1 /* 2 * linux/arch/x86_64/mm/init.c 3 * 4 * Copyright (C) 1995 Linus Torvalds 5 * Copyright (C) 2000 Pavel Machek <pavel@suse.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/proc_fs.h> 25 #include <linux/pci.h> 26 #include <linux/pfn.h> 27 #include <linux/poison.h> 28 #include <linux/dma-mapping.h> 29 #include <linux/module.h> 30 #include <linux/memory_hotplug.h> 31 #include <linux/nmi.h> 32 33 #include <asm/processor.h> 34 #include <asm/bios_ebda.h> 35 #include <asm/system.h> 36 #include <asm/uaccess.h> 37 #include <asm/pgtable.h> 38 #include <asm/pgalloc.h> 39 #include <asm/dma.h> 40 #include <asm/fixmap.h> 41 #include <asm/e820.h> 42 #include <asm/apic.h> 43 #include <asm/tlb.h> 44 #include <asm/mmu_context.h> 45 #include <asm/proto.h> 46 #include <asm/smp.h> 47 #include <asm/sections.h> 48 #include <asm/kdebug.h> 49 #include <asm/numa.h> 50 #include <asm/cacheflush.h> 51 #include <asm/init.h> 52 53 static unsigned long dma_reserve __initdata; 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 * NOTE: This function is marked __ref because it calls __init function 100 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. 101 */ 102 static __ref void *spp_getpage(void) 103 { 104 void *ptr; 105 106 if (after_bootmem) 107 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 108 else 109 ptr = alloc_bootmem_pages(PAGE_SIZE); 110 111 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) { 112 panic("set_pte_phys: cannot allocate page data %s\n", 113 after_bootmem ? "after bootmem" : ""); 114 } 115 116 pr_debug("spp_getpage %p\n", ptr); 117 118 return ptr; 119 } 120 121 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr) 122 { 123 if (pgd_none(*pgd)) { 124 pud_t *pud = (pud_t *)spp_getpage(); 125 pgd_populate(&init_mm, pgd, pud); 126 if (pud != pud_offset(pgd, 0)) 127 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n", 128 pud, pud_offset(pgd, 0)); 129 } 130 return pud_offset(pgd, vaddr); 131 } 132 133 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr) 134 { 135 if (pud_none(*pud)) { 136 pmd_t *pmd = (pmd_t *) spp_getpage(); 137 pud_populate(&init_mm, pud, pmd); 138 if (pmd != pmd_offset(pud, 0)) 139 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n", 140 pmd, pmd_offset(pud, 0)); 141 } 142 return pmd_offset(pud, vaddr); 143 } 144 145 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr) 146 { 147 if (pmd_none(*pmd)) { 148 pte_t *pte = (pte_t *) spp_getpage(); 149 pmd_populate_kernel(&init_mm, pmd, pte); 150 if (pte != pte_offset_kernel(pmd, 0)) 151 printk(KERN_ERR "PAGETABLE BUG #02!\n"); 152 } 153 return pte_offset_kernel(pmd, vaddr); 154 } 155 156 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte) 157 { 158 pud_t *pud; 159 pmd_t *pmd; 160 pte_t *pte; 161 162 pud = pud_page + pud_index(vaddr); 163 pmd = fill_pmd(pud, vaddr); 164 pte = fill_pte(pmd, vaddr); 165 166 set_pte(pte, new_pte); 167 168 /* 169 * It's enough to flush this one mapping. 170 * (PGE mappings get flushed as well) 171 */ 172 __flush_tlb_one(vaddr); 173 } 174 175 void set_pte_vaddr(unsigned long vaddr, pte_t pteval) 176 { 177 pgd_t *pgd; 178 pud_t *pud_page; 179 180 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval)); 181 182 pgd = pgd_offset_k(vaddr); 183 if (pgd_none(*pgd)) { 184 printk(KERN_ERR 185 "PGD FIXMAP MISSING, it should be setup in head.S!\n"); 186 return; 187 } 188 pud_page = (pud_t*)pgd_page_vaddr(*pgd); 189 set_pte_vaddr_pud(pud_page, vaddr, pteval); 190 } 191 192 pmd_t * __init populate_extra_pmd(unsigned long vaddr) 193 { 194 pgd_t *pgd; 195 pud_t *pud; 196 197 pgd = pgd_offset_k(vaddr); 198 pud = fill_pud(pgd, vaddr); 199 return fill_pmd(pud, vaddr); 200 } 201 202 pte_t * __init populate_extra_pte(unsigned long vaddr) 203 { 204 pmd_t *pmd; 205 206 pmd = populate_extra_pmd(vaddr); 207 return fill_pte(pmd, vaddr); 208 } 209 210 /* 211 * Create large page table mappings for a range of physical addresses. 