linux/fs/proc/vmcore.c
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   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/export.h>
  16#include <linux/slab.h>
  17#include <linux/highmem.h>
  18#include <linux/bootmem.h>
  19#include <linux/init.h>
  20#include <linux/crash_dump.h>
  21#include <linux/list.h>
  22#include <asm/uaccess.h>
  23#include <asm/io.h>
  24
  25/* List representing chunks of contiguous memory areas and their offsets in
  26 * vmcore file.
  27 */
  28static LIST_HEAD(vmcore_list);
  29
  30/* Stores the pointer to the buffer containing kernel elf core headers. */
  31static char *elfcorebuf;
  32static size_t elfcorebuf_sz;
  33
  34/* Total size of vmcore file. */
  35static u64 vmcore_size;
  36
  37static struct proc_dir_entry *proc_vmcore = NULL;
  38
  39/*
  40 * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
  41 * The called function has to take care of module refcounting.
  42 */
  43static int (*oldmem_pfn_is_ram)(unsigned long pfn);
  44
  45int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn))
  46{
  47        if (oldmem_pfn_is_ram)
  48                return -EBUSY;
  49        oldmem_pfn_is_ram = fn;
  50        return 0;
  51}
  52EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram);
  53
  54void unregister_oldmem_pfn_is_ram(void)
  55{
  56        oldmem_pfn_is_ram = NULL;
  57        wmb();
  58}
  59EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram);
  60
  61static int pfn_is_ram(unsigned long pfn)
  62{
  63        int (*fn)(unsigned long pfn);
  64        /* pfn is ram unless fn() checks pagetype */
  65        int ret = 1;
  66
  67        /*
  68         * Ask hypervisor if the pfn is really ram.
  69         * A ballooned page contains no data and reading from such a page
  70         * will cause high load in the hypervisor.
  71         */
  72        fn = oldmem_pfn_is_ram;
  73        if (fn)
  74                ret = fn(pfn);
  75
  76        return ret;
  77}
  78
  79/* Reads a page from the oldmem device from given offset. */
  80static ssize_t read_from_oldmem(char *buf, size_t count,
  81                                u64 *ppos, int userbuf)
  82{
  83        unsigned long pfn, offset;
  84        size_t nr_bytes;
  85        ssize_t read = 0, tmp;
  86
  87        if (!count)
  88                return 0;
  89
  90        offset = (unsigned long)(*ppos % PAGE_SIZE);
  91        pfn = (unsigned long)(*ppos / PAGE_SIZE);
  92
  93        do {
  94                if (count > (PAGE_SIZE - offset))
  95                        nr_bytes = PAGE_SIZE - offset;
  96                else
  97                        nr_bytes = count;
  98
  99                /* If pfn is not ram, return zeros for sparse dump files */
 100                if (pfn_is_ram(pfn) == 0)
 101                        memset(buf, 0, nr_bytes);
 102                else {
 103                        tmp = copy_oldmem_page(pfn, buf, nr_bytes,
 104                                                offset, userbuf);
 105                        if (tmp < 0)
 106                                return tmp;
 107                }
 108                *ppos += nr_bytes;
 109                count -= nr_bytes;
 110                buf += nr_bytes;
 111                read += nr_bytes;
 112                ++pfn;
 113                offset = 0;
 114        } while (count);
 115
 116        return read;
 117}
 118
 119/* Maps vmcore file offset to respective physical address in memroy. */
 120static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list,
 121                                        struct vmcore **m_ptr)
 122{
 123        struct vmcore *m;
 124        u64 paddr;
 125
 126        list_for_each_entry(m, vc_list, list) {
 127                u64 start, end;
 128                start = m->offset;
 129                end = m->offset + m->size - 1;
 130                if (offset >= start && offset <= end) {
 131                        paddr = m->paddr + offset - start;
 132                        *m_ptr = m;
 133                        return paddr;
 134                }
 135        }
 136        *m_ptr = NULL;
 137        return 0;
 138}
 139
 140/* Read from the ELF header and then the crash dump. On error, negative value is
 141 * returned otherwise number of bytes read are returned.
 142 */
 143static ssize_t read_vmcore(struct file *file, char __user *buffer,
 144                                size_t buflen, loff_t *fpos)
 145{
 146        ssize_t acc = 0, tmp;
 147        size_t tsz;
 148        u64 start, nr_bytes;
 149        struct vmcore *curr_m = NULL;
 150
 151        if (buflen == 0 || *fpos >= vmcore_size)
 152                return 0;
 153
 154        /* trim buflen to not go beyond EOF */
 155        if (buflen > vmcore_size - *fpos)
 156                buflen = vmcore_size - *fpos;
 157
 158        /* Read ELF core header */
 159        if (*fpos < elfcorebuf_sz) {
 160                tsz = elfcorebuf_sz - *fpos;
 161                if (buflen < tsz)
 162                        tsz = buflen;
 163                if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
 164                        return -EFAULT;
 165                buflen -= tsz;
 166                *fpos += tsz;
 167                buffer += tsz;
 168                acc += tsz;
 169
 170                /* leave now if filled buffer already */
 171                if (buflen == 0)
 172                        return acc;
 173        }
 174
 175        start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m);
 176        if (!curr_m)
 177                return -EINVAL;
 178        if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
 179                tsz = buflen;
 180
 181        /* Calculate left bytes in current memory segment. */
 182        nr_bytes = (curr_m->size - (start - curr_m->paddr));
 183        if (tsz > nr_bytes)
 184                tsz = nr_bytes;
 185
 186        while (buflen) {
 187                tmp = read_from_oldmem(buffer, tsz, &start, 1);
 188                if (tmp < 0)
 189                        return tmp;
 190                buflen -= tsz;
 191                *fpos += tsz;
 192                buffer += tsz;
 193                acc += tsz;
 194                if (start >= (curr_m->paddr + curr_m->size)) {
 195                        if (curr_m->list.next == &vmcore_list)
 196                                return acc;     /*EOF*/
 197                        curr_m = list_entry(curr_m->list.next,
 198                                                struct vmcore, list);
 199                        start = curr_m->paddr;
 200                }
 201                if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
 202                        tsz = buflen;
 203                /* Calculate left bytes in current memory segment. */
 204                nr_bytes = (curr_m->size - (start - curr_m->paddr));
 205                if (tsz > nr_bytes)
 206                        tsz = nr_bytes;
 207        }
 208        return acc;
 209}
 210
 211static const struct file_operations proc_vmcore_operations = {
 212        .read           = read_vmcore,
 213        .llseek         = default_llseek,
 214};
 215
 216static struct vmcore* __init get_new_element(void)
 217{
 218        return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
 219}
 220
 221static u64 __init get_vmcore_size_elf64(char *elfptr)
 222{
 223        int i;
 224        u64 size;
 225        Elf64_Ehdr *ehdr_ptr;
 226        Elf64_Phdr *phdr_ptr;
 227
 228        ehdr_ptr = (Elf64_Ehdr *)elfptr;
 229        phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
 230        size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr));
 231        for (i = 0; i < ehdr_ptr->e_phnum; i++) {
 232                size += phdr_ptr->p_memsz;
 233                phdr_ptr++;
 234        }
 235        return size;
 236}
 237
 238static u64 __init get_vmcore_size_elf32(char *elfptr)
 239{
 240        int i;
 241        u64 size;
 242        Elf32_Ehdr *ehdr_ptr;
 243        Elf32_Phdr *phdr_ptr;
 244
 245        ehdr_ptr = (Elf32_Ehdr *)elfptr;
 246        phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
 247        size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
 248        for (i = 0; i < ehdr_ptr->e_phnum; i++) {
 249                size += phdr_ptr->p_memsz;
 250                phdr_ptr++;
 251        }
 252        return size;
 253}
 254
 255/* Merges all the PT_NOTE headers into one. */
 256static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
 257                                                struct list_head *vc_list)
 258{
 259        int i, nr_ptnote=0, rc=0;
 260        char *tmp;
 261        Elf64_Ehdr *ehdr_ptr;
 262        Elf64_Phdr phdr, *phdr_ptr;
 263        Elf64_Nhdr *nhdr_ptr;
 264        u64 phdr_sz = 0, note_off;
 265
