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Subject: Re: [RFC PATCH v7 07/16] ipe: add auditing support
To:     Deven Bowers <deven.desai@linux.microsoft.com>, corbet@lwn.net,
        axboe@kernel.dk, agk@redhat.com, snitzer@redhat.com,
        ebiggers@kernel.org, tytso@mit.edu, paul@paul-moore.com,
        eparis@redhat.com, jmorris@namei.org, serge@hallyn.com
Cc:     jannh@google.com, dm-devel@redhat.com, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-fscrypt@vger.kernel.org, linux-audit@redhat.com,
        linux-security-module@vger.kernel.org
References: <1634151995-16266-1-git-send-email-deven.desai@linux.microsoft.com>
 <1634151995-16266-8-git-send-email-deven.desai@linux.microsoft.com>
 <9c1eec3b-8bb0-9e3e-d6e5-18c670ac2b03@infradead.org>
 <7bd474ae-3dbe-4351-fa10-ee68e5c7267c@linux.microsoft.com>
From:   Randy Dunlap <rdunlap@infradead.org>
Message-ID: <e4bc834b-5483-604d-7fa1-e5eafdd5ebf5@infradead.org>
Date:   Fri, 15 Oct 2021 12:50:05 -0700
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On 10/15/21 12:25 PM, Deven Bowers wrote:
> On 10/13/2021 3:54 PM, Randy Dunlap wrote:
>> Hi,
>>
>> On 10/13/21 12:06 PM, deven.desai@linux.microsoft.com wrote:
>>> diff --git a/security/ipe/Kconfig b/security/ipe/Kconfig
>>> index c4503083e92d..ef556b66e674 100644
>>> --- a/security/ipe/Kconfig
>>> +++ b/security/ipe/Kconfig
>>> @@ -17,3 +17,55 @@ menuconfig SECURITY_IPE
>>>         requirements on the fly.
>>>           If unsure, answer N.
>>> +
>>> +if SECURITY_IPE
>>> +
>>> +choice
>>> +    prompt "Hash algorithm used in auditing policies"
>>> +    default IPE_AUDIT_HASH_SHA1
>>> +    depends on AUDIT
>>> +    help
>>> +        Specify the hash algorithm used when auditing policies.
>>> +        The hash is used to uniquely identify a policy from other
>>> +        policies on the system.
>>> +
>>> +        If unsure, leave default.
>>> +
>>> +    config IPE_AUDIT_HASH_SHA1
>>> +        bool "sha1"
>>> +        depends on CRYPTO_SHA1
>>> +        help
>>> +            Use the SHA128 algorithm to hash policies
>>> +            in the audit records.
>>> +
>>> +    config IPE_AUDIT_HASH_SHA256
>>> +        bool "sha256"
>>> +        depends on CRYPTO_SHA256
>>> +        help
>>> +            Use the SHA256 algorithm to hash policies
>>> +            in the audit records.
>>> +
>>> +    config IPE_AUDIT_HASH_SHA384
>>> +        bool "sha384"
>>> +        depends on CRYPTO_SHA512
>>> +        help
>>> +            Use the SHA384 algorithm to hash policies
>>> +            in the audit records
>>> +
>>> +    config IPE_AUDIT_HASH_SHA512
>>> +        bool "sha512"
>>> +        depends on CRYPTO_SHA512
>>> +        help
>>> +            Use the SHA512 algorithm to hash policies
>>> +            in the audit records
>>> +endchoice
>>> +
>>> +config IPE_AUDIT_HASH_ALG
>>> +    string
>>> +    depends on AUDIT
>>> +    default "sha1" if IPE_AUDIT_HASH_SHA1
>>> +    default "sha256" if IPE_AUDIT_HASH_SHA256
>>> +    default "sha384" if IPE_AUDIT_HASH_SHA384
>>> +    default "sha512" if IPE_AUDIT_HASH_SHA512
>>> +
>>> +endif
>>
>> Please follow coding-style for Kconfig files:
>>
>> (from Documentation/process/coding-style.rst, section 10):
>>
>> For all of the Kconfig* configuration files throughout the source tree,
>> the indentation is somewhat different.  Lines under a ``config`` definition
>> are indented with one tab, while help text is indented an additional two
>> spaces.
>>
> Oof. That's embarrassing. Sorry, I'll fix this for v8.
> 
> While I'm at it, is the help text required for choice configs?
> checkpatch --strict complains with a warning without them, but
> I see other places in the tree where help text is omitted for
> these configs attached to a choice.

Does checkpatch complain about what you have above
or did you add that help text to keep it from complaining?


> Documentation/process/* doesn't seem to have any guidance, nor
> Documentation/kbuild/* on whether it is safe to ignore that
> checkpatch warning.

Yeah, I don't think that we have any good guidance on that.

I would say that if the choice prompt provides good/adequate
help info, then each 'config' inside the choice block does not
need help text. OTOH, if the choice prompt has little/no help
info, then each 'config' under it should have some useful info.

I only looked in arch/x86/Kconfig, init/Kconfig, and lib/Kconfig.debug,
but you can see either help text method being used in those.

And then if the help text is adequate in either one of those
methods, I would just ignore the checkpatch complaints.
It's just a guidance tool.

HTH.

-- 
~Randy