1 #ifndef _ASM_X86_DESC_H
2 #define _ASM_X86_DESC_H
3
4 #include <asm/desc_defs.h>
5 #include <asm/ldt.h>
6 #include <asm/mmu.h>
7
8 #include <linux/smp.h>
9 #include <linux/percpu.h>
10
fill_ldt(struct desc_struct * desc,const struct user_desc * info)11 static inline void fill_ldt(struct desc_struct *desc, const struct user_desc *info)
12 {
13 desc->limit0 = info->limit & 0x0ffff;
14
15 desc->base0 = (info->base_addr & 0x0000ffff);
16 desc->base1 = (info->base_addr & 0x00ff0000) >> 16;
17
18 desc->type = (info->read_exec_only ^ 1) << 1;
19 desc->type |= info->contents << 2;
20
21 desc->s = 1;
22 desc->dpl = 0x3;
23 desc->p = info->seg_not_present ^ 1;
24 desc->limit = (info->limit & 0xf0000) >> 16;
25 desc->avl = info->useable;
26 desc->d = info->seg_32bit;
27 desc->g = info->limit_in_pages;
28
29 desc->base2 = (info->base_addr & 0xff000000) >> 24;
30 /*
31 * Don't allow setting of the lm bit. It would confuse
32 * user_64bit_mode and would get overridden by sysret anyway.
33 */
34 desc->l = 0;
35 }
36
37 extern struct desc_ptr idt_descr;
38 extern gate_desc idt_table[];
39 extern struct desc_ptr debug_idt_descr;
40 extern gate_desc debug_idt_table[];
41
42 struct gdt_page {
43 struct desc_struct gdt[GDT_ENTRIES];
44 } __attribute__((aligned(PAGE_SIZE)));
45
46 DECLARE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page);
47
get_cpu_gdt_table(unsigned int cpu)48 static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu)
49 {
50 return per_cpu(gdt_page, cpu).gdt;
51 }
52
53 #ifdef CONFIG_X86_64
54
pack_gate(gate_desc * gate,unsigned type,unsigned long func,unsigned dpl,unsigned ist,unsigned seg)55 static inline void pack_gate(gate_desc *gate, unsigned type, unsigned long func,
56 unsigned dpl, unsigned ist, unsigned seg)
57 {
58 gate->offset_low = PTR_LOW(func);
59 gate->segment = __KERNEL_CS;
60 gate->ist = ist;
61 gate->p = 1;
62 gate->dpl = dpl;
63 gate->zero0 = 0;
64 gate->zero1 = 0;
65 gate->type = type;
66 gate->offset_middle = PTR_MIDDLE(func);
67 gate->offset_high = PTR_HIGH(func);
68 }
69
70 #else
pack_gate(gate_desc * gate,unsigned char type,unsigned long base,unsigned dpl,unsigned flags,unsigned short seg)71 static inline void pack_gate(gate_desc *gate, unsigned char type,
72 unsigned long base, unsigned dpl, unsigned flags,
73 unsigned short seg)
74 {
75 gate->a = (seg << 16) | (base & 0xffff);
76 gate->b = (base & 0xffff0000) | (((0x80 | type | (dpl << 5)) & 0xff) << 8);
77 }
78
79 #endif
80
desc_empty(const void * ptr)81 static inline int desc_empty(const void *ptr)
82 {
83 const u32 *desc = ptr;
84
85 return !(desc[0] | desc[1]);
86 }
87
88 #ifdef CONFIG_PARAVIRT
89 #include <asm/paravirt.h>
90 #else
91 #define load_TR_desc() native_load_tr_desc()
92 #define load_gdt(dtr) native_load_gdt(dtr)
93 #define load_idt(dtr) native_load_idt(dtr)
94 #define load_tr(tr) asm volatile("ltr %0"::"m" (tr))
95 #define load_ldt(ldt) asm volatile("lldt %0"::"m" (ldt))
96
97 #define store_gdt(dtr) native_store_gdt(dtr)
98 #define store_idt(dtr) native_store_idt(dtr)
99 #define store_tr(tr) (tr = native_store_tr())
100
101 #define load_TLS(t, cpu) native_load_tls(t, cpu)
102 #define set_ldt native_set_ldt
103
104 #define write_ldt_entry(dt, entry, desc) native_write_ldt_entry(dt, entry, desc)
105 #define write_gdt_entry(dt, entry, desc, type) native_write_gdt_entry(dt, entry, desc, type)
