Btrfs: check file pointer in btrfs_sync_file
[linux-2.6] / 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 static struct proc_dir_entry *proc_vmcore = NULL;
36
37 /* Reads a page from the oldmem device from given offset. */
38 static ssize_t read_from_oldmem(char *buf, size_t count,
39                                 u64 *ppos, int userbuf)
40 {
41         unsigned long pfn, offset;
42         size_t nr_bytes;
43         ssize_t read = 0, tmp;
44
45         if (!count)
46                 return 0;
47
48         offset = (unsigned long)(*ppos % PAGE_SIZE);
49         pfn = (unsigned long)(*ppos / PAGE_SIZE);
50
51         do {
52                 if (count > (PAGE_SIZE - offset))
53                         nr_bytes = PAGE_SIZE - offset;
54                 else
55                         nr_bytes = count;
56
57                 tmp = copy_oldmem_page(pfn, buf, nr_bytes, offset, userbuf);
58                 if (tmp < 0)
59                         return tmp;
60                 *ppos += nr_bytes;
61                 count -= nr_bytes;
62                 buf += nr_bytes;
63                 read += nr_bytes;
64                 ++pfn;
65                 offset = 0;
66         } while (count);
67
68         return read;
69 }
70
71 /* Maps vmcore file offset to respective physical address in memroy. */
72 static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list,
73                                         struct vmcore **m_ptr)
74 {
75         struct vmcore *m;
76         u64 paddr;
77
78         list_for_each_entry(m, vc_list, list) {
79                 u64 start, end;
80                 start = m->offset;
81                 end = m->offset + m->size - 1;
82                 if (offset >= start && offset <= end) {
83                         paddr = m->paddr + offset - start;
84                         *m_ptr = m;
85                         return paddr;
86                 }
87         }
88         *m_ptr = NULL;
89         return 0;
90 }
91
92 /* Read from the ELF header and then the crash dump. On error, negative value is
93  * returned otherwise number of bytes read are returned.
94  */
95 static ssize_t read_vmcore(struct file *file, char __user *buffer,
96                                 size_t buflen, loff_t *fpos)
97 {
98         ssize_t acc = 0, tmp;
99         size_t tsz;
100         u64 start, nr_bytes;
101         struct vmcore *curr_m = NULL;
102
103         if (buflen == 0 || *fpos >= vmcore_size)
104                 return 0;
105
106         /* trim buflen to not go beyond EOF */
107         if (buflen > vmcore_size - *fpos)
108                 buflen = vmcore_size - *fpos;
109
110         /* Read ELF core header */
111         if (*fpos < elfcorebuf_sz) {
112                 tsz = elfcorebuf_sz - *fpos;
113                 if (buflen < tsz)
114                         tsz = buflen;
115                 if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
116                         return -EFAULT;
117                 buflen -= tsz;
118                 *fpos += tsz;
119                 buffer += tsz;
120                 acc += tsz;
121
122                 /* leave now if filled buffer already */
123                 if (buflen == 0)
124                         return acc;
125         }
126
127         start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m);
128         if (!curr_m)
129                 return -EINVAL;
130         if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
131                 tsz = buflen;
132
133         /* Calculate left bytes in current memory segment. */
134         nr_bytes = (curr_m->size - (start - curr_m->paddr));
135         if (tsz > nr_bytes)
136                 tsz = nr_bytes;
137
138         while (buflen) {
139                 tmp = read_from_oldmem(buffer, tsz, &start, 1);
140                 if (tmp < 0)
141                         return tmp;
142                 buflen -= tsz;
143                 *fpos += tsz;
144                 buffer += tsz;
145                 acc += tsz;
146                 if (start >= (curr_m->paddr + curr_m->size)) {
147                         if (curr_m->list.next == &vmcore_list)
148                                 return acc;     /*EOF*/
149                         curr_m = list_entry(curr_m->list.next,
150                                                 struct vmcore, list);
151                         start = curr_m->paddr;
152                 }
153                 if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
154                         tsz = buflen;
155                 /* Calculate left bytes in current memory segment. */
156                 nr_bytes = (curr_m->size - (start - curr_m->paddr));
157                 if (tsz > nr_bytes)
158                         tsz = nr_bytes;
159         }
160         return acc;
161 }
