1 /* 2 * linux/arch/x86_64/mm/init.c 3 * 4 * Copyright (C) 1995 Linus Torvalds 5 * Copyright (C) 2000 Pavel Machek <pavel@ucw.cz> 6 * Copyright (C) 2002,2003 Andi Kleen <ak@suse.de> 7 */ 8 9 #include <linux/signal.h> 10 #include <linux/sched.h> 11 #include <linux/kernel.h> 12 #include <linux/errno.h> 13 #include <linux/string.h> 14 #include <linux/types.h> 15 #include <linux/ptrace.h> 16 #include <linux/mman.h> 17 #include <linux/mm.h> 18 #include <linux/swap.h> 19 #include <linux/smp.h> 20 #include <linux/init.h> 21 #include <linux/initrd.h> 22 #include <linux/pagemap.h> 23 #include <linux/bootmem.h> 24 #include <linux/memblock.h> 25 #include <linux/proc_fs.h> 26 #include <linux/pci.h> 27 #include <linux/pfn.h> 28 #include <linux/poison.h> 29 #include <linux/dma-mapping.h> 30 #include <linux/module.h> 31 #include <linux/memory_hotplug.h> 32 #include <linux/nmi.h> 33 #include <linux/gfp.h> 34 35 #include <asm/processor.h> 36 #include <asm/bios_ebda.h> 37 #include <asm/system.h> 38 #include <asm/uaccess.h> 39 #include <asm/pgtable.h> 40 #include <asm/pgalloc.h> 41 #include <asm/dma.h> 42 #include <asm/fixmap.h> 43 #include <asm/e820.h> 44 #include <asm/apic.h> 45 #include <asm/tlb.h> 46 #include <asm/mmu_context.h> 47 #include <asm/proto.h> 48 #include <asm/smp.h> 49 #include <asm/sections.h> 50 #include <asm/kdebug.h> 51 #include <asm/numa.h> 52 #include <asm/cacheflush.h> 53 #include <asm/init.h> 54 55 static int __init parse_direct_gbpages_off(char *arg) 56 { 57 direct_gbpages = 0; 58 return 0; 59 } 60 early_param("nogbpages", parse_direct_gbpages_off); 61 62 static int __init parse_direct_gbpages_on(char *arg) 63 { 64 direct_gbpages = 1; 65 return 0; 66 } 67 early_param("gbpages", parse_direct_gbpages_on); 68 69 /* 70 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the 71 * physical space so we can cache the place of the first one and move 72 * around without checking the pgd every time. 73 */ 74 75 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP; 76 EXPORT_SYMBOL_GPL(__supported_pte_mask); 77 78 int force_personality32; 79 80 /* 81 * noexec32=on|off 82 * Control non executable heap for 32bit processes. 83 * To control the stack too use noexec=off 84 * 85 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default) 86 * off PROT_READ implies PROT_EXEC 87 */ 88 static int __init nonx32_setup(char *str) 89 { 90 if (!strcmp(str, "on")) 91 force_personality32 &= ~READ_IMPLIES_EXEC; 92 else if (!strcmp(str, "off")) 93 force_personality32 |= READ_IMPLIES_EXEC; 94 return 1; 95 } 96 __setup("noexec32=", nonx32_setup); 97 98 /* 99 * When memory was added/removed make sure all the processes MM have 100 * suitable PGD entries in the local PGD level page. 101 */ 102 void sync_global_pgds(unsigned long start, unsigned long end) 103 { 104 unsigned long address; 105 106 for (address = start; address <= end; address += PGDIR_SIZE) { 107 const pgd_t *pgd_ref = pgd_offset_k(address); 108 unsigned long flags; 109 struct page *page; 110 111 if (pgd_none(*pgd_ref)) 112 continue; 113 114 spin_lock_irqsave(&pgd_lock, flags); 115 list_for_each_entry(page, &pgd_list, lru) { 116 pgd_t *pgd; 117 spinlock_t *pgt_lock; 118 119 pgd = (pgd_t *)page_address(page) + pgd_index(address); 120 pgt_lock = &pgd_page_get_mm(page)->page_table_lock; 121 spin_lock(pgt_lock); 122 123 if (pgd_none(*pgd)) 124 set_pgd(pgd, *pgd_ref); 125 else 126 BUG_ON(pgd_page_vaddr(*pgd) 127 != pgd_page_vaddr(*pgd_ref)); 128 129 spin_unlock(pgt_lock); 130 } 131 spin_unlock_irqrestore(&pgd_lock, flags); 132 } 133 } 134 135 /* 136 * NOTE: This function is marked __ref because it calls __init function 137 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. 