From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 5 Jan 2010 16:50:53 +0100 From: Martin Schwidefsky Subject: Re: s390 && user_enable_single_step() (Was: odd utrace testing results on s390x) Message-ID: <20100105165053.3e75e438@mschwide.boeblingen.de.ibm.com> In-Reply-To: <20100105154725.GB9376@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> <20100105154725.GB9376@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Oleg Nesterov Cc: Roland McGrath , caiqian@redhat.com, Heiko Carstens , Jan Kratochvil , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, utrace-devel@redhat.com List-ID: On Tue, 5 Jan 2010 16:47:25 +0100 Oleg Nesterov wrote: > On 01/05, Oleg Nesterov wrote: > > > > Anyway. I modified the debugging patch a bit: > > > > --- K/arch/s390/kernel/traps.c~ 2009-12-22 10:41:52.909174198 -0500 > > +++ K/arch/s390/kernel/traps.c 2010-01-05 09:49:19.541792379 -0500 > > @@ -384,6 +384,8 @@ void __kprobes do_single_step(struct pt_ > > } > > if (tracehook_consider_fatal_signal(current, SIGTRAP)) > > force_sig(SIGTRAP, current); > > + else > > + printk("XXX: %d %d\n", current->pid, test_thread_flag(TIF_SINGLE_STEP)); > > } > > > > static void default_trap_handler(struct pt_regs * regs, long interruption_code) > > ------------------------------------------------------------------------------- > > Ah, please ignore. I guess TIF_SINGLE_STEP was already cleared by the caller > in entry.S Yes, TIF_SINGLE_STEP is checked in entry.S and cleared before do_signal is called. That is the "ni" instruction at sysc_singlestep and sysc_sigpending. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.