162
163 static const struct file_operations proc_vmcore_operations = {
164         .read           = read_vmcore,
165 };
166
167 static struct vmcore* __init get_new_element(void)
168 {
169         struct vmcore *p;
170
171         p = kmalloc(sizeof(*p), GFP_KERNEL);
172         if (p)
173                 memset(p, 0, sizeof(*p));
174         return p;
175 }
176
177 static u64 __init get_vmcore_size_elf64(char *elfptr)
178 {
179         int i;
180         u64 size;
181         Elf64_Ehdr *ehdr_ptr;
182         Elf64_Phdr *phdr_ptr;
183
184         ehdr_ptr = (Elf64_Ehdr *)elfptr;
185         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
186         size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr));
187         for (i = 0; i < ehdr_ptr->e_phnum; i++) {
188                 size += phdr_ptr->p_memsz;
189                 phdr_ptr++;
190         }
191         return size;
192 }
193
194 static u64 __init get_vmcore_size_elf32(char *elfptr)
195 {
196         int i;
197         u64 size;
198         Elf32_Ehdr *ehdr_ptr;
199         Elf32_Phdr *phdr_ptr;
200
201         ehdr_ptr = (Elf32_Ehdr *)elfptr;
202         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
203         size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
204         for (i = 0; i < ehdr_ptr->e_phnum; i++) {
205                 size += phdr_ptr->p_memsz;
206                 phdr_ptr++;
207         }
208         return size;
209 }
210
211 /* Merges all the PT_NOTE headers into one. */
212 static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
213                                                 struct list_head *vc_list)
214 {
215         int i, nr_ptnote=0, rc=0;
216         char *tmp;
217         Elf64_Ehdr *ehdr_ptr;
218         Elf64_Phdr phdr, *phdr_ptr;
219         Elf64_Nhdr *nhdr_ptr;
220         u64 phdr_sz = 0, note_off;
221
222         ehdr_ptr = (Elf64_Ehdr *)elfptr;
223         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
224         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
225                 int j;
226                 void *notes_section;
227                 struct vmcore *new;
228                 u64 offset, max_sz, sz, real_sz = 0;
229                 if (phdr_ptr->p_type != PT_NOTE)
230                         continue;
231                 nr_ptnote++;
232                 max_sz = phdr_ptr->p_memsz;
233                 offset = phdr_ptr->p_offset;
234                 notes_section = kmalloc(max_sz, GFP_KERNEL);
235                 if (!notes_section)
236                         return -ENOMEM;
237                 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
238                 if (rc < 0) {
239                         kfree(notes_section);
240                         return rc;
241                 }
242                 nhdr_ptr = notes_section;
243                 for (j = 0; j < max_sz; j += sz) {
244                         if (nhdr_ptr->n_namesz == 0)
245                                 break;
246                         sz = sizeof(Elf64_Nhdr) +
247                                 ((nhdr_ptr->n_namesz + 3) & ~3) +
248                                 ((nhdr_ptr->n_descsz + 3) & ~3);
249                         real_sz += sz;
250                         nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
251                 }
252
253                 /* Add this contiguous chunk of notes section to vmcore list.*/
254                 new = get_new_element();
255                 if (!new) {
256                         kfree(notes_section);
257                         return -ENOMEM;
258                 }
259                 new->paddr = phdr_ptr->p_offset;
260                 new->size = real_sz;
261                 list_add_tail(&new->list, vc_list);
262                 phdr_sz += real_sz;
263                 kfree(notes_section);
264         }
265
266         /* Prepare merged PT_NOTE program header. */
267         phdr.p_type    = PT_NOTE;
268         phdr.p_flags   = 0;
269         note_off = sizeof(Elf64_Ehdr) +
270                         (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
271         phdr.p_offset  = note_off;
272         phdr.p_vaddr   = phdr.p_paddr = 0;
273         phdr.p_filesz  = phdr.p_memsz = phdr_sz;
274         phdr.p_align   = 0;
275
276         /* Add merged PT_NOTE program header*/
277         tmp = elfptr + sizeof(Elf64_Ehdr);
278         memcpy(tmp, &phdr, sizeof(phdr));
279         tmp += sizeof(phdr);
280
281         /* Remove unwanted PT_NOTE program headers. */
282         i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
283         *elfsz = *elfsz - i;
284         memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
285
286         /* Modify e_phnum to reflect merged headers. */
287         ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
