[NTOS]: Fix Implementation of BreakOnTermination -- Process Flags should be accessed...
[reactos.git] / reactos / ntoskrnl / ps / query.c
index 6dc195c..342c818 100644 (file)
@@ -5,6 +5,7 @@
  * PURPOSE:         Process Manager: Thread/Process Query/Set Information
  * PROGRAMMERS:     Alex Ionescu (alex.ionescu@reactos.org)
  *                  Thomas Weidenmueller (w3seek@reactos.org)
+ *                  Eric Kohl
  */
 
 /* INCLUDES ******************************************************************/
@@ -63,7 +64,7 @@ NtQueryInformationProcess(IN HANDLE ProcessHandle,
 {
     PEPROCESS Process;
     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
-    NTSTATUS Status = STATUS_SUCCESS;
+    NTSTATUS Status;
     ULONG Length = 0;
     PPROCESS_BASIC_INFORMATION ProcessBasicInfo =
         (PPROCESS_BASIC_INFORMATION)ProcessInformation;
@@ -74,22 +75,33 @@ NtQueryInformationProcess(IN HANDLE ProcessHandle,
         (PPROCESS_SESSION_INFORMATION)ProcessInformation;
     PVM_COUNTERS VmCounters = (PVM_COUNTERS)ProcessInformation;
     PIO_COUNTERS IoCounters = (PIO_COUNTERS)ProcessInformation;
+    PQUOTA_LIMITS QuotaLimits = (PQUOTA_LIMITS)ProcessInformation;
     PROCESS_DEVICEMAP_INFORMATION DeviceMap;
     PUNICODE_STRING ImageName;
     ULONG Cookie;
     PAGED_CODE();
 
-    /* Check validity of Information Class */
-#if 0
-    Status = DefaultQueryInfoBufferCheck(ProcessInformationClass,
-                                         PsProcessInfoClass,
-                                         RTL_NUMBER_OF(PsProcessInfoClass),
-                                         ProcessInformation,
-                                         ProcessInformationLength,
-                                         ReturnLength,
-                                         PreviousMode);
-    if (!NT_SUCCESS(Status)) return Status;
-#endif
+    /* Check for user-mode caller */
+    if (PreviousMode != KernelMode)
+    {
+        /* Prepare to probe parameters */
+        _SEH2_TRY
+        {
+            /* Probe the buffer */
+            ProbeForWrite(ProcessInformation,
+                          ProcessInformationLength,
+                          sizeof(ULONG));
+
+            /* Probe the return length if required */
+            if (ReturnLength) ProbeForWriteUlong(ReturnLength);
+        }
+        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+        {
+            /* Return the exception code */
+            _SEH2_YIELD(return _SEH2_GetExceptionCode());
+        }
+        _SEH2_END;
+    }
 
     if((ProcessInformationClass == ProcessCookie) &&
         (ProcessHandle != NtCurrentProcess()))
@@ -151,7 +163,7 @@ NtQueryInformationProcess(IN HANDLE ProcessHandle,
             ObDereferenceObject(Process);
             break;
 
-        /* Quote limits: not implemented */
+        /* Process quota limits */
         case ProcessQuotaLimits:
 
             Length = sizeof(QUOTA_LIMITS);
@@ -170,8 +182,46 @@ NtQueryInformationProcess(IN HANDLE ProcessHandle,
                                                NULL);
             if (!NT_SUCCESS(Status)) break;
 
