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/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 <asm/uv/uv.h> 55 #include <asm/setup.h> 56 57 static int __init parse_direct_gbpages_off(char *arg) 58 { 59 direct_gbpages = 0; 60 return 0; 61 } 62 early_param("nogbpages", parse_direct_gbpages_off); 63 64 static int __init parse_direct_gbpages_on(char *arg) 65 { 66 direct_gbpages = 1; 67 return 0; 68 } 69 early_param("gbpages", parse_direct_gbpages_on); 70 71 /* 72 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the 73 * physical space so we can cache the place of the first one and move 74 * around without checking the pgd every time. 75 */ 76 77 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP; 78 EXPORT_SYMBOL_GPL(__supported_pte_mask); 79 80 int force_personality32; 81 82 /* 83 * noexec32=on|off 84 * Control non executable heap for 32bit processes. 85 * To control the stack too use noexec=off 86 * 87 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default) 88 * off PROT_READ implies PROT_EXEC 89 */ 90 static int __init nonx32_setup(char *str) 91 { 92 if (!strcmp(str, "on")) 93 force_personality32 &= ~READ_IMPLIES_EXEC; 94 else if (!strcmp(str, "off")) 95 force_personality32 |= READ_IMPLIES_EXEC; 96 return 1; 97 } 98 __setup("noexec32=", nonx32_setup); 99 100 /* 101 * When memory was added/removed make sure all the processes MM have 102 * suitable PGD entries in the local PGD level page. 103 */ 104 void sync_global_pgds(unsigned long start, unsigned long end) 105 { 106 unsigned long address; 107 108 for (address = start; address <= end; address += PGDIR_SIZE) { 109 const pgd_t *pgd_ref = pgd_offset_k(address); 110 struct page *page; 111 112 if (pgd_none(*pgd_ref)) 113 continue; 114 115 spin_lock(&pgd_lock); 116 list_for_each_entry(page, &pgd_list, lru) { 117 pgd_t *pgd; 118 spinlock_t *pgt_lock; 119 120 pgd = (pgd_t *)page_address(page) + pgd_index(address); 121 /* the pgt_lock only for Xen */ 122 pgt_lock = &pgd_page_get_mm(page)->page_table_lock; 123 spin_lock(pgt_lock); 124 125 if (pgd_none(*pgd)) 126 set_pgd(pgd, *pgd_ref); 127 else 128 BUG_ON(pgd_page_vaddr(*pgd) 129 != pgd_page_vaddr(*pgd_ref)); 130 131 spin_unlock(pgt_lock); 132 } 133 spin_unlock(&pgd_lock); 134 } 135 } 136 137 /* 138 * NOTE: This function is marked __ref because it calls __init function 139 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. 140 */ 141 static __ref void *spp_getpage(void) 142 { 143 void *ptr; 144 145 if (after_bootmem) 146 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 147 else 148 ptr = alloc_bootmem_pages(PAGE_SIZE); 149 150 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) { 151 panic("set_pte_phys: cannot allocate page data %s\n", 152 after_bootmem ? "after bootmem" : ""); 153 } 154 155 pr_debug("spp_getpage %p\n", ptr); 156 157 return ptr; 158 } 159 160 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr) 161 { 162 if (pgd_none(*pgd)) { 163 pud_t *pud = (pud_t *)spp_getpage(); 164 pgd_populate(&init_mm, pgd, pud); 165 if (pud != pud_offset(pgd, 0)) 166 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n", 167 pud, pud_offset(pgd, 0)); 168 } 169 return pud_offset(pgd, vaddr); 170 } 171 172 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr) 173 { 174 if (pud_none(*pud)) { 175 pmd_t *pmd = (pmd_t *) spp_getpage(); 176 pud_populate(&init_mm, pud, pmd); 177 if (pmd != pmd_offset(pud, 0)) 178 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n", 179 pmd, pmd_offset(pud, 0)); 180 } 181 return pmd_offset(pud, vaddr); 182 } 183 184 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr) 185 { 186 if (pmd_none(*pmd)) { 187 pte_t *pte = (pte_t *) spp_getpage(); 188 pmd_populate_kernel(&init_mm, pmd, pte); 189 if (pte != pte_offset_kernel(pmd, 0)) 190 printk(KERN_ERR "PAGETABLE BUG #02!