Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753326Ab0AGSQo (ORCPT ); Thu, 7 Jan 2010 13:16:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753303Ab0AGSQn (ORCPT ); Thu, 7 Jan 2010 13:16:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:62140 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753111Ab0AGSQm (ORCPT ); Thu, 7 Jan 2010 13:16:42 -0500 Date: Thu, 7 Jan 2010 19:16:32 +0100 From: Oleg Nesterov To: Martin Schwidefsky Cc: Roland McGrath , 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) Message-ID: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100107101619.0877cf67@mschwide.boeblingen.de.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1681 Lines: 47 On 01/07, Martin Schwidefsky wrote: > > On Wed, 6 Jan 2010 13:08:12 -0800 (PST) > Roland McGrath wrote: > > > That's what tracehook_signal_handler is for. You're both doing it yourself > > in the arch code (by setting TIF_SINGLE_STEP), and then telling the generic > > code to do it (by passing stepping=1 to tracehook_signal_handler). > > Ok, so with the full utrace the semantics of tracehook_signal_handler > is more than just causing a SIGTRAP. It is an indication for a signal > AND a SIGTRAP if single-stepping is active. To make both cases work we > should stop setting TIF_SINGLE_STEP in do_signal and pass > current->thread.per_info.single_step to tracehook_signal_handler > instead of test_thread_flag(TIF_SINGLE_STEP). Can't understand why do we need TIF_SINGLE_STEP at all. Just pass current->thread.per_info.single_step to tracehook_signal_handler() ? Oleg. --- a/arch/s390/kernel/signal.c +++ b/arch/s390/kernel/signal.c @@ -504,14 +504,8 @@ void do_signal(struct pt_regs *regs) * for a normal instruction, act like we took * one for the handler setup. */ - if (current->thread.per_info.single_step) - set_thread_flag(TIF_SINGLE_STEP); - - /* - * Let tracing know that we've done the handler setup. - */ tracehook_signal_handler(signr, &info, &ka, regs, - test_thread_flag(TIF_SINGLE_STEP)); + current->thread.per_info.single_step); } return; } -- 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/