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-rw-r--r--arch/x86/include/asm/segment.h289
1 files changed, 157 insertions, 132 deletions
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index db257a58571f..5a9856eb12ba 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -3,8 +3,10 @@
3 3
4#include <linux/const.h> 4#include <linux/const.h>
5 5
6/* Constructor for a conventional segment GDT (or LDT) entry */ 6/*
7/* This is a macro so it can be used in initializers */ 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) \ 10#define GDT_ENTRY(flags, base, limit) \
9 ((((base) & _AC(0xff000000,ULL)) << (56-24)) | \ 11 ((((base) & _AC(0xff000000,ULL)) << (56-24)) | \
10 (((flags) & _AC(0x0000f0ff,ULL)) << 40) | \ 12 (((flags) & _AC(0x0000f0ff,ULL)) << 40) | \
@@ -12,198 +14,228 @@
12 (((base) & _AC(0x00ffffff,ULL)) << 16) | \ 14 (((base) & _AC(0x00ffffff,ULL)) << 16) | \
13 (((limit) & _AC(0x0000ffff,ULL)))) 15 (((limit) & _AC(0x0000ffff,ULL))))
14 16
15/* Simple and small GDT entries for booting only */ 17/* Simple and small GDT entries for booting only: */
16 18
17#define GDT_ENTRY_BOOT_CS 2 19#define GDT_ENTRY_BOOT_CS 2
18#define __BOOT_CS (GDT_ENTRY_BOOT_CS * 8) 20#define GDT_ENTRY_BOOT_DS 3
21#define GDT_ENTRY_BOOT_TSS 4
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)
25
26/*
27 * Bottom two bits of selector give the ring
28 * privilege level
29 */
30#define SEGMENT_RPL_MASK 0x3
19 31
20#define GDT_ENTRY_BOOT_DS (GDT_ENTRY_BOOT_CS + 1) 32/* User mode is privilege level 3: */
21#define __BOOT_DS (GDT_ENTRY_BOOT_DS * 8) 33#define USER_RPL 0x3
22 34
23#define GDT_ENTRY_BOOT_TSS (GDT_ENTRY_BOOT_CS + 2) 35/* Bit 2 is Table Indicator (TI): selects between LDT or GDT */
24#define __BOOT_TSS (GDT_ENTRY_BOOT_TSS * 8) 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
25 41
26#define SEGMENT_RPL_MASK 0x3 /* 42#define GDT_ENTRY_INVALID_SEG 0
27 * Bottom two bits of selector give the ring
28 * privilege level
29 */
30#define SEGMENT_TI_MASK 0x4 /* Bit 2 is table indicator (LDT/GDT) */
31#define USER_RPL 0x3 /* User mode is privilege level 3 */
32#define SEGMENT_LDT 0x4 /* LDT segment has TI set... */
33#define SEGMENT_GDT 0x0 /* ... GDT has it cleared */
34 43
35#ifdef CONFIG_X86_32 44#ifdef CONFIG_X86_32
36/* 45/*
37 * The layout of the per-CPU GDT under Linux: 46 * The layout of the per-CPU GDT under Linux:
38 * 47 *
39 * 0 - null 48 * 0 - null <=== cacheline #1
40 * 1 - reserved 49 * 1 - reserved
41 * 2 - reserved 50 * 2 - reserved
42 * 3 - reserved 51 * 3 - reserved
43 * 52 *
44 * 4 - unused <==== new cacheline 53 * 4 - unused <=== cacheline #2
45 * 5 - unused 54 * 5 - unused
46 * 55 *
47 * ------- start of TLS (Thread-Local Storage) segments: 56 * ------- start of TLS (Thread-Local Storage) segments:
48 * 57 *
49 * 6 - TLS segment #1 [ glibc's TLS segment ] 58 * 6 - TLS segment #1 [ glibc's TLS segment ]
50 * 7 - TLS segment #2 [ Wine's %fs Win32 segment ] 59 * 7 - TLS segment #2 [ Wine's %fs Win32 segment ]
