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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 E4AB7C433E6 for ; Tue, 26 Jan 2021 15:41:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B332121D42 for ; Tue, 26 Jan 2021 15:41:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389107AbhAZPlj (ORCPT ); Tue, 26 Jan 2021 10:41:39 -0500 Received: from mga06.intel.com ([134.134.136.31]:59486 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392365AbhAZPkM (ORCPT ); Tue, 26 Jan 2021 10:40:12 -0500 IronPort-SDR: /wZY3hO8ruwtY9mp2k8U4GvUfiUgZsV6bAwpfRQ8nga9ZWspsZshutu6D4gBJkmhb3JAMMHBob ZQ3yiqNC7eMA== X-IronPort-AV: E=McAfee;i="6000,8403,9876"; a="241448361" X-IronPort-AV: E=Sophos;i="5.79,375,1602572400"; d="scan'208";a="241448361" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2021 07:39:31 -0800 IronPort-SDR: 7bM+3D0caAg+WzEbRwkav4Sm8LT7rWTeerVcjpdt0m1aBORg+6RjJSSW/FUO8oCK9+8PGtc8zi vXRK+isJlTng== X-IronPort-AV: E=Sophos;i="5.79,375,1602572400"; d="scan'208";a="369138873" Received: from ekfraser-mobl1.amr.corp.intel.com (HELO [10.209.173.94]) ([10.209.173.94]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2021 07:39:30 -0800 Subject: Re: [RFC PATCH v3 03/27] x86/sgx: Remove a warn from sgx_free_epc_page() To: Kai Huang , linux-sgx@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org Cc: seanjc@google.com, jarkko@kernel.org, luto@kernel.org, haitao.huang@intel.com, pbonzini@redhat.com, bp@alien8.de, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com References: <36e999dce8a1a4efb8ca69c9a6fbe3fa63305e08.1611634586.git.kai.huang@intel.com> From: Dave Hansen Autocrypt: addr=dave.hansen@intel.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <36e999dce8a1a4efb8ca69c9a6fbe3fa63305e08.1611634586.git.kai.huang@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On 1/26/21 1:30 AM, Kai Huang wrote: > Remove SGX_EPC_PAGE_RECLAIMER_TRACKED check and warning. This cannot > happen, as enclave pages are freed only at the time when encl->refcount > triggers, i.e. when both VFS and the page reclaimer have given up on > their references. > > Signed-off-by: Jarkko Sakkinen > Signed-off-by: Kai Huang > --- > arch/x86/kernel/cpu/sgx/main.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c > index 8df81a3ed945..f330abdb5bb1 100644 > --- a/arch/x86/kernel/cpu/sgx/main.c > +++ b/arch/x86/kernel/cpu/sgx/main.c > @@ -605,8 +605,6 @@ void sgx_free_epc_page(struct sgx_epc_page *page) > struct sgx_epc_section *section = &sgx_epc_sections[page->section]; > int ret; > > - WARN_ON_ONCE(page->flags & SGX_EPC_PAGE_RECLAIMER_TRACKED); I'm all for cleaning up silly, useless warnings. But, don't we usually put warnings in for things that we don't expect to be able to happen? In other words, I'm fine with removing this if it hasn't been a valuable warning and we don't expect it to become a valuable warning. But, the changelog doesn't say that. It also doesn't explain what this patch is doing in this series. Why is this her?