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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 75B9AC433DF for ; Sat, 17 Oct 2020 05:42:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CBE220791 for ; Sat, 17 Oct 2020 05:42:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436620AbgJQFmR (ORCPT ); Sat, 17 Oct 2020 01:42:17 -0400 Received: from mga12.intel.com ([192.55.52.136]:56627 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408934AbgJQFmR (ORCPT ); Sat, 17 Oct 2020 01:42:17 -0400 IronPort-SDR: 4knH7JxomiV86CjX5h0Kj2bf2SeKDFDrl1ycf5JYrYMXI4yuTTknG3qIjv8lKBDoN3p7pLqEa/ 6MTSaYJPrVSg== X-IronPort-AV: E=McAfee;i="6000,8403,9776"; a="146052110" X-IronPort-AV: E=Sophos;i="5.77,385,1596524400"; d="scan'208";a="146052110" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Oct 2020 22:42:16 -0700 IronPort-SDR: bloDPZ1mHCCMDkSL4HTubqN5FZT0XoM6+FUXgp3YTonyMsQFc3Ur7Lotbw2ij0kO5hWgIJ5cfw HGUQxgmHfd2w== X-IronPort-AV: E=Sophos;i="5.77,385,1596524400"; d="scan'208";a="522528942" 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; 16 Oct 2020 22:42:16 -0700 Date: Fri, 16 Oct 2020 22:42:16 -0700 From: Ira Weiny To: Peter Zijlstra Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Fenghua Yu , x86@kernel.org, Dave Hansen , Dan Williams , Andrew Morton , 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 V3 5/9] x86/pks: Add PKS kernel API Message-ID: <20201017054216.GB3702775@iweiny-DESK2.sc.intel.com> References: <20201009194258.3207172-1-ira.weiny@intel.com> <20201009194258.3207172-6-ira.weiny@intel.com> <20201016110747.GM2611@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201016110747.GM2611@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.11.1 (2018-12-01) Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Fri, Oct 16, 2020 at 01:07:47PM +0200, Peter Zijlstra wrote: > On Fri, Oct 09, 2020 at 12:42:54PM -0700, ira.weiny@intel.com wrote: > > +static inline void pks_update_protection(int pkey, unsigned long protection) > > +{ > > + current->thread.saved_pkrs = update_pkey_val(current->thread.saved_pkrs, > > + pkey, protection); > > + preempt_disable(); > > + write_pkrs(current->thread.saved_pkrs); > > + preempt_enable(); > > +} > > write_pkrs() already disables preemption itself. Wrapping it in yet > another layer is useless. I was thinking the update to saved_pkrs needed this protection as well and that was to be included in the preemption disable. But that too is incorrect. I've removed this preemption disable. Thanks, Ira