Re: ANNOUNCE: 32-bit UID patch for Linux 2.0, 2.2

Jordan Mendelson (jordy@wserv.com)
Fri, 09 Jul 1999 00:00:25 -0400


Chris Wing wrote:
>
> The kernel patches maintain 100% backwards compatibility with
> everything except binary-only kernel modules :), by adding the minimum
> number of necessary new system calls to handle 32-bit UIDs and preserving
> all original system calls. A patched version of glibc 2.0 or 2.1 is
> necessary in order to use the new 32-bit system calls, but since glibc has
> always used 32-bit UIDs, you do not need to recompile any of your software
> (provided it was linked against glibc to begin with).

I reviewed your patch briefly and have a few comments.

The quota code doesn't appear to be updated. I know this will break backwards
compatibility and the quota code in general needs to be redone, but it should be
done or at least be put on the to do list.

The /proc filesystem needs to have a few things updated as well, things like
/proc/<pid>/status list the uid & gid of the owning process, otherwise ps is
going to break (though it will need updating anyway).

> I did this work on behalf of the University of Michigan, College of
> Engineering computer network (CAEN). U-M is (probably) one of the few
> organizations that needs 32-bit UID support, as we have over 130,000 users
> in a campus-wide shared Unix environment. (files and home directories are
> stored in AFS, /afs/*umich.edu)

But what if I need more than 4.2 billion users? *grin*.

Actually, what does UNIX98 say about UID length? Is it defined as 16, 32 or 64
bit?

Jordan

--
Jordan Mendelson     : http://jordy.wserv.com
Web Services, Inc.   : http://www.wserv.com

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