Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759689AbaGPCsp (ORCPT ); Tue, 15 Jul 2014 22:48:45 -0400 Received: from mail-pa0-f43.google.com ([209.85.220.43]:55822 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759176AbaGPCsf (ORCPT ); Tue, 15 Jul 2014 22:48:35 -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 , Andy Lutomirski Subject: [PATCH 3/4] random: Seed pools from arch_get_slow_rng_u64 at startup Date: Tue, 15 Jul 2014 19:48:09 -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 should help solve the problem of guests starting out with predictable RNG state. Signed-off-by: Andy Lutomirski --- drivers/char/random.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 0a7ac0a..bd88a24 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1248,7 +1248,7 @@ EXPORT_SYMBOL(get_random_bytes_arch); */ static void init_std_data(struct entropy_store *r) { - int i; + int i, slow_rng_bits = 0; ktime_t now = ktime_get_real(); unsigned long rv; @@ -1261,6 +1261,18 @@ static void init_std_data(struct entropy_store *r) mix_pool_bytes(r, &rv, sizeof(rv), NULL); } mix_pool_bytes(r, utsname(), sizeof(*(utsname())), NULL); + + for (i = 0; i < 4; i++) { + u64 rv64; + + if (arch_get_slow_rng_u64(&rv64)) { + mix_pool_bytes(r, &rv64, sizeof(rv64), NULL); + slow_rng_bits += 8 * sizeof(rv64); + } + } + if (slow_rng_bits) + pr_info("random: seeded %s pool with %d bits of arch slow rng data\n", + r->name, 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/