From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965399AbbEMT6D (ORCPT ); Wed, 13 May 2015 15:58:03 -0400 Received: from mail.eperm.de ([89.247.134.16]:34783 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964916AbbEMT5y (ORCPT ); Wed, 13 May 2015 15:57:54 -0400 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 v6 1/5] random: Blocking API for accessing nonblocking_pool Date: Wed, 13 May 2015 21:54:41 +0200 Message-ID: <34087343.u7K3uzbyiZ@tachyon.chronox.de> User-Agent: KMail/4.14.7 (Linux/3.19.5-200.fc21.x86_64; KDE/4.14.7; x86_64; ; ) In-Reply-To: <1921857.OvxEu6y28S@tachyon.chronox.de> References: <1921857.OvxEu6y28S@tachyon.chronox.de> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 | 14 ++++++++++++++ include/linux/random.h | 1 + 2 files changed, 15 insertions(+) diff --git a/drivers/char/random.c b/drivers/char/random.c index 9cd6968..6f71354 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1245,6 +1245,20 @@ 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) +{ + if (unlikely(nonblocking_pool.initialized == 0)) + wait_event_interruptible(urandom_init_wait, + nonblocking_pool.initialized); + 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..0926d78 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); -- 2.1.0