85 lines
1.4 KiB
C
85 lines
1.4 KiB
C
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/*++
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Copyright (c) 1989 Microsoft Corporation
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Module Name:
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deviosup.c
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Abstract:
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This module implements the memory locking routines for MSFS.
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Author:
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Manny Weiser (mannyw) 05-Apr-1991
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Revision History:
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--*/
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#include "mailslot.h"
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//
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// Local debug trace level
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//
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#define Dbg (DEBUG_TRACE_DEVIOSUP)
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#ifdef ALLOC_PRAGMA
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#pragma alloc_text( PAGE, MsMapUserBuffer )
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#endif
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VOID
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MsMapUserBuffer (
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IN OUT PIRP Irp,
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IN KPROCESSOR_MODE AccessMode,
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OUT PVOID *UserBuffer
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)
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/*++
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Routine Description:
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This routine obtains a usable virtual address for the user buffer
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for the current I/O request in the specified mode.
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Arguments:
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Irp - Pointer to the Irp for the request.
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AccessMode - UserMode or KernelMode.
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UserBuffer - Returns pointer to mapped user buffer.
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Return Value:
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None.
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--*/
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{
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AccessMode;
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PAGED_CODE();
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//
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// If there is no Mdl, then we must be in the Fsd, and we can simply
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// return the UserBuffer field from the Irp.
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//
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if (Irp->MdlAddress == NULL) {
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*UserBuffer = Irp->UserBuffer;
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return;
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}
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//
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// Get a system virtual address for the buffer.
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//
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*UserBuffer = MmGetSystemAddressForMdl( Irp->MdlAddress );
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return;
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} // MsMapUserBuffer
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