segment.h (84f53788458c95309b88948b69ff95921e9c74a8) segment.h (72d64cc76941cde45e65e2a5b9fb81d527963645)
1#ifndef _ASM_X86_SEGMENT_H
2#define _ASM_X86_SEGMENT_H
3
4#include <linux/const.h>
5
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 */
6/*
7 * Constructor for a conventional segment GDT (or LDT) entry.
8 * This is a macro so it can be used in initializers.
9 */
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
10#define GDT_ENTRY(flags, base, limit) \
11 ((((base) & _AC(0xff000000,ULL)) << (56-24)) | \
12 (((flags) & _AC(0x0000f0ff,ULL)) << 40) | \
13 (((limit) & _AC(0x000f0000,ULL)) << (48-16)) | \
14 (((base) & _AC(0x00ffffff,ULL)) << 16) | \
15 (((limit) & _AC(0x0000ffff,ULL))))
16
15/* Simple and small GDT entries for booting only */
17/* Simple and small GDT entries for booting only: */
16
17#define GDT_ENTRY_BOOT_CS 2
18#define GDT_ENTRY_BOOT_DS 3
19#define GDT_ENTRY_BOOT_TSS 4
18
19#define GDT_ENTRY_BOOT_CS 2
20#define GDT_ENTRY_BOOT_DS 3
21#define GDT_ENTRY_BOOT_TSS 4
20#define __BOOT_CS (GDT_ENTRY_BOOT_CS * 8)
21#define __BOOT_DS (GDT_ENTRY_BOOT_DS * 8)
22#define __BOOT_TSS (GDT_ENTRY_BOOT_TSS * 8)
22#define __BOOT_CS (GDT_ENTRY_BOOT_CS*8)
23#define __BOOT_DS (GDT_ENTRY_BOOT_DS*8)
24#define __BOOT_TSS (GDT_ENTRY_BOOT_TSS*8)
23
25
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 */
26/*
27 * Bottom two bits of selector give the ring
28 * privilege level
29 */
30#define SEGMENT_RPL_MASK 0x3
32
31
32/* User mode is privilege level 3: */
33#define USER_RPL 0x3
34
35/* Bit 2 is Table Indicator (TI): selects between LDT or GDT */
36#define SEGMENT_TI_MASK 0x4
37/* LDT segment has TI set ... */
38#define SEGMENT_LDT 0x4
39/* ... GDT has it cleared */
40#define SEGMENT_GDT 0x0
41
33#ifdef CONFIG_X86_32
34/*
35 * The layout of the per-CPU GDT under Linux:
36 *
42#ifdef CONFIG_X86_32
43/*
44 * The layout of the per-CPU GDT under Linux:
45 *
37 * 0 - null
46 * 0 - null <=== cacheline #1
38 * 1 - reserved
39 * 2 - reserved
40 * 3 - reserved
41 *
47 * 1 - reserved
48 * 2 - reserved
49 * 3 - reserved
50 *
42 * 4 - unused <==== new cacheline
51 * 4 - unused <=== cacheline #2
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 ]
52 * 5 - unused
53 *
54 * ------- start of TLS (Thread-Local Storage) segments:
55 *
56 * 6 - TLS segment #1 [ glibc's TLS segment ]
57 * 7 - TLS segment #2 [ Wine's %fs Win32 segment ]
49 * 8 - TLS segment #3
58 * 8 - TLS segment #3 <=== cacheline #3
50 * 9 - reserved
51 * 10 - reserved
52 * 11 - reserved
53 *
54 * ------- start of kernel segments:
55 *
59 * 9 - reserved
60 * 10 - reserved
61 * 11 - reserved
62 *
63 * ------- start of kernel segments:
64 *
56 * 12 - kernel code segment <==== new cacheline
65 * 12 - kernel code segment <=== cacheline #4
57 * 13 - kernel data segment
58 * 14 - default user CS
59 * 15 - default user DS
66 * 13 - kernel data segment
67 * 14 - default user CS
68 * 15 - default user DS
60 * 16 - TSS
69 * 16 - TSS <=== cacheline #5
61 * 17 - LDT
62 * 18 - PNPBIOS support (16->32 gate)
63 * 19 - PNPBIOS support
70 * 17 - LDT
71 * 18 - PNPBIOS support (16->32 gate)
72 * 19 - PNPBIOS support
64 * 20 - PNPBIOS support
73 * 20 - PNPBIOS support <=== cacheline #6
65 * 21 - PNPBIOS support
66 * 22 - PNPBIOS support
67 * 23 - APM BIOS support
