From: Oleg Nesterov <oleg@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: Denys Vlasenko <vda.linux@googlemail.com>,
Roland McGrath <roland@redhat.com>,
jan.kratochvil@redhat.com, linux-kernel@vger.kernel.org,
torvalds@linux-foundation.org, akpm@linux-foundation.org
Subject: Re: [PATCH 1/1] ptrace: make sure do_wait() won't hang after PTRACE_ATTACH
Date: Mon, 14 Feb 2011 18:23:58 +0100 [thread overview]
Message-ID: <20110214172358.GB14528@redhat.com> (raw)
In-Reply-To: <20110214163346.GZ18742@htj.dyndns.org>
On 02/14, Tejun Heo wrote:
>
> On Mon, Feb 14, 2011 at 05:15:15PM +0100, Oleg Nesterov wrote:
> > > > PTRACE_CONT in this situation would do the same.
> > >
> > > This can be fixed by updating strace, right? strace can look at the
> > > wait(2) exit code and if the tracee stopped for group stop, wait for
> > > the tracee to be continued instead of issuing PTRACE_SYSCALL.
> >
> > Yes, in this particular case strace could be more clever.
> >
> > But. The tracee should react to SIGCONT after that, this means we
> > shouldn't "delay" this stop or force the TASK_TRACED state.
>
> Yeap, which is achievable by treating group stop differently from
> ptrace traps and make it proceed to TASK_TRACED only if ptrace wants
> to issue commands.
Yes, agreed. And this is exactly what we currently do. Except, as you
pointed out, the simple s/STOPPED/TRACED/ change is buggy. But the fix
you suggested should be almost invisible to the userland.
> (reiterating just to make sure there's no
> misunderstanding)
The same from my side ;)
Oleg.
next prev parent reply other threads:[~2011-02-14 17:32 UTC|newest]
Thread overview: 160+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-28 15:08 [PATCHSET] ptrace,signal: group stop / ptrace updates Tejun Heo
2011-01-28 15:08 ` [PATCH 01/10] signal: fix SIGCONT notification code Tejun Heo
2011-01-28 15:08 ` [PATCH 02/10] ptrace: remove the extra wake_up_process() from ptrace_detach() Tejun Heo
2011-01-28 18:46 ` Roland McGrath
2011-01-31 10:38 ` Tejun Heo
2011-02-01 10:26 ` [PATCH] ptrace: use safer wake up on ptrace_detach() Tejun Heo
2011-02-01 13:40 ` Oleg Nesterov
2011-02-01 15:07 ` Tejun Heo
2011-02-01 19:17 ` Oleg Nesterov
2011-02-02 5:31 ` Roland McGrath
2011-02-02 10:35 ` Tejun Heo
2011-02-02 0:27 ` Andrew Morton
2011-02-02 5:33 ` Roland McGrath
2011-02-02 5:38 ` Andrew Morton
2011-02-02 10:34 ` Tejun Heo
2011-02-02 19:33 ` Andrew Morton
2011-02-02 20:01 ` Tejun Heo
2011-02-02 21:40 ` Oleg Nesterov
2011-02-02 5:29 ` Roland McGrath
2011-02-02 5:28 ` [PATCH 02/10] ptrace: remove the extra wake_up_process() from ptrace_detach() Roland McGrath
2011-01-28 15:08 ` [PATCH 03/10] signal: remove superflous try_to_freeze() loop in do_signal_stop() Tejun Heo
2011-01-28 18:46 ` Roland McGrath
