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=-9.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 94383C4363D for ; Mon, 5 Oct 2020 03:27:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A1FF207BC for ; Mon, 5 Oct 2020 03:27:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725852AbgJED1u (ORCPT ); Sun, 4 Oct 2020 23:27:50 -0400 Received: from mga07.intel.com ([134.134.136.100]:56753 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725846AbgJED1u (ORCPT ); Sun, 4 Oct 2020 23:27:50 -0400 IronPort-SDR: BG29/vvyhHxYm5WtLbCQRXYFdJqU+ps8OjOcfl6AAHEaWU/VdFrnCbpYGiAuf3aQV5TmdooGMj 5M/2TYBhowPQ== X-IronPort-AV: E=McAfee;i="6000,8403,9764"; a="227458659" X-IronPort-AV: E=Sophos;i="5.77,337,1596524400"; d="scan'208";a="227458659" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Oct 2020 20:27:47 -0700 IronPort-SDR: ECfYkgU/8L5YniXt3ECya8pYDvuKF4eU5HtcHGgXSTggz15fcFb1eu/slJhNw4nbNV71PUoe+T BfYTqO114jMg== X-IronPort-AV: E=Sophos;i="5.77,337,1596524400"; d="scan'208";a="523296806" Received: from hhuan26-mobl1.amr.corp.intel.com (HELO mqcpg7oapc828.gar.corp.intel.com) ([10.255.36.21]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-SHA; 04 Oct 2020 20:27:46 -0700 Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes To: linux-sgx@vger.kernel.org, "Jarkko Sakkinen" Cc: "Sean Christopherson" , "Jethro Beekman" , "Matthew Wilcox" , "Dave Hansen" Subject: Re: [PATCH] x86/sgx: Fix sgx_encl_may_map locking References: <20201005004120.105849-1-jarkko.sakkinen@linux.intel.com> Date: Sun, 04 Oct 2020 22:27:43 -0500 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: "Haitao Huang" Organization: Intel Corp Message-ID: In-Reply-To: <20201005004120.105849-1-jarkko.sakkinen@linux.intel.com> User-Agent: Opera Mail/1.0 (Win32) Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Sun, 04 Oct 2020 19:41:20 -0500, Jarkko Sakkinen wrote: > Fix the issue further discussed in: > > 1. > https://lore.kernel.org/linux-sgx/op.0rwbv916wjvjmi@mqcpg7oapc828.gar.corp.intel.com/ > 2. > https://lore.kernel.org/linux-sgx/20201003195440.GD20115@casper.infradead.org/ > > Reported-by: Haitao Huang > Cc: Sean Christopherson > Cc: Jethro Beekman > Cc: Matthew Wilcox > Cc: Dave Hansen > Signed-off-by: Jarkko Sakkinen > --- > arch/x86/kernel/cpu/sgx/encl.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/kernel/cpu/sgx/encl.c > b/arch/x86/kernel/cpu/sgx/encl.c > index ae45f8f0951e..a225e96c7a39 100644 > --- a/arch/x86/kernel/cpu/sgx/encl.c > +++ b/arch/x86/kernel/cpu/sgx/encl.c > @@ -304,11 +304,10 @@ int sgx_encl_may_map(struct sgx_encl *encl, > unsigned long start, > unsigned long end, unsigned long vm_flags) > { > unsigned long vm_prot_bits = vm_flags & (VM_READ | VM_WRITE | VM_EXEC); > - unsigned long idx_start = PFN_DOWN(start); > - unsigned long idx_end = PFN_DOWN(end - 1); > + unsigned long start_i = PFN_DOWN(start); > + unsigned long end_i = PFN_DOWN(end - 1); > struct sgx_encl_page *page; > - > - XA_STATE(xas, &encl->page_array, idx_start); > + int i; > /* > * Disallow READ_IMPLIES_EXEC tasks as their VMA permissions might > @@ -317,9 +316,14 @@ int sgx_encl_may_map(struct sgx_encl *encl, > unsigned long start, > if (current->personality & READ_IMPLIES_EXEC) > return -EACCES; > - xas_for_each(&xas, page, idx_end) > + for (i = start_i; i <= end_i; i++) { > + mutex_lock(&encl->lock); > + page = xa_load(&encl->page_array, i); > + mutex_unlock(&encl->lock); > + > if (!page || (~page->vm_max_prot_bits & vm_prot_bits)) > return -EACCES; > + } > return 0; > } Works with no PROVE_LOCKING complaints. Haitao