From patchwork Tue Jun 23 21:54:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 11621873 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B7B2F60D for ; Tue, 23 Jun 2020 21:59:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A851E208A9 for ; Tue, 23 Jun 2020 21:59:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388356AbgFWV7J (ORCPT ); Tue, 23 Jun 2020 17:59:09 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:42034 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387455AbgFWV7J (ORCPT ); Tue, 23 Jun 2020 17:59:09 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out01.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jnqwd-0002ux-QC; Tue, 23 Jun 2020 15:59:07 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1jnqwc-0000mu-Qc; Tue, 23 Jun 2020 15:59:07 -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 16:54:43 -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: <87a70tla70.fsf_-_@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 X-XM-SPF: eid=1jnqwc-0000mu-Qc;;;mid=<87a70tla70.fsf_-_@x220.int.ebiederm.org>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+kkhDUBissrPENOFQGDqoexIjbrQanp20= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on sa07.xmission.com X-Spam-Level: X-Spam-Status: No, score=-0.2 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TooManySym_01 autolearn=disabled version=3.4.2 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 0; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: ; sa07 0; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ; X-Spam-Relay-Country: X-Spam-Timing: total 540 ms - load_scoreonly_sql: 0.11 (0.0%), signal_user_changed: 215 (39.9%), b_tie_ro: 213 (39.5%), parse: 1.09 (0.2%), extract_message_metadata: 12 (2.2%), get_uri_detail_list: 1.34 (0.2%), tests_pri_-1000: 15 (2.8%), tests_pri_-950: 1.44 (0.3%), tests_pri_-900: 1.10 (0.2%), tests_pri_-90: 82 (15.2%), check_bayes: 81 (14.9%), b_tokenize: 7 (1.3%), b_tok_get_all: 6 (1.1%), b_comp_prob: 2.1 (0.4%), b_tok_touch_all: 62 (11.5%), b_finish: 0.96 (0.2%), tests_pri_0: 192 (35.5%), check_dkim_signature: 1.17 (0.2%), check_dkim_adsp: 2.9 (0.5%), poll_dns_idle: 0.53 (0.1%), tests_pri_10: 2.3 (0.4%), tests_pri_500: 14 (2.5%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH v2 3/6] signal: Implement SIGNAL_GROUP_DETHREAD X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org To allow signal_group_exit to be simplfied so that it can only test signal->flags. Add a new flag SIGNAL_GROUP_DETHREAD, that is set and cleared where de_thread sets and clears group_exit_task today. Signed-off-by: "Eric W. Biederman" --- fs/exec.c | 3 +++ include/linux/sched/signal.h | 1 + 2 files changed, 4 insertions(+) diff --git a/fs/exec.c b/fs/exec.c index 33b5d9229c01..9c4c1ab8f715 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1145,6 +1145,7 @@ static int de_thread(struct task_struct *tsk) return -EAGAIN; } + sig->flags |= SIGNAL_GROUP_DETHREAD; sig->group_exit_task = tsk; sig->notify_count = zap_other_threads(tsk); if (!thread_group_leader(tsk)) @@ -1244,6 +1245,7 @@ static int de_thread(struct task_struct *tsk) } spin_lock_irq(lock); + sig->flags &= ~SIGNAL_GROUP_DETHREAD; sig->group_exit_task = NULL; sig->notify_count = 0; spin_unlock_irq(lock); @@ -1259,6 +1261,7 @@ static int de_thread(struct task_struct *tsk) /* protects against exit_notify() and __exit_signal() */ read_lock_irq(&tasklist_lock); spin_lock(lock); + sig->flags &= ~SIGNAL_GROUP_DETHREAD; sig->group_exit_task = NULL; sig->notify_count = 0; spin_unlock(lock); diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index b4f36a11be5e..5ff8697b21cd 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -253,6 +253,7 @@ struct signal_struct { /* Signal group actions. */ #define SIGNAL_GROUP_EXIT 0x00000100 /* group exit in progress */ #define SIGNAL_GROUP_COREDUMP 0x00000200 /* coredump in progress */ +#define SIGNAL_GROUP_DETHREAD 0x00000400 /* exec de_thread in progress */ /* Flags applicable to the entire signal group. */ #define SIGNAL_UNKILLABLE 0x00001000 /* for init: ignore fatal signals */