51 * 8 - TLS segment #3 60 * 8 - TLS segment #3 <=== cacheline #3
52 * 9 - reserved 61 * 9 - reserved
53 * 10 - reserved 62 * 10 - reserved
54 * 11 - reserved 63 * 11 - reserved
55 * 64 *
56 * ------- start of kernel segments: 65 * ------- start of kernel segments:
57 * 66 *
58 * 12 - kernel code segment <==== new cacheline 67 * 12 - kernel code segment <=== cacheline #4
59 * 13 - kernel data segment 68 * 13 - kernel data segment
60 * 14 - default user CS 69 * 14 - default user CS
61 * 15 - default user DS 70 * 15 - default user DS
62 * 16 - TSS 71 * 16 - TSS <=== cacheline #5
63 * 17 - LDT 72 * 17 - LDT
64 * 18 - PNPBIOS support (16->32 gate) 73 * 18 - PNPBIOS support (16->32 gate)
65 * 19 - PNPBIOS support 74 * 19 - PNPBIOS support
66 * 20 - PNPBIOS support 75 * 20 - PNPBIOS support <=== cacheline #6
67 * 21 - PNPBIOS support 76 * 21 - PNPBIOS support
68 * 22 - PNPBIOS support 77 * 22 - PNPBIOS support
69 * 23 - APM BIOS support 78 * 23 - APM BIOS support
70 * 24 - APM BIOS support 79 * 24 - APM BIOS support <=== cacheline #7
71 * 25 - APM BIOS support 80 * 25 - APM BIOS support
72 * 81 *
73 * 26 - ESPFIX small SS 82 * 26 - ESPFIX small SS
74 * 27 - per-cpu [ offset to per-cpu data area ] 83 * 27 - per-cpu [ offset to per-cpu data area ]
75 * 28 - stack_canary-20 [ for stack protector ] 84 * 28 - stack_canary-20 [ for stack protector ] <=== cacheline #8
76 * 29 - unused 85 * 29 - unused
77 * 30 - unused 86 * 30 - unused
78 * 31 - TSS for double fault handler 87 * 31 - TSS for double fault handler
79 */ 88 */
80#define GDT_ENTRY_TLS_MIN 6 89#define GDT_ENTRY_TLS_MIN 6
81#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1) 90#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
82 91
92#define GDT_ENTRY_KERNEL_CS 12
93#define GDT_ENTRY_KERNEL_DS 13
83#define GDT_ENTRY_DEFAULT_USER_CS 14 94#define GDT_ENTRY_DEFAULT_USER_CS 14
84
85#define GDT_ENTRY_DEFAULT_USER_DS 15 95#define GDT_ENTRY_DEFAULT_USER_DS 15
96#define GDT_ENTRY_TSS 16
97#define GDT_ENTRY_LDT 17
98#define GDT_ENTRY_PNPBIOS_CS32 18
99#define GDT_ENTRY_PNPBIOS_CS16 19
100#define GDT_ENTRY_PNPBIOS_DS 20
101#define GDT_ENTRY_PNPBIOS_TS1 21
102#define GDT_ENTRY_PNPBIOS_TS2 22
103#define GDT_ENTRY_APMBIOS_BASE 23
104
105#define GDT_ENTRY_ESPFIX_SS 26
106#define GDT_ENTRY_PERCPU 27
107#define GDT_ENTRY_STACK_CANARY 28
108
109#define GDT_ENTRY_DOUBLEFAULT_TSS 31
86 110
87#define GDT_ENTRY_KERNEL_BASE (12) 111/*
112 * Number of entries in the GDT table:
113 */
114#define GDT_ENTRIES 32
88 115
89#define GDT_ENTRY_KERNEL_CS (GDT_ENTRY_KERNEL_BASE+0) 116/*
117 * Segment selector values corresponding to the above entries:
118 */
90 119
91#define GDT_ENTRY_KERNEL_DS (GDT_ENTRY_KERNEL_BASE+1) 120#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8)
121#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
122#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
