[CRIU] [PATCH] tty: Make sure the controlling terminal is restored by session leader

[Andrew Vagin]

On Tue, Nov 20, 2012 at 06:09:17PM +0400, Cyrill Gorcunov wrote:
> The controling terminal should be sestored by a session leader,
> thus we need to test if the SID we've found in process tree
> is a leader.
> 
> Otherwise we might have pretty interesting situation: the user
> passed -j on dump, ie telling us to inherit shell jobs and on
> restore procedure the SID get inherited from the crtools but
> session leader for this sid doesn't belong to our peocess tree
> and thus we should not try to restore controlling terminal
> but inherit it as well.

Acked-by: Andrey Vagin <avagin at openvz.org>

> 
> Reported-by: Andrey Vagin <avagin at openvz.org>
> Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
> ---
>  tty.c |    7 ++++++-
>  1 files changed, 6 insertions(+), 1 deletions(-)
> 
> diff --git a/tty.c b/tty.c
> index ba8a6c1..1ecb0e5 100644
> --- a/tty.c
> +++ b/tty.c
> @@ -733,8 +733,13 @@ static int tty_find_restoring_task(struct tty_info *info)
>  				return 0;
>  		}
>  
> +		/*
> +		 * Find out the task which is session leader
> +		 * and it can restore the controlling terminal
> +		 * for us.
> +		 */
>  		item = find_first_sid(info->tie->sid);
> -		if (item) {
> +		if (item && item->pid.virt == item->sid) {
>  			pr_info("Set a control terminal %x to %d\n",
>  				info->tfe->id, info->tie->sid);
>  			return prepare_ctl_tty(item->pid.virt,
> -- 
> 1.7.7.6
>