Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270630AbTHCVG0 (ORCPT ); Sun, 3 Aug 2003 17:06:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271233AbTHCVG0 (ORCPT ); Sun, 3 Aug 2003 17:06:26 -0400 Received: from pc1-cwma1-5-cust4.swan.cable.ntl.com ([80.5.120.4]:47001 "EHLO lxorguk.ukuu.org.uk") by vger.kernel.org with ESMTP id S270630AbTHCVEd (ORCPT ); Sun, 3 Aug 2003 17:04:33 -0400 Subject: Re: [PATCH] bug in setpgid()? process groups and thread groups From: Alan Cox To: Florian Weimer Cc: Roland McGrath , Jeremy Fitzhardinge , Ulrich Drepper , Linux Kernel Mailing List , Andrew Morton In-Reply-To: <8765lfxl21.fsf@deneb.enyo.de> References: <200308021908.h72J82x10422@magilla.sf.frob.com> <1059857483.20306.6.camel@dhcp22.swansea.linux.org.uk> <8765lfxl21.fsf@deneb.enyo.de> Content-Type: text/plain Content-Transfer-Encoding: 7bit Organization: Message-Id: <1059944423.31901.8.camel@dhcp22.swansea.linux.org.uk> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 (1.2.2-5) Date: 03 Aug 2003 22:00:24 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1159 Lines: 28 On Sul, 2003-08-03 at 08:22, Florian Weimer wrote: > Alan Cox writes: > > > #1 Lots of non posix afflicted intelligent programmers use the per > > thread uid stuff in daemons. Its really really useful > > It doesn't work reliably because the threading implementation might > have to send signals which the current combination of credentials does > not allow. It works beautifully. Its very effective for clone() using applications > IMHO, POSIX is wrong to favor process attributes so strongly. It > wouldn't be a problem if there were other ways to pass these implicit > parameters (such as thread-specific attributes, or, even better, > syscall arguments). But often there isn't. The restriction in this case comes from a more fundamental thing - posix pthreads is full of compromises so it can be done in user space. Clearly you can't split uid's in user space very sanely. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/