PEPROCESS
PsGetCurrentProcess(
);
PsGetCurrentProcess returns a pointer to the process of the current thread.
Highest-level drivers, file systems in particular, can call this routine. Lower-level drivers should call IoGetCurrentProcess instead.
PsGetCurrentProcess is the most efficient way to get a pointer to the current process, no matter what environment is being used.
Callers of PsGetCurrentProcess must be running at IRQL PASSIVE_LEVEL.