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79 lines
1.7 KiB
79 lines
1.7 KiB
/* |
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* Supervisor Mode Access Prevention support |
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* |
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* Copyright (C) 2012 Intel Corporation |
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* Author: H. Peter Anvin <hpa@linux.intel.com> |
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* |
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* This program is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU General Public License |
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* as published by the Free Software Foundation; version 2 |
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* of the License. |
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*/ |
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#ifndef _ASM_X86_SMAP_H |
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#define _ASM_X86_SMAP_H |
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#include <linux/stringify.h> |
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#include <asm/nops.h> |
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#include <asm/cpufeature.h> |
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/* "Raw" instruction opcodes */ |
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#define __ASM_CLAC .byte 0x0f,0x01,0xca |
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#define __ASM_STAC .byte 0x0f,0x01,0xcb |
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#ifdef __ASSEMBLY__ |
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#include <asm/alternative-asm.h> |
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#ifdef CONFIG_X86_SMAP |
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#define ASM_CLAC \ |
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ALTERNATIVE "", __stringify(__ASM_CLAC), X86_FEATURE_SMAP |
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#define ASM_STAC \ |
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ALTERNATIVE "", __stringify(__ASM_STAC), X86_FEATURE_SMAP |
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#else /* CONFIG_X86_SMAP */ |
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#define ASM_CLAC |
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#define ASM_STAC |
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#endif /* CONFIG_X86_SMAP */ |
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#else /* __ASSEMBLY__ */ |
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#include <asm/alternative.h> |
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#ifdef CONFIG_X86_SMAP |
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static __always_inline void clac(void) |
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{ |
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/* Note: a barrier is implicit in alternative() */ |
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alternative("", __stringify(__ASM_CLAC), X86_FEATURE_SMAP); |
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} |
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static __always_inline void stac(void) |
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{ |
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/* Note: a barrier is implicit in alternative() */ |
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alternative("", __stringify(__ASM_STAC), X86_FEATURE_SMAP); |
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} |
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/* These macros can be used in asm() statements */ |
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#define ASM_CLAC \ |
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ALTERNATIVE("", __stringify(__ASM_CLAC), X86_FEATURE_SMAP) |
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#define ASM_STAC \ |
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ALTERNATIVE("", __stringify(__ASM_STAC), X86_FEATURE_SMAP) |
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#else /* CONFIG_X86_SMAP */ |
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static inline void clac(void) { } |
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static inline void stac(void) { } |
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#define ASM_CLAC |
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#define ASM_STAC |
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#endif /* CONFIG_X86_SMAP */ |
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#endif /* __ASSEMBLY__ */ |
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#endif /* _ASM_X86_SMAP_H */
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