\n"); 191 } 192 return pte_offset_kernel(pmd, vaddr); 193 } 194 195 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte) 196 { 197 pud_t *pud; 198 pmd_t *pmd; 199 pte_t *pte; 200 201 pud = pud_page + pud_index(vaddr); 202 pmd = fill_pmd(pud, vaddr); 203 pte = fill_pte(pmd, vaddr); 204 205 set_pte(pte, new_pte); 206 207 /* 208 * It's enough to flush this one mapping. 209 * (PGE mappings get flushed as well) 210 */ 211 __flush_tlb_one(vaddr); 212 } 213 214 void set_pte_vaddr(unsigned long vaddr, pte_t pteval) 215 { 216 pgd_t *pgd; 217 pud_t *pud_page; 218 219 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval)); 220 221 pgd = pgd_offset_k(vaddr); 222 if (pgd_none(*pgd)) { 223 printk(KERN_ERR 224 "PGD FIXMAP MISSING, it should be setup in head.S!\n"); 225 return; 226 } 227 pud_page = (pud_t*)pgd_page_vaddr(*pgd); 228 set_pte_vaddr_pud(pud_page, vaddr, pteval); 229 } 230 231 pmd_t * __init populate_extra_pmd(unsigned long vaddr) 232 { 233 pgd_t *pgd; 234 pud_t *pud; 235 236 pgd = pgd_offset_k(vaddr); 237 pud = fill_pud(pgd, vaddr); 238 return fill_pmd(pud, vaddr); 239 } 240 241 pte_t * __init populate_extra_pte(unsigned long vaddr) 242 { 243 pmd_t *pmd; 244 245 pmd = populate_extra_pmd(vaddr); 246 return fill_pte(pmd, vaddr); 247 } 248 249 /* 250 * Create large page table mappings for a range of physical addresses. 251 */ 252 static void __init __init_extra_mapping(unsigned long phys, unsigned long size, 253 pgprot_t prot) 254 { 255 pgd_t *pgd; 256 pud_t *pud; 257 pmd_t *pmd; 258 259 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK)); 260 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) { 261 pgd = pgd_offset_k((unsigned long)__va(phys)); 262 if (pgd_none(*pgd)) { 263 pud = (pud_t *) spp_getpage(); 264 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE | 265 _PAGE_USER)); 266 } 267 pud = pud_offset(pgd, (unsigned long)__va(phys)); 268 if (pud_none(*pud)) { 269 pmd = (pmd_t *) spp_getpage(); 270 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | 271 _PAGE_USER)); 272 } 273 pmd = pmd_offset(pud, phys); 274 BUG_ON(!pmd_none(*pmd)); 275 set_pmd(pmd, __pmd(phys | pgprot_val(prot))); 276 } 277 } 278 279 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size) 280 { 281 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE); 282 } 283 284 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size) 285 { 286 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE); 287 } 288 289 /* 290 * The head.S code sets up the kernel high mapping: 291 * 292 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text) 293 * 294 * phys_addr holds the negative offset to the kernel, which is added 295 * to the compile time generated pmds. This results in invalid pmds up 296 * to the point where we hit the physaddr 0 mapping. 