288
289         return 0;
290 }
291
292 /* Merges all the PT_NOTE headers into one. */
293 static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
294                                                 struct list_head *vc_list)
295 {
296         int i, nr_ptnote=0, rc=0;
297         char *tmp;
298         Elf32_Ehdr *ehdr_ptr;
299         Elf32_Phdr phdr, *phdr_ptr;
300         Elf32_Nhdr *nhdr_ptr;
301         u64 phdr_sz = 0, note_off;
302
303         ehdr_ptr = (Elf32_Ehdr *)elfptr;
304         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
305         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
306                 int j;
307                 void *notes_section;
308                 struct vmcore *new;
309                 u64 offset, max_sz, sz, real_sz = 0;
310                 if (phdr_ptr->p_type != PT_NOTE)
311                         continue;
312                 nr_ptnote++;
313                 max_sz = phdr_ptr->p_memsz;
314                 offset = phdr_ptr->p_offset;
315                 notes_section = kmalloc(max_sz, GFP_KERNEL);
316                 if (!notes_section)
317                         return -ENOMEM;
318                 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
319                 if (rc < 0) {
320                         kfree(notes_section);
321                         return rc;
322                 }
323                 nhdr_ptr = notes_section;
324                 for (j = 0; j < max_sz; j += sz) {
325                         if (nhdr_ptr->n_namesz == 0)
326                                 break;
327                         sz = sizeof(Elf32_Nhdr) +
328                                 ((nhdr_ptr->n_namesz + 3) & ~3) +
329                                 ((nhdr_ptr->n_descsz + 3) & ~3);
330                         real_sz += sz;
331                         nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
332                 }
333
334                 /* Add this contiguous chunk of notes section to vmcore list.*/
335                 new = get_new_element();
336                 if (!new) {
337                         kfree(notes_section);
338                         return -ENOMEM;
339                 }
340                 new->paddr = phdr_ptr->p_offset;
341                 new->size = real_sz;
342                 list_add_tail(&new->list, vc_list);
343                 phdr_sz += real_sz;
344                 kfree(notes_section);
345         }
346
347         /* Prepare merged PT_NOTE program header. */
348         phdr.p_type    = PT_NOTE;
349         phdr.p_flags   = 0;
350         note_off = sizeof(Elf32_Ehdr) +
351                         (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
352         phdr.p_offset  = note_off;
353         phdr.p_vaddr   = phdr.p_paddr = 0;
354         phdr.p_filesz  = phdr.p_memsz = phdr_sz;
355         phdr.p_align   = 0;
356
357         /* Add merged PT_NOTE program header*/
358         tmp = elfptr + sizeof(Elf32_Ehdr);
359         memcpy(tmp, &phdr, sizeof(phdr));
360         tmp += sizeof(phdr);
361
362         /* Remove unwanted PT_NOTE program headers. */
363         i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
364         *elfsz = *elfsz - i;
365         memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
366
367         /* Modify e_phnum to reflect merged headers. */
368         ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
369
370         return 0;
371 }
372
373 /* Add memory chunks represented by program headers to vmcore list. Also update
374  * the new offset fields of exported program headers. */
375 static int __init process_ptload_program_headers_elf64(char *elfptr,
376                                                 size_t elfsz,
377                                                 struct list_head *vc_list)
378 {
379         int i;
380         Elf64_Ehdr *ehdr_ptr;
381         Elf64_Phdr *phdr_ptr;
382         loff_t vmcore_off;
383         struct vmcore *new;
384
385         ehdr_ptr = (Elf64_Ehdr *)elfptr;
386         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
387
388         /* First program header is PT_NOTE header. */
389         vmcore_off = sizeof(Elf64_Ehdr) +
390                         (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
391                         phdr_ptr->p_memsz; /* Note sections */
392
393         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
394                 if (phdr_ptr->p_type != PT_LOAD)
395                         continue;
396
397                 /* Add this contiguous chunk of memory to vmcore list.*/
398                 new = get_new_element();
399                 if (!new)
400                         return -ENOMEM;
401                 new->paddr = phdr_ptr->p_offset;
