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From: Peter Zijlstra <peterz@infradead.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill Tkhai <ktkhai@parallels.com>,
	linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
	Vladimir Davydov <vdavydov@parallels.com>,
	Kirill Tkhai <tkhai@yandex.ru>
Subject: Re: [PATCH RFC] sched: Revert delayed_put_task_struct() and fix use after free
Date: Thu, 16 Oct 2014 10:01:06 +0200	[thread overview]
Message-ID: <20141016080106.GD7369@worktop.fdxtended.com> (raw)
In-Reply-To: <20141015150641.GA2755@redhat.com>

On Wed, Oct 15, 2014 at 05:06:41PM +0200, Oleg Nesterov wrote:
> 
> At least the code like
> 
> 	rcu_read_lock();
> 	get_task_struct(foreign_rq->curr);
> 	rcu_read_unlock();
> 
> is certainly wrong. And _probably_ the problem should be fixed here. Perhaps
> we can add try_to_get_task_struct() which does atomic_inc_not_zero() ...

There is an rcu_read_lock() around it through task_numa_compare().

  parent reply	other threads:[~2014-10-16  8:01 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-15 12:31 [PATCH RFC] sched: Revert delayed_put_task_struct() and fix use after free Kirill Tkhai
2014-10-15 15:06 ` Oleg Nesterov
2014-10-15 19:40   ` Oleg Nesterov
2014-10-15 21:46     ` Kirill Tkhai
2014-10-15 22:02       ` Kirill Tkhai
2014-10-16  7:59       ` Peter Zijlstra
2014-10-16  8:16         ` Kirill Tkhai
2014-10-16  9:43           ` Peter Zijlstra
2014-10-16  9:50             ` Kirill Tkhai
2014-10-16  9:51               ` Kirill Tkhai
2014-10-16 10:04                 ` Kirill Tkhai
2014-10-17 21:34       ` Oleg Nesterov
2014-10-16  7:56     ` Peter Zijlstra
2014-10-16  8:01   ` Peter Zijlstra [this message]
2014-10-16 22:05     ` Oleg Nesterov
2014-10-17 21:36 ` [PATCH] sched/numa: fix unsafe get_task_struct() in task_numa_assign() Oleg Nesterov
2014-10-18  8:15   ` Kirill Tkhai
2014-10-18  8:33     ` Kirill Tkhai
2014-10-18 19:36       ` Peter Zijlstra
2014-10-18 21:18         ` Oleg Nesterov
2014-10-19  8:20         ` Kirill Tkhai
2014-10-18 20:56     ` Oleg Nesterov
2014-10-18 23:13       ` Kirill Tkhai
2014-10-19 19:24         ` Oleg Nesterov
2014-10-19 19:37           ` Oleg Nesterov
2014-10-19 19:43             ` Oleg Nesterov
2014-10-20  9:03               ` Kirill Tkhai
2014-10-20  9:13             ` Peter Zijlstra
2014-10-20 10:36               ` Kirill Tkhai
2014-10-20  9:00           ` Kirill Tkhai
2014-10-19 21:38         ` Peter Zijlstra
2014-10-20  8:56           ` Kirill Tkhai

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