297 * 298 * We limit the mappings to the region from _text to _brk_end. _brk_end 299 * is rounded up to the 2MB boundary. This catches the invalid pmds as 300 * well, as they are located before _text: 301 */ 302 void __init cleanup_highmap(void) 303 { 304 unsigned long vaddr = __START_KERNEL_map; 305 unsigned long vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT); 306 unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1; 307 pmd_t *pmd = level2_kernel_pgt; 308 309 for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) { 310 if (pmd_none(*pmd)) 311 continue; 312 if (vaddr < (unsigned long) _text || vaddr > end) 313 set_pmd(pmd, __pmd(0)); 314 } 315 } 316 317 static __ref void *alloc_low_page(unsigned long *phys) 318 { 319 unsigned long pfn = pgt_buf_end++; 320 void *adr; 321 322 if (after_bootmem) { 323 adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 324 *phys = __pa(adr); 325 326 return adr; 327 } 328 329 if (pfn >= pgt_buf_top) 330 panic("alloc_low_page: ran out of memory"); 331 332 adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE); 333 clear_page(adr); 334 *phys = pfn * PAGE_SIZE; 335 return adr; 336 } 337 338 static __ref void *map_low_page(void *virt) 339 { 340 void *adr; 341 unsigned long phys, left; 342 343 if (after_bootmem) 344 return virt; 345 346 phys = __pa(virt); 347 left = phys & (PAGE_SIZE - 1); 348 adr = early_memremap(phys & PAGE_MASK, PAGE_SIZE); 349 adr = (void *)(((unsigned long)adr) | left); 350 351 return adr; 352 } 353 354 static __ref void unmap_low_page(void *adr) 355 { 356 if (after_bootmem) 357 return; 358 359 early_iounmap((void *)((unsigned long)adr & PAGE_MASK), PAGE_SIZE); 360 } 361 362 static unsigned long __meminit 363 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, 364 pgprot_t prot) 365 { 366 unsigned pages = 0; 367 unsigned long last_map_addr = end; 368 int i; 369 370 pte_t *pte = pte_page + pte_index(addr); 371 372 for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { 373 374 if (addr >= end) { 375 if (!after_bootmem) { 376 for(; i < PTRS_PER_PTE; i++, pte++) 377 set_pte(pte, __pte(0)); 378 } 379 break; 380 } 381 382 /* 383 * We will re-use the existing mapping. 384 * Xen for example has some special requirements, like mapping 385 * pagetable pages as RO. So assume someone who pre-setup 386 * these mappings are more intelligent. 387 */ 388 if (pte_val(*pte)) { 389 if (!after_bootmem) 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 } 406 407 static unsigned long __meminit 408 phys_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, next; 412 unsigned long last_map_addr = end; 413 414 int i = pmd_index(address); 415 416 for (; i < PTRS_PER_PMD; i++, address = next) { 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 next = (address & PMD_MASK) + PMD_SIZE; 431 432 if (pmd_val(*pmd)) { 433 if (!pmd_large(*pmd)) { 434 spin_lock(&init_mm.page_table_lock); 435 pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); 436 last_map_addr = phys_pte_init(pte, address, 437 end, prot); 438 unmap_low_page(pte); 439 spin_unlock(&init_mm.page_table_lock); 440 continue; 441 } 442 /* 443 * If we are ok with PG_LEVEL_2M mapping, then we will 444 * use the existing mapping, 445 * 446 * Otherwise, we will split the large page mapping but 447 * use the same existing protection bits except for 448 * large page, so that we don't violate Intel's TLB 449 * Application note (317080) which says, while changing 450 * the page sizes, new and old translations should 451 * not differ with respect to page frame and 452 * attributes. 