1#ifndef _ASM_X86_SEGMENT_H 2#define _ASM_X86_SEGMENT_H 3 4#include <linux/const.h> 5 6/* Constructor for a conventional segment GDT (or LDT) entry */ 7/* This is a macro so it can be used in initializers */ 8#define GDT_ENTRY(flags, base, limit) \ 9 ((((base) & _AC(0xff000000,ULL)) << (56-24)) | \ 10 (((flags) & _AC(0x0000f0ff,ULL)) << 40) | \ 11 (((limit) & _AC(0x000f0000,ULL)) << (48-16)) | \ 12 (((base) & _AC(0x00ffffff,ULL)) << 16) | \ 13 (((limit) & _AC(0x0000ffff,ULL)))) 14 15/* Simple and small GDT entries for booting only */ 16 17#define GDT_ENTRY_BOOT_CS 2 18#define __BOOT_CS (GDT_ENTRY_BOOT_CS * 8) 19 20#define GDT_ENTRY_BOOT_DS (GDT_ENTRY_BOOT_CS + 1) 21#define __BOOT_DS (GDT_ENTRY_BOOT_DS * 8) 22 23#define GDT_ENTRY_BOOT_TSS (GDT_ENTRY_BOOT_CS + 2) 24#define __BOOT_TSS (GDT_ENTRY_BOOT_TSS * 8) 25 26#ifdef CONFIG_X86_32 27/* 28 * The layout of the per-CPU GDT under Linux: 29 * 30 * 0 - null 31 * 1 - reserved 32 * 2 - reserved 33 * 3 - reserved 34 * 35 * 4 - unused <==== new cacheline 36 * 5 - unused 37 * 38 * ------- start of TLS (Thread-Local Storage) segments: 39 * 40 * 6 - TLS segment #1 [ glibc's TLS segment ] 41 * 7 - TLS segment #2 [ Wine's %fs Win32 segment ] 42 * 8 - TLS segment #3 43 * 9 - reserved 44 * 10 - reserved 45 * 11 - reserved 46 * 47 * ------- start of kernel segments: 48 * 49 * 12 - kernel code segment <==== new cacheline 50 * 13 - kernel data segment 51 * 14 - default user CS 52 * 15 - default user DS 53 * 16 - TSS 54 * 17 - LDT 55 * 18 - PNPBIOS support (16->32 gate) 56 * 19 - PNPBIOS support 57 * 20 - PNPBIOS support 58 * 21 - PNPBIOS support 59 * 22 - PNPBIOS support 60 * 23 - APM BIOS support 61 * 24 - APM BIOS support 62 * 25 - APM BIOS support 63 * 64 * 26 - ESPFIX small SS 65 * 27 - per-cpu [ offset to per-cpu data area ] 66 * 28 - stack_canary-20 [ for stack protector ] 67 * 29 - unused 68 * 30 - unused 69 * 31 - TSS for double fault handler 70 */ 71#define GDT_ENTRY_TLS_MIN 6 72#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1) 73 74#define GDT_ENTRY_DEFAULT_USER_CS 14 75 76#define GDT_ENTRY_DEFAULT_USER_DS 15 77 78#define GDT_ENTRY_KERNEL_BASE (12) 79 80#define GDT_ENTRY_KERNEL_CS (GDT_ENTRY_KERNEL_BASE+0) 81 82#define GDT_ENTRY_KERNEL_DS (GDT_ENTRY_KERNEL_BASE+1) 83 84#define GDT_ENTRY_TSS (GDT_ENTRY_KERNEL_BASE+4) 85#define GDT_ENTRY_LDT (GDT_ENTRY_KERNEL_BASE+5) 86 87#define GDT_ENTRY_PNPBIOS_BASE (GDT_ENTRY_KERNEL_BASE+6) 88#define GDT_ENTRY_APMBIOS_BASE (GDT_ENTRY_KERNEL_BASE+11) 89 90#define GDT_ENTRY_ESPFIX_SS (GDT_ENTRY_KERNEL_BASE+14) 91#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS*8) 92 93#define GDT_ENTRY_PERCPU (GDT_ENTRY_KERNEL_BASE+15) 94#ifdef CONFIG_SMP 95#define __KERNEL_PERCPU (GDT_ENTRY_PERCPU * 8) 96#else 97#define __KERNEL_PERCPU 0 98#endif 99 100#define GDT_ENTRY_STACK_CANARY (GDT_ENTRY_KERNEL_BASE+16) 101#ifdef CONFIG_CC_STACKPROTECTOR 102#define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY*8) 103#else 104#define __KERNEL_STACK_CANARY 0 105#endif 106 107#define GDT_ENTRY_DOUBLEFAULT_TSS 31 108 109/* 110 * The GDT has 32 entries 111 */ 112#define GDT_ENTRIES 32 113 114/* The PnP BIOS entries in the GDT */ 115#define GDT_ENTRY_PNPBIOS_CS32 (GDT_ENTRY_PNPBIOS_BASE + 0) 116#define GDT_ENTRY_PNPBIOS_CS16 (GDT_ENTRY_PNPBIOS_BASE + 1) 117#define GDT_ENTRY_PNPBIOS_DS (GDT_ENTRY_PNPBIOS_BASE + 2) 118#define GDT_ENTRY_PNPBIOS_TS1 (GDT_ENTRY_PNPBIOS_BASE + 3) 119#define GDT_ENTRY_PNPBIOS_TS2 (GDT_ENTRY_PNPBIOS_BASE + 4) 120 121/* The PnP BIOS selectors */ 122#define PNP_CS32 (GDT_ENTRY_PNPBIOS_CS32 * 8) /* segment for calling fn */ 123#define PNP_CS16 (GDT_ENTRY_PNPBIOS_CS16 * 8) /* code segment for BIOS */ 124#define PNP_DS (GDT_ENTRY_PNPBIOS_DS * 8) /* data segment for BIOS */ 125#define PNP_TS1 (GDT_ENTRY_PNPBIOS_TS1 * 8) /* transfer data segment */ 126#define PNP_TS2 (GDT_ENTRY_PNPBIOS_TS2 * 8) /* another data segment */ 127 128/* Bottom two bits of selector give the ring privilege level */ 129#define SEGMENT_RPL_MASK 0x3 130/* Bit 2 is table indicator (LDT/GDT) */ 131#define SEGMENT_TI_MASK 0x4 132 133/* User mode is privilege level 3 */ 134#define USER_RPL 0x3 135/* LDT segment has TI set, GDT has it cleared */ 136#define SEGMENT_LDT 0x4 137#define SEGMENT_GDT 0x0 138 139/* 140 * Matching rules for certain types of segments. 141 */ 142 143/* Matches PNP_CS32 and PNP_CS16 (they must be consecutive) */ 144#define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == GDT_ENTRY_PNPBIOS_BASE * 8) 145 146 147#else 148#include <asm/cache.h> 149 150#define GDT_ENTRY_KERNEL32_CS 1 151#define GDT_ENTRY_KERNEL_CS 2 152#define GDT_ENTRY_KERNEL_DS 3 153 154#define __KERNEL32_CS (GDT_ENTRY_KERNEL32_CS * 8) 155 156/* 157 * we cannot use the same code segment descriptor for user and kernel 158 * -- not even in the long flat mode, because of different DPL /kkeil 159 * The segment offset needs to contain a RPL. Grr. -AK 160 * GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets) 161 */ 162#define GDT_ENTRY_DEFAULT_USER32_CS 4 163#define GDT_ENTRY_DEFAULT_USER_DS 5 164#define GDT_ENTRY_DEFAULT_USER_CS 6 165#define __USER32_CS (GDT_ENTRY_DEFAULT_USER32_CS*8+3) 166#define __USER32_DS __USER_DS 167 168#define GDT_ENTRY_TSS 8 /* needs two entries */ 169#define GDT_ENTRY_LDT 10 /* needs two entries */ 170#define GDT_ENTRY_TLS_MIN 12 171#define GDT_ENTRY_TLS_MAX 14 172 173#define GDT_ENTRY_PER_CPU 15 /* Abused to load per CPU data from limit */ 174#define __PER_CPU_SEG (GDT_ENTRY_PER_CPU * 8 + 3) 175 176/* TLS indexes for 64bit - hardcoded in arch_prctl */ 177#define FS_TLS 0 178#define GS_TLS 1 179 180#define GS_TLS_SEL ((GDT_ENTRY_TLS_MIN+GS_TLS)*8 + 3) 181#define FS_TLS_SEL ((GDT_ENTRY_TLS_MIN+FS_TLS)*8 + 3) 182 183#define GDT_ENTRIES 16 184 185#endif 186 187#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8) 188#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8) 189#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8+3) 190#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8+3) 191#ifndef CONFIG_PARAVIRT 192#define get_kernel_rpl() 0 193#endif 194 195/* User mode is privilege level 3 */ 196#define USER_RPL 0x3 197/* LDT segment has TI set, GDT has it cleared */ 198#define SEGMENT_LDT 0x4 199#define SEGMENT_GDT 0x0 200 201/* Bottom two bits of selector give the ring privilege level */ 202#define SEGMENT_RPL_MASK 0x3 203/* Bit 2 is table indicator (LDT/GDT) */ 204#define SEGMENT_TI_MASK 0x4 205 206#define IDT_ENTRIES 256 207#define NUM_EXCEPTION_VECTORS 32 208#define GDT_SIZE (GDT_ENTRIES * 8) 209#define GDT_ENTRY_TLS_ENTRIES 3 210#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8) 211 212#ifdef __KERNEL__ 213#ifndef __ASSEMBLY__ 214extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][10]; 215#endif 216#endif 217 218#endif /* _ASM_X86_SEGMENT_H */ 219