RtlULongPtrAdd - NtDoc

#ifndef _NTINTSAFE_H_INCLUDED_
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_SYSTEM | WINAPI_PARTITION_GAMES)
//
// ULONG_PTR addition
//
#ifdef _WIN64

#define RtlULongPtrAdd     RtlULongLongAdd

#endif
#endif
#endif
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#ifndef _NTINTSAFE_H_INCLUDED_
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_SYSTEM | WINAPI_PARTITION_GAMES)
//
// ULONG_PTR addition
//
#ifdef _WIN64
// ...
#else

_Must_inspect_result_
__inline
NTSTATUS
RtlULongPtrAdd(
    _In_ ULONG_PTR ulAugend,
    _In_ ULONG_PTR ulAddend,
    _Out_ _Deref_out_range_(==, ulAugend + ulAddend) ULONG_PTR* pulResult)
{
    NTSTATUS status;

    if ((ulAugend + ulAddend) >= ulAugend)
    {
        *pulResult = (ulAugend + ulAddend);
        status = STATUS_SUCCESS;
    }
    else
    {
        *pulResult = ULONG_PTR_ERROR;
        status = STATUS_INTEGER_OVERFLOW;
    }
    
    return status;
}

#endif
#endif
#endif
View code on GitHub