138 */ 139 static __ref void *spp_getpage(void) 140 { 141 void *ptr; 142 143 if (after_bootmem) 144 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 145 else 146 ptr = alloc_bootmem_pages(PAGE_SIZE); 147 148 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) { 149 panic("set_pte_phys: cannot allocate page data %s\n", 150 after_bootmem ? "after bootmem" : ""); 151 } 152 153 pr_debug("spp_getpage %p\n", ptr); 154 155 return ptr; 156 } 157 158 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr) 159 { 160 if (pgd_none(*pgd)) { 161 pud_t *pud = (pud_t *)spp_getpage(); 162 pgd_populate(&init_mm, pgd, pud); 163 if (pud != pud_offset(pgd, 0)) 164 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n", 165 pud, pud_offset(pgd, 0)); 166 } 167 return pud_offset(pgd, vaddr); 168 } 169 170 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr) 171 { 172 if (pud_none(*pud)) { 173 pmd_t *pmd = (pmd_t *) spp_getpage(); 174 pud_populate(&init_mm, pud, pmd); 175 if (pmd != pmd_offset(pud, 0)) 176 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n", 177 pmd, pmd_offset(pud, 0)); 178 } 179 return pmd_offset(pud, vaddr); 180 } 181 182 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr) 183 { 184 if (pmd_none(*pmd)) { 185 pte_t *pte = (pte_t *) spp_getpage(); 186 pmd_populate_kernel(&init_mm, pmd, pte); 187 if (pte != pte_offset_kernel(pmd, 0)) 188 printk(KERN_ERR "PAGETABLE BUG #02!\n"); 189 } 190 return pte_offset_kernel(pmd, vaddr); 191 } 192 193 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte) 194 { 195 pud_t *pud; 196 pmd_t *pmd; 197 pte_t *pte; 198 199 pud = pud_page + pud_index(vaddr); 200 pmd = fill_pmd(pud, vaddr); 201 pte = fill_pte(pmd, vaddr); 202 203 set_pte(pte, new_pte); 204 205 /* 206 * It's enough to flush this one mapping. 207 * (PGE mappings get flushed as well) 208 */ 209 __flush_tlb_one(vaddr); 210 } 211 212 void set_pte_vaddr(unsigned long vaddr, pte_t pteval) 213 { 214 pgd_t *pgd; 215 pud_t *pud_page; 216 217 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval)); 218 219 pgd = pgd_offset_k(vaddr); 220 if (pgd_none(*pgd)) { 221 printk(KERN_ERR 222 "PGD FIXMAP MISSING, it should be setup in head.S!\n"); 223 return; 224 } 225 pud_page = (pud_t*)pgd_page_vaddr(*pgd); 226 set_pte_vaddr_pud(pud_page, vaddr, pteval); 227 } 228 229 pmd_t * __init populate_extra_pmd(unsigned long vaddr) 230 { 231 pgd_t *pgd; 232 pud_t *pud; 233 234 pgd = pgd_offset_k(vaddr); 235 pud = fill_pud(pgd, vaddr); 236 return fill_pmd(pud, vaddr); 237 } 238 239 pte_t * __init populate_extra_pte(unsigned long vaddr) 240 { 241 pmd_t *pmd; 242 243 pmd = populate_extra_pmd(vaddr); 244 return fill_pte(pmd, vaddr); 245 } 246 247 /* 248 * Create large page table mappings for a range of physical addresses. 249 */ 250 static void __init __init_extra_mapping(unsigned long phys, unsigned long size, 251 pgprot_t prot) 252 { 253 pgd_t *pgd; 254 pud_t *pud; 255 pmd_t *pmd; 256 257 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK)); 258 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) { 259 pgd = pgd_offset_k((unsigned long)__va(phys)); 260 if (pgd_none(*pgd)) { 261 pud = (pud_t *) spp_getpage(); 262 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE | 263 _PAGE_USER)); 264 } 265 pud = pud_offset(pgd, (unsigned long)__va(phys)); 266 if (pud_none(*pud)) { 267 pmd = (pmd_t *) spp_getpage(); 268 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | 269 _PAGE_USER)); 270 } 271 pmd = pmd_offset(pud, phys); 272 BUG_ON(!pmd_none(*pmd)); 273 set_pmd(pmd, __pmd(phys | pgprot_val(prot))); 274 } 275 } 276 277 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size) 278 { 279 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE); 280 } 281 282 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size) 283 { 284 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE); 285 } 286 287 /* 288 * The head.S code sets up the kernel high mapping: 289 * 290 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text) 291 * 292 * phys_addr holds the negative offset to the kernel, which is added 293 * to the compile time generated pmds. This results in invalid pmds up 294 * to the point where we hit the physaddr 0 mapping. 