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//+-----------------------------------------------------------------------
//
// Microsoft Windows
//
// Copyright (c) Microsoft Corporation 1992 - 1994
//
// File: context.cxx
//
// Contents: context kernel-mode functions
//
//
// History: 3/17/94 MikeSw Created
//
//------------------------------------------------------------------------
#include <sspdrv.h>
//+-------------------------------------------------------------------------
//
// Function: DeleteKernelContext
//
// Synopsis: Deletes a kernel context
//
// Effects: Frees memory, closes token handle.
//
// Arguments:
//
// Requires:
//
// Returns:
//
// Notes:
//
//--------------------------------------------------------------------------
SECURITY_STATUS
DeleteKernelContext(PKernelContext * ppList,
PKSPIN_LOCK pslLock,
PKernelContext pContext)
{
KIRQL OldIrql;
//
// First, find the record, then unlink the record from the list,
// and fix up pointers.
//
KeAcquireSpinLock(pslLock, &OldIrql);
if (!pContext)
{
KeReleaseSpinLock(pslLock, OldIrql);
return(SEC_E_INVALID_HANDLE);
}
//
// Now unlink from the list
//
if (pContext->pPrev)
{
pContext->pPrev->pNext = pContext->pNext;
}
else
{
*ppList = pContext->pNext;
}
if (pContext->pNext)
{
pContext->pNext->pPrev = pContext->pPrev;
}
//
// copy out the package-specific context to return.
// We are done with the list so we can release the spin lock
//
KeReleaseSpinLock(pslLock, OldIrql);
if (pContext->TokenHandle != NULL)
{
NtClose(pContext->TokenHandle);
}
if (pContext->AccessToken != NULL)
{
ObDereferenceObject(pContext->AccessToken);
}
// And, finally, return the context record to our pool:
FreeContextRec(pContext);
return(STATUS_SUCCESS);
}
//+-------------------------------------------------------------------------
//
// Function: AddKernelContext
//
// Synopsis:
//
// Effects:
//
// Arguments:
//
// Requires:
//
// Returns:
//
// Notes:
//
//--------------------------------------------------------------------------
void
AddKernelContext( PKernelContext * ppList,
PKSPIN_LOCK pslLock,
PKernelContext pContext)
{
KIRQL OldIrql;
KeAcquireSpinLock(pslLock, &OldIrql);
pContext->pNext = *ppList;
if (pContext->pNext)
{
pContext->pNext->pPrev = pContext;
}
pContext->pPrev = NULL;
*ppList = pContext;
KeReleaseSpinLock(pslLock, OldIrql);
}
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