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 58 static int __init parse_direct_gbpages_off(char *arg) 59 { 60 direct_gbpages = 0; 61 return 0; 62 } 63 early_param("nogbpages", parse_direct_gbpages_off); 64 65 static int __init parse_direct_gbpages_on(char *arg) 66 { 67 direct_gbpages = 1; 68 return 0; 69 } 70 early_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 78 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP; 79 EXPORT_SYMBOL_GPL(__supported_pte_mask); 80 81 int 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 */ 91 static 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 */ 105 void 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 */ 142 static __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 } 160 161 static 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 } 172 173 static 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 } 184 185 static 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 } 195 196 void 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 } 214 215 void 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 } 231 232 pmd_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 } 241 242 pte_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 */ 253 static 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 } 279 280 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size) 281 { 282 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE); 283 } 284 285 void __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 */ 303 void __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 } 317 318 static __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 } 338 339 static __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 } 354 355 static __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 } 362 363 static unsigned long __meminit 364 phys_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 } 406 407 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; 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 } 481 482 static unsigned long __meminit 483 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 484 unsigned long page_size_mask) 485 { 486 unsigned long pages = 0; 487 unsigned long last_map_addr = end; 488 int i = pud_index(addr); 489 490 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) { 491 unsigned long pmd_phys; 492 pud_t *pud = pud_page + pud_index(addr); 493 pmd_t *pmd; 494 pgprot_t prot = PAGE_KERNEL; 495 496 if (addr >= end) 497 break; 498 499 if (!after_bootmem && 500 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) { 501 set_pud(pud, __pud(0)); 502 continue; 503 } 504 505 if (pud_val(*pud)) { 506 if (!pud_large(*pud)) { 507 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 } 558 559 unsigned long __meminit 560 kernel_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 609 void __init initmem_init(void) 610 { 611 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0); 612 } 613 #endif 614 615 void __init paging_init(void) 616 { 617 sparse_memory_present_with_active_regions(MAX_NUMNODES); 618 sparse_init(); 619 620 /* 621 * clear the default setting with node 0 622 * note: don't use nodes_clear here, that is really clearing when 623 * numa support is not compiled in, and later node_set_state 624 * will not set it back. 625 */ 626 node_clear_state(0, N_NORMAL_MEMORY); 627 628 zone_sizes_init(); 629 } 630 631 /* 632 * Memory hotplug specific functions 633 */ 634 #ifdef CONFIG_MEMORY_HOTPLUG 635 /* 636 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need 637 * updating. 638 */ 639 static void update_end_of_memory_vars(u64 start, u64 size) 640 { 641 unsigned long end_pfn = PFN_UP(start + size); 642 643 if (end_pfn > max_pfn) { 644 max_pfn = end_pfn; 645 max_low_pfn = end_pfn; 646 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; 647 } 648 } 649 650 /* 651 * Memory is added always to NORMAL zone. This means you will never get 652 * additional DMA/DMA32 memory. 