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669f8a9001
... and drop unfolded version. No need for ASM_NOP3 anymore either as the alternatives do the proper padding at build time and insert proper NOPs at boot time. There should be no apparent operational change from this patch. Signed-off-by: Borislav Petkov <bp@suse.de>
79 lines
1.7 KiB
C
79 lines
1.7 KiB
C
/*
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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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