453 */ 454 if (page_size_mask & (1 << PG_LEVEL_2M)) { 455 if (!after_bootmem) 456 pages++; 457 last_map_addr = next; 458 continue; 459 } 460 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); 461 } 462 463 if (page_size_mask & (1<<PG_LEVEL_2M)) { 464 pages++; 465 spin_lock(&init_mm.page_table_lock); 466 set_pte((pte_t *)pmd, 467 pfn_pte(address >> PAGE_SHIFT, 468 __pgprot(pgprot_val(prot) | _PAGE_PSE))); 469 spin_unlock(&init_mm.page_table_lock); 470 last_map_addr = next; 471 continue; 472 } 473 474 pte = alloc_low_page(&pte_phys); 475 last_map_addr = phys_pte_init(pte, address, end, new_prot); 476 unmap_low_page(pte); 477 478 spin_lock(&init_mm.page_table_lock); 479 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); 480 spin_unlock(&init_mm.page_table_lock); 481 } 482 update_page_count(PG_LEVEL_2M, pages); 483 return last_map_addr; 484 } 485 486 static unsigned long __meminit 487 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 488 unsigned long page_size_mask) 489 { 490 unsigned long pages = 0, next; 491 unsigned long last_map_addr = end; 492 int i = pud_index(addr); 493 494 for (; i < PTRS_PER_PUD; i++, addr = next) { 495 unsigned long pmd_phys; 496 pud_t *pud = pud_page + pud_index(addr); 497 pmd_t *pmd; 498 pgprot_t prot = PAGE_KERNEL; 499 500 if (addr >= end) 501 break; 502 503 next = (addr & PUD_MASK) + PUD_SIZE; 504 505 if (!after_bootmem && !e820_any_mapped(addr, next, 0)) { 506 set_pud(pud, __pud(0)); 507 continue; 508 } 509 510 if (pud_val(*pud)) { 511 if (!pud_large(*pud)) { 512 pmd = map_low_page(pmd_offset(pud, 0)); 513 last_map_addr = phys_pmd_init(pmd, addr, end, 514 page_size_mask, prot); 515 unmap_low_page(pmd); 516 __flush_tlb_all(); 517 continue; 518 } 519 /* 520 * If we are ok with PG_LEVEL_1G mapping, then we will 521 * use the existing mapping. 522 * 523 * Otherwise, we will split the gbpage mapping but use 524 * the same existing protection bits except for large 525 * page, so that we don't violate Intel's TLB 526 * Application note (317080) which says, while changing 527 * the page sizes, new and old translations should 528 * not differ with respect to page frame and 529 * attributes. 530 */ 531 if (page_size_mask & (1 << PG_LEVEL_1G)) { 532 if (!after_bootmem) 533 pages++; 534 last_map_addr = next; 535 continue; 536 } 537 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); 538 } 539 540 if (page_size_mask & (1<<PG_LEVEL_1G)) { 541 pages++; 542 spin_lock(&init_mm.page_table_lock); 543 set_pte((pte_t *)pud, 544 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); 545 spin_unlock(&init_mm.page_table_lock); 546 last_map_addr = next; 547 continue; 548 } 549 550 pmd = alloc_low_page(&pmd_phys); 551 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, 552 prot); 553 unmap_low_page(pmd); 554 555 spin_lock(&init_mm.page_table_lock); 556 pud_populate(&init_mm, pud, __va(pmd_phys)); 557 spin_unlock(&init_mm.page_table_lock); 558 } 559 __flush_tlb_all(); 560 561 update_page_count(PG_LEVEL_1G, pages); 562 563 return last_map_addr; 564 } 565 566 unsigned long __meminit 567 kernel_physical_mapping_init(unsigned long start, 568 unsigned long end, 569 unsigned long page_size_mask) 570 { 571 bool pgd_changed = false; 572 unsigned long next, last_map_addr = end; 573 unsigned long addr; 574 575 start = (unsigned long)__va(start); 576 end = (unsigned long)__va(end); 577 addr = start; 578 579 for (; start < end; start = next) { 580 pgd_t *pgd = pgd_offset_k(start); 581 unsigned long pud_phys; 582 pud_t *pud; 583 584 next = (start + PGDIR_SIZE) & PGDIR_MASK; 585 if (next > end) 586 next = end; 587 588 if (pgd_val(*pgd)) { 589 pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); 590 last_map_addr = phys_pud_init(pud, __pa(start), 591 __pa(end), page_size_mask); 592 unmap_low_page(pud); 