106 #define write_idt_entry(dt, entry, g) native_write_idt_entry(dt, entry, g)
107
paravirt_alloc_ldt(struct desc_struct * ldt,unsigned entries)108 static inline void paravirt_alloc_ldt(struct desc_struct *ldt, unsigned entries)
109 {
110 }
111
paravirt_free_ldt(struct desc_struct * ldt,unsigned entries)112 static inline void paravirt_free_ldt(struct desc_struct *ldt, unsigned entries)
113 {
114 }
115 #endif /* CONFIG_PARAVIRT */
116
117 #define store_ldt(ldt) asm("sldt %0" : "=m"(ldt))
118
native_write_idt_entry(gate_desc * idt,int entry,const gate_desc * gate)119 static inline void native_write_idt_entry(gate_desc *idt, int entry, const gate_desc *gate)
120 {
121 memcpy(&idt[entry], gate, sizeof(*gate));
122 }
123
native_write_ldt_entry(struct desc_struct * ldt,int entry,const void * desc)124 static inline void native_write_ldt_entry(struct desc_struct *ldt, int entry, const void *desc)
125 {
126 memcpy(&ldt[entry], desc, 8);
127 }
128
129 static inline void
native_write_gdt_entry(struct desc_struct * gdt,int entry,const void * desc,int type)130 native_write_gdt_entry(struct desc_struct *gdt, int entry, const void *desc, int type)
131 {
132 unsigned int size;
133
134 switch (type) {
135 case DESC_TSS: size = sizeof(tss_desc); break;
136 case DESC_LDT: size = sizeof(ldt_desc); break;
137 default: size = sizeof(*gdt); break;
138 }
139
140 memcpy(&gdt[entry], desc, size);
141 }
142
pack_descriptor(struct desc_struct * desc,unsigned long base,unsigned long limit,unsigned char type,unsigned char flags)143 static inline void pack_descriptor(struct desc_struct *desc, unsigned long base,
144 unsigned long limit, unsigned char type,
145 unsigned char flags)
146 {
147 desc->a = ((base & 0xffff) << 16) | (limit & 0xffff);
148 desc->b = (base & 0xff000000) | ((base & 0xff0000) >> 16) |
149 (limit & 0x000f0000) | ((type & 0xff) << 8) |
150 ((flags & 0xf) << 20);
151 desc->p = 1;
152 }
153
154
set_tssldt_descriptor(void * d,unsigned long addr,unsigned type,unsigned size)155 static inline void set_tssldt_descriptor(void *d, unsigned long addr, unsigned type, unsigned size)
156 {
157 #ifdef CONFIG_X86_64
158 struct ldttss_desc64 *desc = d;
159
160 memset(desc, 0, sizeof(*desc));
161
162 desc->limit0 = size & 0xFFFF;
163 desc->base0 = PTR_LOW(addr);
164 desc->base1 = PTR_MIDDLE(addr) & 0xFF;
165 desc->type = type;
166 desc->p = 1;
167 desc->limit1 = (size >> 16) & 0xF;
168 desc->base2 = (PTR_MIDDLE(addr) >> 8) & 0xFF;
169 desc->base3 = PTR_HIGH(addr);
170 #else
171 pack_descriptor((struct desc_struct *)d, addr, size, 0x80 | type, 0);
172 #endif
173 }
174
__set_tss_desc(unsigned cpu,unsigned int entry,void * addr)175 static inline void __set_tss_desc(unsigned cpu, unsigned int entry, void *addr)
176 {
177 struct desc_struct *d = get_cpu_gdt_table(cpu);
178 tss_desc tss;
179
180 /*
181 * sizeof(unsigned long) coming from an extra "long" at the end
182 * of the iobitmap. See tss_struct definition in processor.h
183 *
184 * -1? seg base+limit should be pointing to the address of the
185 * last valid byte
186 */
187 set_tssldt_descriptor(&tss, (unsigned long)addr, DESC_TSS,
188 IO_BITMAP_OFFSET + IO_BITMAP_BYTES +
189 sizeof(unsigned long) - 1);
190 write_gdt_entry(d, entry, &tss, DESC_TSS);
191 }
192
193 #define set_tss_desc(cpu, addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
194
native_set_ldt(const void * addr,unsigned int entries)195 static inline void native_set_ldt(const void *addr, unsigned int entries)
196 {
197 if (likely(entries == 0))
198 asm volatile("lldt %w0"::"q" (0));
199 else {
200 unsigned cpu = smp_processor_id();
201 ldt_desc ldt;
202
203 set_tssldt_descriptor(&ldt, (unsigned long)addr, DESC_LDT,
204 entries * LDT_ENTRY_SIZE - 1);
205 write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT,
206 &ldt, DESC_LDT);
207 asm volatile("lldt %w0"::"q" (GDT_ENTRY_LDT*8));
208 }
209 }
210
native_load_tr_desc(void)211 static inline void native_load_tr_desc(void)
212 {
213 asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8));
214 }
215
native_load_gdt(const struct desc_ptr * dtr)216 static inline void native_load_gdt(const struct desc_ptr *dtr)
217 {
218 asm volatile("lgdt %0"::"m" (*dtr));
219 }
220
native_load_idt(const struct desc_ptr * dtr)221 static inline void native_load_idt(const struct desc_ptr *dtr)
222 {
223 asm volatile("lidt %0"::"m" (*dtr));
224 }
225
native_store_gdt(struct desc_ptr * dtr)226 static inline void native_store_gdt(struct desc_ptr *dtr)
227 {
228 asm volatile("sgdt %0":"=m" (*dtr));
229 }
230
native_store_idt(struct desc_ptr * dtr)231 static inline void native_store_idt(struct desc_ptr *dtr)
232 {
233 asm volatile("sidt %0":"=m" (*dtr));
234 }
235
native_store_tr(void)236 static inline unsigned long native_store_tr(void)
237 {
238 unsigned long tr;
239
240 asm volatile("str %0":"=r" (tr));
241
242 return tr;
243 }
244
native_load_tls(struct thread_struct * t,unsigned int cpu)245 static inline void native_load_tls(struct thread_struct *t, unsigned int cpu)
246 {
247 struct desc_struct *gdt = get_cpu_gdt_table(cpu);
248 unsigned int i;
249
250 for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++)
251 gdt[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i];
252 }
253
254 /* This intentionally ignores lm, since 32-bit apps don't have that field. */
255 #define LDT_empty(info) \
256 ((info)->base_addr == 0 && \
257 (info)->limit == 0 && \
258 (info)->contents == 0 && \
259 (info)->read_exec_only == 1 && \
260 (info)->seg_32bit == 0 && \
261 (info)->limit_in_pages == 0 && \
262 (info)->seg_not_present == 1 && \
263 (info)->useable == 0)
264
265 /* Lots of programs expect an all-zero user_desc to mean "no segment at all". */
LDT_zero(const struct user_desc * info)266 static inline bool LDT_zero(const struct user_desc *info)
267 {
268 return (info->base_addr == 0 &&
269 info->limit == 0 &&
270 info->contents == 0 &&
271 info->read_exec_only == 0 &&
272 info->seg_32bit == 0 &&
273 info->limit_in_pages == 0 &&
274 info->seg_not_present == 0 &&
275 info->useable == 0);
276 }
277
clear_LDT(void)278 static inline void clear_LDT(void)
279 {
280 set_ldt(NULL, 0);
281 }
282
get_desc_base(const struct desc_struct * desc)283 static inline unsigned long get_desc_base(const struct desc_struct *desc)
284 {
285 return (unsigned)(desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24));
286 }
287
set_desc_base(struct desc_struct * desc,unsigned long base)288 static inline void set_desc_base(struct desc_struct *desc, unsigned long base)
289 {
290 desc->base0 = base & 0xffff;
291 desc->base1 = (base >> 16) & 0xff;
292 desc->base2 = (base >> 24) & 0xff;
293 }
