Re: [PATCH] crypto: api - Do not create test larvals if manager is disabled

[Damien Le Moal <Damien.LeMoal@wdc.com>]

On 2021/11/03 0:41, Geert Uytterhoeven wrote:
>  	Hi Herbert,
> 
> On Tue, 19 Oct 2021, Herbert Xu wrote:
>> On Tue, Oct 05, 2021 at 07:33:28PM -0700, Nathan Chancellor wrote:
>>> I assume this is the diff you mean? This does not resolve the issue. My
>>> apologies if I am slow to respond, I am on vacation until the middle of
>>> next week.
>>
>> Sorry for the delay.  The kernel robot figured out the problem
>> for me.  It's the crypto_alg_tested call that causes api.c to
>> depend on algapi.c.  This call is only invoked in the case where
>> the crypto manager is turned off.  We could instead simply make
>> test larvals disappear in that case.
>>
>> ---8<---
>> The delayed boot-time testing patch created a dependency loop
>> between api.c and algapi.c because it added a crypto_alg_tested
>> call to the former when the crypto manager is disabled.
>>
>> We could instead avoid creating the test larvals if the crypto
>> manager is disabled.  This avoids the dependency loop as well
>> as saving some unnecessary work, albeit in a very unlikely case.
>>
>> Reported-by: Nathan Chancellor <nathan@kernel.org>
>> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
>> Reported-by: kernel test robot <lkp@intel.com>
>> Fixes: adad556efcdd ("crypto: api - Fix built-in testing dependency failures")
>> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
> 
> Thanks for your patch, which is now commit cad439fc040efe5f
> ("crypto: api - Do not create test larvals if manager is disabled").
> 
> I have bisected a failure to mount the root file system on k210 to this
> commit.
> 
> Dmesg before/after:
> 
>       mmcblk0: mmc0:0000 SA04G 3.68 GiB
>       random: fast init done
>        mmcblk0: p1
>      -EXT4-fs (mmcblk0p1): mounted filesystem with ordered data mode. Opts: (null). Quota mode: disabled.
>      -VFS: Mounted root (ext4 filesystem) readonly on device 179:1.
>      +EXT4-fs (mmcblk0p1): Cannot load crc32c driver.
>      +VFS: Cannot open root device "mmcblk0p1" or unknown-block(179,1): error -80

p1 exist as the message 2 lines above shows. And since the mount error is -80
(ELIBBAD), it is really all about crypto. Since the default k210 config compile
everything in-kernel (no modules), it should work. Was crc32c compiled as a
module ? If yes, then the k210 will need to be booted with U-Boot and use a real
initrd, which likely will all end-up in a no memory situation. ext4 in itself
will consume way too much memory...