74 * 21 - PNPBIOS support
75 * 22 - PNPBIOS support
76 * 23 - APM BIOS support
68 * 24 - APM BIOS support
77 * 24 - APM BIOS support <=== cacheline #7
69 * 25 - APM BIOS support
70 *
71 * 26 - ESPFIX small SS
72 * 27 - per-cpu [ offset to per-cpu data area ]
78 * 25 - APM BIOS support
79 *
80 * 26 - ESPFIX small SS
81 * 27 - per-cpu [ offset to per-cpu data area ]
73 * 28 - stack_canary-20 [ for stack protector ]
82 * 28 - stack_canary-20 [ for stack protector ] <=== cacheline #8
74 * 29 - unused
75 * 30 - unused
76 * 31 - TSS for double fault handler
77 */
83 * 29 - unused
84 * 30 - unused
85 * 31 - TSS for double fault handler
86 */
78#define GDT_ENTRY_TLS_MIN 6
79#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
87#define GDT_ENTRY_TLS_MIN 6
88#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
80
81#define GDT_ENTRY_KERNEL_CS 12
82#define GDT_ENTRY_KERNEL_DS 13
83#define GDT_ENTRY_DEFAULT_USER_CS 14
84#define GDT_ENTRY_DEFAULT_USER_DS 15
85#define GDT_ENTRY_TSS 16
86#define GDT_ENTRY_LDT 17
87#define GDT_ENTRY_PNPBIOS_CS32 18

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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
97
98#define GDT_ENTRY_DOUBLEFAULT_TSS 31
99
89
90#define GDT_ENTRY_KERNEL_CS 12
91#define GDT_ENTRY_KERNEL_DS 13
92#define GDT_ENTRY_DEFAULT_USER_CS 14
93#define GDT_ENTRY_DEFAULT_USER_DS 15
94#define GDT_ENTRY_TSS 16
95#define GDT_ENTRY_LDT 17
96#define GDT_ENTRY_PNPBIOS_CS32 18

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101#define GDT_ENTRY_APMBIOS_BASE 23
102
103#define GDT_ENTRY_ESPFIX_SS 26
104#define GDT_ENTRY_PERCPU 27
105#define GDT_ENTRY_STACK_CANARY 28
106
107#define GDT_ENTRY_DOUBLEFAULT_TSS 31
108
109/*
110 * Number of entries in the GDT table:
111 */
112#define GDT_ENTRIES 32
113
114/*
115 * Segment selector values corresponding to the above entries:
116 */
117
100#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8)
101#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
118#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8)
119#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)
120#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
121#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
104#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS*8)
122#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS*8)
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 */
123
124/* segment for calling fn: */
125#define PNP_CS32 (GDT_ENTRY_PNPBIOS_CS32*8)
126/* code segment for BIOS: */
127#define PNP_CS16 (GDT_ENTRY_PNPBIOS_CS16*8)
128
107/* "Is this PNP code selector (PNP_CS32 or PNP_CS16)?" */
129/* "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 */
130#define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == PNP_CS32)
131
132/* data segment for BIOS: */
133#define PNP_DS (GDT_ENTRY_PNPBIOS_DS*8)
134/* transfer data segment: */
135#define PNP_TS1 (GDT_ENTRY_PNPBIOS_TS1*8)
136/* another data segment: */
137#define PNP_TS2 (GDT_ENTRY_PNPBIOS_TS2*8)
138
112#ifdef CONFIG_SMP
139#ifdef CONFIG_SMP
113#define __KERNEL_PERCPU (GDT_ENTRY_PERCPU*8)
140# define __KERNEL_PERCPU (GDT_ENTRY_PERCPU*8)
114#else
141#else
115#define __KERNEL_PERCPU 0
142# define __KERNEL_PERCPU 0
116#endif
143#endif
144