295 * 296 * We limit the mappings to the region from _text to _end. _end is 297 * rounded up to the 2MB boundary. This catches the invalid pmds as 298 * well, as they are located before _text: 299 */ 300 void __init cleanup_highmap(void) 301 { 302 unsigned long vaddr = __START_KERNEL_map; 303 unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1; 304 pmd_t *pmd = level2_kernel_pgt; 305 pmd_t *last_pmd = pmd + PTRS_PER_PMD; 306 307 for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) { 308 if (pmd_none(*pmd)) 309 continue; 310 if (vaddr < (unsigned long) _text || vaddr > end) 311 set_pmd(pmd, __pmd(0)); 312 } 313 } 314 315 static __ref void *alloc_low_page(unsigned long *phys) 316 { 317 unsigned long pfn = e820_table_end++; 318 void *adr; 319 320 if (after_bootmem) { 321 adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 322 *phys = __pa(adr); 323 324 return adr; 325 } 326 327 if (pfn >= e820_table_top) 328 panic("alloc_low_page: ran out of memory"); 329 330 adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE); 331 clear_page(adr); 332 *phys = pfn * PAGE_SIZE; 333 return adr; 334 } 335 336 static __ref void unmap_low_page(void *adr) 337 { 338 if (after_bootmem) 339 return; 340 341 early_iounmap(adr, PAGE_SIZE); 342 } 343 344 static unsigned long __meminit 345 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, 346 pgprot_t prot) 347 { 348 unsigned pages = 0; 349 unsigned long last_map_addr = end; 350 int i; 351 352 pte_t *pte = pte_page + pte_index(addr); 353 354 for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { 355 356 if (addr >= end) { 357 if (!after_bootmem) { 358 for(; i < PTRS_PER_PTE; i++, pte++) 359 set_pte(pte, __pte(0)); 360 } 361 break; 362 } 363 364 /* 365 * We will re-use the existing mapping. 366 * Xen for example has some special requirements, like mapping 367 * pagetable pages as RO. So assume someone who pre-setup 368 * these mappings are more intelligent. 369 */ 370 if (pte_val(*pte)) { 371 pages++; 372 continue; 373 } 374 375 if (0) 376 printk(" pte=%p addr=%lx pte=%016lx\n", 377 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); 378 pages++; 379 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot)); 380 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; 381 } 382 383 update_page_count(PG_LEVEL_4K, pages); 384 385 return last_map_addr; 386 } 387 388 static unsigned long __meminit 389 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end, 390 pgprot_t prot) 391 { 392 pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd); 393 394 return phys_pte_init(pte, address, end, prot); 395 } 396 397 static unsigned long __meminit 398 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 399 unsigned long page_size_mask, pgprot_t prot) 400 { 401 unsigned long pages = 0; 402 unsigned long last_map_addr = end; 403 404 int i = pmd_index(address); 405 406 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) { 407 unsigned long pte_phys; 408 pmd_t *pmd = pmd_page + pmd_index(address); 409 pte_t *pte; 410 pgprot_t new_prot = prot; 411 412 if (address >= end) { 413 if (!after_bootmem) { 414 for (; i < PTRS_PER_PMD; i++, pmd++) 415 set_pmd(pmd, __pmd(0)); 416 } 417 break; 418 } 419 420 if (pmd_val(*pmd)) { 421 if (!pmd_large(*pmd)) { 422 spin_lock(&init_mm.page_table_lock); 423 last_map_addr = phys_pte_update(pmd, address, 424 end, prot); 425 spin_unlock(&init_mm.page_table_lock); 426 continue; 427 } 428 /* 429 * If we are ok with PG_LEVEL_2M mapping, then we will 430 * use the existing mapping, 431 * 432 * Otherwise, we will split the large page mapping but 433 * use the same existing protection bits except for 434 * large page, so that we don't violate Intel's TLB 435 * Application note (317080) which says, while changing 436 * the page sizes, new and old translations should 437 * not differ with respect to page frame and 438 * attributes. 