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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 38F24C433EF for ; Tue, 5 Jul 2022 23:13:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:References: In-Reply-To:Subject:CC:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=O3W3xkYpAOK8U7o3FC/ZGXzyZxPYJBNyIsG0/n3VC0A=; b=Z5KRefJa/YTWlS uIBNSlqWpZocVXrI4mx/MqAzrhH60JIZiADQ7uaBjgcUS1JRNk4hR/4ebEUC8Hr5KRV6lhqqIA60s WSk3tZ/IeAwhYGvdxJDtWCaVfz2NbMjhGbJXW5zZPTIoYPzifbmdL2YwOhUKjeUS0bktv3p2FjCXq vqy/apxcZfw8/9C1ypEitB6oCgscuPhelijh4S/bBAkaAxJmKJNJiqyPv6SZ6nc4xMXJE1ZXHwWG5 Sl+IEH8t2ssVLGQe6FLOwxivymkS1YDRdXe7FHf92Hwie4OUggQrd6NlWBbKm5yuYfeP0O000NqbT cAgMC7fl3bYGqq0va1oA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8riQ-003WW6-RI; Tue, 05 Jul 2022 23:12:22 +0000 Received: from terminus.zytor.com ([198.137.202.136] helo=mail.zytor.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8riO-003WOr-6C for linux-arm-kernel@lists.infradead.org; Tue, 05 Jul 2022 23:12:21 +0000 Received: from [127.0.0.1] ([73.223.250.219]) (authenticated bits=0) by mail.zytor.com (8.17.1/8.15.2) with ESMTPSA id 265NBnGE1003711 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Tue, 5 Jul 2022 16:11:50 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 265NBnGE1003711 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2022060401; t=1657062712; bh=Y98dqt5En+kS/P/7IMzby9wcUq/7fVTjOsj4m2LkPGI=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=KoHiZKsEicJF3HWW8BYUbNDtijdyk2YC30lpGok5A71WKH5jN4kSF+1k/ILd0x9By qt8xe3MS+M3LxdPaft1n7lcyMixtVdJ5SQYbrobuHAXvXZD91dHJDhsiyrj0xX6oEB UzBMdQKEXifwQOtQj+6um92/xSJJMJAJk/eweAx0I6RYNd0HPoR17l0lZTdhk7AUif NSyyZN5L500jyETF72C6IrByv8jv42HDJSrxzOzuSo6byDKD6nExbO6sf5LLBoXwBl hJl0pswjsA5H80PdAU7gimYJT6uwlh8+RWtIOHDI250cjEOA3EOFzWqjhIcySx1ZiD mZSs9tkVChZvA== Date: Tue, 05 Jul 2022 16:11:45 -0700 From: "H. Peter Anvin" To: Borislav Petkov CC: "Jason A. Donenfeld" , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, Catalin Marinas , Will Deacon , Michael Ellerman , Heiko Carstens , Alexander Gordeev , Thomas Gleixner , Greg Kroah-Hartman , Arnd Bergmann Subject: Re: [PATCH] random: remove CONFIG_ARCH_RANDOM and "nordrand" User-Agent: K-9 Mail for Android In-Reply-To: References: <20220705190121.293703-1-Jason@zx2c4.com> <11C903CC-22A7-48EE-AD63-E71CC8D28B88@zytor.com> Message-ID: <805B66CB-D847-4547-B6EE-C4FB72B75765@zytor.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220705_161220_276090_F2BAB2D5 X-CRM114-Status: GOOD ( 10.06 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On July 5, 2022 3:00:04 PM PDT, Borislav Petkov wrote: >On Tue, Jul 05, 2022 at 02:50:34PM -0700, H. Peter Anvin wrote: >> It's just math. The only variable is your confidence level, i.e. at >> what level do you decide that the likelihood of pure chance is way >> smaller than the likelihood of hardware failure. > >That might be but the likelyhood of certain BIOSes dropping the ball >after resume is 100%: > >7879fc4bdc75 ("x86/rdrand: Sanity-check RDRAND output") > What I'm wondering is if we shouldn't be simply instrument *every* invocation, and set the trust to zero if we ever trip it. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel