RtlULongPtrToULong - NtDoc

Native API online documentation, based on the System Informer (formerly Process Hacker) phnt headers
#ifndef _NTINTSAFE_H_INCLUDED_
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_SYSTEM | WINAPI_PARTITION_GAMES)
//
// ULONG_PTR -> ULONG conversion
//
#ifdef _WIN64

#define RtlULongPtrToULong RtlULongLongToULong

#endif
#endif
#endif

View code on GitHub
#ifndef _NTINTSAFE_H_INCLUDED_
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_SYSTEM | WINAPI_PARTITION_GAMES)
//
// ULONG_PTR -> ULONG conversion
//
#ifdef _WIN64
// ...
#else

_Must_inspect_result_
__inline
NTSTATUS
RtlULongPtrToULong(
    _In_ ULONG_PTR ulOperand,
    _Out_ _Deref_out_range_(==, ulOperand) ULONG* pulResult)
{
    *pulResult = (ULONG)ulOperand;
    return STATUS_SUCCESS;
}

#endif
#endif
#endif

View code on GitHub
// ntintsafe.h

NTSTATUS RtlULongPtrToULong(
  [in]  ULONG_PTR ulOperand,
  [out] ULONG     *pulResult
);
View the official Windows Driver Kit DDI reference

NtDoc

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Windows Driver Kit DDI reference (nf-ntintsafe-rtlulongptrtoulong)

RtlULongPtrToULong function

Description

Converts a value of type ULONG_PTR to a value of type ULONG.

Parameters

ulOperand [in]

The value to be converted.

pulResult [out]

A pointer to the converted value. In the case where the conversion causes a truncation of the original value, the function returns STATUS_INTEGER_OVERFLOW and this parameter is not valid.

Return value

Returns STATUS_SUCCESS if the operation is successful.

See the implementation of this helper function in ntintsafe.h in the WDK for possible error return values.

Remarks

This is one of a set of inline functions designed to provide type conversions and perform validity checks with minimal impact on performance.