debug.c File Reference

#include <ntoskrnl.h>
#include <debug.h>

Include dependency graph for debug.c:

Go to the source code of this file.

Macros
#define	NDEBUG

Functions
NTSTATUS NTAPI	PsGetContextThread (IN PETHREAD Thread, IN OUT PCONTEXT ThreadContext, IN KPROCESSOR_MODE PreviousMode)
NTSTATUS NTAPI	PsSetContextThread (IN PETHREAD Thread, IN OUT PCONTEXT ThreadContext, IN KPROCESSOR_MODE PreviousMode)
NTSTATUS NTAPI	NtGetContextThread (IN HANDLE ThreadHandle, IN OUT PCONTEXT ThreadContext)
NTSTATUS NTAPI	NtSetContextThread (IN HANDLE ThreadHandle, IN PCONTEXT ThreadContext)

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 13 of file debug.c.

Function Documentation

NtGetContextThread()

NTSTATUS NTAPI NtGetContextThread	(	IN HANDLE	ThreadHandle,
		IN OUT PCONTEXT	ThreadContext
	)

Definition at line 350 of file debug.c.

{
    PETHREAD Thread;
    NTSTATUS Status;
    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
    PAGED_CODE();
 
    /* Get the Thread Object */
    Status = ObReferenceObjectByHandle(ThreadHandle,
                                       THREAD_GET_CONTEXT,
                                       PsThreadType,
                                       PreviousMode,
                                       (PVOID*)&Thread,
                                       NULL);
 
    if (!NT_SUCCESS(Status)) return Status;
 
    /* Make sure it's not a system thread */
    if (Thread->SystemThread)
    {
        /* Fail */
        Status = STATUS_INVALID_HANDLE;
    }
    else
    {
        /* Call the kernel API */
        Status = PsGetContextThread(Thread, ThreadContext, PreviousMode);
    }
 
    /* Dereference it and return */
    ObDereferenceObject(Thread);
    return Status;
}

Referenced by GetThreadContext().

NtSetContextThread()

NTSTATUS NTAPI NtSetContextThread	(	IN HANDLE	ThreadHandle,
		IN PCONTEXT	ThreadContext
	)

Definition at line 387 of file debug.c.

{
    PETHREAD Thread;
    NTSTATUS Status;
    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
    PAGED_CODE();
 
    /* Get the Thread Object */
    Status = ObReferenceObjectByHandle(ThreadHandle,
                                       THREAD_SET_CONTEXT,
                                       PsThreadType,
                                       PreviousMode,
                                       (PVOID*)&Thread,
                                       NULL);
 
    if (!NT_SUCCESS(Status)) return Status;
 
    /* Make sure it's not a system thread */
    if (Thread->SystemThread)
    {
        /* Fail */
        Status = STATUS_INVALID_HANDLE;
    }
    else
    {
        /* Call the kernel API */
        Status = PsSetContextThread(Thread, ThreadContext, PreviousMode);
    }
 
    /* Dereference it and return */
    ObDereferenceObject(Thread);
    return Status;
}

Referenced by SetThreadContext().

PsGetContextThread()

NTSTATUS NTAPI PsGetContextThread	(	IN PETHREAD	Thread,
		IN OUT PCONTEXT	ThreadContext,
		IN KPROCESSOR_MODE	PreviousMode
	)

Definition at line 119 of file debug.c.

{
    GET_SET_CTX_CONTEXT GetSetContext;
    ULONG Size = 0, Flags = 0;
    NTSTATUS Status;
 
    /* Enter SEH */
    _SEH2_TRY
    {
        /* Set default length */
        Size = sizeof(CONTEXT);
 
        /* Read the flags */
        Flags = ProbeForReadUlong(&ThreadContext->ContextFlags);
 
#ifdef _M_IX86
        /* Check if the caller wanted extended registers */
        if ((Flags & CONTEXT_EXTENDED_REGISTERS) !=
            CONTEXT_EXTENDED_REGISTERS)
        {
            /* Cut them out of the size */
            Size = FIELD_OFFSET(CONTEXT, ExtendedRegisters);
        }
#endif
 
        /* Check if we came from user mode */
        if (PreviousMode != KernelMode)
        {
            /* Probe the context */
            ProbeForWrite(ThreadContext, Size, sizeof(ULONG));
        }
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        /* Return the exception code */
        _SEH2_YIELD(return _SEH2_GetExceptionCode());
    }
    _SEH2_END;
 
    /* Initialize the wait event */
    KeInitializeEvent(&GetSetContext.Event, NotificationEvent, FALSE);
 
    /* Set the flags and previous mode */
    RtlZeroMemory(&GetSetContext.Context, Size);
    GetSetContext.Context.ContextFlags = Flags;
    GetSetContext.Mode = PreviousMode;
 
    /* Check if we're running in the same thread */
    if (Thread == PsGetCurrentThread())
    {
        /* Setup APC parameters manually */
        GetSetContext.Apc.SystemArgument1 = NULL;
        GetSetContext.Apc.SystemArgument2 = Thread;
 