593 continue; 594 } 595 596 pud = alloc_low_page(&pud_phys); 597 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next), 598 page_size_mask); 599 unmap_low_page(pud); 600 601 spin_lock(&init_mm.page_table_lock); 602 pgd_populate(&init_mm, pgd, __va(pud_phys)); 603 spin_unlock(&init_mm.page_table_lock); 604 pgd_changed = true; 605 } 606 607 if (pgd_changed) 608 sync_global_pgds(addr, end); 609 610 __flush_tlb_all(); 611 612 return last_map_addr; 613 } 614 615 #ifndef CONFIG_NUMA 616 void __init initmem_init(void) 617 { 618 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0); 619 } 620 #endif 621 622 void __init paging_init(void) 623 { 624 sparse_memory_present_with_active_regions(MAX_NUMNODES); 625 sparse_init(); 626 627 /* 628 * clear the default setting with node 0 629 * note: don't use nodes_clear here, that is really clearing when 630 * numa support is not compiled in, and later node_set_state 631 * will not set it back. 632 */ 633 node_clear_state(0, N_NORMAL_MEMORY); 634 635 zone_sizes_init(); 636 } 637 638 /* 639 * Memory hotplug specific functions 640 */ 641 #ifdef CONFIG_MEMORY_HOTPLUG 642 /* 643 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need 644 * updating. 645 */ 646 static void update_end_of_memory_vars(u64 start, u64 size) 647 { 648 unsigned long end_pfn = PFN_UP(start + size); 649 650 if (end_pfn > max_pfn) { 651 max_pfn = end_pfn; 652 max_low_pfn = end_pfn; 653 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; 654 } 655 } 656 657 /* 658 * Memory is added always to NORMAL zone. This means you will never get 659 * additional DMA/DMA32 memory. 660 */ 661 int arch_add_memory(int nid, u64 start, u64 size) 662 { 663 struct pglist_data *pgdat = NODE_DATA(nid); 664 struct zone *zone = pgdat->node_zones + ZONE_NORMAL; 665 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT; 666 unsigned long nr_pages = size >> PAGE_SHIFT; 667 int ret; 668 669 last_mapped_pfn = init_memory_mapping(start, start + size); 670 if (last_mapped_pfn > max_pfn_mapped) 671 max_pfn_mapped = last_mapped_pfn; 672 673 ret = __add_pages(nid, zone, start_pfn, nr_pages); 674 WARN_ON_ONCE(ret); 675 676 /* update max_pfn, max_low_pfn and high_memory */ 677 update_end_of_memory_vars(start, size); 678 679 return ret; 680 } 681 EXPORT_SYMBOL_GPL(arch_add_memory); 682 683 #endif /* CONFIG_MEMORY_HOTPLUG */ 684 685 static struct kcore_list kcore_vsyscall; 686 687 void __init mem_init(void) 688 { 689 long codesize, reservedpages, datasize, initsize; 690 unsigned long absent_pages; 691 692 pci_iommu_alloc(); 693 694 /* clear_bss() already clear the empty_zero_page */ 695 696 reservedpages = 0; 697 698 /* this will put all low memory onto the freelists */ 699 #ifdef CONFIG_NUMA 700 totalram_pages = numa_free_all_bootmem(); 701 #else 702 totalram_pages = free_all_bootmem(); 703 #endif 704 705 absent_pages = absent_pages_in_range(0, max_pfn); 706 reservedpages = max_pfn - totalram_pages - absent_pages; 707 after_bootmem = 1; 708 709 codesize = (unsigned long) &_etext - (unsigned long) &_text; 710 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 711 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 712 713 /* Register memory areas for /proc/kcore */ 714 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, 715 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER); 716 717 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, " 718 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n", 719 