init_64.c revision a63fdc5156f2ef5690b6cf03d72b0c4917efbba7
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.h> 32#include <linux/memory_hotplug.h> 33#include <linux/nmi.h> 34#include <linux/gfp.h> 35 36#include <asm/processor.h> 37#include <asm/bios_ebda.h> 38#include <asm/system.h> 39#include <asm/uaccess.h> 40#include <asm/pgtable.h> 41#include <asm/pgalloc.h> 42#include <asm/dma.h> 43#include <asm/fixmap.h> 44#include <asm/e820.h> 45#include <asm/apic.h> 46#include <asm/tlb.h> 47#include <asm/mmu_context.h> 48#include <asm/proto.h> 49#include <asm/smp.h> 50#include <asm/sections.h> 51#include <asm/kdebug.h> 52#include <asm/numa.h> 53#include <asm/cacheflush.h> 54#include <asm/init.h> 55#include <asm/uv/uv.h> 56#include <asm/setup.h> 57 58static int __init parse_direct_gbpages_off(char *arg) 59{ 60 direct_gbpages = 0; 61 return 0; 62} 63early_param("nogbpages", parse_direct_gbpages_off); 64 65static int __init parse_direct_gbpages_on(char *arg) 66{ 67 direct_gbpages = 1; 68 return 0; 69} 70early_param("gbpages", parse_direct_gbpages_on); 71 72/* 73 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the 74 * physical space so we can cache the place of the first one and move 75 * around without checking the pgd every time. 76 */ 77 78pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP; 79EXPORT_SYMBOL_GPL(__supported_pte_mask); 80 81int force_personality32; 82 83/* 84 * noexec32=on|off 85 * Control non executable heap for 32bit processes. 86 * To control the stack too use noexec=off 87 * 88 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default) 89 * off PROT_READ implies PROT_EXEC 90 */ 91static int __init nonx32_setup(char *str) 92{ 93 if (!strcmp(str, "on")) 94 force_personality32 &= ~READ_IMPLIES_EXEC; 95 else if (!strcmp(str, "off")) 96 force_personality32 |= READ_IMPLIES_EXEC; 97 return 1; 98} 99__setup("noexec32=", nonx32_setup); 100 101/* 102 * When memory was added/removed make sure all the processes MM have 103 * suitable PGD entries in the local PGD level page. 104 */ 105void sync_global_pgds(unsigned long start, unsigned long end) 106{ 107 unsigned long address; 108 109 for (address = start; address <= end; address += PGDIR_SIZE) { 110 const pgd_t *pgd_ref = pgd_offset_k(address); 111 struct page *page; 112 113 if (pgd_none(*pgd_ref)) 114 continue; 115 116 spin_lock(&pgd_lock); 117 list_for_each_entry(page, &pgd_list, lru) { 118 pgd_t *pgd; 119 spinlock_t *pgt_lock; 120 121 pgd = (pgd_t *)page_address(page) + pgd_index(address); 122 /* the pgt_lock only for Xen */ 123 pgt_lock = &pgd_page_get_mm(page)->page_table_lock; 124 spin_lock(pgt_lock); 125 126 if (pgd_none(*pgd)) 127 set_pgd(pgd, *pgd_ref); 128 else 129 BUG_ON(pgd_page_vaddr(*pgd) 130 != pgd_page_vaddr(*pgd_ref)); 131 132 spin_unlock(pgt_lock); 133 } 134 spin_unlock(&pgd_lock); 135 } 136} 137 138/* 139 * NOTE: This function is marked __ref because it calls __init function 140 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. 141 */ 142static __ref void *spp_getpage(void) 143{ 144 void *ptr; 145 146 if (after_bootmem) 147 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 148 else 149 ptr = alloc_bootmem_pages(PAGE_SIZE); 150 151 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) { 152 panic("set_pte_phys: cannot allocate page data %s\n", 153 after_bootmem ? "after bootmem" : ""); 154 } 155 156 pr_debug("spp_getpage %p\n", ptr); 157 158 return ptr; 159} 160 161static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr) 162{ 163 if (pgd_none(*pgd)) { 164 pud_t *pud = (pud_t *)spp_getpage(); 165 pgd_populate(&init_mm, pgd, pud); 166 if (pud != pud_offset(pgd, 