1 #ifndef _ASM_X86_DESC_H
2 #define _ASM_X86_DESC_H
3
4 #ifndef __ASSEMBLY__
5 #include <asm/desc_defs.h>
6 #include <asm/ldt.h>
7 #include <asm/mmu.h>
8 #include <linux/smp.h>
9
fill_ldt(struct desc_struct * desc,const struct user_desc * info)10 static inline void fill_ldt(struct desc_struct *desc,
11 const struct user_desc *info)
12 {
13 desc->limit0 = info->limit & 0x0ffff;
14 desc->base0 = info->base_addr & 0x0000ffff;
15
16 desc->base1 = (info->base_addr & 0x00ff0000) >> 16;
17 desc->type = (info->read_exec_only ^ 1) << 1;
18 desc->type |= info->contents << 2;
19 desc->s = 1;
20 desc->dpl = 0x3;
21 desc->p = info->seg_not_present ^ 1;
22 desc->limit = (info->limit & 0xf0000) >> 16;
23 desc->avl = info->useable;
24 desc->d = info->seg_32bit;
25 desc->g = info->limit_in_pages;
26 desc->base2 = (info->base_addr & 0xff000000) >> 24;
27 /*
28 * Don't allow setting of the lm bit. It is useless anyway
29 * because 64bit system calls require __USER_CS:
30 */
31 desc->l = 0;
32 }
33
34 extern struct desc_ptr idt_descr;
35 extern gate_desc idt_table[];
36
37 struct gdt_page {
38 struct desc_struct gdt[GDT_ENTRIES];
39 } __attribute__((aligned(PAGE_SIZE)));
40 DECLARE_PER_CPU(struct gdt_page, gdt_page);
41
get_cpu_gdt_table(unsigned int cpu)42 static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu)
43 {
44 return per_cpu(gdt_page, cpu).gdt;
45 }
46
47 #ifdef CONFIG_X86_64
48
pack_gate(gate_desc * gate,unsigned type,unsigned long func,unsigned dpl,unsigned ist,unsigned seg)49 static inline void pack_gate(gate_desc *gate, unsigned type, unsigned long func,
50 unsigned dpl, unsigned ist, unsigned seg)
51 {
52 gate->offset_low = PTR_LOW(func);
53 gate->segment = __KERNEL_CS;
54 gate->ist = ist;
55 gate->p = 1;
56 gate->dpl = dpl;
57 gate->zero0 = 0;
58 gate->zero1 = 0;
59 gate->type = type;
60 gate->offset_middle = PTR_MIDDLE(func);
61 gate->offset_high = PTR_HIGH(func);
62 }
63
64 #else
pack_gate(gate_desc * gate,unsigned char type,unsigned long base,unsigned dpl,unsigned flags,unsigned short seg)65 static inline void pack_gate(gate_desc *gate, unsigned char type,
66 unsigned long base, unsigned dpl, unsigned flags,
67 unsigned short seg)
68 {
69 gate->a = (seg << 16) | (base & 0xffff);
70 gate->b = (base & 0xffff0000) |
71 (((0x80 | type | (dpl << 5)) & 0xff) << 8);
72 }
73
74 #endif
75
desc_empty(const void * ptr)76 static inline int desc_empty(const void *ptr)
77 {
78 const u32 *desc = ptr;
79 return !(desc[0] | desc[1]);
80 }
81
82 #ifdef CONFIG_PARAVIRT
83 #include <asm/paravirt.h>
84 #else
85 #define load_TR_desc() native_load_tr_desc()
86 #define load_gdt(dtr) native_load_gdt(dtr)
87 #define load_idt(dtr) native_load_idt(dtr)
88 #define load_tr(tr) asm volatile("ltr %0"::"m" (tr))
89 #define load_ldt(ldt) asm volatile("lldt %0"::"m" (ldt))
90
91 #define store_gdt(dtr) native_store_gdt(dtr)
92 #define store_idt(dtr) native_store_idt(dtr)
93 #define store_tr(tr) (tr = native_store_tr())
94 #define store_ldt(ldt) asm("sldt %0":"=m" (ldt))
95
96 #define load_TLS(t, cpu) native_load_tls(t, cpu)
97 #define set_ldt native_set_ldt
98
99 #define write_ldt_entry(dt, entry, desc) \
100 native_write_ldt_entry(dt, entry, desc)
101 #define write_gdt_entry(dt, entry, desc, type) \
102 native_write_gdt_entry(dt, entry, desc, type)
103 #define write_idt_entry(dt, entry, g) \
104 native_write_idt_entry(dt, entry, g)
105
paravirt_alloc_ldt(struct desc_struct * ldt,unsigned entries)106 static inline void paravirt_alloc_ldt(struct desc_struct *ldt, unsigned entries)