-            /* TODO: Implement this case */
-            Status = STATUS_NOT_IMPLEMENTED;
+            /* Indicate success */
+            Status = STATUS_SUCCESS;
+
+            _SEH2_TRY
+            {
+                /* Set max/min working set sizes */
+                QuotaLimits->MaximumWorkingSetSize =
+                        Process->Vm.MaximumWorkingSetSize << PAGE_SHIFT;
+                QuotaLimits->MinimumWorkingSetSize =
+                        Process->Vm.MinimumWorkingSetSize << PAGE_SHIFT;
+
+                /* Set default time limits */
+                QuotaLimits->TimeLimit.LowPart = MAXULONG;
+                QuotaLimits->TimeLimit.HighPart = MAXULONG;
+
+                /* Is quota block a default one? */
+                if (Process->QuotaBlock == &PspDefaultQuotaBlock)
+                {
+                    /* Set default pools and pagefile limits */
+                    QuotaLimits->PagedPoolLimit = (SIZE_T)-1;
+                    QuotaLimits->NonPagedPoolLimit = (SIZE_T)-1;
+                    QuotaLimits->PagefileLimit = (SIZE_T)-1;
+                }
+                else
+                {
+                    /* Get limits from non-default quota block */
+                    QuotaLimits->PagedPoolLimit =
+                        Process->QuotaBlock->QuotaEntry[PagedPool].Limit;
+                    QuotaLimits->NonPagedPoolLimit =
+                        Process->QuotaBlock->QuotaEntry[NonPagedPool].Limit;
+                    QuotaLimits->PagefileLimit =
+                        Process->QuotaBlock->QuotaEntry[2].Limit;
+                }
+            }
+            _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+            {
+                /* Get exception code */
+                Status = _SEH2_GetExceptionCode();
+            }
+            _SEH2_END;
 
             /* Dereference the process */
             ObDereferenceObject(Process);
@@ -303,6 +353,20 @@ NtQueryInformationProcess(IN HANDLE ProcessHandle,
         case ProcessLdtInformation:
         case ProcessWorkingSetWatch:
         case ProcessWx86Information:
+
+            /* Reference the process */
+            Status = ObReferenceObjectByHandle(ProcessHandle,
+                                               PROCESS_QUERY_INFORMATION,
+                                               PsProcessType,
+                                               PreviousMode,
+                                               (PVOID*)&Process,
+                                               NULL);
+            if (!NT_SUCCESS(Status)) break;
+
+            DPRINT1("Not implemented: %lx\n", ProcessInformationClass);
+
+            /* Dereference the process */
+            ObDereferenceObject(Process);
             Status = STATUS_NOT_IMPLEMENTED;
             break;
 
@@ -386,6 +450,29 @@ NtQueryInformationProcess(IN HANDLE ProcessHandle,
 
         /* WOW64: Not implemented */
         case ProcessWow64Information:
+
+            /* Set the return length */
+            Length = sizeof(ULONG_PTR);
+
+            if (ProcessInformationLength != Length)
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
+            /* Reference the process */
+            Status = ObReferenceObjectByHandle(ProcessHandle,
+                                               PROCESS_QUERY_INFORMATION,
+                                               PsProcessType,
+                                               PreviousMode,
+                                               (PVOID*)&Process,
+                                               NULL);
+            if (!NT_SUCCESS(Status)) break;
+
+            DPRINT1("Not implemented: ProcessWow64Information\n");
+
+            /* Dereference the process */
+            ObDereferenceObject(Process);
             Status = STATUS_NOT_IMPLEMENTED;
             break;
 
@@ -649,6 +736,42 @@ NtQueryInformationProcess(IN HANDLE ProcessHandle,
             ObDereferenceObject(Process);
             break;
 
+        case ProcessBreakOnTermination:
+
+            /* Set the return length*/
+            Length = sizeof(ULONG);
+            if (ProcessInformationLength != Length)
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
+            /* Reference the process */
+            Status = ObReferenceObjectByHandle(ProcessHandle,
+                                               PROCESS_QUERY_INFORMATION,
+                                               PsProcessType,
+                                               PreviousMode,
+                                               (PVOID*)&Process,
+                                               NULL);
+            if (!NT_SUCCESS(Status)) break;
+
+            /* Enter SEH for writing back data */
+            _SEH2_TRY
+            {
+                /* Return the BreakOnTermination state */
+                *(PULONG)ProcessInformation = Process->BreakOnTermination;
+            }
+            _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+            {
+                /* Get the exception code */
+                Status = _SEH2_GetExceptionCode();
+            }
+            _SEH2_END;
+
+            /* Dereference the process */
+            ObDereferenceObject(Process);
+            break;
+
         /* Per-process security cookie */
         case ProcessCookie:
 
@@ -677,6 +800,9 @@ NtQueryInformationProcess(IN HANDLE ProcessHandle,
                 Length = sizeof(ULONG);
             }
 
