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From: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
To: Kees Cook <keescook@chromium.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>,
	"H. Peter Anvin" <hpa@zytor.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Lucas De Marchi <lucas.demarchi@profusion.mobi>,
	jonathon@jonmasters.org, linux-man@vger.kernel.org
Subject: Re: [PATCH 1/4] module: add syscall to load module from fd
Date: Mon, 7 Jan 2013 02:41:27 +0100	[thread overview]
Message-ID: <CAKgNAkgG_NpVV7DSKZV2NgG2HDv+Vf=BAGjedfdBbhGBSWMfug@mail.gmail.com> (raw)
In-Reply-To: <CAGXu5jJXoYO3CzpENAZYANLzySPPjzDVO_qLonqwxUUu1Ux=sg@mail.gmail.com>

On Sun, Jan 6, 2013 at 9:24 PM, Kees Cook <keescook@chromium.org> wrote:
> On Sun, Jan 6, 2013 at 11:59 AM, Michael Kerrisk (man-pages)
> <mtk.manpages@gmail.com> wrote:
>> Hi Rusty, (and Lucas, and Kees)
>>
>> On Thu, Jan 3, 2013 at 1:12 AM, Rusty Russell <rusty@rustcorp.com.au> wrote:
>>> Michael Kerrisk <mtk.manpages@gmail.com> writes:
>>>> Hi Rusty,
>>>
>>> Hi Michael,
>>>
>>>> The description here is rather thin. Could you supply a sentence or
>>>> two for each of MODULE_INIT_IGNORE_MODVERSIONS and
>>>> MODULE_INIT_IGNORE_VERMAGIC that would be suitable for the manual
>>>> page?
>>>>
>>>> Thanks,
>>>
>>> There are one or two safety checks built into a module, which are
>>> checked to match the kernel on module load.  The first is a "vermagic"
>>> string containing the kernel version number and prominent features (such
>>> as CPU type).  If the module was built with CONFIG_MODVERSIONS set, a
>>> version hash is recorded for each symbol the module uses based on the
>>> types it refers to: in this case, the kernel version number within the
>>> "vermagic" string is ignored, as the symbol version hashes are assumed
>>> to be sufficiently reliable.
>>>
>>> Using the MODULE_INIT_IGNORE_VERMAGIC flag indicates that the vermagic
>>> is to be ignored, and the MODULE_INIT_IGNORE_MODVERSIONS flag indicates
>>> that the version hashes are to be ignored.  If the kernel is built to
>>> permit such forced loading (ie. CONFIG_MODULE_FORCE_LOAD is set) then
>>> loading will continue, otherwise it will fail with ENOEXEC as expected
>>> for malformed modules.
>>>
>>> Hope that is more usable?
>>
>> Yes, that helps. I did some reworking of that text. Hopefully, I did
>> not introduce any errors.
>>
>> Below is the text that is proposed to document finit_module() in the
>> man pages. I'd appreciate any review (Kees, Lucas, Rusty?)
>
> Looks good to me!
>
> Reviewed-by: Kees Cook <keescook@chromium.org>

Thanks Kees!



-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Author of "The Linux Programming Interface"; http://man7.org/tlpi/

  reply	other threads:[~2013-01-07  1:41 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-20 22:14 [PATCH 1/4] module: add syscall to load module from fd Kees Cook
2012-09-20 22:14 ` [PATCH 2/4] security: introduce kernel_module_from_file hook Kees Cook
2012-09-21 12:42   ` Mimi Zohar
2012-09-20 22:14 ` [PATCH 3/4] ARM: add finit_module syscall to ARM Kees Cook
2012-09-21 13:15   ` Arnd Bergmann
2012-09-21 14:59     ` Russell King
2012-09-21 15:43       ` Kees Cook
2012-09-20 22:15 ` [PATCH 4/4] add finit_module syscall to asm-generic Kees Cook
2012-09-21  2:22 ` [PATCH 1/4] module: add syscall to load module from fd James Morris
2012-09-21  3:07   ` Kees Cook
2012-09-21  3:09   ` Mimi Zohar
2012-09-21 17:56   ` John Johansen
2012-10-03 22:40 ` Kees Cook
2012-10-04  5:39   ` Rusty Russell
2012-10-04 12:50     ` Mimi Zohar
2012-10-05  3:50       ` Rusty Russell
2012-10-05  7:12         ` Kees Cook
2012-10-04 20:28     ` Kees Cook
2012-10-09 21:54 ` Michael Kerrisk
2012-10-09 21:58   ` H. Peter Anvin
2012-10-09 22:03     ` Michael Kerrisk (man-pages)
2012-10-09 22:09       ` H. Peter Anvin
     [not found]         ` <CAKgNAkjfkbYOQocuGRAKU=0P2CQCvmedhRMJZPnkUMnnxSOsqg@mail.gmail.com>
2012-10-10  5:54           ` Michael Kerrisk (man-pages)
2012-10-11 22:16         ` Rusty Russell
2012-10-12  5:16           ` Michael Kerrisk (man-pages)
2012-10-18  3:12             ` Rusty Russell
2012-10-18  5:39               ` Lucas De Marchi
2012-10-18 12:59               ` Michael Kerrisk (man-pages)
2012-10-22  7:39                 ` Rusty Russell
2012-10-23  2:37                   ` Lucas De Marchi
2012-10-23  3:40                     ` Kees Cook
2012-10-23  4:08                       ` Lucas De Marchi
2012-10-23 15:42                         ` Kees Cook
2012-10-23 15:45                           ` H. Peter Anvin
2012-10-23 16:25                           ` Lucas De Marchi
2012-10-24  3:06                             ` Rusty Russell
2012-10-23  7:38                   ` Michael Kerrisk (man-pages)
2012-10-30 21:57                   ` Kees Cook
2012-11-01  1:03                     ` Rusty Russell
2012-12-21  0:01                   ` Michael Kerrisk
2013-01-03  0:12                     ` Rusty Russell
2013-01-06 18:59                       ` Michael Kerrisk (man-pages)
2013-01-06 20:24                         ` Kees Cook
2013-01-07  1:41                           ` Michael Kerrisk (man-pages) [this message]
2013-01-09 17:29                         ` Lucas De Marchi
2013-01-10  0:55                           ` Michael Kerrisk (man-pages)
2012-10-18  4:24           ` H. Peter Anvin
2012-10-18  8:05             ` Michael Kerrisk (man-pages)
2012-10-18 14:26               ` H. Peter Anvin
2012-10-18 15:28                 ` Kees Cook
2012-10-18 15:30                   ` H. Peter Anvin
2012-10-19  2:23                 ` Rusty Russell
2012-10-19  2:54                   ` H. Peter Anvin
2012-10-19 10:46                     ` Alon Ziv
2012-10-20  4:05                     ` Rusty Russell
  -- strict thread matches above, loose matches on Subject: below --
2012-10-04 20:22 [PATCH v5] " Kees Cook
2012-10-04 20:22 ` [PATCH 1/4] " Kees Cook

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