crypto: api - Do not create test larvals if manager is disabled

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: NNathan Chancellor <nathan@kernel.org>
Reported-by: NNaresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Nkernel test robot <lkp@intel.com>
Fixes: adad556e ("crypto: api - Fix built-in testing dependency failures")
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

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;
@@ -250,22 +276,13 @@ 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);
+
+	if (larval)
 		list_add(&larval->alg.cra_list, &crypto_alg_list);
 
 	crypto_stats_init(alg);
@@ -273,8 +290,6 @@ static struct crypto_larval *__crypto_register_alg(struct crypto_alg *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);
+	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)
@@ -616,7 +632,7 @@ int crypto_register_instance(struct crypto_template *tmpl,
 	larval = __crypto_register_alg(&inst->alg);
 	if (IS_ERR(larval))
 		goto unlock;
-
+	else if (larval)
 		larval->test_started = true;
 
 	hlist_add_head(&inst->list, &tmpl->instances);
@@ -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);

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))
+	if (WARN_ON_ONCE(err != NOTIFY_STOP))
 		goto out;
-		crypto_alg_tested(larval->alg.cra_driver_name, 0);
-	}
 
 	err = wait_for_completion_killable(&larval->completion);
 	WARN_ON(err);