402                 new->size = phdr_ptr->p_memsz;
403                 list_add_tail(&new->list, vc_list);
404
405                 /* Update the program header offset. */
406                 phdr_ptr->p_offset = vmcore_off;
407                 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
408         }
409         return 0;
410 }
411
412 static int __init process_ptload_program_headers_elf32(char *elfptr,
413                                                 size_t elfsz,
414                                                 struct list_head *vc_list)
415 {
416         int i;
417         Elf32_Ehdr *ehdr_ptr;
418         Elf32_Phdr *phdr_ptr;
419         loff_t vmcore_off;
420         struct vmcore *new;
421
422         ehdr_ptr = (Elf32_Ehdr *)elfptr;
423         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
424
425         /* First program header is PT_NOTE header. */
426         vmcore_off = sizeof(Elf32_Ehdr) +
427                         (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
428                         phdr_ptr->p_memsz; /* Note sections */
429
430         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
431                 if (phdr_ptr->p_type != PT_LOAD)
432                         continue;
433
434                 /* Add this contiguous chunk of memory to vmcore list.*/
435                 new = get_new_element();
436                 if (!new)
437                         return -ENOMEM;
438                 new->paddr = phdr_ptr->p_offset;
439                 new->size = phdr_ptr->p_memsz;
440                 list_add_tail(&new->list, vc_list);
441
442                 /* Update the program header offset */
443                 phdr_ptr->p_offset = vmcore_off;
444                 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
445         }
446         return 0;
447 }
448
449 /* Sets offset fields of vmcore elements. */
450 static void __init set_vmcore_list_offsets_elf64(char *elfptr,
451                                                 struct list_head *vc_list)
452 {
453         loff_t vmcore_off;
454         Elf64_Ehdr *ehdr_ptr;
455         struct vmcore *m;
456
457         ehdr_ptr = (Elf64_Ehdr *)elfptr;
458
459         /* Skip Elf header and program headers. */
460         vmcore_off = sizeof(Elf64_Ehdr) +
461                         (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr);
462
463         list_for_each_entry(m, vc_list, list) {
464                 m->offset = vmcore_off;
465                 vmcore_off += m->size;
466         }
467 }
468
469 /* Sets offset fields of vmcore elements. */
470 static void __init set_vmcore_list_offsets_elf32(char *elfptr,
471                                                 struct list_head *vc_list)
472 {
473         loff_t vmcore_off;
474         Elf32_Ehdr *ehdr_ptr;
475         struct vmcore *m;
476
477         ehdr_ptr = (Elf32_Ehdr *)elfptr;
478
479         /* Skip Elf header and program headers. */
480         vmcore_off = sizeof(Elf32_Ehdr) +
481                         (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);
482
483         list_for_each_entry(m, vc_list, list) {
484                 m->offset = vmcore_off;
485                 vmcore_off += m->size;
486         }
487 }
488
489 static int __init parse_crash_elf64_headers(void)
490 {
491         int rc=0;
492         Elf64_Ehdr ehdr;
493         u64 addr;
494
495         addr = elfcorehdr_addr;
496
497         /* Read Elf header */
498         rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0);
499         if (rc < 0)
500                 return rc;
501
502         /* Do some basic Verification. */
503         if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
504                 (ehdr.e_type != ET_CORE) ||
505                 !vmcore_elf_check_arch(&ehdr) ||
506                 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
507                 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
508                 ehdr.e_version != EV_CURRENT ||
509                 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
510                 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
511                 ehdr.e_phnum == 0) {
512                 printk(KERN_WARNING "Warning: Core image elf header is not"
513                                         "sane\n");
514                 return -EINVAL;
515         }
516
517         /* Read in all elf headers. */
518         elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr);
519         elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
520         if (!elfcorebuf)
521                 return -ENOMEM;
522         addr = elfcorehdr_addr;
523         rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
524         if (rc < 0) {
525                 kfree(elfcorebuf);
526                 return rc;
