From: Oleg Nesterov <oleg@redhat.com>
To: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Tejun Heo <tj@kernel.org>,
jan.kratochvil@redhat.com, linux-kernel@vger.kernel.org,
torvalds@linux-foundation.org, akpm@linux-foundation.org,
indan@nul.nu, bdonlan@gmail.com, pedro@codesourcery.com
Subject: Re: [PATCHSET ptrace] ptrace: implement PTRACE_SEIZE/INTERRUPT and group stop notification, take#4
Date: Fri, 3 Jun 2011 17:46:32 +0200 [thread overview]
Message-ID: <20110603154632.GD23757@redhat.com> (raw)
In-Reply-To: <201106031357.02859.vda.linux@googlemail.com>
On 06/03, Denys Vlasenko wrote:
>
> On Friday 03 June 2011 03:24, Tejun Heo wrote:
> >
> > Anyways, let's think about that, but SIGSTOP on clone is closely
> > linked to why SEIZE is used in the first place and I currently lean
> > toward tying it to SEIZE.
>
> Ok.
>
> SIGSTOP on clone is less problematic because in practice it's
> rather hard to send a real SIGSTOP to a thread which is _just_ created.
> So the race window is mostly theoretical
It is not. The new child can dequeue a signal which was sent to the
process (thread group). How the tracer can distinguish? Also, SIGSTOP
can be sent to pgrp and the new tracee can be forked.
I think that SEIZE should never send SIGSTOP on auto-attach, without
any options.
Oleg.
next prev parent reply other threads:[~2011-06-03 15:48 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-29 23:12 [PATCHSET ptrace] ptrace: implement PTRACE_SEIZE/INTERRUPT and group stop notification, take#4 Tejun Heo
2011-05-29 23:12 ` [PATCH 01/17] ptrace: remove silly wait_trap variable from ptrace_attach() Tejun Heo
2011-06-01 18:47 ` Oleg Nesterov
2011-06-02 5:03 ` Tejun Heo
2011-06-02 11:39 ` [PATCH UPDATED " Tejun Heo
2011-05-29 23:12 ` [PATCH 02/17] job control: rename signal->group_stop and flags to jobctl and update them Tejun Heo
2011-05-29 23:12 ` [PATCH 03/17] ptrace: ptrace_check_attach(): rename @kill to @ignore_state and add comments Tejun Heo
2011-05-29 23:12 ` [PATCH 04/17] ptrace: relocate set_current_state(TASK_TRACED) in ptrace_stop() Tejun Heo
2011-05-29 23:12 ` [PATCH 05/17] job control: introduce JOBCTL_PENDING_MASK and task_clear_jobctl_pending() Tejun Heo
2011-05-29 23:12 ` [PATCH 06/17] job control: make task_clear_jobctl_pending() clear TRAPPING automatically Tejun Heo
2011-05-29 23:12 ` [PATCH 07/17] job control: introduce task_set_jobctl_pending() Tejun Heo
2011-05-29 23:12 ` [PATCH 08/17] ptrace: use bit_waitqueue for TRAPPING instead of wait_chldexit Tejun Heo
2011-06-02 11:41 ` [PATCH UPDATED " Tejun Heo
2011-05-29 23:12 ` [PATCH 09/17] signal: remove three noop tracehooks Tejun Heo
2011-05-29 23:12 ` [PATCH 10/17] job control: introduce JOBCTL_TRAP_STOP and use it for group stop trap Tejun Heo
2011-05-29 23:12 ` [PATCH 11/17] ptrace: implement PTRACE_SEIZE Tejun Heo
2011-06-01 19:01 ` Oleg Nesterov
2011-06-01 19:55 ` Oleg Nesterov
2011-06-02 5:13 ` Tejun Heo
2011-06-02 11:43 ` [PATCH UPDATED " Tejun Heo
2011-05-29 23:12 ` [PATCH 12/17] ptrace: implement PTRACE_INTERRUPT Tejun Heo
2011-05-29 23:12 ` [PATCH 13/17] ptrace: add siginfo.si_pt_flags Tejun Heo
2011-05-29 23:12 ` [PATCH 14/17] ptrace: make group stop state visible via PTRACE_GETSIGINFO Tejun Heo
2011-05-29 23:12 ` [PATCH 15/17] ptrace: don't let PTRACE_SETSIGINFO override __SI_TRAP siginfo Tejun Heo
2011-05-29 23:12 ` [PATCH 16/17] ptrace: implement TRAP_NOTIFY and use it for group stop events Tejun Heo
2011-05-29 23:12 ` [PATCH 17/17] ptrace: implement PTRACE_LISTEN Tejun Heo
2011-06-02 17:33 ` Oleg Nesterov
2011-06-13 14:10 ` Tejun Heo
2011-06-13 20:33 ` Oleg Nesterov
2011-06-14 6:45 ` Tejun Heo
2011-05-30 15:42 ` [PATCHSET ptrace] ptrace: implement PTRACE_SEIZE/INTERRUPT and group stop notification, take#4 Oleg Nesterov
2011-06-01 5:39 ` Tejun Heo
2011-06-02 12:31 ` Tejun Heo
2011-06-02 14:51 ` Denys Vlasenko
2011-06-03 1:24 ` Tejun Heo
2011-06-03 10:25 ` Pedro Alves
2011-06-16 8:38 ` Tejun Heo
2011-06-16 9:56 ` Pedro Alves
2011-06-17 19:08 ` Oleg Nesterov
2011-06-03 11:57 ` Denys Vlasenko
2011-06-03 12:11 ` Pedro Alves
2011-06-03 14:12 ` Denys Vlasenko
2011-06-03 15:24 ` Pedro Alves
2011-06-03 15:46 ` Oleg Nesterov [this message]
2011-06-02 18:27 ` Oleg Nesterov
2011-06-02 21:09 ` Denys Vlasenko
2011-06-03 1:34 ` Tejun Heo
2011-06-03 11:37 ` Denys Vlasenko
2011-06-03 11:58 ` Denys Vlasenko
2011-06-03 15:37 ` Oleg Nesterov
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