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From: Oleg Nesterov <oleg@redhat.com>
To: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"keescook@chromium.org" <keescook@chromium.org>,
	"kosaki.motohiro@jp.fujitsu.com" <kosaki.motohiro@jp.fujitsu.com>,
	"matthltc@us.ibm.com" <matthltc@us.ibm.com>,
	"tj@kernel.org" <tj@kernel.org>,
	Pavel Emelianov <xemul@parallels.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: + c-r-prctl-add-ability-to-set-new-mm_struct-exe_file-update-after-mm- num_exe_file_vmas-removal.patch added to -mm tree
Date: Thu, 19 Apr 2012 23:51:09 +0200	[thread overview]
Message-ID: <20120419215109.GA4896@redhat.com> (raw)
In-Reply-To: <4F9087D0.60709@openvz.org>

On 04/20, Konstantin Khlebnikov wrote:
>
> Oleg Nesterov wrote:
>>
>> You misunderstood. I am not arguing with "one-shot", I do not really
>> care.
>>
>> My question is: unless I missed something "it can't be changed again"
>> is not actually true. A task does PR_SET_MM_EXE_FILE, then it forks
>> the new child. The child can do PR_SET_MM_EXE_FILE again. Is this
>> by design?
>>
>> Oleg.
>>
>
> I found more weird case: child thread (with CLONE_THREAD and without CLONE_VM)
> changes its exe_file...

No. copy_process() does:

	if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
		return ERR_PTR(-EINVAL);

	if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
		return ERR_PTR(-EINVAL);

IOW, CLONE_THREAD => CLONE_SIGHAND => CLONE_VM

Oleg.


  reply	other threads:[~2012-04-19 21:51 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20120419185221.E8ED6A055E@akpm.mtv.corp.google.com>
2012-04-19 19:20 ` + c-r-prctl-add-ability-to-set-new-mm_struct-exe_file-update-after-mm- num_exe_file_vmas-removal.patch added to -mm tree Oleg Nesterov
2012-04-19 21:00   ` Cyrill Gorcunov
2012-04-19 21:12     ` Oleg Nesterov
2012-04-19 21:32       ` Cyrill Gorcunov
2012-04-19 22:08         ` Konstantin Khlebnikov
2012-04-19 22:16           ` Cyrill Gorcunov
2012-04-19 22:29           ` Oleg Nesterov
2012-04-19 21:46       ` Konstantin Khlebnikov
2012-04-19 21:51         ` Oleg Nesterov [this message]
2012-04-19 22:02           ` Cyrill Gorcunov
2012-04-19 22:09             ` Oleg Nesterov
2012-04-19 22:28               ` Konstantin Khlebnikov
2012-04-19 22:32               ` Cyrill Gorcunov

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