439 */ 440 if (page_size_mask & (1 << PG_LEVEL_2M)) { 441 pages++; 442 continue; 443 } 444 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); 445 } 446 447 if (page_size_mask & (1<<PG_LEVEL_2M)) { 448 pages++; 449 spin_lock(&init_mm.page_table_lock); 450 set_pte((pte_t *)pmd, 451 pfn_pte(address >> PAGE_SHIFT, 452 __pgprot(pgprot_val(prot) | _PAGE_PSE))); 453 spin_unlock(&init_mm.page_table_lock); 454 last_map_addr = (address & PMD_MASK) + PMD_SIZE; 455 continue; 456 } 457 458 pte = alloc_low_page(&pte_phys); 459 last_map_addr = phys_pte_init(pte, address, end, new_prot); 460 unmap_low_page(pte); 461 462 spin_lock(&init_mm.page_table_lock); 463 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); 464 spin_unlock(&init_mm.page_table_lock); 465 } 466 update_page_count(PG_LEVEL_2M, pages); 467 return last_map_addr; 468 } 469 470 static unsigned long __meminit 471 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end, 472 unsigned long page_size_mask, pgprot_t prot) 473 { 474 pmd_t *pmd = pmd_offset(pud, 0); 475 unsigned long last_map_addr; 476 477 last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot); 478 __flush_tlb_all(); 479 return last_map_addr; 480 } 481 482 static unsigned long __meminit 483 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 484 unsigned long page_size_mask) 485 { 486 unsigned long pages = 0; 487 unsigned long last_map_addr = end; 488 int i = pud_index(addr); 489 490 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) { 491 unsigned long pmd_phys; 492 pud_t *pud = pud_page + pud_index(addr); 493 pmd_t *pmd; 494 pgprot_t prot = PAGE_KERNEL; 495 496 if (addr >= end) 497 break; 498 499 if (!after_bootmem && 500 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) { 501 set_pud(pud, __pud(0)); 502 continue; 503 } 504 505 if (pud_val(*pud)) { 506 if (!pud_large(*pud)) { 507 last_map_addr = phys_pmd_update(pud, addr, end, 508 page_size_mask, prot); 509 continue; 510 } 511 /* 512 * If we are ok with PG_LEVEL_1G mapping, then we will 513 * use the existing mapping. 514 * 515 * Otherwise, we will split the gbpage mapping but use 516 * the same existing protection bits except for large 517 * page, so that we don't violate Intel's TLB 518 * Application note (317080) which says, while changing 519 * the page sizes, new and old translations should 520 * not differ with respect to page frame and 521 * attributes. 522 */ 523 if (page_size_mask & (1 << PG_LEVEL_1G)) { 524 pages++; 525 continue; 526 } 527 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); 528 } 529 530 if (page_size_mask & (1<<PG_LEVEL_1G)) { 531 pages++; 532 spin_lock(&init_mm.page_table_lock); 533 set_pte((pte_t *)pud, 534 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); 535 spin_unlock(&init_mm.page_table_lock); 536 last_map_addr = (addr & PUD_MASK) + PUD_SIZE; 537 continue; 538 } 539 540 pmd = alloc_low_page(&pmd_phys); 541 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, 542 prot); 543 unmap_low_page(pmd); 544 545 spin_lock(&init_mm.page_table_lock); 546 pud_populate(&init_mm, pud, __va(pmd_phys)); 547 spin_unlock(&init_mm.page_table_lock); 548 } 549 __flush_tlb_all(); 550 551 update_page_count(PG_LEVEL_1G, pages); 552 553 return last_map_addr; 554 } 555 556 static unsigned long __meminit 557 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end, 558 unsigned long page_size_mask) 559 { 560 pud_t *pud; 561 562 pud = (pud_t *)pgd_page_vaddr(*pgd); 563 564 return phys_pud_init(pud, addr, end, page_size_mask); 565 } 566 567 unsigned long __meminit 568 kernel_physical_mapping_init(unsigned long start, 569 unsigned long end, 570 unsigned long page_size_mask) 