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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 */
27static LIST_HEAD(vmcore_list);
28
29/* Stores the pointer to the buffer containing kernel elf core headers. */
30static char *elfcorebuf;
31static size_t elfcorebuf_sz;
32
33/* Total size of vmcore file. */
34static u64 vmcore_size;
35
36static 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 */
42static int (*oldmem_pfn_is_ram)(unsigned long pfn);
43
44int 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}
51EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram);
52
53void unregister_oldmem_pfn_is_ram(void)
54{
55 oldmem_pfn_is_ram = NULL;
56 wmb();
57}
58EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram);
59
60static 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. */
79static 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. */
119static 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 */
142static 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
210static const struct file_operations proc_vmcore_operations = {
211 .read = read_vmcore,
212 .llseek = default_llseek,
213};
214
215static struct vmcore* __init get_new_element(void)
216{
217 return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
218}
219
220static 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
237static 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. */
255static 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. */
336static 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. */
418static 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
455static 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. */
493static 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. */
513static 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
532static 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
588static 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
644static 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. */
683static 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}
701module_init(vmcore_init)
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/export.h>
16#include <linux/slab.h>
17#include <linux/highmem.h>
18#include <linux/bootmem.h>
19#include <linux/init.h>
20#include <linux/crash_dump.h>
21#include <linux/list.h>
22#include <asm/uaccess.h>
23#include <asm/io.h>
24
25/* List representing chunks of contiguous memory areas and their offsets in
26 * vmcore file.
27 */
28static LIST_HEAD(vmcore_list);
29
30/* Stores the pointer to the buffer containing kernel elf core headers. */
31static char *elfcorebuf;
32static size_t elfcorebuf_sz;
33
34/* Total size of vmcore file. */
35static u64 vmcore_size;
36
37static struct proc_dir_entry *proc_vmcore = NULL;
38
39/*
40 * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
41 * The called function has to take care of module refcounting.
42 */
43static int (*oldmem_pfn_is_ram)(unsigned long pfn);
44
45int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn))
46{
47 if (oldmem_pfn_is_ram)
48 return -EBUSY;
49 oldmem_pfn_is_ram = fn;
50 return 0;
51}
52EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram);
53
54void unregister_oldmem_pfn_is_ram(void)
55{
56 oldmem_pfn_is_ram = NULL;
57 wmb();
58}
59EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram);
60
61static int pfn_is_ram(unsigned long pfn)
62{
63 int (*fn)(unsigned long pfn);
64 /* pfn is ram unless fn() checks pagetype */
65 int ret = 1;
66
67 /*
68 * Ask hypervisor if the pfn is really ram.
69 * A ballooned page contains no data and reading from such a page
70 * will cause high load in the hypervisor.
71 */
72 fn = oldmem_pfn_is_ram;
73 if (fn)
74 ret = fn(pfn);
75
76 return ret;
77}
78
79/* Reads a page from the oldmem device from given offset. */
80static ssize_t read_from_oldmem(char *buf, size_t count,
81 u64 *ppos, int userbuf)
82{
83 unsigned long pfn, offset;
84 size_t nr_bytes;
85 ssize_t read = 0, tmp;
86
87 if (!count)
88 return 0;
89
90 offset = (unsigned long)(*ppos % PAGE_SIZE);
91 pfn = (unsigned long)(*ppos / PAGE_SIZE);
92
93 do {
94 if (count > (PAGE_SIZE - offset))
95 nr_bytes = PAGE_SIZE - offset;
96 else
97 nr_bytes = count;
98
99 /* If pfn is not ram, return zeros for sparse dump files */
100 if (pfn_is_ram(pfn) == 0)
101 memset(buf, 0, nr_bytes);
102 else {
103 tmp = copy_oldmem_page(pfn, buf, nr_bytes,
104 offset, userbuf);
105 if (tmp < 0)
106 return tmp;
107 }
108 *ppos += nr_bytes;
109 count -= nr_bytes;
110 buf += nr_bytes;
111 read += nr_bytes;
112 ++pfn;
113 offset = 0;
114 } while (count);
115
116 return read;
117}
118
119/* Maps vmcore file offset to respective physical address in memroy. */
120static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list,
121 struct vmcore **m_ptr)
122{
123 struct vmcore *m;
124 u64 paddr;
125
126 list_for_each_entry(m, vc_list, list) {
127 u64 start, end;
128 start = m->offset;
129 end = m->offset + m->size - 1;
130 if (offset >= start && offset <= end) {
131 paddr = m->paddr + offset - start;
132 *m_ptr = m;
133 return paddr;
134 }
135 }
136 *m_ptr = NULL;
137 return 0;
138}
139
140/* Read from the ELF header and then the crash dump. On error, negative value is
141 * returned otherwise number of bytes read are returned.
142 */
143static ssize_t read_vmcore(struct file *file, char __user *buffer,
144 size_t buflen, loff_t *fpos)
145{
146 ssize_t acc = 0, tmp;
147 size_t tsz;
148 u64 start, nr_bytes;
149 struct vmcore *curr_m = NULL;
150
151 if (buflen == 0 || *fpos >= vmcore_size)
152 return 0;
153
154 /* trim buflen to not go beyond EOF */
155 if (buflen > vmcore_size - *fpos)
156 buflen = vmcore_size - *fpos;
157
158 /* Read ELF core header */
159 if (*fpos < elfcorebuf_sz) {
160 tsz = elfcorebuf_sz - *fpos;
161 if (buflen < tsz)
162 tsz = buflen;
163 if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
164 return -EFAULT;
165 buflen -= tsz;
166 *fpos += tsz;
167 buffer += tsz;
168 acc += tsz;
169
170 /* leave now if filled buffer already */
171 if (buflen == 0)
172 return acc;
173 }
174
175 start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m);
176 if (!curr_m)
177 return -EINVAL;
178 if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
179 tsz = buflen;
180
181 /* Calculate left bytes in current memory segment. */
182 nr_bytes = (curr_m->size - (start - curr_m->paddr));
183 if (tsz > nr_bytes)
184 tsz = nr_bytes;
185
186 while (buflen) {
187 tmp = read_from_oldmem(buffer, tsz, &start, 1);
188 if (tmp < 0)
189 return tmp;
190 buflen -= tsz;
191 *fpos += tsz;
192 buffer += tsz;
193 acc += tsz;
194 if (start >= (curr_m->paddr + curr_m->size)) {
195 if (curr_m->list.next == &vmcore_list)
196 return acc; /*EOF*/
197 curr_m = list_entry(curr_m->list.next,
198 struct vmcore, list);
199 start = curr_m->paddr;
200 }
201 if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
202 tsz = buflen;
203 /* Calculate left bytes in current memory segment. */
204 nr_bytes = (curr_m->size - (start - curr_m->paddr));
205 if (tsz > nr_bytes)
206 tsz = nr_bytes;
207 }
208 return acc;
209}
210
211static const struct file_operations proc_vmcore_operations = {
212 .read = read_vmcore,
213 .llseek = default_llseek,
214};
215
216static struct vmcore* __init get_new_element(void)
217{
218 return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
219}
220
221static u64 __init get_vmcore_size_elf64(char *elfptr)
222{
223 int i;
224 u64 size;
225 Elf64_Ehdr *ehdr_ptr;
226 Elf64_Phdr *phdr_ptr;
227
228 ehdr_ptr = (Elf64_Ehdr *)elfptr;
229 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
230 size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr));
231 for (i = 0; i < ehdr_ptr->e_phnum; i++) {
232 size += phdr_ptr->p_memsz;
233 phdr_ptr++;
234 }
235 return size;
236}
237
238static u64 __init get_vmcore_size_elf32(char *elfptr)
239{
240 int i;
241 u64 size;
242 Elf32_Ehdr *ehdr_ptr;
243 Elf32_Phdr *phdr_ptr;
244
245 ehdr_ptr = (Elf32_Ehdr *)elfptr;
246 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
247 size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
248 for (i = 0; i < ehdr_ptr->e_phnum; i++) {
249 size += phdr_ptr->p_memsz;
250 phdr_ptr++;
251 }
252 return size;
253}
254
255/* Merges all the PT_NOTE headers into one. */
256static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
257 struct list_head *vc_list)
258{
259 int i, nr_ptnote=0, rc=0;
260 char *tmp;
261 Elf64_Ehdr *ehdr_ptr;
262 Elf64_Phdr phdr, *phdr_ptr;
263 Elf64_Nhdr *nhdr_ptr;
264 u64 phdr_sz = 0, note_off;
265
266 ehdr_ptr = (Elf64_Ehdr *)elfptr;
267 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
268 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
269 int j;
270 void *notes_section;
271 struct vmcore *new;
272 u64 offset, max_sz, sz, real_sz = 0;
273 if (phdr_ptr->p_type != PT_NOTE)
274 continue;
275 nr_ptnote++;
276 max_sz = phdr_ptr->p_memsz;
277 offset = phdr_ptr->p_offset;
278 notes_section = kmalloc(max_sz, GFP_KERNEL);
279 if (!notes_section)
280 return -ENOMEM;
281 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
282 if (rc < 0) {
283 kfree(notes_section);
284 return rc;
285 }
286 nhdr_ptr = notes_section;
287 for (j = 0; j < max_sz; j += sz) {
288 if (nhdr_ptr->n_namesz == 0)
289 break;
290 sz = sizeof(Elf64_Nhdr) +
291 ((nhdr_ptr->n_namesz + 3) & ~3) +
292 ((nhdr_ptr->n_descsz + 3) & ~3);
293 real_sz += sz;
294 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
295 }
296
297 /* Add this contiguous chunk of notes section to vmcore list.*/
298 new = get_new_element();
299 if (!new) {
300 kfree(notes_section);
301 return -ENOMEM;
302 }
303 new->paddr = phdr_ptr->p_offset;
304 new->size = real_sz;
305 list_add_tail(&new->list, vc_list);
306 phdr_sz += real_sz;
307 kfree(notes_section);
308 }
309
310 /* Prepare merged PT_NOTE program header. */
311 phdr.p_type = PT_NOTE;
312 phdr.p_flags = 0;
313 note_off = sizeof(Elf64_Ehdr) +
314 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
315 phdr.p_offset = note_off;
316 phdr.p_vaddr = phdr.p_paddr = 0;
317 phdr.p_filesz = phdr.p_memsz = phdr_sz;
318 phdr.p_align = 0;
319
320 /* Add merged PT_NOTE program header*/
321 tmp = elfptr + sizeof(Elf64_Ehdr);
322 memcpy(tmp, &phdr, sizeof(phdr));
323 tmp += sizeof(phdr);
324
325 /* Remove unwanted PT_NOTE program headers. */
326 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
327 *elfsz = *elfsz - i;
328 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
329
330 /* Modify e_phnum to reflect merged headers. */
331 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
332
333 return 0;
334}
335
336/* Merges all the PT_NOTE headers into one. */
337static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
338 struct list_head *vc_list)
339{
340 int i, nr_ptnote=0, rc=0;
341 char *tmp;
342 Elf32_Ehdr *ehdr_ptr;
343 Elf32_Phdr phdr, *phdr_ptr;
344 Elf32_Nhdr *nhdr_ptr;
345 u64 phdr_sz = 0, note_off;
346
347 ehdr_ptr = (Elf32_Ehdr *)elfptr;
348 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
349 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
350 int j;
351 void *notes_section;
352 struct vmcore *new;
353 u64 offset, max_sz, sz, real_sz = 0;
354 if (phdr_ptr->p_type != PT_NOTE)
355 continue;
356 nr_ptnote++;
357 max_sz = phdr_ptr->p_memsz;
358 offset = phdr_ptr->p_offset;
359 notes_section = kmalloc(max_sz, GFP_KERNEL);
360 if (!notes_section)
361 return -ENOMEM;
362 rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
363 if (rc < 0) {
364 kfree(notes_section);
365 return rc;
366 }
367 nhdr_ptr = notes_section;
368 for (j = 0; j < max_sz; j += sz) {
369 if (nhdr_ptr->n_namesz == 0)
370 break;
371 sz = sizeof(Elf32_Nhdr) +
372 ((nhdr_ptr->n_namesz + 3) & ~3) +
373 ((nhdr_ptr->n_descsz + 3) & ~3);
374 real_sz += sz;
375 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
376 }
377
378 /* Add this contiguous chunk of notes section to vmcore list.*/
379 new = get_new_element();
380 if (!new) {
381 kfree(notes_section);
382 return -ENOMEM;
383 }
384 new->paddr = phdr_ptr->p_offset;
385 new->size = real_sz;
386 list_add_tail(&new->list, vc_list);
387 phdr_sz += real_sz;
388 kfree(notes_section);
389 }
390
391 /* Prepare merged PT_NOTE program header. */
392 phdr.p_type = PT_NOTE;
393 phdr.p_flags = 0;
394 note_off = sizeof(Elf32_Ehdr) +
395 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
396 phdr.p_offset = note_off;
397 phdr.p_vaddr = phdr.p_paddr = 0;
398 phdr.p_filesz = phdr.p_memsz = phdr_sz;
399 phdr.p_align = 0;
400
401 /* Add merged PT_NOTE program header*/
402 tmp = elfptr + sizeof(Elf32_Ehdr);
403 memcpy(tmp, &phdr, sizeof(phdr));
404 tmp += sizeof(phdr);
405
406 /* Remove unwanted PT_NOTE program headers. */
407 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
408 *elfsz = *elfsz - i;
409 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
410
411 /* Modify e_phnum to reflect merged headers. */
412 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
413
414 return 0;
415}
416
417/* Add memory chunks represented by program headers to vmcore list. Also update
418 * the new offset fields of exported program headers. */
419static int __init process_ptload_program_headers_elf64(char *elfptr,
420 size_t elfsz,
421 struct list_head *vc_list)
422{
423 int i;
424 Elf64_Ehdr *ehdr_ptr;
425 Elf64_Phdr *phdr_ptr;
426 loff_t vmcore_off;
427 struct vmcore *new;
428
