ulimit -- You don't need sources!

[Paul S. Sawyer]

In article <697 at occrsh.ATT.COM>, rjd at occrsh.ATT.COM (Randy_Davis) writes:
>   Wrong - all of these schemes to change the ulimit BEFORE the login program
> is run from the normal sequence init-getty-login-shell will not work!!!

But - - my scheme to raise the ulimit before getty (as I recently posted)
DOES work, and HAS been working all along! (or I would not be using it!   B-)  
This is System V.2.1.1; it also worked on 2.0.? (3B5).


>   If the ulimit is set to some high number before login is run (and, in fact it
> IS), such as in the kernel, and if you are running a System V version before the
> ulimit was settable in the /etc/master.d/kernel file, the ulimit for logins is
> last set in the /bin/login program.  So, setting your kernel, your init, or
> your getty ulimit higher would be fine, yet as soon as a person logs in and
> run this (pre-3.0) /bin/login, the line "ulimit(2,<low number>);" (near line
> 248 in the source if you are curious) would be implemented for all non-root
> logins, and you are back to where you started.

I AM curious.  But AT&T has not seen fit to include the source for
/bin/login to binary licensees just because they are curious.  Since login
runs suid root, and is called by init running as root, does it really do
that based on login name, or user id?  I suspect the latter... hmmm, I
just did a "exec login paul" and kept my 100,000 block ulimit, so it isn't
real user id...  or, what is <low number>? if I don't set it up, it seems to
be 2048... or my system is broke, but PLEASE DON'T FIX IT!!

>   To solve the problem on pre-3.0 release AT&T System V Unix operating systems
> for user logins, you must change the login program.  On 3.0 and later releases,

If I must, I must.  This seems to imply that AT&T must start supplying source
code for /bin/login and several other files important to a customer's use
of the system.  This falls far short of our needing to become source
licensees.  The initial discussion, I believe, was how to get around the
ulimit (which some consider good, some consider evil) if you don't have
source.  (Anything is possible if the Source is with you...  B-)

> it is a tunable parameter in the /etc/master.d/kernel file.  To change it for
> non-user process (cron, etc..), a change in the /etc/rc script might be
> sufficient.

This is a good idea - - would it cure the "at" problem?


> Randy Davis					UUCP: ...(att!)ocrjd!randy
> 						      ...(att!)occrsh!rjd


-- 
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Paul S. Sawyer              uunet!unh!unhtel!paul     paul at unhtel.UUCP
UNH Telecommunications
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