Merge branch 'linus' into x86/defconfig
[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 /* 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 static int open_vmcore(struct inode *inode, struct file *filp)
169 {
170         return 0;
171 }
172
173 const struct file_operations proc_vmcore_operations = {
174         .read           = read_vmcore,
175         .open           = open_vmcore,
176 };
177
178 static struct vmcore* __init get_new_element(void)
179 {
180         struct vmcore *p;
181
182         p = kmalloc(sizeof(*p), GFP_KERNEL);
183         if (p)
184                 memset(p, 0, sizeof(*p));
185         return p;
186 }
187
188 static u64 __init get_vmcore_size_elf64(char *elfptr)
189 {
190         int i;
191         u64 size;
192         Elf64_Ehdr *ehdr_ptr;
193         Elf64_Phdr *phdr_ptr;
194
195         ehdr_ptr = (Elf64_Ehdr *)elfptr;
196         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
197         size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr));
198         for (i = 0; i < ehdr_ptr->e_phnum; i++) {
199                 size += phdr_ptr->p_memsz;
200                 phdr_ptr++;
201         }
202         return size;
203 }
204
205 static u64 __init get_vmcore_size_elf32(char *elfptr)
206 {
207         int i;
208         u64 size;
209         Elf32_Ehdr *ehdr_ptr;
210         Elf32_Phdr *phdr_ptr;
211
212         ehdr_ptr = (Elf32_Ehdr *)elfptr;
213         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
214         size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
215         for (i = 0; i < ehdr_ptr->e_phnum; i++) {
216                 size += phdr_ptr->p_memsz;
217                 phdr_ptr++;
218         }
219         return size;
220 }
221
222 /* Merges all the PT_NOTE headers into one. */
223 static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
224                                                 struct list_head *vc_list)
225 {
226         int i, nr_ptnote=0, rc=0;
227         char *tmp;
228         Elf64_Ehdr *ehdr_ptr;
229         Elf64_Phdr phdr, *phdr_ptr;
230         Elf64_Nhdr *nhdr_ptr;
231         u64 phdr_sz = 0, note_off;
232
233         ehdr_ptr = (Elf64_Ehdr *)elfptr;
234         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
235         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
236                 int j;
237                 void *notes_section;
238                 struct vmcore *new;
239                 u64 offset, max_sz, sz, real_sz = 0;
240                 if (phdr_ptr->p_type != PT_NOTE)
241                         continue;
242                 nr_ptnote++;
243                 max_sz = phdr_ptr->p_memsz;
244                 offset = phdr_ptr->p_offset;
245                 notes_section = kmalloc(max_sz, GFP_KERNEL);
246                 if (!notes_section)
247                         return -ENOMEM;
248                 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
249                 if (rc < 0) {
250                         kfree(notes_section);
251                         return rc;
252                 }
253                 nhdr_ptr = notes_section;
254                 for (j = 0; j < max_sz; j += sz) {
255                         if (nhdr_ptr->n_namesz == 0)
256                                 break;
257                         sz = sizeof(Elf64_Nhdr) +
258                                 ((nhdr_ptr->n_namesz + 3) & ~3) +
259                                 ((nhdr_ptr->n_descsz + 3) & ~3);
260                         real_sz += sz;
261                         nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
262                 }
263
264                 /* Add this contiguous chunk of notes section to vmcore list.*/
265                 new = get_new_element();
266                 if (!new) {
267                         kfree(notes_section);
268                         return -ENOMEM;
269                 }
270                 new->paddr = phdr_ptr->p_offset;
271                 new->size = real_sz;
272                 list_add_tail(&new->list, vc_list);
273                 phdr_sz += real_sz;
274                 kfree(notes_section);
275         }
276
277         /* Prepare merged PT_NOTE program header. */
278         phdr.p_type    = PT_NOTE;
279         phdr.p_flags   = 0;
280         note_off = sizeof(Elf64_Ehdr) +
281                         (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
282         phdr.p_offset  = note_off;
283         phdr.p_vaddr   = phdr.p_paddr = 0;
284         phdr.p_filesz  = phdr.p_memsz = phdr_sz;
285         phdr.p_align   = 0;
286
287         /* Add merged PT_NOTE program header*/
288         tmp = elfptr + sizeof(Elf64_Ehdr);
289         memcpy(tmp, &phdr, sizeof(phdr));
290         tmp += sizeof(phdr);
291
292         /* Remove unwanted PT_NOTE program headers. */
293         i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
