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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 F218EC49EA7 for ; Thu, 24 Jun 2021 19:02:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DDDC9613C3 for ; Thu, 24 Jun 2021 19:02:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232724AbhFXTEv (ORCPT ); Thu, 24 Jun 2021 15:04:51 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:36650 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232620AbhFXTEs (ORCPT ); Thu, 24 Jun 2021 15:04:48 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1lwUcL-0009Y8-Mg; Thu, 24 Jun 2021 13:02:25 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:47202 helo=email.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1lwUcK-003HTb-23; Thu, 24 Jun 2021 13:02:24 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Linus Torvalds Cc: Al Viro , Michael Schmitz , linux-arch , Jens Axboe , Oleg Nesterov , Linux Kernel Mailing List , Richard Henderson , Ivan Kokshaysky , Matt Turner , alpha , Geert Uytterhoeven , linux-m68k , Arnd Bergmann , Ley Foon Tan , Tejun Heo , Kees Cook References: <87sg1lwhvm.fsf@disp2133> <6e47eff8-d0a4-8390-1222-e975bfbf3a65@gmail.com> <924ec53c-2fd9-2e1c-bbb1-3fda49809be4@gmail.com> <87eed4v2dc.fsf@disp2133> <5929e116-fa61-b211-342a-c706dcb834ca@gmail.com> <87fsxjorgs.fsf@disp2133> <87a6njf0ia.fsf@disp2133> <87tulpbp19.fsf@disp2133> <87zgvgabw1.fsf@disp2133> <875yy3850g.fsf_-_@disp2133> Date: Thu, 24 Jun 2021 14:02:16 -0500 In-Reply-To: <875yy3850g.fsf_-_@disp2133> (Eric W. Biederman's message of "Thu, 24 Jun 2021 13:57:35 -0500") Message-ID: <874kdn6q87.fsf_-_@disp2133> 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=1lwUcK-003HTb-23;;;mid=<874kdn6q87.fsf_-_@disp2133>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/I97aJ4pXlAoUyWwPqGNNIcVUdMFX/Zgo= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH 6/9] signal: Fold do_group_exit into get_signal fixing io_uring threads X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Forld do_group_exit into get_signal as it is the last caller. Move the group_exit logic above the PF_IO_WORKER exit, ensuring that if an PF_IO_WORKER catches SIGKILL every thread in the thread group will exit not just the the PF_IO_WORKER. Now that the information is easily available only set PF_SIGNALED when it was a signal that caused the exit. Signed-off-by: "Eric W. Biederman" --- include/linux/sched/task.h | 1 - kernel/exit.c | 31 ------------------------------- kernel/signal.c | 35 +++++++++++++++++++++++++---------- 3 files changed, 25 insertions(+), 42 deletions(-) diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index ef02be869cf2..45525512e3d0 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -77,7 +77,6 @@ static inline void exit_thread(struct task_struct *tsk) { } #endif -extern void do_group_exit(int); extern void exit_files(struct task_struct *); extern void exit_itimers(struct signal_struct *); diff --git a/kernel/exit.c b/kernel/exit.c index 921519d80b56..635f434122b7 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -892,37 +892,6 @@ SYSCALL_DEFINE1(exit, int, error_code) do_exit((error_code&0xff)<<8); } -/* - * Take down every thread in the group. This is called by fatal signals - * as well as by sys_exit_group (below). - */ -void -do_group_exit(int exit_code) -{ - struct signal_struct *sig = current->signal; - - BUG_ON(exit_code & 0x80); /* core dumps don't get here */ - - if (signal_group_exit(sig)) - exit_code = sig->group_exit_code; - else if (!thread_group_empty(current)) { - struct sighand_struct *const sighand = current->sighand; - - spin_lock_irq(&sighand->siglock); - if (signal_group_exit(sig)) - /* Another thread got here before we took the lock. */ - exit_code = sig->group_exit_code; - else { - sig->group_exit_code = exit_code; - sig->flags = SIGNAL_GROUP_EXIT; - zap_other_threads(current); - } - spin_unlock_irq(&sighand->siglock); - } - - do_exit(exit_code); - /* NOTREACHED */ -} /* * this kills every thread in the thread group. Note that any externally diff --git a/kernel/signal.c b/kernel/signal.c index c79c010ca5f3..95a076af600a 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2646,6 +2646,7 @@ bool get_signal(struct ksignal *ksig) { struct sighand_struct *sighand = current->sighand; struct signal_struct *signal = current->signal; + int exit_code; int signr; if (unlikely(current->task_works)) @@ -2848,8 +2849,6 @@ bool get_signal(struct ksignal *ksig) /* * Anything else is fatal, maybe with a core dump. */ - current->flags |= PF_SIGNALED; - if (sig_kernel_coredump(signr)) { if (print_fatal_signals) print_fatal_signal(ksig->info.si_signo); @@ -2857,14 +2856,33 @@ bool get_signal(struct ksignal *ksig) /* * If it was able to dump core, this kills all * other threads in the group and synchronizes with - * their demise. If we lost the race with another - * thread getting here, it set group_exit_code - * first and our do_group_exit call below will use - * that value and ignore the one we pass it. + * their demise. If another thread makes it + * to do_coredump first, it will set group_exit_code + * which will be passed to do_exit. */ do_coredump(&ksig->info); } + /* + * Death signals, no core dump. + */ + exit_code = signr; + if (signal_group_exit(signal)) { + exit_code = signal->group_exit_code; + } else { + spin_lock_irq(&sighand->siglock); + if (signal_group_exit(signal)) { + /* Another thread got here before we took the lock. */ + exit_code = signal->group_exit_code; + } else { + start_group_exit_locked(signal, exit_code); + } + spin_unlock_irq(&sighand->siglock); + } + + if (exit_code & 0x7f) + current->flags |= PF_SIGNALED; + /* * PF_IO_WORKER threads will catch and exit on fatal signals * themselves. They have cleanup that must be performed, so @@ -2873,10 +2891,7 @@ bool get_signal(struct ksignal *ksig) if (current->flags & PF_IO_WORKER) goto out; - /* - * Death signals, no core dump. - */ - do_group_exit(ksig->info.si_signo); + do_exit(exit_code); /* NOTREACHED */ } spin_unlock_irq(&sighand->siglock); -- 2.20.1