Linux-Modules Archive on lore.kernel.org
 help / color / Atom feed
From: Matthias Maennich <maennich@google.com>
To: Saravana Kannan <saravanak@google.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
	maco@android.com, Android Kernel Team <kernel-team@android.com>,
	arnd@arndb.de, geert@linux-m68k.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	hpa@zytor.com, jeyu@kernel.org,
	"Joel Fernandes (Google)" <joel@joelfernandes.org>,
	kstewart@linuxfoundation.org, linux-arch@vger.kernel.org,
	linux-kbuild@vger.kernel.org, linux-m68k@lists.linux-m68k.org,
	linux-modules@vger.kernel.org, linux-scsi@vger.kernel.org,
	linux-usb@vger.kernel.org, lucas.de.marchi@gmail.com,
	maco@google.com, michal.lkml@markovi.net, mingo@redhat.com,
	oneukum@suse.com, pombredanne@nexb.com, sam@ravnborg.org,
	Sandeep Patil <sspatil@google.com>,
	stern@rowland.harvard.edu, tglx@linutronix.de,
	usb-storage@lists.one-eyed-alien.net, x86@kernel.org,
	yamada.masahiro@socionext.com,
	Andrew Morton <akpm@linux-foundation.org>,
	Johannes Weiner <hannes@cmpxchg.org>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>,
	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
	David Howells <dhowells@redhat.com>,
	Patrick Bellasi <patrick.bellasi@arm.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Adrian Reber <adrian@lisas.de>,
	Richard Guy Briggs <rgb@redhat.com>
Subject: Re: [PATCH v2 05/10] module: add config option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
Date: Wed, 14 Aug 2019 13:54:27 +0100
Message-ID: <20190814125427.GA72826@google.com> (raw)
In-Reply-To: <CAGETcx_LQDdnaU+3JVGw+6=DJ8tRoQ00+3rD2gOiHHkWomt8jg@mail.gmail.com>

On Tue, Aug 13, 2019 at 01:15:44PM -0700, Saravana Kannan wrote:
>On Tue, Aug 13, 2019 at 5:19 AM 'Matthias Maennich' via kernel-team
><kernel-team@android.com> wrote:
>>
>> If MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS is enabled (default=n), the
>> requirement for modules to import all namespaces that are used by
>> the module is relaxed.
>>
>> Enabling this option effectively allows (invalid) modules to be loaded
>> while only a warning is emitted.
>>
>> Disabling this option keeps the enforcement at module loading time and
>> loading is denied if the module's imports are not satisfactory.
>>
>> Reviewed-by: Martijn Coenen <maco@android.com>
>> Signed-off-by: Matthias Maennich <maennich@google.com>
>> ---
>>  init/Kconfig    | 14 ++++++++++++++
>>  kernel/module.c | 11 +++++++++--
>>  2 files changed, 23 insertions(+), 2 deletions(-)
>>
>> diff --git a/init/Kconfig b/init/Kconfig
>> index bd7d650d4a99..b3373334cdf1 100644
>> --- a/init/Kconfig
>> +++ b/init/Kconfig
>> @@ -2119,6 +2119,20 @@ config MODULE_COMPRESS_XZ
>>
>>  endchoice
>>
>> +config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
>> +       bool "Allow loading of modules with missing namespace imports"
>> +       default n
>> +       help
>> +         Symbols exported with EXPORT_SYMBOL_NS*() are considered exported in
>> +         a namespace. A module that makes use of a symbol exported with such a
>> +         namespace is required to import the namespace via MODULE_IMPORT_NS().
>> +         This option relaxes this requirement when loading a module.
>
>> While
>> +         technically there is no reason to enforce correct namespace imports,
>> +         it creates consistency between symbols defining namespaces and users
>> +         importing namespaces they make use of.
>
>I'm confused by this sentence. It sounds like it's the opposite of
>what the config is doing? Can you please reword it for clarify?

How about:

  Symbols exported with EXPORT_SYMBOL_NS*() are considered exported in
  a namespace. A module that makes use of a symbol exported with such a
  namespace is required to import the namespace via MODULE_IMPORT_NS().
  There is no technical reason to enforce correct namespace imports,
  but it creates consistency between symbols defining namespaces and
  users importing namespaces they make use of. This option relaxes this
  requirement and lifts the enforcement when loading a module.