>      +Please append a correct "root=" boot option; here are the available partitions:
>      +b300         3858432 mmcblk0
>      + driver: mmcblk
>      +  b301         3854336 mmcblk0p1 00000000-01
> 
>> --- a/crypto/algapi.c
>> +++ b/crypto/algapi.c
>> @@ -216,6 +216,32 @@ void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
>> }
>> EXPORT_SYMBOL_GPL(crypto_remove_spawns);
>>
>> +static struct crypto_larval *crypto_alloc_test_larval(struct crypto_alg *alg)
>> +{
>> +	struct crypto_larval *larval;
>> +
>> +	if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER))
>> +		return NULL;
>> +
>> +	larval = crypto_larval_alloc(alg->cra_name,
>> +				     alg->cra_flags | CRYPTO_ALG_TESTED, 0);
>> +	if (IS_ERR(larval))
>> +		return larval;
>> +
>> +	larval->adult = crypto_mod_get(alg);
>> +	if (!larval->adult) {
>> +		kfree(larval);
>> +		return ERR_PTR(-ENOENT);
>> +	}
>> +
>> +	refcount_set(&larval->alg.cra_refcnt, 1);
>> +	memcpy(larval->alg.cra_driver_name, alg->cra_driver_name,
>> +	       CRYPTO_MAX_ALG_NAME);
>> +	larval->alg.cra_priority = alg->cra_priority;
>> +
>> +	return larval;
>> +}
>> +
>> static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg)
>> {
>> 	struct crypto_alg *q;
>> @@ -250,31 +276,20 @@ static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg)
>> 			goto err;
>> 	}
>>
>> -	larval = crypto_larval_alloc(alg->cra_name,
>> -				     alg->cra_flags | CRYPTO_ALG_TESTED, 0);
>> +	larval = crypto_alloc_test_larval(alg);
>> 	if (IS_ERR(larval))
>> 		goto out;
>>
>> -	ret = -ENOENT;
>> -	larval->adult = crypto_mod_get(alg);
>> -	if (!larval->adult)
>> -		goto free_larval;
>> -
>> -	refcount_set(&larval->alg.cra_refcnt, 1);
>> -	memcpy(larval->alg.cra_driver_name, alg->cra_driver_name,
>> -	       CRYPTO_MAX_ALG_NAME);
>> -	larval->alg.cra_priority = alg->cra_priority;
>> -
>> 	list_add(&alg->cra_list, &crypto_alg_list);
>> -	list_add(&larval->alg.cra_list, &crypto_alg_list);
>> +
>> +	if (larval)
>> +		list_add(&larval->alg.cra_list, &crypto_alg_list);
>>
>> 	crypto_stats_init(alg);
>>
>> out:
>> 	return larval;
>>
>> -free_larval:
>> -	kfree(larval);
>> err:
>> 	larval = ERR_PTR(ret);
>> 	goto out;
>> @@ -403,10 +418,11 @@ int crypto_register_alg(struct crypto_alg *alg)
>> 	down_write(&crypto_alg_sem);
>> 	larval = __crypto_register_alg(alg);
>> 	test_started = static_key_enabled(&crypto_boot_test_finished);
>> -	larval->test_started = test_started;
>> +	if (!IS_ERR_OR_NULL(larval))
>> +		larval->test_started = test_started;
>> 	up_write(&crypto_alg_sem);
>>
>> -	if (IS_ERR(larval))
>> +	if (IS_ERR_OR_NULL(larval))
>> 		return PTR_ERR(larval);
>>
>> 	if (test_started)
>> @@ -616,8 +632,8 @@ int crypto_register_instance(struct crypto_template *tmpl,
>> 	larval = __crypto_register_alg(&inst->alg);
>> 	if (IS_ERR(larval))
>> 		goto unlock;
>> -
>> -	larval->test_started = true;
>> +	else if (larval)
>> +		larval->test_started = true;
>>
>> 	hlist_add_head(&inst->list, &tmpl->instances);
>> 	inst->tmpl = tmpl;
>> @@ -626,7 +642,7 @@ int crypto_register_instance(struct crypto_template *tmpl,
>> 	up_write(&crypto_alg_sem);
>>
>> 	err = PTR_ERR(larval);
>> -	if (IS_ERR(larval))
>> +	if (IS_ERR_OR_NULL(larval))
>> 		goto err;
>>
>> 	crypto_wait_for_test(larval);
>> diff --git a/crypto/api.c b/crypto/api.c
>> index ee5991fe11f8..cf0869dd130b 100644
>> --- a/crypto/api.c
>> +++ b/crypto/api.c
>> @@ -167,11 +167,8 @@ void crypto_wait_for_test(struct crypto_larval *larval)
>> 	int err;
>>
>> 	err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult);
>> -	if (err != NOTIFY_STOP) {
>> -		if (WARN_ON(err != NOTIFY_DONE))
>> -			goto out;
>> -		crypto_alg_tested(larval->alg.cra_driver_name, 0);
>> -	}
>> +	if (WARN_ON_ONCE(err != NOTIFY_STOP))
>> +		goto out;
>>
>> 	err = wait_for_completion_killable(&larval->completion);
>> 	WARN_ON(err);
> 
> Gr{oetje,eeting}s,
> 
>  						Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>  							    -- Linus Torvalds
> 


-- 
Damien Le Moal
Western Digital Research