SAFE public projects git trees. - safe/jmp/linux-2.6/blob - fs/proc/vmcore.c

   1 /*
   2  *      fs/proc/vmcore.c Interface for accessing the crash
   3  *                               dump from the system's previous life.
   4  *      Heavily borrowed from fs/proc/kcore.c
   5  *      Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
   6  *      Copyright (C) IBM Corporation, 2004. All rights reserved
   7  *
   8  */
   9
  10 #include <linux/mm.h>
  11 #include <linux/proc_fs.h>
  12 #include <linux/user.h>
  13 #include <linux/elf.h>
  14 #include <linux/elfcore.h>
  15 #include <linux/highmem.h>
  16 #include <linux/bootmem.h>
  17 #include <linux/init.h>
  18 #include <linux/crash_dump.h>
  19 #include <linux/list.h>
  20 #include <asm/uaccess.h>
  21 #include <asm/io.h>
  22
  23 /* List representing chunks of contiguous memory areas and their offsets in
  24  * vmcore file.
  25  */
  26 static LIST_HEAD(vmcore_list);
  27
  28 /* Stores the pointer to the buffer containing kernel elf core headers. */
  29 static char *elfcorebuf;
  30 static size_t elfcorebuf_sz;
  31
  32 /* Total size of vmcore file. */
  33 static u64 vmcore_size;
  34
  35 /* Stores the physical address of elf header of crash image. */
  36 unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
  37
  38 struct proc_dir_entry *proc_vmcore = NULL;
  39
  40 /* Reads a page from the oldmem device from given offset. */
  41 static ssize_t read_from_oldmem(char *buf, size_t count,
  42                                 u64 *ppos, int userbuf)
  43 {
  44         unsigned long pfn, offset;
  45         size_t nr_bytes;
  46         ssize_t read = 0, tmp;
  47
  48         if (!count)
  49                 return 0;
  50
  51         offset = (unsigned long)(*ppos % PAGE_SIZE);
  52         pfn = (unsigned long)(*ppos / PAGE_SIZE);
  53         if (pfn > saved_max_pfn)
  54                 return -EINVAL;
  55
  56         do {
  57                 if (count > (PAGE_SIZE - offset))
  58                         nr_bytes = PAGE_SIZE - offset;
  59                 else
  60                         nr_bytes = count;
  61
  62                 tmp = copy_oldmem_page(pfn, buf, nr_bytes, offset, userbuf);
  63                 if (tmp < 0)
  64                         return tmp;
  65                 *ppos += nr_bytes;
  66                 count -= nr_bytes;
  67                 buf += nr_bytes;
  68                 read += nr_bytes;
  69                 ++pfn;
  70                 offset = 0;
  71         } while (count);
  72
  73         return read;
  74 }
  75
  76 /* Maps vmcore file offset to respective physical address in memroy. */
  77 static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list,
  78                                         struct vmcore **m_ptr)
  79 {
  80         struct vmcore *m;
  81         u64 paddr;
  82
  83         list_for_each_entry(m, vc_list, list) {
  84                 u64 start, end;
  85                 start = m->offset;
  86                 end = m->offset + m->size - 1;
  87                 if (offset >= start && offset <= end) {
  88                         paddr = m->paddr + offset - start;
  89                         *m_ptr = m;
  90                         return paddr;
  91                 }
  92         }
  93         *m_ptr = NULL;
  94         return 0;
  95 }
  96
  97 /* Read from the ELF header and then the crash dump. On error, negative value is
  98  * returned otherwise number of bytes read are returned.
