From patchwork Wed Nov 16 16:16:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Jason A. Donenfeld" X-Patchwork-Id: 13045468 X-Patchwork-Delegate: herbert@gondor.apana.org.au 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 16D29C43219 for ; Wed, 16 Nov 2022 16:17:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233296AbiKPQRU (ORCPT ); Wed, 16 Nov 2022 11:17:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234897AbiKPQRH (ORCPT ); Wed, 16 Nov 2022 11:17:07 -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 B5DD156EDD; Wed, 16 Nov 2022 08:17:06 -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 7550DB81DA7; Wed, 16 Nov 2022 16:17:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B540C433C1; Wed, 16 Nov 2022 16:17:03 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="BnW7RkGC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1668615421; 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=v24y1wfuWLq5Cu92sfEtPK6DD/spL3fwX1JCpyFIa2M=; b=BnW7RkGC9Fcq2ZG1RT/d/CIyFvNnzxI+y3tkfmX8qqtcxb7VHTah3KU6Df9TGBZnCjZL2h 0CUAvsVt5vYzI7yOSV8tJkqq+2g8cFt4djJoqXUmtnOVb/wACoUWpyZt3MGKLIMK91kcRG YJqSKfBTQd6IdUnDbhvx9XW3ApqlwBA= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id fb4bb795 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Wed, 16 Nov 2022 16:17:01 +0000 (UTC) From: "Jason A. Donenfeld" To: linux-efi@vger.kernel.org, linux-crypto@vger.kernel.org Cc: "Jason A. Donenfeld" , Ard Biesheuvel , Lennart Poettering , Mike Galbraith , Sebastian Andrzej Siewior , Petr Mladek Subject: [PATCH RFC v1 2/6] vsprintf: initialize siphash key using notifier Date: Wed, 16 Nov 2022 17:16:38 +0100 Message-Id: <20221116161642.1670235-3-Jason@zx2c4.com> In-Reply-To: <20221116161642.1670235-1-Jason@zx2c4.com> References: <20221116161642.1670235-1-Jason@zx2c4.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Rather than polling every second, use the new notifier to do this at exactly the right moment. Cc: Mike Galbraith Cc: Sebastian Andrzej Siewior Cc: Petr Mladek Signed-off-by: Jason A. Donenfeld Reviewed-by: Petr Mladek --- lib/vsprintf.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 24f37bab8bc1..70aa5de3c330 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -41,6 +41,7 @@ #include #include #include +#include #ifdef CONFIG_BLOCK #include #endif @@ -752,26 +753,21 @@ early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable); static bool filled_random_ptr_key __read_mostly; static siphash_key_t ptr_key __read_mostly; -static void fill_ptr_key_workfn(struct work_struct *work); -static DECLARE_DELAYED_WORK(fill_ptr_key_work, fill_ptr_key_workfn); -static void fill_ptr_key_workfn(struct work_struct *work) +static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data) { - if (!rng_is_initialized()) { - queue_delayed_work(system_unbound_wq, &fill_ptr_key_work, HZ * 2); - return; - } - get_random_bytes(&ptr_key, sizeof(ptr_key)); /* Pairs with smp_rmb() before reading ptr_key. */ smp_wmb(); WRITE_ONCE(filled_random_ptr_key, true); + return 0; } static int __init vsprintf_init_hashval(void) { - fill_ptr_key_workfn(NULL); + static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key }; + notify_on_rng_initialized(&fill_ptr_key_nb); return 0; } subsys_initcall(vsprintf_init_hashval)