nr_free_pages() << (PAGE_SHIFT-10), 720 max_pfn << (PAGE_SHIFT-10), 721 codesize >> 10, 722 absent_pages << (PAGE_SHIFT-10), 723 reservedpages << (PAGE_SHIFT-10), 724 datasize >> 10, 725 initsize >> 10); 726 } 727 728 #ifdef CONFIG_DEBUG_RODATA 729 const int rodata_test_data = 0xC3; 730 EXPORT_SYMBOL_GPL(rodata_test_data); 731 732 int kernel_set_to_readonly; 733 734 void set_kernel_text_rw(void) 735 { 736 unsigned long start = PFN_ALIGN(_text); 737 unsigned long end = PFN_ALIGN(__stop___ex_table); 738 739 if (!kernel_set_to_readonly) 740 return; 741 742 pr_debug("Set kernel text: %lx - %lx for read write\n", 743 start, end); 744 745 /* 746 * Make the kernel identity mapping for text RW. Kernel text 747 * mapping will always be RO. Refer to the comment in 748 * static_protections() in pageattr.c 749 */ 750 set_memory_rw(start, (end - start) >> PAGE_SHIFT); 751 } 752 753 void set_kernel_text_ro(void) 754 { 755 unsigned long start = PFN_ALIGN(_text); 756 unsigned long end = PFN_ALIGN(__stop___ex_table); 757 758 if (!kernel_set_to_readonly) 759 return; 760 761 pr_debug("Set kernel text: %lx - %lx for read only\n", 762 start, end); 763 764 /* 765 * Set the kernel identity mapping for text RO. 766 */ 767 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 768 } 769 770 void mark_rodata_ro(void) 771 { 772 unsigned long start = PFN_ALIGN(_text); 773 unsigned long rodata_start = 774 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; 775 unsigned long end = (unsigned long) &__end_rodata_hpage_align; 776 unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table); 777 unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata); 778 unsigned long data_start = (unsigned long) &_sdata; 779 780 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 781 (end - start) >> 10); 782 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 783 784 kernel_set_to_readonly = 1; 785 786 /* 787 * The rodata section (but not the kernel text!) should also be 788 * not-executable. 789 */ 790 set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); 791 792 rodata_test(); 793 794 #ifdef CONFIG_CPA_DEBUG 795 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end); 796 set_memory_rw(start, (end-start) >> PAGE_SHIFT); 797 798 printk(KERN_INFO "Testing CPA: again\n"); 799 set_memory_ro(start, (end-start) >> PAGE_SHIFT); 800 #endif 801 802 free_init_pages("unused kernel memory", 803 (unsigned long) page_address(virt_to_page(text_end)), 804 (unsigned long) 805 page_address(virt_to_page(rodata_start))); 806 free_init_pages("unused kernel memory", 807 (unsigned long) page_address(virt_to_page(rodata_end)), 808 (unsigned long) page_address(virt_to_page(data_start))); 809 } 810 811 #endif 812 813 int kern_addr_valid(unsigned long addr) 814 { 815 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; 816 pgd_t *pgd; 817 pud_t *pud; 818 pmd_t *pmd; 819 pte_t *pte; 820 821 if (above != 0 && above != -1UL) 822 return 0; 823 824 pgd = pgd_offset_k(addr); 825 if (pgd_none(*pgd)) 826 return 0; 827 828 pud = pud_offset(pgd, addr); 829 if (pud_none(*pud)) 830 return 0; 831 832 pmd = pmd_offset(pud, addr); 833 if (pmd_none(*pmd)) 834 return 0; 835 836 if (pmd_large(*pmd)) 837 return pfn_valid(pmd_pfn(*pmd)); 838 839 pte = pte_offset_kernel(pmd, addr); 840 if (pte_none(*pte)) 841 return 0; 842 843 return pfn_valid(pte_pfn(*pte)); 844 } 845 846 /* 847 * A pseudo VMA to allow ptrace access for the vsyscall page. This only 848 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does 