From patchwork Tue Nov 6 13:46:00 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 10670527 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 3058E13AD for ; Tue, 6 Nov 2018 13:55:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1F53B29D7D for ; Tue, 6 Nov 2018 13:55:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 12F2029E96; Tue, 6 Nov 2018 13:55:39 +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 95D4329D7D for ; Tue, 6 Nov 2018 13:55:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388496AbeKFXU7 (ORCPT ); Tue, 6 Nov 2018 18:20:59 -0500 Received: from mga14.intel.com ([192.55.52.115]:2849 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388358AbeKFXU6 (ORCPT ); Tue, 6 Nov 2018 18:20:58 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Nov 2018 05:55:37 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,472,1534834800"; d="scan'208";a="84373727" Received: from fhoeg-mobl.ger.corp.intel.com (HELO localhost) ([10.249.254.66]) by fmsmga008.fm.intel.com with ESMTP; 06 Nov 2018 05:55:32 -0800 From: Jarkko Sakkinen To: x86@kernel.org, platform-driver-x86@vger.kernel.org, linux-sgx@vger.kernel.org Cc: dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, serge.ayoun@intel.com, shay.katz-zamir@intel.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, Jarkko Sakkinen , Darren Hart , Andy Shevchenko , Suresh Siddha , linux-kernel@vger.kernel.org (open list) Subject: [PATCH v16 21/22] platform/x86: ptrace() support for the SGX driver Date: Tue, 6 Nov 2018 15:46:00 +0200 Message-Id: <20181106134758.10572-22-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181106134758.10572-1-jarkko.sakkinen@linux.intel.com> References: <20181106134758.10572-1-jarkko.sakkinen@linux.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 VMA callbacks for ptrace() that can be used with debug enclaves. With debug enclaves data can be read and write the memory word at a time by using ENCLS(EDBGRD) and ENCLS(EDBGWR) leaf instructions. Signed-off-by: Jarkko Sakkinen --- drivers/platform/x86/intel_sgx/sgx_vma.c | 109 +++++++++++++++++++++++ 1 file changed, 109 insertions(+) diff --git a/drivers/platform/x86/intel_sgx/sgx_vma.c b/drivers/platform/x86/intel_sgx/sgx_vma.c index cc0993b4fd40..df604e4d0d0a 100644 --- a/drivers/platform/x86/intel_sgx/sgx_vma.c +++ b/drivers/platform/x86/intel_sgx/sgx_vma.c @@ -51,8 +51,117 @@ static int sgx_vma_fault(struct vm_fault *vmf) return VM_FAULT_SIGBUS; } +static int sgx_edbgrd(struct sgx_encl *encl, struct sgx_encl_page *page, + unsigned long addr, void *data) +{ + unsigned long offset; + int ret; + + offset = addr & ~PAGE_MASK; + + if ((page->desc & SGX_ENCL_PAGE_TCS) && + offset > offsetof(struct sgx_tcs, gs_limit)) + return -ECANCELED; + + ret = __edbgrd(sgx_epc_addr(page->epc_page) + offset, data); + if (ret) { + sgx_dbg(encl, "EDBGRD returned %d\n", ret); + return encls_to_err(ret); + } + + return 0; +} + +static int sgx_edbgwr(struct sgx_encl *encl, struct sgx_encl_page *page, + unsigned long addr, void *data) +{ + unsigned long offset; + int ret; + + offset = addr & ~PAGE_MASK; + + /* Writing anything else than flags will cause #GP */ + if ((page->desc & SGX_ENCL_PAGE_TCS) && + offset != offsetof(struct sgx_tcs, flags)) + return -ECANCELED; + + ret = __edbgwr(sgx_epc_addr(page->epc_page) + offset, data); + if (ret) { + sgx_dbg(encl, "EDBGWR returned %d\n", ret); + return encls_to_err(ret); + } + + return 0; +} + +static int sgx_vma_access(struct vm_area_struct *vma, unsigned long addr, + void *buf, int len, int write) +{ + struct sgx_encl *encl = vma->vm_private_data; + struct sgx_encl_page *entry = NULL; + unsigned long align; + char data[sizeof(unsigned long)]; + int offset; + int cnt; + int ret = 0; + int i; + + /* If process was forked, VMA is still there but vm_private_data is set + * to NULL. + */ + if (!encl) + return -EFAULT; + + if (!(encl->flags & SGX_ENCL_DEBUG) || + !(encl->flags & SGX_ENCL_INITIALIZED) || + (encl->flags & SGX_ENCL_DEAD)) + return -EFAULT; + + for (i = 0; i < len; i += cnt) { + if (!entry || !((addr + i) & (PAGE_SIZE - 1))) { + if (entry) + entry->desc &= ~SGX_ENCL_PAGE_RESERVED; + + entry = sgx_fault_page(vma, (addr + i) & PAGE_MASK, + true); + if (IS_ERR(entry)) { + ret = PTR_ERR(entry); + entry = NULL; + break; + } + } + + /* Locking is not needed because only immutable fields of the + * page are accessed and page itself is reserved so that it + * cannot be swapped out in the middle. + */ + + align = ALIGN_DOWN(addr + i, sizeof(unsigned long)); + offset = (addr + i) & (sizeof(unsigned long) - 1); + cnt = sizeof(unsigned long) - offset; + cnt = min(cnt, len - i); + + ret = sgx_edbgrd(encl, entry, align, data); + if (ret) + break; + if (write) { + memcpy(data + offset, buf + i, cnt); + ret = sgx_edbgwr(encl, entry, align, data); + if (ret) + break; + } else + memcpy(buf + i, data + offset, cnt); + } + + if (entry) + entry->desc &= ~SGX_ENCL_PAGE_RESERVED; + + return ret < 0 ? ret : i; +} + const struct vm_operations_struct sgx_vm_ops = { .close = sgx_vma_close, .open = sgx_vma_open, .fault = sgx_vma_fault, + .access = sgx_vma_access, };