From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3C08CCA48A for ; Thu, 23 Jun 2022 16:47:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232542AbiFWQrY (ORCPT ); Thu, 23 Jun 2022 12:47:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232471AbiFWQqp (ORCPT ); Thu, 23 Jun 2022 12:46:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F42749B48; Thu, 23 Jun 2022 09:46:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 195F061F8B; Thu, 23 Jun 2022 16:46:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED9A7C3411B; Thu, 23 Jun 2022 16:46:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656002798; bh=W8dq3uMApTVef6GoyPpbGGEqhGowcse71vUYaDeYi34=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JvA0GxQAAn+oCTuduJlfb76Bz9FKvWPsUPi1aDscGGB7Z5TJ4Rzdz9r3tl/E0M/Uq WycE3mcvNsLqok5kIZjjOGzPZdRk2DBqxCuwgEyNP1Sk2Z1hRHk0vrkO3ruhC8/wCN G7YAjdO99ArWa0AjH1B4IfGTBaFIFVlTsAFjl5JA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rasmus Villemoes , Theodore Tso , "Jason A. Donenfeld" Subject: [PATCH 4.9 029/264] drivers/char/random.c: remove unused dont_count_entropy Date: Thu, 23 Jun 2022 18:40:22 +0200 Message-Id: <20220623164344.893849680@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220623164344.053938039@linuxfoundation.org> References: <20220623164344.053938039@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rasmus Villemoes commit 5e747dd9be54be190dd6ebeebf4a4a01ba765625 upstream. Ever since "random: kill dead extract_state struct" [1], the dont_count_entropy member of struct timer_rand_state has been effectively unused. Since it hasn't found a new use in 12 years, it's probably safe to finally kill it. [1] Pre-git, https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=c1c48e61c251f57e7a3f1bf11b3c462b2de9dcb5 Signed-off-by: Rasmus Villemoes Signed-off-by: Theodore Ts'o Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman --- drivers/char/random.c | 55 +++++++++++++++++++++++--------------------------- 1 file changed, 26 insertions(+), 29 deletions(-) --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1130,7 +1130,6 @@ static ssize_t extract_crng_user(void __ struct timer_rand_state { cycles_t last_time; long last_delta, last_delta2; - unsigned dont_count_entropy:1; }; #define INIT_TIMER_RAND_STATE { INITIAL_JIFFIES, }; @@ -1194,35 +1193,33 @@ static void add_timer_randomness(struct * We take into account the first, second and third-order deltas * in order to make our estimate. */ + delta = sample.jiffies - state->last_time; + state->last_time = sample.jiffies; + + delta2 = delta - state->last_delta; + state->last_delta = delta; + + delta3 = delta2 - state->last_delta2; + state->last_delta2 = delta2; + + if (delta < 0) + delta = -delta; + if (delta2 < 0) + delta2 = -delta2; + if (delta3 < 0) + delta3 = -delta3; + if (delta > delta2) + delta = delta2; + if (delta > delta3) + delta = delta3; + + /* + * delta is now minimum absolute delta. + * Round down by 1 bit on general principles, + * and limit entropy entimate to 12 bits. + */ + credit_entropy_bits(r, min_t(int, fls(delta>>1), 11)); - if (!state->dont_count_entropy) { - delta = sample.jiffies - state->last_time; - state->last_time = sample.jiffies; - - delta2 = delta - state->last_delta; - state->last_delta = delta; - - delta3 = delta2 - state->last_delta2; - state->last_delta2 = delta2; - - if (delta < 0) - delta = -delta; - if (delta2 < 0) - delta2 = -delta2; - if (delta3 < 0) - delta3 = -delta3; - if (delta > delta2) - delta = delta2; - if (delta > delta3) - delta = delta3; - - /* - * delta is now minimum absolute delta. - * Round down by 1 bit on general principles, - * and limit entropy entimate to 12 bits. - */ - credit_entropy_bits(r, min_t(int, fls(delta>>1), 11)); - } preempt_enable(); }