Received: by 10.192.165.156 with SMTP id m28csp2219881imm; Sat, 14 Apr 2018 17:42:53 -0700 (PDT) X-Google-Smtp-Source: AIpwx4+2/pDf9zVV7QemdNhKsO8v2Cdss0LfiEhf3SDqgSO/LRJkIvmK2lxVT7fLvupkSrscpQxg X-Received: by 2002:a17:902:9a8b:: with SMTP id w11-v6mr6465460plp.75.1523752973893; Sat, 14 Apr 2018 17:42:53 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1523752973; cv=none; d=google.com; s=arc-20160816; b=azb69V1Mp98MKHIW+jsHbLlin/1FAEeeqXK1/57QLrdFjrt9SBZc4ZB5+CVTaGnQLD BFz5KM8V4mL2pN/Mz5DPz9nv3eH722F4Xw9W6WtfM66elqGWcJOK9ThwD58+0ABBj8zt jIJlbqBfTCMyQwv7+HsqYvMZj43e5Mgd4dt5VMznhaCZoKlDjVxAm/AF8Defe8vG3uRC k/q3DOy+v57KUz94QVrHRtAbpMu0q76LCPWtcl/kCV0xarWgJuU00J8gIVQ7c1nYB4/V TXYYLHNYm7gw9NvVTJ4Py9bxRWNbv5VDpNX26tvhQ8lFEVLZFUmhLeEioAYZvj83yd4F eaBQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:to :from:date:dkim-signature:arc-authentication-results; bh=ApirGB+quOABvXBwmTecHWaJ8Ybtdnp3N1KZ9znG4lM=; b=iED2pIQePhzrSaT/shEBLojNwHnHGo0vXNuCYqn09VkU4F1eFjAswQ2gCTq32wytX9 TtHubDynjjfJeenAJSIZLLZYkFP6Dp5/R702KrYaHsU1Whc8ocTWhIsNHDIud944dkVs OXg4CwCZqBlWzwGzLhHe4f/rhgsNPGPM5ufmYc9IyQPy5ZWEFM70rmUzL+9TmMeuBAef 4FX6M08YDhm3nf1iK5tqRVbXS+AxECr6hyOmBPvhJCPAQJ1CzTA0SDzvEA/eVI8XCY9Z puyavWgR1C3ZIOdRFc/oO5mJimXGFWC48aXBENiz7MznhJVCJNfihUdzSiiaxCpj4i7I mLGg== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@infradead.org header.s=bombadil.20170209 header.b=H54t2wmw; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id r3-v6si5704469pli.324.2018.04.14.17.42.40; Sat, 14 Apr 2018 17:42:53 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@infradead.org header.s=bombadil.20170209 header.b=H54t2wmw; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752137AbeDOAlg (ORCPT + 99 others); Sat, 14 Apr 2018 20:41:36 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:35822 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751270AbeDOAlg (ORCPT ); Sat, 14 Apr 2018 20:41:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:To:From:Date:Sender:Reply-To:Cc: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=ApirGB+quOABvXBwmTecHWaJ8Ybtdnp3N1KZ9znG4lM=; b=H54t2wmwtCSIvcOTWf7sbR7WB nGjJHi4eJYgj0piv9wO5G2snumjNxiNEPc+pX4RkwcWgYCtBlEEZDaGhmJXBHpVUrzv8J2p5V52Fu hzIGKvA8unij4sHcTv1yV9ng4X5aCFiBHmeWyDUAFPE/vhb5vfHYP1DUEKAuHhZ6BNTm62i/bAOWl tcym+PJTEYMOws6FQDv3dcrsBo3Aheboby2M53/shyxUrqoQYchGca40qa7L58KPKMqyKtWzipq26 +MT2dHEvYnR0wH1fK2Zyq6Rgl8rYyye3hfOwQaikpMsaa3cY5JN7p9TKNath4Z3hkjUVhysJmcD7h nVD39SYog==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1f7Vja-0008FH-Oa; Sun, 15 Apr 2018 00:41:34 +0000 Date: Sat, 14 Apr 2018 17:41:34 -0700 From: Matthew Wilcox To: "Theodore Y. Ts'o" , Alexey Dobriyan , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: repeatable boot randomness inside KVM guest Message-ID: <20180415004134.GB15294@bombadil.infradead.org> References: <20180414195921.GA10437@avx2> <20180414224419.GA21830@thunk.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180414224419.GA21830@thunk.org> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Apr 14, 2018 at 06:44:19PM -0400, Theodore Y. Ts'o wrote: > What needs to happen is freelist should get randomized much later in > the boot sequence. Doing it later will require locking; I don't know > enough about the slab/slub code to know whether the slab_mutex would > be sufficient, or some other lock might need to be added. Could we have the bootloader pass in some initial randomness?