linux-kernel - Re: Mounting /proc w/ kernel 3.4.0 - "uid" parameter no longer valid?

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Date:	Thu, 24 May 2012 12:52:08 -0700 (PDT)
From:	kd6lvw@...oo.com
To:	"Eric W. Biederman" <ebiederm@...ssion.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Mounting /proc w/ kernel 3.4.0 - "uid" parameter no longer valid?

--- On Thu, 5/24/12, Eric W. Biederman <ebiederm@...ssion.com> wrote:
> "D. Stussy" <spam+newsgroups@...-arc.ampr.org> writes:
> > proc:  unrecognized mount option "uid=1" or missing value
> >
> > This works under 3.3.6 and earlier (I never tried 3.3.7).  It appears that the
> > "uid" mount option was removed.  WHY?  More importantly, where is this change
> > listed?  I didn't see it in the git log.
> >
> > This is really bad as I rebooted a remotely colocated server and since the
> > procfs is not mounted, I cannot log in via SSH to correct the problem.
> >
> > OK, so there's not that much point in changing the UID of the procfs files, but
> > I preferred to set their default ownership to a non-privileged user. 
> 
> There has never been a uid= option to /proc in Linus's tree.  I believe
> if you look you will find this feature was from a patch (perhaps from
> your distro) that added that support.

I compile both the util-linux-ng and the kernel from source.  There is no distribution patch involved.  As noted, kernel version 3.3.6 didn't bitch about the setting, while 3.4.0 does and won't mount procfs.

>From the man page (copy at "http://linux.die.net/man/8/mount"):

"Mount options for proc

     "uid=value and gid=value 

"These options are recognized, but have no effect as far as I can see."

Removal of this compatibility should have been noted.  WHERE was it noted?  Linux.die.net is a distribution independent documentation site.  It might not do anything, but per mount's documentation, it is acceptable.

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