From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
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 <jarkko.sakkinen@linux.intel.com>,
Darren Hart <dvhart@infradead.org>,
Andy Shevchenko <andy@infradead.org>
Subject: [PATCH v9 5/7] intel_sgx: ptrace() support
Date: Sat, 16 Dec 2017 18:19:52 +0200 [thread overview]
Message-ID: <20171216162200.20243-6-jarkko.sakkinen@linux.intel.com> (raw)
In-Reply-To: <20171216162200.20243-1-jarkko.sakkinen@linux.intel.com>
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 <jarkko.sakkinen@linux.intel.com>
Tested-by: Serge Ayoun <serge.ayoun@intel.com>
---
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
next prev parent reply other threads:[~2017-12-16 16:28 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-16 16:19 [PATCH v9 0/7] Intel SGX Driver Jarkko Sakkinen
2017-12-16 16:19 ` [PATCH v9 1/7] intel_sgx: updated MAINTAINERS Jarkko Sakkinen
2017-12-16 16:19 ` [PATCH v9 2/7] x86: add SGX definitions to cpufeature Jarkko Sakkinen
2017-12-16 16:19 ` [PATCH v9 3/7] x86: add SGX definitions to msr-index.h Jarkko Sakkinen
2017-12-16 16:19 ` [PATCH v9 4/7] intel_sgx: driver for Intel Software Guard Extensions Jarkko Sakkinen
2017-12-16 18:31 ` Philippe Ombredanne
2017-12-17 16:01 ` Jarkko Sakkinen
2017-12-16 16:19 ` Jarkko Sakkinen [this message]
2017-12-16 16:19 ` [PATCH v9 6/7] intel_sgx: driver documentation Jarkko Sakkinen
2017-12-16 16:19 ` [PATCH v9 7/7] intel_sgx: in-kernel launch enclave Jarkko Sakkinen
2017-12-19 13:59 ` Jarkko Sakkinen
2017-12-19 15:36 ` Andy Shevchenko
2017-12-19 23:57 ` Jarkko Sakkinen
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