507e413a2d
libunwind currently supports shadow stack based on the Intel CET and AArch64 GCS technology, but throughout related codes, the Intel-specific keyword, "CET", is used to refer to the generic concept of control-flow integrity/shadow stack. This patch replaces such wordings with architecture-neutral term "shadow stack" (abbr. "shstk") to allow future implementation to avoid using the Intel-specific "CET" term.
64 lines
2.7 KiB
C
64 lines
2.7 KiB
C
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//
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//===----------------------------------------------------------------------===//
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#ifndef LIBUNWIND_SHADOW_STACK_UNWIND_H
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#define LIBUNWIND_SHADOW_STACK_UNWIND_H
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#include "libunwind.h"
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// Currently, CET is implemented on Linux x86 platforms.
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#if defined(_LIBUNWIND_TARGET_LINUX) && defined(__CET__) && defined(__SHSTK__)
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#define _LIBUNWIND_USE_CET 1
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#endif
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#if defined(_LIBUNWIND_USE_CET)
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#include <cet.h>
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#include <immintrin.h>
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#define _LIBUNWIND_POP_SHSTK_SSP(x) \
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do { \
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unsigned long ssp = _get_ssp(); \
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if (ssp != 0) { \
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unsigned int tmp = (x); \
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while (tmp > 255) { \
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_inc_ssp(255); \
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tmp -= 255; \
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} \
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_inc_ssp(tmp); \
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} \
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} while (0)
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#endif
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// On AArch64 we use _LIBUNWIND_USE_GCS to indicate that GCS is supported. We
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// need to guard any use of GCS instructions with __chkfeat though, as GCS may
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// not be enabled.
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#if defined(_LIBUNWIND_TARGET_AARCH64) && defined(__ARM_FEATURE_GCS_DEFAULT)
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#include <arm_acle.h>
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// We can only use GCS if arm_acle.h defines the GCS intrinsics.
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#ifdef _CHKFEAT_GCS
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#define _LIBUNWIND_USE_GCS 1
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#endif
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#define _LIBUNWIND_POP_SHSTK_SSP(x) \
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do { \
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if (__chkfeat(_CHKFEAT_GCS)) { \
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unsigned tmp = (x); \
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while (tmp--) \
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__gcspopm(); \
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} \
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} while (0)
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#endif
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extern void *__libunwind_shstk_get_registers(unw_cursor_t *);
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extern void *__libunwind_shstk_get_jump_target(void);
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#endif
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