        /* Enter a guarded region to simulate APC_LEVEL */
        KeEnterGuardedRegion();
 
        /* Manually call the APC */
        PspGetOrSetContextKernelRoutine(&GetSetContext.Apc,
                                        NULL,
                                        NULL,
                                        &GetSetContext.Apc.SystemArgument1,
                                        &GetSetContext.Apc.SystemArgument2);
 
        /* Leave the guarded region */
        KeLeaveGuardedRegion();
 
        /* We are done */
        Status = STATUS_SUCCESS;
    }
    else
    {
        /* Initialize the APC */
        KeInitializeApc(&GetSetContext.Apc,
                        &Thread->Tcb,
                        OriginalApcEnvironment,
                        PspGetOrSetContextKernelRoutine,
                        NULL,
                        NULL,
                        KernelMode,
                        NULL);
 
        /* Queue it as a Get APC */
        if (!KeInsertQueueApc(&GetSetContext.Apc, NULL, Thread, 2))
        {
            /* It was already queued, so fail */
            Status = STATUS_UNSUCCESSFUL;
        }
        else
        {
            /* Wait for the APC to complete */
            Status = KeWaitForSingleObject(&GetSetContext.Event,
                                           0,
                                           KernelMode,
                                           FALSE,
                                           NULL);
        }
    }
 
    _SEH2_TRY
    {
        /* Copy the context */
        RtlCopyMemory(ThreadContext, &GetSetContext.Context, Size);
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        /* Get the exception code */
        Status = _SEH2_GetExceptionCode();
    }
    _SEH2_END;
 
    /* Return status */
    return Status;
}

Referenced by NtGetContextThread().

PsSetContextThread()

NTSTATUS NTAPI PsSetContextThread	(	IN PETHREAD	Thread,
		IN OUT PCONTEXT	ThreadContext,
		IN KPROCESSOR_MODE	PreviousMode
	)

Definition at line 241 of file debug.c.

{
    GET_SET_CTX_CONTEXT GetSetContext;
    ULONG Size = 0, Flags = 0;
    NTSTATUS Status;
 
    /* Enter SEH */
    _SEH2_TRY
    {
        /* Set default length */
        Size = sizeof(CONTEXT);
 
        /* Read the flags */
        Flags = ProbeForReadUlong(&ThreadContext->ContextFlags);
 
#ifdef _M_IX86
        /* Check if the caller wanted extended registers */
        if ((Flags & CONTEXT_EXTENDED_REGISTERS) !=
            CONTEXT_EXTENDED_REGISTERS)
        {
            /* Cut them out of the size */
            Size = FIELD_OFFSET(CONTEXT, ExtendedRegisters);
        }
#endif
 
        /* Check if we came from user mode */
        if (PreviousMode != KernelMode)
        {
            /* Probe the context */
            ProbeForRead(ThreadContext, Size, sizeof(ULONG));
        }
 
        /* Copy the context */
        RtlCopyMemory(&GetSetContext.Context, ThreadContext, Size);
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        /* Return the exception code */
        _SEH2_YIELD(return _SEH2_GetExceptionCode());
    }
    _SEH2_END;
 
    /* Initialize the wait event */
    KeInitializeEvent(&GetSetContext.Event, NotificationEvent, FALSE);
 
    /* Set the flags and previous mode */
    GetSetContext.Context.ContextFlags = Flags;
    GetSetContext.Mode = PreviousMode;
 
    /* Check if we're running in the same thread */
    if (Thread == PsGetCurrentThread())
    {
        /* Setup APC parameters manually */
        GetSetContext.Apc.SystemArgument1 = UlongToPtr(1);
        GetSetContext.Apc.SystemArgument2 = Thread;
 
        /* Enter a guarded region to simulate APC_LEVEL */
        KeEnterGuardedRegion();
 
        /* Manually call the APC */
        PspGetOrSetContextKernelRoutine(&GetSetContext.Apc,
                                        NULL,
                                        NULL,
                                        &GetSetContext.Apc.SystemArgument1,
                                        &GetSetContext.Apc.SystemArgument2);
 
        /* Leave the guarded region */
        KeLeaveGuardedRegion();
 
        /* We are done */
        Status = STATUS_SUCCESS;
    }
    else
    {
        /* Initialize the APC */
        KeInitializeApc(&GetSetContext.Apc,
                        &Thread->Tcb,
                        OriginalApcEnvironment,
                        PspGetOrSetContextKernelRoutine,
                        NULL,
                        NULL,
                        KernelMode,
                        NULL);
 
        /* Queue it as a Get APC */
        if (!KeInsertQueueApc(&GetSetContext.Apc, UlongToPtr(1), Thread, 2))
        {
            /* It was already queued, so fail */
            Status = STATUS_UNSUCCESSFUL;
        }
        else
        {
            /* Wait for the APC to complete */
            Status = KeWaitForSingleObject(&GetSetContext.Event,
                                           0,
                                           KernelMode,
                                           FALSE,
                                           NULL);
        }
    }
 
    /* Return status */
    return Status;
}

Referenced by NtSetContextThread().