212 */ 213 static void __init __init_extra_mapping(unsigned long phys, unsigned long size, 214 pgprot_t prot) 215 { 216 pgd_t *pgd; 217 pud_t *pud; 218 pmd_t *pmd; 219 220 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK)); 221 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) { 222 pgd = pgd_offset_k((unsigned long)__va(phys)); 223 if (pgd_none(*pgd)) { 224 pud = (pud_t *) spp_getpage(); 225 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE | 226 _PAGE_USER)); 227 } 228 pud = pud_offset(pgd, (unsigned long)__va(phys)); 229 if (pud_none(*pud)) { 230 pmd = (pmd_t *) spp_getpage(); 231 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | 232 _PAGE_USER)); 233 } 234 pmd = pmd_offset(pud, phys); 235 BUG_ON(!pmd_none(*pmd)); 236 set_pmd(pmd, __pmd(phys | pgprot_val(prot))); 237 } 238 } 239 240 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size) 241 { 242 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE); 243 } 244 245 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size) 246 { 247 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE); 248 } 249 250 /* 251 * The head.S code sets up the kernel high mapping: 252 * 253 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text) 254 * 255 * phys_addr holds the negative offset to the kernel, which is added 256 * to the compile time generated pmds. This results in invalid pmds up 257 * to the point where we hit the physaddr 0 mapping. 258 * 259 * We limit the mappings to the region from _text to _end. _end is 260 * rounded up to the 2MB boundary. This catches the invalid pmds as 261 * well, as they are located before _text: 262 */ 263 void __init cleanup_highmap(void) 264 { 265 unsigned long vaddr = __START_KERNEL_map; 266 unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1; 267 pmd_t *pmd = level2_kernel_pgt; 268 pmd_t *last_pmd = pmd + PTRS_PER_PMD; 269 270 for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) { 271 if (pmd_none(*pmd)) 272 continue; 273 if (vaddr < (unsigned long) _text || vaddr > end) 274 set_pmd(pmd, __pmd(0)); 275 } 276 } 277 278 static __ref void *alloc_low_page(unsigned long *phys) 279 { 280 unsigned long pfn = e820_table_end++; 281 void *adr; 282 283 if (after_bootmem) { 284 adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 285 *phys = __pa(adr); 286 287 return adr; 288 } 289 290 if (pfn >= e820_table_top) 291 panic("alloc_low_page: ran out of memory"); 292 293 adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE); 294 memset(adr, 0, PAGE_SIZE); 295 *phys = pfn * PAGE_SIZE; 296 return adr; 297 } 298 299 static __ref void unmap_low_page(void *adr) 300 { 301 if (after_bootmem) 302 return; 303 304 early_iounmap(adr, PAGE_SIZE); 305 } 306 307 static unsigned long __meminit 308 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, 309 pgprot_t prot) 310 { 311 unsigned pages = 0; 312 unsigned long last_map_addr = end; 313 int i; 314 315 pte_t *pte = pte_page + pte_index(addr); 316 317 for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { 318 319 if (addr >= end) { 320 if (!after_bootmem) { 321 for(; i < PTRS_PER_PTE; i++, pte++) 322 set_pte(pte, __pte(0)); 323 } 324 break; 325 } 326 327 /* 328 * We will re-use the existing mapping. 329 * Xen for example has some special requirements, like mapping 330 * pagetable pages as RO. So assume someone who pre-setup 331 * these mappings are more intelligent. 332 */ 333 if (pte_val(*pte)) { 334 pages++; 335 continue; 336 } 337 338 if (0) 339 printk(" pte=%p addr=%lx pte=%016lx\n", 340 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); 341 pages++; 342 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot)); 343 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; 344 } 345 346 update_page_count(PG_LEVEL_4K, pages); 347 348 return last_map_addr; 349 } 350 351 static unsigned long __meminit 352 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end, 353 pgprot_t prot) 354 { 355 pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd); 356 357 return phys_pte_init(pte, address, end, prot); 358 } 359 360 static unsigned long __meminit 361 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 362 unsigned long page_size_mask, pgprot_t prot) 363 { 364 unsigned long pages = 0; 365 unsigned long last_map_addr = end; 366 367 int i = pmd_index(address); 368 369 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) { 370 unsigned long pte_phys; 371 pmd_t *pmd = pmd_page + pmd_index(address); 372 pte_t *pte; 373 pgprot_t new_prot = prot; 374 375 if (address >= end) { 376 if (!after_bootmem) { 377 for (; i < PTRS_PER_PMD; i++, pmd++) 378 set_pmd(pmd, __pmd(0)); 379 } 380 break; 381 } 382 383 if (pmd_val(*pmd)) { 384 if (!pmd_large(*pmd)) { 385 spin_lock(&init_mm.page_table_lock); 386 last_map_addr = phys_pte_update(pmd, address, 387 end, prot); 388 spin_unlock(&init_mm.page_table_lock); 389 continue; 390 } 391 /* 392 * If we are ok with PG_LEVEL_2M mapping, then we will 393 * use the existing mapping, 394 * 395 * Otherwise, we will split the large page mapping but 396 * use the same existing protection bits except for 397 * large page, so that we don't violate Intel's TLB 398 * Application note (317080) which says, while changing 399 * the page sizes, new and old translations should 400 * not differ with respect to page frame and 401 * attributes. 402 */ 403 if (page_size_mask & (1 << PG_LEVEL_2M)) { 404 pages++; 405 continue; 406 } 407 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); 408 } 409 410 if (page_size_mask & (1<<PG_LEVEL_2M)) { 411 pages++; 412 spin_lock(&init_mm.page_table_lock); 413 set_pte((pte_t *)pmd, 414 pfn_pte(address >> PAGE_SHIFT, 415 __pgprot(pgprot_val(prot) | _PAGE_PSE))); 416 spin_unlock(&init_mm.page_table_lock); 417 last_map_addr = (address & PMD_MASK) + PMD_SIZE; 418 continue; 419 } 420 421 pte = alloc_low_page(&pte_phys); 422 last_map_addr = phys_pte_init(pte, address, end, new_prot); 423 unmap_low_page(pte); 424 425 spin_lock(&init_mm.page_table_lock); 426 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); 427 spin_unlock(&init_mm.page_table_lock); 428 } 429 update_page_count(PG_LEVEL_2M, pages); 430 return last_map_addr; 431 } 432 433 static unsigned long __meminit 434 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end, 435 unsigned long page_size_mask, pgprot_t prot) 436 { 437 pmd_t *pmd = pmd_offset(pud, 0); 438 unsigned long last_map_addr; 439 440 last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot); 441 __flush_tlb_all(); 442 return last_map_addr; 443 } 444 445 static unsigned long __meminit 446 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 447 unsigned long page_size_mask) 448 { 449 unsigned long pages = 0; 450 unsigned long last_map_addr = end; 451 int i = pud_index(addr); 452 453 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) { 454 unsigned long pmd_phys; 455 pud_t *pud = pud_page + pud_index(addr); 456 pmd_t *pmd; 457 pgprot_t prot = PAGE_KERNEL; 458 459 if (addr >= end) 460 break; 461 462 if (!after_bootmem && 463 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) { 464 set_pud(pud, __pud(0)); 465 continue; 466 } 467 468 if (pud_val(*pud)) { 469 if (!pud_large(*pud)) { 470 last_map_addr = phys_pmd_update(pud, addr, end, 471 page_size_mask, prot); 472 continue; 473 } 474 /* 475 * If we are ok with PG_LEVEL_1G mapping, then we will 476 * use the existing mapping. 