841368b87a29dbb89c68c4539b6203a7e0501905
[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/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)