From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1950258AbcHROoo (ORCPT ); Thu, 18 Aug 2016 10:44:44 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36890 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1950187AbcHROLu (ORCPT ); Thu, 18 Aug 2016 10:11:50 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Theodore Tso Subject: [PATCH 4.7 082/186] random: initialize the non-blocking pool via add_hwgenerator_randomness() Date: Thu, 18 Aug 2016 15:58:19 +0200 Message-Id: <20160818135935.637486448@linuxfoundation.org> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20160818135932.219369981@linuxfoundation.org> References: <20160818135932.219369981@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Theodore Ts'o commit 3371f3da08cff4b75c1f2dce742d460539d6566d upstream. If we have a hardware RNG and are using the in-kernel rngd, we should use this to initialize the non-blocking pool so that getrandom(2) doesn't block unnecessarily. Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- drivers/char/random.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1853,12 +1853,18 @@ void add_hwgenerator_randomness(const ch { struct entropy_store *poolp = &input_pool; - /* Suspend writing if we're above the trickle threshold. - * We'll be woken up again once below random_write_wakeup_thresh, - * or when the calling thread is about to terminate. - */ - wait_event_interruptible(random_write_wait, kthread_should_stop() || + if (unlikely(nonblocking_pool.initialized == 0)) + poolp = &nonblocking_pool; + else { + /* Suspend writing if we're above the trickle + * threshold. We'll be woken up again once below + * random_write_wakeup_thresh, or when the calling + * thread is about to terminate. + */ + wait_event_interruptible(random_write_wait, + kthread_should_stop() || ENTROPY_BITS(&input_pool) <= random_write_wakeup_bits); + } mix_pool_bytes(poolp, buffer, count); credit_entropy_bits(poolp, entropy); }