1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * fs/proc/kcore.c kernel ELF core dumper 4 * 5 * Modelled on fs/exec.c:aout_core_dump() 6 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 7 * ELF version written by David Howells <David.Howells@nexor.co.uk> 8 * Modified and incorporated into 2.3.x by Tigran Aivazian <tigran@veritas.com> 9 * Support to dump vmalloc'd areas (ELF only), Tigran Aivazian <tigran@veritas.com> 10 * Safe accesses to vmalloc/direct-mapped discontiguous areas, Kanoj Sarcar <kanoj@sgi.com> 11 */ 12 13 #include <linux/vmcore_info.h> 14 #include <linux/mm.h> 15 #include <linux/proc_fs.h> 16 #include <linux/kcore.h> 17 #include <linux/user.h> 18 #include <linux/capability.h> 19 #include <linux/elf.h> 20 #include <linux/elfcore.h> 21 #include <linux/vmalloc.h> 22 #include <linux/highmem.h> 23 #include <linux/printk.h> 24 #include <linux/memblock.h> 25 #include <linux/init.h> 26 #include <linux/slab.h> 27 #include <linux/uio.h> 28 #include <asm/io.h> 29 #include <linux/list.h> 30 #include <linux/ioport.h> 31 #include <linux/memory.h> 32 #include <linux/sched/task.h> 33 #include <linux/security.h> 34 #include <asm/sections.h> 35 #include "internal.h" 36 37 #define CORE_STR "CORE" 38 39 #ifndef ELF_CORE_EFLAGS 40 #define ELF_CORE_EFLAGS 0 41 #endif 42 43 static struct proc_dir_entry *proc_root_kcore; 44 45 46 #ifndef kc_vaddr_to_offset 47 #define kc_vaddr_to_offset(v) ((v) - PAGE_OFFSET) 48 #endif 49 #ifndef kc_offset_to_vaddr 50 #define kc_offset_to_vaddr(o) ((o) + PAGE_OFFSET) 51 #endif 52 53 #ifndef kc_xlate_dev_mem_ptr 54 #define kc_xlate_dev_mem_ptr kc_xlate_dev_mem_ptr 55 static inline void *kc_xlate_dev_mem_ptr(phys_addr_t phys) 56 { 57 return __va(phys); 58 } 59 #endif 60 #ifndef kc_unxlate_dev_mem_ptr 61 #define kc_unxlate_dev_mem_ptr kc_unxlate_dev_mem_ptr 62 static inline void kc_unxlate_dev_mem_ptr(phys_addr_t phys, void *virt) 63 { 64 } 65 #endif 66 67 static LIST_HEAD(kclist_head); 68 static DECLARE_RWSEM(kclist_lock); 69 static int kcore_need_update = 1; 70 71 /* 72 * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error 73 * Same as oldmem_pfn_is_ram in vmcore 74 */ 75 static int (*mem_pfn_is_ram)(unsigned long pfn); 76 77 int __init register_mem_pfn_is_ram(int (*fn)(unsigned long pfn)) 78 { 79 if (mem_pfn_is_ram) 80 return -EBUSY; 81 mem_pfn_is_ram = fn; 82 return 0; 83 } 84 85 static int pfn_is_ram(unsigned long pfn) 86 { 87 if (mem_pfn_is_ram) 88 return mem_pfn_is_ram(pfn); 89 else 90 return 1; 91 } 92 93 /* This doesn't grab kclist_lock, so it should only be used at init time. */ 94 void __init kclist_add(struct kcore_list *new, void *addr, size_t size, 95 int type) 96 { 97 new->addr = (unsigned long)addr; 98 new->size = size; 99 new->type = type; 100 101 list_add_tail(&new->list, &kclist_head); 102 } 103 104 static size_t get_kcore_size(int *nphdr, size_t *phdrs_len, size_t *notes_len, 105 size_t *data_offset) 106 { 107 size_t try, size; 108 struct kcore_list *m; 109 110 *nphdr = 1; /* PT_NOTE */ 111 size = 0; 112 113 list_for_each_entry(m, &kclist_head, list) { 114 try = kc_vaddr_to_offset((size_t)m->addr + m->size); 115 if (try > size) 116 size = try; 117 *nphdr = *nphdr + 1; 118 } 119 120 *phdrs_len = *nphdr * sizeof(struct