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 pages++; 390 continue; 391 } 392 393 if (0) 394 printk(" pte=%p addr=%lx pte=%016lx\n", 395 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); 396 pages++; 397 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot)); 398 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; 399 } 400 401 update_page_count(PG_LEVEL_4K, pages); 402 403 return last_map_addr; 404 } 405 406 static unsigned long __meminit 407 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 408 unsigned long page_size_mask, pgprot_t prot) 409 { 410 unsigned long pages = 0, next; 411 unsigned long last_map_addr = end; 412 413 int i = pmd_index(address); 414 415 for (; i < PTRS_PER_PMD; i++, address = next) { 416 unsigned long pte_phys; 417 pmd_t *pmd = pmd_page + pmd_index(address); 418 pte_t *pte; 419 pgprot_t new_prot = prot; 420 421 if (address >= end) { 422 if (!after_bootmem) { 423 for (; i < PTRS_PER_PMD; i++, pmd++) 424 set_pmd(pmd, __pmd(0)); 425 } 426 break; 427 } 428 429 next = (address & PMD_MASK) + PMD_SIZE; 430 431 if (pmd_val(*pmd)) { 432 if (!pmd_large(*pmd)) { 433 spin_lock(&init_mm.page_table_lock); 434 pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); 435 last_map_addr = phys_pte_init(pte, address, 436 end, prot); 437 unmap_low_page(pte); 438 spin_unlock(&init_mm.page_table_lock); 439 continue; 440 } 441 /* 442 * If we are ok with PG_LEVEL_2M mapping, then we will 443 * use the existing mapping, 444 * 445 * Otherwise, we will split the large page mapping but 446 * use the same existing protection bits except for 447 * large page, so that we don't violate Intel's TLB 448 * Application note (317080) which says, while changing 449 * the page sizes, new and old translations should 450 * not differ with respect to page frame and 451 * attributes. 452 */ 453 if (page_size_mask & (1 << PG_LEVEL_2M)) { 454 last_map_addr = next; 455 continue; 456 } 457 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); 458 } 459 460 if (page_size_mask & (1<<PG_LEVEL_2M)) { 461 pages++; 462 spin_lock(&init_mm.page_table_lock); 463 set_pte((pte_t *)pmd, 464 pfn_pte(address >> PAGE_SHIFT, 465 __pgprot(pgprot_val(prot) | _PAGE_PSE))); 466 spin_unlock(&init_mm.page_table_lock); 467 last_map_addr = next; 468 continue; 469 } 470 471 pte = alloc_low_page(&pte_phys); 472 last_map_addr = phys_pte_init(pte, address, end, new_prot); 473 unmap_low_page(pte); 474 475 spin_lock(&init_mm.page_table_lock); 476 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); 477 spin_unlock(&init_mm.page_table_lock); 478 } 479 update_page_count(PG_LEVEL_2M, pages); 480 return last_map_addr; 481 } 482 483 static unsigned long __meminit 484 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 485 unsigned long page_size_mask) 486 { 487 unsigned long pages = 0, next; 488 unsigned long last_map_addr = end; 489 int i = pud_index(addr); 490 491 for (; i < PTRS_PER_PUD; i++, addr = next) { 492 unsigned long pmd_phys; 493 pud_t *pud = pud_page + pud_index(addr); 494 pmd_t *pmd; 495 pgprot_t prot = PAGE_KERNEL; 496 497 if (addr >= end) 498 break; 499 500 next = (addr & PUD_MASK) + PUD_SIZE; 501 502 if (!after_bootmem && !e820_any_mapped(addr, next, 0)) { 503 set_pud(pud, __pud(0)); 504 continue; 505 } 506 507 if (pud_val(*pud)) { 508 if (!pud_large(*pud)) { 509 pmd = map_low_page(pmd_offset(pud, 0)); 510 last_map_addr = phys_pmd_init(pmd, addr, end, 511 page_size_mask, prot); 512 unmap_low_page(pmd); 513 __flush_tlb_all(); 514 continue; 515 } 516 /* 517 * If we are ok with PG_LEVEL_1G mapping, then we will 518 * use the existing mapping. 519 * 520 * Otherwise, we will split the gbpage mapping but use 521 * the same existing protection bits except for large 522 * page, so that we don't violate Intel's TLB 523 * Application note (317080) which says, while changing 524 * the page sizes, new and old translations should 525 * not differ with respect to page frame and 526 * attributes. 