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 56A0FC04A95 for ; Fri, 23 Sep 2022 17:03:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231777AbiIWRDy (ORCPT ); Fri, 23 Sep 2022 13:03:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231613AbiIWRDw (ORCPT ); Fri, 23 Sep 2022 13:03:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5684F14A7B5 for ; Fri, 23 Sep 2022 10:03:51 -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 C4DC761255; Fri, 23 Sep 2022 17:03:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0505C433C1; Fri, 23 Sep 2022 17:03:49 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="a/cNt+jd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1663952628; 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=zHOgIOddNY860ZL19g2r4MW0E1ZbKOT+NC2vMETCNx4=; b=a/cNt+jdPiQOtxSkqLqKafMnsloCi6S6/jZ1RbPyPypuJKp6gtBwWl7WTOPO+6+GwlxRv4 PfGxYe7gcYa+mjaAFrxp7IzMbkJfCt9yxJ9+mBm/i6Hbd8OZ4XRGNJsT/7QBjAdyzG9o/E AjYWZvVsrfs0Sht8UyVHiQEzUK9/8hk= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id d2b20c29 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Fri, 23 Sep 2022 17:03:48 +0000 (UTC) From: "Jason A. Donenfeld" To: Geert Uytterhoeven , linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org Cc: "Jason A. Donenfeld" Subject: [PATCH v3 2/3] m68k: virt: generate new RNG seed on reboot Date: Fri, 23 Sep 2022 19:03:39 +0200 Message-Id: <20220923170340.4099226-2-Jason@zx2c4.com> In-Reply-To: <20220923170340.4099226-1-Jason@zx2c4.com> References: <20220923170340.4099226-1-Jason@zx2c4.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-m68k@vger.kernel.org Rather than rebooting into a system with no entropy, regenerate the RNG seed before rebooting, so that the new system has a fresh seed. Fixes: a1ee38ab1a75 ("m68k: virt: Use RNG seed from bootinfo block") Signed-off-by: Jason A. Donenfeld --- arch/m68k/virt/config.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/m68k/virt/config.c b/arch/m68k/virt/config.c index 4ab22946ff68..d4627840e35b 100644 --- a/arch/m68k/virt/config.c +++ b/arch/m68k/virt/config.c @@ -45,10 +45,18 @@ static void virt_halt(void) ; } +static const struct bi_record *rng_seed_record; + static void virt_reset(void) { void __iomem *base = (void __iomem *)virt_bi_data.ctrl.mmio; + if (rng_seed_record && rng_seed_record->size > sizeof(*rng_seed_record) + 2) { + u16 len = rng_seed_record->size - sizeof(*rng_seed_record) - 2; + get_random_bytes((u8 *)rng_seed_record->data + 2, len); + *(u16 *)rng_seed_record->data = cpu_to_be16(len); + } + iowrite32be(CMD_RESET, base + VIRT_CTRL_REG_CMD); local_irq_disable(); while (1) @@ -101,6 +109,8 @@ int __init virt_parse_bootinfo(const struct bi_record *record) * length to prevent kexec from using it. */ memzero_explicit((void *)data, len + 2); + /* Store a reference to be filled in on reboot. */ + rng_seed_record = record; break; } default: -- 2.37.3