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 22B74C433EF for ; Sun, 13 Mar 2022 00:01:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233108AbiCMACV (ORCPT ); Sat, 12 Mar 2022 19:02:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229836AbiCMACU (ORCPT ); Sat, 12 Mar 2022 19:02:20 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 298B91F082C for ; Sat, 12 Mar 2022 16:01:14 -0800 (PST) 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 ams.source.kernel.org (Postfix) with ESMTPS id CB948B80A0B for ; Sun, 13 Mar 2022 00:01:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA5F7C340EB; Sun, 13 Mar 2022 00:01:10 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="QSbe/gb7" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1647129669; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jl/NsDFMHvohCwOgOfjISqYCipfgNcDxWeieDwhb/5c=; b=QSbe/gb7cZryADEuy+wOVq6B/FRcSHA0nBhnvDfPiRsYz6nwyqQp/uUFvocn0Cns4M0fe7 1Zj6ZrMApGdDJNmwYaweGrKW9WrDpNzlEfdoWwC2eZQzbFEqbV0WhAoHCjppqwRHsjKnop jL6f1UentFN2lzGQI05db/q0ZJkjl7Q= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 745b9e77 (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO); Sun, 13 Mar 2022 00:01:08 +0000 (UTC) From: "Jason A. Donenfeld" To: linux-kernel@vger.kernel.org Cc: "Jason A. Donenfeld" , Theodore Ts'o , Dominik Brodowski Subject: [PATCH v2] random: make consistent usage of crng_ready() Date: Sat, 12 Mar 2022 17:00:56 -0700 Message-Id: <20220313000056.7421-1-Jason@zx2c4.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Rather than sometimes checking `crng_init < 2`, we should always use the crng_ready() macro, so that should we change anything later, it's consistent. Additionally, that macro already has a likely() around it, which means we don't need to open code our own likely() and unlikely() annotations. Cc: Theodore Ts'o Reviewed-by: Dominik Brodowski Signed-off-by: Jason A. Donenfeld --- drivers/char/random.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index edb5b06544da..596dc664b5bd 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -123,18 +123,13 @@ static void try_to_generate_entropy(void); */ int wait_for_random_bytes(void) { - if (likely(crng_ready())) - return 0; - - do { + while (!crng_ready()) { int ret; ret = wait_event_interruptible_timeout(crng_init_wait, crng_ready(), HZ); if (ret) return ret > 0 ? 0 : ret; - try_to_generate_entropy(); - } while (!crng_ready()); - + } return 0; } EXPORT_SYMBOL(wait_for_random_bytes); @@ -289,7 +284,7 @@ static void crng_reseed(bool force) ++next_gen; WRITE_ONCE(base_crng.generation, next_gen); WRITE_ONCE(base_crng.birth, jiffies); - if (crng_init < 2) { + if (!crng_ready()) { crng_init = 2; finalize_init = true; } @@ -352,7 +347,7 @@ static void crng_make_state(u32 chacha_state[CHACHA_STATE_WORDS], * ready, we do fast key erasure with the base_crng directly, because * this is what crng_pre_init_inject() mutates during early init. */ - if (unlikely(!crng_ready())) { + if (!crng_ready()) { bool ready; spin_lock_irqsave(&base_crng.lock, flags); @@ -795,7 +790,7 @@ static void credit_entropy_bits(size_t nbits) entropy_count = min_t(unsigned int, POOL_BITS, orig + add); } while (cmpxchg(&input_pool.entropy_count, orig, entropy_count) != orig); - if (crng_init < 2 && entropy_count >= POOL_MIN_BITS) + if (!crng_ready() && entropy_count >= POOL_MIN_BITS) crng_reseed(false); } @@ -957,7 +952,7 @@ int __init rand_initialize(void) extract_entropy(base_crng.key, sizeof(base_crng.key)); ++base_crng.generation; - if (arch_init && trust_cpu && crng_init < 2) { + if (arch_init && trust_cpu && !crng_ready()) { crng_init = 2; pr_notice("crng init done (trusting CPU's manufacturer)\n"); } @@ -1551,7 +1546,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg) case RNDRESEEDCRNG: if (!capable(CAP_SYS_ADMIN)) return -EPERM; - if (crng_init < 2) + if (!crng_ready()) return -ENODATA; crng_reseed(false); return 0; -- 2.35.1