571 { 572 bool pgd_changed = false; 573 unsigned long next, last_map_addr = end; 574 unsigned long addr; 575 576 start = (unsigned long)__va(start); 577 end = (unsigned long)__va(end); 578 addr = start; 579 580 for (; start < end; start = next) { 581 pgd_t *pgd = pgd_offset_k(start); 582 unsigned long pud_phys; 583 pud_t *pud; 584 585 next = (start + PGDIR_SIZE) & PGDIR_MASK; 586 if (next > end) 587 next = end; 588 589 if (pgd_val(*pgd)) { 590 last_map_addr = phys_pud_update(pgd, __pa(start), 591 __pa(end), page_size_mask); 592 continue; 593 } 594 595 pud = alloc_low_page(&pud_phys); 596 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next), 597 page_size_mask); 598 unmap_low_page(pud); 599 600 spin_lock(&init_mm.page_table_lock); 601 pgd_populate(&init_mm, pgd, __va(pud_phys)); 602 spin_unlock(&init_mm.page_table_lock); 603 pgd_changed = true; 604 } 605 606 if (pgd_changed) 607 sync_global_pgds(addr, end); 608 609 __flush_tlb_all(); 610 611 return last_map_addr; 612 } 613 614 #ifndef CONFIG_NUMA 615 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn, 616 int acpi, int k8) 617 { 618 memblock_x86_register_active_regions(0, start_pfn, end_pfn); 619 } 620 #endif 621 622 void __init paging_init(void) 623 { 624 unsigned long max_zone_pfns[MAX_NR_ZONES]; 625 626 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 627 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN; 628 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN; 629 max_zone_pfns[ZONE_NORMAL] = max_pfn; 630 631 sparse_memory_present_with_active_regions(MAX_NUMNODES); 632 sparse_init(); 633 634 /* 635 * clear the default setting with node 0 636 * note: don't use nodes_clear here, that is really clearing when 637 * numa support is not compiled in, and later node_set_state 638 * will not set it back. 639 */ 640 node_clear_state(0, N_NORMAL_MEMORY); 641 642 free_area_init_nodes(max_zone_pfns); 643 } 644 645 /* 646 * Memory hotplug specific functions 647 */ 648 #ifdef CONFIG_MEMORY_HOTPLUG 649 /* 650 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need 651 * updating. 652 */ 653 static void update_end_of_memory_vars(u64 start, u64 size) 654 { 655 unsigned long end_pfn = PFN_UP(start + size); 656 657 if (end_pfn > max_pfn) { 658 max_pfn = end_pfn; 659 max_low_pfn = end_pfn; 660 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; 661 } 662 } 663 664 /* 665 * Memory is added always to NORMAL zone. This means you will never get 666 * additional DMA/DMA32 memory. 667 */ 668 int arch_add_memory(int nid, u64 start, u64 size) 669 { 670 struct pglist_data *pgdat = NODE_DATA(nid); 671 struct zone *zone = pgdat->node_zones + ZONE_NORMAL; 672 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT; 673 unsigned long nr_pages = size >> PAGE_SHIFT; 674 int ret; 675 676 last_mapped_pfn = init_memory_mapping(start, start + size); 677 if (last_mapped_pfn > max_pfn_mapped) 678 max_pfn_mapped = last_mapped_pfn; 679 680 ret = __add_pages(nid, zone, start_pfn, nr_pages); 681 WARN_ON_ONCE(ret); 682 683 /* update max_pfn, max_low_pfn and high_memory */ 684 update_end_of_memory_vars(start, size); 685 686 return ret; 687 } 688 EXPORT_SYMBOL_GPL(arch_add_memory); 689 690 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA) 691 int memory_add_physaddr_to_nid(u64 start) 692 { 693 return 0; 694 } 695 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); 696 #endif 697 698 #endif /* CONFIG_MEMORY_HOTPLUG */ 699 700 static struct kcore_list kcore_vsyscall; 701 702 void __init mem_init(void) 703 { 704 long codesize, reservedpages, datasize, initsize; 705 unsigned long absent_pages; 706 707 pci_iommu_alloc(); 708 709 /* clear_bss() already clear the empty_zero_page */ 710 711 reservedpages = 0; 712 713 /* this will put all low memory onto the freelists */ 714 #ifdef CONFIG_NUMA 715 totalram_pages = numa_free_all_bootmem(); 