0)) 167 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n", 168 pud, pud_offset(pgd, 0)); 169 } 170 return pud_offset(pgd, vaddr); 171} 172 173static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr) 174{ 175 if (pud_none(*pud)) { 176 pmd_t *pmd = (pmd_t *) spp_getpage(); 177 pud_populate(&init_mm, pud, pmd); 178 if (pmd != pmd_offset(pud, 0)) 179 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n", 180 pmd, pmd_offset(pud, 0)); 181 } 182 return pmd_offset(pud, vaddr); 183} 184 185static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr) 186{ 187 if (pmd_none(*pmd)) { 188 pte_t *pte = (pte_t *) spp_getpage(); 189 pmd_populate_kernel(&init_mm, pmd, pte); 190 if (pte != pte_offset_kernel(pmd, 0)) 191 printk(KERN_ERR "PAGETABLE BUG #02!\n"); 192 } 193 return pte_offset_kernel(pmd, vaddr); 194} 195 196void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte) 197{ 198 pud_t *pud; 199 pmd_t *pmd; 200 pte_t *pte; 201 202 pud = pud_page + pud_index(vaddr); 203 pmd = fill_pmd(pud, vaddr); 204 pte = fill_pte(pmd, vaddr); 205 206 set_pte(pte, new_pte); 207 208 /* 209 * It's enough to flush this one mapping. 210 * (PGE mappings get flushed as well) 211 */ 212 __flush_tlb_one(vaddr); 213} 214 215void set_pte_vaddr(unsigned long vaddr, pte_t pteval) 216{ 217 pgd_t *pgd; 218 pud_t *pud_page; 219 220 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval)); 221 222 pgd = pgd_offset_k(vaddr); 223 if (pgd_none(*pgd)) { 224 printk(KERN_ERR 225 "PGD FIXMAP MISSING, it should be setup in head.S!\n"); 226 return; 227 } 228 pud_page = (pud_t*)pgd_page_vaddr(*pgd); 229 set_pte_vaddr_pud(pud_page, vaddr, pteval); 230} 231 232pmd_t * __init populate_extra_pmd(unsigned long vaddr) 233{ 234 pgd_t *pgd; 235 pud_t *pud; 236 237 pgd = pgd_offset_k(vaddr); 238 pud = fill_pud(pgd, vaddr); 239 return fill_pmd(pud, vaddr); 240} 241 242pte_t * __init populate_extra_pte(unsigned long vaddr) 243{ 244 pmd_t *pmd; 245 246 pmd = populate_extra_pmd(vaddr); 247 return fill_pte(pmd, vaddr); 248} 249 250/* 251 * Create large page table mappings for a range of physical addresses. 252 */ 253static void __init __init_extra_mapping(unsigned long phys, unsigned long size, 254 pgprot_t prot) 255{ 256 pgd_t *pgd; 257 pud_t *pud; 258 pmd_t *pmd; 259 260 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK)); 261 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) { 262 pgd = pgd_offset_k((unsigned long)__va(phys)); 263 if (pgd_none(*pgd)) { 264 pud = (pud_t *) spp_getpage(); 265 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE | 266 _PAGE_USER)); 267 } 268 pud = pud_offset(pgd, (unsigned long)__va(phys)); 269 if (pud_none(*pud)) { 270 pmd = (pmd_t *) spp_getpage(); 271 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | 272 _PAGE_USER)); 273 } 274 pmd = pmd_offset(pud, phys); 275 BUG_ON(!pmd_none(*pmd)); 276 set_pmd(pmd, __pmd(phys | pgprot_val(prot))); 277 } 278} 279 280void __init init_extra_mapping_wb(unsigned long phys, unsigned long size) 281{ 282 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE); 283} 284 285void __init init_extra_mapping_uc(unsigned long phys, unsigned long size) 286{ 287 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE); 288} 289 290/* 291 * The head.S code sets up the kernel high mapping: 292 * 293 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text) 294 * 295 * phys_addr holds the negative offset to the kernel, which is added 296 * to the compile time generated pmds. This results in invalid pmds up 297 * to the point where we hit the physaddr 0 mapping. 