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1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef LIBUNWIND_SHADOW_STACK_UNWIND_H
11#define LIBUNWIND_SHADOW_STACK_UNWIND_H
12
13#include "libunwind.h"
14
15// Currently, CET is implemented on Linux x86 platforms.
16#if defined(_LIBUNWIND_TARGET_LINUX) && defined(__CET__) && defined(__SHSTK__)
17#define _LIBUNWIND_USE_CET 1
18#endif
19
20#if defined(_LIBUNWIND_USE_CET)
21#include <cet.h>
22#include <immintrin.h>
23
24#define _LIBUNWIND_POP_SHSTK_SSP(x) \
25 do { \
26 unsigned long ssp = _get_ssp(); \
27 if (ssp != 0) { \
28 unsigned int tmp = (x); \
29 while (tmp > 255) { \
30 _inc_ssp(255); \
31 tmp -= 255; \
32 } \
33 _inc_ssp(tmp); \
34 } \
35 } while (0)
36#endif
37
38// On AArch64 we use _LIBUNWIND_USE_GCS to indicate that GCS is supported. We
39// need to guard any use of GCS instructions with __chkfeat though, as GCS may
40// not be enabled.
41#if defined(_LIBUNWIND_TARGET_AARCH64) && defined(__ARM_FEATURE_GCS_DEFAULT)
42#include <arm_acle.h>
43
44// We can only use GCS if arm_acle.h defines the GCS intrinsics.
45#ifdef _CHKFEAT_GCS
46#define _LIBUNWIND_USE_GCS 1
47#endif
48
49#define _LIBUNWIND_POP_SHSTK_SSP(x) \
50 do { \
51 if (__chkfeat(_CHKFEAT_GCS)) { \
52 unsigned tmp = (x); \
53 while (tmp--) \
54 __gcspopm(); \
55 } \
56 } while (0)
57
58#endif
59
60extern void *__libunwind_shstk_get_registers(unw_cursor_t *);
61extern void *__libunwind_shstk_get_jump_target(void);
62
63#endif