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,UNPARSEABLE_RELAY, 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 17428C433E0 for ; Sun, 24 Jan 2021 06:35:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD3FC22C7E for ; Sun, 24 Jan 2021 06:35:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726599AbhAXGfE (ORCPT ); Sun, 24 Jan 2021 01:35:04 -0500 Received: from out30-57.freemail.mail.aliyun.com ([115.124.30.57]:40476 "EHLO out30-57.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726398AbhAXGfE (ORCPT ); Sun, 24 Jan 2021 01:35:04 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R551e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04400;MF=tianjia.zhang@linux.alibaba.com;NM=1;PH=DS;RN=10;SR=0;TI=SMTPD_---0UMg2q4g_1611470034; Received: from 30.25.221.71(mailfrom:tianjia.zhang@linux.alibaba.com fp:SMTPD_---0UMg2q4g_1611470034) by smtp.aliyun-inc.com(127.0.0.1); Sun, 24 Jan 2021 14:33:55 +0800 Subject: Re: [PATCH v2] x86/sgx: Remove redundant if conditions in sgx_encl_create To: Sean Christopherson Cc: Jarkko Sakkinen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org, Jia Zhang References: <20210120035328.19868-1-tianjia.zhang@linux.alibaba.com> From: Tianjia Zhang Message-ID: <95913686-be5f-85e5-0cc2-91b2a100e16e@linux.alibaba.com> Date: Sun, 24 Jan 2021 14:33:53 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On 1/21/21 1:47 AM, Sean Christopherson wrote: > On Wed, Jan 20, 2021, Tianjia Zhang wrote: >> In this scenario, there is no case where va_page is NULL, and >> the error has been checked. The if condition statement here is >> redundant, so remove the condition detection. >> >> Reported-by: Jia Zhang >> Suggested-by: Sean Christopherson >> Signed-off-by: Tianjia Zhang >> --- >> arch/x86/kernel/cpu/sgx/ioctl.c | 9 ++++++--- >> 1 file changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c >> index 1c6ecf9fbeff..efad2fb61c76 100644 >> --- a/arch/x86/kernel/cpu/sgx/ioctl.c >> +++ b/arch/x86/kernel/cpu/sgx/ioctl.c >> @@ -66,9 +66,12 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) >> va_page = sgx_encl_grow(encl); >> if (IS_ERR(va_page)) >> return PTR_ERR(va_page); >> - else if (va_page) >> - list_add(&va_page->list, &encl->va_pages); >> - /* else the tail page of the VA page list had free slots. */ >> + >> + if (WARN_ONCE(!va_page, >> + "the tail page of the VA page list had free slots\n")) > > IMO it's worth trimming down the message to keep this on a single line. The > newline isn't necessary, and this code expects a completely empty list, e.g. it > can be reworded to something like: > > if (WARN_ONCE(!va_page, "non-empty VA page list before ECREATE")) > Thanks for your suggestion, I have resubmitted a set of patches. Best regards, Tianjia