elf_phdr); 121 *notes_len = (4 * sizeof(struct elf_note) + 122 3 * ALIGN(sizeof(CORE_STR), 4) + 123 VMCOREINFO_NOTE_NAME_BYTES + 124 ALIGN(sizeof(struct elf_prstatus), 4) + 125 ALIGN(sizeof(struct elf_prpsinfo), 4) + 126 ALIGN(arch_task_struct_size, 4) + 127 ALIGN(vmcoreinfo_size, 4)); 128 *data_offset = PAGE_ALIGN(sizeof(struct elfhdr) + *phdrs_len + 129 *notes_len); 130 return *data_offset + size; 131 } 132 133 #ifdef CONFIG_HIGHMEM 134 /* 135 * If no highmem, we can assume [0...max_low_pfn) continuous range of memory 136 * because memory hole is not as big as !HIGHMEM case. 137 * (HIGHMEM is special because part of memory is _invisible_ from the kernel.) 138 */ 139 static int kcore_ram_list(struct list_head *head) 140 { 141 struct kcore_list *ent; 142 143 ent = kmalloc(sizeof(*ent), GFP_KERNEL); 144 if (!ent) 145 return -ENOMEM; 146 ent->addr = (unsigned long)__va(0); 147 ent->size = max_low_pfn << PAGE_SHIFT; 148 ent->type = KCORE_RAM; 149 list_add(&ent->list, head); 150 return 0; 151 } 152 153 #else /* !CONFIG_HIGHMEM */ 154 155 #ifdef CONFIG_SPARSEMEM_VMEMMAP 156 /* calculate vmemmap's address from given system ram pfn and register it */ 157 static int 158 get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head) 159 { 160 unsigned long pfn = __pa(ent->addr) >> PAGE_SHIFT; 161 unsigned long nr_pages = ent->size >> PAGE_SHIFT; 162 unsigned long start, end; 163 struct kcore_list *vmm, *tmp; 164 165 166 start = ((unsigned long)pfn_to_page(pfn)) & PAGE_MASK; 167 end = ((unsigned long)pfn_to_page(pfn + nr_pages)) - 1; 168 end = PAGE_ALIGN(end); 169 /* overlap check (because we have to align page */ 170 list_for_each_entry(tmp, head, list) { 171 if (tmp->type != KCORE_VMEMMAP) 172 continue; 173 if (start < tmp->addr + tmp->size) 174 if (end > tmp->addr) 175 end = tmp->addr; 176 } 177 if (start < end) { 178 vmm = kmalloc(sizeof(*vmm), GFP_KERNEL); 179 if (!vmm) 180 return 0; 181 vmm->addr = start; 182 vmm->size = end - start; 183 vmm->type = KCORE_VMEMMAP; 184 list_add_tail(&vmm->list, head); 185 } 186 return 1; 187 188 } 189 #else 190 static int 191 get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head) 192 { 193 return 1; 194 } 195 196 #endif 197 198 static int 199 kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg) 200 { 201 struct list_head *head = (struct list_head *)arg; 202 struct kcore_list *ent; 203 struct page *p; 204 205 if (!pfn_valid(pfn)) 206 return 1; 207 208 p = pfn_to_page(pfn); 209 210 ent = kmalloc(sizeof(*ent), GFP_KERNEL); 211 if (!ent) 212 return -ENOMEM; 213 ent->addr = (unsigned long)page_to_virt(p); 214 ent->size = nr_pages << PAGE_SHIFT; 215 216 if (!virt_addr_valid((void *)ent->addr)) 217 goto free_out; 218 219 /* cut not-mapped area. ....from ppc-32 code. */ 220 if (ULONG_MAX - ent->addr < ent->size) 221 ent->size = ULONG_MAX - ent->addr; 222 223 /* 224 * We've already checked virt_addr_valid so we know this address 225 * is a valid pointer, therefore we can check against it to determine 226 * if we need to trim 227 */ 228 if (VMALLOC_START > ent->addr) { 229 if (VMALLOC_START - ent->addr < ent->size) 230 ent->size = VMALLOC_START - ent->addr; 231 } 232 233 ent->type = KCORE_RAM; 234 list_add_tail(&ent->list, head); 235 236 if (!get_sparsemem_vmemmap_info(ent, head)) { 237 list_del(&ent->list); 238 goto free_out; 239 } 240 241 return 0; 242 free_out: 243 kfree(ent); 244 return 1; 245 } 246 247 static int kcore_ram_list(struct list_head *list) 248 { 249 int nid, ret; 250 unsigned long end_pfn; 251 252 /* Not initialized....update now */ 253 /* find out "max pfn" */ 254 end_pfn = 0; 255 for_each_node_state(nid, N_MEMORY) { 256 unsigned long node_end; 257 node_end = node_end_pfn(nid); 258 if (end_pfn < node_end) 259 end_pfn = node_end; 260 } 261 /* scan 0 to max_pfn */ 262 ret = walk_system_ram_range(0, end_pfn, list, kclist_add_private); 263 if (ret) 264 return -ENOMEM; 265 return 0; 266 } 267 #endif /* CONFIG_HIGHMEM */ 268 269 static int kcore_update_ram(void) 270 { 271 LIST_HEAD(list); 272 LIST_HEAD(garbage); 273 int nphdr; 274 size_t phdrs_len, notes_len, data_offset; 275 struct kcore_list *tmp, *pos; 276 int ret = 0; 277 278 down_write(&kclist_lock); 279 if (!xchg(&kcore_need_update, 0)) 280 goto out; 281 282 ret = kcore_ram_list(&list); 283 if (ret) { 284 /* Couldn't get the RAM list, try again next time. */ 285 WRITE_ONCE(kcore_need_update, 1); 286 list_splice_tail(&list, &garbage); 287 goto out; 288 } 289 290 list_for_each_entry_safe(pos, tmp, &kclist_head, list) { 291 if (pos->type == KCORE_RAM || pos->type == KCORE_VMEMMAP) 292 list_move(&pos->list, &garbage); 293 } 294 list_splice_tail(&list, &kclist_head); 295 296 proc_root_kcore->size = get_kcore_size(&nphdr, &phdrs_len, ¬es_len, 297 &data_offset); 298 299 out: 300 up_write(&kclist_lock); 301 list_for_each_entry_safe(pos, tmp, &garbage, list) { 302 list_del(&pos->list); 303 kfree(pos); 304 } 305 return ret; 306 } 307 308 static void append_kcore_note(char *notes, size_t *i, const char *name, 309 unsigned int type, const void *desc, 310 size_t descsz) 311 { 312 struct elf_note *note = (struct elf_note *)¬es[*i]; 313 314 note->n_namesz = strlen(name) + 1; 315 note->n_descsz = descsz; 316 note->n_type = type; 317 *i += sizeof(*note); 318 memcpy(¬es[*i], name, note->n_namesz); 319 *i = ALIGN(*i + note->n_namesz, 4); 320 memcpy(¬es[*i], desc, descsz); 321 *i = ALIGN(*i + descsz, 4); 322 } 323 324 static ssize_t read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter) 325 { 326 struct file *file = iocb->ki_filp; 327 char *buf = file->private_data; 328 loff_t *fpos = &iocb->ki_pos; 329 size_t phdrs_offset, notes_offset, data_offset; 330 size_t page_offline_frozen = 1; 331 size_t phdrs_len, notes_len; 332 struct kcore_list *m; 333 size_t tsz; 334 int nphdr; 335 unsigned long start; 336 size_t buflen = iov_iter_count(iter); 337 size_t orig_buflen = buflen; 338 int ret = 0; 339 340 down_read(&kclist_lock); 341 /* 342 * Don't race against drivers that set PageOffline() and expect no 343 * further page access. 