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Date:   Mon, 16 Jul 2018 16:55:40 +0200
From:   Oleg Nesterov <oleg@redhat.com>
To:     "Eric W. Biederman" <ebiederm@xmission.com>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, Wen Yang <wen.yang99@zte.com.cn>,
        majiang <ma.jiang@zte.com.cn>
Subject: Re: [RFC][PATCH 09/11] tty_io: Use do_send_sig_info in __do_SACK  to
 forcibly kill tasks
Message-ID: <20180716145540.GA20960@redhat.com>
References: <877em2jxyr.fsf_-_@xmission.com>
 <20180711024459.10654-9-ebiederm@xmission.com>
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On 07/10, Eric W. Biederman wrote:
>
> Therefore use do_send_sig_info in all cases in __do_SAK to kill
> tasks as allows for exactly what the code wants to do.

OK, but probably the changelog should also mention that now even the global
init will be killed if it has this tty opened.


> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
> ---
>  drivers/tty/tty_io.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
> index cec58c53b0c4..42ac168c2a47 100644
> --- a/drivers/tty/tty_io.c
> +++ b/drivers/tty/tty_io.c
> @@ -2747,7 +2747,7 @@ void __do_SAK(struct tty_struct *tty)
>  	do_each_pid_task(session, PIDTYPE_SID, p) {
>  		tty_notice(tty, "SAK: killed process %d (%s): by session\n",
>  			   task_pid_nr(p), p->comm);
> -		send_sig(SIGKILL, p, 1);
> +		do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);
>  	} while_each_pid_task(session, PIDTYPE_SID, p);
>  
>  	/* Now kill any processes that happen to have the tty open */
> @@ -2755,7 +2755,7 @@ void __do_SAK(struct tty_struct *tty)
>  		if (p->signal->tty == tty) {
>  			tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n",
>  				   task_pid_nr(p), p->comm);
> -			send_sig(SIGKILL, p, 1);
> +			do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);
>  			continue;
>  		}
>  		task_lock(p);
> @@ -2763,7 +2763,7 @@ void __do_SAK(struct tty_struct *tty)
>  		if (i != 0) {
>  			tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n",
>  				   task_pid_nr(p), p->comm, i - 1);
> -			force_sig(SIGKILL, p);
> +			do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);
>  		}
>  		task_unlock(p);
>  	} while_each_thread(g, p);
> -- 
> 2.17.1
>