294         *elfsz = *elfsz - i;
295         memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
296
297         /* Modify e_phnum to reflect merged headers. */
298         ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
299
300         return 0;
301 }
302
303 /* Merges all the PT_NOTE headers into one. */
304 static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
305                                                 struct list_head *vc_list)
306 {
307         int i, nr_ptnote=0, rc=0;
308         char *tmp;
309         Elf32_Ehdr *ehdr_ptr;
310         Elf32_Phdr phdr, *phdr_ptr;
311         Elf32_Nhdr *nhdr_ptr;
312         u64 phdr_sz = 0, note_off;
313
314         ehdr_ptr = (Elf32_Ehdr *)elfptr;
315         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
316         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
317                 int j;
318                 void *notes_section;
319                 struct vmcore *new;
320                 u64 offset, max_sz, sz, real_sz = 0;
321                 if (phdr_ptr->p_type != PT_NOTE)
322                         continue;
323                 nr_ptnote++;
324                 max_sz = phdr_ptr->p_memsz;
325                 offset = phdr_ptr->p_offset;
326                 notes_section = kmalloc(max_sz, GFP_KERNEL);
327                 if (!notes_section)
328                         return -ENOMEM;
329                 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
330                 if (rc < 0) {
331                         kfree(notes_section);
332                         return rc;
333                 }
334                 nhdr_ptr = notes_section;
335                 for (j = 0; j < max_sz; j += sz) {
336                         if (nhdr_ptr->n_namesz == 0)
337                                 break;
338                         sz = sizeof(Elf32_Nhdr) +
339                                 ((nhdr_ptr->n_namesz + 3) & ~3) +
340                                 ((nhdr_ptr->n_descsz + 3) & ~3);
341                         real_sz += sz;
342                         nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
343                 }
344
345                 /* Add this contiguous chunk of notes section to vmcore list.*/
346                 new = get_new_element();
347                 if (!new) {
348                         kfree(notes_section);
349                         return -ENOMEM;
350                 }
351                 new->paddr = phdr_ptr->p_offset;
352                 new->size = real_sz;
353                 list_add_tail(&new->list, vc_list);
354                 phdr_sz += real_sz;
355                 kfree(notes_section);
356         }
357
358         /* Prepare merged PT_NOTE program header. */
359         phdr.p_type    = PT_NOTE;
360         phdr.p_flags   = 0;
361         note_off = sizeof(Elf32_Ehdr) +
362                         (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
363         phdr.p_offset  = note_off;
364         phdr.p_vaddr   = phdr.p_paddr = 0;
365         phdr.p_filesz  = phdr.p_memsz = phdr_sz;
366         phdr.p_align   = 0;
367
368         /* Add merged PT_NOTE program header*/
369         tmp = elfptr + sizeof(Elf32_Ehdr);
370         memcpy(tmp, &phdr, sizeof(phdr));
371         tmp += sizeof(phdr);
372
373         /* Remove unwanted PT_NOTE program headers. */
374         i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
375         *elfsz = *elfsz - i;
376         memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
377
378         /* Modify e_phnum to reflect merged headers. */
379         ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
380
381         return 0;
382 }
383
384 /* Add memory chunks represented by program headers to vmcore list. Also update
385  * the new offset fields of exported program headers. */
386 static int __init process_ptload_program_headers_elf64(char *elfptr,
387                                                 size_t elfsz,
388                                                 struct list_head *vc_list)
389 {
390         int i;
391         Elf64_Ehdr *ehdr_ptr;
392         Elf64_Phdr *phdr_ptr;
393         loff_t vmcore_off;
394         struct vmcore *new;
395
396         ehdr_ptr = (Elf64_Ehdr *)elfptr;
397         phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
398
399         /* First program header is PT_NOTE header. */
400         vmcore_off = sizeof(Elf64_Ehdr) +
401                         (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
402                         phdr_ptr->p_memsz; /* Note sections */
403
404         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
405                 if (phdr_ptr->p_type != PT_LOAD)
406                         continue;
407
408                 /* Add this contiguous chunk of memory to vmcore list.*/
409                 new = get_new_element();
410                 if (!new)
411                         return -ENOMEM;
412                 new->paddr = phdr_ptr->p_offset;
413                 new->size = phdr_ptr->p_memsz;
414                 list_add_tail(&new->list, vc_list);
415
416                 /* Update the program header offset. */
417                 phdr_ptr->p_offset = vmcore_off;
418                 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
419         }
420         return 0;
421 }
422
423 static int __init process_ptload_program_headers_elf32(char *elfptr,
424                                                 size_t elfsz,
425                                                 struct list_head *vc_list)
426 {
427         int i;
428         Elf32_Ehdr *ehdr_ptr;
429         Elf32_Phdr *phdr_ptr;
430         loff_t vmcore_off;
431         struct vmcore *new;
432
433         ehdr_ptr = (Elf32_Ehdr *)elfptr;
434         phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
435
436         /* First program header is PT_NOTE header. */
437         vmcore_off = sizeof(Elf32_Ehdr) +
438                         (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
439                         phdr_ptr->p_memsz; /* Note sections */
440
441         for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
442                 if (phdr_ptr->p_type != PT_LOAD)
443                         continue;
444
445                 /* Add this contiguous chunk of memory to vmcore list.*/
446                 new = get_new_element();
447                 if (!new)
448                         return -ENOMEM;
449                 new->paddr = phdr_ptr->p_offset;
450                 new->size = phdr_ptr->p_memsz;
451                 list_add_tail(&new->list, vc_list);
452
453                 /* Update the program header offset */
454                 phdr_ptr->p_offset = vmcore_off;
455                 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
456         }
457         return 0;
458 }
459
460 /* Sets offset fields of vmcore elements. */
461 static void __init set_vmcore_list_offsets_elf64(char *elfptr,
462                                                 struct list_head *vc_list)
463 {
464         loff_t vmcore_off;
465         Elf64_Ehdr *ehdr_ptr;
466         struct vmcore *m;
467
468         ehdr_ptr = (Elf64_Ehdr *)elfptr;
469
470         /* Skip Elf header and program headers. */
471         vmcore_off = sizeof(Elf64_Ehdr) +
472                         (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr);
473
474         list_for_each_entry(m, vc_list, list) {
475                 m->offset = vmcore_off;
476                 vmcore_off += m->size;
477         }
478 }
479
480 /* Sets offset fields of vmcore elements. */
481 static void __init set_vmcore_list_offsets_elf32(char *elfptr,
482                                                 struct list_head *vc_list)
483 {
484         loff_t vmcore_off;
485         Elf32_Ehdr *ehdr_ptr;
486         struct vmcore *m;
487
488         ehdr_ptr = (Elf32_Ehdr *)elfptr;
489
490         /* Skip Elf header and program headers. */
491         vmcore_off = sizeof(Elf32_Ehdr) +
492                         (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);
493
494         list_for_each_entry(m, vc_list, list) {
495                 m->offset = vmcore_off;
496                 vmcore_off += m->size;
497         }
498 }
499
500 static int __init parse_crash_elf64_headers(void)
501 {
502         int rc=0;
503         Elf64_Ehdr ehdr;
504         u64 addr;
505
506         addr = elfcorehdr_addr;
507
508         /* Read Elf header */
509         rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0);
510         if (rc < 0)
511                 return rc;
512
513         /* Do some basic Verification. */
514         if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
515                 (ehdr.e_type != ET_CORE) ||
516                 !vmcore_elf_check_arch(&ehdr) ||
517                 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
518                 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
519                 ehdr.e_version != EV_CURRENT ||
520                 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
521                 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
522                 ehdr.e_phnum == 0) {
523                 printk(KERN_WARNING "Warning: Core image elf header is not"
524                                         "sane\n");
525                 return -EINVAL;
526         }
527
528         /* Read in all elf headers. */
529         elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr);
530         elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
531         if (!elfcorebuf)
532                 return -ENOMEM;
533         addr = elfcorehdr_addr;
534         rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
535         if (rc < 0) {
536                 kfree(elfcorebuf);
537                 return rc;
538         }
539
540         /* Merge all PT_NOTE headers into one. */
541         rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
542         if (rc) {
543                 kfree(elfcorebuf);
544                 return rc;
545         }
546         rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
547                                                         &vmcore_list);
548         if (rc) {
549                 kfree(elfcorebuf);
550                 return rc;
551         }
552         set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list);
553         return 0;
554 }
555
556 static int __init parse_crash_elf32_headers(void)
557 {
558         int rc=0;
559         Elf32_Ehdr ehdr;
560         u64 addr;
561
562         addr = elfcorehdr_addr;
563
564         /* Read Elf header */
565         rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
566         if (rc < 0)
567                 return rc;
568
569         /* Do some basic Verification. */
570         if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
571                 (ehdr.e_type != ET_CORE) ||
572                 !elf_check_arch(&ehdr) ||
573                 ehdr.e_ident[EI_CLASS] != ELFCLASS32||
574                 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
575                 ehdr.e_version != EV_CURRENT ||
576                 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
577                 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
578                 ehdr.e_phnum == 0) {
579                 printk(KERN_WARNING "Warning: Core image elf header is not"
580                                         "sane\n");
581                 return -EINVAL;
582         }
583
584         /* Read in all elf headers. */
585         elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
586         elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
587         if (!elfcorebuf)
588                 return -ENOMEM;
589         addr = elfcorehdr_addr;
590         rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
591         if (rc < 0) {
592                 kfree(elfcorebuf);
593                 return rc;
594         }
595
596         /* Merge all PT_NOTE headers into one. */
597         rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
598         if (rc) {
599                 kfree(elfcorebuf);
600                 return rc;
601         }
602         rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
603                                                                 &vmcore_list);
604         if (rc) {
605                 kfree(elfcorebuf);
606                 return rc;
607         }
608         set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list);
609         return 0;
610 }
611
612 static int __init parse_crash_elf_headers(void)
613 {
614         unsigned char e_ident[EI_NIDENT];
615         u64 addr;
616         int rc=0;
617
618         addr = elfcorehdr_addr;
619         rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0);
620         if (rc < 0)
621                 return rc;
622         if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
623                 printk(KERN_WARNING "Warning: Core image elf header"
624                                         " not found\n");
625                 return -EINVAL;
626         }
627
628         if (e_ident[EI_CLASS] == ELFCLASS64) {
629                 rc = parse_crash_elf64_headers();
630                 if (rc)
631                         return rc;
632
633                 /* Determine vmcore size. */
634                 vmcore_size = get_vmcore_size_elf64(elfcorebuf);
635         } else if (e_ident[EI_CLASS] == ELFCLASS32) {
636                 rc = parse_crash_elf32_headers();
637                 if (rc)
638                         return rc;
639
640                 /* Determine vmcore size. */
641                 vmcore_size = get_vmcore_size_elf32(elfcorebuf);
642         } else {
643                 printk(KERN_WARNING "Warning: Core image elf header is not"
644                                         " sane\n");
645                 return -EINVAL;
646         }
647         return 0;
648 }
649
650 /* Init function for vmcore module. */
651 static int __init vmcore_init(void)
652 {
653         int rc = 0;
654
655         /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
656         if (!(elfcorehdr_addr < ELFCORE_ADDR_MAX))
657                 return rc;
658         rc = parse_crash_elf_headers();
659         if (rc) {
660                 printk(KERN_WARNING "Kdump: vmcore not initialized\n");
661                 return rc;
662         }
663
664         /* Initialize /proc/vmcore size if proc is already up. */
665         if (proc_vmcore)
666                 proc_vmcore->size = vmcore_size;
667         return 0;
668 }
669 module_init(vmcore_init)