init_64.c revision 774ea0bcb27f57b6fd521b3b6c43237782fed4b9
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/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#include <linux/bootmem.h> 55 56static int __init parse_direct_gbpages_off(char *arg) 57{ 58 direct_gbpages = 0; 59 return 0; 60} 61early_param("nogbpages", parse_direct_gbpages_off); 62 63static int __init parse_direct_gbpages_on(char *arg) 64{ 65 direct_gbpages = 1; 66 return 0; 67} 68early_param("gbpages", parse_direct_gbpages_on); 69 70/* 71 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the 72 * physical space so we can cache the place of the first one and move 73 * around without checking the pgd every time. 74 */ 75 76pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP; 77EXPORT_SYMBOL_GPL(__supported_pte_mask); 78 79int force_personality32; 80 81/* 82 * noexec32=on|off 83 * Control non executable heap for 32bit processes. 84 * To control the stack too use noexec=off 85 * 86 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default) 87 * off PROT_READ implies PROT_EXEC 88 */ 89static int __init nonx32_setup(char *str) 90{ 91 if (!strcmp(str, "on")) 92 force_personality32 &= ~READ_IMPLIES_EXEC; 93 else if (!strcmp(str, "off")) 94 force_personality32 |= READ_IMPLIES_EXEC; 95 return 1; 96} 97__setup("noexec32=", nonx32_setup); 98 99/* 100 * NOTE: This function is marked __ref because it calls __init function 101 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. 102 */ 103static __ref void *spp_getpage(void) 104{ 105 void *ptr; 106 107 if (after_bootmem) 108 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 109 else 110 ptr = alloc_bootmem_pages(PAGE_SIZE); 111 112 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) { 113 panic("set_pte_phys: cannot allocate page data %s\n", 114 after_bootmem ? "after bootmem" : ""); 115 } 116 117 pr_debug("spp_getpage %p\n", ptr); 118 119 return ptr; 120} 121 122static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr) 123{ 124 if (pgd_none(*pgd)) { 125 pud_t *pud = (pud_t *)spp_getpage(); 126 pgd_populate(&init_mm, pgd, pud); 127 if (pud != pud_offset(pgd, 0)) 128 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n", 129 pud, pud_offset(pgd, 0)); 130 } 131 return pud_offset(pgd, vaddr); 132} 133 134static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr) 135{ 136 if (pud_none(*pud)) { 137 pmd_t *pmd = (pmd_t *) spp_getpage(); 138 pud_populate(&init_mm, pud, pmd); 139 if (pmd != pmd_offset(pud, 0)) 140 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n", 141 pmd, pmd_offset(pud, 0)); 142 } 143 return pmd_offset(pud, vaddr); 144} 145 146static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr) 147{ 148 if (pmd_none(*pmd)) { 149 pte_t *pte = (pte_t *) spp_getpage(); 150 pmd_populate_kernel(&init_mm, pmd, pte); 151 if (pte != pte_offset_kernel(pmd, 0)) 152 printk(KERN_ERR "PAGETABLE BUG #02!\n"); 153 } 154 return pte_offset_kernel(pmd, vaddr); 155} 156 157void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte) 158{ 159 pud_t *pud; 160 pmd_t *pmd; 161 pte_t *pte; 162 163 pud = pud_page + pud_index(vaddr); 164 pmd = fill_pmd(pud, vaddr); 165 pte = fill_pte(pmd, vaddr); 166 167 set_pte(pte, new_pte); 168 169 /* 170 * It's enough to flush this one mapping. 171 * (PGE mappings get flushed as well) 172 */ 173 __flush_tlb_one(vaddr); 174} 175 176void set_pte_vaddr(unsigned long vaddr, pte_t pteval) 177{ 178 pgd_t *pgd; 179 pud_t *pud_page; 180 181 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval)); 182 183 pgd = pgd_offset_k(vaddr); 184 if (pgd_none(*pgd)) { 185 printk(KERN_ERR 186 "PGD FIXMAP MISSING, it should be setup in head.S!\n"); 187 return; 188 } 189 pud_page = (pud_t*)pgd_page_vaddr(*pgd); 190 set_pte_vaddr_pud(pud_page, vaddr, pteval); 191} 192 193pmd_t * __init populate_extra_pmd(unsigned long vaddr) 194{ 195 pgd_t *pgd; 196 pud_t *pud; 197 198 pgd = pgd_offset_k(vaddr); 199 pud = fill_pud(pgd, vaddr); 200 return fill_pmd(pud, vaddr); 201} 202 203pte_t * __init populate_extra_pte(unsigned long vaddr) 204{ 205 pmd_t *pmd; 206 207 pmd = populate_extra_pmd(vaddr); 208 return fill_pte(pmd, vaddr); 209} 210 211/* 212 * Create large page table mappings for a range of physical addresses. 