298 * 299 * We limit the mappings to the region from _text to _brk_end. _brk_end 300 * is rounded up to the 2MB boundary. This catches the invalid pmds as 301 * well, as they are located before _text: 302 */ 303void __init cleanup_highmap(void) 304{ 305 unsigned long vaddr = __START_KERNEL_map; 306 unsigned long vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT); 307 unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1; 308 pmd_t *pmd = level2_kernel_pgt; 309 310 for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) { 311 if (pmd_none(*pmd)) 312 continue; 313 if (vaddr < (unsigned long) _text || vaddr > end) 314 set_pmd(pmd, __pmd(0)); 315 } 316} 317 318static __ref void *alloc_low_page(unsigned long *phys) 319{ 320 unsigned long pfn = pgt_buf_end++; 321 void *adr; 322 323 if (after_bootmem) { 324 adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 325 *phys = __pa(adr); 326 327 return adr; 328 } 329 330 if (pfn >= pgt_buf_top) 331 panic("alloc_low_page: ran out of memory"); 332 333 adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE); 334 clear_page(adr); 335 *phys = pfn * PAGE_SIZE; 336 return adr; 337} 338 339static __ref void *map_low_page(void *virt) 340{ 341 void *adr; 342 unsigned long phys, left; 343 344 if (after_bootmem) 345 return virt; 346 347 phys = __pa(virt); 348 left = phys & (PAGE_SIZE - 1); 349 adr = early_memremap(phys & PAGE_MASK, PAGE_SIZE); 350 adr = (void *)(((unsigned long)adr) | left); 351 352 return adr; 353} 354 355static __ref void unmap_low_page(void *adr) 356{ 357 if (after_bootmem) 358 return; 359 360 early_iounmap((void *)((unsigned long)adr & PAGE_MASK), PAGE_SIZE); 361} 362 363static unsigned long __meminit 364phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, 365 pgprot_t prot) 366{ 367 unsigned pages = 0; 368 unsigned long last_map_addr = end; 369 int i; 370 371 pte_t *pte = pte_page + pte_index(addr); 372 373 for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { 374 375 if (addr >= end) { 376 if (!after_bootmem) { 377 for(; i < PTRS_PER_PTE; i++, pte++) 378 set_pte(pte, __pte(0)); 379 } 380 break; 381 } 382 383 /* 384 * We will re-use the existing mapping. 385 * Xen for example has some special requirements, like mapping 386 * pagetable pages as RO. So assume someone who pre-setup 387 * these mappings are more intelligent. 388 */ 389 if (pte_val(*pte)) { 390 pages++; 391 continue; 392 } 393 394 if (0) 395 printk(" pte=%p addr=%lx pte=%016lx\n", 396 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); 397 pages++; 398 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot)); 399 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; 400 } 401 402 update_page_count(PG_LEVEL_4K, pages); 403 404 return last_map_addr; 405} 406 407static unsigned long __meminit 408phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 409 unsigned long page_size_mask, pgprot_t prot) 410{ 411 unsigned long pages = 0; 412 unsigned long last_map_addr = end; 413 414 int i = pmd_index(address); 415 416 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) { 417 unsigned long pte_phys; 418 pmd_t *pmd = pmd_page + pmd_index(address); 419 pte_t *pte; 420 pgprot_t new_prot = prot; 421 422 if (address >= end) { 423 if (!after_bootmem) { 424 for (; i < PTRS_PER_PMD; i++, pmd++) 425 set_pmd(pmd, __pmd(0)); 426 } 427 break; 428 } 429 430 if (pmd_val(*pmd)) { 431 if (!pmd_large(*pmd)) { 432 spin_lock(&init_mm.page_table_lock); 433 pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); 434 last_map_addr = phys_pte_init(pte, address, 435 end, prot); 436 unmap_low_page(pte); 437 spin_unlock(&init_mm.page_table_lock); 438 continue; 439 } 440 /* 441 * If we are ok with PG_LEVEL_2M mapping, then we will 442 * use the existing mapping, 443 * 444 * Otherwise, we will split the large page mapping but 445 * use the same existing protection bits except for 446 * large page, so that we don't violate Intel's TLB 447 * Application note (317080) which says, while changing 448 * the page sizes, new and old translations should 449 * not differ with respect to page frame and 450 * attributes. 