107 {
108 }
109
paravirt_free_ldt(struct desc_struct * ldt,unsigned entries)110 static inline void paravirt_free_ldt(struct desc_struct *ldt, unsigned entries)
111 {
112 }
113 #endif /* CONFIG_PARAVIRT */
114
native_write_idt_entry(gate_desc * idt,int entry,const gate_desc * gate)115 static inline void native_write_idt_entry(gate_desc *idt, int entry,
116 const gate_desc *gate)
117 {
118 memcpy(&idt[entry], gate, sizeof(*gate));
119 }
120
native_write_ldt_entry(struct desc_struct * ldt,int entry,const void * desc)121 static inline void native_write_ldt_entry(struct desc_struct *ldt, int entry,
122 const void *desc)
123 {
124 memcpy(&ldt[entry], desc, 8);
125 }
126
native_write_gdt_entry(struct desc_struct * gdt,int entry,const void * desc,int type)127 static inline void native_write_gdt_entry(struct desc_struct *gdt, int entry,
128 const void *desc, int type)
129 {
130 unsigned int size;
131 switch (type) {
132 case DESC_TSS:
133 size = sizeof(tss_desc);
134 break;
135 case DESC_LDT:
136 size = sizeof(ldt_desc);
137 break;
138 default:
139 size = sizeof(struct desc_struct);
140 break;
141 }
142 memcpy(&gdt[entry], desc, size);
143 }
144
pack_descriptor(struct desc_struct * desc,unsigned long base,unsigned long limit,unsigned char type,unsigned char flags)145 static inline void pack_descriptor(struct desc_struct *desc, unsigned long base,
146 unsigned long limit, unsigned char type,
147 unsigned char flags)
148 {
149 desc->a = ((base & 0xffff) << 16) | (limit & 0xffff);
150 desc->b = (base & 0xff000000) | ((base & 0xff0000) >> 16) |
151 (limit & 0x000f0000) | ((type & 0xff) << 8) |
152 ((flags & 0xf) << 20);
153 desc->p = 1;
154 }
155
156
set_tssldt_descriptor(void * d,unsigned long addr,unsigned type,unsigned size)157 static inline void set_tssldt_descriptor(void *d, unsigned long addr,
158 unsigned type, unsigned size)
159 {
160 #ifdef CONFIG_X86_64
161 struct ldttss_desc64 *desc = d;
162 memset(desc, 0, sizeof(*desc));
163 desc->limit0 = size & 0xFFFF;
164 desc->base0 = PTR_LOW(addr);
165 desc->base1 = PTR_MIDDLE(addr) & 0xFF;
166 desc->type = type;
167 desc->p = 1;
168 desc->limit1 = (size >> 16) & 0xF;
169 desc->base2 = (PTR_MIDDLE(addr) >> 8) & 0xFF;
170 desc->base3 = PTR_HIGH(addr);
171 #else
172 pack_descriptor((struct desc_struct *)d, addr, size, 0x80 | type, 0);
173 #endif
174 }
175
__set_tss_desc(unsigned cpu,unsigned int entry,void * addr)176 static inline void __set_tss_desc(unsigned cpu, unsigned int entry, void *addr)
177 {
178 struct desc_struct *d = get_cpu_gdt_table(cpu);
179 tss_desc tss;
180
181 /*
182 * sizeof(unsigned long) coming from an extra "long" at the end
183 * of the iobitmap. See tss_struct definition in processor.h
184 *
185 * -1? seg base+limit should be pointing to the address of the
186 * last valid byte
187 */
188 set_tssldt_descriptor(&tss, (unsigned long)addr, DESC_TSS,
189 IO_BITMAP_OFFSET + IO_BITMAP_BYTES +
190 sizeof(unsigned long) - 1);
191 write_gdt_entry(d, entry, &tss, DESC_TSS);
192 }
193
194 #define set_tss_desc(cpu, addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
195
native_set_ldt(const void * addr,unsigned int entries)196 static inline void native_set_ldt(const void *addr, unsigned int entries)
197 {
198 if (likely(entries == 0))
199 asm volatile("lldt %w0"::"q" (0));
200 else {
201 unsigned cpu = smp_processor_id();
202 ldt_desc ldt;
203
204 set_tssldt_descriptor(&ldt, (unsigned long)addr, DESC_LDT,
205 entries * LDT_ENTRY_SIZE - 1);