 266        ehdr_ptr = (Elf64_Ehdr *)elfptr;
 267        phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
 268        for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
 269                int j;
 270                void *notes_section;
 271                struct vmcore *new;
 272                u64 offset, max_sz, sz, real_sz = 0;
 273                if (phdr_ptr->p_type != PT_NOTE)
 274                        continue;
 275                nr_ptnote++;
 276                max_sz = phdr_ptr->p_memsz;
 277                offset = phdr_ptr->p_offset;
 278                notes_section = kmalloc(max_sz, GFP_KERNEL);
 279                if (!notes_section)
 280                        return -ENOMEM;
 281                rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
 282                if (rc < 0) {
 283                        kfree(notes_section);
 284                        return rc;
 285                }
 286                nhdr_ptr = notes_section;
 287                for (j = 0; j < max_sz; j += sz) {
 288                        if (nhdr_ptr->n_namesz == 0)
 289                                break;
 290                        sz = sizeof(Elf64_Nhdr) +
 291                                ((nhdr_ptr->n_namesz + 3) & ~3) +
 292                                ((nhdr_ptr->n_descsz + 3) & ~3);
 293                        real_sz += sz;
 294                        nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
 295                }
 296
 297                /* Add this contiguous chunk of notes section to vmcore list.*/
 298                new = get_new_element();
 299                if (!new) {
 300                        kfree(notes_section);
 301                        return -ENOMEM;
 302                }
 303                new->paddr = phdr_ptr->p_offset;
 304                new->size = real_sz;
 305                list_add_tail(&new->list, vc_list);
 306                phdr_sz += real_sz;
 307                kfree(notes_section);
 308        }
 309
 310        /* Prepare merged PT_NOTE program header. */
 311        phdr.p_type    = PT_NOTE;
 312        phdr.p_flags   = 0;
 313        note_off = sizeof(Elf64_Ehdr) +
 314                        (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
 315        phdr.p_offset  = note_off;
 316        phdr.p_vaddr   = phdr.p_paddr = 0;
 317        phdr.p_filesz  = phdr.p_memsz = phdr_sz;
 318        phdr.p_align   = 0;
 319
 320        /* Add merged PT_NOTE program header*/
 321        tmp = elfptr + sizeof(Elf64_Ehdr);
 322        memcpy(tmp, &phdr, sizeof(phdr));
 323        tmp += sizeof(phdr);
 324
 325        /* Remove unwanted PT_NOTE program headers. */
 326        i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
 327        *elfsz = *elfsz - i;
 328        memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
 329
 330        /* Modify e_phnum to reflect merged headers. */
 331        ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
 332
 333        return 0;
 334}
 335
 336/* Merges all the PT_NOTE headers into one. */
 337static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
 338                                                struct list_head *vc_list)
 339{
 340        int i, nr_ptnote=0, rc=0;
 341        char *tmp;
 342        Elf32_Ehdr *ehdr_ptr;
 343        Elf32_Phdr phdr, *phdr_ptr;
 344        Elf32_Nhdr *nhdr_ptr;
 345        u64 phdr_sz = 0, note_off;
 346
 347        ehdr_ptr = (Elf32_Ehdr *)elfptr;
 348        phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
 349        for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
 350                int j;
 351                void *notes_section;
 352                struct vmcore *new;
 353                u64 offset, max_sz, sz, real_sz = 0;
 354                if (phdr_ptr->p_type != PT_NOTE)
 355                        continue;
 356                nr_ptnote++;
 357                max_sz = phdr_ptr->p_memsz;
 358                offset = phdr_ptr->p_offset;
 359                notes_section = kmalloc(max_sz, GFP_KERNEL);
 360                if (!notes_section)
 361                        return -ENOMEM;
 362                rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
 363                if (rc < 0) {
 364                        kfree(notes_section);
 365                        return rc;
 366                }
 367                nhdr_ptr = notes_section;
 368                for (j = 0; j < max_sz; j += sz) {
 369                        if (nhdr_ptr->n_namesz == 0)
 370                                break;
