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=-15.2 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 20FD8C433E9 for ; Wed, 24 Feb 2021 09:32:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D73EC64F00 for ; Wed, 24 Feb 2021 09:32:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234635AbhBXJcV (ORCPT ); Wed, 24 Feb 2021 04:32:21 -0500 Received: from out4436.biz.mail.alibaba.com ([47.88.44.36]:57553 "EHLO out4436.biz.mail.alibaba.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232166AbhBXJcD (ORCPT ); Wed, 24 Feb 2021 04:32:03 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R981e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04395;MF=tianjia.zhang@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0UPS1eWx_1614159062; Received: from B-455UMD6M-2027.local(mailfrom:tianjia.zhang@linux.alibaba.com fp:SMTPD_---0UPS1eWx_1614159062) by smtp.aliyun-inc.com(127.0.0.1); Wed, 24 Feb 2021 17:31:03 +0800 Subject: Re: [PATCH v5 3/3] x86/sgx: Remove redundant if conditions in sgx_encl_create To: Jarkko Sakkinen Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Sean Christopherson , Shuah Khan , x86@kernel.org, linux-sgx@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Jia Zhang References: <20210216033133.79543-1-tianjia.zhang@linux.alibaba.com> <20210216033133.79543-4-tianjia.zhang@linux.alibaba.com> From: Tianjia Zhang Message-ID: <04aea989-13b3-1046-b8cd-86abb27f09c0@linux.alibaba.com> Date: Wed, 24 Feb 2021 17:31:02 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 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-kselftest@vger.kernel.org On 2/16/21 4:29 PM, Jarkko Sakkinen wrote: > On Tue, Feb 16, 2021 at 11:31:33AM +0800, 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. >> >> Signed-off-by: Tianjia Zhang >> Acked-by: Jarkko Sakkinen >> --- >> arch/x86/kernel/cpu/sgx/ioctl.c | 7 ++++--- >> 1 file changed, 4 insertions(+), 3 deletions(-) >> >> diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c >> index 1c6ecf9fbeff..719c21cca569 100644 >> --- a/arch/x86/kernel/cpu/sgx/ioctl.c >> +++ b/arch/x86/kernel/cpu/sgx/ioctl.c >> @@ -66,9 +66,10 @@ 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 (!va_page) >> + return -EIO; > > Why this check? > The value of va_page may be a negative error value, it may be NULL, or it may be a valid pointer, so check this return value. Tianjia >> + >> + list_add(&va_page->list, &encl->va_pages); >> >> /* The extra page goes to SECS. */ >> encl_size = secs->size + PAGE_SIZE; >> -- >> 2.19.1.3.ge56e4f7 >> >> > > /Jarkko >