kolibrios/drivers/include/asm/smap.h
Sergey Semyonov (Serge) 66fbaa74b0 ddk: v4.6.7
git-svn-id: svn://kolibrios.org@7143 a494cfbc-eb01-0410-851d-a64ba20cac60
2018-02-02 14:53:42 +00:00

80 lines
1.7 KiB
C

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