 371                        sz = sizeof(Elf32_Nhdr) +
 372                                ((nhdr_ptr->n_namesz + 3) & ~3) +
 373                                ((nhdr_ptr->n_descsz + 3) & ~3);
 374                        real_sz += sz;
 375                        nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
 376                }
 377
 378                /* Add this contiguous chunk of notes section to vmcore list.*/
 379                new = get_new_element();
 380                if (!new) {
 381                        kfree(notes_section);
 382                        return -ENOMEM;
 383                }
 384                new->paddr = phdr_ptr->p_offset;
 385                new->size = real_sz;
 386                list_add_tail(&new->list, vc_list);
 387                phdr_sz += real_sz;
 388                kfree(notes_section);
 389        }
 390
 391        /* Prepare merged PT_NOTE program header. */
 392        phdr.p_type    = PT_NOTE;
 393        phdr.p_flags   = 0;
 394        note_off = sizeof(Elf32_Ehdr) +
 395                        (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
 396        phdr.p_offset  = note_off;
 397        phdr.p_vaddr   = phdr.p_paddr = 0;
 398        phdr.p_filesz  = phdr.p_memsz = phdr_sz;
 399        phdr.p_align   = 0;
 400
 401        /* Add merged PT_NOTE program header*/
 402        tmp = elfptr + sizeof(Elf32_Ehdr);
 403        memcpy(tmp, &phdr, sizeof(phdr));
 404        tmp += sizeof(phdr);
 405
 406        /* Remove unwanted PT_NOTE program headers. */
 407        i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
 408        *elfsz = *elfsz - i;
 409        memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
 410
 411        /* Modify e_phnum to reflect merged headers. */
 412        ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
 413
 414        return 0;
 415}
 416
 417/* Add memory chunks represented by program headers to vmcore list. Also update
 418 * the new offset fields of exported program headers. */
 419static int __init process_ptload_program_headers_elf64(char *elfptr,
 420                                                size_t elfsz,
 421                                                struct list_head *vc_list)
 422{
 423        int i;
 424        Elf64_Ehdr *ehdr_ptr;
 425        Elf64_Phdr *phdr_ptr;
 426        loff_t vmcore_off;
 427        struct vmcore *new;
 428
 429        ehdr_ptr = (Elf64_Ehdr *)elfptr;
 430        phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
 431
 432        /* First program header is PT_NOTE header. */
 433        vmcore_off = sizeof(Elf64_Ehdr) +
 434                        (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
 435                        phdr_ptr->p_memsz; /* Note sections */
 436
 437        for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
 438                if (phdr_ptr->p_type != PT_LOAD)
 439                        continue;
 440
 441                /* Add this contiguous chunk of memory to vmcore list.*/
 442                new = get_new_element();
 443                if (!new)
 444                        return -ENOMEM;
 445                new->paddr = phdr_ptr->p_offset;
 446                new->size = phdr_ptr->p_memsz;
 447                list_add_tail(&new->list, vc_list);
 448
 449                /* Update the program header offset. */
 450                phdr_ptr->p_offset = vmcore_off;
 451                vmcore_off = vmcore_off + phdr_ptr->p_memsz;
 452        }
 453        return 0;
 454}
 455
 456static int __init process_ptload_program_headers_elf32(char *elfptr,
 457                                                size_t elfsz,
 458                                                struct list_head *vc_list)
 459{
 460        int i;
 461        Elf32_Ehdr *ehdr_ptr;
 462        Elf32_Phdr *phdr_ptr;
 463        loff_t vmcore_off;
 464        struct vmcore *new;
 465
 466        ehdr_ptr = (Elf32_Ehdr *)elfptr;
 467        phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
 468
 469        /* First program header is PT_NOTE header. */
 470        vmcore_off = sizeof(Elf32_Ehdr) +
 471                        (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
 472                        phdr_ptr->p_memsz; /* Note sections */
 473
 474        for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
 475                if (phdr_ptr->p_type != PT_LOAD)
 476                        continue;
 477
 478                /* Add this contiguous chunk of memory to vmcore list.*/
 479                new = get_new_element();
 480                if (!new)
 481                        return -ENOMEM;
 482                new->paddr = phdr_ptr->p_offset;
 483                new->size = phdr_ptr->p_memsz;
 484                list_add_tail(&new->list, vc_list);
 485
 486                /* Update the program header offset */
 487                phdr_ptr->p_offset = vmcore_off;
 488                vmcore_off = vmcore_off + phdr_ptr->p_memsz;
 489        }
 490        return 0;
 491}
 492
 493/* Sets offset fields of vmcore elements. */
 494static void __init set_vmcore_list_offsets_elf64(char *elfptr,
 495                                                struct list_head *vc_list)
 496{
 497        loff_t vmcore_off;
 498        Elf64_Ehdr *ehdr_ptr;
 499        struct vmcore *m;
 500
 501        ehdr_ptr = (Elf64_Ehdr *)elfptr;
 502
 503        /* Skip Elf header and program headers. */
 504        vmcore_off = sizeof(Elf64_Ehdr) +
 505                        (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr);
 506
 507        list_for_each_entry(m, vc_list, list) {
 508                m->offset = vmcore_off;
 509                vmcore_off += m->size;
 510        }
 511}
 512
 513/* Sets offset fields of vmcore elements. */
 514static void __init set_vmcore_list_offsets_elf32(char *elfptr,
 515                                                struct list_head *vc_list)
 516{
 517        loff_t vmcore_off;
 518        Elf32_Ehdr *ehdr_ptr;
 519        struct vmcore *m;
 520
 521        ehdr_ptr = (Elf32_Ehdr *)elfptr;
 522
 523        /* Skip Elf header and program headers. */
 524        vmcore_off = sizeof(Elf32_Ehdr) +
 525                        (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);
 526
 527        list_for_each_entry(m, vc_list, list) {
 528                m->offset = vmcore_off;
 529                vmcore_off += m->size;
 530        }
 531}
 532
 533static int __init parse_crash_elf64_headers(void)
 534{
 535        int rc=0;
 536        Elf64_Ehdr ehdr;
 537        u64 addr;
 538
 539        addr = elfcorehdr_addr;
 540
 541        /* Read Elf header */
 542        rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0);
 543        if (rc < 0)
 544                return rc;
 545
 546        /* Do some basic Verification. */
 547        if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
 548                (ehdr.e_type != ET_CORE) ||
 549                !vmcore_elf64_check_arch(&ehdr) ||
 550                ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
 551                ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
 552                ehdr.e_version != EV_CURRENT ||
 553                ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
 554                ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
 555                ehdr.e_phnum == 0) {
 556                printk(KERN_WARNING "Warning: Core image elf header is not"
 557                                        "sane\n");
 558                return -EINVAL;
 559        }
 560
 561        /* Read in all elf headers. */
 562        elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr);
 563        elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
 564        if (!elfcorebuf)
 565                return -ENOMEM;
 566        addr = elfcorehdr_addr;
 567        rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
 568        if (rc < 0) {
 569                kfree(elfcorebuf);
 570                return rc;
 571        }
 572
 573        /* Merge all PT_NOTE headers into one. */
 574        rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
 575        if (rc) {
 576                kfree(elfcorebuf);
 577                return rc;
 578        }
 579        rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
 580                                                        &vmcore_list);
 581        if (rc) {
 582                kfree(elfcorebuf);
 583                return rc;
 584        }
 585        set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list);
 586        return 0;
 587}
 588
 589static int __init parse_crash_elf32_headers(void)
 590{
 591        int rc=0;
 592        Elf32_Ehdr ehdr;
 593        u64 addr;
 594
 595        addr = elfcorehdr_addr;
 596
 597        /* Read Elf header */
 598        rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
 599        if (rc < 0)
 600                return rc;
 601
 602        /* Do some basic Verification. */
 603        if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