  99  */
 100 static ssize_t read_vmcore(struct file *file, char __user *buffer,
 101                                 size_t buflen, loff_t *fpos)
 102 {
 103         ssize_t acc = 0, tmp;
 104         size_t tsz;
 105         u64 start, nr_bytes;
 106         struct vmcore *curr_m = NULL;
 107
 108         if (buflen == 0 || *fpos >= vmcore_size)
 109                 return 0;
 110
 111         /* trim buflen to not go beyond EOF */
 112         if (buflen > vmcore_size - *fpos)
 113                 buflen = vmcore_size - *fpos;
 114
 115         /* Read ELF core header */
 116         if (*fpos < elfcorebuf_sz) {
 117                 tsz = elfcorebuf_sz - *fpos;
 118                 if (buflen < tsz)
 119                         tsz = buflen;
 120                 if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
 121                         return -EFAULT;
 122                 buflen -= tsz;
 123                 *fpos += tsz;
 124                 buffer += tsz;
 125                 acc += tsz;
 126
 127                 /* leave now if filled buffer already */
 128                 if (buflen == 0)
 129                         return acc;
 130         }
 131
 132         start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m);
 133         if (!curr_m)
 134                 return -EINVAL;
 135         if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
 136                 tsz = buflen;
 137
 138         /* Calculate left bytes in current memory segment. */
 139         nr_bytes = (curr_m->size - (start - curr_m->paddr));
 140         if (tsz > nr_bytes)
 141                 tsz = nr_bytes;
 142
 143         while (buflen) {
 144                 tmp = read_from_oldmem(buffer, tsz, &start, 1);
 145                 if (tmp < 0)
 146                         return tmp;
 147                 buflen -= tsz;
 148                 *fpos += tsz;
 149                 buffer += tsz;
 150                 acc += tsz;
 151                 if (start >= (curr_m->paddr + curr_m->size)) {
 152                         if (curr_m->list.next == &vmcore_list)
 153                                 return acc;     /*EOF*/
 154                         curr_m = list_entry(curr_m->list.next,
 155                                                 struct vmcore, list);
 156                         start = curr_m->paddr;
 157                 }
 158                 if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
 159                         tsz = buflen;
 160                 /* Calculate left bytes in current memory segment. */
 161                 nr_bytes = (curr_m->size - (start - curr_m->paddr));
 162                 if (tsz > nr_bytes)
 163                         tsz = nr_bytes;
 164         }
 165         return acc;
 166 }
 167
 168 const struct file_operations proc_vmcore_operations = {
 169         .read           = read_vmcore,
 170 };
 171
 172 static struct vmcore* __init get_new_element(void)
 173 {
 174         struct vmcore *p;
 175
 176         p = kmalloc(sizeof(*p), GFP_KERNEL);
 177         if (p)
 178                 memset(p, 0, sizeof(*p));
 179         return p;
 180 }
 181
 182 static u64 __init get_vmcore_size_elf64(char *elfptr)
 183 {
 184         int i;
 185         u64 size;
 186         Elf64_Ehdr *ehdr_ptr;
 187         Elf64_Phdr *phdr_ptr;
 188
 189         ehdr_ptr = (Elf64_Ehdr *)elfptr;
 190         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
 191         size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr));
 192         for (i = 0; i < ehdr_ptr->e_phnum; i++) {
 193                 size += phdr_ptr->p_memsz;
 194                 phdr_ptr++;
 195         }
 196         return size;
 197 }
 198
 199 static u64 __init get_vmcore_size_elf32(char *elfptr)
 200 {
 201         int i;
 202         u64 size;
 203         Elf32_Ehdr *ehdr_ptr;
 204         Elf32_Phdr *phdr_ptr;
 205
 206         ehdr_ptr = (Elf32_Ehdr *)elfptr;
 207         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
 208         size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
 209         for (i = 0; i < ehdr_ptr->e_phnum; i++) {
 210                 size += phdr_ptr->p_memsz;
 211                 phdr_ptr++;
 212         }
 213         return size;
 214 }
 215
 216 /* Merges all the PT_NOTE headers into one. */
 217 static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
 218                                                 struct list_head *vc_list)
 219 {
 220         int i, nr_ptnote=0, rc=0;