451 */ 452 if (page_size_mask & (1 << PG_LEVEL_2M)) { 453 pages++; 454 continue; 455 } 456 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); 457 } 458 459 if (page_size_mask & (1<<PG_LEVEL_2M)) { 460 pages++; 461 spin_lock(&init_mm.page_table_lock); 462 set_pte((pte_t *)pmd, 463 pfn_pte(address >> PAGE_SHIFT, 464 __pgprot(pgprot_val(prot) | _PAGE_PSE))); 465 spin_unlock(&init_mm.page_table_lock); 466 last_map_addr = (address & PMD_MASK) + PMD_SIZE; 467 continue; 468 } 469 470 pte = alloc_low_page(&pte_phys); 471 last_map_addr = phys_pte_init(pte, address, end, new_prot); 472 unmap_low_page(pte); 473 474 spin_lock(&init_mm.page_table_lock); 475 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); 476 spin_unlock(&init_mm.page_table_lock); 477 } 478 update_page_count(PG_LEVEL_2M, pages); 479 return last_map_addr; 480} 481 482static unsigned long __meminit 483phys_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 pmd = map_low_page(pmd_offset(pud, 0)); 508 last_map_addr = phys_pmd_init(pmd, addr, end, 509 page_size_mask, prot); 510 unmap_low_page(pmd); 511 __flush_tlb_all(); 512 continue; 513 } 514 /* 515 * If we are ok with PG_LEVEL_1G mapping, then we will 516 * use the existing mapping. 517 * 518 * Otherwise, we will split the gbpage mapping but use 519 * the same existing protection bits except for large 520 * page, so that we don't violate Intel's TLB 521 * Application note (317080) which says, while changing 522 * the page sizes, new and old translations should 523 * not differ with respect to page frame and 524 * attributes. 525 */ 526 if (page_size_mask & (1 << PG_LEVEL_1G)) { 527 pages++; 528 continue; 529 } 530 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); 531 } 532 533 if (page_size_mask & (1<<PG_LEVEL_1G)) { 534 pages++; 535 spin_lock(&init_mm.page_table_lock); 536 set_pte((pte_t *)pud, 537 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); 538 spin_unlock(&init_mm.page_table_lock); 539 last_map_addr = (addr & PUD_MASK) + PUD_SIZE; 540 continue; 541 } 542 543 pmd = alloc_low_page(&pmd_phys); 544 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, 545 prot); 546 unmap_low_page(pmd); 547 548 spin_lock(&init_mm.page_table_lock); 549 pud_populate(&init_mm, pud, __va(pmd_phys)); 550 spin_unlock(&init_mm.page_table_lock); 551 } 552 __flush_tlb_all(); 553 554 update_page_count(PG_LEVEL_1G, pages); 555 556 return last_map_addr; 557} 558 559unsigned long __meminit 560kernel_physical_mapping_init(unsigned long start, 561 unsigned long end, 562 unsigned long page_size_mask) 563{ 564 bool pgd_changed = false; 565 unsigned long next, last_map_addr = end; 566 unsigned long addr; 567 568 start = (unsigned long)__va(start); 569 end = (unsigned long)__va(end); 570 addr = start; 571 572 for (; start < end; start = next) { 573 pgd_t *pgd = pgd_offset_k(start); 574 unsigned long pud_phys; 575 pud_t *pud; 576 577 next = (start + PGDIR_SIZE) & PGDIR_MASK; 578 if (next > end) 579 next = end; 580 581 if (pgd_val(*pgd)) { 582 pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); 583 last_map_addr = phys_pud_init(pud, __pa(start), 584 __pa(end), page_size_mask); 585 unmap_low_page(pud); 586 continue; 587 } 588 589 pud = alloc_low_page(&pud_phys); 