crypto_alloc_rng
rng = crypto_alloc_rng(name, type, mask);
drbg->jent = crypto_alloc_rng("jitterentropy_rng", 0, 0);
EXPORT_SYMBOL_GPL(crypto_alloc_rng);
rng = crypto_alloc_rng("stdrng", 0, 0);
drng = crypto_alloc_rng(driver, type, mask);
struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask);