From patchwork Mon Feb 1 13:26:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "tianjia.zhang" X-Patchwork-Id: 374413 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, USER_AGENT_GIT autolearn=unavailable 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 DC3CBC433E6 for ; Mon, 1 Feb 2021 13:28:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A75E464E9A for ; Mon, 1 Feb 2021 13:28:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232005AbhBAN23 (ORCPT ); Mon, 1 Feb 2021 08:28:29 -0500 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:60737 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231594AbhBAN2L (ORCPT ); Mon, 1 Feb 2021 08:28:11 -0500 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R161e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=alimailimapcm10staff010182156082; MF=tianjia.zhang@linux.alibaba.com; NM=1; PH=DS; RN=13; SR=0; TI=SMTPD_---0UNbCiom_1612186013; Received: from localhost(mailfrom:tianjia.zhang@linux.alibaba.com fp:SMTPD_---0UNbCiom_1612186013) by smtp.aliyun-inc.com(127.0.0.1); Mon, 01 Feb 2021 21:26:54 +0800 From: Tianjia Zhang To: Jarkko Sakkinen , 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 Cc: Tianjia Zhang Subject: [PATCH v4 2/5] x86/sgx: Reduce the locking range in sgx_sanitize_section() Date: Mon, 1 Feb 2021 21:26:50 +0800 Message-Id: <20210201132653.35690-3-tianjia.zhang@linux.alibaba.com> X-Mailer: git-send-email 2.19.1.3.ge56e4f7 In-Reply-To: <20210201132653.35690-1-tianjia.zhang@linux.alibaba.com> References: <20210201132653.35690-1-tianjia.zhang@linux.alibaba.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org The spin lock of sgx_epc_section only locks the page_list. The EREMOVE operation and init_laundry_list is not necessary in the protection range of the spin lock. This patch reduces the lock range of the spin lock in the function sgx_sanitize_section() and only protects the operation of the page_list. Suggested-by: Sean Christopherson Signed-off-by: Tianjia Zhang --- arch/x86/kernel/cpu/sgx/main.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index c519fc5f6948..4465912174fd 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -41,20 +41,17 @@ static void sgx_sanitize_section(struct sgx_epc_section *section) if (kthread_should_stop()) return; - /* needed for access to ->page_list: */ - spin_lock(§ion->lock); - page = list_first_entry(§ion->init_laundry_list, struct sgx_epc_page, list); ret = __eremove(sgx_get_epc_virt_addr(page)); - if (!ret) + if (!ret) { + spin_lock(§ion->lock); list_move(&page->list, §ion->page_list); - else + spin_unlock(§ion->lock); + } else list_move_tail(&page->list, &dirty); - spin_unlock(§ion->lock); - cond_resched(); }