590 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next), 591 page_size_mask); 592 unmap_low_page(pud); 593 594 spin_lock(&init_mm.page_table_lock); 595 pgd_populate(&init_mm, pgd, __va(pud_phys)); 596 spin_unlock(&init_mm.page_table_lock); 597 pgd_changed = true; 598 } 599 600 if (pgd_changed) 601 sync_global_pgds(addr, end); 602 603 __flush_tlb_all(); 604 605 return last_map_addr; 606} 607 608#ifndef CONFIG_NUMA 609void __init initmem_init(void) 610{ 611 memblock_x86_register_active_regions(0, 0, max_pfn); 612} 613#endif 614 615void __init paging_init(void) 616{ 617 unsigned long max_zone_pfns[MAX_NR_ZONES]; 618 619 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 620#ifdef CONFIG_ZONE_DMA 621 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN; 622#endif 623 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN; 624 max_zone_pfns[ZONE_NORMAL] = max_pfn; 625 626 sparse_memory_present_with_active_regions(MAX_NUMNODES); 627 sparse_init(); 628 629 /* 630 * clear the default setting with node 0 631 * note: don't use nodes_clear here, that is really clearing when 632 * numa support is not compiled in, and later node_set_state 633 * will not set it back. 634 */ 635 node_clear_state(0, N_NORMAL_MEMORY); 636 637 free_area_init_nodes(max_zone_pfns); 638} 639 640/* 641 * Memory hotplug specific functions 642 */ 643#ifdef CONFIG_MEMORY_HOTPLUG 644/* 645 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need 646 * updating. 647 */ 648static void update_end_of_memory_vars(u64 start, u64 size) 649{ 650 unsigned long end_pfn = PFN_UP(start + size); 651 652 if (end_pfn > max_pfn) { 653 max_pfn = end_pfn; 654 max_low_pfn = end_pfn; 655 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; 656 } 657} 658 659/* 660 * Memory is added always to NORMAL zone. This means you will never get 661 * additional DMA/DMA32 memory. 662 */ 663int arch_add_memory(int nid, u64 start, u64 size) 664{ 665 struct pglist_data *pgdat = NODE_DATA(nid); 666 struct zone *zone = pgdat->node_zones + ZONE_NORMAL; 667 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT; 668 unsigned long nr_pages = size >> PAGE_SHIFT; 669 int ret; 670 671 last_mapped_pfn = init_memory_mapping(start, start + size); 672 if (last_mapped_pfn > max_pfn_mapped) 673 max_pfn_mapped = last_mapped_pfn; 674 675 ret = __add_pages(nid, zone, start_pfn, nr_pages); 676 WARN_ON_ONCE(ret); 677 678 /* update max_pfn, max_low_pfn and high_memory */ 679 update_end_of_memory_vars(start, size); 680 681 return ret; 682} 683EXPORT_SYMBOL_GPL(arch_add_memory); 684 685#endif /* CONFIG_MEMORY_HOTPLUG */ 686 687static struct kcore_list kcore_vsyscall; 688 689void __init mem_init(void) 690{ 691 long codesize, reservedpages, datasize, initsize; 692 unsigned long absent_pages; 693 694 pci_iommu_alloc(); 695 696 /* clear_bss() already clear the empty_zero_page */ 697 698 reservedpages = 0; 699 700 /* this will put all low memory onto the freelists */ 701#ifdef CONFIG_NUMA 702 totalram_pages = numa_free_all_bootmem(); 703#else 704 totalram_pages = free_all_bootmem(); 705#endif 706 707 absent_pages = absent_pages_in_range(0, max_pfn); 708 reservedpages = max_pfn - totalram_pages - absent_pages; 709 after_bootmem = 1; 710 711 codesize = (unsigned long) &_etext - (unsigned long) &_text; 712 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 713 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 714 715 /* Register memory areas for /proc/kcore */ 716 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, 717 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER); 718 719 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, " 