From owner-freebsd-hackers@freebsd.org Tue Aug 28 17:27:25 2018 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6454010924BE for ; Tue, 28 Aug 2018 17:27:25 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from hz.grosbein.net (hz.grosbein.net [IPv6:2a01:4f8:d12:604::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "hz.grosbein.net", Issuer "hz.grosbein.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id DB1038DF88; Tue, 28 Aug 2018 17:27:24 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (eg.sd.rdtc.ru [IPv6:2a03:3100:c:13:0:0:0:5]) by hz.grosbein.net (8.15.2/8.15.2) with ESMTPS id w7SHRHhI006294 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 28 Aug 2018 19:27:17 +0200 (CEST) (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: warmwhitewolf@gmail.com Received: from [10.58.0.4] ([10.58.0.4]) by eg.sd.rdtc.ru (8.15.2/8.15.2) with ESMTPS id w7SHR6Pg089329 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Wed, 29 Aug 2018 00:27:06 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: angel(2) system call, the quest for immortality, aka kill(2) with SIGSTOP/SIGKILL will *not* work To: Warm White Wolf , asomers@freebsd.org, freebsd-hackers@freebsd.org References: From: Eugene Grosbein Message-ID: Date: Wed, 29 Aug 2018 00:27:00 +0700 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=0.3 required=5.0 tests=BAYES_00,LOCAL_FROM,SPF_PASS autolearn=no autolearn_force=no version=3.4.1 X-Spam-Report: * -0.0 SPF_PASS SPF: sender matches SPF record * -2.3 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 2.6 LOCAL_FROM From my domains X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on hz.grosbein.net X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Aug 2018 17:27:25 -0000 28.08.2018 23:36, Warm White Wolf wrote: > Seriously : suppose your well crafted, eventually audited program, is more > important than > your whole informatic system, perhaps the raison d'etre of your business. > You want to live, > more than the 1% errors of your sysadmins. > > Ludic : you have an account in the Unix machines at your university. You > wrote your small > HTTPD, and you want that your sysadmins won't kill your power-httpd. > > fork(void) was pretty extremy at it's time... > > As a power Unix-user, a config option for the kernel, at compile-time, can > be provided... This does not protect a process from power outage. And this does not (and should not) protect a process from system shutdown/reboot to install critical updates, for example. Well crafted programm must be designed to be ready to such events, be able to recover and continue execution after restart. And well crafted operating systems do not kill processes with SIGKILL easily, they use other means to inform processes to terminate execution, so is FreeBSD.