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- /*
- * Copyright (C) 2011-2017 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 "xsave.h"
- #include "util.h"
- #include "se_detect.h"
- #include "sgx_attributes.h"
- #define XFRM_YMM_BITMASK 0x00000004
- // save_and_clean_xfeature_regs()
- // do fwait, fxsave, and then clear the upper bits of YMM regs before executing EENTER.
- // Parameters:
- // buffer - if the pointer is not NULL, save the CPU state to the buffer
- // Return Value:
- // none
- void save_and_clean_xfeature_regs(uint8_t *buffer)
- {
- // XCR0 is not supposed to be changed. So query it once.
- static uint64_t xcr0 = 0;
- if(xcr0 == 0)
- {
- if(false == try_read_xcr0(&xcr0))
- {
- xcr0 = SGX_XFRM_LEGACY;
- }
- }
- // do fwait to flush the float-point exceptions
- do_fwait();
- // do fxsave to save the CPU state before ecall
- // no need to save the CPU state before oret
- if(buffer != 0)
- {
- uint8_t *buf = (uint8_t*)ROUND_TO((size_t)buffer, FXSAVE_ALIGN_SIZE);
- do_fxsave(buf);
- }
- // clean the upper bits of the YMM regs
- if(xcr0 & XFRM_YMM_BITMASK)
- {
- do_vzeroupper();
- }
- }
- void restore_xfeature_regs(const uint8_t *buffer)
- {
- if (buffer)
- {
- uint8_t *buf = (uint8_t*)ROUND_TO((size_t)buffer, FXSAVE_ALIGN_SIZE);
- do_fxrstor(buf);
- }
- }
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