720 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n", 721 nr_free_pages() << (PAGE_SHIFT-10), 722 max_pfn << (PAGE_SHIFT-10), 723 codesize >> 10, 724 absent_pages << (PAGE_SHIFT-10), 725 reservedpages << (PAGE_SHIFT-10), 726 datasize >> 10, 727 initsize >> 10); 728} 729 730#ifdef CONFIG_DEBUG_RODATA 731const int rodata_test_data = 0xC3; 732EXPORT_SYMBOL_GPL(rodata_test_data); 733 734int kernel_set_to_readonly; 735 736void set_kernel_text_rw(void) 737{ 738 unsigned long start = PFN_ALIGN(_text); 739 unsigned long end = PFN_ALIGN(__stop___ex_table); 740 741 if (!kernel_set_to_readonly) 742 return; 743 744 pr_debug("Set kernel text: %lx - %lx for read write\n", 745 start, end); 746 747 /* 748 * Make the kernel identity mapping for text RW. Kernel text 749 * mapping will always be RO. Refer to the comment in 750 * static_protections() in pageattr.c 751 */ 752 set_memory_rw(start, (end - start) >> PAGE_SHIFT); 753} 754 755void set_kernel_text_ro(void) 756{ 757 unsigned long start = PFN_ALIGN(_text); 758 unsigned long end = PFN_ALIGN(__stop___ex_table); 759 760 if (!kernel_set_to_readonly) 761 return; 762 763 pr_debug("Set kernel text: %lx - %lx for read only\n", 764 start, end); 765 766 /* 767 * Set the kernel identity mapping for text RO. 768 */ 769 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 770} 771 772void mark_rodata_ro(void) 773{ 774 unsigned long start = PFN_ALIGN(_text); 775 unsigned long rodata_start = 776 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; 777 unsigned long end = (unsigned long) &__end_rodata_hpage_align; 778 unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table); 779 unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata); 780 unsigned long data_start = (unsigned long) &_sdata; 781 782 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 783 (end - start) >> 10); 784 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 785 786 kernel_set_to_readonly = 1; 787 788 /* 789 * The rodata section (but not the kernel text!) should also be 790 * not-executable. 791 */ 792 set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); 793 794 rodata_test(); 795 796#ifdef CONFIG_CPA_DEBUG 797 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end); 798 set_memory_rw(start, (end-start) >> PAGE_SHIFT); 799 800 printk(KERN_INFO "Testing CPA: again\n"); 801 set_memory_ro(start, (end-start) >> PAGE_SHIFT); 802#endif 803 804 free_init_pages("unused kernel memory", 805 (unsigned long) page_address(virt_to_page(text_end)), 806 (unsigned long) 807 page_address(virt_to_page(rodata_start))); 808 free_init_pages("unused kernel memory", 809 (unsigned long) page_address(virt_to_page(rodata_end)), 810 (unsigned long) page_address(virt_to_page(data_start))); 811} 812 813#endif 814 815int kern_addr_valid(unsigned long addr) 816{ 817 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; 818 pgd_t *pgd; 819 pud_t *pud; 820 pmd_t *pmd; 821 pte_t *pte; 822 823 if (above != 0 && above != -1UL) 824 return 0; 825 826 pgd = pgd_offset_k(addr); 827 if (pgd_none(*pgd)) 828 return 0; 829 830 pud = pud_offset(pgd, addr); 831 if (pud_none(*pud)) 832 return 0; 833 834 pmd = pmd_offset(pud, addr); 835 if (pmd_none(*pmd)) 836 return 0; 837 838 if (pmd_large(*pmd)) 839 return pfn_valid(pmd_pfn(*pmd)); 840 841 pte = pte_offset_kernel(pmd, addr); 842 if (pte_none(*pte)) 843 return 0; 844 845 return pfn_valid(pte_pfn(*pte)); 846} 847 848/* 849 * A pseudo VMA to allow ptrace access for the vsyscall page. This only 850 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does 851 * not need special handling anymore: 852 */ 853static struct