PROC_THREAD_ATTRIBUTE - NtDoc

#ifndef _NTPSAPI_H
// User processes and threads
#if (PHNT_MODE != PHNT_MODE_KERNEL)

// private
typedef struct _PROC_THREAD_ATTRIBUTE
{
    ULONG_PTR Attribute;
    SIZE_T Size;
    ULONG_PTR Value;
} PROC_THREAD_ATTRIBUTE, *PPROC_THREAD_ATTRIBUTE;

#endif
#endif
View code on GitHub