freebsd stable - Sep 2008 - can't see non-root writes to /dev/console

I just upgraded a RELENG_7 (amd64) box from 20080714 to "latest"
(which seems to be from a few days ago--no changes from Monday
morning's csup to today's) and can no longer see the effect of writing
to /dev/console as non-root.  When I log in using xdm, my user owns
/dev/console, mode 0622 (-rw--w--w-), and I start an 'xterm -C'.  But
when I, for example,

echo foo > /dev/console

I see nothing in the console xterm.  No error messages, and echo exits
0.  If I su to root and do the same, I get 'foo' in the same console
xterm.  Syslog messages to /dev/console also appear, of course.  All
the above applies to xconsole as well, not just xterm.  I did
recompile xterm from 20080616 ports, but it didn't fix the issue
(didn't expect it to, as xterm clearly has no trouble attaching and
reading).  So my echo is getting lost in the kernel, I guess.

Known problem?  Intentional change?  Something else?

thanks,
Jeff

On Wed, Sep 10, 2008 at 04:34:51PM -0400, Jeff Blank
wrote:
> I just upgraded a RELENG_7 (amd64) box from 20080714 to "latest"
> (which seems to be from a few days ago--no changes from Monday
> morning's csup to today's) and can no longer see the effect of
writing
> to /dev/console as non-root.
Sorry, I should have mentioned that my kernel is GENERIC + 'options
DEVICE_POLLING'.  And I guess I havn't updated my kernel config file
since the last time amd64/GENERIC changed, but the only (other)
differences are that I don't have device lines for igb, age, et, or
jme.

Jeff

On Wed, Sep 10, 2008 at 5:34 PM, Jeff Blank <jb000002@mr-happy.com>
wrote:
> I just upgraded a RELENG_7 (amd64) box from 20080714 to "latest"
> (which seems to be from a few days ago--no changes from Monday
> morning's csup to today's) and can no longer see the effect of
writing
> to /dev/console as non-root.  When I log in using xdm, my user owns
> /dev/console, mode 0622 (-rw--w--w-), and I start an 'xterm -C'. 
But
> when I, for example,
>
> echo foo > /dev/console
>
> I see nothing in the console xterm.  No error messages, and echo exits
> 0.  If I su to root and do the same, I get 'foo' in the same
console
> xterm.  Syslog messages to /dev/console also appear, of course.  All
> the above applies to xconsole as well, not just xterm.  I did
> recompile xterm from 20080616 ports, but it didn't fix the issue
> (didn't expect it to, as xterm clearly has no trouble attaching and
> reading).  So my echo is getting lost in the kernel, I guess.
>
> Known problem?  Intentional change?  Something else?
I have seen this problem since 6.x times and still on 7.x. I also
noticed that if I send something to the console after xconsole starts
then I can sned messages as an ordinary user. My workaround was
modifying the Xsetup_0 script (I used xdm for login), adding a line
with

     (sleep 3; date >> "$dev_console") &

just after starting xconsole.

I didn't have time to set up a machine with 8-CURRENT yet, so I could
not check if the new mp-safe tty implementation fixes this, either
intentionally or by a fortunate side effect.

-- 
cd /usr/ports/sysutils/life
make clean