123#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
124#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS*8)
92 125
93#define GDT_ENTRY_TSS (GDT_ENTRY_KERNEL_BASE+4) 126/* segment for calling fn: */
94#define GDT_ENTRY_LDT (GDT_ENTRY_KERNEL_BASE+5) 127#define PNP_CS32 (GDT_ENTRY_PNPBIOS_CS32*8)
128/* code segment for BIOS: */
129#define PNP_CS16 (GDT_ENTRY_PNPBIOS_CS16*8)
95 130
96#define GDT_ENTRY_PNPBIOS_BASE (GDT_ENTRY_KERNEL_BASE+6) 131/* "Is this PNP code selector (PNP_CS32 or PNP_CS16)?" */
97#define GDT_ENTRY_APMBIOS_BASE (GDT_ENTRY_KERNEL_BASE+11) 132#define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == PNP_CS32)
98 133
99#define GDT_ENTRY_ESPFIX_SS (GDT_ENTRY_KERNEL_BASE+14) 134/* data segment for BIOS: */
100#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS*8) 135#define PNP_DS (GDT_ENTRY_PNPBIOS_DS*8)
136/* transfer data segment: */
137#define PNP_TS1 (GDT_ENTRY_PNPBIOS_TS1*8)
138/* another data segment: */
139#define PNP_TS2 (GDT_ENTRY_PNPBIOS_TS2*8)
101 140
102#define GDT_ENTRY_PERCPU (GDT_ENTRY_KERNEL_BASE+15)
103#ifdef CONFIG_SMP 141#ifdef CONFIG_SMP
104#define __KERNEL_PERCPU (GDT_ENTRY_PERCPU * 8) 142# define __KERNEL_PERCPU (GDT_ENTRY_PERCPU*8)
105#else 143#else
106#define __KERNEL_PERCPU 0 144# define __KERNEL_PERCPU 0
107#endif 145#endif
108 146
109#define GDT_ENTRY_STACK_CANARY (GDT_ENTRY_KERNEL_BASE+16)
110#ifdef CONFIG_CC_STACKPROTECTOR 147#ifdef CONFIG_CC_STACKPROTECTOR
111#define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY*8) 148# define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY*8)
112#else 149#else
113#define __KERNEL_STACK_CANARY 0 150# define __KERNEL_STACK_CANARY 0
114#endif 151#endif
115 152
116#define GDT_ENTRY_DOUBLEFAULT_TSS 31 153#else /* 64-bit: */
117
118/*
119 * The GDT has 32 entries
120 */
121#define GDT_ENTRIES 32
122 154
123/* The PnP BIOS entries in the GDT */ 155#include <asm/cache.h>
124#define GDT_ENTRY_PNPBIOS_CS32 (GDT_ENTRY_PNPBIOS_BASE + 0)
125#define GDT_ENTRY_PNPBIOS_CS16 (GDT_ENTRY_PNPBIOS_BASE + 1)
126#define GDT_ENTRY_PNPBIOS_DS (GDT_ENTRY_PNPBIOS_BASE + 2)
127#define GDT_ENTRY_PNPBIOS_TS1 (GDT_ENTRY_PNPBIOS_BASE + 3)
128#define GDT_ENTRY_PNPBIOS_TS2 (GDT_ENTRY_PNPBIOS_BASE + 4)
129
130/* The PnP BIOS selectors */
131#define PNP_CS32 (GDT_ENTRY_PNPBIOS_CS32 * 8) /* segment for calling fn */
132#define PNP_CS16 (GDT_ENTRY_PNPBIOS_CS16 * 8) /* code segment for BIOS */
133#define PNP_DS (GDT_ENTRY_PNPBIOS_DS * 8) /* data segment for BIOS */
134#define PNP_TS1 (GDT_ENTRY_PNPBIOS_TS1 * 8) /* transfer data segment */
135#define PNP_TS2 (GDT_ENTRY_PNPBIOS_TS2 * 8) /* another data segment */
136 156
157#define GDT_ENTRY_KERNEL32_CS 1
158#define GDT_ENTRY_KERNEL_CS 2
159#define GDT_ENTRY_KERNEL_DS 3
137 160
138/* 161/*
139 * Matching rules for certain types of segments. 162 * We cannot use the same code segment descriptor for user and kernel mode,
163 * not even in long flat mode, because of different DPL.