206 write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT,
207 &ldt, DESC_LDT);
208 asm volatile("lldt %w0"::"q" (GDT_ENTRY_LDT*8));
209 }
210 }
211
native_load_tr_desc(void)212 static inline void native_load_tr_desc(void)
213 {
214 asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8));
215 }
216
native_load_gdt(const struct desc_ptr * dtr)217 static inline void native_load_gdt(const struct desc_ptr *dtr)
218 {
219 asm volatile("lgdt %0"::"m" (*dtr));
220 }
221
native_load_idt(const struct desc_ptr * dtr)222 static inline void native_load_idt(const struct desc_ptr *dtr)
223 {
224 asm volatile("lidt %0"::"m" (*dtr));
225 }
226
native_store_gdt(struct desc_ptr * dtr)227 static inline void native_store_gdt(struct desc_ptr *dtr)
228 {
229 asm volatile("sgdt %0":"=m" (*dtr));
230 }
231
native_store_idt(struct desc_ptr * dtr)232 static inline void native_store_idt(struct desc_ptr *dtr)
233 {
234 asm volatile("sidt %0":"=m" (*dtr));
235 }
236
native_store_tr(void)237 static inline unsigned long native_store_tr(void)
238 {
239 unsigned long tr;
240 asm volatile("str %0":"=r" (tr));
241 return tr;
242 }
243
native_load_tls(struct thread_struct * t,unsigned int cpu)244 static inline void native_load_tls(struct thread_struct *t, unsigned int cpu)
245 {
246 unsigned int i;
247 struct desc_struct *gdt = get_cpu_gdt_table(cpu);
248
249 for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++)
250 gdt[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i];
251 }
252
253 #define _LDT_empty(info) \
254 ((info)->base_addr == 0 && \
255 (info)->limit == 0 && \
256 (info)->contents == 0 && \
257 (info)->read_exec_only == 1 && \
258 (info)->seg_32bit == 0 && \
259 (info)->limit_in_pages == 0 && \
260 (info)->seg_not_present == 1 && \
261 (info)->useable == 0)
262
263 #ifdef CONFIG_X86_64
264 #define LDT_empty(info) (_LDT_empty(info) && ((info)->lm == 0))
265 #else
266 #define LDT_empty(info) (_LDT_empty(info))
267 #endif
268
clear_LDT(void)269 static inline void clear_LDT(void)
270 {
271 set_ldt(NULL, 0);
272 }
273
274 /*
275 * load one particular LDT into the current CPU
276 */
load_LDT_nolock(mm_context_t * pc)277 static inline void load_LDT_nolock(mm_context_t *pc)
278 {
279 set_ldt(pc->ldt, pc->size);
280 }
281
load_LDT(mm_context_t * pc)282 static inline void load_LDT(mm_context_t *pc)
283 {
284 preempt_disable();
285 load_LDT_nolock(pc);
286 preempt_enable();
287 }
288
get_desc_base(const struct desc_struct * desc)289 static inline unsigned long get_desc_base(const struct desc_struct *desc)
290 {
291 return desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24);
292 }
293
get_desc_limit(const struct desc_struct * desc)294 static inline unsigned long get_desc_limit(const struct desc_struct *desc)
295 {
296 return desc->limit0 | (desc->limit << 16);
297 }
298
_set_gate(int gate,unsigned type,void * addr,unsigned dpl,unsigned ist,unsigned seg)299 static inline void _set_gate(int gate, unsigned type, void *addr,
300 unsigned dpl, unsigned ist, unsigned seg)
301 {
302 gate_desc s;
303 pack_gate(&s, type, (unsigned long)addr, dpl, ist, seg);
304 /*
305 * does not need to be atomic because it is only done once at
306 * setup time
307 */
308 write_idt_entry(idt_table, gate, &s);
309 }
310
311 /*
312 * This needs to use 'idt_table' rather than 'idt', and
313 * thus use the _nonmapped_ version of the IDT, as the
314 * Pentium F0 0F bugfix can have resulted in the mapped
315 * IDT being write-protected.
