RTL_QUERY_REGISTRY_ROUTINE - NtDoc

Native API online documentation, based on the System Informer (formerly Process Hacker) phnt headers
#ifndef _NTRTL_H

_Function_class_(RTL_QUERY_REGISTRY_ROUTINE)
typedef NTSTATUS (NTAPI RTL_QUERY_REGISTRY_ROUTINE)(
    _In_ PCWSTR ValueName,
    _In_ ULONG ValueType,
    _In_ PVOID ValueData,
    _In_ ULONG ValueLength,
    _In_opt_ PVOID Context,
    _In_opt_ PVOID EntryContext
    );

#endif

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This callback function is documented in Windows Driver Kit.