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1965aae3 PA |
1 | #ifndef _ASM_X86_SEGMENT_H |
2 | #define _ASM_X86_SEGMENT_H | |
cef18950 | 3 | |
014eea51 PA |
4 | #include <linux/const.h> |
5 | ||
4fdf08b5 PA |
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) \ | |
014eea51 PA |
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)))) | |
4fdf08b5 | 14 | |
2a6648e6 PA |
15 | /* Simple and small GDT entries for booting only */ |
16 | ||
17 | #define GDT_ENTRY_BOOT_CS 2 | |
84f53788 DV |
18 | #define GDT_ENTRY_BOOT_DS 3 |
19 | #define GDT_ENTRY_BOOT_TSS 4 | |
2a6648e6 | 20 | #define __BOOT_CS (GDT_ENTRY_BOOT_CS * 8) |
2a6648e6 | 21 | #define __BOOT_DS (GDT_ENTRY_BOOT_DS * 8) |
88089519 PA |
22 | #define __BOOT_TSS (GDT_ENTRY_BOOT_TSS * 8) |
23 | ||
be9d1738 BP |
24 | #define SEGMENT_RPL_MASK 0x3 /* |
25 | * Bottom two bits of selector give the ring | |
26 | * privilege level | |
27 | */ | |
28 | #define SEGMENT_TI_MASK 0x4 /* Bit 2 is table indicator (LDT/GDT) */ | |
29 | #define USER_RPL 0x3 /* User mode is privilege level 3 */ | |
30 | #define SEGMENT_LDT 0x4 /* LDT segment has TI set... */ | |
31 | #define SEGMENT_GDT 0x0 /* ... GDT has it cleared */ | |
32 | ||
96a388de | 33 | #ifdef CONFIG_X86_32 |
b23be399 GOC |
34 | /* |
35 | * The layout of the per-CPU GDT under Linux: | |
36 | * | |
37 | * 0 - null | |
38 | * 1 - reserved | |
39 | * 2 - reserved | |
40 | * 3 - reserved | |
41 | * | |
42 | * 4 - unused <==== new cacheline | |
43 | * 5 - unused | |
44 | * | |
45 | * ------- start of TLS (Thread-Local Storage) segments: | |
46 | * | |
47 | * 6 - TLS segment #1 [ glibc's TLS segment ] | |
48 | * 7 - TLS segment #2 [ Wine's %fs Win32 segment ] | |
49 | * 8 - TLS segment #3 | |
50 | * 9 - reserved | |
51 | * 10 - reserved | |
52 | * 11 - reserved | |
53 | * | |
54 | * ------- start of kernel segments: | |
55 | * | |
56 | * 12 - kernel code segment <==== new cacheline | |
57 | * 13 - kernel data segment | |
58 | * 14 - default user CS | |
59 | * 15 - default user DS | |
60 | * 16 - TSS | |
61 | * 17 - LDT | |
62 | * 18 - PNPBIOS support (16->32 gate) | |
63 | * 19 - PNPBIOS support | |
64 | * 20 - PNPBIOS support | |
65 | * 21 - PNPBIOS support | |
66 | * 22 - PNPBIOS support | |
67 | * 23 - APM BIOS support | |
68 | * 24 - APM BIOS support | |
69 | * 25 - APM BIOS support | |
70 | * | |
71 | * 26 - ESPFIX small SS | |
72 | * 27 - per-cpu [ offset to per-cpu data area ] | |
60a5317f | 73 | * 28 - stack_canary-20 [ for stack protector ] |
b23be399 GOC |
74 | * 29 - unused |
75 | * 30 - unused | |
76 | * 31 - TSS for double fault handler | |
77 | */ | |
78 | #define GDT_ENTRY_TLS_MIN 6 | |
79 | #define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1) | |
80 | ||
84f53788 DV |
81 | #define GDT_ENTRY_KERNEL_CS 12 |
82 | #define GDT_ENTRY_KERNEL_DS 13 | |
b23be399 | 83 | #define GDT_ENTRY_DEFAULT_USER_CS 14 |
b23be399 | 84 | #define GDT_ENTRY_DEFAULT_USER_DS 15 |
84f53788 DV |
85 | #define GDT_ENTRY_TSS 16 |
86 | #define GDT_ENTRY_LDT 17 | |
87 | #define GDT_ENTRY_PNPBIOS_CS32 18 | |
88 | #define GDT_ENTRY_PNPBIOS_CS16 19 | |
89 | #define GDT_ENTRY_PNPBIOS_DS 20 | |
90 | #define GDT_ENTRY_PNPBIOS_TS1 21 | |
91 | #define GDT_ENTRY_PNPBIOS_TS2 22 | |
92 | #define GDT_ENTRY_APMBIOS_BASE 23 | |
93 | ||
94 | #define GDT_ENTRY_ESPFIX_SS 26 | |
95 | #define GDT_ENTRY_PERCPU 27 | |
