From: D.Bolla (db1@ukc.ac.uk)
Date: 02/11/92


From: db1@ukc.ac.uk (D.Bolla)
Subject: CTRL-ALT-DEL + Make question
Date: 11 Feb 1992 09:23:49 GMT


Hello.

Few more questions about Linux :-)

1) As I see it now a "non root user" cannot use chown to change owner of
   a file. I understand that it is posix.... but I would like to point out
   that:
   I see linux as a "friendly" operating system that allows you to do as
   much as possible without many restrictions.
   I would like linux to be as fast as possible. And I am thinking about
   NOT putting into the kernel stuff like :
   Check for user disk quota
   Check for user cpu, system, time exceeded and so on.
   Trace of any user syscall or stuff like that.

2) Looking around in the kernel I see that there is a "function" reboot in
   keyboard.S that is used to reboot the machine.
   This is called directly from inside keyboard.S and has no check for
   processes active or anything.
   I was thinking:
   Will it be possible to make the reboot "function" to call a special
   version of kill Eg. killall that try to kill all processes of the system
   APART init and if the user press CTRl-ALT-DEL three times it finally
   does the reboot of the machine.
   something like:

   static int attempt=0;
   safe_reboot
      {
      switch ( attempt )
         {
         case 0:
            killall (SIGTERM); /* Try to kill in a nice way */
            attempt++;
            break;
         case 1:
            killall (SIGKILL); /* Use brute force now */
            attempt++;
            break;
         default:
            reboot(); /* Just reset the machine */
            break;
         }
      }

    Is this possible ?

3) I tryed to use make as a "non root" user and make complains about the
   fact that it can't do setuid().... I am posting this by memory now so I
   can't remembar the exact version of make ( if there is any ).
   I just would like to know if any other user has experienced problems in
   running make as non root and where I can find a public domain version of
   make ( Source code ).

Damiano