477 * 478 * Otherwise, we will split the gbpage mapping but use 479 * the same existing protection bits except for large 480 * page, so that we don't violate Intel's TLB 481 * Application note (317080) which says, while changing 482 * the page sizes, new and old translations should 483 * not differ with respect to page frame and 484 * attributes. 485 */ 486 if (page_size_mask & (1 << PG_LEVEL_1G)) { 487 pages++; 488 continue; 489 } 490 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); 491 } 492 493 if (page_size_mask & (1<<PG_LEVEL_1G)) { 494 pages++; 495 spin_lock(&init_mm.page_table_lock); 496 set_pte((pte_t *)pud, 497 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); 498 spin_unlock(&init_mm.page_table_lock); 499 last_map_addr = (addr & PUD_MASK) + PUD_SIZE; 500 continue; 501 } 502 503 pmd = alloc_low_page(&pmd_phys); 504 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, 505 prot); 506 unmap_low_page(pmd); 507 508 spin_lock(&init_mm.page_table_lock); 509 pud_populate(&init_mm, pud, __va(pmd_phys)); 510 spin_unlock(&init_mm.page_table_lock); 511 } 512 __flush_tlb_all(); 513 514 update_page_count(PG_LEVEL_1G, pages); 515 516 return last_map_addr; 517 } 518 519 static unsigned long __meminit 520 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end, 521 unsigned long page_size_mask) 522 { 523 pud_t *pud; 524 525 pud = (pud_t *)pgd_page_vaddr(*pgd); 526 527 return phys_pud_init(pud, addr, end, page_size_mask); 528 } 529 530 unsigned long __meminit 531 kernel_physical_mapping_init(unsigned long start, 532 unsigned long end, 533 unsigned long page_size_mask) 534 { 535 536 unsigned long next, last_map_addr = end; 537 538 start = (unsigned long)__va(start); 539 end = (unsigned long)__va(end); 540 541 for (; start < end; start = next) { 542 pgd_t *pgd = pgd_offset_k(start); 543 unsigned long pud_phys; 544 pud_t *pud; 545 546 next = (start + PGDIR_SIZE) & PGDIR_MASK; 547 if (next > end) 548 next = end; 549 550 if (pgd_val(*pgd)) { 551 last_map_addr = phys_pud_update(pgd, __pa(start), 552 __pa(end), page_size_mask); 553 continue; 554 } 555 556 pud = alloc_low_page(&pud_phys); 557 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next), 558 page_size_mask); 559 unmap_low_page(pud); 560 561 spin_lock(&init_mm.page_table_lock); 562 pgd_populate(&init_mm, pgd, __va(pud_phys)); 563 spin_unlock(&init_mm.page_table_lock); 564 } 565 __flush_tlb_all(); 566 567 return last_map_addr; 568 } 569 570 #ifndef CONFIG_NUMA 571 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn, 572 int acpi, int k8) 573 { 574 unsigned long bootmap_size, bootmap; 575 576 bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT; 577 bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size, 578 PAGE_SIZE); 579 if (bootmap == -1L) 580 panic("Cannot find bootmem map of size %ld\n", bootmap_size); 581 /* don't touch min_low_pfn */ 582 bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT, 583 0, end_pfn); 584 e820_register_active_regions(0, start_pfn, end_pfn); 585 free_bootmem_with_active_regions(0, end_pfn); 586 early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT); 587 reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT); 588 } 589 #endif 590 591 void __init