429 ehdr_ptr = (Elf64_Ehdr *)elfptr;
430 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
431
432 /* First program header is PT_NOTE header. */
433 vmcore_off = sizeof(Elf64_Ehdr) +
434 (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
435 phdr_ptr->p_memsz; /* Note sections */
436
437 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
438 if (phdr_ptr->p_type != PT_LOAD)
439 continue;
440
441 /* Add this contiguous chunk of memory to vmcore list.*/
442 new = get_new_element();
443 if (!new)
444 return -ENOMEM;
445 new->paddr = phdr_ptr->p_offset;
446 new->size = phdr_ptr->p_memsz;
447 list_add_tail(&new->list, vc_list);
448
449 /* Update the program header offset. */
450 phdr_ptr->p_offset = vmcore_off;
451 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
452 }
453 return 0;
454}
455
456static int __init process_ptload_program_headers_elf32(char *elfptr,
457 size_t elfsz,
458 struct list_head *vc_list)
459{
460 int i;
461 Elf32_Ehdr *ehdr_ptr;
462 Elf32_Phdr *phdr_ptr;
463 loff_t vmcore_off;
464 struct vmcore *new;
465
466 ehdr_ptr = (Elf32_Ehdr *)elfptr;
467 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
468
469 /* First program header is PT_NOTE header. */
470 vmcore_off = sizeof(Elf32_Ehdr) +
471 (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
472 phdr_ptr->p_memsz; /* Note sections */
473
474 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
475 if (phdr_ptr->p_type != PT_LOAD)
476 continue;
477
478 /* Add this contiguous chunk of memory to vmcore list.*/
479 new = get_new_element();
480 if (!new)
481 return -ENOMEM;
482 new->paddr = phdr_ptr->p_offset;
483 new->size = phdr_ptr->p_memsz;
484 list_add_tail(&new->list, vc_list);
485
486 /* Update the program header offset */
487 phdr_ptr->p_offset = vmcore_off;
488 vmcore_off = vmcore_off + phdr_ptr->p_memsz;
489 }
490 return 0;
491}
492
493/* Sets offset fields of vmcore elements. */
494static void __init set_vmcore_list_offsets_elf64(char *elfptr,
495 struct list_head *vc_list)
496{
497 loff_t vmcore_off;
498 Elf64_Ehdr *ehdr_ptr;
499 struct vmcore *m;
500
501 ehdr_ptr = (Elf64_Ehdr *)elfptr;
502
503 /* Skip Elf header and program headers. */
504 vmcore_off = sizeof(Elf64_Ehdr) +
505 (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr);
506
507 list_for_each_entry(m, vc_list, list) {
508 m->offset = vmcore_off;
509 vmcore_off += m->size;
510 }
511}
512
513/* Sets offset fields of vmcore elements. */
514static void __init set_vmcore_list_offsets_elf32(char *elfptr,
515 struct list_head *vc_list)
516{
517 loff_t vmcore_off;
518 Elf32_Ehdr *ehdr_ptr;
519 struct vmcore *m;
520
521 ehdr_ptr = (Elf32_Ehdr *)elfptr;
522
523 /* Skip Elf header and program headers. */
524 vmcore_off = sizeof(Elf32_Ehdr) +
525 (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);
526
527 list_for_each_entry(m, vc_list, list) {
528 m->offset = vmcore_off;
529 vmcore_off += m->size;
530 }
531}
532
533static int __init parse_crash_elf64_headers(void)
534{
535 int rc=0;
536 Elf64_Ehdr ehdr;
537 u64 addr;
538
539 addr = elfcorehdr_addr;
540
541 /* Read Elf header */
542 rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0);
543 if (rc < 0)
544 return rc;
545
546 /* Do some basic Verification. */
547 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
548 (ehdr.e_type != ET_CORE) ||
549 !vmcore_elf64_check_arch(&ehdr) ||
550 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
551 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
552 ehdr.e_version != EV_CURRENT ||
553 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
554 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
555 ehdr.e_phnum == 0) {
556 printk(KERN_WARNING "Warning: Core image elf header is not"
557 "sane\n");
558 return -EINVAL;
559 }
560
561 /* Read in all elf headers. */
562 elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr);
563 elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
564 if (!elfcorebuf)
565 return -ENOMEM;
566 addr = elfcorehdr_addr;
567 rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