316 */
set_intr_gate(unsigned int n,void * addr)317 static inline void set_intr_gate(unsigned int n, void *addr)
318 {
319 BUG_ON((unsigned)n > 0xFF);
320 _set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS);
321 }
322
323 extern int first_system_vector;
324 /* used_vectors is BITMAP for irq is not managed by percpu vector_irq */
325 extern unsigned long used_vectors[];
326
alloc_system_vector(int vector)327 static inline void alloc_system_vector(int vector)
328 {
329 if (!test_bit(vector, used_vectors)) {
330 set_bit(vector, used_vectors);
331 if (first_system_vector > vector)
332 first_system_vector = vector;
333 } else
334 BUG();
335 }
336
alloc_intr_gate(unsigned int n,void * addr)337 static inline void alloc_intr_gate(unsigned int n, void *addr)
338 {
339 alloc_system_vector(n);
340 set_intr_gate(n, addr);
341 }
342
343 /*
344 * This routine sets up an interrupt gate at directory privilege level 3.
345 */
set_system_intr_gate(unsigned int n,void * addr)346 static inline void set_system_intr_gate(unsigned int n, void *addr)
347 {
348 BUG_ON((unsigned)n > 0xFF);
349 _set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS);
350 }
351
set_system_trap_gate(unsigned int n,void * addr)352 static inline void set_system_trap_gate(unsigned int n, void *addr)
353 {
354 BUG_ON((unsigned)n > 0xFF);
355 _set_gate(n, GATE_TRAP, addr, 0x3, 0, __KERNEL_CS);
356 }
357
set_trap_gate(unsigned int n,void * addr)358 static inline void set_trap_gate(unsigned int n, void *addr)
359 {
360 BUG_ON((unsigned)n > 0xFF);
361 _set_gate(n, GATE_TRAP, addr, 0, 0, __KERNEL_CS);
362 }
363
set_task_gate(unsigned int n,unsigned int gdt_entry)364 static inline void set_task_gate(unsigned int n, unsigned int gdt_entry)
365 {
366 BUG_ON((unsigned)n > 0xFF);
367 _set_gate(n, GATE_TASK, (void *)0, 0, 0, (gdt_entry<<3));
368 }
369
set_intr_gate_ist(int n,void * addr,unsigned ist)370 static inline void set_intr_gate_ist(int n, void *addr, unsigned ist)
371 {
372 BUG_ON((unsigned)n > 0xFF);
373 _set_gate(n, GATE_INTERRUPT, addr, 0, ist, __KERNEL_CS);
374 }
375
set_system_intr_gate_ist(int n,void * addr,unsigned ist)376 static inline void set_system_intr_gate_ist(int n, void *addr, unsigned ist)
377 {
378 BUG_ON((unsigned)n > 0xFF);
379 _set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS);
380 }
381
382 #else
383 /*
384 * GET_DESC_BASE reads the descriptor base of the specified segment.
385 *
386 * Args:
387 * idx - descriptor index
388 * gdt - GDT pointer
389 * base - 32bit register to which the base will be written
390 * lo_w - lo word of the "base" register
391 * lo_b - lo byte of the "base" register
392 * hi_b - hi byte of the low word of the "base" register
393 *
394 * Example:
395 * GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah)
396 * Will read the base address of GDT_ENTRY_ESPFIX_SS and put it into %eax.
397 */
398 #define GET_DESC_BASE(idx, gdt, base, lo_w, lo_b, hi_b) \
399 movb idx * 8 + 4(gdt), lo_b; \
400 movb idx * 8 + 7(gdt), hi_b; \
401 shll $16, base; \
402 movw idx * 8 + 2(gdt), lo_w;
403
404
405 #endif /* __ASSEMBLY__ */
406
407 #endif /* _ASM_X86_DESC_H */
408