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 9A3D2C433F5 for ; Fri, 27 May 2022 08:58:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350126AbiE0I6z (ORCPT ); Fri, 27 May 2022 04:58:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345982AbiE0I6E (ORCPT ); Fri, 27 May 2022 04:58:04 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 42323119909; Fri, 27 May 2022 01:54:46 -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 666DA61D52; Fri, 27 May 2022 08:54:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3923AC385A9; Fri, 27 May 2022 08:54:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1653641685; bh=++xc5O0Pwzj5zTbMW+RdWvafvORy33rPu/1F0IGR7Uw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Eee3oIAUoQTm8G5AeFhfGPKj7MzpU8fGv/mBbXFpmPxVrJ9N63UZYoZ4tI6QaiiAl kd542vekUCQCCDlzaHrBlrgT3VvdfPnyui0HGu0bmJsbRBmIXjkQy4uQNvt1vON3B5 jy2c3uP7fg7WURbG9ju2kdA/KPRfN9et2OrAYvCk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dominik Brodowski , "Jason A. Donenfeld" Subject: [PATCH 5.18 34/47] random: credit architectural init the exact amount Date: Fri, 27 May 2022 10:50:14 +0200 Message-Id: <20220527084807.032837553@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220527084801.223648383@linuxfoundation.org> References: <20220527084801.223648383@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: "Jason A. Donenfeld" commit 12e45a2a6308105469968951e6d563e8f4fea187 upstream. RDRAND and RDSEED can fail sometimes, which is fine. We currently initialize the RNG with 512 bits of RDRAND/RDSEED. We only need 256 bits of those to succeed in order to initialize the RNG. Instead of the current "all or nothing" approach, actually credit these contributions the amount that is actually contributed. Reviewed-by: Dominik Brodowski Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman --- drivers/char/random.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -899,9 +899,8 @@ early_param("random.trust_bootloader", p */ int __init random_init(const char *command_line) { - size_t i; ktime_t now = ktime_get_real(); - bool arch_init = true; + unsigned int i, arch_bytes; unsigned long rv; #if defined(LATENT_ENTROPY_PLUGIN) @@ -909,11 +908,12 @@ int __init random_init(const char *comma _mix_pool_bytes(compiletime_seed, sizeof(compiletime_seed)); #endif - for (i = 0; i < BLAKE2S_BLOCK_SIZE; i += sizeof(rv)) { + for (i = 0, arch_bytes = BLAKE2S_BLOCK_SIZE; + i < BLAKE2S_BLOCK_SIZE; i += sizeof(rv)) { if (!arch_get_random_seed_long_early(&rv) && !arch_get_random_long_early(&rv)) { rv = random_get_entropy(); - arch_init = false; + arch_bytes -= sizeof(rv); } _mix_pool_bytes(&rv, sizeof(rv)); } @@ -924,8 +924,8 @@ int __init random_init(const char *comma if (crng_ready()) crng_reseed(); - else if (arch_init && trust_cpu) - credit_init_bits(BLAKE2S_BLOCK_SIZE * 8); + else if (trust_cpu) + credit_init_bits(arch_bytes * 8); return 0; }