-- 
Cheers,
Matthias

  reply index

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20180716122125.175792-1-maco@android.com>
     [not found] ` <20180716122125.175792-3-maco@android.com>
     [not found]   ` <CAB0TPYEOVHcFGFLTjVvk7R0VSgSnXZRi1PjSYXONJSjqd4NewQ@mail.gmail.com>
     [not found]     ` <20180725155507.umb5oatduquxwlmt@linux-8ccs>
2018-07-25 16:48       ` [PATCH 2/6] module: add support for symbol namespaces Lucas De Marchi
2018-07-26  7:44         ` Martijn Coenen
2019-08-13 12:16 ` [PATCH v2 0/10] Symbol namespaces - RFC Matthias Maennich
2019-08-13 12:16   ` [PATCH v2 01/10] module: support reading multiple values per modinfo tag Matthias Maennich
2019-08-13 12:40     ` Greg KH
2019-08-13 12:16   ` [PATCH v2 02/10] export: explicitly align struct kernel_symbol Matthias Maennich
2019-08-13 12:41     ` Greg KH
2019-08-13 12:17   ` [PATCH v2 03/10] module: add support for symbol namespaces Matthias Maennich
2019-08-13 15:26     ` Greg KH
2019-08-13 12:17   ` [PATCH v2 04/10] modpost: " Matthias Maennich
2019-08-13 15:27     ` Greg KH
2019-08-13 12:17   ` [PATCH v2 05/10] module: add config option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS Matthias Maennich
2019-08-13 18:17     ` Greg KH
2019-08-13 20:15     ` Saravana Kannan
2019-08-14 12:54       ` Matthias Maennich [this message]
2019-08-14 17:34         ` Saravana Kannan
2019-08-13 12:17   ` [PATCH v2 06/10] export: allow definition default namespaces in Makefiles or sources Matthias Maennich
2019-08-13 18:16     ` Greg KH
2019-08-13 18:16     ` Greg KH
2019-08-13 12:17   ` [PATCH v2 07/10] modpost: add support for generating namespace dependencies Matthias Maennich
2019-08-13 18:21     ` Greg KH
2019-08-13 12:17   ` [PATCH v2 08/10] scripts: Coccinelle script for " Matthias Maennich
2019-08-13 12:31     ` Julia Lawall
2019-08-13 12:44     ` Greg KH
2019-08-14  6:36     ` [Cocci] " Himanshu Jha
2019-08-14  8:03       ` Matthias Maennich
2019-08-14 12:00     ` [v2 " Markus Elfring
2019-08-15 13:50     ` Markus Elfring
2019-08-13 12:17   ` [PATCH v2 09/10] usb-storage: remove single-use define for debugging Matthias Maennich
2019-08-13 12:42     ` Greg KH
2019-08-13 13:12       ` Greg KH
2019-08-13 12:17   ` [PATCH v2 10/10] RFC: usb-storage: export symbols in USB_STORAGE namespace Matthias Maennich
2019-08-13 12:45     ` Greg KH
2019-08-13 12:47     ` Greg KH
2019-08-13 15:02       ` Matthias Maennich

Reply instructions:

You may reply publically 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=20190814125427.GA72826@google.com \
    --to=maennich@google.com \
    --cc=adrian@lisas.de \
    --cc=akpm@linux-foundation.org \
    --cc=arnd@arndb.de \
    --cc=dan.j.williams@intel.com \
    --cc=dhowells@redhat.com \
    --cc=geert@linux-m68k.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=hannes@cmpxchg.org \
    --cc=hpa@zytor.com \
    --cc=jeyu@kernel.org \
    --cc=joel@joelfernandes.org \
    --cc=kernel-team@android.com \
    --cc=kstewart@linuxfoundation.org \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-m68k@lists.linux-m68k.org \
    --cc=linux-modules@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=lucas.de.marchi@gmail.com \
    --cc=maco@android.com \
    --cc=maco@google.com \
    --cc=mchehab+samsung@kernel.org \
    --cc=michal.lkml@markovi.net \
    --cc=mingo@redhat.com \
    --cc=oneukum@suse.com \
    --cc=patrick.bellasi@arm.com \
    --cc=peterz@infradead.org \
    --cc=pombredanne@nexb.com \
    --cc=rgb@redhat.com \
    --cc=sam@ravnborg.org \
    --cc=saravanak@google.com \
    --cc=sspatil@google.com \
    --cc=stern@rowland.harvard.edu \
    --cc=tglx@linutronix.de \
    --cc=usb-storage@lists.one-eyed-alien.net \
    --cc=x86@kernel.org \
    --cc=yamada.masahiro@socionext.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

Linux-Modules Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-modules/0 linux-modules/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-modules linux-modules/ https://lore.kernel.org/linux-modules \
		linux-modules@vger.kernel.org linux-modules@archiver.kernel.org
	public-inbox-index linux-modules


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-modules


AGPL code for this site: git clone https://public-inbox.org/ public-inbox