Windows2000/private/ntos/ex/alpha/raisests.c

/*++
Copyright (c) 1990  Microsoft Corporation

Module Name:
    raisests.c

Abstract:
    This module implements routines to raise a general exception from kernel mode or a noncontinuable exception from kernel mode.

Author:
    David N. Cutler (davec) 18-Oct-1990

Environment:
    Any mode.

Revision History:
    Thomas Van Baak (tvb) 5-May-1992
        Adapted for Alpha AXP.
--*/

#include "exp.h"


// Define private function prototypes.
VOID ExpRaiseException (IN PEXCEPTION_RECORD ExceptionRecord);
VOID ExpRaiseStatus (IN NTSTATUS ExceptionCode);


VOID ExRaiseException (IN PEXCEPTION_RECORD ExceptionRecord)
/*++
Routine Description:
    This function raises a software exception by building a context record and calling the exception dispatcher directly.

    N.B. This routine is a shell routine that simply calls another routine
         to do the real work. The reason this is done is to avoid a problem
         in try/finally scopes where the last statement in the scope is a call to raise an exception.

Arguments:
    ExceptionRecord - Supplies a pointer to an exception record.
Return Value:
    None.
--*/
{
#ifdef DBGtvb
    DbgPrint("ExRaiseException(ExceptionRecord = %lx) Status = %lx\n", ExceptionRecord, ExceptionRecord->ExceptionCode);
);
#endif
    ExpRaiseException(ExceptionRecord);
    return;
}


VOID ExpRaiseException (IN PEXCEPTION_RECORD ExceptionRecord)
/*++
Routine Description:
    This function raises a software exception by building a context record and calling the exception dispatcher directly.
Arguments:
    ExceptionRecord - Supplies a pointer to an exception record.
Return Value:
    None.
--*/
{
    ULONG_PTR ControlPc;
    CONTEXT ContextRecord;
    FRAME_POINTERS EstablisherFrame;
    PRUNTIME_FUNCTION FunctionEntry;
    BOOLEAN InFunction;
    ULONG_PTR NextPc;
    NTSTATUS Status;

    // Capture the current context, virtually unwind to the caller of this
    // routine, set the fault instruction address to that of the caller, and
    // call the exception dispatcher.
    RtlCaptureContext(&ContextRecord);
    ControlPc = (ULONG_PTR)ContextRecord.IntRa - 4;
    FunctionEntry = RtlLookupFunctionEntry(ControlPc);
    NextPc = RtlVirtualUnwind(ControlPc, FunctionEntry, &ContextRecord, &InFunction, &EstablisherFrame, NULL);
    ContextRecord.Fir = (ULONGLONG)(LONG_PTR)NextPc + 4;
    ExceptionRecord->ExceptionAddress = (PVOID)ContextRecord.Fir;

    // If the exception is successfully dispatched, then continue execution.
    // Otherwise, give the kernel debugger a chance to handle the exception.
    if (RtlDispatchException(ExceptionRecord, &ContextRecord)) {
        Status = ZwContinue(&ContextRecord, FALSE);
    } else {
        Status = ZwRaiseException(ExceptionRecord, &ContextRecord, FALSE);
    }

    // Either the attempt to continue execution or the attempt to give
    // the kernel debugger a chance to handle the exception failed. Raise
    // a noncontinuable exception.
    ExRaiseStatus(Status);
}


VOID ExRaiseStatus (IN NTSTATUS ExceptionCode)
/*++
Routine Description:
    This function raises an exception with the specified status value by building an exception record, building a context record, and calling the
    exception dispatcher directly. The exception is marked as noncontinuable with no parameters. There is no return from this function.

    N.B. This routine is a shell routine that simply calls another routine
         to do the real work. The reason this is done is to avoid a problem
         in try/finally scopes where the last statement in the scope is a call to raise an exception.

Arguments:
    ExceptionCode - Supplies the status value to be used as the exception code for the exception that is to be raised.
--*/
{
#ifdef DBGxx
    DbgPrint("ExRaiseStatus(ExceptionCode = %lx)\n", ExceptionCode);
#endif
    ExpRaiseStatus(ExceptionCode);
}


VOID ExpRaiseStatus (IN NTSTATUS ExceptionCode)
/*++
Routine Description:
    This function raises an exception with the specified status value by building an exception record, building a context record, and calling the
    exception dispatcher directly. The exception is marked as noncontinuable with no parameters. There is no return from this function.
Arguments:
    ExceptionCode - Supplies the status value to be used as the exception code for the exception that is to be raised.
--*/
{
    ULONG_PTR ControlPc;
    CONTEXT ContextRecord;
    FRAME_POINTERS EstablisherFrame;
    EXCEPTION_RECORD ExceptionRecord;
    PRUNTIME_FUNCTION FunctionEntry;
    BOOLEAN InFunction;
    ULONG_PTR NextPc;
    NTSTATUS Status;

    // Construct an exception record.
    ExceptionRecord.ExceptionCode = ExceptionCode;
    ExceptionRecord.ExceptionRecord = (PEXCEPTION_RECORD)NULL;
    ExceptionRecord.NumberParameters = 0;
    ExceptionRecord.ExceptionFlags = EXCEPTION_NONCONTINUABLE;

    // Capture the current context, virtually unwind to the caller of this
    // routine, set the fault instruction address to that of the caller, and
    // call the exception dispatcher.
    RtlCaptureContext(&ContextRecord);
    ControlPc = (ULONG_PTR)ContextRecord.IntRa - 4;
    FunctionEntry = RtlLookupFunctionEntry(ControlPc);
    NextPc = RtlVirtualUnwind(ControlPc, FunctionEntry, &ContextRecord, &InFunction, &EstablisherFrame, NULL);
    ContextRecord.Fir = (ULONGLONG)(LONG_PTR)NextPc + 4;
    ExceptionRecord.ExceptionAddress = (PVOID)ContextRecord.Fir;
    RtlDispatchException(&ExceptionRecord, &ContextRecord);

    // An unwind was not initiated during the dispatching of a noncontinuable
    // exception. Give the kernel debugger a chance to handle the exception.
    Status = ZwRaiseException(&ExceptionRecord, &ContextRecord, FALSE);

    // The attempt to give the kernel debugger a chance to handle the exception
    // failed. Raise another noncontinuable exception.
    ExRaiseStatus(Status);
}