reactos/ntoskrnl/ke/except.c

   1 /*
   2  * PROJECT:         ReactOS Kernel
   3  * LICENSE:         GPL - See COPYING in the top level directory
   4  * FILE:            ntoskrnl/ke/except.c
   5  * PURPOSE:         Platform independent exception handling
   6  * PROGRAMMERS:     Alex Ionescu (alex.ionescu@reactos.org)
   7  */
   8
   9 /* INCLUDES ******************************************************************/
  10
  11 #include <ntoskrnl.h>
  12 #define NDEBUG
  13 #include <debug.h>
  14
  15 /* FUNCTIONS *****************************************************************/
  16
  17 VOID
  18 NTAPI
  19 KiContinuePreviousModeUser(IN PCONTEXT Context,
  20                            IN PKEXCEPTION_FRAME ExceptionFrame,
  21                            IN PKTRAP_FRAME TrapFrame)
  22 {
  23     CONTEXT LocalContext;
  24
  25     /* We'll have to make a copy and probe it */
  26     ProbeForRead(Context, sizeof(CONTEXT), sizeof(ULONG));
  27     RtlCopyMemory(&LocalContext, Context, sizeof(CONTEXT));
  28     Context = &LocalContext;
  29
  30     /* Convert the context into Exception/Trap Frames */
  31     KeContextToTrapFrame(&LocalContext,
  32                          ExceptionFrame,
  33                          TrapFrame,
  34                          LocalContext.ContextFlags,
  35                          UserMode);
  36 }
  37
  38 NTSTATUS
  39 NTAPI
  40 KiContinue(IN PCONTEXT Context,
  41            IN PKEXCEPTION_FRAME ExceptionFrame,
  42            IN PKTRAP_FRAME TrapFrame)
  43 {
  44     NTSTATUS Status = STATUS_SUCCESS;
  45     KIRQL OldIrql = APC_LEVEL;
  46     KPROCESSOR_MODE PreviousMode = KeGetPreviousMode();
  47
  48     /* Raise to APC_LEVEL, only if needed */
  49     if (KeGetCurrentIrql() < APC_LEVEL) KeRaiseIrql(APC_LEVEL, &OldIrql);
  50
  51     /* Set up SEH to validate the context */
  52     _SEH2_TRY
  53     {
  54         /* Check the previous mode */
  55         if (PreviousMode != KernelMode)
  56         {
  57             /* Validate from user-mode */
  58             KiContinuePreviousModeUser(Context,
  59                                        ExceptionFrame,
  60                                        TrapFrame);
  61         }
  62         else
  63         {
  64             /* Convert the context into Exception/Trap Frames */
  65             KeContextToTrapFrame(Context,
  66                                  ExceptionFrame,
  67                                  TrapFrame,
  68                                  Context->ContextFlags,
  69                                  KernelMode);
  70         }
  71     }
  72     _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
  73     {
  74         /* Save the exception code */
  75         Status = _SEH2_GetExceptionCode();
  76     }
  77     _SEH2_END;
  78
  79     /* Lower the IRQL if needed */
  80     if (OldIrql < APC_LEVEL) KeLowerIrql(OldIrql);
  81
  82     /* Return status */
  83     return Status;
  84 }
  85
  86 NTSTATUS
  87 NTAPI
  88 KiRaiseException(IN PEXCEPTION_RECORD ExceptionRecord,
  89                  IN PCONTEXT Context,
  90                  IN PKEXCEPTION_FRAME ExceptionFrame,
  91                  IN PKTRAP_FRAME TrapFrame,
  92                  IN BOOLEAN SearchFrames)
  93 {
  94     KPROCESSOR_MODE PreviousMode = KeGetPreviousMode();
  95     CONTEXT LocalContext;
  96     EXCEPTION_RECORD LocalExceptionRecord;
  97     ULONG ParameterCount, Size;
  98     NTSTATUS Status = STATUS_SUCCESS;
  99
 100     /* Check if we need to probe */
 101     if (PreviousMode != KernelMode)
 102     {
 103         /* Set up SEH */
 104         _SEH2_TRY
 105         {
 106             /* Probe the context */
 107             ProbeForRead(Context, sizeof(CONTEXT), sizeof(ULONG));
 108
 109             /* Probe the Exception Record */
 110             ProbeForRead(ExceptionRecord,
 111                          FIELD_OFFSET(EXCEPTION_RECORD, NumberParameters) +
 112                          sizeof(ULONG),
 113                          sizeof(ULONG));
 114
 115             /* Validate the maximum parameters */
 116             if ((ParameterCount = ExceptionRecord->NumberParameters) >
 117                 EXCEPTION_MAXIMUM_PARAMETERS)
 118             {
 119                 /* Too large */
 120                 Status = STATUS_INVALID_PARAMETER;
 121                 _SEH2_LEAVE;
 122             }
 123
 124             /* Probe the entire parameters now*/
 125             Size = (sizeof(EXCEPTION_RECORD) -
 126                     ((EXCEPTION_MAXIMUM_PARAMETERS - ParameterCount) * sizeof(ULONG)));
 127             ProbeForRead(ExceptionRecord, Size, sizeof(ULONG));
 128
 129             /* Now make copies in the stack */
 130             RtlCopyMemory(&LocalContext, Context, sizeof(CONTEXT));
 131             RtlCopyMemory(&LocalExceptionRecord, ExceptionRecord, Size);
 132             Context = &LocalContext;
 133             ExceptionRecord = &LocalExceptionRecord;
 134
 135             /* Update the parameter count */
 136             ExceptionRecord->NumberParameters = ParameterCount;
 137         }
 138         _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
 139         {
 140             DbgBreakPoint();
 141
 142             /* Return the exception code */
 143             _SEH2_YIELD(return _SEH2_GetExceptionCode());
 144         }
 145         _SEH2_END;
 146     }
 147
 148     /* Convert the context record */
 149     KeContextToTrapFrame(Context,
 150                          ExceptionFrame,
 151                          TrapFrame,
 152                          Context->ContextFlags,
 153                          PreviousMode);
 154
 155     /* Dispatch the exception */
 156     ExceptionRecord->ExceptionCode &= ~KI_EXCEPTION_INTERNAL;
 157     KiDispatchException(ExceptionRecord,
 158                         ExceptionFrame,
 159                         TrapFrame,
 160                         PreviousMode,
 161                         SearchFrames);
 162
 163     /* Return the status */
 164     return Status;
 165 }
 166
 167 /* EOF */