2020-09-30 17:12:32 +02:00

76 lines
3.0 KiB
C

/*++
Copyright (c) 1990 Microsoft Corporation
Module Name:
apcuser.c
Abstract:
This module implements the machine dependent code necessary to initialize a user mode APC.
Author:
David N. Cutler (davec) 23-Apr-1990
Environment:
Kernel mode only, IRQL APC_LEVEL.
--*/
#include "ki.h"
VOID KiInitializeUserApc (
IN PKEXCEPTION_FRAME ExceptionFrame,
IN PKTRAP_FRAME TrapFrame,
IN PKNORMAL_ROUTINE NormalRoutine,
IN PVOID NormalContext,
IN PVOID SystemArgument1,
IN PVOID SystemArgument2
)
/*++
Routine Description:
This function is called to initialize the context for a user mode APC.
Arguments:
ExceptionFrame - Supplies a pointer to an exception frame.
TrapFrame - Supplies a pointer to a trap frame.
NormalRoutine - Supplies a pointer to the user mode APC routine.
NormalContext - Supplies a pointer to the user context for the APC routine.
SystemArgument1 - Supplies the first system supplied value.
SystemArgument2 - Supplies the second system supplied value.
--*/
{
CONTEXT ContextRecord;
EXCEPTION_RECORD ExceptionRecord;
LONG Length;
ULONG UserStack;
// Move the user mode state from the trap and exception frames to the context frame.
ContextRecord.ContextFlags = CONTEXT_FULL;
KeContextFromKframes(TrapFrame, ExceptionFrame, &ContextRecord);
// Transfer the context information to the user stack, initialize the APC routine parameters, and modify the trap frame so execution will
// continue in user mode at the user mode APC dispatch routine.
try {
// Compute length of context record and new aligned user stack pointer.
Length = sizeof(CONTEXT);
UserStack = (ULONG)(ContextRecord.XIntSp & (~7)) - Length;
// Probe user stack area for writeability and then transfer the context record to the user stack.
ProbeForWrite((PCHAR)UserStack, Length, sizeof(QUAD));
RtlMoveMemory((PULONG)UserStack, &ContextRecord, sizeof(CONTEXT));
// Set the address of the user APC routine, the APC parameters, the new frame pointer, and the new stack pointer in the current trap
// frame. Set the continuation address so control will be transfered to the user APC dispatcher.
TrapFrame->XIntSp = (LONG)UserStack;
TrapFrame->XIntS8 = (LONG)UserStack;
TrapFrame->XIntA0 = (LONG)NormalContext;
TrapFrame->XIntA1 = (LONG)SystemArgument1;
TrapFrame->XIntA2 = (LONG)SystemArgument2;
TrapFrame->XIntA3 = (LONG)NormalRoutine;
TrapFrame->Fir = KeUserApcDispatcher;
// If an exception occurs, then copy the exception information to an exception record and handle the exception.
} except (KiCopyInformation(&ExceptionRecord, (GetExceptionInformation())->ExceptionRecord)) {
// Set the address of the exception to the current program address and raise the exception by calling the exception dispatcher.
ExceptionRecord.ExceptionAddress = (PVOID)(TrapFrame->Fir);
KiDispatchException(&ExceptionRecord, ExceptionFrame, TrapFrame, UserMode, TRUE);
}
}