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=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D4ACEC433E6 for ; Wed, 24 Mar 2021 18:13:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9444561A24 for ; Wed, 24 Mar 2021 18:13:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237426AbhCXSM5 (ORCPT ); Wed, 24 Mar 2021 14:12:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:58190 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237397AbhCXSMS (ORCPT ); Wed, 24 Mar 2021 14:12:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616609537; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=KFO6lxfSXo+H+A/7Sv08tqh+O1ib64xN6C+hvg30WuM=; b=FTGaPvIZFutlXIy96umX4Q/5qT5ewTp5zSZFUJcCiOR7rmLeTSdn6eX3OvI7+MB93m3B8k bq9FCV2Kew6IJ//h12z2GwSkiqgAOcWcPDcdyzciZvNdTRqH2aDVmZFsBiJMsBiFa0yckn UslaKWJ+LWHTQMg9srT1bYPvKGDq4H0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-408-0hJATpJuPfeudphdNHlWWQ-1; Wed, 24 Mar 2021 14:12:15 -0400 X-MC-Unique: 0hJATpJuPfeudphdNHlWWQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 00DD61853024; Wed, 24 Mar 2021 18:12:14 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.194.218]) by smtp.corp.redhat.com (Postfix) with SMTP id DF96E10023AF; Wed, 24 Mar 2021 18:12:11 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 24 Mar 2021 19:12:13 +0100 (CET) Date: Wed, 24 Mar 2021 19:12:10 +0100 From: Oleg Nesterov To: qianli zhao Cc: christian@brauner.io, axboe@kernel.dk, "Eric W. Biederman" , Thomas Gleixner , Peter Collingbourne , linux-kernel@vger.kernel.org, Qianli Zhao Subject: Re: [PATCH V3] exit: trigger panic when global init has exited Message-ID: <20210324181209.GB13021@redhat.com> References: <20210317143805.GA5610@redhat.com> <20210318180450.GA9977@redhat.com> <20210319163225.GB19971@redhat.com> <20210322163705.GD20390@redhat.com> <20210323090035.GA25159@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 03/23, qianli zhao wrote: > > Hi,Oleg > > > You certainly don't understand me :/ > > > Please read my email you quoted below. I didn't mean the current logic. > > I meant the logic after your patch which moves atomic_dec_and_test() and > > panic() before exit_signals(). > > Sorry, I think I see what you mean now. > > You mean that after apply my patch,SIGNAL_GROUP_EXIT no longer needs > to be tested or avoid zap_pid_ns_processes()->BUG(). > Yes,your consideration is correct. OK, great > But,my patch has another purpose,protect some key variables(such > as:task->mm,task->nsproxy,etc) to recover init coredump from > fulldump,if sub-threads finish do_exit(), Yes I know. But the purpose of this SIGNAL_GROUP_EXIT check is not clear and not documented. That is why I said it should be documented at least in the changelog. Oleg.