213 */ 214static void __init __init_extra_mapping(unsigned long phys, unsigned long size, 215 pgprot_t prot) 216{ 217 pgd_t *pgd; 218 pud_t *pud; 219 pmd_t *pmd; 220 221 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK)); 222 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) { 223 pgd = pgd_offset_k((unsigned long)__va(phys)); 224 if (pgd_none(*pgd)) { 225 pud = (pud_t *) spp_getpage(); 226 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE | 227 _PAGE_USER)); 228 } 229 pud = pud_offset(pgd, (unsigned long)__va(phys)); 230 if (pud_none(*pud)) { 231 pmd = (pmd_t *) spp_getpage(); 232 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | 233 _PAGE_USER)); 234 } 235 pmd = pmd_offset(pud, phys); 236 BUG_ON(!pmd_none(*pmd)); 237 set_pmd(pmd, __pmd(phys | pgprot_val(prot))); 238 } 239} 240 241void __init init_extra_mapping_wb(unsigned long phys, unsigned long size) 242{ 243 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE); 244} 245 246void __init init_extra_mapping_uc(unsigned long phys, unsigned long size) 247{ 248 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE); 249} 250 251/* 252 * The head.S code sets up the kernel high mapping: 253 * 254 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text) 255 * 256 * phys_addr holds the negative offset to the kernel, which is added 257 * to the compile time generated pmds. This results in invalid pmds up 258 * to the point where we hit the physaddr 0 mapping. 259 * 260 * We limit the mappings to the region from _text to _end. _end is 261 * rounded up to the 2MB boundary. This catches the invalid pmds as 262 * well, as they are located before _text: 263 */ 264void __init cleanup_highmap(void) 265{ 266 unsigned long vaddr = __START_KERNEL_map; 267 unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1; 268 pmd_t *pmd = level2_kernel_pgt; 269 pmd_t *last_pmd = pmd + PTRS_PER_PMD; 270 271 for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) { 272 if (pmd_none(*pmd)) 273 continue; 274 if (vaddr < (unsigned long) _text || vaddr > end) 275 set_pmd(pmd, __pmd(0)); 276 } 277} 278 279static __ref void *alloc_low_page(unsigned long *phys) 280{ 281 unsigned long pfn = e820_table_end++; 282 void *adr; 283 284 if (after_bootmem) { 285 adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 286 *phys = __pa(adr); 287 288 return adr; 289 } 290 291 if (pfn >= e820_table_top) 292 panic("alloc_low_page: ran out of memory"); 293 294 adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE); 295 memset(adr, 0, PAGE_SIZE); 296 *phys = pfn * PAGE_SIZE; 297 return adr; 298} 299 300static __ref void unmap_low_page(void *adr) 301{ 302 if (after_bootmem) 303 return; 304 305 early_iounmap(adr, PAGE_SIZE); 306} 307 308static unsigned long __meminit 309phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, 310 pgprot_t prot) 311{ 312 unsigned pages = 0; 313 unsigned long last_map_addr = end; 314 int i; 315 316 pte_t *pte = pte_page + pte_index(addr); 317 318 for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { 319 320 if (addr >= end) { 321 if (!after_bootmem) { 322 for(; i < PTRS_PER_PTE; i++, pte++) 323 set_pte(pte, __pte(0)); 324 } 325 break; 326 } 327 328 /* 329 * We will re-use the existing mapping. 330 * Xen for example has some special requirements, like mapping 331 * pagetable pages as RO. So assume someone who pre-setup 332 * these mappings are more intelligent. 