 221         char *tmp;
 222         Elf64_Ehdr *ehdr_ptr;
 223         Elf64_Phdr phdr, *phdr_ptr;
 224         Elf64_Nhdr *nhdr_ptr;
 225         u64 phdr_sz = 0, note_off;
 226
 227         ehdr_ptr = (Elf64_Ehdr *)elfptr;
 228         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
 229         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
 230                 int j;
 231                 void *notes_section;
 232                 struct vmcore *new;
 233                 u64 offset, max_sz, sz, real_sz = 0;
 234                 if (phdr_ptr->p_type != PT_NOTE)
 235                         continue;
 236                 nr_ptnote++;
 237                 max_sz = phdr_ptr->p_memsz;
 238                 offset = phdr_ptr->p_offset;
 239                 notes_section = kmalloc(max_sz, GFP_KERNEL);
 240                 if (!notes_section)
 241                         return -ENOMEM;
 242                 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
 243                 if (rc < 0) {
 244                         kfree(notes_section);
 245                         return rc;
 246                 }
 247                 nhdr_ptr = notes_section;
 248                 for (j = 0; j < max_sz; j += sz) {
 249                         if (nhdr_ptr->n_namesz == 0)
 250                                 break;
 251                         sz = sizeof(Elf64_Nhdr) +
 252                                 ((nhdr_ptr->n_namesz + 3) & ~3) +
 253                                 ((nhdr_ptr->n_descsz + 3) & ~3);
 254                         real_sz += sz;
 255                         nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
 256                 }
 257
 258                 /* Add this contiguous chunk of notes section to vmcore list.*/
 259                 new = get_new_element();
 260                 if (!new) {
 261                         kfree(notes_section);
 262                         return -ENOMEM;
 263                 }
 264                 new->paddr = phdr_ptr->p_offset;
 265                 new->size = real_sz;
 266                 list_add_tail(&new->list, vc_list);
 267                 phdr_sz += real_sz;
 268                 kfree(notes_section);
 269         }
 270
 271         /* Prepare merged PT_NOTE program header. */
 272         phdr.p_type    = PT_NOTE;
 273         phdr.p_flags   = 0;
 274         note_off = sizeof(Elf64_Ehdr) +
 275                         (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
 276         phdr.p_offset  = note_off;
 277         phdr.p_vaddr   = phdr.p_paddr = 0;
 278         phdr.p_filesz  = phdr.p_memsz = phdr_sz;
 279         phdr.p_align   = 0;
 280
 281         /* Add merged PT_NOTE program header*/
 282         tmp = elfptr + sizeof(Elf64_Ehdr);
 283         memcpy(tmp, &phdr, sizeof(phdr));
 284         tmp += sizeof(phdr);
 285
 286         /* Remove unwanted PT_NOTE program headers. */
 287         i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
 288         *elfsz = *elfsz - i;
 289         memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
 290
 291         /* Modify e_phnum to reflect merged headers. */
 292         ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
 293
 294         return 0;
 295 }
 296
 297 /* Merges all the PT_NOTE headers into one. */
 298 static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
 299                                                 struct list_head *vc_list)
 300 {
 301         int i, nr_ptnote=0, rc=0;
 302         char *tmp;
 303         Elf32_Ehdr *ehdr_ptr;
 304         Elf32_Phdr phdr, *phdr_ptr;
 305         Elf32_Nhdr *nhdr_ptr;
 306         u64 phdr_sz = 0, note_off;
 307
 308         ehdr_ptr = (Elf32_Ehdr *)elfptr;
 309         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
 310         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
 311                 int j;
 312                 void *notes_section;
 313                 struct vmcore *new;
 314                 u64 offset, max_sz, sz, real_sz = 0;
 315                 if (phdr_ptr->p_type != PT_NOTE)
 316                         continue;
 317                 nr_ptnote++;
 318                 max_sz = phdr_ptr->p_memsz;
 319                 offset = phdr_ptr->p_offset;
 320                 notes_section = kmalloc(max_sz, GFP_KERNEL);
 321                 if (!notes_section)
 322                         return -ENOMEM;
 323                 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
 324                 if (rc < 0) {
