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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 E8B45C433B4 for ; Wed, 5 May 2021 02:03:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 76F30610E6 for ; Wed, 5 May 2021 02:03:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 76F30610E6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0163C8D0063; Tue, 4 May 2021 22:03:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F2EFD8D003B; Tue, 4 May 2021 22:03:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DF6C78D0063; Tue, 4 May 2021 22:03:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0150.hostedemail.com [216.40.44.150]) by kanga.kvack.org (Postfix) with ESMTP id C4E048D003B for ; Tue, 4 May 2021 22:03:58 -0400 (EDT) Received: from smtpin38.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 8AE223D15 for ; Wed, 5 May 2021 02:03:58 +0000 (UTC) X-FDA: 78105531756.38.CC92406 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by imf19.hostedemail.com (Postfix) with ESMTP id 76FC490009F1 for ; Wed, 5 May 2021 02:03:24 +0000 (UTC) IronPort-SDR: mbX7JRfCn09jBQ/PfwY/7G+w3hBUsdWNYvfgI/k622tgjzWBoGXlB104oXS5xdNmSkMkgrKrII /MUPu3l18GjQ== X-IronPort-AV: E=McAfee;i="6200,9189,9974"; a="197734164" X-IronPort-AV: E=Sophos;i="5.82,273,1613462400"; d="scan'208";a="197734164" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 May 2021 19:03:54 -0700 IronPort-SDR: qmaz3lgwLJOIwgqsyrLKcWH5vSggMksDOP+oksXCm5BbW9SHf3O50ZGo68GJ2/kJ9Eakkp/MM5 +XVO/SvgJHAw== X-IronPort-AV: E=Sophos;i="5.82,273,1613462400"; d="scan'208";a="621741505" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 May 2021 19:03:53 -0700 Date: Tue, 4 May 2021 19:03:53 -0700 From: Ira Weiny To: Rick Edgecombe Cc: dave.hansen@intel.com, luto@kernel.org, peterz@infradead.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, linux-hardening@vger.kernel.org, kernel-hardening@lists.openwall.com, rppt@kernel.org, dan.j.williams@intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC 0/9] PKS write protected page tables Message-ID: <20210505020353.GE1904484@iweiny-DESK2.sc.intel.com> References: <20210505003032.489164-1-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210505003032.489164-1-rick.p.edgecombe@intel.com> User-Agent: Mutt/1.11.1 (2018-12-01) Authentication-Results: imf19.hostedemail.com; dkim=none; spf=none (imf19.hostedemail.com: domain of ira.weiny@intel.com has no SPF policy when checking 192.55.52.115) smtp.mailfrom=ira.weiny@intel.com; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none) X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 76FC490009F1 X-Stat-Signature: gaiquktjfp37jnho5pm9bztnhgr3y9x4 Received-SPF: none (intel.com>: No applicable sender policy available) receiver=imf19; identity=mailfrom; envelope-from=""; helo=mga14.intel.com; client-ip=192.55.52.115 X-HE-DKIM-Result: none/none X-HE-Tag: 1620180204-639514 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000013, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, May 04, 2021 at 05:30:23PM -0700, Rick Edgecombe wrote: >=20 > This is based on V6 [1] of the core PKS infrastructure patches. PKS=20 > infrastructure follow-on=E2=80=99s are planned to enable keys to be set= to the same=20 > permissions globally. Since this usage needs a key to be set globally=20 > read-only by default, a small temporary solution is hacked up in patch = 8. Long=20 > term, PKS protected page tables would use a better and more generic sol= ution=20 > to achieve this. Before you send this out I've been thinking about this more and I think I= would prefer you not call this 'globally' setting the key. Because you don't r= eally want to be able to update the key globally like I originally suggested fo= r kmap(). What is required is to set a different default for the key which= gets used by all threads by 'default'. What is really missing is how to get the default changed after it may hav= e been used by some threads... thus the 'global' nature... Perhaps I am pickin= g nits here but I think it may go over better with Thomas and the maintainers. = Or maybe not... :-) Would it be too much trouble to call this a 'default' change? Because th= at is really what you implement? Ira