Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936495AbXFFWo2 (ORCPT ); Wed, 6 Jun 2007 18:44:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965364AbXFFWny (ORCPT ); Wed, 6 Jun 2007 18:43:54 -0400 Received: from ozlabs.org ([203.10.76.45]:60831 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965232AbXFFWnx (ORCPT ); Wed, 6 Jun 2007 18:43:53 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18023.14494.889739.567439@cargo.ozlabs.ibm.com> Date: Thu, 7 Jun 2007 08:43:42 +1000 From: Paul Mackerras To: Jeff Dike Cc: Benjamin Herrenschmidt , Nicholas Miell , Davide Libenzi , Linus Torvalds , Linux Kernel list , Andrew Morton Subject: Re: signalfd API issues (was Re: [PATCH/RFC] signal races/bugs, losing TIF_SIGPENDING and other woes) In-Reply-To: <20070606125259.GA5491@c2.user-mode-linux.org> References: <1181013756.31677.123.camel@localhost.localdomain> <1181023787.2785.14.camel@entropy> <1181028453.31677.127.camel@localhost.localdomain> <1181087462.2788.8.camel@entropy> <1181088936.2788.10.camel@entropy> <1181091523.2788.28.camel@entropy> <1181098204.31677.158.camel@localhost.localdomain> <20070606125259.GA5491@c2.user-mode-linux.org> X-Mailer: VM 7.19 under Emacs 21.4.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 856 Lines: 21 Jeff Dike writes: > On Wed, Jun 06, 2007 at 12:50:04PM +1000, Benjamin Herrenschmidt wrote: > > Yeah, synchronous signals should probably never be delivered to another > > process, even via signalfd. There's no point delivering a SEGV to > > somebody else :-) > > Sure there is. UML does exactly that - intercepting child signals > (including SEGV) with wait. What Ben was talking about was stealing a synchronous SEGV from a task without stopping it, and as Ben says that makes no sense. Intercepting a signal and stopping the task is reasonable, and that is what ptrace does, and I assume also UML. Paul. - 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/