333 */ 334 if (pte_val(*pte)) { 335 pages++; 336 continue; 337 } 338 339 if (0) 340 printk(" pte=%p addr=%lx pte=%016lx\n", 341 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); 342 pages++; 343 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot)); 344 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; 345 } 346 347 update_page_count(PG_LEVEL_4K, pages); 348 349 return last_map_addr; 350} 351 352static unsigned long __meminit 353phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end, 354 pgprot_t prot) 355{ 356 pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd); 357 358 return phys_pte_init(pte, address, end, prot); 359} 360 361static unsigned long __meminit 362phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 363 unsigned long page_size_mask, pgprot_t prot) 364{ 365 unsigned long pages = 0; 366 unsigned long last_map_addr = end; 367 368 int i = pmd_index(address); 369 370 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) { 371 unsigned long pte_phys; 372 pmd_t *pmd = pmd_page + pmd_index(address); 373 pte_t *pte; 374 pgprot_t new_prot = prot; 375 376 if (address >= end) { 377 if (!after_bootmem) { 378 for (; i < PTRS_PER_PMD; i++, pmd++) 379 set_pmd(pmd, __pmd(0)); 380 } 381 break; 382 } 383 384 if (pmd_val(*pmd)) { 385 if (!pmd_large(*pmd)) { 386 spin_lock(&init_mm.page_table_lock); 387 last_map_addr = phys_pte_update(pmd, address, 388 end, prot); 389 spin_unlock(&init_mm.page_table_lock); 390 continue; 391 } 392 /* 393 * If we are ok with PG_LEVEL_2M mapping, then we will 394 * use the existing mapping, 395 * 396 * Otherwise, we will split the large page mapping but 397 * use the same existing protection bits except for 398 * large page, so that we don't violate Intel's TLB 399 * Application note (317080) which says, while changing 400 * the page sizes, new and old translations should 401 * not differ with respect to page frame and 402 * attributes. 403 */ 404 if (page_size_mask & (1 << PG_LEVEL_2M)) { 405 pages++; 406 continue; 407 } 408 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); 409 } 410 411 if (page_size_mask & (1<<PG_LEVEL_2M)) { 412 pages++; 413 spin_lock(&init_mm.page_table_lock); 414 set_pte((pte_t *)pmd, 415 pfn_pte(address >> PAGE_SHIFT, 416 __pgprot(pgprot_val(prot) | _PAGE_PSE))); 417 spin_unlock(&init_mm.page_table_lock); 418 last_map_addr = (address & PMD_MASK) + PMD_SIZE; 419 continue; 420 } 421 422 pte = alloc_low_page(&pte_phys); 423 last_map_addr = phys_pte_init(pte, address, end, new_prot); 424 unmap_low_page(pte); 425 426 spin_lock(&init_mm.page_table_lock); 427 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); 428 spin_unlock(&init_mm.page_table_lock); 429 } 430 update_page_count(PG_LEVEL_2M, pages); 431 return last_map_addr; 432} 433 434static unsigned long __meminit 435phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end, 436 unsigned long page_size_mask, pgprot_t prot) 437{ 438 pmd_t *pmd = pmd_offset(pud, 0); 439 unsigned long last_map_addr; 440 441 last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot); 442 __flush_tlb_all(); 443 return last_map_addr; 444} 445 446static unsigned long __meminit 447phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 448 unsigned long page_size_mask) 449{ 450 unsigned long pages = 0; 451 unsigned long last_map_addr = end; 452 int i = pud_index(addr); 453 454 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) { 455 unsigned long pmd_phys; 456 pud_t *pud = pud_page + pud_index(addr); 457 pmd_t *pmd; 458 pgprot_t prot = PAGE_KERNEL; 459 460 if (addr >= end) 461 break; 462 463 if (!after_bootmem && 464 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) { 465 set_pud(pud, __pud(0)); 466 continue; 467 } 468 469 if (pud_val(*pud)) { 470 if (!pud_large(*pud)) { 471 last_map_addr = phys_pmd_update(pud, addr, end, 472 page_size_mask, prot); 473 continue; 474 } 475 /* 476 * If we are ok with PG_LEVEL_1G mapping, then we will 477 * use the existing mapping. 478 * 479 * Otherwise, we will split the gbpage mapping but use 480 * the same existing protection bits except for large 481 * page, so that we don't violate Intel's TLB 482 * Application note (317080) which says, while changing 483 * the page sizes, new and old translations should 484 * not differ with respect to page frame and 485 * attributes. 486 */ 487 if (page_size_mask & (1 << PG_LEVEL_1G)) { 488 pages++; 489 continue; 490 } 491 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); 492 } 493 494 if (page_size_mask & (1<<PG_LEVEL_1G)) { 495 pages++; 496 spin_lock(&init_mm.page_table_lock); 497 set_pte((pte_t *)pud, 498 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); 499 spin_unlock(&init_mm.page_table_lock); 500 last_map_addr = (addr & PUD_MASK) + PUD_SIZE; 501 continue; 502 } 503 504 pmd = alloc_low_page(&pmd_phys); 505 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, 506 prot); 507 unmap_low_page(pmd); 508 509 spin_lock(&init_mm.page_table_lock); 510 pud_populate(&init_mm, pud, __va(pmd_phys)); 511 spin_unlock(&init_mm.page_table_lock); 512 } 513 __flush_tlb_all(); 514 515 update_page_count(PG_LEVEL_1G, pages); 516 517 return last_map_addr; 518} 519 520static unsigned long __meminit 521phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end, 522 unsigned long page_size_mask) 523{ 524 pud_t *pud; 525 526 pud = (pud_t *)pgd_page_vaddr(*pgd); 527 528 return phys_pud_init(pud, addr, end, page_size_mask); 529} 530 531unsigned long __meminit 532kernel_physical_mapping_init(unsigned long start, 533 unsigned long end, 534 unsigned long page_size_mask) 535{ 536 537 unsigned long next, last_map_addr = end; 538 539 start = (unsigned long)__va(start); 540 end = (unsigned long)__va(end); 541 542 for (; start < end; start = next) { 543 pgd_t *pgd = pgd_offset_k(start); 544 unsigned long pud_phys; 545 pud_t *pud; 546 547 next = (start + PGDIR_SIZE) & PGDIR_MASK; 548 if (next > end) 549 next = end; 550 551 if (pgd_val(*pgd)) { 552 last_map_addr = phys_pud_update(pgd, __pa(start), 553 __pa(end), page_size_mask); 554 continue; 555 } 556 557 pud = alloc_low_page(&pud_phys); 558 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next), 559 page_size_mask); 560 unmap_low_page(pud); 561 562 spin_lock(&init_mm.page_table_lock); 563 pgd_populate(&init_mm, pgd, __va(pud_phys)); 564 spin_unlock(&init_mm.page_table_lock); 565 } 566 __flush_tlb_all(); 567 568 return last_map_addr; 569} 570 571#ifndef CONFIG_NUMA 572void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn, 573 int acpi, int k8) 574{ 575 memblock_x86_register_active_regions(0, start_pfn, end_pfn); 576} 577#endif 578 579void __init paging_init(void) 580{ 581 unsigned long max_zone_pfns[MAX_NR_ZONES]; 582 583 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 584 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN; 585 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN; 586 max_zone_pfns[ZONE_NORMAL] = max_pfn; 587 588 sparse_memory_present_with_active_regions(MAX_NUMNODES); 589 sparse_init(); 590 591 /* 592 * clear the default setting with node 0 593 * note: don't use nodes_clear here, that is really clearing when 594 * numa support is not compiled in, and later node_set_state 595 * will not set it back. 596 */ 597 node_clear_state(0, N_NORMAL_MEMORY); 598 599 free_area_init_nodes(max_zone_pfns); 600} 601 602/* 603 * Memory hotplug specific functions 604 */ 605#ifdef CONFIG_MEMORY_HOTPLUG 606/* 607 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need 608 * updating. 609 */ 610static void update_end_of_memory_vars(u64 start, u64 size) 611{ 612 unsigned long end_pfn = PFN_UP(start + size); 613 614 if (end_pfn > max_pfn) { 615 max_pfn = end_pfn; 616 max_low_pfn = end_pfn; 617 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; 618 } 619} 620 621/* 622 * Memory is added always to NORMAL zone. This means you will never get 623 * additional DMA/DMA32 memory. 624 */ 625int arch_add_memory(int nid, u64 start, u64 size) 626{ 627 struct pglist_data *pgdat = NODE_DATA(nid); 628 struct zone *zone = pgdat->node_zones + ZONE_NORMAL; 629 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT; 630 unsigned long nr_pages = size >> PAGE_SHIFT; 631 int ret; 632 633 last_mapped_pfn = init_memory_mapping(start, start + size); 634 if (last_mapped_pfn > max_pfn_mapped) 635 max_pfn_mapped = last_mapped_pfn; 636 637 ret = __add_pages(nid, zone, start_pfn, nr_pages); 638 WARN_ON_ONCE(ret); 639 640 /* update max_pfn, max_low_pfn and high_memory */ 641 update_end_of_memory_vars(start, size); 642 643 return ret; 644} 645EXPORT_SYMBOL_GPL(arch_add_memory); 646 647#if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA) 648int memory_add_physaddr_to_nid(u64 