96 | #define GDT_ENTRY_STACK_CANARY 28 | |
b23be399 | 97 | |
84f53788 | 98 | #define GDT_ENTRY_DOUBLEFAULT_TSS 31 |
b23be399 | 99 | |
84f53788 DV |
100 | #define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8) |
101 | #define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8) | |
102 | #define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8+3) | |
103 | #define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8+3) | |
3234282f | 104 | #define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS*8) |
84f53788 DV |
105 | #define PNP_CS32 (GDT_ENTRY_PNPBIOS_CS32 * 8) /* segment for calling fn */ |
106 | #define PNP_CS16 (GDT_ENTRY_PNPBIOS_CS16 * 8) /* code segment for BIOS */ | |
107 | /* "Is this PNP code selector (PNP_CS32 or PNP_CS16)?" */ | |
108 | #define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == PNP_CS32) | |
109 | #define PNP_DS (GDT_ENTRY_PNPBIOS_DS * 8) /* data segment for BIOS */ | |
110 | #define PNP_TS1 (GDT_ENTRY_PNPBIOS_TS1 * 8) /* transfer data segment */ | |
111 | #define PNP_TS2 (GDT_ENTRY_PNPBIOS_TS2 * 8) /* another data segment */ | |
b23be399 | 112 | #ifdef CONFIG_SMP |
84f53788 | 113 | #define __KERNEL_PERCPU (GDT_ENTRY_PERCPU*8) |
b23be399 | 114 | #else |
84f53788 | 115 | #define __KERNEL_PERCPU 0 |
b23be399 | 116 | #endif |
60a5317f | 117 | #ifdef CONFIG_CC_STACKPROTECTOR |
3234282f | 118 | #define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY*8) |
60a5317f TH |
119 | #else |
120 | #define __KERNEL_STACK_CANARY 0 | |
121 | #endif | |
122 | ||
b23be399 GOC |
123 | #define GDT_ENTRIES 32 |
124 | ||
84f53788 | 125 | #else /* 64-bit: */ |
b23be399 | 126 | |
b23be399 GOC |
127 | #include <asm/cache.h> |
128 | ||
84f53788 DV |
129 | #define GDT_ENTRY_KERNEL32_CS 1 |
130 | #define GDT_ENTRY_KERNEL_CS 2 | |
131 | #define GDT_ENTRY_KERNEL_DS 3 | |
b23be399 GOC |
132 | /* |
133 | * we cannot use the same code segment descriptor for user and kernel | |
134 | * -- not even in the long flat mode, because of different DPL /kkeil | |
84f53788 DV |
135 | * GDT layout to get 64bit syscall/sysret right. sysret hardcodes selectors: |
136 | * if returning to 32-bit userspace: cs = STAR.SYSRET_CS, | |
137 | * if returning to 64-bit userspace: cs = STAR.SYSRET_CS+16, | |
138 | * ss = STAR.SYSRET_CS+8 (in either case) | |
139 | * thus USER_DS should be between 32-bit and 64-bit code selectors: | |
b23be399 | 140 | */ |
a939098a GC |
141 | #define GDT_ENTRY_DEFAULT_USER32_CS 4 |
142 | #define GDT_ENTRY_DEFAULT_USER_DS 5 | |
143 | #define GDT_ENTRY_DEFAULT_USER_CS 6 | |
b23be399 | 144 | |
84f53788 DV |
145 | #define GDT_ENTRY_TSS 8 /* needs two entries */ |
146 | #define GDT_ENTRY_LDT 10 /* needs two entries */ | |
147 | #define GDT_ENTRY_TLS_MIN 12 | |
148 | #define GDT_ENTRY_TLS_MAX 14 | |
b23be399 | 149 | |
84f53788 DV |
150 | #define GDT_ENTRY_PER_CPU 15 /* abused to load per CPU data from limit */ |
151 | ||
152 | /* Selectors need to also have a correct RPL (+3 thingy) */ | |
153 | #define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8) | |
154 | #define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8) | |
155 | #define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8+3) | |
156 | #define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8+3) | |
157 | #define __KERNEL32_CS (GDT_ENTRY_KERNEL32_CS*8) | |
