Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752615AbdLGB6d (ORCPT ); Wed, 6 Dec 2017 20:58:33 -0500 Received: from mga07.intel.com ([134.134.136.100]:56362 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752248AbdLGB6Z (ORCPT ); Wed, 6 Dec 2017 20:58:25 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.45,370,1508828400"; d="scan'208";a="156691483" From: Jarkko Sakkinen To: intel-sgx-kernel-dev@lists.01.org, platform-driver-x86@vger.kernel.org, x86@kernel.org Cc: linux-kernel@vger.kernel.org, Jarkko Sakkinen , Darren Hart , Andy Shevchenko Subject: [PATCH v7 5/8] intel_sgx: ptrace() support Date: Thu, 7 Dec 2017 03:54:05 +0200 Message-Id: <20171207015614.7914-6-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20171207015614.7914-1-jarkko.sakkinen@linux.intel.com> References: <20171207015614.7914-1-jarkko.sakkinen@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3730 Lines: 143 Implemented VMA callbacks in order to ptrace() 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 | 119 +++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) diff --git a/drivers/platform/x86/intel_sgx/sgx_vma.c b/drivers/platform/x86/intel_sgx/sgx_vma.c index 481f671f10ca..2bce40ef6823 100644 --- a/drivers/platform/x86/intel_sgx/sgx_vma.c +++ b/drivers/platform/x86/intel_sgx/sgx_vma.c @@ -110,8 +110,127 @@ 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; + void *ptr; + int ret; + + offset = addr & ~PAGE_MASK; + + if ((page->desc & SGX_ENCL_PAGE_TCS) && + (offset + sizeof(unsigned long)) > + offsetof(struct sgx_tcs, reserved)) + return -ECANCELED; + + ptr = sgx_get_page(page->epc_page); + ret = __edbgrd((unsigned long)ptr + offset, data); + sgx_put_page(ptr); + if (ret) { + sgx_dbg(encl, "EDBGRD returned %d\n", ret); + return -EFAULT; + } + + return 0; +} + +static int sgx_edbgwr(struct sgx_encl *encl, struct sgx_encl_page *page, + unsigned long addr, void *data) +{ + unsigned long offset; + void *ptr; + 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) && + (offset + sizeof(unsigned long)) > + offsetof(struct sgx_tcs, flags)) + return -ECANCELED; + + ptr = sgx_get_page(page->epc_page); + ret = __edbgwr((unsigned long)ptr + offset, data); + sgx_put_page(ptr); + if (ret) { + sgx_dbg(encl, "EDBGWR returned %d\n", ret); + return -EFAULT; + } + + 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, + SGX_FAULT_RESERVE); + 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) + return ret; + + memcpy(data + offset, buf + i, cnt); + + if (write) { + ret = sgx_edbgwr(encl, entry, align, data); + if (ret) + return ret; + } + } + + if (entry) + entry->desc &= ~SGX_ENCL_PAGE_RESERVED; + + return (ret < 0 && ret != -ECANCELED) ? 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, }; -- 2.14.1