117#ifdef CONFIG_CC_STACKPROTECTOR
145#ifdef CONFIG_CC_STACKPROTECTOR
118#define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY*8)
146# define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY*8)
119#else
147#else
120#define __KERNEL_STACK_CANARY 0
148# define __KERNEL_STACK_CANARY 0
121#endif
122
149#endif
150
123#define GDT_ENTRIES 32
124
125#else /* 64-bit: */
126
127#include <asm/cache.h>
128
151#else /* 64-bit: */
152
153#include <asm/cache.h>
154
129#define GDT_ENTRY_KERNEL32_CS 1
130#define GDT_ENTRY_KERNEL_CS 2
131#define GDT_ENTRY_KERNEL_DS 3
155#define GDT_ENTRY_KERNEL32_CS 1
156#define GDT_ENTRY_KERNEL_CS 2
157#define GDT_ENTRY_KERNEL_DS 3
158
132/*
159/*
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
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,
160 * We cannot use the same code segment descriptor for user and kernel mode,
161 * not even in long flat mode, because of different DPL.
162 *
163 * GDT layout to get 64-bit SYSCALL/SYSRET support right. SYSRET hardcodes
164 * selectors:
165 *
166 * if returning to 32-bit userspace: cs = STAR.SYSRET_CS,
167 * if returning to 64-bit userspace: cs = STAR.SYSRET_CS+16,
168 *
138 * ss = STAR.SYSRET_CS+8 (in either case)
169 * ss = STAR.SYSRET_CS+8 (in either case)
170 *
139 * thus USER_DS should be between 32-bit and 64-bit code selectors:
140 */
171 * thus USER_DS should be between 32-bit and 64-bit code selectors:
172 */
141#define GDT_ENTRY_DEFAULT_USER32_CS 4
142#define GDT_ENTRY_DEFAULT_USER_DS 5
143#define GDT_ENTRY_DEFAULT_USER_CS 6
173#define GDT_ENTRY_DEFAULT_USER32_CS 4
174#define GDT_ENTRY_DEFAULT_USER_DS 5
175#define GDT_ENTRY_DEFAULT_USER_CS 6
144
176
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
177/* Needs two entries */
178#define GDT_ENTRY_TSS 8
179/* Needs two entries */
180#define GDT_ENTRY_LDT 10
149
181
150#define GDT_ENTRY_PER_CPU 15 /* abused to load per CPU data from limit */
182#define GDT_ENTRY_TLS_MIN 12
183#define GDT_ENTRY_TLS_MAX 14
151
184
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)
185/* Abused to load per CPU data from limit */
186#define GDT_ENTRY_PER_CPU 15
161
187
162/* TLS indexes for 64bit - hardcoded in arch_prctl */
163#define FS_TLS 0
164#define GS_TLS 1
188/*
189 * Number of entries in the GDT table:
190 */
191#define GDT_ENTRIES 16
165
192
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)
193/*
194 * Segment selector values corresponding to the above entries:
195 *
196 * Note, selectors also need to have a correct RPL,
197 * expressed with the +3 value for user-space selectors:
198 */
199#define __KERNEL32_CS (GDT_ENTRY_KERNEL32_CS*8)
200#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8)
201#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
202#define __USER32_CS (GDT_ENTRY_DEFAULT_USER32_CS*8 + 3)
203#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
204#define __USER32_DS __USER_DS
205#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
206#define __PER_CPU_SEG (GDT_ENTRY_PER_CPU*8 + 3)
168
207
169#define GDT_ENTRIES 16
208/* TLS indexes for 64-bit - hardcoded in arch_prctl(): */
209#define FS_TLS 0
210#define GS_TLS 1
170
211
212#define GS_TLS_SEL ((GDT_ENTRY_TLS_MIN+GS_TLS)*8 + 3)
213#define FS_TLS_SEL ((GDT_ENTRY_TLS_MIN+FS_TLS)*8 + 3)
214