164 *
165 * GDT layout to get 64-bit SYSCALL/SYSRET support right. SYSRET hardcodes
166 * selectors:
167 *
168 * if returning to 32-bit userspace: cs = STAR.SYSRET_CS,
169 * if returning to 64-bit userspace: cs = STAR.SYSRET_CS+16,
170 *
171 * ss = STAR.SYSRET_CS+8 (in either case)
172 *
173 * thus USER_DS should be between 32-bit and 64-bit code selectors:
140 */ 174 */
175#define GDT_ENTRY_DEFAULT_USER32_CS 4
176#define GDT_ENTRY_DEFAULT_USER_DS 5
177#define GDT_ENTRY_DEFAULT_USER_CS 6
141 178
142/* Matches PNP_CS32 and PNP_CS16 (they must be consecutive) */ 179/* Needs two entries */
143#define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == GDT_ENTRY_PNPBIOS_BASE * 8) 180#define GDT_ENTRY_TSS 8
144 181/* Needs two entries */
182#define GDT_ENTRY_LDT 10
145 183
146#else 184#define GDT_ENTRY_TLS_MIN 12
147#include <asm/cache.h> 185#define GDT_ENTRY_TLS_MAX 14
148
149#define GDT_ENTRY_KERNEL32_CS 1
150#define GDT_ENTRY_KERNEL_CS 2
151#define GDT_ENTRY_KERNEL_DS 3
152 186
153#define __KERNEL32_CS (GDT_ENTRY_KERNEL32_CS * 8) 187/* Abused to load per CPU data from limit */
188#define GDT_ENTRY_PER_CPU 15
154 189
155/* 190/*
156 * we cannot use the same code segment descriptor for user and kernel 191 * Number of entries in the GDT table:
157 * -- not even in the long flat mode, because of different DPL /kkeil
158 * The segment offset needs to contain a RPL. Grr. -AK
159 * GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)
160 */ 192 */
161#define GDT_ENTRY_DEFAULT_USER32_CS 4 193#define GDT_ENTRIES 16
162#define GDT_ENTRY_DEFAULT_USER_DS 5
163#define GDT_ENTRY_DEFAULT_USER_CS 6
164#define __USER32_CS (GDT_ENTRY_DEFAULT_USER32_CS*8+3)
165#define __USER32_DS __USER_DS
166
167#define GDT_ENTRY_TSS 8 /* needs two entries */
168#define GDT_ENTRY_LDT 10 /* needs two entries */
169#define GDT_ENTRY_TLS_MIN 12
170#define GDT_ENTRY_TLS_MAX 14
171
172#define GDT_ENTRY_PER_CPU 15 /* Abused to load per CPU data from limit */
173#define __PER_CPU_SEG (GDT_ENTRY_PER_CPU * 8 + 3)
174 194
175/* TLS indexes for 64bit - hardcoded in arch_prctl */ 195/*
176#define FS_TLS 0 196 * Segment selector values corresponding to the above entries:
177#define GS_TLS 1 197 *
178 198 * Note, selectors also need to have a correct RPL,
179#define GS_TLS_SEL ((GDT_ENTRY_TLS_MIN+GS_TLS)*8 + 3) 199 * expressed with the +3 value for user-space selectors:
180#define FS_TLS_SEL ((GDT_ENTRY_TLS_MIN+FS_TLS)*8 + 3) 200 */
181 201#define __KERNEL32_CS (GDT_ENTRY_KERNEL32_CS*8)
182#define GDT_ENTRIES 16 202#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8)
203#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
204#define __USER32_CS (GDT_ENTRY_DEFAULT_USER32_CS*8 + 3)
205#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
206#define __USER32_DS __USER_DS
207#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
208#define __PER_CPU_SEG (GDT_ENTRY_PER_CPU*8 + 3)
209
210/* TLS indexes for 64-bit - hardcoded in arch_prctl(): */
211#define FS_TLS 0
212#define GS_TLS 1
213
214#define GS_TLS_SEL ((GDT_ENTRY_TLS_MIN+GS_TLS)*8 + 3)
215#define FS_TLS_SEL ((GDT_ENTRY_TLS_MIN+FS_TLS)*8 + 3)
183 216
184#endif 217#endif
185 218
186#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8)
187#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
188#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8+3)
189#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8+3)