2011-01-28 15:08 ` [PATCH 04/10] ptrace: kill tracehook_notify_jctl() Tejun Heo
2011-01-28 21:09 ` Roland McGrath
2011-01-28 15:08 ` [PATCH 05/10] ptrace: add @why to ptrace_stop() Tejun Heo
2011-01-28 18:48 ` Roland McGrath
2011-01-28 15:08 ` [PATCH 06/10] signal: fix premature completion of group stop when interfered by ptrace Tejun Heo
2011-01-28 21:22 ` Roland McGrath
2011-01-31 11:00 ` Tejun Heo
2011-02-02 5:44 ` Roland McGrath
2011-02-02 10:56 ` Tejun Heo
2011-01-28 15:08 ` [PATCH 07/10] signal: use GROUP_STOP_PENDING to stop once for a single group stop Tejun Heo
2011-01-28 15:08 ` [PATCH 08/10] ptrace: participate in group stop from ptrace_stop() iff the task is trapping for " Tejun Heo
2011-01-28 21:30 ` Roland McGrath
2011-01-31 11:26 ` Tejun Heo
2011-02-02 5:57 ` Roland McGrath
2011-02-02 10:53 ` Tejun Heo
2011-02-03 10:02 ` Tejun Heo
2011-02-01 19:36 ` Oleg Nesterov
2011-01-28 15:08 ` [PATCH 09/10] ptrace: make do_signal_stop() use ptrace_stop() if the task is being ptraced Tejun Heo
2011-01-28 15:08 ` [PATCH 10/10] ptrace: clean transitions between TASK_STOPPED and TRACED Tejun Heo
2011-02-03 20:41 ` [PATCH 0/1] (Was: ptrace: clean transitions between TASK_STOPPED and TRACED) Oleg Nesterov
2011-02-03 20:41 ` [PATCH 1/1] ptrace: make sure do_wait() won't hang after PTRACE_ATTACH Oleg Nesterov
2011-02-03 21:36 ` Roland McGrath
2011-02-03 21:44 ` Oleg Nesterov
2011-02-04 10:53 ` Tejun Heo
2011-02-04 13:04 ` Oleg Nesterov
2011-02-04 14:48 ` Tejun Heo
2011-02-04 17:06 ` Oleg Nesterov
2011-02-05 13:39 ` Tejun Heo
2011-02-07 13:42 ` Oleg Nesterov
2011-02-07 14:11 ` Tejun Heo
2011-02-07 15:37 ` Oleg Nesterov
2011-02-07 16:31 ` Tejun Heo
2011-02-07 17:48 ` Oleg Nesterov
2011-02-09 14:18 ` Tejun Heo
2011-02-09 14:21 ` Tejun Heo
2011-02-09 21:25 ` Oleg Nesterov
2011-02-13 23:01 ` Denys Vlasenko
2011-02-14 9:03 ` Jan Kratochvil
2011-02-14 11:39 ` Denys Vlasenko
2011-02-14 17:32 ` Oleg Nesterov
2011-02-14 16:01 ` Oleg Nesterov
2011-02-26 3:59 ` Pavel Machek
2011-02-14 15:51 ` Oleg Nesterov
2011-02-14 14:50 ` Tejun Heo
2011-02-14 18:53 ` Oleg Nesterov
2011-02-13 22:25 ` Denys Vlasenko
2011-02-14 15:13 ` Tejun Heo
2011-02-14 16:15 ` Oleg Nesterov
2011-02-14 16:33 ` Tejun Heo
2011-02-14 17:23 ` Oleg Nesterov [this message]
2011-02-14 17:20 ` Denys Vlasenko
2011-02-14 17:30 ` Tejun Heo
2011-02-14 17:45 ` Oleg Nesterov
2011-02-14 17:54 ` Denys Vlasenko
2011-02-21 15:16 ` Tejun Heo
2011-02-21 15:28 ` Oleg Nesterov
2011-02-21 16:11 ` [pseudo patch] ptrace should respect the group stop Oleg Nesterov
2011-02-22 16:24 ` [PATCH 1/1] ptrace: make sure do_wait() won't hang after PTRACE_ATTACH Tejun Heo
2011-02-24 21:08 ` Oleg Nesterov
2011-02-25 15:45 ` Tejun Heo
2011-02-25 17:42 ` Roland McGrath
2011-02-28 15:23 ` Oleg Nesterov
2011-02-14 17:51 ` Oleg Nesterov