527 */ 528 if (page_size_mask & (1 << PG_LEVEL_1G)) { 529 last_map_addr = next; 530 continue; 531 } 532 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); 533 } 534 535 if (page_size_mask & (1<<PG_LEVEL_1G)) { 536 pages++; 537 spin_lock(&init_mm.page_table_lock); 538 set_pte((pte_t *)pud, 539 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); 540 spin_unlock(&init_mm.page_table_lock); 541 last_map_addr = next; 542 continue; 543 } 544 545 pmd = alloc_low_page(&pmd_phys); 546 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, 547 prot); 548 unmap_low_page(pmd); 549 550 spin_lock(&init_mm.page_table_lock); 551 pud_populate(&init_mm, pud, __va(pmd_phys)); 552 spin_unlock(&init_mm.page_table_lock); 553 } 554 __flush_tlb_all(); 555 556 update_page_count(PG_LEVEL_1G, pages); 557 558 return last_map_addr; 559 } 560 561 unsigned long __meminit 562 kernel_physical_mapping_init(unsigned long start, 563 unsigned long end, 564 unsigned long page_size_mask) 565 { 566 bool pgd_changed = false; 567 unsigned long next, last_map_addr = end; 568 unsigned long addr; 569 570 start = (unsigned long)__va(start); 571 end = (unsigned long)__va(end); 572 addr = start; 573 574 for (; start < end; start = next) { 575 pgd_t *pgd = pgd_offset_k(start); 576 unsigned long pud_phys; 577 pud_t *pud; 578 579 next = (start + PGDIR_SIZE) & PGDIR_MASK; 580 if (next > end) 581 next = end; 582 583 if (pgd_val(*pgd)) { 584 pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); 585 last_map_addr = phys_pud_init(pud, __pa(start), 586 __pa(end), page_size_mask); 587 unmap_low_page(pud); 588 continue; 589 } 590 591 pud = alloc_low_page(&pud_phys); 592 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next), 593 page_size_mask); 594 unmap_low_page(pud); 595 596 spin_lock(&init_mm.page_table_lock); 597 pgd_populate(&init_mm, pgd, __va(pud_phys)); 598 spin_unlock(&init_mm.page_table_lock); 599 pgd_changed = true; 600 } 601 602 if (pgd_changed) 603 sync_global_pgds(addr, end); 604 605 __flush_tlb_all(); 606 607 return last_map_addr; 608 } 609 610 #ifndef CONFIG_NUMA 611 void __init initmem_init(void) 612 { 613 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0); 614 } 615 #endif 616 617 void __init paging_init(void) 618 { 619 sparse_memory_present_with_active_regions(MAX_NUMNODES); 620 sparse_init(); 621 622 /* 623 * clear the default setting with node 0 624 * note: don't use nodes_clear here, that is really clearing when 625 * numa support is not compiled in, and later node_set_state 626 * will not set it back. 627 */ 628 node_clear_state(0, N_NORMAL_MEMORY); 629 630 zone_sizes_init(); 631 } 632 633 /* 634 * Memory hotplug specific functions 635 */ 636 #ifdef CONFIG_MEMORY_HOTPLUG 637 /* 638 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need 639 * updating. 640 */ 641 static void update_end_of_memory_vars(u64 start, u64 size) 642 { 643 unsigned long end_pfn = PFN_UP(start + size); 644 645 if (end_pfn > max_pfn) { 646 max_pfn = end_pfn; 647 max_low_pfn = end_pfn; 648 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; 649 } 650 } 651 652 /* 653 * Memory is added always to NORMAL zone. This means you will never get 654 * additional DMA/DMA32 memory. 655 */ 656 int arch_add_memory(int nid, u64 start, u64 size) 657 { 658 struct pglist_data *pgdat = NODE_DATA(nid); 659 struct zone *zone = pgdat->node_zones + ZONE_NORMAL; 660 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT; 661 unsigned long nr_pages = size >> PAGE_SHIFT; 662 int ret; 663 664 last_mapped_pfn = init_memory_mapping(start, start + size); 665 if (last_mapped_pfn > max_pfn_mapped) 666 max_pfn_mapped = last_mapped_pfn; 667 668 ret = __add_pages(nid, zone, start_pfn, nr_pages); 669 WARN_ON_ONCE(ret); 670 671 /* update max_pfn, max_low_pfn and high_memory */ 672 update_end_of_memory_vars(start, size); 673 674 return ret; 675 } 676 EXPORT_SYMBOL_GPL(arch_add_memory); 677 678 #endif /* CONFIG_MEMORY_HOTPLUG */ 679 680 static struct kcore_list kcore_vsyscall; 681 682 void __init mem_init(void) 683 { 684 long codesize, reservedpages, datasize, initsize; 685 unsigned long absent_pages; 686 687 pci_iommu_alloc(); 688 689 /* clear_bss() already