VOID
NTAPI
Ke386SetIOPL(VOID)
{
PKTHREAD Thread = KeGetCurrentThread();
PKPROCESS Process = Thread->ApcState.Process;
PKTRAP_FRAME TrapFrame;
CONTEXT Context;
/* IOPL was enabled for this process/thread */
Process->Iopl = TRUE;
Thread->Iopl = TRUE;
/* Get the trap frame on exit */
TrapFrame = KeGetTrapFrame(Thread);
/* Convert to a context */
Context.ContextFlags = CONTEXT_CONTROL;
KeTrapFrameToContext(TrapFrame, NULL, &Context);
/* Set the IOPL flag */
Context.EFlags |= EFLAGS_IOPL;
/* Convert back to a trap frame */
KeContextToTrapFrame(&Context, NULL, TrapFrame, CONTEXT_CONTROL, UserMode);
}
NTSTATUS
NTAPI
KiContinue(IN PCONTEXT Context,
IN PKEXCEPTION_FRAME ExceptionFrame,
IN PKTRAP_FRAME TrapFrame)
{
NTSTATUS Status = STATUS_SUCCESS;
KIRQL OldIrql = APC_LEVEL;
KPROCESSOR_MODE PreviousMode = KeGetPreviousMode();
/* Raise to APC_LEVEL, only if needed */
if (KeGetCurrentIrql() < APC_LEVEL) KeRaiseIrql(APC_LEVEL, &OldIrql);
/* Set up SEH to validate the context */
_SEH2_TRY
{
/* Check the previous mode */
if (PreviousMode != KernelMode)
{
/* Validate from user-mode */
KiContinuePreviousModeUser(Context,
ExceptionFrame,
TrapFrame);
}
else
{
/* Convert the context into Exception/Trap Frames */
KeContextToTrapFrame(Context,
ExceptionFrame,
TrapFrame,
Context->ContextFlags,
KernelMode);
}
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
/* Save the exception code */
Status = _SEH2_GetExceptionCode();
}
_SEH2_END;
/* Lower the IRQL if needed */
if (OldIrql < APC_LEVEL) KeLowerIrql(OldIrql);
/* Return status */
return Status;
}
VOID
NTAPI
KiContinuePreviousModeUser(IN PCONTEXT Context,
IN PKEXCEPTION_FRAME ExceptionFrame,
IN PKTRAP_FRAME TrapFrame)
{
CONTEXT LocalContext;
/* We'll have to make a copy and probe it */
ProbeForRead(Context, sizeof(CONTEXT), sizeof(ULONG));
RtlCopyMemory(&LocalContext, Context, sizeof(CONTEXT));
Context = &LocalContext;
/* Convert the context into Exception/Trap Frames */
KeContextToTrapFrame(&LocalContext,
ExceptionFrame,
TrapFrame,
LocalContext.ContextFlags,
UserMode);
}
/* FIXME: THIS IS TOTALLY BUSTED NOW */
VOID
NTAPI
KiInitializeContextThread(IN PKTHREAD Thread,
IN PKSYSTEM_ROUTINE SystemRoutine,
IN PKSTART_ROUTINE StartRoutine,
IN PVOID StartContext,
IN PCONTEXT ContextPointer)
{
PKTRAP_FRAME TrapFrame;
PKEXCEPTION_FRAME ExceptionFrame = NULL, CtxSwitchFrame;
//
// Check if this is a user thread
//
if (ContextPointer)
{
//
// Setup the initial frame
//
PKUINIT_FRAME InitFrame;
InitFrame = (PKUINIT_FRAME)((ULONG_PTR)Thread->InitialStack -
sizeof(KUINIT_FRAME));
//
// Setup the Trap Frame and Exception frame
//
TrapFrame = &InitFrame->TrapFrame;
ExceptionFrame = &InitFrame->ExceptionFrame;
///
// Zero out the trap frame and exception frame
//
RtlZeroMemory(TrapFrame, sizeof(KTRAP_FRAME));
RtlZeroMemory(ExceptionFrame, sizeof(KEXCEPTION_FRAME));
//
// Set up a trap frame from the context
//
KeContextToTrapFrame(ContextPointer,
ExceptionFrame,
TrapFrame,
ContextPointer->ContextFlags | CONTEXT_CONTROL,
UserMode);
//
// Set the previous mode as user
//
//TrapFrame->PreviousMode = UserMode;
Thread->PreviousMode = UserMode;
//
// Clear the return address
//
ExceptionFrame->Lr = 0;
//
// Context switch frame to setup below
//
CtxSwitchFrame = &InitFrame->CtxSwitchFrame;
}
else
{
//
// Set up the Initial Frame for the system thread
//
PKKINIT_FRAME InitFrame;
InitFrame = (PKKINIT_FRAME)((ULONG_PTR)Thread->InitialStack -
sizeof(KKINIT_FRAME));
//
// Set the previous mode as kernel
//
Thread->PreviousMode = KernelMode;
//
// Context switch frame to setup below
//
CtxSwitchFrame = &InitFrame->CtxSwitchFrame;
}
//
// Now setup the context switch frame
//
CtxSwitchFrame->Lr = (ULONG)KiThreadStartup;
CtxSwitchFrame->R11 = (ULONG)(ExceptionFrame ? ExceptionFrame : CtxSwitchFrame);
//
// Set the parameters
//
CtxSwitchFrame->R4 = (ULONG)ContextPointer;
CtxSwitchFrame->R5 = (ULONG)StartContext;
CtxSwitchFrame->R6 = (ULONG)StartRoutine;
CtxSwitchFrame->R7 = (ULONG)SystemRoutine;
//
// Save back the new value of the kernel stack
//
Thread->KernelStack = (PVOID)CtxSwitchFrame;
}