344 */ 345 page_offline_freeze(); 346 347 get_kcore_size(&nphdr, &phdrs_len, ¬es_len, &data_offset); 348 phdrs_offset = sizeof(struct elfhdr); 349 notes_offset = phdrs_offset + phdrs_len; 350 351 /* ELF file header. */ 352 if (buflen && *fpos < sizeof(struct elfhdr)) { 353 struct elfhdr ehdr = { 354 .e_ident = { 355 [EI_MAG0] = ELFMAG0, 356 [EI_MAG1] = ELFMAG1, 357 [EI_MAG2] = ELFMAG2, 358 [EI_MAG3] = ELFMAG3, 359 [EI_CLASS] = ELF_CLASS, 360 [EI_DATA] = ELF_DATA, 361 [EI_VERSION] = EV_CURRENT, 362 [EI_OSABI] = ELF_OSABI, 363 }, 364 .e_type = ET_CORE, 365 .e_machine = ELF_ARCH, 366 .e_version = EV_CURRENT, 367 .e_phoff = sizeof(struct elfhdr), 368 .e_flags = ELF_CORE_EFLAGS, 369 .e_ehsize = sizeof(struct elfhdr), 370 .e_phentsize = sizeof(struct elf_phdr), 371 .e_phnum = nphdr, 372 }; 373 374 tsz = min_t(size_t, buflen, sizeof(struct elfhdr) - *fpos); 375 if (copy_to_iter((char *)&ehdr + *fpos, tsz, iter) != tsz) { 376 ret = -EFAULT; 377 goto out; 378 } 379 380 buflen -= tsz; 381 *fpos += tsz; 382 } 383 384 /* ELF program headers. */ 385 if (buflen && *fpos < phdrs_offset + phdrs_len) { 386 struct elf_phdr *phdrs, *phdr; 387 388 phdrs = kzalloc(phdrs_len, GFP_KERNEL); 389 if (!phdrs) { 390 ret = -ENOMEM; 391 goto out; 392 } 393 394 phdrs[0].p_type = PT_NOTE; 395 phdrs[0].p_offset = notes_offset; 396 phdrs[0].p_filesz = notes_len; 397 398 phdr = &phdrs[1]; 399 list_for_each_entry(m, &kclist_head, list) { 400 phdr->p_type = PT_LOAD; 401 phdr->p_flags = PF_R | PF_W | PF_X; 402 phdr->p_offset = kc_vaddr_to_offset(m->addr) + data_offset; 403 phdr->p_vaddr = (size_t)m->addr; 404 if (m->type == KCORE_RAM) 405 phdr->p_paddr = __pa(m->addr); 406 else if (m->type == KCORE_TEXT) 407 phdr->p_paddr = __pa_symbol(m->addr); 408 else 409 phdr->p_paddr = (elf_addr_t)-1; 410 phdr->p_filesz = phdr->p_memsz = m->size; 411 phdr->p_align = PAGE_SIZE; 412 phdr++; 413 } 414 415 tsz = min_t(size_t, buflen, phdrs_offset + phdrs_len - *fpos); 416 if (copy_to_iter((char *)phdrs + *fpos - phdrs_offset, tsz, 417 iter) != tsz) { 418 kfree(phdrs); 419 ret = -EFAULT; 420 goto out; 421 } 422 kfree(phdrs); 423 424 buflen -= tsz; 425 *fpos += tsz; 426 } 427 428 /* ELF note segment. */ 429 if (buflen && *fpos < notes_offset + notes_len) { 430 struct elf_prstatus prstatus = {}; 431 struct elf_prpsinfo prpsinfo = { 432 .pr_sname = 'R', 433 .pr_fname = "vmlinux", 434 }; 435 char *notes; 436 size_t i = 0; 437 438 strscpy(prpsinfo.pr_psargs, saved_command_line, 439 sizeof(prpsinfo.pr_psargs)); 440 441 notes = kzalloc(notes_len, GFP_KERNEL); 442 if (!notes) { 443 ret = -ENOMEM; 444 goto out; 445 } 446 447 append_kcore_note(notes, &i, CORE_STR, NT_PRSTATUS, &prstatus, 448 sizeof(prstatus)); 449 append_kcore_note(notes, &i, CORE_STR, NT_PRPSINFO, &prpsinfo, 450 sizeof(prpsinfo)); 451 append_kcore_note(notes, &i, CORE_STR, NT_TASKSTRUCT, current, 452 arch_task_struct_size); 453 /* 454 * vmcoreinfo_size is mostly constant after init time, but it 455 * can be changed by crash_save_vmcoreinfo(). Racing here with a 456 * panic on another CPU before the machine goes down is insanely 457 * unlikely, but it's better to not leave potential buffer 458 * overflows lying around, regardless. 459 */ 460 append_kcore_note(notes, &i, VMCOREINFO_NOTE_NAME, 0, 461 vmcoreinfo_data, 462 min(vmcoreinfo_size, notes_len - i)); 463 464 tsz = min_t(size_t, buflen, notes_offset + notes_len - *fpos); 465 if (copy_to_iter(notes + *fpos - notes_offset, tsz, iter) != tsz) { 466 kfree(notes); 467 ret = -EFAULT; 468 goto out; 469 } 470 kfree(notes); 471 472 buflen -= tsz; 473 *fpos += tsz; 474 } 475 476 /* 477 * Check to see if our file offset matches with any of 478 * the addresses in the elf_phdr on our list. 479 */ 480 start = kc_offset_to_vaddr(*fpos - data_offset); 481 if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen) 482 tsz = buflen; 483 484 m = NULL; 485 while (buflen) { 486 struct page *page; 487 unsigned long pfn; 488 phys_addr_t phys; 489 void *__start; 490 491 /* 492 * If this is the first iteration or the address is not within 493 * the previous entry, search for a matching entry. 