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MmGetMdlByteCount macro (wdm.h)

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The MmGetMdlByteCount macro returns the length, in bytes, of the buffer described by the specified MDL.

Syntax

ULONG MmGetMdlByteCount(
  [in] PMDL Mdl
);

Parameters

Mdl

A pointer to an MDL structure that describes the layout of a virtual memory buffer in physical memory. For more information, see Using MDLs.

Return value

MmGetMdlByteCount returns the length, in bytes, of the buffer described by Mdl.

Remarks

Macro definition:

#define MmGetMdlByteCount(Mdl)  ((Mdl)->ByteCount)

Callers of MmGetMdlByteCount can be running at any IRQL. Usually, callers are running at IRQL <= DISPATCH_LEVEL.

Requirements

Requirement Value
Target Platform Desktop
Header wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
IRQL Any level (see Remarks section)
DDI compliance rules MdlAfterReqCompletedIntIoctlA(kmdf), MdlAfterReqCompletedIoctlA(kmdf), MdlAfterReqCompletedReadA(kmdf), MdlAfterReqCompletedWriteA(kmdf)

See also

MDL

MmGetMdlByteOffset