corda/sdk/trts/trts_xsave.cpp
Angie Chinchilla 9441de4c38 Initial release of Intel SGX for Linux.
This release is used in conjunction with the linux-sgx-driver Intial release:
https://github.com/01org/linux-sgx-driver
commit-id: 0e865ce5e6b297a787bcdc12d98bada8174be6d7

Intel-id: 33399

Signed-off-by: Angie Chinchilla <angie.v.chinchilla@intel.com>
2016-06-23 18:51:53 -04:00

113 lines
4.0 KiB
C++

/*
* Copyright (C) 2011-2016 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "arch.h"
#include "xsave.h"
#include "trts_inst.h"
#include "util.h"
// 'SYNTHETIC_STATE' buffer size is (512 + 64 + 256) bytes
// 512 for fxsave buffer,
// 64 for xsave header,
// 256 for YMM State (16 * 16 bytes of each YMMH-register)
// and the buffer should be 64 byte aligned.
#define SYNTHETIC_STATE_SIZE (512 + 64 + 256)
se_static_assert(SYNTHETIC_STATE_SIZE <= SE_PAGE_SIZE);
static SE_DECLSPEC_ALIGN(4096) const uint16_t
SYNTHETIC_STATE[SYNTHETIC_STATE_SIZE/sizeof(uint16_t)] = {
0x037F, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x1F80, 0, 0xFFFF, 0
};
static int g_xsave_enabled; // flag to indicate whether xsave is enabled or not
// EENTER will set xcr0 with secs.attr.xfrm,
// So use the xfeature mask from report instead of calling xgetbv
uint64_t get_xfeature_state()
{
// target_info and report_data are useless
// we only need to make sure their alignment and within enclave
// so set the pointers to SYNTHETIC_STATE
sgx_target_info_t *target_info = (sgx_target_info_t *)SYNTHETIC_STATE;
sgx_report_data_t *report_data = (sgx_report_data_t *)SYNTHETIC_STATE;
uint8_t buffer[sizeof(sgx_report_t) + REPORT_ALIGN_SIZE -1] = {0};
sgx_report_t *report = (sgx_report_t *)ROUND_TO((size_t)buffer, REPORT_ALIGN_SIZE);
do_ereport(target_info, report_data, report);
g_xsave_enabled = (report->body.attributes.xfrm == SGX_XFRM_LEGACY) ? 0 : 1;
uint64_t xfrm = report->body.attributes.xfrm;
// no secrets in target_info, report_data, and report. no need to clear them before return
// tlibc functions cannot be used before calling init_optimized_libs().
return xfrm;
}
// save_and_clean_xfeature_regs()
// do fwait, fxsave, and then clean the extended feature registers
// Parameters:
// buffer - If the pointer is not NULL, save the CPU state to the memory
// Return Value:
// none
void save_and_clean_xfeature_regs(uint8_t *buffer)
{
do_fwait();
if(buffer != 0)
{
uint8_t *buf = (uint8_t*)ROUND_TO((size_t)buffer, FXSAVE_ALIGN_SIZE);
do_fxsave(buf);
}
if(g_xsave_enabled)
{
do_xrstor(SYNTHETIC_STATE);
}
else
{
do_fxrstor(SYNTHETIC_STATE);
}
}
// restore_xfeature_regs()
// restore the extended feature registers
//
void restore_xfeature_regs(const uint8_t *buffer)
{
if(buffer != 0)
{
uint8_t *buf = (uint8_t*)ROUND_TO((size_t)buffer, FXSAVE_ALIGN_SIZE);
do_fxrstor(buf);
}
}