294
get_desc_limit(const struct desc_struct * desc)295 static inline unsigned long get_desc_limit(const struct desc_struct *desc)
296 {
297 return desc->limit0 | (desc->limit << 16);
298 }
299
set_desc_limit(struct desc_struct * desc,unsigned long limit)300 static inline void set_desc_limit(struct desc_struct *desc, unsigned long limit)
301 {
302 desc->limit0 = limit & 0xffff;
303 desc->limit = (limit >> 16) & 0xf;
304 }
305
306 #ifdef CONFIG_X86_64
set_nmi_gate(int gate,void * addr)307 static inline void set_nmi_gate(int gate, void *addr)
308 {
309 gate_desc s;
310
311 pack_gate(&s, GATE_INTERRUPT, (unsigned long)addr, 0, 0, __KERNEL_CS);
312 write_idt_entry(debug_idt_table, gate, &s);
313 }
314 #endif
315
316 #ifdef CONFIG_TRACING
317 extern struct desc_ptr trace_idt_descr;
318 extern gate_desc trace_idt_table[];
write_trace_idt_entry(int entry,const gate_desc * gate)319 static inline void write_trace_idt_entry(int entry, const gate_desc *gate)
320 {
321 write_idt_entry(trace_idt_table, entry, gate);
322 }
323
_trace_set_gate(int gate,unsigned type,void * addr,unsigned dpl,unsigned ist,unsigned seg)324 static inline void _trace_set_gate(int gate, unsigned type, void *addr,
325 unsigned dpl, unsigned ist, unsigned seg)
326 {
327 gate_desc s;
328
329 pack_gate(&s, type, (unsigned long)addr, dpl, ist, seg);
330 /*
331 * does not need to be atomic because it is only done once at
332 * setup time
333 */
334 write_trace_idt_entry(gate, &s);
335 }
336 #else
write_trace_idt_entry(int entry,const gate_desc * gate)337 static inline void write_trace_idt_entry(int entry, const gate_desc *gate)
338 {
339 }
340
341 #define _trace_set_gate(gate, type, addr, dpl, ist, seg)
342 #endif
343
_set_gate(int gate,unsigned type,void * addr,unsigned dpl,unsigned ist,unsigned seg)344 static inline void _set_gate(int gate, unsigned type, void *addr,
345 unsigned dpl, unsigned ist, unsigned seg)
346 {
347 gate_desc s;
348
349 pack_gate(&s, type, (unsigned long)addr, dpl, ist, seg);
350 /*
351 * does not need to be atomic because it is only done once at
352 * setup time
353 */
354 write_idt_entry(idt_table, gate, &s);
355 write_trace_idt_entry(gate, &s);
356 }
357
358 /*
359 * This needs to use 'idt_table' rather than 'idt', and
360 * thus use the _nonmapped_ version of the IDT, as the
361 * Pentium F0 0F bugfix can have resulted in the mapped
362 * IDT being write-protected.
363 */
364 #define set_intr_gate(n, addr) \
365 do { \
366 BUG_ON((unsigned)n > 0xFF); \
367 _set_gate(n, GATE_INTERRUPT, (void *)addr, 0, 0, \
368 __KERNEL_CS); \
369 _trace_set_gate(n, GATE_INTERRUPT, (void *)trace_##addr,\
370 0, 0, __KERNEL_CS); \
371 } while (0)
372
373 extern int first_system_vector;
374 /* used_vectors is BITMAP for irq is not managed by percpu vector_irq */
375 extern unsigned long used_vectors[];
376
alloc_system_vector(int vector)377 static inline void alloc_system_vector(int vector)
378 {
379 if (!test_bit(vector, used_vectors)) {
380 set_bit(vector, used_vectors);
381 if (first_system_vector > vector)
382 first_system_vector = vector;
383 } else {
384 BUG();
385 }
386 }
387
388 #define alloc_intr_gate(n, addr) \
389 do { \
390 alloc_system_vector(n); \
391 set_intr_gate(n, addr); \
392 } while (0)
393
394 /*
395 * This routine sets up an interrupt gate at directory privilege level 3.