+            /* Indicate success */
+            Status = STATUS_SUCCESS;
+
             /* Enter SEH to protect write */
             _SEH2_TRY
             {
@@ -703,6 +829,7 @@ NtQueryInformationProcess(IN HANDLE ProcessHandle,
         case ProcessAffinityMask:
         case ProcessForegroundInformation:
         default:
+            DPRINT1("Unsupported or unimplemented: %lx\n", ProcessInformationClass);
             Status = STATUS_INVALID_INFO_CLASS;
     }
 
@@ -741,6 +868,7 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
     PROCESS_SESSION_INFORMATION SessionInfo = {0};
     PROCESS_PRIORITY_CLASS PriorityClass = {0};
     PVOID ExceptionPort;
+    ULONG Break;
     PAGED_CODE();
 
     /* Verify Information Class validity */
@@ -779,16 +907,16 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
     /* Check what kind of information class this is */
     switch (ProcessInformationClass)
     {
-        /* Quotas and priorities: not implemented */
-        case ProcessQuotaLimits:
-        case ProcessBasePriority:
-        case ProcessRaisePriority:
-            Status = STATUS_NOT_IMPLEMENTED;
-            break;
-
         /* Error/Exception Port */
         case ProcessExceptionPort:
 
+            /* Check buffer length */
+            if (ProcessInformationLength != sizeof(HANDLE))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Use SEH for capture */
             _SEH2_TRY
             {
@@ -799,9 +927,9 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
             {
                 /* Get the exception code */
                 Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* Get the LPC Port */
             Status = ObReferenceObjectByHandle(PortHandle,
@@ -826,6 +954,13 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
         /* Security Token */
         case ProcessAccessToken:
 
+            /* Check buffer length */
+            if (ProcessInformationLength != sizeof(PROCESS_ACCESS_TOKEN))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Use SEH for capture */
             _SEH2_TRY
             {
@@ -837,9 +972,9 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
             {
                 /* Get the exception code */
                 Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* Assign the actual token */
             Status = PspSetPrimaryToken(Process, TokenHandle, NULL);
@@ -848,6 +983,13 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
         /* Hard error processing */
         case ProcessDefaultHardErrorMode:
 
+            /* Check buffer length */
+            if (ProcessInformationLength != sizeof(ULONG))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Enter SEH for direct buffer read */
             _SEH2_TRY
             {
@@ -866,6 +1008,13 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
         /* Session ID */
         case ProcessSessionInformation:
 
+            /* Check buffer length */
+            if (ProcessInformationLength != sizeof(PROCESS_SESSION_INFORMATION))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Enter SEH for capture */
             _SEH2_TRY
             {
@@ -876,9 +1025,9 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
             {
                 /* Get the exception code */
                 Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* Setting the session id requires the SeTcbPrivilege */
             if (!SeSinglePrivilegeCheck(SeTcbPrivilege, PreviousMode))
@@ -942,11 +1091,11 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
             }
             _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
             {
-                /* Get the exception code */
+                /* Return the exception code */
                 Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* Check for invalid PriorityClass value */
             if (PriorityClass.PriorityClass > PROCESS_PRIORITY_CLASS_ABOVE_NORMAL)
@@ -974,6 +1123,113 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
             Status = STATUS_SUCCESS;
             break;
 