849 * not need special handling anymore: 850 */ 851 static struct vm_area_struct gate_vma = { 852 .vm_start = VSYSCALL_START, 853 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE), 854 .vm_page_prot = PAGE_READONLY_EXEC, 855 .vm_flags = VM_READ | VM_EXEC 856 }; 857 858 struct vm_area_struct *get_gate_vma(struct mm_struct *mm) 859 { 860 #ifdef CONFIG_IA32_EMULATION 861 if (!mm || mm->context.ia32_compat) 862 return NULL; 863 #endif 864 return &gate_vma; 865 } 866 867 int in_gate_area(struct mm_struct *mm, unsigned long addr) 868 { 869 struct vm_area_struct *vma = get_gate_vma(mm); 870 871 if (!vma) 872 return 0; 873 874 return (addr >= vma->vm_start) && (addr < vma->vm_end); 875 } 876 877 /* 878 * Use this when you have no reliable mm, typically from interrupt 879 * context. It is less reliable than using a task's mm and may give 880 * false positives. 881 */ 882 int in_gate_area_no_mm(unsigned long addr) 883 { 884 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END); 885 } 886 887 const char *arch_vma_name(struct vm_area_struct *vma) 888 { 889 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) 890 return "[vdso]"; 891 if (vma == &gate_vma) 892 return "[vsyscall]"; 893 return NULL; 894 } 895 896 #ifdef CONFIG_X86_UV 897 unsigned long memory_block_size_bytes(void) 898 { 899 if (is_uv_system()) { 900 printk(KERN_INFO "UV: memory block size 2GB\n"); 901 return 2UL * 1024 * 1024 * 1024; 902 } 903 return MIN_MEMORY_BLOCK_SIZE; 904 } 905 #endif 906 907 #ifdef CONFIG_SPARSEMEM_VMEMMAP 908 /* 909 * Initialise the sparsemem vmemmap using huge-pages at the PMD level. 910 */ 911 static long __meminitdata addr_start, addr_end; 912 static void __meminitdata *p_start, *p_end; 913 static int __meminitdata node_start; 914 915 int __meminit 916 vmemmap_populate(struct page *start_page, unsigned long size, int node) 917 { 918 unsigned long addr = (unsigned long)start_page; 919 unsigned long end = (unsigned long)(start_page + size); 920 unsigned long next; 921 pgd_t *pgd; 922 pud_t *pud; 923 pmd_t *pmd; 924 925 for (; addr < end; addr = next) { 926 void *p = NULL; 927 928 pgd = vmemmap_pgd_populate(addr, node); 929 if (!pgd) 930 return -ENOMEM; 931 932 pud = vmemmap_pud_populate(pgd, addr, node); 933 if (!pud) 934 return -ENOMEM; 935 936 if (!cpu_has_pse) { 937 next = (addr + PAGE_SIZE) & PAGE_MASK; 938 pmd = vmemmap_pmd_populate(pud, addr, node); 939 940 if (!pmd) 941 return -ENOMEM; 942 943 p = vmemmap_pte_populate(pmd, addr, node); 944 945 if (!p) 946 return -ENOMEM; 947 948 addr_end = addr + PAGE_SIZE; 949 p_end = p + PAGE_SIZE; 950 } else { 951 next = pmd_addr_end(addr, end); 952 953 pmd = pmd_offset(pud, addr); 954 if (pmd_none(*pmd)) { 955 pte_t entry; 956 957 p = vmemmap_alloc_block_buf(PMD_SIZE, node); 958 if (!p) 959 return -ENOMEM; 960 961 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, 962 PAGE_KERNEL_LARGE); 963 set_pmd(pmd, __pmd(pte_val(entry))); 964 965 /* check to see if we have contiguous blocks */ 966 if (p_end != p || node_start != node) { 967 if (p_start) 968 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 969 addr_start, addr_end-1, p_start, p_end-1, node_start); 970 addr_start = addr; 971 node_start = node; 972 p_start = p; 973 } 974 975 addr_end = addr + PMD_SIZE; 976 p_end = p + PMD_SIZE; 977 } else 978 vmemmap_verify((pte_t *)pmd, node, addr, next); 979 } 980 981 } 982 sync_global_pgds((unsigned long)start_page, end); 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