From patchwork Wed May 20 17:44:39 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephan Mueller X-Patchwork-Id: 6448261 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: X-Original-To: patchwork-linux-crypto@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0A2F7C0432 for ; Wed, 20 May 2015 17:50:07 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3304D202FF for ; Wed, 20 May 2015 17:50:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3EC46202F8 for ; Wed, 20 May 2015 17:50:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754384AbbETRtc (ORCPT ); Wed, 20 May 2015 13:49:32 -0400 Received: from mail.eperm.de ([89.247.134.16]:58023 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754169AbbETRsa (ORCPT ); Wed, 20 May 2015 13:48:30 -0400 Received: from tachyon.chronox.de (mail.eperm.de [89.247.134.16]) by mail.eperm.de (Postfix) with ESMTPSA id 5D17F2A0602; Wed, 20 May 2015 19:48:26 +0200 (CEST) From: Stephan Mueller To: herbert@gondor.apana.org.au Cc: pebolle@tiscali.nl, andreas.steffen@strongswan.org, tytso@mit.edu, sandyinchina@gmail.com, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org Subject: [PATCH v7 1/5] random: Blocking API for accessing nonblocking_pool Date: Wed, 20 May 2015 19:44:39 +0200 Message-ID: <143216583.t5fUODkLsI@tachyon.chronox.de> User-Agent: KMail/4.14.7 (Linux/3.19.7-200.fc21.x86_64; KDE/4.14.7; x86_64; ; ) In-Reply-To: <1693038.ndeE0L22jl@tachyon.chronox.de> References: <1693038.ndeE0L22jl@tachyon.chronox.de> MIME-Version: 1.0 Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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 The added API calls provide a synchronous function call get_blocking_random_bytes where the caller is blocked until the nonblocking_pool is initialized. CC: Andreas Steffen CC: Theodore Ts'o CC: Sandy Harris Signed-off-by: Stephan Mueller --- drivers/char/random.c | 18 ++++++++++++++++++ include/linux/random.h | 1 + 2 files changed, 19 insertions(+) diff --git a/drivers/char/random.c b/drivers/char/random.c index 9cd6968..3d1c027 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1245,6 +1245,24 @@ void get_random_bytes(void *buf, int nbytes) EXPORT_SYMBOL(get_random_bytes); /* + * Equivalent function to get_random_bytes with the difference that this + * function blocks the request until the nonblocking_pool is initialized. + */ +void get_blocking_random_bytes(void *buf, int nbytes) +{ + int rc; + + if (unlikely(nonblocking_pool.initialized == 0)) { + do { + rc = wait_event_interruptible(urandom_init_wait, + nonblocking_pool.initialized); + } while (rc == -ERESTARTSYS); + } + extract_entropy(&nonblocking_pool, buf, nbytes, 0, 0); +} +EXPORT_SYMBOL(get_blocking_random_bytes); + +/* * This function will use the architecture-specific hardware random * number generator if it is available. The arch-specific hw RNG will * almost certainly be faster than what we can do in software, but it diff --git a/include/linux/random.h b/include/linux/random.h index b05856e..796267d 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -14,6 +14,7 @@ extern void add_input_randomness(unsigned int type, unsigned int code, extern void add_interrupt_randomness(int irq, int irq_flags); extern void get_random_bytes(void *buf, int nbytes); +extern void get_blocking_random_bytes(void *buf, int nbytes); extern void get_random_bytes_arch(void *buf, int nbytes); void generate_random_uuid(unsigned char uuid_out[16]); extern int random_int_secret_init(void);