From patchwork Tue Jan 10 20:55:58 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 9508515 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5AE5360762 for ; Tue, 10 Jan 2017 20:56:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 471912857B for ; Tue, 10 Jan 2017 20:56:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 39BB1285B9; Tue, 10 Jan 2017 20:56:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D72A9285A9 for ; Tue, 10 Jan 2017 20:56:22 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 7AAC781B24 for ; Tue, 10 Jan 2017 12:56:22 -0800 (PST) X-Original-To: intel-sgx-kernel-dev@lists.01.org Delivered-To: intel-sgx-kernel-dev@lists.01.org Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 7791B81999 for ; Tue, 10 Jan 2017 12:56:21 -0800 (PST) Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga101.jf.intel.com with ESMTP; 10 Jan 2017 12:56:04 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,344,1477983600"; d="scan'208";a="51736959" Received: from sjchrist-ts.jf.intel.com ([10.54.74.20]) by fmsmga005.fm.intel.com with ESMTP; 10 Jan 2017 12:56:04 -0800 From: Sean Christopherson To: intel-sgx-kernel-dev@lists.01.org Date: Tue, 10 Jan 2017 12:55:58 -0800 Message-Id: <1484081758-20302-5-git-send-email-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1484081758-20302-1-git-send-email-sean.j.christopherson@intel.com> References: <1484081758-20302-1-git-send-email-sean.j.christopherson@intel.com> Subject: [intel-sgx-kernel-dev] [PATCH 4/4] intel_sgx: Kill enclave if vm_insert_pfn fails X-BeenThere: intel-sgx-kernel-dev@lists.01.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Project: Intel® Software Guard Extensions for Linux*: https://01.org/intel-software-guard-extensions" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-sgx-kernel-dev-bounces@lists.01.org Sender: "intel-sgx-kernel-dev" X-Virus-Scanned: ClamAV using ClamSMTP Log a warning and kill the enclave if vm_insert_pfn fails while handling a page fault. Removing the page from the EPC via EREMOVE can result in kernel panics as EREMOVE will fail if there are active threads in the enclave. Retrying vm_insert_pfn at a later date won't succeed as calls to vm_insert_pfn are protected by encl->lock, i.e. there are no valid scenarios where EBUSY can be returned, failure indicates a driver bug. Signed-off-by: Sean Christopherson --- drivers/platform/x86/intel_sgx_vma.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/platform/x86/intel_sgx_vma.c b/drivers/platform/x86/intel_sgx_vma.c index e670405..67a51ee 100644 --- a/drivers/platform/x86/intel_sgx_vma.c +++ b/drivers/platform/x86/intel_sgx_vma.c @@ -160,7 +160,6 @@ static struct sgx_encl_page *sgx_vma_do_fault(struct vm_area_struct *vma, struct sgx_epc_page *epc_page = NULL; struct sgx_epc_page *secs_epc_page = NULL; struct page *backing; - unsigned int free_flags = SGX_FREE_SKIP_EREMOVE; int rc; /* If process was forked, VMA is still there but vm_private_data is set @@ -253,8 +252,11 @@ static struct sgx_encl_page *sgx_vma_do_fault(struct vm_area_struct *vma, rc = vm_insert_pfn(vma, entry->addr, PFN_DOWN(epc_page->pa)); sgx_put_backing(backing, 0); + /* failure to insert a pfn after ELDU is fatal to the enclave */ if (rc) { - free_flags = 0; + sgx_warn(encl, "vm_insert_pfn in fault returned %d\n", rc); + zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start); + encl->flags |= SGX_ENCL_DEAD; entry = ERR_PTR(rc); goto out; } @@ -274,7 +276,7 @@ static struct sgx_encl_page *sgx_vma_do_fault(struct vm_area_struct *vma, out: mutex_unlock(&encl->lock); if (epc_page) - sgx_free_page(epc_page, encl, free_flags); + sgx_free_page(epc_page, encl, SGX_FREE_SKIP_EREMOVE); if (secs_epc_page) sgx_free_page(secs_epc_page, encl, SGX_FREE_SKIP_EREMOVE); return entry;