projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 51ae4a2d PA |
1 | /* |
| 2 | * Supervisor Mode Access Prevention support | |
| 3 | * | |
| 4 | * Copyright (C) 2012 Intel Corporation | |
| 5 | * Author: H. Peter Anvin <hpa@linux.intel.com> | |
| 6 | * | |
| 7 | * This program is free software; you can redistribute it and/or | |
| 8 | * modify it under the terms of the GNU General Public License | |
| 9 | * as published by the Free Software Foundation; version 2 | |
| 10 | * of the License. | |
| 11 | */ | |
| 12 | ||
| 13 | #ifndef _ASM_X86_SMAP_H | |
| 14 | #define _ASM_X86_SMAP_H | |
| 15 | ||
| 16 | #include <linux/stringify.h> | |
| 17 | #include <asm/nops.h> | |
| 18 | #include <asm/cpufeature.h> | |
| 19 | ||
| 20 | /* "Raw" instruction opcodes */ | |
| 21 | #define __ASM_CLAC .byte 0x0f,0x01,0xca | |
| 22 | #define __ASM_STAC .byte 0x0f,0x01,0xcb | |
| 23 | ||
| 24 | #ifdef __ASSEMBLY__ | |
| 25 | ||
| 26 | #include <asm/alternative-asm.h> | |
| 27 | ||
| 28 | #ifdef CONFIG_X86_SMAP | |
| 29 | ||
| 30 | #define ASM_CLAC \ | |
| 31 | 661: ASM_NOP3 ; \ | |
| 32 | .pushsection .altinstr_replacement, "ax" ; \ | |
| 33 | 662: __ASM_CLAC ; \ | |
| 34 | .popsection ; \ | |
| 35 | .pushsection .altinstructions, "a" ; \ | |
| 36 | altinstruction_entry 661b, 662b, X86_FEATURE_SMAP, 3, 3 ; \ | |
| 37 | .popsection | |
| 38 | ||
| 39 | #define ASM_STAC \ | |
| 40 | 661: ASM_NOP3 ; \ | |
| 41 | .pushsection .altinstr_replacement, "ax" ; \ | |
| 42 | 662: __ASM_STAC ; \ | |
| 43 | .popsection ; \ | |
| 44 | .pushsection .altinstructions, "a" ; \ | |
| 45 | altinstruction_entry 661b, 662b, X86_FEATURE_SMAP, 3, 3 ; \ | |
| 46 | .popsection | |
| 47 | ||
| 48 | #else /* CONFIG_X86_SMAP */ | |
| 49 | ||
| 50 | #define ASM_CLAC | |
| 51 | #define ASM_STAC | |
| 52 | ||
| 53 | #endif /* CONFIG_X86_SMAP */ | |
| 54 | ||
| 55 | #else /* __ASSEMBLY__ */ | |
| 56 | ||
| 57 | #include <asm/alternative.h> | |
| 58 | ||
| 59 | #ifdef CONFIG_X86_SMAP | |
| 60 | ||
| 63bcff2a | 61 | static __always_inline void clac(void) |
| 51ae4a2d PA |
62 | { |
| 63 | /* Note: a barrier is implicit in alternative() */ | |
| 64 | alternative(ASM_NOP3, __stringify(__ASM_CLAC), X86_FEATURE_SMAP); | |
| 65 | } | |
| 66 | ||
| 63bcff2a | 67 | static __always_inline void stac(void) |
| 51ae4a2d PA |
68 | { |
| 69 | /* Note: a barrier is implicit in alternative() */ | |
| 70 | alternative(ASM_NOP3, __stringify(__ASM_STAC), X86_FEATURE_SMAP); | |
| 71 | } | |
| 72 | ||
| 73 | /* These macros can be used in asm() statements */ | |
| 74 | #define ASM_CLAC \ | |
| 75 | ALTERNATIVE(ASM_NOP3, __stringify(__ASM_CLAC), X86_FEATURE_SMAP) | |
| 76 | #define ASM_STAC \ | |
| 77 | ALTERNATIVE(ASM_NOP3, __stringify(__ASM_STAC), X86_FEATURE_SMAP) | |
| 78 | ||
| 79 | #else /* CONFIG_X86_SMAP */ | |
| 80 | ||
| 81 | static inline void clac(void) { } | |
| 82 | static inline void stac(void) { } | |
| 83 | ||
| 84 | #define ASM_CLAC | |
| 85 | #define ASM_STAC | |
| 86 | ||
| 87 | #endif /* CONFIG_X86_SMAP */ | |
| 88 | ||
| 89 | #endif /* __ASSEMBLY__ */ | |
| 90 | ||
| 91 | #endif /* _ASM_X86_SMAP_H */ |