494 */ 495 if (!m || start < m->addr || start >= m->addr + m->size) { 496 struct kcore_list *iter; 497 498 m = NULL; 499 list_for_each_entry(iter, &kclist_head, list) { 500 if (start >= iter->addr && 501 start < iter->addr + iter->size) { 502 m = iter; 503 break; 504 } 505 } 506 } 507 508 if (page_offline_frozen++ % MAX_ORDER_NR_PAGES == 0) { 509 page_offline_thaw(); 510 cond_resched(); 511 page_offline_freeze(); 512 } 513 514 if (!m) { 515 if (iov_iter_zero(tsz, iter) != tsz) { 516 ret = -EFAULT; 517 goto out; 518 } 519 goto skip; 520 } 521 522 switch (m->type) { 523 case KCORE_VMALLOC: 524 { 525 const char *src = (char *)start; 526 size_t read = 0, left = tsz; 527 528 /* 529 * vmalloc uses spinlocks, so we optimistically try to 530 * read memory. If this fails, fault pages in and try 531 * again until we are done. 532 */ 533 while (true) { 534 read += vread_iter(iter, src, left); 535 if (read == tsz) 536 break; 537 538 src += read; 539 left -= read; 540 541 if (fault_in_iov_iter_writeable(iter, left)) { 542 ret = -EFAULT; 543 goto out; 544 } 545 } 546 break; 547 } 548 case KCORE_USER: 549 /* User page is handled prior to normal kernel page: */ 550 if (copy_to_iter((char *)start, tsz, iter) != tsz) { 551 ret = -EFAULT; 552 goto out; 553 } 554 break; 555 case KCORE_RAM: 556 phys = __pa(start); 557 pfn = phys >> PAGE_SHIFT; 558 page = pfn_to_online_page(pfn); 559 560 /* 561 * Don't read offline sections, logically offline pages 562 * (e.g., inflated in a balloon), hwpoisoned pages, 563 * and explicitly excluded physical ranges. 564 */ 565 if (!page || PageOffline(page) || 566 is_page_hwpoison(page) || !pfn_is_ram(pfn) || 567 pfn_is_unaccepted_memory(pfn)) { 568 if (iov_iter_zero(tsz, iter) != tsz) { 569 ret = -EFAULT; 570 goto out; 571 } 572 break; 573 } 574 fallthrough; 575 case KCORE_VMEMMAP: 576 case KCORE_TEXT: 577 if (m->type == KCORE_RAM) { 578 __start = kc_xlate_dev_mem_ptr(phys); 579 if (!__start) { 580 ret = -ENOMEM; 581 if (iov_iter_zero(tsz, iter) != tsz) 582 ret = -EFAULT; 583 goto out; 584 } 585 } else { 586 __start = (void *)start; 587 } 588 589 /* 590 * Sadly we must use a bounce buffer here to be able to 591 * make use of copy_from_kernel_nofault(), as these 592 * memory regions might not always be mapped on all 593 * architectures. 594 */ 595 ret = copy_from_kernel_nofault(buf, __start, tsz); 596 if (m->type == KCORE_RAM) 597 kc_unxlate_dev_mem_ptr(phys, __start); 598 if (ret) { 599 if (iov_iter_zero(tsz, iter) != tsz) { 600 ret = -EFAULT; 601 goto out; 602 } 603 /* 604 * We know the bounce buffer is safe to copy from, so 605 * use _copy_to_iter() directly. 