396 */
set_system_intr_gate(unsigned int n,void * addr)397 static inline void set_system_intr_gate(unsigned int n, void *addr)
398 {
399 BUG_ON((unsigned)n > 0xFF);
400 _set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS);
401 }
402
set_system_trap_gate(unsigned int n,void * addr)403 static inline void set_system_trap_gate(unsigned int n, void *addr)
404 {
405 BUG_ON((unsigned)n > 0xFF);
406 _set_gate(n, GATE_TRAP, addr, 0x3, 0, __KERNEL_CS);
407 }
408
set_trap_gate(unsigned int n,void * addr)409 static inline void set_trap_gate(unsigned int n, void *addr)
410 {
411 BUG_ON((unsigned)n > 0xFF);
412 _set_gate(n, GATE_TRAP, addr, 0, 0, __KERNEL_CS);
413 }
414
set_task_gate(unsigned int n,unsigned int gdt_entry)415 static inline void set_task_gate(unsigned int n, unsigned int gdt_entry)
416 {
417 BUG_ON((unsigned)n > 0xFF);
418 _set_gate(n, GATE_TASK, (void *)0, 0, 0, (gdt_entry<<3));
419 }
420
set_intr_gate_ist(int n,void * addr,unsigned ist)421 static inline void set_intr_gate_ist(int n, void *addr, unsigned ist)
422 {
423 BUG_ON((unsigned)n > 0xFF);
424 _set_gate(n, GATE_INTERRUPT, addr, 0, ist, __KERNEL_CS);
425 }
426
set_system_intr_gate_ist(int n,void * addr,unsigned ist)427 static inline void set_system_intr_gate_ist(int n, void *addr, unsigned ist)
428 {
429 BUG_ON((unsigned)n > 0xFF);
430 _set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS);
431 }
432
433 #ifdef CONFIG_X86_64
434 DECLARE_PER_CPU(u32, debug_idt_ctr);
is_debug_idt_enabled(void)435 static inline bool is_debug_idt_enabled(void)
436 {
437 if (this_cpu_read(debug_idt_ctr))
438 return true;
439
440 return false;
441 }
442
load_debug_idt(void)443 static inline void load_debug_idt(void)
444 {
445 load_idt((const struct desc_ptr *)&debug_idt_descr);
446 }
447 #else
is_debug_idt_enabled(void)448 static inline bool is_debug_idt_enabled(void)
449 {
450 return false;
451 }
452
load_debug_idt(void)453 static inline void load_debug_idt(void)
454 {
455 }
456 #endif
457
458 #ifdef CONFIG_TRACING
459 extern atomic_t trace_idt_ctr;
is_trace_idt_enabled(void)460 static inline bool is_trace_idt_enabled(void)
461 {
462 if (atomic_read(&trace_idt_ctr))
463 return true;
464
465 return false;
466 }
467
load_trace_idt(void)468 static inline void load_trace_idt(void)
469 {
470 load_idt((const struct desc_ptr *)&trace_idt_descr);
471 }
472 #else
is_trace_idt_enabled(void)473 static inline bool is_trace_idt_enabled(void)
474 {
475 return false;
476 }
477
load_trace_idt(void)478 static inline void load_trace_idt(void)
479 {
480 }
481 #endif
482
483 /*
484 * The load_current_idt() must be called with interrupts disabled
485 * to avoid races. That way the IDT will always be set back to the expected
486 * descriptor. It's also called when a CPU is being initialized, and
487 * that doesn't need to disable interrupts, as nothing should be
488 * bothering the CPU then.
489 */
load_current_idt(void)490 static inline void load_current_idt(void)
491 {
492 if (is_debug_idt_enabled())
493 load_debug_idt();
494 else if (is_trace_idt_enabled())
495 load_trace_idt();
496 else
497 load_idt((const struct desc_ptr *)&idt_descr);
498 }
499 #endif /* _ASM_X86_DESC_H */
500