 325                         kfree(notes_section);
 326                         return rc;
 327                 }
 328                 nhdr_ptr = notes_section;
 329                 for (j = 0; j < max_sz; j += sz) {
 330                         if (nhdr_ptr->n_namesz == 0)
 331                                 break;
 332                         sz = sizeof(Elf32_Nhdr) +
 333                                 ((nhdr_ptr->n_namesz + 3) & ~3) +
 334                                 ((nhdr_ptr->n_descsz + 3) & ~3);
 335                         real_sz += sz;
 336                         nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
 337                 }
 338
 339                 /* Add this contiguous chunk of notes section to vmcore list.*/
 340                 new = get_new_element();
 341                 if (!new) {
 342                         kfree(notes_section);
 343                         return -ENOMEM;
 344                 }
 345                 new->paddr = phdr_ptr->p_offset;
 346                 new->size = real_sz;
 347                 list_add_tail(&new->list, vc_list);
 348                 phdr_sz += real_sz;
 349                 kfree(notes_section);
 350         }
 351
 352         /* Prepare merged PT_NOTE program header. */
 353         phdr.p_type    = PT_NOTE;
 354         phdr.p_flags   = 0;
 355         note_off = sizeof(Elf32_Ehdr) +
 356                         (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
 357         phdr.p_offset  = note_off;
 358         phdr.p_vaddr   = phdr.p_paddr = 0;
 359         phdr.p_filesz  = phdr.p_memsz = phdr_sz;
 360         phdr.p_align   = 0;
 361
 362         /* Add merged PT_NOTE program header*/
 363         tmp = elfptr + sizeof(Elf32_Ehdr);
 364         memcpy(tmp, &phdr, sizeof(phdr));
 365         tmp += sizeof(phdr);
 366
 367         /* Remove unwanted PT_NOTE program headers. */
 368         i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
 369         *elfsz = *elfsz - i;
 370         memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
 371
 372         /* Modify e_phnum to reflect merged headers. */
 373         ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
 374
 375         return 0;
 376 }
 377
 378 /* Add memory chunks represented by program headers to vmcore list. Also update
 379  * the new offset fields of exported program headers. */
 380 static int __init process_ptload_program_headers_elf64(char *elfptr,
 381                                                 size_t elfsz,
 382                                                 struct list_head *vc_list)
 383 {
 384         int i;
 385         Elf64_Ehdr *ehdr_ptr;
 386         Elf64_Phdr *phdr_ptr;
 387         loff_t vmcore_off;
 388         struct vmcore *new;
 389
 390         ehdr_ptr = (Elf64_Ehdr *)elfptr;
 391         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
 392
 393         /* First program header is PT_NOTE header. */
 394         vmcore_off = sizeof(Elf64_Ehdr) +
 395                         (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
 396                         phdr_ptr->p_memsz; /* Note sections */
 397
 398         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
 399                 if (phdr_ptr->p_type != PT_LOAD)
 400                         continue;
 401
 402                 /* Add this contiguous chunk of memory to vmcore list.*/
 403                 new = get_new_element();
 404                 if (!new)
 405                         return -ENOMEM;
 406                 new->paddr = phdr_ptr->p_offset;
 407                 new->size = phdr_ptr->p_memsz;
 408                 list_add_tail(&new->list, vc_list);
 409
 410                 /* Update the program header offset. */
 411                 phdr_ptr->p_offset = vmcore_off;
 412                 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
 413         }
 414         return 0;
 415 }
 416
 417 static int __init process_ptload_program_headers_elf32(char *elfptr,
 418                                                 size_t elfsz,
 419                                                 struct list_head *vc_list)
 420 {
 421         int i;
 422         Elf32_Ehdr *ehdr_ptr;
 423         Elf32_Phdr *phdr_ptr;
 424         loff_t vmcore_off;
 425         struct vmcore *new;
 426
 427         ehdr_ptr = (Elf32_Ehdr *)elfptr;
 428         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
 429
 430         /* First program header is PT_NOTE header. */
