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 X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25842C4708F for ; Thu, 3 Jun 2021 01:46:43 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id E4A3761182 for ; Thu, 3 Jun 2021 01:46:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E4A3761182 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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:References:In-Reply-To: Date:Cc:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=p+u6MRZefOm3xfMwyHo8JPEZkk6BqeW8yI+B8qIOnY8=; b=p7yqdGs5uBAGBs r8PGaDeawxH7gRgV4ovy6mMORRH0mZF6D0ztgyU67/hYMgNNNs9CuoEuSY1f2xao0IWfwJyOX6P/D VXsq+2WSNWCQdanDmhnUUQ9hp99CouIAH8yP3FQZb1UmjjPsCErto198jJ83lwyfyC8iKqZi4K/z/ 1WL6CBq+kMvlq5a2kUd/GnElARA6IefwdRlOZ1BjWP8mxxJZezQwHdyeCIlxMrCmfRhJjVH/BosbI 4KB32JBd4kJfq2NNDlDj4pg/HJdw9uICmZKfVwYfSqu+SV9/8fuczRKT+4vJqAVKB+4RHE8QgnTKt wdgEVY578J1765LRO2lA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1locNz-006jMO-Q8; Thu, 03 Jun 2021 01:43:03 +0000 Received: from gate.crashing.org ([63.228.1.57]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1locNv-006jM0-TT for linux-arm-kernel@lists.infradead.org; Thu, 03 Jun 2021 01:43:01 +0000 Received: from ip6-localhost (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 1531fl6U017081; Wed, 2 Jun 2021 20:41:48 -0500 Message-ID: <03af6cf4f263f9de4b7dbcf16e8a1c4962347191.camel@kernel.crashing.org> Subject: Re: RNDR/SS vs. SMCCC From: Benjamin Herrenschmidt To: Andre Przywara Cc: Ard Biesheuvel , Mark Brown , Will Deacon , "Saidi, Ali" , Linux ARM Date: Thu, 03 Jun 2021 11:41:47 +1000 In-Reply-To: <20210603011922.1d0e9249@slackpad.fritz.box> References: <7d5697f3994fc1f9cf39d332525269056e3649b3.camel@kernel.crashing.org> <0339748b54e2faeddeec8d50e32a6c6ff4e8b3b7.camel@kernel.crashing.org> <20210531020235.6e4ea946@slackpad.fritz.box> <2ae9253c6f5753c13a7ed755ab0c67316c06d9b0.camel@kernel.crashing.org> <20210603011922.1d0e9249@slackpad.fritz.box> User-Agent: Evolution 3.36.4-0ubuntu1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210602_184300_212194_B92B1794 X-CRM114-Status: GOOD ( 14.20 ) 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 Thu, 2021-06-03 at 01:19 +0100, Andre Przywara wrote: > > You mean like this? > https://gitlab.arm.com/linux-arm/linux-ap/-/commit/87e3722f437f9c3f09397e0e9812e6509c94786a Yes. We have a similar one in Amazon Linux which I think Ali submitted a while back but never went upstream. > This is not reviewed nor widely tested, but I used it for assessing the > quality of the SMCCC provided numbers on the Juno board using rngtest. > I think one problem was that this opens the SMCCC to userland, so the > entropy could be depleted from there (again under the assumption that > this is really a problem in practice). IMHO, userland can always adjust permission to /dev/hwrng if it wishes to do so... > I would be interested to hear opinions on this. The issue is with things like FIPS certification (and other such horrors) where I believe /dev/random is much harder to deal with since it mixes multiple entropy sources. Cheers, Ben. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel