74802bc5ded95e09d510bcadfba94167e1390bc2
[linux-2.6.git] / 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/slab.h>
16 #include <linux/highmem.h>
17 #include <linux/bootmem.h>
18 #include <linux/init.h>
19 #include <linux/crash_dump.h>
20 #include <linux/list.h>
21 #include <asm/uaccess.h>
22 #include <asm/io.h>
23
24 /* List representing chunks of contiguous memory areas and their offsets in
25  * vmcore file.
26  */
27 static LIST_HEAD(vmcore_list);
28
29 /* Stores the pointer to the buffer containing kernel elf core headers. */
30 static char *elfcorebuf;
31 static size_t elfcorebuf_sz;
32
33 /* Total size of vmcore file. */
34 static u64 vmcore_size;
35
36 static struct proc_dir_entry *proc_vmcore = NULL;
37
38 /* Reads a page from the oldmem device from given offset. */
39 static ssize_t read_from_oldmem(char *buf, size_t count,
40                                 u64 *ppos, int userbuf)
41 {
42         unsigned long pfn, offset;
43         size_t nr_bytes;
44         ssize_t read = 0, tmp;
45
46         if (!count)
47                 return 0;
48
49         offset = (unsigned long)(*ppos % PAGE_SIZE);
50         pfn = (unsigned long)(*ppos / PAGE_SIZE);
51
52         do {
53                 if (count > (PAGE_SIZE - offset))
54                         nr_bytes = PAGE_SIZE - offset;
55                 else
56                         nr_bytes = count;
57
58                 tmp = copy_oldmem_page(pfn, buf, nr_bytes, offset, userbuf);
59                 if (tmp < 0)
60                         return tmp;
61                 *ppos += nr_bytes;
62                 count -= nr_bytes;
63                 buf += nr_bytes;
64                 read += nr_bytes;
65                 ++pfn;
66                 offset = 0;
67         } while (count);
68
69         return read;
70 }
71
72 /* Maps vmcore file offset to respective physical address in memroy. */
73 static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list,
74                                         struct vmcore **m_ptr)
75 {
76         struct vmcore *m;
77         u64 paddr;
78
79         list_for_each_entry(m, vc_list, list) {
80                 u64 start, end;
81                 start = m->offset;
82                 end = m->offset + m->size - 1;
83                 if (offset >= start && offset <= end) {
84                         paddr = m->paddr + offset - start;
85                         *m_ptr = m;
86                         return paddr;
87                 }
88         }
89         *m_ptr = NULL;
90         return 0;
91 }
92
93 /* Read from the ELF header and then the crash dump. On error, negative value is
94  * returned otherwise number of bytes read are returned.
95  */
96 static ssize_t read_vmcore(struct file *file, char __user *buffer,
97                                 size_t buflen, loff_t *fpos)
98 {
99         ssize_t acc = 0, tmp;
100         size_t tsz;
101         u64 start, nr_bytes;
102         struct vmcore *curr_m = NULL;
103
104         if (buflen == 0 || *fpos >= vmcore_size)
105                 return 0;
106
107         /* trim buflen to not go beyond EOF */
108         if (buflen > vmcore_size - *fpos)
109                 buflen = vmcore_size - *fpos;
110
111         /* Read ELF core header */
112         if (*fpos < elfcorebuf_sz) {
113                 tsz = elfcorebuf_sz - *fpos;
114                 if (buflen < tsz)
115                         tsz = buflen;
116                 if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
117                         return -EFAULT;
118                 buflen -= tsz;
119                 *fpos += tsz;
120                 buffer += tsz;
121                 acc += tsz;
122
123                 /* leave now if filled buffer already */
124                 if (buflen == 0)
125                         return acc;
126         }
127
128         start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m);
129         if (!curr_m)
130                 return -EINVAL;
131         if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
132                 tsz = buflen;
133
134         /* Calculate left bytes in current memory segment. */
135         nr_bytes = (curr_m->size - (start - curr_m->paddr));
136         if (tsz > nr_bytes)
137                 tsz = nr_bytes;
138
139         while (buflen) {
140                 tmp = read_from_oldmem(buffer, tsz, &start, 1);
141                 if (tmp < 0)
142                         return tmp;
143                 buflen -= tsz;
144                 *fpos += tsz;
145                 buffer += tsz;
146                 acc += tsz;
147                 if (start >= (curr_m->paddr + curr_m->size)) {
148                         if (curr_m->list.next == &vmcore_list)
149                                 return acc;     /*EOF*/
150                         curr_m = list_entry(curr_m->list.next,
151                                                 struct vmcore, list);