606 */ 607 } else if (_copy_to_iter(buf, tsz, iter) != tsz) { 608 ret = -EFAULT; 609 goto out; 610 } 611 break; 612 default: 613 pr_warn_once("Unhandled KCORE type: %d\n", m->type); 614 if (iov_iter_zero(tsz, iter) != tsz) { 615 ret = -EFAULT; 616 goto out; 617 } 618 } 619 skip: 620 buflen -= tsz; 621 *fpos += tsz; 622 start += tsz; 623 tsz = (buflen > PAGE_SIZE ? PAGE_SIZE : buflen); 624 } 625 626 out: 627 page_offline_thaw(); 628 up_read(&kclist_lock); 629 if (ret) 630 return ret; 631 return orig_buflen - buflen; 632 } 633 634 static int open_kcore(struct inode *inode, struct file *filp) 635 { 636 int ret = security_locked_down(LOCKDOWN_KCORE); 637 638 if (!capable(CAP_SYS_RAWIO)) 639 return -EPERM; 640 641 if (ret) 642 return ret; 643 644 filp->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL); 645 if (!filp->private_data) 646 return -ENOMEM; 647 648 if (kcore_need_update) 649 kcore_update_ram(); 650 if (i_size_read(inode) != proc_root_kcore->size) { 651 inode_lock(inode); 652 i_size_write(inode, proc_root_kcore->size); 653 inode_unlock(inode); 654 } 655 return 0; 656 } 657 658 static int release_kcore(struct inode *inode, struct file *file) 659 { 660 kfree(file->private_data); 661 return 0; 662 } 663 664 static const struct proc_ops kcore_proc_ops = { 665 .proc_read_iter = read_kcore_iter, 666 .proc_open = open_kcore, 667 .proc_release = release_kcore, 668 .proc_lseek = default_llseek, 669 }; 670 671 /* just remember that we have to update kcore */ 672 static int __meminit kcore_callback(struct notifier_block *self, 673 unsigned long action, void *arg) 674 { 675 switch (action) { 676 case MEM_ONLINE: 677 case MEM_OFFLINE: 678 kcore_need_update = 1; 679 break; 680 } 681 return NOTIFY_OK; 682 } 683 684 685 static struct kcore_list kcore_vmalloc; 686 687 #ifdef CONFIG_ARCH_PROC_KCORE_TEXT 688 static struct kcore_list kcore_text; 689 /* 690 * If defined, special segment is used for mapping kernel text instead of 691 * direct-map area. We need to create special TEXT section. 692 */ 693 static void __init proc_kcore_text_init(void) 694 { 695 kclist_add(&kcore_text, _text, _end - _text, KCORE_TEXT); 696 } 697 #else 698 static void __init proc_kcore_text_init(void) 699 { 700 } 701 #endif 702 703 #if defined(CONFIG_MODULES) && defined(MODULES_VADDR) 704 /* 705 * MODULES_VADDR has no intersection with VMALLOC_ADDR. 706 */ 707 static struct kcore_list kcore_modules; 708 static void __init add_modules_range(void) 709 { 710 if (MODULES_VADDR != VMALLOC_START && MODULES_END != VMALLOC_END) { 711 kclist_add(&kcore_modules, (void *)MODULES_VADDR, 712 MODULES_END - MODULES_VADDR, KCORE_VMALLOC); 713 } 714 } 715 #else 716 static void __init add_modules_range(void) 717 { 718 } 719 #endif 720 721 static int __init proc_kcore_init(void) 722 { 723 proc_root_kcore = proc_create("kcore", S_IRUSR, NULL, &kcore_proc_ops); 724 if (!proc_root_kcore) { 725 pr_err("couldn't create /proc/kcore\n"); 726 return 0; /* Always returns 0. */ 727 } 728 /* Store text area if it's special */ 729 proc_kcore_text_init(); 730 /* Store vmalloc area */ 731 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 732 VMALLOC_END - VMALLOC_START, KCORE_VMALLOC); 733 add_modules_range(); 734 /* Store direct-map area from physical memory map */ 735 kcore_update_ram(); 736 hotplug_memory_notifier(kcore_callback, DEFAULT_CALLBACK_PRI); 737 738 return 0; 739 } 740 fs_initcall(proc_kcore_init); 741