Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Paul Moore <paul@paul-moore.com>
To:     Greg KH <gregkh@linuxfoundation.org>
CC:     =?UTF-8?B?TWlja2HDq2wgU2FsYcO8bg==?= <mic@digikod.net>,
        Casey Schaufler <casey@schaufler-ca.com>,
        <casey.schaufler@intel.com>,
        <linux-security-module@vger.kernel.org>, <jmorris@namei.org>,
        <keescook@chromium.org>, <john.johansen@canonical.com>,
        <penguin-kernel@i-love.sakura.ne.jp>,
        <stephen.smalley.work@gmail.com>, <linux-kernel@vger.kernel.org>,
        <linux-api@vger.kernel.org>
Date:   Mon, 28 Nov 2022 07:49:11 -0500
Message-ID: <184be48c558.28e3.85c95baa4474aabc7814e68940a78392@paul-moore.com>
In-Reply-To: <Y4Rok2iAOekw/tSJ@kroah.com>
References: <20221123201552.7865-1-casey@schaufler-ca.com>
 <20221123201552.7865-2-casey@schaufler-ca.com>
 <Y38D1s3uQ6zNORei@kroah.com>
 <463cb747-5bac-9e8e-b78e-1ff6a1b29142@digikod.net>
 <CAHC9VhR9h1GF6VGovp1+UB-vt+QNofjmecPwLqE3OviKQHRMcg@mail.gmail.com>
 <Y4Rok2iAOekw/tSJ@kroah.com>
User-Agent: AquaMail/1.40.1 (build: 104001224)
Subject: Re: [PATCH v3 1/9] LSM: Identify modules by more than name
MIME-Version: 1.0
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On November 28, 2022 2:51:55 AM Greg KH <gregkh@linuxfoundation.org> wrote:

> On Sun, Nov 27, 2022 at 10:48:53PM -0500, Paul Moore wrote:
>> On Fri, Nov 25, 2022 at 11:19 AM Micka=C3=ABl Sala=C3=BCn <mic@digikod.n=
et> wrote:
>>> On 24/11/2022 06:40, Greg KH wrote:
>>>> On Wed, Nov 23, 2022 at 12:15:44PM -0800, Casey Schaufler wrote:
>>>>> Create a struct lsm_id to contain identifying information
>>>>> about Linux Security Modules (LSMs). At inception this contains
>>>>> the name of the module and an identifier associated with the
>>>>> security module. Change the security_add_hooks() interface to
>>>>> use this structure. Change the individual modules to maintain
>>>>> their own struct lsm_id and pass it to security_add_hooks().
>>>>>
>>>>> The values are for LSM identifiers are defined in a new UAPI
>>>>> header file linux/lsm.h. Each existing LSM has been updated to
>>>>> include it's LSMID in the lsm_id.
>>>>>
>>>>> The LSM ID values are sequential, with the oldest module
>>>>> LSM_ID_CAPABILITY being the lowest value and the existing modules
>>>>> numbered in the order they were included in the main line kernel.
>>>>> This is an arbitrary convention for assigning the values, but
>>>>> none better presents itself. The value 0 is defined as being invalid.
>>>>> The values 1-99 are reserved for any special case uses which may
>>>>> arise in the future.
>>>>
>>>> What would be a "special case" that deserves a lower number?
>>>
>>> I don't see any meaningful use case for these reserved numbers either.
>>> If there are some, let's put them now, otherwise we should start with 1=
.
>>> Is it inspired by an existing UAPI?
>>> Reserving 0 as invalid is good though.
>>
>> I haven't finished reviewing this latest patchset, but I wanted to
>> comment on this quickly while I had a moment in front of a keyboard
>> ... I did explain my desire and reasoning for this in a previous
>> revision of this patchset and I still believe the
>> reserved-for-potential-future-use to be a valid reason so I'm going to
>> ask for this to remain.
>
> Then that reasoning and explaination needs to be here in the changelog
> so that we understand and have a chance to agree/disagree with that.
> Otherwise we, and everyone else, are left to just be confused.
>
> thanks,
>
> greg k-h

The patch author should have done that considering I made my comments on th=
e last revision.

--
paul-moore.com