+        case ProcessQuotaLimits:
+
+            /* Check buffer length */
+            if (ProcessInformationLength != sizeof(QUOTA_LIMITS))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
+            DPRINT1("Not implemented: ProcessQuotaLimits\n");
+            Status = STATUS_NOT_IMPLEMENTED;
+            break;
+
+        case ProcessBasePriority:
+
+            /* Check buffer length */
+            if (ProcessInformationLength != sizeof(KPRIORITY))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
+            DPRINT1("Not implemented: ProcessBasePriority\n");
+            Status = STATUS_NOT_IMPLEMENTED;
+            break;
+
+        case ProcessRaisePriority:
+
+            /* Check buffer length */
+            if (ProcessInformationLength != sizeof(ULONG))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
+            DPRINT1("Not implemented: ProcessRaisePriority\n");
+            Status = STATUS_NOT_IMPLEMENTED;
+            break;
+
+        case ProcessWx86Information:
+
+            /* Check buffer length */
+            if (ProcessInformationLength != sizeof(HANDLE))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
+            DPRINT1("Not implemented: ProcessWx86Information\n");
+            Status = STATUS_NOT_IMPLEMENTED;
+            break;
+
+        case ProcessDebugPort:
+
+            /* Check buffer length */
+            if (ProcessInformationLength != sizeof(HANDLE))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
+            DPRINT1("Not implemented: ProcessDebugPort\n");
+            Status = STATUS_NOT_IMPLEMENTED;
+            break;
+
+        case ProcessBreakOnTermination:
+
+            /* Check buffer length */
+            if (ProcessInformationLength != sizeof(ULONG))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
+            /* Enter SEH for direct buffer read */
+            _SEH2_TRY
+            {
+                Break = *(PULONG)ProcessInformation;
+            }
+            _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+            {
+                /* Get exception code */
+                Break = 0;
+                Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
+            }
+            _SEH2_END;
+            
+            /* Setting 'break on termination' requires the SeDebugPrivilege */
+            if (!SeSinglePrivilegeCheck(SeDebugPrivilege, PreviousMode))
+            {
+                Status = STATUS_PRIVILEGE_NOT_HELD;
+                break;
+            }
+            
+            /* Set or clear the flag */
+            if (Break)
+            {
+                PspSetProcessFlag(Process, PSF_BREAK_ON_TERMINATION_BIT);
+            }
+            else
+            {
+                PspClearProcessFlag(Process, PSF_BREAK_ON_TERMINATION_BIT);
+            }
+
+            break;
+
         /* We currently don't implement any of these */
         case ProcessLdtInformation:
         case ProcessLdtSize:
@@ -982,6 +1238,7 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
         case ProcessUserModeIOPL:
         case ProcessEnableAlignmentFaultFixup:
         case ProcessAffinityMask:
+            DPRINT1("Not implemented: %lx\n", ProcessInformationClass);
             Status = STATUS_NOT_IMPLEMENTED;
             break;
 
@@ -990,11 +1247,10 @@ NtSetInformationProcess(IN HANDLE ProcessHandle,
         case ProcessIoCounters:
         case ProcessTimes:
         case ProcessPooledUsageAndLimits:
-        case ProcessWx86Information:
         case ProcessHandleCount:
         case ProcessWow64Information:
-        case ProcessDebugPort:
         default:
+            DPRINT1("Unsupported or unimplemented: %lx\n", ProcessInformationClass);
             Status = STATUS_INVALID_INFO_CLASS;
     }
 
@@ -1049,7 +1305,7 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
         Access = THREAD_SET_THREAD_TOKEN;
     }
 
-    /* Reference the process */
+    /* Reference the thread */
     Status = ObReferenceObjectByHandle(ThreadHandle,
                                        Access,
                                        PsThreadType,
@@ -1064,6 +1320,13 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
         /* Thread priority */
         case ThreadPriority:
 
+            /* Check buffer length */
+            if (ThreadInformationLength != sizeof(KPRIORITY))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Use SEH for capture */
             _SEH2_TRY
             {
@@ -1074,9 +1337,9 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
             {
                 /* Get the exception code */
                 Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* Validate it */
             if ((Priority > HIGH_PRIORITY) ||
@@ -1093,6 +1356,13 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
 
         case ThreadBasePriority:
 
+            /* Check buffer length */
+            if (ThreadInformationLength != sizeof(LONG))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Use SEH for capture */
             _SEH2_TRY
             {
@@ -1103,9 +1373,9 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
             {
                 /* Get the exception code */
                 Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* Validate it */
             if ((Priority > THREAD_BASE_PRIORITY_MAX) ||
@@ -1132,6 +1402,13 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
 
         case ThreadAffinityMask:
 
+            /* Check buffer length */
+            if (ThreadInformationLength != sizeof(ULONG_PTR))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Use SEH for capture */
             _SEH2_TRY
             {
@@ -1144,7 +1421,6 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
                 Status = _SEH2_GetExceptionCode();
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* Validate it */
             if (!Affinity)
@@ -1193,6 +1469,13 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
 
         case ThreadImpersonationToken:
 
+            /* Check buffer length */
+            if (ThreadInformationLength != sizeof(HANDLE))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Use SEH for capture */
             _SEH2_TRY
             {
@@ -1203,9 +1486,9 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
             {
                 /* Get the exception code */
                 Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* Assign the actual token */
             Status = PsAssignImpersonationToken(Thread, TokenHandle);
@@ -1213,6 +1496,13 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
 
         case ThreadQuerySetWin32StartAddress:
 
