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!wdfkd.wdftagtracker

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The !wdfkd.wdftagtracker extension displays all available tag information (including tag value, line, file, and time) for a specified tag tracker.

!wdfkd.wdftagtracker TagObjectPointer [Flags]

Parameters

TagObjectPointer
A pointer to a tag tracker.

Flags
Optional. The kind of information to display. Flags can be any combination of the following bits. The default value is 0x0.

Bit 0 (0x1)
Displays the history of acquire operations and release operations on the object.

Bit 1 (0x2)
Displays the line number of the object in hexadecimal instead of decimal.

DLL

Wdfkd.dll

Frameworks

KMDF 1, UMDF 2

Additional Information

For more information, see Kernel-Mode Driver Framework Debugging.

Remarks

To retrieve a pointer to a tag tracker, use the !wdfkd.wdfobject extension on an internal framework object pointer.

To use tag tracking, you must enable both the Kernel-Mode Driver Framework (KMDF) verifier and handle tracking in the registry. Both of these settings are stored in the driver's Parameters\Wdf subkey of the HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services key.

To enable the KMDF verifier, set a nonzero value for VerifierOn.

To enable handle tracking, set the value of TrackHandles to the name of one or more object types, or specify an asterisk (*) to track all object types. For example, the following example specifies the tracking of references to all WDFDEVICE and WDFQUEUE objects.

TrackHandles: MULTI_SZ: WDFDEVICE WDFQUEUE

When you enable handle tracking for an object type, the framework tracks the references that are taken on any object of that type. This setting is useful in finding driver memory leaks that unreleased references cause. TrackHandles works only if the KMDF verifier is enabled.