From patchwork Tue May 19 14:36:58 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephan Mueller X-Patchwork-Id: 6438531 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 A00A6C0432 for ; Tue, 19 May 2015 14:38:29 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 27C21205E7 for ; Tue, 19 May 2015 14:38:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 437B520320 for ; Tue, 19 May 2015 14:38:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933014AbbESOhD (ORCPT ); Tue, 19 May 2015 10:37:03 -0400 Received: from mail.eperm.de ([89.247.134.16]:57976 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932951AbbESOhA (ORCPT ); Tue, 19 May 2015 10:37:00 -0400 Received: from tauon.localnet (mail.eperm.de [89.247.134.16]) by mail.eperm.de (Postfix) with ESMTPSA id B559B2A03EC; Tue, 19 May 2015 16:36:58 +0200 (CEST) From: Stephan Mueller To: Herbert Xu Cc: Theodore Ts'o , pebolle@tiscali.nl, andreas.steffen@strongswan.org, sandyinchina@gmail.com, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org Subject: Re: [PATCH v6 1/5] random: Blocking API for accessing nonblocking_pool Date: Tue, 19 May 2015 16:36:58 +0200 Message-ID: <1889464.W6X1COIBGJ@tauon> User-Agent: KMail/4.14.6 (Linux/3.19.5-200.fc21.x86_64; KDE/4.14.6; x86_64; ; ) In-Reply-To: <20150519143022.GC32663@gondor.apana.org.au> References: <1921857.OvxEu6y28S@tachyon.chronox.de> <1637466.ZUdUCXWXVs@tauon> <20150519143022.GC32663@gondor.apana.org.au> 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 Am Dienstag, 19. Mai 2015, 22:30:22 schrieb Herbert Xu: Hi Herbert, >On Tue, May 19, 2015 at 04:27:54PM +0200, Stephan Mueller wrote: >> The current modification with patch 1 to random.c is the smallest change to >> date. Is that then appropriate? >> >> Herbert, based on your comment now, would the currently discussed patch >> with >> waiting in the work queue in patch 3 appropriate? Or what would you like to >> see changed? > >Sorry but I have lost track as to which patch is which. Please post >the changes to random.c and we can all take a look. It would be the patch from the start of the thread as follows. 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(+) extern int random_int_secret_init(void); -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html 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]);