171#endif
172
173#ifndef CONFIG_PARAVIRT
215#endif
216
217#ifndef CONFIG_PARAVIRT
174#define get_kernel_rpl() 0
218# define get_kernel_rpl() 0
175#endif
176
219#endif
220
177#define IDT_ENTRIES 256
178#define NUM_EXCEPTION_VECTORS 32
179/* Bitmask of exception vectors which push an error code on the stack */
180#define EXCEPTION_ERRCODE_MASK 0x00027d00
181#define GDT_SIZE (GDT_ENTRIES * 8)
182#define GDT_ENTRY_TLS_ENTRIES 3
183#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)
221#define IDT_ENTRIES 256
222#define NUM_EXCEPTION_VECTORS 32
184
223
224/* Bitmask of exception vectors which push an error code on the stack: */
225#define EXCEPTION_ERRCODE_MASK 0x00027d00
226
227#define GDT_SIZE (GDT_ENTRIES*8)
228#define GDT_ENTRY_TLS_ENTRIES 3
229#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES* 8)
230
185#ifdef __KERNEL__
186#ifndef __ASSEMBLY__
231#ifdef __KERNEL__
232#ifndef __ASSEMBLY__
233
187extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][2+2+5];
188#ifdef CONFIG_TRACING
234extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][2+2+5];
235#ifdef CONFIG_TRACING
189#define trace_early_idt_handlers early_idt_handlers
236# define trace_early_idt_handlers early_idt_handlers
190#endif
191
192/*
193 * Load a segment. Fall back on loading the zero
194 * segment if something goes wrong..
195 */
196#define loadsegment(seg, value) \
197do { \

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206 ".previous \n" \
207 \
208 _ASM_EXTABLE(1b, 2b) \
209 \
210 : "+r" (__val) : : "memory"); \
211} while (0)
212
213/*
237#endif
238
239/*
240 * Load a segment. Fall back on loading the zero
241 * segment if something goes wrong..
242 */
243#define loadsegment(seg, value) \
244do { \

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253 ".previous \n" \
254 \
255 _ASM_EXTABLE(1b, 2b) \
256 \
257 : "+r" (__val) : : "memory"); \
258} while (0)
259
260/*
214 * Save a segment register away
261 * Save a segment register away:
215 */
216#define savesegment(seg, value) \
217 asm("mov %%" #seg ",%0":"=r" (value) : : "memory")
218
219/*
262 */
263#define savesegment(seg, value) \
264 asm("mov %%" #seg ",%0":"=r" (value) : : "memory")
265
266/*
220 * x86_32 user gs accessors.
267 * x86-32 user GS accessors:
221 */
222#ifdef CONFIG_X86_32
268 */
269#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 */
270# ifdef CONFIG_X86_32_LAZY_GS
271# define get_user_gs(regs) (u16)({ unsigned long v; savesegment(gs, v); v; })
272# define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v))
273# define task_user_gs(tsk) ((tsk)->thread.gs)
274# define lazy_save_gs(v) savesegment(gs, (v))
275# define lazy_load_gs(v) loadsegment(gs, (v))
276# else /* X86_32_LAZY_GS */
277# define get_user_gs(regs) (u16)((regs)->gs)
278# define set_user_gs(regs, v) do { (regs)->gs = (v); } while (0)
279# define task_user_gs(tsk) (task_pt_regs(tsk)->gs)
280# define lazy_save_gs(v) do { } while (0)
281# define lazy_load_gs(v) do { } while (0)
282# endif /* X86_32_LAZY_GS */
236#endif /* X86_32 */
237
283#endif /* X86_32 */
284
238static 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__ */
247
248#endif /* _ASM_X86_SEGMENT_H */
285#endif /* !__ASSEMBLY__ */
286#endif /* __KERNEL__ */
287
288#endif /* _ASM_X86_SEGMENT_H */