paging_init(void) 592 { 593 unsigned long max_zone_pfns[MAX_NR_ZONES]; 594 595 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 596 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN; 597 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN; 598 max_zone_pfns[ZONE_NORMAL] = max_pfn; 599 600 sparse_memory_present_with_active_regions(MAX_NUMNODES); 601 sparse_init(); 602 603 /* 604 * clear the default setting with node 0 605 * note: don't use nodes_clear here, that is really clearing when 606 * numa support is not compiled in, and later node_set_state 607 * will not set it back. 608 */ 609 node_clear_state(0, N_NORMAL_MEMORY); 610 611 free_area_init_nodes(max_zone_pfns); 612 } 613 614 /* 615 * Memory hotplug specific functions 616 */ 617 #ifdef CONFIG_MEMORY_HOTPLUG 618 /* 619 * Memory is added always to NORMAL zone. This means you will never get 620 * additional DMA/DMA32 memory. 621 */ 622 int arch_add_memory(int nid, u64 start, u64 size) 623 { 624 struct pglist_data *pgdat = NODE_DATA(nid); 625 struct zone *zone = pgdat->node_zones + ZONE_NORMAL; 626 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT; 627 unsigned long nr_pages = size >> PAGE_SHIFT; 628 int ret; 629 630 last_mapped_pfn = init_memory_mapping(start, start + size); 631 if (last_mapped_pfn > max_pfn_mapped) 632 max_pfn_mapped = last_mapped_pfn; 633 634 ret = __add_pages(nid, zone, start_pfn, nr_pages); 635 WARN_ON_ONCE(ret); 636 637 return ret; 638 } 639 EXPORT_SYMBOL_GPL(arch_add_memory); 640 641 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA) 642 int memory_add_physaddr_to_nid(u64 start) 643 { 644 return 0; 645 } 646 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); 647 #endif 648 649 #endif /* CONFIG_MEMORY_HOTPLUG */ 650 651 static struct kcore_list kcore_vsyscall; 652 653 void __init mem_init(void) 654 { 655 long codesize, reservedpages, datasize, initsize; 656 unsigned long absent_pages; 657 658 pci_iommu_alloc(); 659 660 /* clear_bss() already clear the empty_zero_page */ 661 662 reservedpages = 0; 663 664 /* this will put all low memory onto the freelists */ 665 #ifdef CONFIG_NUMA 666 totalram_pages = numa_free_all_bootmem(); 667 #else 668 totalram_pages = free_all_bootmem(); 669 #endif 670 671 absent_pages = absent_pages_in_range(0, max_pfn); 672 reservedpages = max_pfn - totalram_pages - absent_pages; 673 after_bootmem = 1; 674 675 codesize = (unsigned long) &_etext - (unsigned long) &_text; 676 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 677 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 678 679 /* Register memory areas for /proc/kcore */ 680 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, 681 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER); 682 683 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, " 684 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n", 685 nr_free_pages() << (PAGE_SHIFT-10), 686 max_pfn << (PAGE_SHIFT-10), 687 codesize >> 10, 688 absent_pages << (PAGE_SHIFT-10), 689 reservedpages << (PAGE_SHIFT-10), 690 datasize >> 10, 691 initsize >> 10); 692 } 693 694 #ifdef CONFIG_DEBUG_RODATA 695 const int rodata_test_data = 0xC3; 696 EXPORT_SYMBOL_GPL(rodata_test_data); 697 698 int kernel_set_to_readonly; 699 700 void set_kernel_text_rw(void) 701 { 702 unsigned long start = PFN_ALIGN(_text); 703 unsigned long end = PFN_ALIGN(__stop___ex_table); 704 705 if (!kernel_set_to_readonly) 706 return; 707 708 pr_debug("Set kernel text: %lx - %lx for read write\n", 709 start, end); 710 711 /* 712 * Make the kernel identity mapping for text RW. Kernel text 713 * mapping will always be RO. Refer to the comment