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vdmnpx.c File Reference

#include <ntos.h>
#include <vdmntos.h>
#include "vdmp.h"

Go to the source code of this file.

Functions

BOOLEAN VdmDispatchIRQ13 (PKTRAP_FRAME TrapFrame)
BOOLEAN VdmSkipNpxInstruction (PKTRAP_FRAME TrapFrame, ULONG Address32Bits, PUCHAR istream, ULONG InstructionSize)

Variables

UCHAR MOD16 [] = { 0, 1, 2, 0 }
UCHAR MOD32 [] = { 0, 1, 4, 0 }
UCHAR VdmUserCr0MapIn []
UCHAR VdmUserCr0MapOut []

Function Documentation

BOOLEAN VdmDispatchIRQ13 (  PKTRAP_FRAME  TrapFrame  ) 
 

Definition at line 54 of file vdmnpx.c.

References _VdmEventInfo::Event, _Vdm_Tib::EventInfo, EXCEPTION_EXECUTE_HANDLER, ExRaiseException(), FALSE, _VdmEventInfo::InstructionSize, L, NT_SUCCESS, NTSTATUS(), PAGED_CODE, Status, TRUE, VdmEndExecution(), VdmIrq13, VdmpGetVdmTib(), and VDMTIB_KPROBE. 

00059                     :
00060 
00061     This routine reflects an IRQ 13 event to the usermode monitor for this
00062     vdm.  The IRQ 13 must be reflected to usermode, so that it can properly
00063     be raised as an interrupt through the virtual PIC.
00064 
00065 Arguments:
00066 
00067     none
00068 
00069 Return Value:
00070 
00071     TRUE if the event was reflected
00072     FALSE if not
00073 
00074 --*/
00075 {
00076     EXCEPTION_RECORD ExceptionRecord;
00077     PVDM_TIB VdmTib;
00078     BOOLEAN Success;
00079     NTSTATUS Status;
00080 
00081     PAGED_CODE();
00082 
00083     Success = TRUE;
00084 
00085     Status = VdmpGetVdmTib(&VdmTib, VDMTIB_KPROBE);
00086     if (!NT_SUCCESS(Status)) {
00087        return(FALSE);
00088     }
00089 
00090     try {
00091         VdmTib->EventInfo.Event = VdmIrq13;
00092         VdmTib->EventInfo.InstructionSize = 0L;
00093     } except(EXCEPTION_EXECUTE_HANDLER) {
00094         ExceptionRecord.ExceptionCode = GetExceptionCode();
00095         ExceptionRecord.ExceptionFlags = 0;
00096         ExceptionRecord.NumberParameters = 0;
00097         ExRaiseException(&ExceptionRecord);
00098         Success = FALSE;
00099     }
00100 
00101     if (Success)  {             // insure that we do not redispatch an exception
00102         VdmEndExecution(TrapFrame,VdmTib);
00103         }
00104 
00105 
00106     return TRUE;
00107 }

BOOLEAN VdmSkipNpxInstruction (  PKTRAP_FRAME  TrapFrame,
ULONG  Address32Bits,
PUCHAR  istream,
ULONG  InstructionSize
) 
 

Definition at line 110 of file vdmnpx.c.

References ASSERT, DbgPrint, EXCEPTION_EXECUTE_HANDLER, FALSE, KeI386NpxPresent, MOD16, MOD32, and TRUE. 

00118                    :
00119 
00120     This functions gains control when the system has no installed
00121     NPX support, but the thread has cleared it's EM bit in CR0.
00122 
00123     The purpose of this function is to move the instruction
00124     pointer forward over the current NPX instruction.
00125 
00126 Enviroment:
00127 
00128     V86 MODE ONLY, first opcode byte already verified to be 0xD8 - 0xDF.
00129 
00130 Arguments:
00131 
00132 Return Value:
00133 
00134     TRUE if trap frame was modified to skip the NPX instruction
00135 
00136 --*/
00137 {
00138     UCHAR       ibyte, Mod, rm;
00139 
00140     ASSERT (!KeI386NpxPresent);
00141 
00142     //
00143     // This NPX instruction should be skipped
00144     //
00145 
00146     try {
00147         //
00148         // Get ModR/M byte for NPX opcode
00149         //
00150 
00151         istream += 1;
00152         ibyte = *istream;
00153         InstructionSize += 1;
00154 
00155         if (ibyte > 0xbf) {
00156             //
00157             // Outside of ModR/M range for addressing, all done
00158             //
00159 
00160             goto try_exit;
00161         }
00162 
00163         Mod = ibyte >> 6;
00164         rm  = ibyte & 0x7;
00165         if (Address32Bits) {
00166             InstructionSize += MOD32 [Mod];
00167             if (Mod == 0  &&  rm == 5) {
00168                 // disp 32
00169                 InstructionSize += 4;
00170             }
00171 
00172             //
00173             // If SIB byte, read it
00174             //
00175 
00176             if (rm == 4) {
00177                 istream += 1;
00178                 ibyte = *istream;
00179                 InstructionSize += 1;
00180 
00181                 if (Mod == 0  &&  (ibyte & 7) == 5) {
00182                     // disp 32
00183                     InstructionSize += 4;
00184                 }
00185             }
00186 
00187         } else {
00188             InstructionSize += MOD16 [Mod];
00189             if (Mod == 0  &&  rm == 6) {
00190                 // disp 16
00191                 InstructionSize += 2;
00192             }
00193         }
00194 
00195 try_exit:  ;
00196     } except (EXCEPTION_EXECUTE_HANDLER) {
00197 
00198         //
00199         // Some sort of fault !?
00200         //
00201 
00202 #if DBG
00203         DbgPrint ("P5_FPU_PATCH: V86: Fault occured\n");
00204 #endif
00205         return FALSE;
00206     }
00207 
00208     //
00209     // Adjust Eip to skip NPX instruction
00210     //
00211 
00212     TrapFrame->Eip += InstructionSize;
00213     TrapFrame->Eip &= 0xffff;
00214 
00215     return TRUE;
00216 }
}

Variable Documentation

UCHAR MOD16[] = { 0, 1, 2, 0 } [static]
 

Definition at line 32 of file vdmnpx.c.

Referenced by VdmSkipNpxInstruction().

UCHAR MOD32[] = { 0, 1, 4, 0 } [static]
 

Definition at line 33 of file vdmnpx.c.

Referenced by VdmSkipNpxInstruction().

UCHAR VdmUserCr0MapIn[]
 

Initial value:

 {
           0,
           CR0_PE,             
           CR0_EM,
           CR0_EM | CR0_MP
    }

Definition at line 34 of file vdmnpx.c.

Referenced by KeContextToKframes().

UCHAR VdmUserCr0MapOut[]
 

Initial value:

 {
       0,
       CR0_MP,
       CR0_MP,             
       CR0_MP,             
       CR0_EM,
       CR0_EM | CR0_MP,    
       CR0_EM | CR0_MP,
       CR0_EM | CR0_MP     
    }

Definition at line 41 of file vdmnpx.c.

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