linux-modules.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jessica Yu <jeyu@kernel.org>
To: Lucas De Marchi <lucas.de.marchi@gmail.com>
Cc: Jack Rosenthal <jrosenth@chromium.org>,
	linux-modules <linux-modules@vger.kernel.org>
Subject: Re: Module compression & loadpin
Date: Thu, 8 Aug 2019 15:24:57 +0200	[thread overview]
Message-ID: <20190808132457.GB29211@linux-8ccs> (raw)
In-Reply-To: <CAKi4VA+5YBaKHoEy819MBDoCTPY9Wsu=DzXPFaibAjL91GjhzA@mail.gmail.com>

+++ Lucas De Marchi [06/08/19 15:53 -0700]:
>+Jessica
>
>On Sat, Aug 3, 2019 at 9:50 AM Jack Rosenthal <jrosenth@chromium.org> wrote:
>>
>> Has anyone looked into what it may take to support both module
>> compression and loadpin (ensures modules come from trusted filesystem)?
>>
>> From my understanding, this is not supported as kmod currently does the
>> decompression of modules, and loadpin prefers fload_module as it can
>> tell where the module came from. (https://crbug.com/777204)
>>
>> In a gist, I am thinking supporting this scenario would require the
>> module decompression to happen on the kernel side. Wondering if anyone
>> has looked into this before I go making a solution...
>
>That's my thought as well. In order to use finit_module() with
>compressed modules we need to teach the kernel how to open it. It
>should not be difficult since kernel already has the decompression
>libraries. This also gives us access to another
>compression/decompression algorithms - but would be nice to have a
>correspondent implementation for modinfo.
>
>I planned to do that some years ago, but never implemented it. Nobody
>that I know of is currently working on that. It would be a very
>welcome contribution.

Indeed, I don't know of anyone currently working on that. I do not
think it should be that difficult, since as Lucas already mentioned we
already have multiple decompression libraries in the kernel to extract
the compressed kernel image on boot (see: lib/decompress.c and
friends), so at first glance, I don't think it would be too hard to
extend this functionality to the module loader. I'd welcome a patchset :)

Thanks,

Jessica


      reply	other threads:[~2019-08-08 13:25 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20190731222209.GA101140@chromium.org>
2019-08-02 18:32 ` Module compression & loadpin Jack Rosenthal
2019-08-06 22:53   ` Lucas De Marchi
2019-08-08 13:24     ` Jessica Yu [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190808132457.GB29211@linux-8ccs \
    --to=jeyu@kernel.org \
    --cc=jrosenth@chromium.org \
    --cc=linux-modules@vger.kernel.org \
    --cc=lucas.de.marchi@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).