716 #else 717 totalram_pages = free_all_bootmem(); 718 #endif 719 720 absent_pages = absent_pages_in_range(0, max_pfn); 721 reservedpages = max_pfn - totalram_pages - absent_pages; 722 after_bootmem = 1; 723 724 codesize = (unsigned long) &_etext - (unsigned long) &_text; 725 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 726 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 727 728 /* Register memory areas for /proc/kcore */ 729 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, 730 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER); 731 732 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, " 733 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n", 734 nr_free_pages() << (PAGE_SHIFT-10), 735 max_pfn << (PAGE_SHIFT-10), 736 codesize >> 10, 737 absent_pages << (PAGE_SHIFT-10), 738 reservedpages << (PAGE_SHIFT-10), 739 datasize >> 10, 740 initsize >> 10); 741 } 742 743 #ifdef CONFIG_DEBUG_RODATA 744 const int rodata_test_data = 0xC3; 745 EXPORT_SYMBOL_GPL(rodata_test_data); 746 747 int kernel_set_to_readonly; 748 749 void set_kernel_text_rw(void) 750 { 751 unsigned long start = PFN_ALIGN(_text); 752 unsigned long end = PFN_ALIGN(__stop___ex_table); 753 754 if (!kernel_set_to_readonly) 755 return; 756 757 pr_debug("Set kernel text: %lx - %lx for read write\n", 758 start, end); 759 760 /* 761 * Make the kernel identity mapping for text RW. Kernel text 762 * mapping will always be RO. Refer to the comment in 763 * static_protections() in pageattr.c 764 */ 765 set_memory_rw(start, (end - start) >> PAGE_SHIFT); 766 } 767 768 void set_kernel_text_ro(void) 769 { 770 unsigned long start = PFN_ALIGN(_text); 771 unsigned long end = PFN_ALIGN(__stop___ex_table); 772 773 if (!kernel_set_to_readonly) 774 return; 775 776 pr_debug("Set kernel text: %lx - %lx for read only\n", 777 start, end); 778 779 /* 780 * Set the kernel identity mapping for text RO. 781 */ 782 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 783 } 784 785 void mark_rodata_ro(void) 786 { 787 unsigned long start = PFN_ALIGN(_text); 788 unsigned long rodata_start = 789 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; 790 unsigned long end = (unsigned long) &__end_rodata_hpage_align; 791 unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table); 792 unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata); 793 unsigned long data_start = (unsigned long) &_sdata; 794 795 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 796 (end - start) >> 10); 797 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 798 799 kernel_set_to_readonly = 1; 800 801 /* 802 * The rodata section (but not the kernel text!) should also be 803 * not-executable. 804 */ 805 set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); 806 807 rodata_test(); 808 809 #ifdef CONFIG_CPA_DEBUG 810 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end); 811 set_memory_rw(start, (end-start) >> PAGE_SHIFT); 812 813 printk(KERN_INFO "Testing CPA: again\n"); 814 set_memory_ro(start, (end-start) >> PAGE_SHIFT); 815 #endif 816 817 free_init_pages("unused kernel memory", 818 (unsigned long) page_address(virt_to_page(text_end)), 819 (unsigned long) 820 page_address(virt_to_page(rodata_start))); 821 free_init_pages("unused kernel memory", 822 (unsigned long) page_address(virt_to_page(rodata_end)), 823 (unsigned long) page_address(virt_to_page(data_start))); 824 } 825 826 #endif 827 828 int kern_addr_valid(unsigned long addr) 829 { 830 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; 831 pgd_t *pgd; 832 pud_t *pud; 833 pmd_t *pmd; 834 pte_t *pte; 835 836 if (above != 0 && above != -1UL) 837 return 0; 838 839 pgd = pgd_offset_k(addr); 840 if (pgd_none(*pgd)) 841 return 0; 842 843 pud = pud_offset(pgd, addr); 844 if (pud_none(*pud)) 845 return 0; 846 847 pmd = pmd_offset(pud, addr); 848 if (pmd_none(*pmd)) 849 