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 CEB95C43334 for ; Thu, 23 Jun 2022 17:00:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233016AbiFWRAR (ORCPT ); Thu, 23 Jun 2022 13:00:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232773AbiFWQt6 (ORCPT ); Thu, 23 Jun 2022 12:49:58 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E17CA2BE3; Thu, 23 Jun 2022 09:47:53 -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 sin.source.kernel.org (Postfix) with ESMTPS id 2F0E6CE25D9; Thu, 23 Jun 2022 16:47:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35B1FC341C4; Thu, 23 Jun 2022 16:47:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656002870; bh=lyf7a//WFOH0mnpMYj+NUszJabjWPn0lwSpZWcIxuH4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kBgGnlckW07wcySnzhzMAN6AQ7tFEUkCSKzw3tLexKze1FgfZn3JS7QxGbTByZJDG aCLl3zlt2M2mxAnCLVzII96mCKyjfSNtKFLLKtVz5pXA57N2Xk55FknDC3fze4MxAZ q3YLJmfm231Y4M93qXgAOiYsMjL0BpTlmzQElgVo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Lutomirski , Theodore Tso , "Jason A. Donenfeld" Subject: [PATCH 4.9 054/264] random: Add a urandom_read_nowait() for random APIs that dont warn Date: Thu, 23 Jun 2022 18:40:47 +0200 Message-Id: <20220623164345.601401823@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: Andy Lutomirski commit c6f1deb158789abba02a7eba600747843eeb3a57 upstream. /dev/random and getrandom() never warn. Split the meat of urandom_read() into urandom_read_nowarn() and leave the warning code in urandom_read(). This has no effect on kernel behavior, but it makes subsequent patches more straightforward. It also makes the fact that getrandom() never warns more obvious. Signed-off-by: Andy Lutomirski Link: https://lore.kernel.org/r/c87ab200588de746431d9f916501ef11e5242b13.1577088521.git.luto@kernel.org Signed-off-by: Theodore Ts'o Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman --- drivers/char/random.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -2015,11 +2015,22 @@ random_read(struct file *file, char __us } static ssize_t +urandom_read_nowarn(struct file *file, char __user *buf, size_t nbytes, + loff_t *ppos) +{ + int ret; + + nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3)); + ret = extract_crng_user(buf, nbytes); + trace_urandom_read(8 * nbytes, 0, ENTROPY_BITS(&input_pool)); + return ret; +} + +static ssize_t urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) { unsigned long flags; static int maxwarn = 10; - int ret; if (!crng_ready() && maxwarn > 0) { maxwarn--; @@ -2031,10 +2042,8 @@ urandom_read(struct file *file, char __u crng_init_cnt = 0; spin_unlock_irqrestore(&primary_crng.lock, flags); } - nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3)); - ret = extract_crng_user(buf, nbytes); - trace_urandom_read(8 * nbytes, 0, ENTROPY_BITS(&input_pool)); - return ret; + + return urandom_read_nowarn(file, buf, nbytes, ppos); } static unsigned int @@ -2194,7 +2203,7 @@ SYSCALL_DEFINE3(getrandom, char __user * if (unlikely(ret)) return ret; } - return urandom_read(NULL, buf, count, NULL); + return urandom_read_nowarn(NULL, buf, count, NULL); } /********************************************************************