Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760680AbaGPRrP (ORCPT ); Wed, 16 Jul 2014 13:47:15 -0400 Received: from mail-pa0-f45.google.com ([209.85.220.45]:53718 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760294AbaGPRqY (ORCPT ); Wed, 16 Jul 2014 13:46:24 -0400 From: Andy Lutomirski To: kvm@vger.kernel.org, "H. Peter Anvin" , "Theodore Ts'o" , linux-kernel@vger.kernel.org, Kees Cook , x86@kernel.org Cc: Daniel Borkmann , Srivatsa Vaddagiri , Raghavendra K T , Gleb Natapov , Paolo Bonzini , Andy Lutomirski Subject: [PATCH v2 4/5] random: Log how many bits we managed to seed with in init_std_data Date: Wed, 16 Jul 2014 10:45:59 -0700 Message-Id: X-Mailer: git-send-email 1.9.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is useful for making sure that init_std_data is working correctly and for allaying fear when this happens: random: xyz urandom read with SMALL_NUMBER bits of entropy available Signed-off-by: Andy Lutomirski --- drivers/char/random.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index e2c3d02..10e9642 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1251,12 +1251,16 @@ static void init_std_data(struct entropy_store *r) int i; ktime_t now = ktime_get_real(); unsigned long rv; + int arch_seed_bits = 0, arch_random_bits = 0, slow_rng_bits = 0; r->last_pulled = jiffies; mix_pool_bytes(r, &now, sizeof(now), NULL); for (i = r->poolinfo->poolbytes; i > 0; i -= sizeof(rv)) { - if (!arch_get_random_seed_long(&rv) && - !arch_get_random_long(&rv)) + if (arch_get_random_seed_long(&rv)) + arch_seed_bits += 8 * sizeof(rv); + else if (arch_get_random_long(&rv)) + arch_random_bits += 8 * sizeof(rv); + else rv = random_get_entropy(); mix_pool_bytes(r, &rv, sizeof(rv), NULL); } @@ -1265,10 +1269,14 @@ static void init_std_data(struct entropy_store *r) for (i = 0; i < 4; i++) { u64 rv64; - if (arch_get_slow_rng_u64(&rv64)) + if (arch_get_slow_rng_u64(&rv64)) { mix_pool_bytes(r, &rv64, sizeof(rv64), NULL); + slow_rng_bits += 8 * sizeof(rv64); } } + + pr_info("random: seeded %s pool with %d bits of arch random seed, %d bits of arch random, and %d bits of arch slow rng\n", + r->name, arch_seed_bits, arch_random_bits, slow_rng_bits); } /* -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/