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 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 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 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 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 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) 107 108 static inline void paravirt_alloc_ldt(struct desc_struct *ldt, unsigned entries) 109 { 110 } 111 112 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)) 118 119 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 } 123 124 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 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 } 142 143 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 } 153 154 155 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 } 174 175 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) 194 195 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 } 210 211 static inline void native_load_tr_desc(void) 212 { 213 asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8)); 214 } 215 216 static inline void native_load_gdt(const struct desc_ptr *dtr) 217 { 218 asm volatile("lgdt %0"::"m" (*dtr)); 219 } 220 221 static inline void native_load_idt(const struct desc_ptr *dtr) 222 { 223 asm volatile("lidt %0"::"m" (*dtr)); 224 } 225 226 static inline void native_store_gdt(struct desc_ptr *dtr) 227 { 228 asm volatile("sgdt %0":"=m" (*dtr)); 229 } 230 231 static inline void native_store_idt(struct desc_ptr *dtr) 232 { 233 asm volatile("sidt %0":"=m" (*dtr)); 234 } 235 236 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 } 244 245 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". */ 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 } 277 278 static inline void clear_LDT(void) 279 { 280 set_ldt(NULL, 0); 281 } 282 283 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 } 287 288 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 } 294 295 static inline unsigned long get_desc_limit(const struct desc_struct *desc) 296 { 297 return desc->limit0 | (desc->limit << 16); 298 } 299 300 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_64 307 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[]; 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 } 323 324 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 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 343 344 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_notrace(n, addr) \ 365 do { \ 366 BUG_ON((unsigned)n > 0xFF); \ 367 _set_gate(n, GATE_INTERRUPT, (void *)addr, 0, 0, \ 368 __KERNEL_CS); \ 369 } while (0) 370 371 #define set_intr_gate(n, addr) \ 372 do { \ 373 set_intr_gate_notrace(n, addr); \ 374 _trace_set_gate(n, GATE_INTERRUPT, (void *)trace_##addr,\ 375 0, 0, __KERNEL_CS); \ 376 } while (0) 377 378 extern int first_system_vector; 379 /* used_vectors is BITMAP for irq is not managed by percpu vector_irq */ 380 extern unsigned long used_vectors[]; 381 382 static inline void alloc_system_vector(int vector) 383 { 384 if (!test_bit(vector, used_vectors)) { 385 set_bit(vector, used_vectors); 386 if (first_system_vector > vector) 387 first_system_vector = vector; 388 } else { 389 BUG(); 390 } 391 } 392 393 #define alloc_intr_gate(n, addr) \ 394 do { \ 395 alloc_system_vector(n); \ 396 set_intr_gate(n, addr); \ 397 } while (0) 398 399 /* 400 * This routine sets up an interrupt gate at directory privilege level 3. 401 */ 402 static inline void set_system_intr_gate(unsigned int n, void *addr) 403 { 404 BUG_ON((unsigned)n > 0xFF); 405 _set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS); 406 } 407 408 static inline void set_system_trap_gate(unsigned int n, void *addr) 409 { 410 BUG_ON((unsigned)n > 0xFF); 411 _set_gate(n, GATE_TRAP, addr, 0x3, 0, __KERNEL_CS); 412 } 413 414 static inline void set_trap_gate(unsigned int n, void *addr) 415 { 416 BUG_ON((unsigned)n > 0xFF); 417 _set_gate(n, GATE_TRAP, addr, 0, 0, __KERNEL_CS); 418 } 419 420 static inline void set_task_gate(unsigned int n, unsigned int gdt_entry) 421 { 422 BUG_ON((unsigned)n > 0xFF); 423 _set_gate(n, GATE_TASK, (void *)0, 0, 0, (gdt_entry<<3)); 424 } 425 426 static inline void set_intr_gate_ist(int n, void *addr, unsigned ist) 427 { 428 BUG_ON((unsigned)n > 0xFF); 429 _set_gate(n, GATE_INTERRUPT, addr, 0, ist, __KERNEL_CS); 430 } 431 432 static inline void set_system_intr_gate_ist(int n, void *addr, unsigned ist) 433 { 434 BUG_ON((unsigned)n > 0xFF); 435 _set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS); 436 } 437 438 #ifdef CONFIG_X86_64 439 DECLARE_PER_CPU(u32, debug_idt_ctr); 440 static inline bool is_debug_idt_enabled(void) 441 { 442 if (this_cpu_read(debug_idt_ctr)) 443 return true; 444 445 return false; 446 } 447 448 static inline void load_debug_idt(void) 449 { 450 load_idt((const struct desc_ptr *)&debug_idt_descr); 451 } 452 #else 453 static inline bool is_debug_idt_enabled(void) 454 { 455 return false; 456 } 457 458 static inline void load_debug_idt(void) 459 { 460 } 461 #endif 462 463 #ifdef CONFIG_TRACING 464 extern atomic_t trace_idt_ctr; 465 static inline bool is_trace_idt_enabled(void) 466 { 467 if (atomic_read(&trace_idt_ctr)) 468 return true; 469 470 return false; 471 } 472 473 static inline void load_trace_idt(void) 474 { 475 load_idt((const struct desc_ptr *)&trace_idt_descr); 476 } 477 #else 478 static inline bool is_trace_idt_enabled(void) 479 { 480 return false; 481 } 482 483 static inline void load_trace_idt(void) 484 { 485 } 486 #endif 487 488 /* 489 * The load_current_idt() must be called with interrupts disabled 490 * to avoid races. That way the IDT will always be set back to the expected 491 * descriptor. It's also called when a CPU is being initialized, and 492 * that doesn't need to disable interrupts, as nothing should be 493 * bothering the CPU then. 494 */ 495 static inline void load_current_idt(void) 496 { 497 if (is_debug_idt_enabled()) 498 load_debug_idt(); 499 else if (is_trace_idt_enabled()) 500 load_trace_idt(); 501 else 502 load_idt((const struct desc_ptr *)&idt_descr); 503 } 504 #endif /* _ASM_X86_DESC_H */ 505