From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753226AbeAQMjr (ORCPT + 1 other); Wed, 17 Jan 2018 07:39:47 -0500 Received: from mail-he1eur01on0122.outbound.protection.outlook.com ([104.47.0.122]:27648 "EHLO EUR01-HE1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752963AbeAQMjp (ORCPT ); Wed, 17 Jan 2018 07:39:45 -0500 Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=ktkhai@virtuozzo.com; Subject: [PATCH v2 1/3] Revert "do_SAK: Don't recursively take the tasklist_lock" From: Kirill Tkhai To: gregkh@linuxfoundation.org, jslaby@suse.com, oleg@redhat.com, ebiederm@xmission.com, ktkhai@virtuozzo.com Cc: linux-kernel@vger.kernel.org Date: Wed, 17 Jan 2018 15:39:32 +0300 Message-ID: <151619277281.5683.16110625178528288163.stgit@localhost.localdomain> In-Reply-To: <151619233415.5683.18062849657787533510.stgit@localhost.localdomain> References: <151619233415.5683.18062849657787533510.stgit@localhost.localdomain> User-Agent: StGit/0.18 MIME-Version: 1.0 Content-Type: text/plain; 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Also, the problem of force_sig() is it clears SIGNAL_UNKILLABLE flag, thus even global init may be killed by __do_SAK(), which is definitely not the expected behavior. Came from discussion in "tty: Iterate only thread group leaders in __do_SAK()" https://lkml.org/lkml/2018/1/11/492 Suggested-by: Oleg Nesterov Signed-off-by: Kirill Tkhai --- drivers/tty/tty_io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index dc60aeea87d8..84715ba1aee2 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2737,7 +2737,7 @@ 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); + send_sig(SIGKILL, p, 1); } task_unlock(p); } while_each_thread(g, p);