 431         vmcore_off = sizeof(Elf32_Ehdr) +
 432                         (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
 433                         phdr_ptr->p_memsz; /* Note sections */
 434
 435         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
 436                 if (phdr_ptr->p_type != PT_LOAD)
 437                         continue;
 438
 439                 /* Add this contiguous chunk of memory to vmcore list.*/
 440                 new = get_new_element();
 441                 if (!new)
 442                         return -ENOMEM;
 443                 new->paddr = phdr_ptr->p_offset;
 444                 new->size = phdr_ptr->p_memsz;
 445                 list_add_tail(&new->list, vc_list);
 446
 447                 /* Update the program header offset */
 448                 phdr_ptr->p_offset = vmcore_off;
 449                 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
 450         }
 451         return 0;
 452 }
 453
 454 /* Sets offset fields of vmcore elements. */
 455 static void __init set_vmcore_list_offsets_elf64(char *elfptr,
 456                                                 struct list_head *vc_list)
 457 {
 458         loff_t vmcore_off;
 459         Elf64_Ehdr *ehdr_ptr;
 460         struct vmcore *m;
 461
 462         ehdr_ptr = (Elf64_Ehdr *)elfptr;
 463
 464         /* Skip Elf header and program headers. */
 465         vmcore_off = sizeof(Elf64_Ehdr) +
 466                         (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr);
 467
 468         list_for_each_entry(m, vc_list, list) {
 469                 m->offset = vmcore_off;
 470                 vmcore_off += m->size;
 471         }
 472 }
 473
 474 /* Sets offset fields of vmcore elements. */
 475 static void __init set_vmcore_list_offsets_elf32(char *elfptr,
 476                                                 struct list_head *vc_list)
 477 {
 478         loff_t vmcore_off;
 479         Elf32_Ehdr *ehdr_ptr;
 480         struct vmcore *m;
 481
 482         ehdr_ptr = (Elf32_Ehdr *)elfptr;
 483
 484         /* Skip Elf header and program headers. */
 485         vmcore_off = sizeof(Elf32_Ehdr) +
 486                         (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);
 487
 488         list_for_each_entry(m, vc_list, list) {
 489                 m->offset = vmcore_off;
 490                 vmcore_off += m->size;
 491         }
 492 }
 493
 494 static int __init parse_crash_elf64_headers(void)
 495 {
 496         int rc=0;
 497         Elf64_Ehdr ehdr;
 498         u64 addr;
 499
 500         addr = elfcorehdr_addr;
 501
 502         /* Read Elf header */
 503         rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0);
 504         if (rc < 0)
 505                 return rc;
 506
 507         /* Do some basic Verification. */
 508         if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
 509                 (ehdr.e_type != ET_CORE) ||
 510                 !vmcore_elf_check_arch(&ehdr) ||
 511                 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
 512                 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
 513                 ehdr.e_version != EV_CURRENT ||
 514                 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
 515                 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
 516                 ehdr.e_phnum == 0) {
 517                 printk(KERN_WARNING "Warning: Core image elf header is not"
 518                                         "sane\n");
 519                 return -EINVAL;
 520         }
 521
 522         /* Read in all elf headers. */
 523         elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr);
 524         elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
 525         if (!elfcorebuf)
 526                 return -ENOMEM;
 527         addr = elfcorehdr_addr;
 528         rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
 529         if (rc < 0) {
 530                 kfree(elfcorebuf);
 531                 return rc;
 532         }
 533
 534         /* Merge all PT_NOTE headers into one. */
 535         rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
 536         if (rc) {
 537                 kfree(elfcorebuf);
 538                 return rc;
 539         }
 540         rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
 541                                                         &vmcore_list);
 542         if (rc) {
 543                 kfree(elfcorebuf);
