?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target...
[linux-btrfs-devel.git] / fs / proc / vmcore.c
blobcd99bf557650c4c727cdd9ac060ec28800a0ffe5
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 /*
39 * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
40 * The called function has to take care of module refcounting.
41 */
42 static int (*oldmem_pfn_is_ram)(unsigned long pfn);
43
44 int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn))
45 {
46 if (oldmem_pfn_is_ram)
47 return -EBUSY;
48 oldmem_pfn_is_ram = fn;
49 return 0;
50 }
51 EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram);
52
53 void unregister_oldmem_pfn_is_ram(void)
54 {
55 oldmem_pfn_is_ram = NULL;
56 wmb();
57 }
58 EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram);
59
60 static int pfn_is_ram(unsigned long pfn)
61 {
62 int (*fn)(unsigned long pfn);
63 /* pfn is ram unless fn() checks pagetype */
64 int ret = 1;
65
66 /*
67 * Ask hypervisor if the pfn is really ram.
68 * A ballooned page contains no data and reading from such a page
69 * will cause high load in the hypervisor.
70 */
71 fn = oldmem_pfn_is_ram;
72 if (fn)
73 ret = fn(pfn);
74
75 return ret;
76 }
77
78 /* Reads a page from the oldmem device from given offset. */
79 static ssize_t read_from_oldmem(char *buf, size_t count,
80 u64 *ppos, int userbuf)
81 {
82 unsigned long pfn, offset;
83 size_t nr_bytes;
84 ssize_t read = 0, tmp;
85
86 if (!count)
87 return 0;
88
89 offset = (unsigned long)(*ppos % PAGE_SIZE);
90 pfn = (unsigned long)(*ppos / PAGE_SIZE);
91
92 do {
93 if (count > (PAGE_SIZE - offset))
94 nr_bytes = PAGE_SIZE - offset;
95 else
96 nr_bytes = count;
97
98 /* If pfn is not ram, return zeros for sparse dump files */
99 if (pfn_is_ram(pfn) == 0)
100 memset(buf, 0, nr_bytes);
101 else {
102 tmp = copy_oldmem_page(pfn, buf, nr_bytes,
103 offset, userbuf);
104 if (tmp < 0)
105 return tmp;
106 }
107 *ppos += nr_bytes;
108 count -= nr_bytes;
109 buf += nr_bytes;
110 read += nr_bytes;
111 ++pfn;
112 offset = 0;
113 } while (count);
114
115 return read;
116 }
117
118 /* Maps vmcore file offset to respective physical address in memroy. */
119 static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list,
120 struct vmcore **m_ptr)
121 {
122 struct vmcore *m;
123 u64 paddr;
124
125 list_for_each_entry(m, vc_list, list) {
126 u64 start, end;
127 start = m->offset;
128 end = m->offset + m->size - 1;
129 if (offset >= start && offset <= end) {
130 paddr = m->paddr + offset - start;
131 *m_ptr = m;
132 return paddr;
133 }
134 }
135 *m_ptr = NULL;
136 return 0;
137 }
138
139 /* Read from the ELF header and then the crash dump. On error, negative value is
140 * returned otherwise number of bytes read are returned.
