Re: s390 user_enable_single_step() (Was: odd utrace testing results on s390x)

2010-01-05 Thread Martin Schwidefsky
On Mon, 4 Jan 2010 19:14:12 +0100 Oleg Nesterov o...@redhat.com wrote: On 01/04, Martin Schwidefsky wrote: Subject: [PATCH] fix loading of PER control registers for utrace. From: Martin Schwidefsky schwidef...@de.ibm.com If the current task enables / disables PER tracing for itself the

Re: s390 user_enable_single_step() (Was: odd utrace testing results on s390x)

2010-01-05 Thread Oleg Nesterov
On 01/05, Martin Schwidefsky wrote: On Mon, 4 Jan 2010 13:11:47 -0800 (PST) Roland McGrath rol...@redhat.com wrote: This probably means that copy_process()-user_disable_single_step() is not enough to clear the this task wants single-stepping copied from parent. I would suspect

Re: s390 user_enable_single_step() (Was: odd utrace testing results on s390x)

2010-01-05 Thread Martin Schwidefsky
On Tue, 5 Jan 2010 16:36:33 +0100 Oleg Nesterov o...@redhat.com wrote: On 01/05, Martin Schwidefsky wrote: On Mon, 4 Jan 2010 13:11:47 -0800 (PST) Roland McGrath rol...@redhat.com wrote: This probably means that copy_process()-user_disable_single_step() is not enough to clear

Re: s390 user_enable_single_step() (Was: odd utrace testing results on s390x)

2010-01-05 Thread Oleg Nesterov
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.c2010-01-05 09:49:19.541792379 -0500 @@ -384,6 +384,8 @@ void __kprobes do_single_step(struct pt_

Re: s390 user_enable_single_step() (Was: odd utrace testing results on s390x)

2010-01-05 Thread Martin Schwidefsky
On Tue, 5 Jan 2010 16:47:25 +0100 Oleg Nesterov o...@redhat.com 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

Re: s390 user_enable_single_step() (Was: odd utrace testing results on s390x)

2010-01-05 Thread Oleg Nesterov
On 01/05, Martin Schwidefsky wrote: On Tue, 5 Jan 2010 16:36:33 +0100 Oleg Nesterov o...@redhat.com wrote: For example, why do_signal() sets TIF_SINGLE_STEP? Why can't we do --- a/arch/s390/kernel/signal.c +++ b/arch/s390/kernel/signal.c @@ -500,18 +500,10 @@ void