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MmProtectMdlSystemAddress routine

The MmProtectMdlSystemAddress routine sets the protection type for a memory address range.

Syntax


NTSTATUS MmProtectMdlSystemAddress(
  _In_  PMDLX MemoryDescriptorList,
  _In_  ULONG NewProtect
);

Parameters

MemoryDescriptorList [in]

Specifies the memory address range to set the protection type for.

NewProtect [in]

Specifies the new protection setting for the memory pages. Drivers should specify one of the following values:

PAGE_NOACCESS: The underlying memory pages cannot be read or written.
PAGE_READONLY: The underlying memory pages can only be read, not written.
PAGE_READWRITE: The underlying memory pages can be read or written.
PAGE_EXECUTE: The underlying memory pages can be executed, but not read or written.
PAGE_EXECUTE_READ: The underlying memory pages can be executed or read, but not written.
PAGE_EXECUTE_READWRITE: The underlying memory pages can be executed, read, or written.

Return value

MmProtectMdlSystemAddress returns an NTSTATUS code. The possible return values include:

Return code	Description
STATUS_SUCCESS	The routine successfully changed the protection type for the memory address range.
STATUS_INVALID_PAGE_PROTECTION	The value specified for NewProtect is not a valid one for this routine.
STATUS_NOT_MAPPED_VIEW	The MDL has not yet been mapped. MmProtectMdlSystemAddress can only be used on MDLs that have already been mapped.

Remarks

The MmProtectMdlSystemAddress routine can only be called on an MDL that has already been mapped. For example, the routine can be called on an MDL mapped by MmMapLockedPagesSpecifyCache.

Requirements