non owner likes to truncate table in oracle

 Without grant Drop any table, I used the following script

1. create a stored procedure

2. grant execute on that procedure to that user 

create or replace procedure userx.truncateTable( p_tname in varchar2 )

as

begin

execute immediate 'truncate table ' || p_tname;  --DDL, implicit commit

end;

 CREATE TABLE userx.TEMP11

   (x NUMBER(2,0),

    x2 VARCHAR2(20 CHAR),

    x3 VARCHAR2(20 CHAR),

    x4 VARCHAR2(20 CHAR),  

    x5 VARCHAR2(20 CHAR)  

    );

grant execute on   userx.truncateTable to usery;

have usery run 

execute  userx.truncateTable ('Temp11');