2011-02-14 18:55 ` Denys Vlasenko
2011-02-14 19:01 ` Oleg Nesterov
2011-02-14 19:42 ` Denys Vlasenko
2011-02-14 20:01 ` Oleg Nesterov
2011-02-15 15:24 ` Tejun Heo
2011-02-15 15:58 ` Oleg Nesterov
2011-02-15 17:31 ` Roland McGrath
2011-02-15 20:27 ` Oleg Nesterov
2011-02-18 17:02 ` Tejun Heo
2011-02-18 19:37 ` Oleg Nesterov
2011-02-21 16:22 ` Tejun Heo
2011-02-21 16:49 ` Oleg Nesterov
2011-02-21 16:59 ` Tejun Heo
2011-02-23 19:31 ` Oleg Nesterov
2011-02-25 15:10 ` Tejun Heo
2011-02-24 20:29 ` Oleg Nesterov
2011-02-25 15:51 ` Tejun Heo
2011-02-26 2:48 ` Denys Vlasenko
2011-02-28 12:56 ` Tejun Heo
2011-02-28 13:16 ` Denys Vlasenko
2011-02-28 13:29 ` Tejun Heo
2011-02-28 13:41 ` Denys Vlasenko
2011-02-28 13:53 ` Tejun Heo
2011-02-28 14:25 ` Denys Vlasenko
2011-02-28 14:39 ` Tejun Heo
2011-02-28 16:48 ` Oleg Nesterov
2011-02-28 14:36 ` Oleg Nesterov
2011-02-16 21:51 ` Jan Kratochvil
2011-02-17 3:37 ` Denys Vlasenko
2011-02-17 19:19 ` Oleg Nesterov
2011-02-18 21:11 ` Jan Kratochvil
2011-02-19 20:16 ` Oleg Nesterov
2011-02-17 16:49 ` Oleg Nesterov
2011-02-17 18:58 ` Roland McGrath
2011-02-17 19:33 ` Oleg Nesterov
2011-02-18 21:34 ` Jan Kratochvil
2011-02-19 20:06 ` Oleg Nesterov
2011-02-20 9:40 ` Jan Kratochvil
2011-02-20 17:06 ` Denys Vlasenko
2011-02-20 17:48 ` Oleg Nesterov
2011-02-20 19:10 ` Jan Kratochvil
2011-02-20 19:16 ` Oleg Nesterov
2011-02-20 17:16 ` Oleg Nesterov
2011-02-20 18:52 ` Jan Kratochvil
2011-02-20 20:38 ` Oleg Nesterov
2011-02-20 21:06 ` `(T) stopped' preservation after _exit() [Re: [PATCH 1/1] ptrace: make sure do_wait() won't hang after PTRACE_ATTACH] Jan Kratochvil
2011-02-20 21:19 ` Oleg Nesterov
2011-02-20 21:20 ` [PATCH 1/1] ptrace: make sure do_wait() won't hang after PTRACE_ATTACH Jan Kratochvil
2011-02-21 14:23 ` Oleg Nesterov
2011-02-23 16:44 ` Jan Kratochvil
2011-02-14 15:31 ` Oleg Nesterov
2011-02-14 17:24 ` Denys Vlasenko
2011-02-14 17:39 ` Oleg Nesterov
2011-02-14 17:57 ` Denys Vlasenko
2011-02-14 18:00 ` Oleg Nesterov
2011-02-14 18:06 ` Oleg Nesterov
2011-02-14 18:59 ` Denys Vlasenko
2011-02-13 21:24 ` Denys Vlasenko
2011-02-14 15:06 ` Oleg Nesterov
2011-02-14 15:19 ` Tejun Heo
2011-02-14 16:20 ` Oleg Nesterov
2011-02-14 17:05 ` Denys Vlasenko
2011-02-14 17:18 ` Oleg Nesterov
2011-01-28 16:54 ` [PATCHSET] ptrace,signal: group stop / ptrace updates Ingo Molnar
2011-01-28 17:41 ` Thomas Gleixner
2011-01-28 18:04 ` Anca Emanuel
2011-01-28 18:36 ` Mathieu Desnoyers
2011-01-28 17:55 ` Oleg Nesterov
2011-01-28 18:29 ` Bash not reacting to Ctrl-C Ingo Molnar
2011-02-05 20:34 ` Oleg Nesterov
2011-02-07 13:08 ` Oleg Nesterov
2011-02-09 6:17 ` Michael Witten
2011-02-09 14:53 ` Ingo Molnar
2011-02-09 19:37 ` Michael Witten
2011-02-11 14:41 ` Pavel Machek
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