linux-kernel - Re: [PATCH 5/5] crypto: ahash.c: Require export/import in ahash

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Date:   Fri, 19 Jan 2018 11:08:18 +0100
From:   Marek Vasut <marex@...x.de>
To:     Kamil Konieczny <k.konieczny@...tner.samsung.com>,
        linux-crypto@...r.kernel.org
Cc:     "David S. Miller" <davem@...emloft.net>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Sonic Zhang <sonic.zhang@...log.com>,
        Fabio Estevam <fabio.estevam@...escale.com>,
        Shawn Guo <shawn.guo@...aro.org>,
        Tom Lendacky <thomas.lendacky@....com>,
        Jan Engelhardt <jengelh@...i.de>,
        Arvind Yadav <arvind.yadav.cs@...il.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Joakim Bech <joakim.bech@...aro.org>,
        linux-kernel@...r.kernel.org,
        Herbert Xu <herbert@...dor.apana.org.au>
Subject: Re: [PATCH 5/5] crypto: ahash.c: Require export/import in ahash

On 01/19/2018 10:53 AM, Kamil Konieczny wrote:
> On 18.01.2018 22:31, Marek Vasut wrote:
>> On 01/18/2018 07:34 PM, Kamil Konieczny wrote:
>>> Export and import are mandatory in async hash. As drivers were
>>> rewritten, drop empty wrappers and correct init of ahash transformation.
>>
>> Are you moving checks from the core subsystem to drivers ? This looks
>> really nonsensical and the commit message doesn't explain the rationale
>> for that at all.
> 
> I am removing checks from core. Export and import were optional in beginnig
> of crypto framework, but as time goes on they become mandatory.

Seems like if the driver doesn't implement those, the core can easily
detect that and perform the necessary action. Moving the checks out of
core seems like the wrong thing to do, rather you should enhance the
checks in core if they're insufficient in my opinion.

>>
>>> Signed-off-by: Kamil Konieczny <k.konieczny@...tner.samsung.com>
>>> ---
>>>  crypto/ahash.c | 18 ++----------------
>>>  1 file changed, 2 insertions(+), 16 deletions(-)
>>>
>>> diff --git a/crypto/ahash.c b/crypto/ahash.c
>>> index 3a35d67de7d9..c3cce508c1d4 100644
>>> --- a/crypto/ahash.c
>>> +++ b/crypto/ahash.c
>>> @@ -434,16 +434,6 @@ static int ahash_def_finup(struct ahash_request *req)
>>>  	return ahash_def_finup_finish1(req, err);
>>>  }
>>>  
>>> -static int ahash_no_export(struct ahash_request *req, void *out)
>>> -{
>>> -	return -ENOSYS;
>>> -}
>>> -
>>> -static int ahash_no_import(struct ahash_request *req, const void *in)
>>> -{
>>> -	return -ENOSYS;
>>> -}
>>> -
>>>  static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
>>>  {
>>>  	struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
>>> @@ -451,8 +441,6 @@ static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
>>>  
>>>  	hash->setkey = ahash_nosetkey;
>>>  	hash->has_setkey = false;
>>> -	hash->export = ahash_no_export;
>>> -	hash->import = ahash_no_import;
>>>  
>>>  	if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
>>>  		return crypto_init_shash_ops_async(tfm);
>>> @@ -462,15 +450,13 @@ static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
>>>  	hash->final = alg->final;
>>>  	hash->finup = alg->finup ?: ahash_def_finup;
>>>  	hash->digest = alg->digest;
>>> +	hash->export = alg->export;
>>> +	hash->import = alg->import;
>>>  
>>>  	if (alg->setkey) {
>>>  		hash->setkey = alg->setkey;
>>>  		hash->has_setkey = true;
>>>  	}
>>> -	if (alg->export)
>>> -		hash->export = alg->export;
>>> -	if (alg->import)
>>> -		hash->import = alg->import;
>>>  
>>>  	return 0;
>>>  }
>>>
>>
>>
> 


-- 
Best regards,
Marek Vasut