vm_area_struct gate_vma = { 854 .vm_start = VSYSCALL_START, 855 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE), 856 .vm_page_prot = PAGE_READONLY_EXEC, 857 .vm_flags = VM_READ | VM_EXEC 858}; 859 860struct vm_area_struct *get_gate_vma(struct mm_struct *mm) 861{ 862#ifdef CONFIG_IA32_EMULATION 863 if (!mm || mm->context.ia32_compat) 864 return NULL; 865#endif 866 return &gate_vma; 867} 868 869int in_gate_area(struct mm_struct *mm, unsigned long addr) 870{ 871 struct vm_area_struct *vma = get_gate_vma(mm); 872 873 if (!vma) 874 return 0; 875 876 return (addr >= vma->vm_start) && (addr < vma->vm_end); 877} 878 879/* 880 * Use this when you have no reliable mm, typically from interrupt 881 * context. It is less reliable than using a task's mm and may give 882 * false positives. 883 */ 884int in_gate_area_no_mm(unsigned long addr) 885{ 886 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END); 887} 888 889const char *arch_vma_name(struct vm_area_struct *vma) 890{ 891 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) 892 return "[vdso]"; 893 if (vma == &gate_vma) 894 return "[vsyscall]"; 895 return NULL; 896} 897 898#ifdef CONFIG_X86_UV 899unsigned long memory_block_size_bytes(void) 900{ 901 if (is_uv_system()) { 902 printk(KERN_INFO "UV: memory block size 2GB\n"); 903 return 2UL * 1024 * 1024 * 1024; 904 } 905 return MIN_MEMORY_BLOCK_SIZE; 906} 907#endif 908 909#ifdef CONFIG_SPARSEMEM_VMEMMAP 910/* 911 * Initialise the sparsemem vmemmap using huge-pages at the PMD level. 912 */ 913static long __meminitdata addr_start, addr_end; 914static void __meminitdata *p_start, *p_end; 915static int __meminitdata node_start; 916 917int __meminit 918vmemmap_populate(struct page *start_page, unsigned long size, int node) 919{ 920 unsigned long addr = (unsigned long)start_page; 921 unsigned long end = (unsigned long)(start_page + size); 922 unsigned long next; 923 pgd_t *pgd; 924 pud_t *pud; 925 pmd_t *pmd; 926 927 for (; addr < end; addr = next) { 928 void *p = NULL; 929 930 pgd = vmemmap_pgd_populate(addr, node); 931 if (!pgd) 932 return -ENOMEM; 933 934 pud = vmemmap_pud_populate(pgd, addr, node); 935 if (!pud) 936 return -ENOMEM; 937 938 if (!cpu_has_pse) { 939 next = (addr + PAGE_SIZE) & PAGE_MASK; 940 pmd = vmemmap_pmd_populate(pud, addr, node); 941 942 if (!pmd) 943 return -ENOMEM; 944 945 p = vmemmap_pte_populate(pmd, addr, node); 946 947 if (!p) 948 return -ENOMEM; 949 950 addr_end = addr + PAGE_SIZE; 951 p_end = p + PAGE_SIZE; 952 } else { 953 next = pmd_addr_end(addr, end); 954 955 pmd = pmd_offset(pud, addr); 956 if (pmd_none(*pmd)) { 957 pte_t entry; 958 959 p = vmemmap_alloc_block_buf(PMD_SIZE, node); 960 if (!p) 961 return -ENOMEM; 962 963 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, 964 PAGE_KERNEL_LARGE); 965 set_pmd(pmd, __pmd(pte_val(entry))); 966 967 /* check to see if we have contiguous blocks */ 968 if (p_end != p || node_start != node) { 969 if (p_start) 970 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 971 addr_start, addr_end-1, p_start, p_end-1, node_start); 972 addr_start = addr; 973 node_start = node; 974 p_start = p; 975 } 976 977 addr_end = addr + PMD_SIZE; 978 p_end = p + PMD_SIZE; 979 } else 980 vmemmap_verify((pte_t *)pmd, node, addr, next); 981 } 982 983 } 984 sync_global_pgds((unsigned long)start_page, end); 985 return 0; 986} 987 988void __meminit vmemmap_populate_print_last(void) 989{ 990 if (p_start) { 991 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 992 addr_start, addr_end-1, p_start, p_end-1, node_start); 993 p_start = NULL; 994 p_end = NULL; 995 node_start = 0; 996 } 997} 998#endif 999