find out which user has this OS pid...

All, how can I find out which user has this OS PID in oracle and where is he loggind in from.
oracle 2858 1 0 Nov 28 ? 0:00 oracleprod (LOCAL=NO)
this proc has been running to long.

select S.* from gv$session S, gv$process P
where spid=2858
and S.paddr=P.addr
;

execute this sql, IN spid give your OS pid number

select a.serial#,a.osuser,a.program,a.machine,c.sql_text from v$session a, v$process b,v$sqlarea c
where a.paddr=b.addr
and b.spid=&spid
and a.sql_hash_value=c.hash_value
/