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 D80B9C433E6 for ; Wed, 10 Mar 2021 17:33:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ABAF261583 for ; Wed, 10 Mar 2021 17:33:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232697AbhCJRdD (ORCPT ); Wed, 10 Mar 2021 12:33:03 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:50760 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233145AbhCJRcq (ORCPT ); Wed, 10 Mar 2021 12:32:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615397566; 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=58ntsYjRUyWKxftkmOsw5t+goH6gjLTWKbgL1ZhWpSk=; b=fECFOlOXLtVx0jd3OQ5xJLvPkPi5UuWo9/epZ0dD9MBcELxUJWzvnHln4/2s5RPqu/E6Xd rJwgtLzoznwkBwDD2XKrVox430DayTjX4qRtxfrl7crNuZazZHCxPQBUghhJ+Ej1CvbRFQ 0Y0lqwywCukXBlkGGK95CDrVzkIlZ48= 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-328-OJQdNBbIM46PZQ8s5JxdEQ-1; Wed, 10 Mar 2021 12:32:42 -0500 X-MC-Unique: OJQdNBbIM46PZQ8s5JxdEQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DA599107466D; Wed, 10 Mar 2021 17:32:40 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.192.38]) by smtp.corp.redhat.com (Postfix) with SMTP id 9048960C5F; Wed, 10 Mar 2021 17:32:38 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 10 Mar 2021 18:32:40 +0100 (CET) Date: Wed, 10 Mar 2021 18:32:37 +0100 From: Oleg Nesterov To: "Eric W. Biederman" Cc: qianli zhao , christian@brauner.io, axboe@kernel.dk, Thomas Gleixner , Peter Collingbourne , linux-kernel@vger.kernel.org, Qianli Zhao Subject: Re: [PATCH] exit: trigger panic when init process is set to SIGNAL_GROUP_EXIT Message-ID: <20210310173236.GB8973@redhat.com> References: <1615296712-175334-1-git-send-email-zhaoqianligood@gmail.com> <20210309182657.GA1408@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 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/10, Eric W. Biederman wrote: > > /* If global init has exited, > * panic immediately to get a useable coredump. > */ > if (unlikely(is_global_init(tsk) && > (thread_group_empty(tsk) || > (tsk->signal->flags & SIGNAL_GROUP_EXIT)))) { > panic("Attempted to kill init! exitcode=0x%08x\n", > tsk->signal->group_exit_code ?: (int)code); > } > > The thread_group_empty test is needed to handle single threaded > inits. But we can't rely on thread_group_empty(). Just suppose that the main thread exit first, then the 2nd (last) thread exits too. Oleg.