On Wed, Sep 10, 2008 at 11:54 PM, Carlos A. M. dos Santos <[EMAIL PROTECTED]> wrote: > On Wed, Sep 10, 2008 at 5:34 PM, Jeff Blank <[EMAIL PROTECTED]> 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.
I took some time to look at this again. I'm using 8.0-CURRENT now (GENERIC kernel), csup'ed and compiled yesterday. Xconsole is unable to open the console even if my user & group own /dev/console and the permissions are set to 0622. This happens because of the following code in xconsole.c: 289 int on = 1; 290 if (ioctl (tty_fd, TIOCCONS, (char *) &on) != -1) 291 input = fdopen (pty_fd, "r"); The ioctl call fails (EPERM) because only superuser can use TIOCCONS, regardless the ownership of the device. Using xterm with the "-C" argument works because xterm is installed with the setuid flag bit on. So the solution is "chmod +us xconsole". -- cd /usr/ports/sysutils/life make clean _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