clear the empty_zero_page */ 690 691 reservedpages = 0; 692 693 /* this will put all low memory onto the freelists */ 694 #ifdef CONFIG_NUMA 695 totalram_pages = numa_free_all_bootmem(); 696 #else 697 totalram_pages = free_all_bootmem(); 698 #endif 699 700 absent_pages = absent_pages_in_range(0, max_pfn); 701 reservedpages = max_pfn - totalram_pages - absent_pages; 702 after_bootmem = 1; 703 704 codesize = (unsigned long) &_etext - (unsigned long) &_text; 705 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 706 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 707 708 /* Register memory areas for /proc/kcore */ 709 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, 710 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER); 711 712 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, " 713 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n", 714 nr_free_pages() << (PAGE_SHIFT-10), 715 max_pfn << (PAGE_SHIFT-10), 716 codesize >> 10, 717 absent_pages << (PAGE_SHIFT-10), 718 reservedpages << (PAGE_SHIFT-10), 719 datasize >> 10, 720 initsize >> 10); 721 } 722 723 #ifdef CONFIG_DEBUG_RODATA 724 const int rodata_test_data = 0xC3; 725 EXPORT_SYMBOL_GPL(rodata_test_data); 726 727 int kernel_set_to_readonly; 728 729 void set_kernel_text_rw(void) 730 { 731 unsigned long start = PFN_ALIGN(_text); 732 unsigned long end = PFN_ALIGN(__stop___ex_table); 733 734 if (!kernel_set_to_readonly) 735 return; 736 737 pr_debug("Set kernel text: %lx - %lx for read write\n", 738 start, end); 739 740 /* 741 * Make the kernel identity mapping for text RW. Kernel text 742 * mapping will always be RO. Refer to the comment in 743 * static_protections() in pageattr.c 744 */ 745 set_memory_rw(start, (end - start) >> PAGE_SHIFT); 746 } 747 748 void set_kernel_text_ro(void) 749 { 750 unsigned long start = PFN_ALIGN(_text); 751 unsigned long end = PFN_ALIGN(__stop___ex_table); 752 753 if (!kernel_set_to_readonly) 754 return; 755 756 pr_debug("Set kernel text: %lx - %lx for read only\n", 757 start, end); 758 759 /* 760 * Set the kernel identity mapping for text RO. 761 */ 762 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 763 } 764 765 void mark_rodata_ro(void) 766 { 767 unsigned long start = PFN_ALIGN(_text); 768 unsigned long rodata_start = 769 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; 770 unsigned long end = (unsigned long) &__end_rodata_hpage_align; 771 unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table); 772 unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata); 773 unsigned long data_start = (unsigned long) &_sdata; 774 775 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 776 (end - start) >> 10); 777 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 778 779 kernel_set_to_readonly = 1; 780 781 /* 782 * The rodata section (but not the kernel text!) should also be 783 * not-executable. 784 */ 785 set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); 786 787 rodata_test(); 788 789 #ifdef CONFIG_CPA_DEBUG 790 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end); 791 set_memory_rw(start, (end-start) >> PAGE_SHIFT); 792 793 printk(KERN_INFO "Testing CPA: again\n"); 794 set_memory_ro(start, (end-start) >> PAGE_SHIFT); 795 #endif 796 797 free_init_pages("unused kernel memory", 798 (unsigned long) page_address(virt_to_page(text_end)), 799 (unsigned long) 800 page_address(virt_to_page(rodata_start))); 801 free_init_pages("unused kernel memory", 802 (unsigned long) page_address(virt_to_page(rodata_end)), 803 (unsigned long) page_address(virt_to_page(data_start))); 804 } 805 806 #endif 807 808 int kern_addr_valid(unsigned long addr) 809 { 810 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; 811 pgd_t *pgd; 812 pud_t *pud; 813 pmd_t *pmd; 814 pte_t *pte; 815 816 if (above != 0 && above != -1UL) 817 return 0; 818 819 pgd = pgd_offset_k(addr); 820 if (pgd_none(*pgd)) 821 return 0; 822 823 pud = pud_offset(pgd, addr); 824 if (pud_none(*pud)) 825 return 0; 826 827 pmd = pmd_offset(pud, addr); 828 if (pmd_none(*pmd)) 829 return 0; 830 831 