114 lines
1.9 KiB
C
114 lines
1.9 KiB
C
/*++
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Copyright (c) 1991 Microsoft Corporation
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Module Name:
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vdmfault.c
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Abstract:
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This module contains the support for dispatching VDM page faults.
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Author:
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Sudeep Bharati (sudeepb) 30-Aug-1992
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Revision History:
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--*/
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#include "vdmp.h"
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BOOLEAN
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VdmDispatchPageFault(
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PKTRAP_FRAME TrapFrame,
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ULONG Mode,
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ULONG FaultAddr
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);
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#ifdef ALLOC_PRAGMA
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#pragma alloc_text(PAGE, VdmDispatchPageFault)
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#endif
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BOOLEAN
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VdmDispatchPageFault(
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PKTRAP_FRAME TrapFrame,
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ULONG Mode,
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ULONG FaultAddr
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)
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/*++
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Routine Description:
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This routine dispatches a v86 mode page fault to the VDM monitor.
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It verifies that the fault occurred below 1MB.
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Arguments:
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TrapFrame
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Mode - 0 - if read
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1 - if write
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FaultAddr - faulting address
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Return Value:
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True if successfull, False otherwise
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--*/
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{
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PVDM_TIB VdmTib;
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NTSTATUS Status = STATUS_SUCCESS;
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KIRQL OldIrql;
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PAGED_CODE();
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//
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// Raise Irql to APC level...
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//
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KeRaiseIrql(APC_LEVEL, &OldIrql);
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//
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// VdmTib is in user mode memory
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//
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try {
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//
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// Get a pointer to the VdmTib
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//
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VdmTib = NtCurrentTeb()->Vdm;
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if ((TrapFrame->EFlags & EFLAGS_V86_MASK) ||
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(TrapFrame->SegCs != (KGDT_R3_CODE | RPL_MASK))) {
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//
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// If the faulting address is above 1MB return failure
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//
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if (FaultAddr < 0x100000) {
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VdmTib->EventInfo.Event = VdmMemAccess;
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VdmTib->EventInfo.InstructionSize = 0;
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VdmTib->EventInfo.FaultInfo.FaultAddr = FaultAddr;
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VdmTib->EventInfo.FaultInfo.RWMode = Mode;
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VdmEndExecution(TrapFrame, VdmTib);
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}
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else {
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Status = STATUS_ILLEGAL_INSTRUCTION;
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}
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}
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} except(EXCEPTION_EXECUTE_HANDLER) {
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Status = GetExceptionCode();
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}
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KeLowerIrql(OldIrql);
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if (!NT_SUCCESS(Status)) {
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return FALSE;
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} else {
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return TRUE;
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}
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}
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