From patchwork Tue Nov 22 02:04:03 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: 627801 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 68897C4321E for ; Tue, 22 Nov 2022 02:04:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232506AbiKVCEl (ORCPT ); Mon, 21 Nov 2022 21:04:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232459AbiKVCEc (ORCPT ); Mon, 21 Nov 2022 21:04:32 -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 5F26DE14D7; Mon, 21 Nov 2022 18:04:25 -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 2403BB818E7; Tue, 22 Nov 2022 02:04:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4042BC433B5; Tue, 22 Nov 2022 02:04:22 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="Dp148rop" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1669082661; 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=CQp5Xt1b1pHaswbZ86gvO2c+Ls0o4Gj7yCvAYqghZs4=; b=Dp148ropguWfBS6U4rGunOxWu3O9SFddDB/Y0n7mciWLwD8rlXvuG2ujfQZvGZvlIqvs/e sqP6W2u3zp8d3lf/WsFe95jZ34Fyue6k6vMbgXrgaRdcAAguucHbIVpgRD3pu6f835hTtB wc/KbEFVHfZLX3ytWRL6oT1/oPa1qFM= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 8231b6b4 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Tue, 22 Nov 2022 02:04:21 +0000 (UTC) From: "Jason A. Donenfeld" To: linux-efi@vger.kernel.org, linux-crypto@vger.kernel.org, patches@lists.linux.dev, linux-kernel@vger.kernel.org, ardb@kernel.org Cc: "Jason A. Donenfeld" , Petr Mladek Subject: [PATCH v3 4/5] vsprintf: initialize siphash key using notifier Date: Tue, 22 Nov 2022 03:04:03 +0100 Message-Id: <20221122020404.3476063-5-Jason@zx2c4.com> In-Reply-To: <20221122020404.3476063-1-Jason@zx2c4.com> References: <20221122020404.3476063-1-Jason@zx2c4.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Rather than polling every second, use the new notifier to do this at exactly the right moment. Reviewed-by: Petr Mladek Signed-off-by: Jason A. Donenfeld --- lib/vsprintf.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 24f37bab8bc1..2d11541ee561 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 NOTIFY_DONE; } 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 }; + execute_with_initialized_rng(&fill_ptr_key_nb); return 0; } subsys_initcall(vsprintf_init_hashval)