527         }
528
529         /* Merge all PT_NOTE headers into one. */
530         rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
531         if (rc) {
532                 kfree(elfcorebuf);
533                 return rc;
534         }
535         rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
536                                                         &vmcore_list);
537         if (rc) {
538                 kfree(elfcorebuf);
539                 return rc;
540         }
541         set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list);
542         return 0;
543 }
544
545 static int __init parse_crash_elf32_headers(void)
546 {
547         int rc=0;
548         Elf32_Ehdr ehdr;
549         u64 addr;
550
551         addr = elfcorehdr_addr;
552
553         /* Read Elf header */
554         rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
555         if (rc < 0)
556                 return rc;
557
558         /* Do some basic Verification. */
559         if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
560                 (ehdr.e_type != ET_CORE) ||
561                 !elf_check_arch(&ehdr) ||
562                 ehdr.e_ident[EI_CLASS] != ELFCLASS32||
563                 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
564                 ehdr.e_version != EV_CURRENT ||
565                 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
566                 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
567                 ehdr.e_phnum == 0) {
568                 printk(KERN_WARNING "Warning: Core image elf header is not"
569                                         "sane\n");
570                 return -EINVAL;
571         }
572
573         /* Read in all elf headers. */
574         elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
575         elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
576         if (!elfcorebuf)
577                 return -ENOMEM;
578         addr = elfcorehdr_addr;
579         rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
580         if (rc < 0) {
581                 kfree(elfcorebuf);
582                 return rc;
583         }
584
585         /* Merge all PT_NOTE headers into one. */
586         rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
587         if (rc) {
588                 kfree(elfcorebuf);
589                 return rc;
590         }
591         rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
592                                                                 &vmcore_list);
593         if (rc) {
594                 kfree(elfcorebuf);
595                 return rc;
596         }
597         set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list);
598         return 0;
599 }
600
601 static int __init parse_crash_elf_headers(void)
602 {
603         unsigned char e_ident[EI_NIDENT];
604         u64 addr;
605         int rc=0;
606
607         addr = elfcorehdr_addr;
608         rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0);
609         if (rc < 0)
610                 return rc;
611         if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
612                 printk(KERN_WARNING "Warning: Core image elf header"
613                                         " not found\n");
614                 return -EINVAL;
615         }
616
617         if (e_ident[EI_CLASS] == ELFCLASS64) {
618                 rc = parse_crash_elf64_headers();
619                 if (rc)
620                         return rc;
621
622                 /* Determine vmcore size. */
623                 vmcore_size = get_vmcore_size_elf64(elfcorebuf);
624         } else if (e_ident[EI_CLASS] == ELFCLASS32) {
625                 rc = parse_crash_elf32_headers();
626                 if (rc)
627                         return rc;
628
629                 /* Determine vmcore size. */
630                 vmcore_size = get_vmcore_size_elf32(elfcorebuf);
631         } else {
632                 printk(KERN_WARNING "Warning: Core image elf header is not"
633                                         " sane\n");
634                 return -EINVAL;
635         }
636         return 0;
637 }
638
639 /* Init function for vmcore module. */
640 static int __init vmcore_init(void)
641 {
642         int rc = 0;
643
644         /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
645         if (!(is_vmcore_usable()))
646                 return rc;
647         rc = parse_crash_elf_headers();
648         if (rc) {
649                 printk(KERN_WARNING "Kdump: vmcore not initialized\n");
650                 return rc;
651         }
652
653         proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
654         if (proc_vmcore)
655                 proc_vmcore->size = vmcore_size;
656         return 0;
657 }
658 module_init(vmcore_init)