 604                (ehdr.e_type != ET_CORE) ||
 605                !elf_check_arch(&ehdr) ||
 606                ehdr.e_ident[EI_CLASS] != ELFCLASS32||
 607                ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
 608                ehdr.e_version != EV_CURRENT ||
 609                ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
 610                ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
 611                ehdr.e_phnum == 0) {
 612                printk(KERN_WARNING "Warning: Core image elf header is not"
 613                                        "sane\n");
 614                return -EINVAL;
 615        }
 616
 617        /* Read in all elf headers. */
 618        elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
 619        elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
 620        if (!elfcorebuf)
 621                return -ENOMEM;
 622        addr = elfcorehdr_addr;
 623        rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
 624        if (rc < 0) {
 625                kfree(elfcorebuf);
 626                return rc;
 627        }
 628
 629        /* Merge all PT_NOTE headers into one. */
 630        rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
 631        if (rc) {
 632                kfree(elfcorebuf);
 633                return rc;
 634        }
 635        rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
 636                                                                &vmcore_list);
 637        if (rc) {
 638                kfree(elfcorebuf);
 639                return rc;
 640        }
 641        set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list);
 642        return 0;
 643}
 644
 645static int __init parse_crash_elf_headers(void)
 646{
 647        unsigned char e_ident[EI_NIDENT];
 648        u64 addr;
 649        int rc=0;
 650
 651        addr = elfcorehdr_addr;
 652        rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0);
 653        if (rc < 0)
 654                return rc;
 655        if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
 656                printk(KERN_WARNING "Warning: Core image elf header"
 657                                        " not found\n");
 658                return -EINVAL;
 659        }
 660
 661        if (e_ident[EI_CLASS] == ELFCLASS64) {
 662                rc = parse_crash_elf64_headers();
 663                if (rc)
 664                        return rc;
 665
 666                /* Determine vmcore size. */
 667                vmcore_size = get_vmcore_size_elf64(elfcorebuf);
 668        } else if (e_ident[EI_CLASS] == ELFCLASS32) {
 669                rc = parse_crash_elf32_headers();
 670                if (rc)
 671                        return rc;
 672
 673                /* Determine vmcore size. */
 674                vmcore_size = get_vmcore_size_elf32(elfcorebuf);
 675        } else {
 676                printk(KERN_WARNING "Warning: Core image elf header is not"
 677                                        " sane\n");
 678                return -EINVAL;
 679        }
 680        return 0;
 681}
 682
 683/* Init function for vmcore module. */
 684static int __init vmcore_init(void)
 685{
 686        int rc = 0;
 687
 688        /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
 689        if (!(is_vmcore_usable()))
 690                return rc;
 691        rc = parse_crash_elf_headers();
 692        if (rc) {
 693                printk(KERN_WARNING "Kdump: vmcore not initialized\n");
 694                return rc;
 695        }
 696
 697        proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
 698        if (proc_vmcore)
 699                proc_vmcore->size = vmcore_size;
 700        return 0;
 701}
 702module_init(vmcore_init)
 703
 704/* Cleanup function for vmcore module. */
 705void vmcore_cleanup(void)
 706{
 707        struct list_head *pos, *next;
 708
 709        if (proc_vmcore) {
 710                remove_proc_entry(proc_vmcore->name, proc_vmcore->parent);
 711                proc_vmcore = NULL;
 712        }
 713
 714        /* clear the vmcore list. */
 715        list_for_each_safe(pos, next, &vmcore_list) {
 716                struct vmcore *m;
 717
 718                m = list_entry(pos, struct vmcore, list);
 719                list_del(&m->list);
 720                kfree(m);
 721        }
 722        kfree(elfcorebuf);
 723        elfcorebuf = NULL;
 724}
 725EXPORT_SYMBOL_GPL(vmcore_cleanup);
 726
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