From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C108C433E0 for ; Tue, 23 Jun 2020 21:59:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7EEE1208A9 for ; Tue, 23 Jun 2020 21:59:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388844AbgFWV7q (ORCPT ); Tue, 23 Jun 2020 17:59:46 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:51274 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387558AbgFWV7p (ORCPT ); Tue, 23 Jun 2020 17:59:45 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out03.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jnqxE-0004Hk-I8; Tue, 23 Jun 2020 15:59:44 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1jnqxD-0003OQ-N3; Tue, 23 Jun 2020 15:59:44 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Cc: , Linus Torvalds , Oleg Nesterov , Jann Horn , Kees Cook , Bernd Edlinger References: <87pn9u6h8c.fsf@x220.int.ebiederm.org> <87r1u5laac.fsf@x220.int.ebiederm.org> Date: Tue, 23 Jun 2020 16:55:20 -0500 In-Reply-To: <87r1u5laac.fsf@x220.int.ebiederm.org> (Eric W. Biederman's message of "Tue, 23 Jun 2020 16:52:43 -0500") Message-ID: <874kr1la5z.fsf_-_@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1jnqxD-0003OQ-N3;;;mid=<874kr1la5z.fsf_-_@x220.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+2UXPbTw30wEkfFjbQUHoFz2avs7xxoas= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 4/6] signal: In signal_group_exit remove the group_exit_task test X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are two places where signal_group_exit are set. In the fs/exec.c:de_thread() and in fs/coredump.c:zap_threads(). The coredump usage of group_exit_task was explicitly added[1] so that signal_group_exit() would return true during a coredump. When examining the coredump usage it turns out that SIGNAL_GROUP_COREDUMP is set in all of the same places as group_exit_task. So signal_group_exit can test SIGNAL_GROUP_COREDUMP and achieve the same results with respect to coredumps as testing group_exit_task. Similarly the exec code sets and clears SIGNAL_GROUP_DETHREAD in all of the places where group_exit_task is set and cleared. So test SIGNAL_GROUP_COREDUMP | SIGNAL_GROUP_DETHREAD instead of group_exit_task. Cc: Oleg Nesterov [1] 6cd8f0acae34 ("coredump: ensure that SIGKILL always kills the dumping thread") Signed-off-by: "Eric W. Biederman" --- include/linux/sched/signal.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 5ff8697b21cd..43822e2b63e6 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -268,8 +268,9 @@ static inline void signal_set_stop_flags(struct signal_struct *sig, /* If true, all threads except ->group_exit_task have pending SIGKILL */ static inline int signal_group_exit(const struct signal_struct *sig) { - return (sig->flags & SIGNAL_GROUP_EXIT) || - (sig->group_exit_task != NULL); + return (sig->flags & (SIGNAL_GROUP_EXIT | + SIGNAL_GROUP_COREDUMP | + SIGNAL_GROUP_DETHREAD)); } extern void flush_signals(struct task_struct *); -- 2.20.1