190#ifndef CONFIG_PARAVIRT 219#ifndef CONFIG_PARAVIRT
191#define get_kernel_rpl() 0 220# define get_kernel_rpl() 0
192#endif 221#endif
193 222
194#define IDT_ENTRIES 256 223#define IDT_ENTRIES 256
195#define NUM_EXCEPTION_VECTORS 32 224#define NUM_EXCEPTION_VECTORS 32
196/* Bitmask of exception vectors which push an error code on the stack */ 225
197#define EXCEPTION_ERRCODE_MASK 0x00027d00 226/* Bitmask of exception vectors which push an error code on the stack: */
198#define GDT_SIZE (GDT_ENTRIES * 8) 227#define EXCEPTION_ERRCODE_MASK 0x00027d00
199#define GDT_ENTRY_TLS_ENTRIES 3 228
200#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8) 229#define GDT_SIZE (GDT_ENTRIES*8)
230#define GDT_ENTRY_TLS_ENTRIES 3
231#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES* 8)
201 232
202#ifdef __KERNEL__ 233#ifdef __KERNEL__
203#ifndef __ASSEMBLY__ 234#ifndef __ASSEMBLY__
235
204extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][2+2+5]; 236extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][2+2+5];
205#ifdef CONFIG_TRACING 237#ifdef CONFIG_TRACING
206#define trace_early_idt_handlers early_idt_handlers 238# define trace_early_idt_handlers early_idt_handlers
207#endif 239#endif
208 240
209/* 241/*
@@ -228,37 +260,30 @@ do { \
228} while (0) 260} while (0)
229 261
230/* 262/*
231 * Save a segment register away 263 * Save a segment register away:
232 */ 264 */
233#define savesegment(seg, value) \ 265#define savesegment(seg, value) \
234 asm("mov %%" #seg ",%0":"=r" (value) : : "memory") 266 asm("mov %%" #seg ",%0":"=r" (value) : : "memory")
235 267
236/* 268/*
237 * x86_32 user gs accessors. 269 * x86-32 user GS accessors:
238 */ 270 */
239#ifdef CONFIG_X86_32 271#ifdef CONFIG_X86_32
240#ifdef CONFIG_X86_32_LAZY_GS 272# ifdef CONFIG_X86_32_LAZY_GS
241#define get_user_gs(regs) (u16)({unsigned long v; savesegment(gs, v); v;}) 273# define get_user_gs(regs) (u16)({ unsigned long v; savesegment(gs, v); v; })
242#define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v)) 274# define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v))
243#define task_user_gs(tsk) ((tsk)->thread.gs) 275# define task_user_gs(tsk) ((tsk)->thread.gs)
244#define lazy_save_gs(v) savesegment(gs, (v)) 276# define lazy_save_gs(v) savesegment(gs, (v))
245#define lazy_load_gs(v) loadsegment(gs, (v)) 277# define lazy_load_gs(v) loadsegment(gs, (v))
246#else /* X86_32_LAZY_GS */ 278# else /* X86_32_LAZY_GS */
247#define get_user_gs(regs) (u16)((regs)->gs) 279# define get_user_gs(regs) (u16)((regs)->gs)
248#define set_user_gs(regs, v) do { (regs)->gs = (v); } while (0) 280# define set_user_gs(regs, v) do { (regs)->gs = (v); } while (0)
249#define task_user_gs(tsk) (task_pt_regs(tsk)->gs) 281# define task_user_gs(tsk) (task_pt_regs(tsk)->gs)
250#define lazy_save_gs(v) do { } while (0) 282# define lazy_save_gs(v) do { } while (0)
251#define lazy_load_gs(v) do { } while (0) 283# define lazy_load_gs(v) do { } while (0)
252#endif /* X86_32_LAZY_GS */ 284# endif /* X86_32_LAZY_GS */
253#endif /* X86_32 */ 285#endif /* X86_32 */
254 286
255static inline unsigned long get_limit(unsigned long segment)
256{
257 unsigned long __limit;
258 asm("lsll %1,%0" : "=r" (__limit) : "r" (segment));
259 return __limit + 1;
260}
261
262#endif /* !__ASSEMBLY__ */ 287#endif /* !__ASSEMBLY__ */
263#endif /* __KERNEL__ */ 288#endif /* __KERNEL__ */
264 289
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