start) 649{ 650 return 0; 651} 652EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); 653#endif 654 655#endif /* CONFIG_MEMORY_HOTPLUG */ 656 657static struct kcore_list kcore_vsyscall; 658 659void __init mem_init(void) 660{ 661 long codesize, reservedpages, datasize, initsize; 662 unsigned long absent_pages; 663 664 pci_iommu_alloc(); 665 666 /* clear_bss() already clear the empty_zero_page */ 667 668 reservedpages = 0; 669 670 /* this will put all low memory onto the freelists */ 671#ifdef CONFIG_NUMA 672 totalram_pages = numa_free_all_bootmem(); 673#else 674 totalram_pages = free_all_bootmem(); 675#endif 676 677 absent_pages = absent_pages_in_range(0, max_pfn); 678 reservedpages = max_pfn - totalram_pages - absent_pages; 679 after_bootmem = 1; 680 681 codesize = (unsigned long) &_etext - (unsigned long) &_text; 682 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 683 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 684 685 /* Register memory areas for /proc/kcore */ 686 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, 687 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER); 688 689 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, " 690 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n", 691 nr_free_pages() << (PAGE_SHIFT-10), 692 max_pfn << (PAGE_SHIFT-10), 693 codesize >> 10, 694 absent_pages << (PAGE_SHIFT-10), 695 reservedpages << (PAGE_SHIFT-10), 696 datasize >> 10, 697 initsize >> 10); 698} 699 700#ifdef CONFIG_DEBUG_RODATA 701const int rodata_test_data = 0xC3; 702EXPORT_SYMBOL_GPL(rodata_test_data); 703 704int kernel_set_to_readonly; 705 706void set_kernel_text_rw(void) 707{ 708 unsigned long start = PFN_ALIGN(_text); 709 unsigned long end = PFN_ALIGN(__stop___ex_table); 710 711 if (!kernel_set_to_readonly) 712 return; 713 714 pr_debug("Set kernel text: %lx - %lx for read write\n", 715 start, end); 716 717 /* 718 * Make the kernel identity mapping for text RW. Kernel text 719 * mapping will always be RO. Refer to the comment in 720 * static_protections() in pageattr.c 721 */ 722 set_memory_rw(start, (end - start) >> PAGE_SHIFT); 723} 724 725void set_kernel_text_ro(void) 726{ 727 unsigned long start = PFN_ALIGN(_text); 728 unsigned long end = PFN_ALIGN(__stop___ex_table); 729 730 if (!kernel_set_to_readonly) 731 return; 732 733 pr_debug("Set kernel text: %lx - %lx for read only\n", 734 start, end); 735 736 /* 737 * Set the kernel identity mapping for text RO. 738 */ 739 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 740} 741 742void mark_rodata_ro(void) 743{ 744 unsigned long start = PFN_ALIGN(_text); 745 unsigned long rodata_start = 746 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; 747 unsigned long end = (unsigned long) &__end_rodata_hpage_align; 748 unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table); 749 unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata); 750 unsigned long data_start = (unsigned long) &_sdata; 751 752 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 753 (end - start) >> 10); 754 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 755 756 kernel_set_to_readonly = 1; 757 758 /* 759 * The rodata section (but not the kernel text!) should also be 760 * not-executable. 761 */ 762 set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); 763 764 rodata_test(); 765 766#ifdef CONFIG_CPA_DEBUG 767 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end); 768 set_memory_rw(start, (end-start) >> PAGE_SHIFT); 769 770 printk(KERN_INFO "Testing CPA: again\n"); 771 set_memory_ro(start, (end-start) >> PAGE_SHIFT); 772#endif 773 774 free_init_pages("unused kernel memory", 775 (unsigned long) page_address(virt_to_page(text_end)), 776 (unsigned long) 777 page_address(virt_to_page(rodata_start))); 778 free_init_pages("unused kernel memory", 779 (unsigned long) page_address(virt_to_page(rodata_end)), 780 (unsigned long) page_address(virt_to_page(data_start))); 781} 782 783#endif 784 785int kern_addr_valid(unsigned long addr) 786{ 787 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; 788 pgd_t *pgd; 789 