return 0; 850 851 if (pmd_large(*pmd)) 852 return pfn_valid(pmd_pfn(*pmd)); 853 854 pte = pte_offset_kernel(pmd, addr); 855 if (pte_none(*pte)) 856 return 0; 857 858 return pfn_valid(pte_pfn(*pte)); 859 } 860 861 /* 862 * A pseudo VMA to allow ptrace access for the vsyscall page. This only 863 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does 864 * not need special handling anymore: 865 */ 866 static struct vm_area_struct gate_vma = { 867 .vm_start = VSYSCALL_START, 868 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE), 869 .vm_page_prot = PAGE_READONLY_EXEC, 870 .vm_flags = VM_READ | VM_EXEC 871 }; 872 873 struct vm_area_struct *get_gate_vma(struct task_struct *tsk) 874 { 875 #ifdef CONFIG_IA32_EMULATION 876 if (test_tsk_thread_flag(tsk, TIF_IA32)) 877 return NULL; 878 #endif 879 return &gate_vma; 880 } 881 882 int in_gate_area(struct task_struct *task, unsigned long addr) 883 { 884 struct vm_area_struct *vma = get_gate_vma(task); 885 886 if (!vma) 887 return 0; 888 889 return (addr >= vma->vm_start) && (addr < vma->vm_end); 890 } 891 892 /* 893 * Use this when you have no reliable task/vma, typically from interrupt 894 * context. It is less reliable than using the task's vma and may give 895 * false positives: 896 */ 897 int in_gate_area_no_task(unsigned long addr) 898 { 899 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END); 900 } 901 902 const char *arch_vma_name(struct vm_area_struct *vma) 903 { 904 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) 905 return "[vdso]"; 906 if (vma == &gate_vma) 907 return "[vsyscall]"; 908 return NULL; 909 } 910 911 #ifdef CONFIG_SPARSEMEM_VMEMMAP 912 /* 913 * Initialise the sparsemem vmemmap using huge-pages at the PMD level. 914 */ 915 static long __meminitdata addr_start, addr_end; 916 static void __meminitdata *p_start, *p_end; 917 static int __meminitdata node_start; 918 919 int __meminit 920 vmemmap_populate(struct page *start_page, unsigned long size, int node) 921 { 922 unsigned long addr = (unsigned long)start_page; 923 unsigned long end = (unsigned long)(start_page + size); 924 unsigned long next; 925 pgd_t *pgd; 926 pud_t *pud; 927 pmd_t *pmd; 928 929 for (; addr < end; addr = next) { 930 void *p = NULL; 931 932 pgd = vmemmap_pgd_populate(addr, node); 933 if (!pgd) 934 return -ENOMEM; 935 936 pud = vmemmap_pud_populate(pgd, addr, node); 937 if (!pud) 938 return -ENOMEM; 939 940 if (!cpu_has_pse) { 941 next = (addr + PAGE_SIZE) & PAGE_MASK; 942 pmd = vmemmap_pmd_populate(pud, addr, node); 943 944 if (!pmd) 945 return -ENOMEM; 946 947 p = vmemmap_pte_populate(pmd, addr, node); 948 949 if (!p) 950 return -ENOMEM; 951 952 addr_end = addr + PAGE_SIZE; 953 p_end = p + PAGE_SIZE; 954 } else { 955 next = pmd_addr_end(addr, end); 956 957 pmd = pmd_offset(pud, addr); 958 if (pmd_none(*pmd)) { 959 pte_t entry; 960 961 p = vmemmap_alloc_block_buf(PMD_SIZE, node); 962 if (!p) 963 return -ENOMEM; 964 965 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, 966 PAGE_KERNEL_LARGE); 967 set_pmd(pmd, __pmd(pte_val(entry))); 968 969 /* check to see if we have contiguous blocks */ 970 if (p_end != p || node_start != node) { 971 if (p_start) 972 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 973 addr_start, addr_end-1, p_start, p_end-1, node_start); 974 addr_start = addr; 975 node_start = node; 976 p_start = p; 977 } 978 979 addr_end = addr + PMD_SIZE; 980 p_end = p + PMD_SIZE; 981 } else 982 vmemmap_verify((pte_t *)pmd, node, addr, next); 983 } 984 985 } 986 sync_global_pgds((unsigned long)start_page, end); 987 return 0; 988 } 989 990 void __meminit vmemmap_populate_print_last(void) 991 { 992 if (p_start) { 993 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 994 addr_start, addr_end-1, p_start, p_end-1, node_start); 995 p_start = NULL; 996 p_end = NULL; 997 node_start = 0; 998 } 999 } 1000 #endif 1001