRING FileName;
+    PROS_SECTION_OBJECT SectionObject;
+    PWCHAR szSrc;
 
     _SEH2_TRY
     {
-        /* scan the process list */
+        /*20090229 Windows first test size. Only after writing to the buffer.
+         */
+        SystemProcess = PsIdleProcess;
+        Process = SystemProcess;
+        TotalSize = 0;
+        do //Debug trace value Windows
+        {
+            ThreadsCount = 0;
+            CurrentEntry = Process->ThreadListHead.Flink;
+            while (CurrentEntry != &Process->ThreadListHead)
+            {
+              ThreadsCount++;
+              CurrentEntry = CurrentEntry->Flink;
+            }
 
-        PSYSTEM_PROCESS_INFORMATION Spi
-            = (PSYSTEM_PROCESS_INFORMATION) Buffer;
+            ImageNameLength = 0;
+            SectionObject = Process->SectionObject;
+            if (SectionObject 
+                && SectionObject->FileObject
+                && SectionObject->FileObject->FileName.Buffer)
+            {
+              FileName = SectionObject->FileObject->FileName;
+              szSrc = (PWCHAR)((PCHAR)FileName.Buffer + FileName.Length);
+              /* Loop the file name*/
+              while (szSrc > FileName.Buffer)
+              {
+                if (*--szSrc == OBJ_NAME_PATH_SEPARATOR)
+                {
+                    szSrc++;
+                    break;
+                }
+                else
+                {
+                    ImageNameLength += sizeof(WCHAR);
+                }
+              }
+            }
+            if (!ImageNameLength && Process != PsIdleProcess && Process->ImageFileName)
+            {
+              ImageNameLength = strlen(Process->ImageFileName) * sizeof(WCHAR);
+            }
+            ImageNameMaximumLength = (ImageNameLength > 0 
+                 ? (ImageNameLength / 8 * 8 + ((ImageNameLength % 8) >= 0 ? 1 : 0)*8)
+                 : 0);
+            // size of the structure for every process
+            TotalSize += 
+              sizeof(SYSTEM_PROCESS_INFORMATION) + 
+              sizeof(SYSTEM_THREAD_INFORMATION) * ThreadsCount +
+              ImageNameMaximumLength;
 
-        *ReqSize = sizeof(SYSTEM_PROCESS_INFORMATION);
+            /* Handle idle process entry */
+            if (Process == PsIdleProcess) Process = NULL;
 
-        if (Size < sizeof(SYSTEM_PROCESS_INFORMATION))
+            Process = PsGetNextProcess(Process);
+            ThreadsCount = 0;
+            if ((Process == SystemProcess) || (Process == NULL))
+            {
+              break;
+            }
+        }  while ((Process != SystemProcess) && (Process != NULL));
+
+        *ReqSize = TotalSize;
+
+        if (Size < *ReqSize || Buffer == NULL)
         {
             _SEH2_YIELD(return STATUS_INFO_LENGTH_MISMATCH); // in case buffer size is too small
         }
-        RtlZeroMemory(Spi, Size);
 
-        SystemProcess = PsIdleProcess;
-        Process = SystemProcess;
-        Current = (PUCHAR) Spi;
+        if (Buffer != NULL)
+        {
+          TotalSize = 0;
+          /* scan the process list */
 
-        do
-        {
+          PSYSTEM_PROCESS_INFORMATION Spi
+            = (PSYSTEM_PROCESS_INFORMATION) Buffer;
+
+          RtlZeroMemory(Spi, Size);
+
+          SystemProcess = PsIdleProcess;
+          Process = SystemProcess;
+          Current = (PUCHAR) Spi;
+
+          do
+          {
             SpiCurrent = (PSYSTEM_PROCESS_INFORMATION) Current;
 
             ThreadsCount = 0;
@@ -746,7 +816,38 @@
 
             // size of the structure for every process
             CurrentSize = sizeof(SYSTEM_PROCESS_INFORMATION) + sizeof(SYSTEM_THREAD_INFORMATION) * ThreadsCount;
-            TotalSize += CurrentSize + ImageNameLength;
+            ImageNameLength = 0;
+            SectionObject = Process->SectionObject;
+            szSrc = NULL;
+            if (SectionObject 
+                && SectionObject->FileObject
+                && SectionObject->FileObject->FileName.Buffer)
+            {
+              FileName = SectionObject->FileObject->FileName;
+              szSrc = (PWCHAR)((PCHAR)FileName.Buffer + FileName.Length);
+              /* Loop the file name*/
+              while (szSrc > FileName.Buffer)
+              {
+                /* Make sure this isn't a backslash */
+                if (*--szSrc == OBJ_NAME_PATH_SEPARATOR)
+                {
+                    szSrc++;
+                    break;
+                }
+                else
+                {
+                    ImageNameLength += sizeof(WCHAR);
+                }
+              }
+            }
+            if (!ImageNameLength && Process != PsIdleProcess && Process->ImageFileName)
+            {
+              ImageNameLength = strlen(Process->ImageFileName) * sizeof(WCHAR);
+            }
+            ImageNameMaximumLength = (ImageNameLength > 0 
+                 ? (ImageNameLength / 8 * 8 + ((ImageNameLength % 8) >= 0 ? 1 : 0)*8)
+                 : 0);
+            TotalSize += CurrentSize + ImageNameMaximumLength;
 
             if (TotalSize > Size)
             {
@@ -757,18 +858,25 @@
             }
 
             // fill system information
-            SpiCurrent->NextEntryOffset = CurrentSize + ImageNameLength; // relative offset to the beginnnig of the next structure
+            SpiCurrent->NextEntryOffset = CurrentSize + ImageNameMaximumLength; // relative offset to the beginnnig of the next structure
             SpiCurrent->NumberOfThreads = ThreadsCount;
             SpiCurrent->CreateTime = Process->CreateTime;
-            SpiCurrent->ImageName.Length = strlen(Process->ImageFileName) * sizeof(WCHAR);
-            SpiCurrent->ImageName.MaximumLength = (USHORT)ImageNameLength;
+            SpiCurrent->ImageName.Length = ImageNameLength;
+            SpiCurrent->ImageName.MaximumLength = ImageNameMaximumLength;
             SpiCurrent->ImageName.Buffer = (void*)(Current + CurrentSize);
 
             // copy name to the end of the struct
             if(Process != PsIdleProcess)
             {
+              if (szSrc)
+              {
+                RtlCopyMemory(SpiCurrent->ImageName.Buffer, szSrc, SpiCurrent->ImageName.Length);
+              }
+              else if (Process->ImageFileName)
+              {
                 RtlInitAnsiString(&ImageName, Process->ImageFileName);
                 RtlAnsiStringToUnicodeString(&SpiCurrent->ImageName, &ImageName, FALSE);
+              }
             }
             else
             {
@@ -831,12 +939,13 @@
                 break;
             }
             else
-                Current += CurrentSize + ImageNameLength;
-        }  while ((Process != SystemProcess) && (Process != NULL));
+                Current += CurrentSize + ImageNameMaximumLength;
+          }  while ((Process != SystemProcess) && (Process != NULL));
 
-        if(Process != NULL)
+          if(Process != NULL)
             ObDereferenceObject(Process);
-        Status = STATUS_SUCCESS;
+          Status = STATUS_SUCCESS;
+        }
     }
     _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
     {