653 */ 654 int arch_add_memory(int nid, u64 start, u64 size) 655 { 656 struct pglist_data *pgdat = NODE_DATA(nid); 657 struct zone *zone = pgdat->node_zones + ZONE_NORMAL; 658 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT; 659 unsigned long nr_pages = size >> PAGE_SHIFT; 660 int ret; 661 662 last_mapped_pfn = init_memory_mapping(start, start + size); 663 if (last_mapped_pfn > max_pfn_mapped) 664 max_pfn_mapped = last_mapped_pfn; 665 666 ret = __add_pages(nid, zone, start_pfn, nr_pages); 667 WARN_ON_ONCE(ret); 668 669 /* update max_pfn, max_low_pfn and high_memory */ 670 update_end_of_memory_vars(start, size); 671 672 return ret; 673 } 674 EXPORT_SYMBOL_GPL(arch_add_memory); 675 676 #endif /* CONFIG_MEMORY_HOTPLUG */ 677 678 static struct kcore_list kcore_vsyscall; 679 680 void __init mem_init(void) 681 { 682 long codesize, reservedpages, datasize, initsize; 683 unsigned long absent_pages; 684 685 pci_iommu_alloc(); 686 687 /* clear_bss() already clear the empty_zero_page */ 688 689 reservedpages = 0; 690 691 /* this will put all low memory onto the freelists */ 692 #ifdef CONFIG_NUMA 693 totalram_pages = numa_free_all_bootmem(); 694 #else 695 totalram_pages = free_all_bootmem(); 696 #endif 697 698 absent_pages = absent_pages_in_range(0, max_pfn); 699 reservedpages = max_pfn - totalram_pages - absent_pages; 700 after_bootmem = 1; 701 702 codesize = (unsigned long) &_etext - (unsigned long) &_text; 703 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 704 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 705 706 /* Register memory areas for /proc/kcore */ 707 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, 708 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER); 709 710 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, " 711 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n", 712 nr_free_pages() << (PAGE_SHIFT-10), 713 max_pfn << (PAGE_SHIFT-10), 714 codesize >> 10, 715 absent_pages << (PAGE_SHIFT-10), 716 reservedpages << (PAGE_SHIFT-10), 717 datasize >> 10, 718 initsize >> 10); 719 } 720 721 #ifdef CONFIG_DEBUG_RODATA 722 const int rodata_test_data = 0xC3; 723 EXPORT_SYMBOL_GPL(rodata_test_data); 724 725 int kernel_set_to_readonly; 726 727 void set_kernel_text_rw(void) 728 { 729 unsigned long start = PFN_ALIGN(_text); 730 unsigned long end = PFN_ALIGN(__stop___ex_table); 731 732 if (!kernel_set_to_readonly) 733 return; 734 735 pr_debug("Set kernel text: %lx - %lx for read write\n", 736 start, end); 737 738 /* 739 * Make the kernel identity mapping for text RW. Kernel text 740 * mapping will always be RO. Refer to the comment in 741 * static_protections() in pageattr.c 742 */ 743 set_memory_rw(start, (end - start) >> PAGE_SHIFT); 744 } 745 746 void set_kernel_text_ro(void) 747 { 748 unsigned long start = PFN_ALIGN(_text); 749 unsigned long end = PFN_ALIGN(__stop___ex_table); 750 751 if (!kernel_set_to_readonly) 752 return; 753 754 pr_debug("Set kernel text: %lx - %lx for read only\n", 755 start, end); 756 757 /* 758 * Set the kernel identity mapping for text RO. 759 */ 760 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 761 } 762 763 void mark_rodata_ro(void) 764 { 765 unsigned long start = PFN_ALIGN(_text); 766 unsigned long rodata_start = 767 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; 768 unsigned long end = (unsigned long) &__end_rodata_hpage_align; 769 unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table); 770 unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata); 771 unsigned long data_start = (unsigned long) &_sdata; 772 773 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 774 (end - start) >> 10); 775 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 776 777 kernel_set_to_readonly = 1; 778 779 /* 780 * The rodata section (but not the kernel text!) should also be 781 * not-executable. 782 */ 783 set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); 784 785 rodata_test(); 786 787 #ifdef CONFIG_CPA_DEBUG 788 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end); 789 set_memory_rw(start, (end-start) >> PAGE_SHIFT); 790 791 printk(KERN_INFO "Testing CPA: again\n"); 792 set_memory_ro(start, (end-start) >> PAGE_SHIFT); 793 #endif 794 795 free_init_pages("unused kernel memory", 796 (unsigned long) page_address(virt_to_page(text_end)), 797 (unsigned long) 798 page_address(virt_to_page(rodata_start))); 799 free_init_pages("unused kernel memory", 800 (unsigned long) page_address(virt_to_page(rodata_end)), 801 (unsigned long) page_address(virt_to_page(data_start))); 802 } 803 804 #endif 805 806 int kern_addr_valid(unsigned long addr) 807 { 808 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; 809 pgd_t *pgd; 810 pud_t *pud; 811 pmd_t *pmd; 812 pte_t *pte; 813 814 if (above != 0 && above != -1UL) 815 return 0; 816 817 pgd = pgd_offset_k(addr); 818 if (pgd_none(*pgd)) 819 return 0; 820 821 pud = pud_offset(pgd, addr); 822 if (pud_none(*pud)) 823 return 0; 824 825 pmd = pmd_offset(pud, addr); 826 if (pmd_none(*pmd)) 827 return 0; 828 829 if (pmd_large(*pmd)) 830 return pfn_valid(pmd_pfn(*pmd)); 831 832 pte = pte_offset_kernel(pmd, addr); 833 if (pte_none(*pte)) 834 return 0; 835 836 return pfn_valid(pte_pfn(*pte)); 837 } 838 839 /* 840 * A pseudo VMA to allow ptrace access for the vsyscall page. This only 841 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does 842 * not need special handling anymore: 843 */ 844 static struct vm_area_struct gate_vma = { 845 .vm_start = VSYSCALL_START, 846 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE), 847 .vm_page_prot = PAGE_READONLY_EXEC, 848 .vm_flags = VM_READ | VM_EXEC 849 }; 850 851 struct vm_area_struct *get_gate_vma(struct mm_struct *mm) 852 { 853 #ifdef CONFIG_IA32_EMULATION 854 if (!mm || mm->context.ia32_compat) 855 return NULL; 856 #endif 857 return &gate_vma; 858 } 859 860 int in_gate_area(struct mm_struct *mm, unsigned long addr) 861 { 862 struct vm_area_struct *vma = get_gate_vma(mm); 863 864 if (!vma) 865 return 0; 866 867 return (addr >= vma->vm_start) && (addr < vma->vm_end); 868 } 869 870 /* 871 * Use this when you have no reliable mm, typically from interrupt 872 * context. It is less reliable than using a task's mm and may give 873 * false positives. 874 */ 875 int in_gate_area_no_mm(unsigned long addr) 876 { 877 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END); 878 } 879 880 const char *arch_vma_name(struct vm_area_struct *vma) 881 { 882 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) 883 return "[vdso]"; 884 if (vma == &gate_vma) 885 return "[vsyscall]"; 886 return NULL; 887 } 888 889 #ifdef CONFIG_X86_UV 890 unsigned long memory_block_size_bytes(void) 891 { 892 if (is_uv_system()) { 893 printk(KERN_INFO "UV: memory block size 2GB\n"); 894 return 2UL * 1024 * 1024 * 1024; 895 } 896 return MIN_MEMORY_BLOCK_SIZE; 897 } 898 #endif 899 900 #ifdef CONFIG_SPARSEMEM_VMEMMAP 901 /* 902 * Initialise the sparsemem vmemmap using huge-pages at the PMD level. 903 */ 904 static long __meminitdata addr_start, addr_end; 905 static void __meminitdata *p_start, *p_end; 906 static int __meminitdata node_start; 907 908 int __meminit 909 vmemmap_populate(struct page *start_page, unsigned long size, int node) 910 { 911 unsigned long addr = (unsigned long)start_page; 912 unsigned long end = (unsigned long)(start_page + size); 913 unsigned long next; 914 pgd_t *pgd; 915 pud_t *pud; 916 pmd_t *pmd; 917 918 for (; addr < end; addr = next) { 919 void *p = NULL; 920 921 pgd = vmemmap_pgd_populate(addr, node); 922 if (!pgd) 923 return -ENOMEM; 924 925 pud = vmemmap_pud_populate(pgd, addr, node); 926 if (!pud) 927 return -ENOMEM; 928 929 if (!cpu_has_pse) { 930 next = (addr + PAGE_SIZE) & PAGE_MASK; 931 pmd = vmemmap_pmd_populate(pud, addr, node); 932 933 if (!pmd) 934 return -ENOMEM; 935 936 p = vmemmap_pte_populate(pmd, addr, node); 937 938 if (!p) 939 return -ENOMEM; 940 941 addr_end = addr + PAGE_SIZE; 942 p_end = p + PAGE_SIZE; 943 } else { 944 next = pmd_addr_end(addr, end); 945 946 pmd = pmd_offset(pud, addr); 947 if (pmd_none(*pmd)) { 948 pte_t entry; 949 950 p = vmemmap_alloc_block_buf(PMD_SIZE, node); 951 if (!p) 952 return -ENOMEM; 953 954 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, 955 PAGE_KERNEL_LARGE); 956 set_pmd(pmd, __pmd(pte_val(entry))); 957 958 /* check to see if we have contiguous blocks */ 959 if (p_end != p || node_start != node) { 960 if (p_start) 961 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 962 addr_start, addr_end-1, p_start, p_end-1, node_start); 963 addr_start = addr; 964 node_start = node; 965 p_start = p; 966 } 967 968 addr_end = addr + PMD_SIZE; 969 p_end = p + PMD_SIZE; 970 } else 971 vmemmap_verify((pte_t *)pmd, node, addr, next); 972 } 973 974 } 975 sync_global_pgds((unsigned long)start_page, end); 976 return 0; 977 } 978 979 void __meminit vmemmap_populate_print_last(void) 980 { 981 if (p_start) { 982 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 983 addr_start, addr_end-1, p_start, p_end-1, node_start); 984 p_start = NULL; 985 p_end = NULL; 986 node_start = 0; 987 } 988 } 989 #endif 990