Received: by 2002:a25:e74b:0:0:0:0:0 with SMTP id e72csp1835279ybh; Fri, 17 Jul 2020 02:26:18 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwvooBBEoDhI2Pf443ol8q/FZHS85uXv3NSalYpiyU1J3+4Rbibh73p59cZAhF1oOIxwkhg X-Received: by 2002:a17:906:66d0:: with SMTP id k16mr7974010ejp.293.1594977978054; Fri, 17 Jul 2020 02:26:18 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1594977978; cv=none; d=google.com; s=arc-20160816; b=Vx2Ay9qpvxa/+swrFtT4jnR89fgDhzo6Syj7EZ/OqL5J8yE4WGjal20ewjpMhNzFuP qQEkvb2y7RHa0+IavR0pYXzhTFcsZPxlFhPJ8ht+qu6ZVpnJ7R2zPoKs6aTWD75yHHu1 JPId9cqR3vL1DqwtSx5NvH+PWzBEzPZL5bcPglA8L+x959xeVE+u47w2CAHEsMmWI2IR /l3GCrNFkoWym6kaOq2A557NcryRz+GQvoqkAStG1TH0LeyLdbq98dXI1LwI4JbWUvc5 eYPmlam2WyOYiWR5sSvznY5ApXrS5pOcVLy4gOUO276xtm+Gfys1PjsGvtrb5HwQqSs+ bJDQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :dkim-signature; bh=oh4+QZoZC7XJ5liIvD/prbetozs/+rcdlSei8EeQx8I=; b=DWXPoE5dFYfPQEnWD0fAskKGA9ugS0S/Oia+CZaaemvVf9gK/qT/3tpvkFQQ3QniQq yjpnFVKCZ0Ob6W5nX3k36Rq0WRrDmFk5C8bIzEdGHKkuAC8Otdt6p7cFE2Fcy4WUIWjP RjeRR6Ohs2YdlYBEGAXIpgociEZKqMqF8igza6R0nXQPjT62Ag0IxB8Ic8IZ6oiZSzLZ YwBTIWYnMRUGbbYVsfpOeKgctxQ6kdXiniO+PEVvwUHeLUb1BMgZq7FOythLzgKgcIwu zItfv4Eb2GSOB9Hox4/He6muJRvl/g9aLbuXSN/zHQ3+Pu2fHVKmmjvYtpH31fzYXy5P NA3Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@infradead.org header.s=merlin.20170209 header.b=kazs8KzU; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id l13si5084136eds.603.2020.07.17.02.25.55; Fri, 17 Jul 2020 02:26:18 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=fail header.i=@infradead.org header.s=merlin.20170209 header.b=kazs8KzU; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726528AbgGQJZU (ORCPT + 99 others); Fri, 17 Jul 2020 05:25:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725912AbgGQJZT (ORCPT ); Fri, 17 Jul 2020 05:25:19 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25830C061755; Fri, 17 Jul 2020 02:25:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=oh4+QZoZC7XJ5liIvD/prbetozs/+rcdlSei8EeQx8I=; b=kazs8KzUqKOCO/2D6mprbyvEnU +fzslg8lr95LXVXM9aFdR5oVu7YU+jtZjZuUuNhtdMoijq35pApqNb0Kjpu2+qVjYJPMxBkMxwxwt zJhrNYgoG+hopYMkGXql6VsXOH/lcfSxf6ew9w8rrvlgWZWbac4aHyF3rLfDTz9Z9EaOC5qqudxmp MPUw2W8cUivp9Wp2v/EKMhTIHSccGcg5LfOOnbnhGaWNlBaW4Nt73aFJHO/KOx+DjkatJQ183jtX+ +ShtbR2b2ELtr1q+XxcZs8EPUhEs/rKmpIBEOk0TS2IxU4449Zsd/jtbWwQvb1sB85UrR0QJJ9Ss7 A65td5HQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jwMc8-00048L-Pk; Fri, 17 Jul 2020 09:25:08 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 6906F300130; Fri, 17 Jul 2020 11:25:07 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 5316B29CF6F53; Fri, 17 Jul 2020 11:25:07 +0200 (CEST) Date: Fri, 17 Jul 2020 11:25:07 +0200 From: Peter Zijlstra To: ira.weiny@intel.com Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , x86@kernel.org, Dave Hansen , Dan Williams , Vishal Verma , Andrew Morton , Fenghua Yu , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH RFC V2 16/17] [dax|pmem]: Enable stray write protection Message-ID: <20200717092507.GE10769@hirez.programming.kicks-ass.net> References: <20200717072056.73134-1-ira.weiny@intel.com> <20200717072056.73134-17-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200717072056.73134-17-ira.weiny@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 17, 2020 at 12:20:55AM -0700, ira.weiny@intel.com wrote: > From: Ira Weiny > > Protecting against stray writes is particularly important for PMEM > because, unlike writes to anonymous memory, writes to PMEM persists > across a reboot. Thus data corruption could result in permanent loss of > data. Therefore, there is no option presented to the user. > > Enable stray write protection by setting the flag in pgmap which > requests it. Note if Zone Device Access Protection not be supported > this flag will have no affect. The actual implementation is stray-access-protection, as noted ealier. This inconsisteny is throughout.