[PATCH 0/3] linux: Allow console switching to work without root rights

[Peter Hutterer]

On Tue, Jan 21, 2014 at 09:47:31AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 01/21/2014 05:44 AM, Peter Hutterer wrote:
> >On Thu, Jan 16, 2014 at 11:24:48AM +0100, Hans de Goede wrote:
> >>This patch-set makes it possible to run without as non-root without
> >>-sharevts. With the caveat that the user must specify the vt from which X is
> >>started as the vt to run on (as both gdm and startx do by default).
> >
> >I think for startx that's a fedora patch, I don't think that's upstream.
> 
> So maybe we should upstream it ?
> 
> >>With this patch-set + my systemd-logind patches I can login as user on a vt,
> >>and do startx without needing a suid-root bit on my xserver.
> >>
> >>There are only 2 minor issues left with running as non root after this:
> >>1) One (harmless) error message about failing to get iopl rights
> >>2) Currently my /var/log is writable by the user as which I start x
> >>
> >>Solving 1) is something to do after I've figured out how we want to deal
> >>with UMS when the xserver is not suid root
> >>
> >>For 2), I'm thinking about just logging to the users home dir, so user hans
> >>would get a /home/hans/.Xorg.0.log file. Input on this is much appreciated.
> >
> >I'd be tempted to even skip logging to a file and log to stdout only. That
> >way whatever launches X can decide how to handle the log output,
> >specifically with a few minor changes in gdm we could make sure the output
> >ends up in the journal.
> 
> If we want to integrate nicely with the journal the easiest way would be to
> just use syslog. But some people are going to dislike xorg spamming their
> /var/log/messages

yeah, our log is a bit too verbose at the moment. syslog forces output to
the syslog, by printing to stdout we leave the policy of where it goes up to
the caller, i.e. the DM in the vast majority of the cases. and especially in
this particular case where we need some integration beyond "run Xorg on the
commandline" anyway.

> So maybe add syslog support + an option for selecting whether to use file
> based logging or syslog + a ./configure option to set the default (file
> or syslog) ?

I was thinking of a simple Xorg -nologfile to disable the log file. That
should be simple enough to add. I suspect we could get the same result right
now with -logfile /dev/null.

> And in the file case of /var/log/.... fails fall back to ~/.Xorg.#.log ?

how about $XDG_DATA_HOME/xorg/Xorg.#.log? That has a defined default as
well.

Cheers,
   Peter