Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754158Ab0AGVom (ORCPT ); Thu, 7 Jan 2010 16:44:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754131Ab0AGVok (ORCPT ); Thu, 7 Jan 2010 16:44:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52521 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754127Ab0AGVoi (ORCPT ); Thu, 7 Jan 2010 16:44:38 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: Roland McGrath To: Oleg Nesterov X-Fcc: ~/Mail/linus Cc: Martin Schwidefsky , caiqian@redhat.com, Heiko Carstens , Jan Kratochvil , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, utrace-devel@redhat.com Subject: Re: s390 && user_enable_single_step() (Was: odd utrace testing results on s390x) In-Reply-To: Oleg Nesterov's message of Thursday, 7 January 2010 19:16:32 +0100 <20100107181632.GC13300@redhat.com> References: <1503844142.2061111261478093776.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> <1257887498.2061171261478252049.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> <20100104155225.GA16650@redhat.com> <20100104171626.22ea2d9c@mschwide.boeblingen.de.ibm.com> <20100104181412.GA21146@redhat.com> <20100104211147.4CC94D532@magilla.sf.frob.com> <20100105105030.66bb8a0a@mschwide.boeblingen.de.ibm.com> <20100105153633.GA9376@redhat.com> <20100106210812.E03A1134D@magilla.sf.frob.com> <20100107101619.0877cf67@mschwide.boeblingen.de.ibm.com> <20100107181632.GC13300@redhat.com> X-Antipastobozoticataclysm: When George Bush projectile vomits antipasto on the Japanese. Message-Id: <20100107214429.6388A7300@magilla.sf.frob.com> Date: Thu, 7 Jan 2010 13:44:29 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 794 Lines: 23 > Can't understand why do we need TIF_SINGLE_STEP at all. I think you mean "why we need to set it in do_signal" here, not "why do we need it to exist at all". > Just pass current->thread.per_info.single_step to > tracehook_signal_handler() ? Yes. I believe this is what Martin meant, and it's what I meant to endorse. do_signal should not do anything with TIF_SINGLE_STEP at all. Its only purpose should be to communicate from the low-level trap assembly code up to the return-to-user assembly code so it calls do_single_step. Thanks, Roland -- 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/