158 | #define __USER32_CS (GDT_ENTRY_DEFAULT_USER32_CS*8+3) | |
159 | #define __USER32_DS __USER_DS | |
160 | #define __PER_CPU_SEG (GDT_ENTRY_PER_CPU*8+3) | |
b23be399 GOC |
161 | |
162 | /* TLS indexes for 64bit - hardcoded in arch_prctl */ | |
163 | #define FS_TLS 0 | |
164 | #define GS_TLS 1 | |
165 | ||
166 | #define GS_TLS_SEL ((GDT_ENTRY_TLS_MIN+GS_TLS)*8 + 3) | |
167 | #define FS_TLS_SEL ((GDT_ENTRY_TLS_MIN+FS_TLS)*8 + 3) | |
168 | ||
169 | #define GDT_ENTRIES 16 | |
170 | ||
96a388de | 171 | #endif |
cef18950 GOC |
172 | |
173 | #ifndef CONFIG_PARAVIRT | |
174 | #define get_kernel_rpl() 0 | |
175 | #endif | |
176 | ||
15ee09b4 | 177 | #define IDT_ENTRIES 256 |
5524ea32 | 178 | #define NUM_EXCEPTION_VECTORS 32 |
84f4fc52 PA |
179 | /* Bitmask of exception vectors which push an error code on the stack */ |
180 | #define EXCEPTION_ERRCODE_MASK 0x00027d00 | |
15ee09b4 GOC |
181 | #define GDT_SIZE (GDT_ENTRIES * 8) |
182 | #define GDT_ENTRY_TLS_ENTRIES 3 | |
183 | #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8) | |
184 | ||
8866cd9d RM |
185 | #ifdef __KERNEL__ |
186 | #ifndef __ASSEMBLY__ | |
9900aa2f | 187 | extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][2+2+5]; |
25c74b10 SA |
188 | #ifdef CONFIG_TRACING |
189 | #define trace_early_idt_handlers early_idt_handlers | |
190 | #endif | |
f05e798a DH |
191 | |
192 | /* | |
193 | * Load a segment. Fall back on loading the zero | |
194 | * segment if something goes wrong.. | |
195 | */ | |
196 | #define loadsegment(seg, value) \ | |
197 | do { \ | |
198 | unsigned short __val = (value); \ | |
199 | \ | |
200 | asm volatile(" \n" \ | |
201 | "1: movl %k0,%%" #seg " \n" \ | |
202 | \ | |
203 | ".section .fixup,\"ax\" \n" \ | |
204 | "2: xorl %k0,%k0 \n" \ | |
205 | " jmp 1b \n" \ | |
206 | ".previous \n" \ | |
207 | \ | |
208 | _ASM_EXTABLE(1b, 2b) \ | |
209 | \ | |
210 | : "+r" (__val) : : "memory"); \ | |
211 | } while (0) | |
212 | ||
213 | /* | |
214 | * Save a segment register away | |
215 | */ | |
216 | #define savesegment(seg, value) \ | |
217 | asm("mov %%" #seg ",%0":"=r" (value) : : "memory") | |
218 | ||
219 | /* | |
220 | * x86_32 user gs accessors. | |
221 | */ | |
222 | #ifdef CONFIG_X86_32 | |
223 | #ifdef CONFIG_X86_32_LAZY_GS | |
224 | #define get_user_gs(regs) (u16)({unsigned long v; savesegment(gs, v); v;}) | |
225 | #define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v)) | |
226 | #define task_user_gs(tsk) ((tsk)->thread.gs) | |
227 | #define lazy_save_gs(v) savesegment(gs, (v)) | |
228 | #define lazy_load_gs(v) loadsegment(gs, (v)) | |
229 | #else /* X86_32_LAZY_GS */ | |
230 | #define get_user_gs(regs) (u16)((regs)->gs) | |
231 | #define set_user_gs(regs, v) do { (regs)->gs = (v); } while (0) | |
232 | #define task_user_gs(tsk) (task_pt_regs(tsk)->gs) | |
233 | #define lazy_save_gs(v) do { } while (0) | |
234 | #define lazy_load_gs(v) do { } while (0) | |
235 | #endif /* X86_32_LAZY_GS */ | |
236 | #endif /* X86_32 */ | |
237 | ||
238 | static inline unsigned long get_limit(unsigned long segment) | |
239 | { | |
240 | unsigned long __limit; | |
241 | asm("lsll %1,%0" : "=r" (__limit) : "r" (segment)); | |
242 | return __limit + 1; | |
243 | } | |
244 | ||
245 | #endif /* !__ASSEMBLY__ */ | |
246 | #endif /* __KERNEL__ */ | |
8866cd9d | 247 | |
1965aae3 | 248 | #endif /* _ASM_X86_SEGMENT_H */ |