From: "H. Peter Anvin" <hpa@zytor.com>
To: "Kasatkin, Dmitry" <dmitry.kasatkin@intel.com>
Cc: Peter Jones <pjones@redhat.com>,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [RFC 2/2] initramfs with digital signature protection
Date: Fri, 08 Feb 2013 08:50:52 -0800 [thread overview]
Message-ID: <56d80e23-a177-49dd-bb9f-eec4e7775c04@email.android.com> (raw)
In-Reply-To: <CALLzPKZ7A6NW1ztX=hBjykMHkGofvtq6g-uK=Y2B2viskE9zDQ@mail.gmail.com>
Yes, but I am talking about initramfs.
"Kasatkin, Dmitry" <dmitry.kasatkin@intel.com> wrote:
>On Fri, Feb 8, 2013 at 5:49 PM, H. Peter Anvin <hpa@zytor.com> wrote:
>> Yes, but you can't umount rootfs.
>
>But that was not a rootfs, but tmpfs/ramfs mounted to /root folder.
>
>>
>> "Kasatkin, Dmitry" <dmitry.kasatkin@intel.com> wrote:
>>
>>>On Wed, Feb 6, 2013 at 6:41 PM, H. Peter Anvin <hpa@zytor.com> wrote:
>>>> The cleanup is not a umount, it is actually a tree walk unlinking
>the
>>>contents.
>>>>
>>>
>>>Please see that umounting ramfs releases the memory.
>>>There was no forced cleanup.
>>>"cp" copied about 2GB of content.
>>>After umounting we got 2GB back to free RAM...
>>>
>>>kds@kds:~$ sudo mount -t ramfs testramfs /test
>>>kds@kds:~$ sudo cp -r /usr/ /test
>>>kds@kds:~$ du -sm /test
>>>2154 /test
>>>kds@kds:~$ free
>>> total used free shared
>>>buffers cached
>>>Mem: 8058600 7855780 202820 0 24768
>>>4819136
>>>-/+ buffers/cache: 3011876 5046724
>>>Swap: 0 0 0
>>>kds@kds:~$ sudo umount /test
>>>kds@kds:~$ free
>>> total used free shared
>>>buffers cached
>>>Mem: 8058600 5644864 2413736 0 25268
>>>2623956
>>>-/+ buffers/cache: 2995640 5062960
>>>Swap: 0 0 0
>>>
>>>The same happens also with tmpfs.
>>>
>>>- Dmitry
>>>
>>>> "Kasatkin, Dmitry" <dmitry.kasatkin@intel.com> wrote:
>>>>
>>>>>On Wed, Feb 6, 2013 at 7:04 AM, H. Peter Anvin <hpa@zytor.com>
>wrote:
>>>>>> On 02/05/2013 02:09 PM, Kasatkin, Dmitry wrote:
>>>>>>>
>>>>>>>
>>>>>>> It should not be like that. Actually when pre-init exits,
>cleanup
>>>>>code
>>>>>>> umount tmpfs, which in turn cleanups the RAM.
>>>>>>>
>>>>>>
>>>>>> It doesn't quite... the rootfs is permanent. This is also only
>one
>>>>>usage
>>>>>> mode: there are quite a few Linux systems running directly out of
>>>>>initramfs.
>>>>>>
>>>>>
>>>>>rootfs is not permanent when it is ramfs. It is cleaned up on
>switch
>>>>>root.
>>>>>It is easy to find out that it is empty by mounting : mount -t
>ramfs
>>>>>rootfs /mnt/
>>>>>
>>>>>In the case of running from normal storage, of course, there is
>>>>>ridicules remove the content.
>>>>>
>>>>>- Dmitry
>>>>>
>>>>>
>>>>>> -hpa
>>>>>>
>>>>>>
>>>>>> --
>>>>>> H. Peter Anvin, Intel Open Source Technology Center
>>>>>> I work for Intel. I don't speak on their behalf.
>>>>>>
>>>>
>>>> --
>>>> Sent from my mobile phone. Please excuse brevity and lack of
>>>formatting.
>>
>> --
>> Sent from my mobile phone. Please excuse brevity and lack of
>formatting.
--
Sent from my mobile phone. Please excuse brevity and lack of formatting.
next prev parent reply other threads:[~2013-02-08 16:51 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-05 12:34 [RFC 0/2] initramfs with digital signature protection Dmitry Kasatkin
2013-02-05 12:34 ` [RFC 1/2] export unpack_to_rootfs Dmitry Kasatkin
2013-02-05 16:48 ` Peter Jones
2013-02-05 17:16 ` Kasatkin, Dmitry
2013-02-08 8:30 ` Kasatkin, Dmitry
2013-02-05 12:34 ` [RFC 2/2] initramfs with digital signature protection Dmitry Kasatkin
2013-02-05 18:03 ` Peter Jones
2013-02-05 20:08 ` Mimi Zohar
2013-02-05 22:03 ` Kasatkin, Dmitry
2013-02-05 18:19 ` Matthew Garrett
2013-02-05 18:30 ` Matthew Garrett
2013-02-05 18:34 ` Vivek Goyal
2013-02-05 21:55 ` Kasatkin, Dmitry
2013-04-05 13:50 ` Vivek Goyal
2013-04-08 19:43 ` Mimi Zohar
2013-04-08 20:09 ` Vivek Goyal
2013-04-08 20:17 ` Josh Boyer
2013-04-09 14:38 ` Vivek Goyal
2013-04-10 3:07 ` Mimi Zohar
2013-04-10 19:42 ` Vivek Goyal
2013-04-10 21:05 ` Mimi Zohar
2013-04-11 8:08 ` Dmitry Kasatkin
2013-04-11 14:52 ` Vivek Goyal
2013-04-12 11:54 ` Mimi Zohar
[not found] ` <CACE9dm-GZpjco8u6jNxLQpYA8LYSeoVjsyyRXVwxXHzjO-LvGw@mail.gmail.com>
2013-04-11 14:55 ` Vivek Goyal
2013-04-11 18:42 ` Dmitry Kasatkin
2013-04-11 21:13 ` Vivek Goyal
2013-04-12 12:03 ` Mimi Zohar
2013-02-05 20:36 ` Peter Jones
2013-02-05 22:09 ` Kasatkin, Dmitry
2013-02-06 5:04 ` H. Peter Anvin
2013-02-06 8:01 ` Kasatkin, Dmitry
2013-02-06 16:41 ` H. Peter Anvin
2013-02-08 9:16 ` Kasatkin, Dmitry
2013-02-08 15:49 ` H. Peter Anvin
2013-02-08 16:24 ` Kasatkin, Dmitry
2013-02-08 16:50 ` H. Peter Anvin [this message]
2013-02-07 17:05 ` Vivek Goyal
2013-02-08 8:34 ` Kasatkin, Dmitry
2013-02-08 13:27 ` Kasatkin, Dmitry
2013-02-11 21:59 ` Vivek Goyal
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