+            /* Check buffer length */
+            if (ThreadInformationLength != sizeof(ULONG_PTR))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Use SEH for capture */
             _SEH2_TRY
             {
@@ -1223,9 +1513,9 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
             {
                 /* Get the exception code */
                 Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* Set the address */
             Thread->Win32StartAddress = Address;
@@ -1233,6 +1523,13 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
 
         case ThreadIdealProcessor:
 
+            /* Check buffer length */
+            if (ThreadInformationLength != sizeof(ULONG_PTR))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Use SEH for capture */
             _SEH2_TRY
             {
@@ -1243,9 +1540,9 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
             {
                 /* Get the exception code */
                 Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* Validate it */
             if (IdealProcessor > MAXIMUM_PROCESSORS)
@@ -1274,6 +1571,13 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
 
         case ThreadPriorityBoost:
 
+            /* Check buffer length */
+            if (ThreadInformationLength != sizeof(ULONG_PTR))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Use SEH for capture */
             _SEH2_TRY
             {
@@ -1284,9 +1588,9 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
             {
                 /* Get the exception code */
                 Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* Call the kernel */
             KeSetDisableBoostThread(&Thread->Tcb, (BOOLEAN)DisableBoost);
@@ -1294,6 +1598,13 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
 
         case ThreadZeroTlsCell:
 
+            /* Check buffer length */
+            if (ThreadInformationLength != sizeof(ULONG_PTR))
+            {
+                Status = STATUS_INFO_LENGTH_MISMATCH;
+                break;
+            }
+
             /* Use SEH for capture */
             _SEH2_TRY
             {
@@ -1304,9 +1615,9 @@ NtSetInformationThread(IN HANDLE ThreadHandle,
             {
                 /* Get the exception code */
                 Status = _SEH2_GetExceptionCode();
+                _SEH2_YIELD(break);
             }
             _SEH2_END;
-            if (!NT_SUCCESS(Status)) break;
 
             /* This is only valid for the current thread */
             if (Thread != PsGetCurrentThread())
@@ -1387,7 +1698,7 @@ NtQueryInformationThread(IN HANDLE ThreadHandle,
 {
     PETHREAD Thread;
     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
-    NTSTATUS Status = STATUS_SUCCESS;
+    NTSTATUS Status;
     ULONG Access;
     ULONG Length = 0;
     PTHREAD_BASIC_INFORMATION ThreadBasicInfo =
@@ -1396,26 +1707,26 @@ NtQueryInformationThread(IN HANDLE ThreadHandle,
     KIRQL OldIrql;
     PAGED_CODE();
 
+    /* Check if we were called from user mode */
     if (PreviousMode != KernelMode)
     {
+        /* Enter SEH */
         _SEH2_TRY
         {
+            /* Probe the buffer */
             ProbeForWrite(ThreadInformation,
                           ThreadInformationLength,
                           sizeof(ULONG));
 
-            if (ReturnLength)
-            {
-                ProbeForWriteUlong(ReturnLength);
-            }
+            /* Probe the return length if required */
+            if (ReturnLength) ProbeForWriteUlong(ReturnLength);
         }
         _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
         {
-            Status = _SEH2_GetExceptionCode();
+            /* Return the exception code */
+            _SEH2_YIELD(return _SEH2_GetExceptionCode());
         }
         _SEH2_END;
-
-        if (!NT_SUCCESS(Status)) return Status;
     }
 
     /* Check what class this is */
@@ -1599,9 +1910,19 @@ NtQueryInformationThread(IN HANDLE ThreadHandle,
             KeLowerIrql(OldIrql);
             break;
 
+        /* LDT and GDT information */
         case ThreadDescriptorTableEntry:
-            DPRINT1("NtQueryInformationThread(): case ThreadDescriptorTableEntry not implemented!\n");
+
+#if defined(_X86_)
+            /* Call the worker routine */
+            Status = PspQueryDescriptorThread(Thread,
+                                              ThreadInformation,
+                                              ThreadInformationLength,
+                                              ReturnLength);
+#else
+            /* Only implemented on x86 */
             Status = STATUS_NOT_IMPLEMENTED;
+#endif
             break;
 
         case ThreadPriorityBoost: