Re: [PATCH v2] sysvinit-inittab: support non-busybox-getty on serial consoles

[Andreas Oberritter <obi@opendreambox.org>]

Hi André,

On Fri,  8 Feb 2019 16:48:32 +0000
André Draszik <git@andred.net> wrote:

> From: André Draszik <andre.draszik@jci.com>
> 
> Busybox' getty has code to try to make itself a session leader,
> whereas util-linux' agetty doesn't. It expects this to happen
> from outside.
> When getty is not a session leader, many things don't work on
> the serial console, e.g. setting the terminal process group,
> job control doesn't work, etc.
> 
> Executing image tests also fails with AssertionErrors, because
>     Feb  5 16:12:55 qemuarm getty[590]: /dev/ttyAMA1: cannot get controlling tty: Operation not permitted
>     Feb  5 16:12:55 qemuarm getty[590]: /dev/ttyAMA1: cannot set process group: Inappropriate ioctl for device
> 
> Update the start_getty script to invoke getty via the setsid
> utility if needed, i.e. if /sbin/getty is not busybox getty.
> 
> [YOCTO #13058]
> 
> Signed-off-by: André Draszik <andre.draszik@jci.com>
> 
> ---
> v2: fork fewer processes
> ---
>  .../sysvinit/sysvinit-inittab/start_getty          | 14 +++++++++++++-
>  .../sysvinit/sysvinit-inittab_2.88dsf.bb           |  1 +
>  2 files changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/meta/recipes-core/sysvinit/sysvinit-inittab/start_getty b/meta/recipes-core/sysvinit/sysvinit-inittab/start_getty
> index e15ae35f90..d3ebb84e18 100644
> --- a/meta/recipes-core/sysvinit/sysvinit-inittab/start_getty
> +++ b/meta/recipes-core/sysvinit/sysvinit-inittab/start_getty
> @@ -13,6 +13,18 @@ active_serial=$(grep "serial" /proc/tty/drivers | cut -d/ -f1 | sed "s/ *$//")
>  # Rephrase input parameter from ttyS target index (ttyS1, ttyS2, ttyAMA0, etc).
>  runtime_tty=$(echo $2 | grep -oh '[0-9]')
>  
> +# busybox' getty does this itself, util-linux' agetty needs extra help
> +getty="/sbin/getty"
> +case $(readlink -f "${getty}") in
> +    */busybox*)
> +        ;;
> +    *)
> +        if [ -x "/usr/bin/setsid" ] ; then
> +            getty="/usr/bin/setsid ${getty}"
> +        fi
> +        ;;
> +esac
> +
>  # Backup $IFS.
>  DEFAULT_IFS=$IFS
>  # Customize Internal Field Separator.
> @@ -31,7 +43,7 @@ for line in $active_serial; do
>  			then
>  				if [ -c /dev/$2 ]
>  				then
> -				    /sbin/getty -L $1 $2 $3
> +				    eval ${getty} -L $1 $2 $3

I think using eval isn't necessary.

Best regards,
Andreas