pud_t *pud; 790 pmd_t *pmd; 791 pte_t *pte; 792 793 if (above != 0 && above != -1UL) 794 return 0; 795 796 pgd = pgd_offset_k(addr); 797 if (pgd_none(*pgd)) 798 return 0; 799 800 pud = pud_offset(pgd, addr); 801 if (pud_none(*pud)) 802 return 0; 803 804 pmd = pmd_offset(pud, addr); 805 if (pmd_none(*pmd)) 806 return 0; 807 808 if (pmd_large(*pmd)) 809 return pfn_valid(pmd_pfn(*pmd)); 810 811 pte = pte_offset_kernel(pmd, addr); 812 if (pte_none(*pte)) 813 return 0; 814 815 return pfn_valid(pte_pfn(*pte)); 816} 817 818/* 819 * A pseudo VMA to allow ptrace access for the vsyscall page. This only 820 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does 821 * not need special handling anymore: 822 */ 823static struct vm_area_struct gate_vma = { 824 .vm_start = VSYSCALL_START, 825 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE), 826 .vm_page_prot = PAGE_READONLY_EXEC, 827 .vm_flags = VM_READ | VM_EXEC 828}; 829 830struct vm_area_struct *get_gate_vma(struct task_struct *tsk) 831{ 832#ifdef CONFIG_IA32_EMULATION 833 if (test_tsk_thread_flag(tsk, TIF_IA32)) 834 return NULL; 835#endif 836 return &gate_vma; 837} 838 839int in_gate_area(struct task_struct *task, unsigned long addr) 840{ 841 struct vm_area_struct *vma = get_gate_vma(task); 842 843 if (!vma) 844 return 0; 845 846 return (addr >= vma->vm_start) && (addr < vma->vm_end); 847} 848 849/* 850 * Use this when you have no reliable task/vma, typically from interrupt 851 * context. It is less reliable than using the task's vma and may give 852 * false positives: 853 */ 854int in_gate_area_no_task(unsigned long addr) 855{ 856 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END); 857} 858 859const char *arch_vma_name(struct vm_area_struct *vma) 860{ 861 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) 862 return "[vdso]"; 863 if (vma == &gate_vma) 864 return "[vsyscall]"; 865 return NULL; 866} 867 868#ifdef CONFIG_SPARSEMEM_VMEMMAP 869/* 870 * Initialise the sparsemem vmemmap using huge-pages at the PMD level. 871 */ 872static long __meminitdata addr_start, addr_end; 873static void __meminitdata *p_start, *p_end; 874static int __meminitdata node_start; 875 876int __meminit 877vmemmap_populate(struct page *start_page, unsigned long size, int node) 878{ 879 unsigned long addr = (unsigned long)start_page; 880 unsigned long end = (unsigned long)(start_page + size); 881 unsigned long next; 882 pgd_t *pgd; 883 pud_t *pud; 884 pmd_t *pmd; 885 886 for (; addr < end; addr = next) { 887 void *p = NULL; 888 889 pgd = vmemmap_pgd_populate(addr, node); 890 if (!pgd) 891 return -ENOMEM; 892 893 pud = vmemmap_pud_populate(pgd, addr, node); 894 if (!pud) 895 return -ENOMEM; 896 897 if (!cpu_has_pse) { 898 next = (addr + PAGE_SIZE) & PAGE_MASK; 899 pmd = vmemmap_pmd_populate(pud, addr, node); 900 901 if (!pmd) 902 return -ENOMEM; 903 904 p = vmemmap_pte_populate(pmd, addr, node); 905 906 if (!p) 907 return -ENOMEM; 908 909 addr_end = addr + PAGE_SIZE; 910 p_end = p + PAGE_SIZE; 911 } else { 912 next = pmd_addr_end(addr, end); 913 914 pmd = pmd_offset(pud, addr); 915 if (pmd_none(*pmd)) { 916 pte_t entry; 917 918 p = vmemmap_alloc_block_buf(PMD_SIZE, node); 919 if (!p) 920 return -ENOMEM; 921 922 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, 923 PAGE_KERNEL_LARGE); 924 set_pmd(pmd, __pmd(pte_val(entry))); 925 926 /* check to see if we have contiguous blocks */ 927 if (p_end != p || node_start != node) { 928 if (p_start) 929 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 930 addr_start, addr_end-1, p_start, p_end-1, node_start); 931 addr_start = addr; 932 node_start = node; 933 p_start = p; 934 } 935 936 addr_end = addr + PMD_SIZE; 937 p_end = p + PMD_SIZE; 938 } else 939 vmemmap_verify((pte_t *)pmd, node, addr, next); 940 } 941 942 } 943 return 0; 944} 945 946void __meminit vmemmap_populate_print_last(void) 947{ 948 if (p_start) { 949 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 950 addr_start, addr_end-1, p_start, p_end-1, node_start); 951 p_start = NULL; 952 p_end = NULL; 953 node_start = 0; 954 } 955} 956#endif 957