From patchwork Thu Aug 8 00:12:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 11083017 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3944213B1 for ; Thu, 8 Aug 2019 00:13:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 24E4B28AD2 for ; Thu, 8 Aug 2019 00:13:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 197C428AD4; Thu, 8 Aug 2019 00:13:02 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9CEEF28AD3 for ; Thu, 8 Aug 2019 00:13:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388917AbfHHANB (ORCPT ); Wed, 7 Aug 2019 20:13:01 -0400 Received: from mga09.intel.com ([134.134.136.24]:51237 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389045AbfHHANB (ORCPT ); Wed, 7 Aug 2019 20:13:01 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Aug 2019 17:12:58 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,358,1559545200"; d="scan'208";a="165519376" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.41]) by orsmga007.jf.intel.com with ESMTP; 07 Aug 2019 17:12:58 -0700 From: Sean Christopherson To: Jarkko Sakkinen Cc: linux-sgx@vger.kernel.org, Shay Katz-zamir , Serge Ayoun Subject: [PATCH for_v22 11/11] x86/sgx: Shrink the enclave if ECREATE/EADD fails Date: Wed, 7 Aug 2019 17:12:54 -0700 Message-Id: <20190808001254.11926-12-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190808001254.11926-1-sean.j.christopherson@intel.com> References: <20190808001254.11926-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add sgx_encl_shrink() to pair with sgx_encl_grow() and use it to adjust the VA page count when ECREATE or EADD fails. Return the allocated VA page from sgx_encl_grow() so that it can be freed during shrink. Signed-off-by: Sean Christopherson Acked-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/sgx/driver/ioctl.c | 55 +++++++++++++++++++------- 1 file changed, 40 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/driver/ioctl.c b/arch/x86/kernel/cpu/sgx/driver/ioctl.c index a531cf615f3c..173a405d59a5 100644 --- a/arch/x86/kernel/cpu/sgx/driver/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/driver/ioctl.c @@ -22,16 +22,17 @@ struct sgx_add_page_req { struct list_head list; }; -static int sgx_encl_grow(struct sgx_encl *encl, unsigned int disallowed_flags) +static struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl, + unsigned int disallowed_flags) { - struct sgx_va_page *va_page; - int ret; + struct sgx_va_page *va_page = NULL; + void *err; BUILD_BUG_ON(SGX_VA_SLOT_COUNT != (SGX_ENCL_PAGE_VA_OFFSET_MASK >> 3) + 1); if (encl->flags & disallowed_flags) - return -EFAULT; + return ERR_PTR(-EFAULT); if (!(encl->page_cnt % SGX_VA_SLOT_COUNT)) { mutex_unlock(&encl->lock); @@ -46,22 +47,34 @@ static int sgx_encl_grow(struct sgx_encl *encl, unsigned int disallowed_flags) mutex_lock(&encl->lock); if (IS_ERR(va_page->epc_page)) { - ret = PTR_ERR(va_page->epc_page); + err = ERR_CAST(va_page->epc_page); kfree(va_page); - return ret; + return err; } else if (encl->flags & disallowed_flags) { sgx_free_page(va_page->epc_page); kfree(va_page); - return -EFAULT; + return ERR_PTR(-EFAULT); } else if (encl->page_cnt % SGX_VA_SLOT_COUNT) { sgx_free_page(va_page->epc_page); kfree(va_page); + va_page = NULL; } else { list_add(&va_page->list, &encl->va_pages); } } encl->page_cnt++; - return 0; + return va_page; +} + +static void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page) +{ + encl->page_cnt--; + + if (va_page) { + sgx_free_page(va_page->epc_page); + list_del(&va_page->list); + kfree(va_page); + } } static bool sgx_process_add_page_req(struct sgx_add_page_req *req, @@ -260,6 +273,7 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) { unsigned long encl_size = secs->size + PAGE_SIZE; struct sgx_epc_page *secs_epc; + struct sgx_va_page *va_page; unsigned long ssaframesize; struct sgx_pageinfo pginfo; struct sgx_secinfo secinfo; @@ -268,21 +282,23 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) mutex_lock(&encl->lock); - ret = sgx_encl_grow(encl, SGX_ENCL_CREATED | SGX_ENCL_DEAD); - if (ret) + va_page = sgx_encl_grow(encl, SGX_ENCL_CREATED | SGX_ENCL_DEAD); + if (IS_ERR(va_page)) { + ret = PTR_ERR(va_page); goto err_out_unlock; + } ssaframesize = sgx_calc_ssaframesize(secs->miscselect, secs->xfrm); if (sgx_validate_secs(secs, ssaframesize)) { ret = -EINVAL; - goto err_out_unlock; + goto err_out_shrink; } backing = shmem_file_setup("SGX backing", encl_size + (encl_size >> 5), VM_NORESERVE); if (IS_ERR(backing)) { ret = PTR_ERR(backing); - goto err_out_unlock; + goto err_out_shrink; } encl->backing = backing; @@ -337,6 +353,9 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) fput(encl->backing); encl->backing = NULL; +err_out_shrink: + sgx_encl_shrink(encl, va_page); + err_out_unlock: mutex_unlock(&encl->lock); return ret; @@ -496,6 +515,7 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long addr, { u64 page_type = secinfo->flags & SGX_SECINFO_PAGE_TYPE_MASK; struct sgx_encl_page *encl_page; + struct sgx_va_page *va_page; int ret; if (sgx_validate_secinfo(secinfo)) @@ -508,14 +528,16 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long addr, mutex_lock(&encl->lock); - ret = sgx_encl_grow(encl, SGX_ENCL_INITIALIZED | SGX_ENCL_DEAD); - if (ret) + va_page = sgx_encl_grow(encl, SGX_ENCL_INITIALIZED | SGX_ENCL_DEAD); + if (IS_ERR(va_page)) { + ret = PTR_ERR(va_page); goto err_out_unlock; + } encl_page = sgx_encl_page_alloc(encl, addr, prot); if (IS_ERR(encl_page)) { ret = PTR_ERR(encl_page); - goto err_out_unlock; + goto err_out_shrink; } ret = __sgx_encl_add_page(encl, encl_page, data, secinfo, mrmask); @@ -530,6 +552,9 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long addr, PFN_DOWN(encl_page->desc)); kfree(encl_page); +err_out_shrink: + sgx_encl_shrink(encl, va_page); + err_out_unlock: mutex_unlock(&encl->lock); return ret;