Re: [PATCH v4 3/3] LSM: Add context interface for proc attrs

[Casey Schaufler]

On 6/24/2016 12:15 PM, Paul Moore wrote:
> On Thu, Jun 23, 2016 at 5:11 PM, Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
>> Subject: [PATCH v4 3/3] LSM: Add context interface for proc attrs
>>
>> The /proc/.../attr/current interface is used by all three
>> Linux security modules (SELinux, Smack and AppArmor) to
>> report and modify the process security attribute. This is
>> all fine when there is exactly one of these modules active
>> and the userspace code knows which it module it is.
>> It would require a major change to the "current" interface
>> to provide information about more than one set of process
>> security attributes. Instead, a "context" attribute is
>> added, which identifies the security module that the
>> information applies to. The format is:
>>
>>         lsmname='context-value'
>>
>> When multiple concurrent modules are supported the
>> /proc/.../attr/context interface will include the data
>> for all of the active modules.
>>
>>         lsmname1='context-value1'lsmname2='context-value2'
>>
>> The module specific subdirectories under attr contain context
>> entries that report the information for that specific module
>> in the same format.
> I think a delimiter between the different LSMs would be a good idea.
> A comma seems like a safe choice at the moment.

It's unnecessary and makes for more complicated code in
both directions, but everyone seems wedded to a delimiter.
I'll propose a v5 with a delimiter.

>