141 */
142 static ssize_t read_vmcore(struct file *file, char __user *buffer,
143 size_t buflen, loff_t *fpos)
144 {
145 ssize_t acc = 0, tmp;
146 size_t tsz;
147 u64 start, nr_bytes;
148 struct vmcore *curr_m = NULL;
149
150 if (buflen == 0 || *fpos >= vmcore_size)
151 return 0;
152
153 /* trim buflen to not go beyond EOF */
154 if (buflen > vmcore_size - *fpos)
155 buflen = vmcore_size - *fpos;
156
157 /* Read ELF core header */
158 if (*fpos < elfcorebuf_sz) {
159 tsz = elfcorebuf_sz - *fpos;
160 if (buflen < tsz)
161 tsz = buflen;
162 if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
163 return -EFAULT;
164 buflen -= tsz;
165 *fpos += tsz;
166 buffer += tsz;
167 acc += tsz;
168
169 /* leave now if filled buffer already */
170 if (buflen == 0)
171 return acc;
172 }
173
174 start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m);
175 if (!curr_m)
176 return -EINVAL;
177 if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
178 tsz = buflen;
179
180 /* Calculate left bytes in current memory segment. */
181 nr_bytes = (curr_m->size - (start - curr_m->paddr));
182 if (tsz > nr_bytes)
183 tsz = nr_bytes;
184
185 while (buflen) {
186 tmp = read_from_oldmem(buffer, tsz, &start, 1);
187 if (tmp < 0)
188 return tmp;
189 buflen -= tsz;
190 *fpos += tsz;
191 buffer += tsz;
192 acc += tsz;
193 if (start >= (curr_m->paddr + curr_m->size)) {
194 if (curr_m->list.next == &vmcore_list)
195 return acc; /*EOF*/
196 curr_m = list_entry(curr_m->list.next,
197 struct vmcore, list);
198 start = curr_m->paddr;
199 }
200 if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
201 tsz = buflen;
202 /* Calculate left bytes in current memory segment. */
203 nr_bytes = (curr_m->size - (start - curr_m->paddr));
204 if (tsz > nr_bytes)
205 tsz = nr_bytes;
206 }
207 return acc;
208 }
209
210 static const struct file_operations proc_vmcore_operations = {
211 .read = read_vmcore,
212 .llseek = default_llseek,
213 };
214
215 static struct vmcore* __init get_new_element(void)
216 {
217 return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
218 }
219
220 static u64 __init get_vmcore_size_elf64(char *elfptr)
221 {
222 int i;
223 u64 size;
224 Elf64_Ehdr *ehdr_ptr;
225 Elf64_Phdr *phdr_ptr;
226
227 ehdr_ptr = (Elf64_Ehdr *)elfptr;
228 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
229 size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr));
230 for (i = 0; i < ehdr_ptr->e_phnum; i++) {
231 size += phdr_ptr->p_memsz;
232 phdr_ptr++;
233 }
234 return size;
235 }
236
237 static u64 __init get_vmcore_size_elf32(char *elfptr)
238 {
239 int i;
240 u64 size;
241 Elf32_Ehdr *ehdr_ptr;
242 Elf32_Phdr *phdr_ptr;
243
244 ehdr_ptr = (Elf32_Ehdr *)elfptr;
245 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
246 size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
247 for (i = 0; i < ehdr_ptr->e_phnum; i++) {
248 size += phdr_ptr->p_memsz;
249 phdr_ptr++;
250 }
251 return size;
252 }
253
254 /* Merges all the PT_NOTE headers into one. */
255 static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
256 struct list_head *vc_list)
257 {
258 int i, nr_ptnote=0, rc=0;
259 char *tmp;
260 Elf64_Ehdr *ehdr_ptr;
261 Elf64_Phdr phdr, *phdr_ptr;
262 Elf64_Nhdr *nhdr_ptr;
263 u64 phdr_sz = 0, note_off;
264
265 ehdr_ptr = (Elf64_Ehdr *)elfptr;
266 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
267 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
268 int j;
269 void *notes_section;
270 struct vmcore *new;
271 u64 offset, max_sz, sz, real_sz = 0;
272 if (phdr_ptr->p_type != PT_NOTE)
273 continue;
274 nr_ptnote++;
275 max_sz = phdr_ptr->p_memsz;
276 offset = phdr_ptr->p_offset;
277 notes_section = kmalloc(max_sz, GFP_KERNEL);
278 if (!notes_section)
279 return -ENOMEM;
280 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
281 if (rc < 0) {
282 kfree(notes_section);
283 return rc;
284 }
285 nhdr_ptr = notes_section;
286 for (j = 0; j < max_sz; j += sz) {
