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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 F3D2AC3A5A1 for ; Thu, 22 Aug 2019 14:45:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C837C233A1 for ; Thu, 22 Aug 2019 14:45:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732378AbfHVOpX (ORCPT ); Thu, 22 Aug 2019 10:45:23 -0400 Received: from mga11.intel.com ([192.55.52.93]:61825 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731146AbfHVOpX (ORCPT ); Thu, 22 Aug 2019 10:45:23 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Aug 2019 07:45:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,417,1559545200"; d="scan'208";a="208191565" Received: from greathea-mobl2.ger.corp.intel.com ([10.252.39.37]) by fmsmga002.fm.intel.com with ESMTP; 22 Aug 2019 07:45:21 -0700 Message-ID: <53356fc2b00d322f599a92a07d1ce83a66dc4df4.camel@linux.intel.com> Subject: Re: [PATCH 1/2] x86/sgx: Remove duplicate check for entry->epc_page in sgx_encl_load_page() From: Jarkko Sakkinen To: Sean Christopherson Cc: linux-sgx@vger.kernel.org Date: Thu, 22 Aug 2019 17:45:20 +0300 In-Reply-To: <20190822003358.GO29345@linux.intel.com> References: <20190821232902.29476-1-jarkko.sakkinen@linux.intel.com> <20190821232902.29476-2-jarkko.sakkinen@linux.intel.com> <20190822003358.GO29345@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.32.2-1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Wed, 2019-08-21 at 17:33 -0700, Sean Christopherson wrote: > On Thu, Aug 22, 2019 at 02:29:01AM +0300, Jarkko Sakkinen wrote: > > The existence of the page is checked first hand for legit race > > conditions (either two or more concurrent threads running the #PF > > handler or the reclaimer has taken over the page): > > > > /* Page is already resident in the EPC. */ > > if (entry->epc_page) { > > if (entry->desc & SGX_ENCL_PAGE_RECLAIMED) > > return ERR_PTR(-EBUSY); > > > > return entry; > > } > > > > After that the existence is a checked as a condition for ELDU. > > > > This commit removes the redundant check. > > > > Cc: Sean Christopherson > > Signed-off-by: Jarkko Sakkinen > > --- > > Ha, I remember seeing this a while back and completely forgot about it. > > Reviewed-by: Sean Christopherson [I guess for this ack-by would be appropriate as they are not mainline patches] Thanks Sean. These kind of regression are almost unavoidable because of heavy rebasing... /Jarkko