HP OpenVMS Systems

Unprivileged Supervisor-mode Logical Names?

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The Question is:

 
Wizard -
 
I'm using OpenVMS 7.2-1 (don't think that matters much however)...
 
The command:
 
$ DEFINE FOO BAR
 
creates a logical in my process name table at supervisor mode.
 
I just wrote a program that calls SYS$CRELNM. My program specified LNM$PROCESS
 for the logical name table, "FOO" for the logical, PSL$C_SUPER for the access
 mode, and the item list defined the equivalence string as "BAR." I ran my
 program many times and e
ach time the call to SYS$CRELNM returned SS$_NORMAL - yet when I issued a SHOW
 LOG/PROC after running the program I did not see my "FOO" logical. Then I
 noticed that if I issue a SET PROC/PRIV=SYSNAM before running my program my
 "FOO" logical shows up in
the process name table after I run my program.
 
To make a long story short after calming down a bit it did dawn on me that yes
 - the fine manual does say that the access mode argument is maximized with the
 access mode of the caller (and yes - I was executing in user mode).
 
Oh great wizard (yes I know the SET command is installed with privilege);
 however, if from DCL I can create a supervisor mode logical in my process name
 table (I logical which lest I am forgetting something can not affect anyone or
 anything on the system
other than me) why is it that SYS$CRELNM chooses to create my "FOO" logical at
 user mode in my process name table?
 

The Answer is :

 
  OpenVMS System Services will perform the requested task directly, and
  generally do not provide additional capabilities nor privileges, nor
  variable length argument lists, nor dynamic string descriptor support,
  etc.
 
  When the sys$crelnm system service is invoked in user-mode code, the
  system service can and will only define a user-mode logical name for
  a non-privileged user.
 
  It is possible to define a supervisor mode logical name from user-mode
  code using the RTL routine lib$set_logical.  This RTL routine is the
  callable equivalent of the DCL command DEFINE.
 
  If you wish to use the system service to define a supervisor-mode logical
  name, you must be in supervisor-mode or more privileged code, or you must
  possess additional privileges.
 

  

     

     
answer written or last revised on ( 12-MAR-2001 )
     
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