Re: crypto: hang in crypto_larval_lookup

[Harald Freudenberger <freude@linux.vnet.ibm.com>]

On 02/26/2017 05:22 AM, Herbert Xu wrote:
> On Sat, Feb 25, 2017 at 04:20:22PM -0300, Marcelo Cerri wrote:
>> Yeah, I agree. This should work as long as the module aliases are
>> correct, which is enough.
>>
>> Other templates will not trigger the same error since they don't have to
>> try more than one underlying algorithm. But I think this is still
>> desirable for the remaining templates to avoid a long chain of unused
>> fallbacks as in the example I gave in my previous email.
>>
>> Probably a helper function to return the correct mask might be useful
>> for readability and to avoid duplicate code.
> You're right.  Here is a patch to add a helper for this.
> Thanks!
>
> ---8<---
> Subject: crypto: api - Add crypto_requires_off helper
>
> This patch adds crypto_requires_off which is an extension of
> crypto_requires_sync for similar bits such as NEED_FALLBACK.
>
> Suggested-by: Marcelo Cerri <marcelo.cerri@canonical.com>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
>
> diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h
> index ebe4ded..436c4c2 100644
> --- a/include/crypto/algapi.h
> +++ b/include/crypto/algapi.h
> @@ -360,13 +360,18 @@ static inline struct crypto_alg *crypto_get_attr_alg(struct rtattr **tb,
>  	return crypto_attr_alg(tb[1], type, mask);
>  }
>
> +static inline int crypto_requires_off(u32 type, u32 mask, u32 off)
> +{
> +	return (type ^ off) & mask & off;
> +}
> +
>  /*
>   * Returns CRYPTO_ALG_ASYNC if type/mask requires the use of sync algorithms.
>   * Otherwise returns zero.
>   */
>  static inline int crypto_requires_sync(u32 type, u32 mask)
>  {
> -	return (type ^ CRYPTO_ALG_ASYNC) & mask & CRYPTO_ALG_ASYNC;
> +	return crypto_requires_off(type, mask, CRYPTO_ALG_ASYNC);
>  }
>
>  noinline unsigned long __crypto_memneq(const void *a, const void *b, size_t size);
applied the xts.c create patch v2 and the helper patch, built and installed.
Now the aes_s390 module loads perfect without any hang, no complains
in syslog and /proc/crypto shows that all selftests for the algs in the module
passed successful.

Thanks all for your help :-)

regards, Harald Freudenberger