if (pmd_large(*pmd)) 832 return pfn_valid(pmd_pfn(*pmd)); 833 834 pte = pte_offset_kernel(pmd, addr); 835 if (pte_none(*pte)) 836 return 0; 837 838 return pfn_valid(pte_pfn(*pte)); 839 } 840 841 /* 842 * A pseudo VMA to allow ptrace access for the vsyscall page. This only 843 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does 844 * not need special handling anymore: 845 */ 846 static struct vm_area_struct gate_vma = { 847 .vm_start = VSYSCALL_START, 848 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE), 849 .vm_page_prot = PAGE_READONLY_EXEC, 850 .vm_flags = VM_READ | VM_EXEC 851 }; 852 853 struct vm_area_struct *get_gate_vma(struct mm_struct *mm) 854 { 855 #ifdef CONFIG_IA32_EMULATION 856 if (!mm || mm->context.ia32_compat) 857 return NULL; 858 #endif 859 return &gate_vma; 860 } 861 862 int in_gate_area(struct mm_struct *mm, unsigned long addr) 863 { 864 struct vm_area_struct *vma = get_gate_vma(mm); 865 866 if (!vma) 867 return 0; 868 869 return (addr >= vma->vm_start) && (addr < vma->vm_end); 870 } 871 872 /* 873 * Use this when you have no reliable mm, typically from interrupt 874 * context. It is less reliable than using a task's mm and may give 875 * false positives. 876 */ 877 int in_gate_area_no_mm(unsigned long addr) 878 { 879 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END); 880 } 881 882 const char *arch_vma_name(struct vm_area_struct *vma) 883 { 884 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) 885 return "[vdso]"; 886 if (vma == &gate_vma) 887 return "[vsyscall]"; 888 return NULL; 889 } 890 891 #ifdef CONFIG_X86_UV 892 unsigned long memory_block_size_bytes(void) 893 { 894 if (is_uv_system()) { 895 printk(KERN_INFO "UV: memory block size 2GB\n"); 896 return 2UL * 1024 * 1024 * 1024; 897 } 898 return MIN_MEMORY_BLOCK_SIZE; 899 } 900 #endif 901 902 #ifdef CONFIG_SPARSEMEM_VMEMMAP 903 /* 904 * Initialise the sparsemem vmemmap using huge-pages at the PMD level. 905 */ 906 static long __meminitdata addr_start, addr_end; 907 static void __meminitdata *p_start, *p_end; 908 static int __meminitdata node_start; 909 910 int __meminit 911 vmemmap_populate(struct page *start_page, unsigned long size, int node) 912 { 913 unsigned long addr = (unsigned long)start_page; 914 unsigned long end = (unsigned long)(start_page + size); 915 unsigned long next; 916 pgd_t *pgd; 917 pud_t *pud; 918 pmd_t *pmd; 919 920 for (; addr < end; addr = next) { 921 void *p = NULL; 922 923 pgd = vmemmap_pgd_populate(addr, node); 924 if (!pgd) 925 return -ENOMEM; 926 927 pud = vmemmap_pud_populate(pgd, addr, node); 928 if (!pud) 929 return -ENOMEM; 930 931 if (!cpu_has_pse) { 932 next = (addr + PAGE_SIZE) & PAGE_MASK; 933 pmd = vmemmap_pmd_populate(pud, addr, node); 934 935 if (!pmd) 936 return -ENOMEM; 937 938 p = vmemmap_pte_populate(pmd, addr, node); 939 940 if (!p) 941 return -ENOMEM; 942 943 addr_end = addr + PAGE_SIZE; 944 p_end = p + PAGE_SIZE; 945 } else { 946 next = pmd_addr_end(addr, end); 947 948 pmd = pmd_offset(pud, addr); 949 if (pmd_none(*pmd)) { 950 pte_t entry; 951 952 p = vmemmap_alloc_block_buf(PMD_SIZE, node); 953 if (!p) 954 return -ENOMEM; 955 956 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, 957 PAGE_KERNEL_LARGE); 958 set_pmd(pmd, __pmd(pte_val(entry))); 959 960 /* check to see if we have contiguous blocks */ 961 if (p_end != p || node_start != node) { 962 if (p_start) 963 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 964 addr_start, addr_end-1, p_start, p_end-1, node_start); 965 addr_start = addr; 966 node_start = node; 967 p_start = p; 968 } 969 970 addr_end = addr + PMD_SIZE; 971 p_end = p + PMD_SIZE; 972 } else 973 vmemmap_verify((pte_t *)pmd, node, addr, next); 974 } 975 976 } 977 sync_global_pgds((unsigned long)start_page, end); 978 return 0; 979 } 980 981 void __meminit vmemmap_populate_print_last(void) 982 { 983 if (p_start) { 984 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 985 addr_start, addr_end-1, p_start, p_end-1, node_start); 986 p_start = NULL; 987 p_end = NULL; 988 node_start = 0; 989 } 990 } 991 #endif 992