287 if (nhdr_ptr->n_namesz == 0)
288 break;
289 sz = sizeof(Elf64_Nhdr) +
290 ((nhdr_ptr->n_namesz + 3) & ~3) +
291 ((nhdr_ptr->n_descsz + 3) & ~3);
292 real_sz += sz;
293 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
294 }
295
296 /* Add this contiguous chunk of notes section to vmcore list.*/
297 new = get_new_element();
298 if (!new) {
299 kfree(notes_section);
300 return -ENOMEM;
301 }
302 new->paddr = phdr_ptr->p_offset;
303 new->size = real_sz;
304 list_add_tail(&new->list, vc_list);
305 phdr_sz += real_sz;
306 kfree(notes_section);
307 }
308
309 /* Prepare merged PT_NOTE program header. */
310 phdr.p_type = PT_NOTE;
311 phdr.p_flags = 0;
312 note_off = sizeof(Elf64_Ehdr) +
313 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
314 phdr.p_offset = note_off;
315 phdr.p_vaddr = phdr.p_paddr = 0;
316 phdr.p_filesz = phdr.p_memsz = phdr_sz;
317 phdr.p_align = 0;
318
319 /* Add merged PT_NOTE program header*/
320 tmp = elfptr + sizeof(Elf64_Ehdr);
321 memcpy(tmp, &phdr, sizeof(phdr));
322 tmp += sizeof(phdr);
323
324 /* Remove unwanted PT_NOTE program headers. */
325 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
326 *elfsz = *elfsz - i;
327 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
328
329 /* Modify e_phnum to reflect merged headers. */
330 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
331
332 return 0;
333 }
334
335 /* Merges all the PT_NOTE headers into one. */
336 static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
337 struct list_head *vc_list)
338 {
339 int i, nr_ptnote=0, rc=0;
340 char *tmp;
341 Elf32_Ehdr *ehdr_ptr;
342 Elf32_Phdr phdr, *phdr_ptr;
343 Elf32_Nhdr *nhdr_ptr;
344 u64 phdr_sz = 0, note_off;
345
346 ehdr_ptr = (Elf32_Ehdr *)elfptr;
347 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
348 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
349 int j;
350 void *notes_section;
351 struct vmcore *new;
352 u64 offset, max_sz, sz, real_sz = 0;
353 if (phdr_ptr->p_type != PT_NOTE)
354 continue;
355 nr_ptnote++;
356 max_sz = phdr_ptr->p_memsz;
357 offset = phdr_ptr->p_offset;
358 notes_section = kmalloc(max_sz, GFP_KERNEL);
359 if (!notes_section)
360 return -ENOMEM;
361 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
362 if (rc < 0) {
363 kfree(notes_section);
364 return rc;
365 }
366 nhdr_ptr = notes_section;
367 for (j = 0; j < max_sz; j += sz) {
368 if (nhdr_ptr->n_namesz == 0)
369 break;
370 sz = sizeof(Elf32_Nhdr) +
371 ((nhdr_ptr->n_namesz + 3) & ~3) +
372 ((nhdr_ptr->n_descsz + 3) & ~3);
373 real_sz += sz;
374 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
375 }
376
377 /* Add this contiguous chunk of notes section to vmcore list.*/
378 new = get_new_element();
379 if (!new) {
380 kfree(notes_section);
381 return -ENOMEM;
382 }
383 new->paddr = phdr_ptr->p_offset;
384 new->size = real_sz;
385 list_add_tail(&new->list, vc_list);
386 phdr_sz += real_sz;
387 kfree(notes_section);
388 }
389
390 /* Prepare merged PT_NOTE program header. */
391 phdr.p_type = PT_NOTE;
392 phdr.p_flags = 0;
393 note_off = sizeof(Elf32_Ehdr) +
394 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
395 phdr.p_offset = note_off;
396 phdr.p_vaddr = phdr.p_paddr = 0;
397 phdr.p_filesz = phdr.p_memsz = phdr_sz;
398 phdr.p_align = 0;
399
400 /* Add merged PT_NOTE program header*/
401 tmp = elfptr + sizeof(Elf32_Ehdr);
402 memcpy(tmp, &phdr, sizeof(phdr));
403 tmp += sizeof(phdr);
404
405 /* Remove unwanted PT_NOTE program headers. */
406 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
407 *elfsz = *elfsz - i;
408 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
409
410 /* Modify e_phnum to reflect merged headers. */
411 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
412
413 return 0;
414 }
415
416 /* Add memory chunks represented by program headers to vmcore list. Also update
417 * the new offset fields of exported program headers. */