 544                 return rc;
 545         }
 546         set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list);
 547         return 0;
 548 }
 549
 550 static int __init parse_crash_elf32_headers(void)
 551 {
 552         int rc=0;
 553         Elf32_Ehdr ehdr;
 554         u64 addr;
 555
 556         addr = elfcorehdr_addr;
 557
 558         /* Read Elf header */
 559         rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
 560         if (rc < 0)
 561                 return rc;
 562
 563         /* Do some basic Verification. */
 564         if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
 565                 (ehdr.e_type != ET_CORE) ||
 566                 !elf_check_arch(&ehdr) ||
 567                 ehdr.e_ident[EI_CLASS] != ELFCLASS32||
 568                 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
 569                 ehdr.e_version != EV_CURRENT ||
 570                 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
 571                 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
 572                 ehdr.e_phnum == 0) {
 573                 printk(KERN_WARNING "Warning: Core image elf header is not"
 574                                         "sane\n");
 575                 return -EINVAL;
 576         }
 577
 578         /* Read in all elf headers. */
 579         elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
 580         elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
 581         if (!elfcorebuf)
 582                 return -ENOMEM;
 583         addr = elfcorehdr_addr;
 584         rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
 585         if (rc < 0) {
 586                 kfree(elfcorebuf);
 587                 return rc;
 588         }
 589
 590         /* Merge all PT_NOTE headers into one. */
 591         rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
 592         if (rc) {
 593                 kfree(elfcorebuf);
 594                 return rc;
 595         }
 596         rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
 597                                                                 &vmcore_list);
 598         if (rc) {
 599                 kfree(elfcorebuf);
 600                 return rc;
 601         }
 602         set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list);
 603         return 0;
 604 }
 605
 606 static int __init parse_crash_elf_headers(void)
 607 {
 608         unsigned char e_ident[EI_NIDENT];
 609         u64 addr;
 610         int rc=0;
 611
 612         addr = elfcorehdr_addr;
 613         rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0);
 614         if (rc < 0)
 615                 return rc;
 616         if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
 617                 printk(KERN_WARNING "Warning: Core image elf header"
 618                                         " not found\n");
 619                 return -EINVAL;
 620         }
 621
 622         if (e_ident[EI_CLASS] == ELFCLASS64) {
 623                 rc = parse_crash_elf64_headers();
 624                 if (rc)
 625                         return rc;
 626
 627                 /* Determine vmcore size. */
 628                 vmcore_size = get_vmcore_size_elf64(elfcorebuf);
 629         } else if (e_ident[EI_CLASS] == ELFCLASS32) {
 630                 rc = parse_crash_elf32_headers();
 631                 if (rc)
 632                         return rc;
 633
 634                 /* Determine vmcore size. */
 635                 vmcore_size = get_vmcore_size_elf32(elfcorebuf);
 636         } else {
 637                 printk(KERN_WARNING "Warning: Core image elf header is not"
 638                                         " sane\n");
 639                 return -EINVAL;
 640         }
 641         return 0;
 642 }
 643
 644 /* Init function for vmcore module. */
 645 static int __init vmcore_init(void)
 646 {
 647         int rc = 0;
 648
 649         /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
 650         if (!(elfcorehdr_addr < ELFCORE_ADDR_MAX))
 651                 return rc;
 652         rc = parse_crash_elf_headers();
 653         if (rc) {
 654                 printk(KERN_WARNING "Kdump: vmcore not initialized\n");
 655                 return rc;
 656         }
 657
 658         /* Initialize /proc/vmcore size if proc is already up. */
 659         if (proc_vmcore)
 660                 proc_vmcore->size = vmcore_size;
 661         return 0;
 662 }
 663 module_init(vmcore_init)