From: Oleg Nesterov <oleg@redhat.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-kernel@vger.kernel.org, Ben Segall <bsegall@google.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>, Mel Gorman <mgorman@suse.de>,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
Vincent Guittot <vincent.guittot@linaro.org>
Subject: Re: [PATCH v2] ptrace: fix ptrace vs tasklist_lock race on PREEMPT_RT.
Date: Tue, 5 Apr 2022 10:34:45 +0200 [thread overview]
Message-ID: <20220405083445.GA31401@redhat.com> (raw)
In-Reply-To: <20220404161339.GA21531@redhat.com>
On 04/04, Oleg Nesterov wrote:
>
> Cough. Somehow I can hardly understand v2. For example, if we fix
> wait_task_inactive() correctly, then why ptrace_freeze_traced()
> should take saved_state into account? And how can unfreeze_traced
> hit saved_state == __TASK_TRACED ?
OK, somehow I forgot that ptrace_freeze_traced() is called before
wait_task_inactive(), so it does need to check/change saved_state.
But still, ptrace_unfreeze_traced() can't see task->saved_state ==
__TASK_TRACED, right ?
Oleg.
next prev parent reply other threads:[~2022-04-05 11:07 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-02 21:04 [PATCH] ptrace: fix ptrace vs tasklist_lock race on PREEMPT_RT Sebastian Andrzej Siewior
2022-03-14 9:27 ` Sebastian Andrzej Siewior
2022-03-14 18:54 ` Oleg Nesterov
2022-03-15 8:31 ` Sebastian Andrzej Siewior
2022-03-15 14:29 ` Oleg Nesterov
2022-03-16 8:23 ` Sebastian Andrzej Siewior
2022-03-31 14:25 ` [PATCH v2] " Sebastian Andrzej Siewior
2022-04-04 16:13 ` Oleg Nesterov
2022-04-05 8:34 ` Oleg Nesterov [this message]
2022-04-05 10:10 ` Peter Zijlstra
2022-04-05 10:29 ` Oleg Nesterov
2022-04-05 11:28 ` Peter Zijlstra
2022-04-07 12:13 ` Peter Zijlstra
2022-04-07 17:51 ` Eric W. Biederman
2022-04-07 22:50 ` Eric W. Biederman
2022-04-08 9:09 ` Peter Zijlstra
2022-04-08 19:40 ` Eric W. Biederman
2022-04-08 20:06 ` Peter Zijlstra
2022-04-11 11:35 ` Peter Zijlstra
2022-04-11 13:44 ` Eric W. Biederman
2022-04-11 17:07 ` Peter Zijlstra
2022-04-12 11:59 ` Peter Zijlstra
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