418 static int __init process_ptload_program_headers_elf64(char *elfptr,
419 size_t elfsz,
420 struct list_head *vc_list)
421 {
422 int i;
423 Elf64_Ehdr *ehdr_ptr;
424 Elf64_Phdr *phdr_ptr;
425 loff_t vmcore_off;
426 struct vmcore *new;
427
428 ehdr_ptr = (Elf64_Ehdr *)elfptr;
429 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
430
431 /* First program header is PT_NOTE header. */
432 vmcore_off = sizeof(Elf64_Ehdr) +
433 (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
434 phdr_ptr->p_memsz; /* Note sections */
435
436 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
437 if (phdr_ptr->p_type != PT_LOAD)
438 continue;
439
440 /* Add this contiguous chunk of memory to vmcore list.*/
441 new = get_new_element();
442 if (!new)
443 return -ENOMEM;
444 new->paddr = phdr_ptr->p_offset;
445 new->size = phdr_ptr->p_memsz;
446 list_add_tail(&new->list, vc_list);
447
448 /* Update the program header offset. */
449 phdr_ptr->p_offset = vmcore_off;
450 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
451 }
452 return 0;
453 }
454
455 static int __init process_ptload_program_headers_elf32(char *elfptr,
456 size_t elfsz,
457 struct list_head *vc_list)
458 {
459 int i;
460 Elf32_Ehdr *ehdr_ptr;
461 Elf32_Phdr *phdr_ptr;
462 loff_t vmcore_off;
463 struct vmcore *new;
464
465 ehdr_ptr = (Elf32_Ehdr *)elfptr;
466 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
467
468 /* First program header is PT_NOTE header. */
469 vmcore_off = sizeof(Elf32_Ehdr) +
470 (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
471 phdr_ptr->p_memsz; /* Note sections */
472
473 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
474 if (phdr_ptr->p_type != PT_LOAD)
475 continue;
476
477 /* Add this contiguous chunk of memory to vmcore list.*/
478 new = get_new_element();
479 if (!new)
480 return -ENOMEM;
481 new->paddr = phdr_ptr->p_offset;
482 new->size = phdr_ptr->p_memsz;
483 list_add_tail(&new->list, vc_list);
484
485 /* Update the program header offset */
486 phdr_ptr->p_offset = vmcore_off;
487 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
488 }
489 return 0;
490 }
491
492 /* Sets offset fields of vmcore elements. */
493 static void __init set_vmcore_list_offsets_elf64(char *elfptr,
494 struct list_head *vc_list)
495 {
496 loff_t vmcore_off;
497 Elf64_Ehdr *ehdr_ptr;
498 struct vmcore *m;
499
500 ehdr_ptr = (Elf64_Ehdr *)elfptr;
501
502 /* Skip Elf header and program headers. */
503 vmcore_off = sizeof(Elf64_Ehdr) +
504 (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr);
505
506 list_for_each_entry(m, vc_list, list) {
507 m->offset = vmcore_off;
508 vmcore_off += m->size;
509 }
510 }
511
512 /* Sets offset fields of vmcore elements. */
513 static void __init set_vmcore_list_offsets_elf32(char *elfptr,
514 struct list_head *vc_list)
515 {
516 loff_t vmcore_off;
517 Elf32_Ehdr *ehdr_ptr;
518 struct vmcore *m;
519
520 ehdr_ptr = (Elf32_Ehdr *)elfptr;
521
522 /* Skip Elf header and program headers. */
523 vmcore_off = sizeof(Elf32_Ehdr) +
524 (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);
525
526 list_for_each_entry(m, vc_list, list) {
527 m->offset = vmcore_off;
528 vmcore_off += m->size;
529 }
530 }
531
532 static int __init parse_crash_elf64_headers(void)
533 {
534 int rc=0;
535 Elf64_Ehdr ehdr;
536 u64 addr;
537
538 addr = elfcorehdr_addr;
539
540 /* Read Elf header */
541 rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0);
542 if (rc < 0)
543 return rc;
544
545 /* Do some basic Verification. */
546 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
547 (ehdr.e_type != ET_CORE) ||
548 !vmcore_elf64_check_arch(&ehdr) ||
549 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
550 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
551 ehdr.e_version != EV_CURRENT ||
552 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
553 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
554 ehdr.e_phnum == 0) {