152                         start = curr_m->paddr;
153                 }
154                 if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
155                         tsz = buflen;
156                 /* Calculate left bytes in current memory segment. */
157                 nr_bytes = (curr_m->size - (start - curr_m->paddr));
158                 if (tsz > nr_bytes)
159                         tsz = nr_bytes;
160         }
161         return acc;
162 }
163
164 static const struct file_operations proc_vmcore_operations = {
165         .read           = read_vmcore,
166         .llseek         = default_llseek,
167 };
168
169 static struct vmcore* __init get_new_element(void)
170 {
171         return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
172 }
173
174 static u64 __init get_vmcore_size_elf64(char *elfptr)
175 {
176         int i;
177         u64 size;
178         Elf64_Ehdr *ehdr_ptr;
179         Elf64_Phdr *phdr_ptr;
180
181         ehdr_ptr = (Elf64_Ehdr *)elfptr;
182         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
183         size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr));
184         for (i = 0; i < ehdr_ptr->e_phnum; i++) {
185                 size += phdr_ptr->p_memsz;
186                 phdr_ptr++;
187         }
188         return size;
189 }
190
191 static u64 __init get_vmcore_size_elf32(char *elfptr)
192 {
193         int i;
194         u64 size;
195         Elf32_Ehdr *ehdr_ptr;
196         Elf32_Phdr *phdr_ptr;
197
198         ehdr_ptr = (Elf32_Ehdr *)elfptr;
199         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
200         size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
201         for (i = 0; i < ehdr_ptr->e_phnum; i++) {
202                 size += phdr_ptr->p_memsz;
203                 phdr_ptr++;
204         }
205         return size;
206 }
207
208 /* Merges all the PT_NOTE headers into one. */
209 static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
210                                                 struct list_head *vc_list)
211 {
212         int i, nr_ptnote=0, rc=0;
213         char *tmp;
214         Elf64_Ehdr *ehdr_ptr;
215         Elf64_Phdr phdr, *phdr_ptr;
216         Elf64_Nhdr *nhdr_ptr;
217         u64 phdr_sz = 0, note_off;
218
219         ehdr_ptr = (Elf64_Ehdr *)elfptr;
220         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
221         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
222                 int j;
223                 void *notes_section;
224                 struct vmcore *new;
225                 u64 offset, max_sz, sz, real_sz = 0;
226                 if (phdr_ptr->p_type != PT_NOTE)
227                         continue;
228                 nr_ptnote++;
229                 max_sz = phdr_ptr->p_memsz;
230                 offset = phdr_ptr->p_offset;
231                 notes_section = kmalloc(max_sz, GFP_KERNEL);
232                 if (!notes_section)
233                         return -ENOMEM;
234                 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
235                 if (rc < 0) {
236                         kfree(notes_section);
237                         return rc;
238                 }
239                 nhdr_ptr = notes_section;
240                 for (j = 0; j < max_sz; j += sz) {
241                         if (nhdr_ptr->n_namesz == 0)
242                                 break;
243                         sz = sizeof(Elf64_Nhdr) +
244                                 ((nhdr_ptr->n_namesz + 3) & ~3) +
245                                 ((nhdr_ptr->n_descsz + 3) & ~3);
246                         real_sz += sz;
247                         nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
248                 }
249
250                 /* Add this contiguous chunk of notes section to vmcore list.*/
251                 new = get_new_element();
252                 if (!new) {
253                         kfree(notes_section);
254                         return -ENOMEM;
255                 }
256                 new->paddr = phdr_ptr->p_offset;
257                 new->size = real_sz;
258                 list_add_tail(&new->list, vc_list);
259                 phdr_sz += real_sz;
260                 kfree(notes_section);
261         }
262
263         /* Prepare merged PT_NOTE program header. */
264         phdr.p_type    = PT_NOTE;
265         phdr.p_flags   = 0;
266         note_off = sizeof(Elf64_Ehdr) +
267                         (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
268         phdr.p_offset  = note_off;
269         phdr.p_vaddr   = phdr.p_paddr = 0;
270         phdr.p_filesz  = phdr.p_memsz = phdr_sz;
271         phdr.p_align   = 0;
272
273         /* Add merged PT_NOTE program header*/
274         tmp = elfptr + sizeof(Elf64_Ehdr);
275         memcpy(tmp, &phdr, sizeof(phdr));
276         tmp += sizeof(phdr);
277
278         /* Remove unwanted PT_NOTE program headers. */
279         i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
280         *elfsz = *elfsz - i;
281         memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
282
283         /* Modify e_phnum to reflect merged headers. */
284         ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
285
286         return 0;
287 }
288
289 /* Merges all the PT_NOTE headers into one. */
290 static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
291                                                 struct list_head *vc_list)
292 {
293         int i, nr_ptnote=0, rc=0;
294         char *tmp;
295         Elf32_Ehdr *ehdr_ptr;
296         Elf32_Phdr phdr, *phdr_ptr;
297         Elf32_Nhdr *nhdr_ptr;
298         u64 phdr_sz = 0, note_off;
299
300         ehdr_ptr = (Elf32_Ehdr *)elfptr;
301         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
302         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
303                 int j;
304                 void *notes_section;
305                 struct vmcore *new;
306                 u64 offset, max_sz, sz, real_sz = 0;
307                 if (phdr_ptr->p_type != PT_NOTE)
308                         continue;
309                 nr_ptnote++;
310                 max_sz = phdr_ptr->p_memsz;
311                 offset = phdr_ptr->p_offset;
312                 notes_section = kmalloc(max_sz, GFP_KERNEL);
313                 if (!notes_section)
314                         return -ENOMEM;
315                 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
316                 if (rc < 0) {
317                         kfree(notes_section);
318                         return rc;
319                 }
320                 nhdr_ptr = notes_section;
321                 for (j = 0; j < max_sz; j += sz) {
322                         if (nhdr_ptr->n_namesz == 0)
323                                 break;
324                         sz = sizeof(Elf32_Nhdr) +
325                                 ((nhdr_ptr->n_namesz + 3) & ~3) +
326                                 ((nhdr_ptr->n_descsz + 3) & ~3);
327                         real_sz += sz;
328                         nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
329                 }
330
331                 /* Add this contiguous chunk of notes section to vmcore list.*/
332                 new = get_new_element();
333                 if (!new) {
334                         kfree(notes_section);
335                         return -ENOMEM;
336                 }
337                 new->paddr = phdr_ptr->p_offset;
338                 new->size = real_sz;
339                 list_add_tail(&new->list, vc_list);
340                 phdr_sz += real_sz;
341                 kfree(notes_section);
342         }
343
344         /* Prepare merged PT_NOTE program header. */
345         phdr.p_type    = PT_NOTE;
346         phdr.p_flags   = 0;
347         note_off = sizeof(Elf32_Ehdr) +
348                         (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
349         phdr.p_offset  = note_off;
350         phdr.p_vaddr   = phdr.p_paddr = 0;
351         phdr.p_filesz  = phdr.p_memsz = phdr_sz;
352         phdr.p_align   = 0;
353
354         /* Add merged PT_NOTE program header*/
355         tmp = elfptr + sizeof(Elf32_Ehdr);
356         memcpy(tmp, &phdr, sizeof(phdr));
357         tmp += sizeof(phdr);
358
359         /* Remove unwanted PT_NOTE program headers. */
360         i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
361         *elfsz = *elfsz - i;
362         memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
363
364         /* Modify e_phnum to reflect merged headers. */
365         ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
366
367         return 0;
368 }
369
370 /* Add memory chunks represented by program headers to vmcore list. Also update
371  * the new offset fields of exported program headers. */
372 static int __init process_ptload_program_headers_elf64(char *elfptr,
373                                                 size_t elfsz,
374                                                 struct list_head *vc_list)
375 {
376         int i;
377         Elf64_Ehdr *ehdr_ptr;
378         Elf64_Phdr *phdr_ptr;
379         loff_t vmcore_off;
380         struct vmcore *new;
381
382         ehdr_ptr = (Elf64_Ehdr *)elfptr;
383         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
384
385         /* First program header is PT_NOTE header. */
386         vmcore_off = sizeof(Elf64_Ehdr) +
387                         (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
388                         phdr_ptr->p_memsz; /* Note sections */
389
390         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
391                 if (phdr_ptr->p_type != PT_LOAD)
392                         continue;
393
394                 /* Add this contiguous chunk of memory to vmcore list.*/
395                 new = get_new_element();
396                 if (!new)
397                         return -ENOMEM;
398                 new->paddr = phdr_ptr->p_offset;
399                 new->size = phdr_ptr->p_memsz;
400                 list_add_tail(&new->list, vc_list);
401
402                 /* Update the program header offset. */
403                 phdr_ptr->p_offset = vmcore_off;
404                 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
405         }
406         return 0;
407 }
408
409 static int __init process_ptload_program_headers_elf32(char *elfptr,
410                                                 size_t elfsz,
411                                                 struct list_head *vc_list)
412 {
413         int i;
414         Elf32_Ehdr *ehdr_ptr;
415         Elf32_Phdr *phdr_ptr;
416         loff_t vmcore_off;
417         struct vmcore *new;
418
419         ehdr_ptr = (Elf32_Ehdr *)elfptr;
420         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
421
422         /* First program header is PT_NOTE header. */
423         vmcore_off = sizeof(Elf32_Ehdr) +
424                         (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
425                         phdr_ptr->p_memsz; /* Note sections */
426
427         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
428                 if (phdr_ptr->p_type != PT_LOAD)
429                         continue;
430
431                 /* Add this contiguous chunk of memory to vmcore list.*/
432                 new = get_new_element();
433                 if (!new)
434                         return -ENOMEM;
435                 new->paddr = phdr_ptr->p_offset;
436                 new->size = phdr_ptr->p_memsz;
437                 list_add_tail(&new->list, vc_list);
438
439                 /* Update the program header offset */
440                 phdr_ptr->p_offset = vmcore_off;
441                 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
442         }
443         return 0;
444 }
445
446 /* Sets offset fields of vmcore elements. */
447 static void __init set_vmcore_list_offsets_elf64(char *elfptr,
448                                                 struct list_head *vc_list)
449 {
450         loff_t vmcore_off;
451         Elf64_Ehdr *ehdr_ptr;
452         struct vmcore *m;
453
454         ehdr_ptr = (Elf64_Ehdr *)elfptr;
455
456         /* Skip Elf header and program headers. */
457         vmcore_off = sizeof(Elf64_Ehdr) +
458                         (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr);
459
460         list_for_each_entry(m, vc_list, list) {
461                 m->offset = vmcore_off;
462                 vmcore_off += m->size;
463         }
464 }
465
466 /* Sets offset fields of vmcore elements. */
467 static void __init set_vmcore_list_offsets_elf32(char *elfptr,
468                                                 struct list_head *vc_list)
469 {
470         loff_t vmcore_off;
471         Elf32_Ehdr *ehdr_ptr;
472         struct vmcore *m;
473
474         ehdr_ptr = (Elf32_Ehdr *)elfptr;
475
476         /* Skip Elf header and program headers. */
477         vmcore_off = sizeof(Elf32_Ehdr) +
478                         (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);
479
480         list_for_each_entry(m, vc_list, list) {
481                 m->offset = vmcore_off;
482                 vmcore_off += m->size;
483         }
484 }
485
486 static int __init parse_crash_elf64_headers(void)
487 {
488         int rc=0;
489         Elf64_Ehdr ehdr;
490         u64 addr;
491
492         addr = elfcorehdr_addr;
493
494         /* Read Elf header */
495         rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0);
496         if (rc < 0)
497                 return rc;
498
499         /* Do some basic Verification. */
500         if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
501                 (ehdr.e_type != ET_CORE) ||
502                 !vmcore_elf64_check_arch(&ehdr) ||
503                 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
504                 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
505                 ehdr.e_version != EV_CURRENT ||
506                 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
507                 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
508                 ehdr.e_phnum == 0) {
509                 printk(KERN_WARNING "Warning: Core image elf header is not"
510                                         "sane\n");
511                 return -EINVAL;
512         }
513
514         /* Read in all elf headers. */
515         elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr);
516         elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
517         if (!elfcorebuf)
518                 return -ENOMEM;
519         addr = elfcorehdr_addr;
520         rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
521         if (rc < 0) {
522                 kfree(elfcorebuf);
523                 return rc;
524         }
525
526         /* Merge all PT_NOTE headers into one. */
527         rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
528         if (rc) {
529                 kfree(elfcorebuf);
530                 return rc;
531         }
532         rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
533                                                         &vmcore_list);
534         if (rc) {
535                 kfree(elfcorebuf);
536                 return rc;
537         }
538         set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list);
539         return 0;
540 }
541
542 static int __init parse_crash_elf32_headers(void)
543 {
544         int rc=0;
545         Elf32_Ehdr ehdr;
546         u64 addr;
547
548         addr = elfcorehdr_addr;
549
550         /* Read Elf header */
551         rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
552         if (rc < 0)
553                 return rc;
554
555         /* Do some basic Verification. */
556         if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
557                 (ehdr.e_type != ET_CORE) ||
558                 !elf_check_arch(&ehdr) ||
559                 ehdr.e_ident[EI_CLASS] != ELFCLASS32||
560                 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
561                 ehdr.e_version != EV_CURRENT ||
562                 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
563                 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
564                 ehdr.e_phnum == 0) {
565                 printk(KERN_WARNING "Warning: Core image elf header is not"
566                                         "sane\n");
567                 return -EINVAL;
568         }
569
570         /* Read in all elf headers. */
571         elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
572         elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
573         if (!elfcorebuf)
574                 return -ENOMEM;
575         addr = elfcorehdr_addr;
576         rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
577         if (rc < 0) {
578                 kfree(elfcorebuf);
579                 return rc;
580         }
581
582         /* Merge all PT_NOTE headers into one. */
583         rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
584         if (rc) {
585                 kfree(elfcorebuf);
586                 return rc;
587         }
588         rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
589                                                                 &vmcore_list);
590         if (rc) {
591                 kfree(elfcorebuf);
592                 return rc;
593         }
594         set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list);
595         return 0;
596 }
597
598 static int __init parse_crash_elf_headers(void)
599 {
600         unsigned char e_ident[EI_NIDENT];
601         u64 addr;
602         int rc=0;
603
604         addr = elfcorehdr_addr;
605         rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0);
606         if (rc < 0)
607                 return rc;
608         if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
609                 printk(KERN_WARNING "Warning: Core image elf header"
610                                         " not found\n");
611                 return -EINVAL;
612         }
613
614         if (e_ident[EI_CLASS] == ELFCLASS64) {
615                 rc = parse_crash_elf64_headers();
616                 if (rc)
617                         return rc;
618
619                 /* Determine vmcore size. */
620                 vmcore_size = get_vmcore_size_elf64(elfcorebuf);
621         } else if (e_ident[EI_CLASS] == ELFCLASS32) {
622                 rc = parse_crash_elf32_headers();
623                 if (rc)
624                         return rc;
625
626                 /* Determine vmcore size. */
627                 vmcore_size = get_vmcore_size_elf32(elfcorebuf);
628         } else {
629                 printk(KERN_WARNING "Warning: Core image elf header is not"
630                                         " sane\n");
631                 return -EINVAL;
632         }
633         return 0;
634 }
635
636 /* Init function for vmcore module. */
637 static int __init vmcore_init(void)
638 {
639         int rc = 0;
640
641         /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
642         if (!(is_vmcore_usable()))
643                 return rc;
644         rc = parse_crash_elf_headers();
645         if (rc) {
646                 printk(KERN_WARNING "Kdump: vmcore not initialized\n");
647                 return rc;
648         }
649
650         proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
651         if (proc_vmcore)
652                 proc_vmcore->size = vmcore_size;
653         return 0;
654 }
655 module_init(vmcore_init)