Re: [PATCH v3 1/9] LSM: Identify modules by more than name

[Paul Moore]

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

> On Sun, Nov 27, 2022 at 10:48:53PM -0500, Paul Moore wrote:
>> On Fri, Nov 25, 2022 at 11:19 AM Mickaël Salaün <mic@xxxxxxxxxxx> 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 the last revision.

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