in 714 * static_protections() in pageattr.c 715 */ 716 set_memory_rw(start, (end - start) >> PAGE_SHIFT); 717 } 718 719 void set_kernel_text_ro(void) 720 { 721 unsigned long start = PFN_ALIGN(_text); 722 unsigned long end = PFN_ALIGN(__stop___ex_table); 723 724 if (!kernel_set_to_readonly) 725 return; 726 727 pr_debug("Set kernel text: %lx - %lx for read only\n", 728 start, end); 729 730 /* 731 * Set the kernel identity mapping for text RO. 732 */ 733 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 734 } 735 736 void mark_rodata_ro(void) 737 { 738 unsigned long start = PFN_ALIGN(_text); 739 unsigned long rodata_start = 740 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; 741 unsigned long end = (unsigned long) &__end_rodata_hpage_align; 742 unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table); 743 unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata); 744 unsigned long data_start = (unsigned long) &_sdata; 745 746 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 747 (end - start) >> 10); 748 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 749 750 kernel_set_to_readonly = 1; 751 752 /* 753 * The rodata section (but not the kernel text!) should also be 754 * not-executable. 755 */ 756 set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); 757 758 rodata_test(); 759 760 #ifdef CONFIG_CPA_DEBUG 761 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end); 762 set_memory_rw(start, (end-start) >> PAGE_SHIFT); 763 764 printk(KERN_INFO "Testing CPA: again\n"); 765 set_memory_ro(start, (end-start) >> PAGE_SHIFT); 766 #endif 767 768 free_init_pages("unused kernel memory", 769 (unsigned long) page_address(virt_to_page(text_end)), 770 (unsigned long) 771 page_address(virt_to_page(rodata_start))); 772 free_init_pages("unused kernel memory", 773 (unsigned long) page_address(virt_to_page(rodata_end)), 774 (unsigned long) page_address(virt_to_page(data_start))); 775 } 776 777 #endif 778 779 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len, 780 int flags) 781 { 782 #ifdef CONFIG_NUMA 783 int nid, next_nid; 784 int ret; 785 #endif 786 unsigned long pfn = phys >> PAGE_SHIFT; 787 788 if (pfn >= max_pfn) { 789 /* 790 * This can happen with kdump kernels when accessing 791 * firmware tables: 792 */ 793 if (pfn < max_pfn_mapped) 794 return -EFAULT; 795 796 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n", 797 phys, len); 798 return -EFAULT; 799 } 800 801 /* Should check here against the e820 map to avoid double free */ 802 #ifdef CONFIG_NUMA 803 nid = phys_to_nid(phys); 804 next_nid = phys_to_nid(phys + len - 1); 805 if (nid == next_nid) 806 ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags); 807 else 808 ret = reserve_bootmem(phys, len, flags); 809 810 if (ret != 0) 811 return ret; 812 813 #else 814 reserve_bootmem(phys, len, flags); 815 #endif 816 817 if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) { 818 dma_reserve += len / PAGE_SIZE; 819 set_dma_reserve(dma_reserve); 820 } 821 822 return 0; 823 } 824 825 int kern_addr_valid(unsigned long addr) 826 { 827 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; 828 pgd_t *pgd; 829 pud_t *pud; 830 pmd_t *pmd; 831 pte_t *pte; 832 833 if (above != 0 && above != -1UL) 834 return 0; 835 836 pgd = pgd_offset_k(addr); 837 if (pgd_none(*pgd)) 838 return 0; 839 840 pud = pud_offset(pgd, addr); 841 if (pud_none(*pud)) 842 return 0; 843 844 pmd = pmd_offset(pud, addr); 845 if (pmd_none(*pmd)) 846 return 0; 847 848 if (pmd_large(*pmd)) 849 return pfn_valid(pmd_pfn(*pmd)); 850 851 pte = pte_offset_kernel(pmd, addr); 852 if (pte_none(*pte)) 853 return 0; 854 855 