555 printk(KERN_WARNING "Warning: Core image elf header is not"
556 "sane\n");
557 return -EINVAL;
558 }
559
560 /* Read in all elf headers. */
561 elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr);
562 elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
563 if (!elfcorebuf)
564 return -ENOMEM;
565 addr = elfcorehdr_addr;
566 rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
567 if (rc < 0) {
568 kfree(elfcorebuf);
569 return rc;
570 }
571
572 /* Merge all PT_NOTE headers into one. */
573 rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
574 if (rc) {
575 kfree(elfcorebuf);
576 return rc;
577 }
578 rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
579 &vmcore_list);
580 if (rc) {
581 kfree(elfcorebuf);
582 return rc;
583 }
584 set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list);
585 return 0;
586 }
587
588 static int __init parse_crash_elf32_headers(void)
589 {
590 int rc=0;
591 Elf32_Ehdr ehdr;
592 u64 addr;
593
594 addr = elfcorehdr_addr;
595
596 /* Read Elf header */
597 rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
598 if (rc < 0)
599 return rc;
600
601 /* Do some basic Verification. */
602 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
603 (ehdr.e_type != ET_CORE) ||
604 !elf_check_arch(&ehdr) ||
605 ehdr.e_ident[EI_CLASS] != ELFCLASS32||
606 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
607 ehdr.e_version != EV_CURRENT ||
608 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
609 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
610 ehdr.e_phnum == 0) {
611 printk(KERN_WARNING "Warning: Core image elf header is not"
612 "sane\n");
613 return -EINVAL;
614 }
615
616 /* Read in all elf headers. */
617 elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
618 elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
619 if (!elfcorebuf)
620 return -ENOMEM;
621 addr = elfcorehdr_addr;
622 rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
623 if (rc < 0) {
624 kfree(elfcorebuf);
625 return rc;
626 }
627
628 /* Merge all PT_NOTE headers into one. */
629 rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
630 if (rc) {
631 kfree(elfcorebuf);
632 return rc;
633 }
634 rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
635 &vmcore_list);
636 if (rc) {
637 kfree(elfcorebuf);
638 return rc;
639 }
640 set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list);
641 return 0;
642 }
643
644 static int __init parse_crash_elf_headers(void)
645 {
646 unsigned char e_ident[EI_NIDENT];
647 u64 addr;
648 int rc=0;
649
650 addr = elfcorehdr_addr;
651 rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0);
652 if (rc < 0)
653 return rc;
654 if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
655 printk(KERN_WARNING "Warning: Core image elf header"
656 " not found\n");
657 return -EINVAL;
658 }
659
660 if (e_ident[EI_CLASS] == ELFCLASS64) {
661 rc = parse_crash_elf64_headers();
662 if (rc)
663 return rc;
664
665 /* Determine vmcore size. */
666 vmcore_size = get_vmcore_size_elf64(elfcorebuf);
667 } else if (e_ident[EI_CLASS] == ELFCLASS32) {
668 rc = parse_crash_elf32_headers();
669 if (rc)
670 return rc;
671
672 /* Determine vmcore size. */
673 vmcore_size = get_vmcore_size_elf32(elfcorebuf);
674 } else {
675 printk(KERN_WARNING "Warning: Core image elf header is not"
676 " sane\n");
677 return -EINVAL;
678 }
679 return 0;
680 }
681
682 /* Init function for vmcore module. */
683 static int __init vmcore_init(void)
684 {
685 int rc = 0;
686
687 /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
688 if (!(is_vmcore_usable()))
689 return rc;
690 rc = parse_crash_elf_headers();
691 if (rc) {
692 printk(KERN_WARNING "Kdump: vmcore not initialized\n");
693 return rc;
694 }
695
696 proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
697 if (proc_vmcore)
698 proc_vmcore->size = vmcore_size;
699 return 0;
700 }
701 module_init(vmcore_init)
Linux Btrfs Development