From patchwork Wed Jul 16 02:48:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Lutomirski X-Patchwork-Id: 4564271 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7701E9F295 for ; Wed, 16 Jul 2014 02:49:27 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AF55F201CD for ; Wed, 16 Jul 2014 02:49:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D4392201C7 for ; Wed, 16 Jul 2014 02:49:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759923AbaGPCtL (ORCPT ); Tue, 15 Jul 2014 22:49:11 -0400 Received: from mail-pa0-f53.google.com ([209.85.220.53]:61910 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759166AbaGPCsf (ORCPT ); Tue, 15 Jul 2014 22:48:35 -0400 Received: by mail-pa0-f53.google.com with SMTP id kq14so407836pab.40 for ; Tue, 15 Jul 2014 19:48:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=Tv/2XURNG9gclRt35XrGIcZZ2KmYrUSv+Tc4BO6GMgk=; b=iPITzgm8cx73XLWqph1d9hJnq7KeXNJk1dSdNCd8DMhCjoKYCwsc8ZZRNX3WaQRE5Z X1OTchT+L1WOrEdKqi7vQhT78ppS/XhuvaWCvVc3qMMnBPK4pAULC/l6GdOe4e0liREE /DUuuSCuY4PsQFJfMztsY1cI3i+7lPLW18aoQ7duVOoBnC3Jdq6BZJKECkfQLRAwgK6/ gnca1u4gcIoCWFwOd38+vcsGUPxLiEI8lpwlTB2FDf5uoRlZPk0KUnVh+D3CwdqL4Our mfieblzmLubUPW12Agfgy0Mv+rndHioUWzVv0L/E8AJpCFZyP9jfcLjlDC+GxhyZ4Mxp ZIqQ== X-Gm-Message-State: ALoCoQnKKNbXUbyqftM1ty6NfD+h3RL1asYfiiGgLUhU2VKTYDexBFlXtg83UB3LLVaQ17VRZyTd X-Received: by 10.70.103.74 with SMTP id fu10mr12822417pdb.119.1405478914963; Tue, 15 Jul 2014 19:48:34 -0700 (PDT) Received: from localhost ([2001:5a8:4:83c0:fccf:79b7:dc5b:f307]) by mx.google.com with ESMTPSA id pm7sm20570833pdb.77.2014.07.15.19.48.32 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 15 Jul 2014 19:48:33 -0700 (PDT) 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: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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); } /*