return pfn_valid(pte_pfn(*pte)); 856 } 857 858 /* 859 * A pseudo VMA to allow ptrace access for the vsyscall page. This only 860 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does 861 * not need special handling anymore: 862 */ 863 static struct vm_area_struct gate_vma = { 864 .vm_start = VSYSCALL_START, 865 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE), 866 .vm_page_prot = PAGE_READONLY_EXEC, 867 .vm_flags = VM_READ | VM_EXEC 868 }; 869 870 struct vm_area_struct *get_gate_vma(struct task_struct *tsk) 871 { 872 #ifdef CONFIG_IA32_EMULATION 873 if (test_tsk_thread_flag(tsk, TIF_IA32)) 874 return NULL; 875 #endif 876 return &gate_vma; 877 } 878 879 int in_gate_area(struct task_struct *task, unsigned long addr) 880 { 881 struct vm_area_struct *vma = get_gate_vma(task); 882 883 if (!vma) 884 return 0; 885 886 return (addr >= vma->vm_start) && (addr < vma->vm_end); 887 } 888 889 /* 890 * Use this when you have no reliable task/vma, typically from interrupt 891 * context. It is less reliable than using the task's vma and may give 892 * false positives: 893 */ 894 int in_gate_area_no_task(unsigned long addr) 895 { 896 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END); 897 } 898 899 const char *arch_vma_name(struct vm_area_struct *vma) 900 { 901 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) 902 return "[vdso]"; 903 if (vma == &gate_vma) 904 return "[vsyscall]"; 905 return NULL; 906 } 907 908 #ifdef CONFIG_SPARSEMEM_VMEMMAP 909 /* 910 * Initialise the sparsemem vmemmap using huge-pages at the PMD level. 911 */ 912 static long __meminitdata addr_start, addr_end; 913 static void __meminitdata *p_start, *p_end; 914 static int __meminitdata node_start; 915 916 int __meminit 917 vmemmap_populate(struct page *start_page, unsigned long size, int node) 918 { 919 unsigned long addr = (unsigned long)start_page; 920 unsigned long end = (unsigned long)(start_page + size); 921 unsigned long next; 922 pgd_t *pgd; 923 pud_t *pud; 924 pmd_t *pmd; 925 926 for (; addr < end; addr = next) { 927 void *p = NULL; 928 929 pgd = vmemmap_pgd_populate(addr, node); 930 if (!pgd) 931 return -ENOMEM; 932 933 pud = vmemmap_pud_populate(pgd, addr, node); 934 if (!pud) 935 return -ENOMEM; 936 937 if (!cpu_has_pse) { 938 next = (addr + PAGE_SIZE) & PAGE_MASK; 939 pmd = vmemmap_pmd_populate(pud, addr, node); 940 941 if (!pmd) 942 return -ENOMEM; 943 944 p = vmemmap_pte_populate(pmd, addr, node); 945 946 if (!p) 947 return -ENOMEM; 948 949 addr_end = addr + PAGE_SIZE; 950 p_end = p + PAGE_SIZE; 951 } else { 952 next = pmd_addr_end(addr, end); 953 954 pmd = pmd_offset(pud, addr); 955 if (pmd_none(*pmd)) { 956 pte_t entry; 957 958 p = vmemmap_alloc_block(PMD_SIZE, node); 959 if (!p) 960 return -ENOMEM; 961 962 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, 963 PAGE_KERNEL_LARGE); 964 set_pmd(pmd, __pmd(pte_val(entry))); 965 966 /* check to see if we have contiguous blocks */ 967 if (p_end != p || node_start != node) { 968 if (p_start) 969 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 970 addr_start, addr_end-1, p_start, p_end-1, node_start); 971 addr_start = addr; 972 node_start = node; 973 p_start = p; 974 } 975 976 addr_end = addr + PMD_SIZE; 977 p_end = p + PMD_SIZE; 978 } else 979 vmemmap_verify((pte_t *)pmd, node, addr, next); 980 } 981 982 } 983 return 0; 984 } 985 986 void __meminit vmemmap_populate_print_last(void) 987 { 988 if (p_start) { 989 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 990 addr_start, addr_end-1, p_start, p_end-1, node_start); 991 p_start = NULL; 992 p_end = NULL; 993 node_start = 0; 994 } 995 } 996 #endif 997