[BusyBox] ash (busybox) problem:"job control turned off" -- getty (tinylogin) problem: errno 25: Not a typewriter (printed as "Inappropriate ioctl for device")

[cajus.hahn at de.abb.com]

Hi,

I am using busybox 0.60.3 and tinylogin 1.02 on a x86 linux box with 2.4.18
kernel.

I use busybox ash as shell with job control turned on.
I call getty from inittab with:
ttyS1::askfirst:/sbin/getty -Lt10 ttyS1 115200 vt100

after entering the password the busybox built-in shell ash starts with
"sh: can´t access tty; job control turned off"

I found out, that this results from problem with getty:
in getty_main() is a part

#ifdef __linux__
      {
            int iv;

            iv = getpid();
            if (ioctl(0, TIOCSPGRP, &iv) < 0)
                  perror_msg("ioctl() TIOCSPGRP call failed");
      }
#endif

The ioctl fails with error 25 !
By the way, there is no error output on my system.
I suggest adding a sleep(2) after perror_msg()!
If you do this you will see the error message:
"getty: ioctl() TIOCSPGRP call failed: Inappropriate ioctl for device"

Tracking the reason for this error back to the tty_io.c in the kernel
sources:
The controlling tty is still the init process, not the getty process!
This leads to ENOTTY (Not a typewriter) which might mean "Not the
controlling TTY"!?

I found a solution in busybox init.c / run():

      /* Take over the controlling tty */
      ioctl(fd, TIOCSCTTY, 1);


I placed this in getty.c, it now looks like

    /* take over the controlling tty to avoid ENOTTY */
    /* (Taken from busybox init.c) */
    ioctl(1, TIOCSCTTY, 1);

#ifdef __linux__
      {
            int iv;

            iv = getpid();
            if (ioctl(0, TIOCSPGRP, &iv) < 0)
            {
                  perror_msg("ioctl() TIOCSPGRP call failed");
                  sleep(2);
          }
      }
#endif

I am not sure if the change should be placed inside the "#ifdef __linux__".

Cajus
(cajus.hahn at de.abb.com)