Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758233AbXFTPy1 (ORCPT ); Wed, 20 Jun 2007 11:54:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754317AbXFTPyT (ORCPT ); Wed, 20 Jun 2007 11:54:19 -0400 Received: from x35.xmailserver.org ([64.71.152.41]:2093 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752155AbXFTPyS (ORCPT ); Wed, 20 Jun 2007 11:54:18 -0400 X-AuthUser: davidel@xmailserver.org Date: Wed, 20 Jun 2007 08:54:11 -0700 (PDT) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: Benjamin Herrenschmidt cc: Oleg Nesterov , Linus Torvalds , Nicholas Miell , Linux Kernel Mailing List Subject: Re: Fix signalfd interaction with thread-private signals In-Reply-To: <1182311217.22337.17.camel@localhost.localdomain> Message-ID: References: <1182064500.2798.6.camel@entropy> <1182108399.3794.4.camel@entropy> <1182125303.3794.8.camel@entropy> <1182127391.26853.207.camel@localhost.localdomain> <20070619091452.GA94@tv-sign.ru> <1182302739.22337.9.camel@localhost.localdomain> <1182311217.22337.17.camel@localhost.localdomain> X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1336 Lines: 32 On Wed, 20 Jun 2007, Benjamin Herrenschmidt wrote: > On Tue, 2007-06-19 at 19:15 -0700, Davide Libenzi wrote: > > > Ok, why instead don't we go for something like the attached patch? > > We exclude sync signals from signalfd, but we don't limit signalfd to > > shared signals. Ie, we should be able to fetch a signal sent with > > sys_tkill() to threads different from "current", that otherwise we would > > not be able to fetch. > > Ben, sorry but my memory sucks ... the "notifier" thing was fine in that > > case, no? > > I'm generally nervous about the idea of letting signalfd dequeue > somebody else private signals... even if we filter out SEGV's and > friends but I'll let Linus decide there. > > Regarding the notifier, it's dodgy in most cases I'd say but I suppose > it should be allright to only worry about "current" and not the target > task there. I believe that once we exclude synchronous signals from being dequeued, we should be fine. Limiting all signals sent with sys_tkill() from being dequeued with a signalfd is a too restricting behaviour IMO. - Davide - 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/