568 if (rc < 0) {
569 kfree(elfcorebuf);
570 return rc;
571 }
572
573 /* Merge all PT_NOTE headers into one. */
574 rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
575 if (rc) {
576 kfree(elfcorebuf);
577 return rc;
578 }
579 rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
580 &vmcore_list);
581 if (rc) {
582 kfree(elfcorebuf);
583 return rc;
584 }
585 set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list);
586 return 0;
587}
588
589static int __init parse_crash_elf32_headers(void)
590{
591 int rc=0;
592 Elf32_Ehdr ehdr;
593 u64 addr;
594
595 addr = elfcorehdr_addr;
596
597 /* Read Elf header */
598 rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
599 if (rc < 0)
600 return rc;
601
602 /* Do some basic Verification. */
603 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
604 (ehdr.e_type != ET_CORE) ||
605 !elf_check_arch(&ehdr) ||
606 ehdr.e_ident[EI_CLASS] != ELFCLASS32||
607 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
608 ehdr.e_version != EV_CURRENT ||
609 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
610 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
611 ehdr.e_phnum == 0) {
612 printk(KERN_WARNING "Warning: Core image elf header is not"
613 "sane\n");
614 return -EINVAL;
615 }
616
617 /* Read in all elf headers. */
618 elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
619 elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
620 if (!elfcorebuf)
621 return -ENOMEM;
622 addr = elfcorehdr_addr;
623 rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
624 if (rc < 0) {
625 kfree(elfcorebuf);
626 return rc;
627 }
628
629 /* Merge all PT_NOTE headers into one. */
630 rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
631 if (rc) {
632 kfree(elfcorebuf);
633 return rc;
634 }
635 rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
636 &vmcore_list);
637 if (rc) {
638 kfree(elfcorebuf);
639 return rc;
640 }
641 set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list);
642 return 0;
643}
644
645static int __init parse_crash_elf_headers(void)
646{
647 unsigned char e_ident[EI_NIDENT];
648 u64 addr;
649 int rc=0;
650
651 addr = elfcorehdr_addr;
652 rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0);
653 if (rc < 0)
654 return rc;
655 if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
656 printk(KERN_WARNING "Warning: Core image elf header"
657 " not found\n");
658 return -EINVAL;
659 }
660
661 if (e_ident[EI_CLASS] == ELFCLASS64) {
662 rc = parse_crash_elf64_headers();
663 if (rc)
664 return rc;
665
666 /* Determine vmcore size. */
667 vmcore_size = get_vmcore_size_elf64(elfcorebuf);
668 } else if (e_ident[EI_CLASS] == ELFCLASS32) {
669 rc = parse_crash_elf32_headers();
670 if (rc)
671 return rc;
672
673 /* Determine vmcore size. */
674 vmcore_size = get_vmcore_size_elf32(elfcorebuf);
675 } else {
676 printk(KERN_WARNING "Warning: Core image elf header is not"
677 " sane\n");
678 return -EINVAL;
679 }
680 return 0;
681}
682
683/* Init function for vmcore module. */
684static int __init vmcore_init(void)
685{
686 int rc = 0;
687
688 /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
689 if (!(is_vmcore_usable()))
690 return rc;
691 rc = parse_crash_elf_headers();
692 if (rc) {
693 printk(KERN_WARNING "Kdump: vmcore not initialized\n");
694 return rc;
695 }
696
697 proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
698 if (proc_vmcore)
699 proc_vmcore->size = vmcore_size;
700 return 0;
701}
702module_init(vmcore_init)
703
704/* Cleanup function for vmcore module. */
705void vmcore_cleanup(void)
706{
707 struct list_head *pos, *next;
708
709 if (proc_vmcore) {
710 remove_proc_entry(proc_vmcore->name, proc_vmcore->parent);
711 proc_vmcore = NULL;
712 }
713
714 /* clear the vmcore list. */
715 list_for_each_safe(pos, next, &vmcore_list) {
716 struct vmcore *m;
717
718 m = list_entry(pos, struct vmcore, list);
719 list_del(&m->list);
720 kfree(m);
721 }
722 kfree(elfcorebuf);
723 elfcorebuf = NULL;
724}
725EXPORT_SYMBOL_GPL(vmcore_cleanup);