Re: [PATCH v36 12/24] x86/sgx: Add SGX_IOC_ENCLAVE_CREATE

From: Haitao Huang
Date: Tue Sep 01 2020 - 12:41:39 EST

On Thu, 16 Jul 2020 08:52:51 -0500, Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote:

Add an ioctl that performs ENCLS[ECREATE], which creates SGX Enclave
Control Structure for the enclave. SECS contains attributes about the
enclave that are used by the hardware and cannot be directly accessed by
software, as SECS resides in the EPC.

One essential field in SECS is a field that stores the SHA256 of the
measured enclave pages. This field, MRENCLAVE, is initialized by the
ECREATE instruction and updated by every EADD and EEXTEND operation.
Finally, EINIT locks down the value.

Acked-by: Jethro Beekman <jethro@xxxxxxxxxxxx>
Tested-by: Jethro Beekman <jethro@xxxxxxxxxxxx>
Tested-by: Haitao Huang <haitao.huang@xxxxxxxxxxxxxxx>
Tested-by: Chunyang Hui <sanqian.hcy@xxxxxxxxxx>
Tested-by: Jordan Hand <jorhand@xxxxxxxxxxxxxxxxxxx>
Tested-by: Nathaniel McCallum <npmccallum@xxxxxxxxxx>
Tested-by: Seth Moore <sethmo@xxxxxxxxxx>
Co-developed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Co-developed-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
.../userspace-api/ioctl/ioctl-number.rst | 1 +
arch/x86/include/uapi/asm/sgx.h | 25 ++
arch/x86/kernel/cpu/sgx/Makefile | 1 +
arch/x86/kernel/cpu/sgx/driver.c | 12 +
arch/x86/kernel/cpu/sgx/driver.h | 1 +
arch/x86/kernel/cpu/sgx/ioctl.c | 226 ++++++++++++++++++
6 files changed, 266 insertions(+)
create mode 100644 arch/x86/include/uapi/asm/sgx.h
create mode 100644 arch/x86/kernel/cpu/sgx/ioctl.c

diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index 59472cd6a11d..35f713e3a267 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -323,6 +323,7 @@ Code Seq# Include File Comments
<mailto:tlewis@xxxxxxxxxxxxxx>
0xA3 90-9F linux/dtlk.h
0xA4 00-1F uapi/linux/tee.h Generic TEE subsystem
+0xA4 00-1F uapi/asm/sgx.h Intel SGX subsystem (a legit conflict as TEE and SGX do not co-exist)
0xAA 00-3F linux/uapi/linux/userfaultfd.h
0xAB 00-1F linux/nbd.h
0xAC 00-1F linux/raw.h
diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h
new file mode 100644
index 000000000000..3787d278e84b
--- /dev/null
+++ b/arch/x86/include/uapi/asm/sgx.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) WITH Linux-syscall-note */
+/*
+ * Copyright(c) 2016-19 Intel Corporation.
+ */
+#ifndef _UAPI_ASM_X86_SGX_H
+#define _UAPI_ASM_X86_SGX_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+#define SGX_MAGIC 0xA4
+
+#define SGX_IOC_ENCLAVE_CREATE \
+ _IOW(SGX_MAGIC, 0x00, struct sgx_enclave_create)
+
+/**
+ * struct sgx_enclave_create - parameter structure for the
+ * %SGX_IOC_ENCLAVE_CREATE ioctl
+ * @src: address for the SECS page data
+ */
+struct sgx_enclave_create {
+ __u64 src;
+};
+
+#endif /* _UAPI_ASM_X86_SGX_H */
diff --git a/arch/x86/kernel/cpu/sgx/Makefile b/arch/x86/kernel/cpu/sgx/Makefile
index 3fc451120735..91d3dc784a29 100644
--- a/arch/x86/kernel/cpu/sgx/Makefile
+++ b/arch/x86/kernel/cpu/sgx/Makefile
@@ -1,4 +1,5 @@
obj-y += \
driver.o \
encl.o \
+ ioctl.o \
main.o
diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c
index b52520407f5b..5559bc18de41 100644
--- a/arch/x86/kernel/cpu/sgx/driver.c
+++ b/arch/x86/kernel/cpu/sgx/driver.c
@@ -118,10 +118,22 @@ static unsigned long sgx_get_unmapped_area(struct file *file,
return current->mm->get_unmapped_area(file, addr, len, pgoff, flags);
}
+#ifdef CONFIG_COMPAT
+static long sgx_compat_ioctl(struct file *filep, unsigned int cmd,
+ unsigned long arg)
+{
+ return sgx_ioctl(filep, cmd, arg);
+}
+#endif
+
static const struct file_operations sgx_encl_fops = {
.owner = THIS_MODULE,
.open = sgx_open,
.release = sgx_release,
+ .unlocked_ioctl = sgx_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = sgx_compat_ioctl,
+#endif
.mmap = sgx_mmap,
.get_unmapped_area = sgx_get_unmapped_area,
};
diff --git a/arch/x86/kernel/cpu/sgx/driver.h b/arch/x86/kernel/cpu/sgx/driver.h
index f7ce40dedc91..e4063923115b 100644
--- a/arch/x86/kernel/cpu/sgx/driver.h
+++ b/arch/x86/kernel/cpu/sgx/driver.h
@@ -9,6 +9,7 @@
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/workqueue.h>
+#include <uapi/asm/sgx.h>
#include "sgx.h"
#define SGX_EINIT_SPIN_COUNT 20
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
new file mode 100644
index 000000000000..7981c411b05a
--- /dev/null
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2016-19 Intel Corporation.
+
+#include <asm/mman.h>
+#include <linux/mman.h>
+#include <linux/delay.h>
+#include <linux/file.h>
+#include <linux/hashtable.h>
+#include <linux/highmem.h>
+#include <linux/ratelimit.h>
+#include <linux/sched/signal.h>
+#include <linux/shmem_fs.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+#include "driver.h"
+#include "encl.h"
+#include "encls.h"
+
+static u32 sgx_calc_ssa_frame_size(u32 miscselect, u64 xfrm)
+{
+ u32 size_max = PAGE_SIZE;
+ u32 size;
+ int i;
+
+ for (i = 2; i < 64; i++) {
+ if (!((1 << i) & xfrm))
+ continue;
+

Potential overflow for signed integer shift. Originally spotted and fixed in OOT from Colin I. K.: https://github.com/intel/linux-sgx-driver/pull/16

Thanks
Haitao