1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_NOPS_H 3 #define _ASM_X86_NOPS_H 4 5 #include <asm/asm.h> 6 7 /* 8 * Define nops for use with alternative() and for tracing. 9 */ 10 11 #ifndef CONFIG_64BIT 12 13 /* 14 * Generic 32bit nops from GAS: 15 * 16 * 1: nop 17 * 2: movl %esi,%esi 18 * 3: leal 0x0(%esi),%esi 19 * 4: leal 0x0(%esi,%eiz,1),%esi 20 * 5: leal %ds:0x0(%esi,%eiz,1),%esi 21 * 6: leal 0x0(%esi),%esi 22 * 7: leal 0x0(%esi,%eiz,1),%esi 23 * 8: leal %ds:0x0(%esi,%eiz,1),%esi 24 * 25 * Except 5 and 8, which are DS prefixed 4 and 7 resp, where GAS would emit 2 26 * nop instructions. 27 */ 28 #define BYTES_NOP1 0x90 29 #define BYTES_NOP2 0x89,0xf6 30 #define BYTES_NOP3 0x8d,0x76,0x00 31 #define BYTES_NOP4 0x8d,0x74,0x26,0x00 32 #define BYTES_NOP5 0x3e,BYTES_NOP4 33 #define BYTES_NOP6 0x8d,0xb6,0x00,0x00,0x00,0x00 34 #define BYTES_NOP7 0x8d,0xb4,0x26,0x00,0x00,0x00,0x00 35 #define BYTES_NOP8 0x3e,BYTES_NOP7 36 37 #define ASM_NOP_MAX 8 38 39 #else 40 41 /* 42 * Generic 64bit nops from GAS: 43 * 44 * 1: nop 45 * 2: osp nop 46 * 3: nopl (%eax) 47 * 4: nopl 0x00(%eax) 48 * 5: nopl 0x00(%eax,%eax,1) 49 * 6: osp nopl 0x00(%eax,%eax,1) 50 * 7: nopl 0x00000000(%eax) 51 * 8: nopl 0x00000000(%eax,%eax,1) 52 * 9: cs nopl 0x00000000(%eax,%eax,1) 53 * 10: osp cs nopl 0x00000000(%eax,%eax,1) 54 * 11: osp osp cs nopl 0x00000000(%eax,%eax,1) 55 */ 56 #define BYTES_NOP1 0x90 57 #define BYTES_NOP2 0x66,BYTES_NOP1 58 #define BYTES_NOP3 0x0f,0x1f,0x00 59 #define BYTES_NOP4 0x0f,0x1f,0x40,0x00 60 #define BYTES_NOP5 0x0f,0x1f,0x44,0x00,0x00 61 #define BYTES_NOP6 0x66,BYTES_NOP5 62 #define BYTES_NOP7 0x0f,0x1f,0x80,0x00,0x00,0x00,0x00 63 #define BYTES_NOP8 0x0f,0x1f,0x84,0x00,0x00,0x00,0x00,0x00 64 #define BYTES_NOP9 0x2e,BYTES_NOP8 65 #define BYTES_NOP10 0x66,BYTES_NOP9 66 #define BYTES_NOP11 0x66,BYTES_NOP10 67 68 #define ASM_NOP9 _ASM_BYTES(BYTES_NOP9) 69 #define ASM_NOP10 _ASM_BYTES(BYTES_NOP10) 70 #define ASM_NOP11 _ASM_BYTES(BYTES_NOP11) 71 72 #define ASM_NOP_MAX 11 73 74 #endif /* CONFIG_64BIT */ 75 76 #define ASM_NOP1 _ASM_BYTES(BYTES_NOP1) 77 #define ASM_NOP2 _ASM_BYTES(BYTES_NOP2) 78 #define ASM_NOP3 _ASM_BYTES(BYTES_NOP3) 79 #define ASM_NOP4 _ASM_BYTES(BYTES_NOP4) 80 #define ASM_NOP5 _ASM_BYTES(BYTES_NOP5) 81 #define ASM_NOP6 _ASM_BYTES(BYTES_NOP6) 82 #define ASM_NOP7 _ASM_BYTES(BYTES_NOP7) 83 #define ASM_NOP8 _ASM_BYTES(BYTES_NOP8) 84 85 #ifndef __ASSEMBLY__ 86 extern const unsigned char * const x86_nops[]; 87 #endif 88 89 #endif /* _ASM_X86_NOPS_H */ 90