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 38A38CCA482 for ; Mon, 20 Jun 2022 14:02:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344105AbiFTOBw (ORCPT ); Mon, 20 Jun 2022 10:01:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350610AbiFTNxp (ORCPT ); Mon, 20 Jun 2022 09:53:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07F001A3B0; Mon, 20 Jun 2022 06:20:12 -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 CBAEC60C8B; Mon, 20 Jun 2022 13:10:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BECFEC3411B; Mon, 20 Jun 2022 13:10:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655730639; bh=uWs2zUwT/SVjM5aswnIC6LTcAQBCGhcDUTFAe2cHKu0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2lfG7Gss2cBf55fKGmPxS6rcKud2kh+73BW5dgVGq01JY7ZXtQPoBt0lBWkk6nah/ B77tB0TuR8kbB3kqQplfCzqaDjmA6ba4FiZKXLLuoFUkd8t2fDoiN4CgmcnGE3mUVJ 9QpXmcHE4IBYuqjfs6NEkGHo7NYRIuT2M5az0QRQ= 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 5.4 010/240] random: Add a urandom_read_nowait() for random APIs that dont warn Date: Mon, 20 Jun 2022 14:48:31 +0200 Message-Id: <20220620124738.106403104@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220620124737.799371052@linuxfoundation.org> References: <20220620124737.799371052@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: stable@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 @@ -2043,11 +2043,22 @@ 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--; @@ -2059,10 +2070,8 @@ 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 __poll_t @@ -2224,7 +2233,7 @@ 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); } /********************************************************************