xref: /openbmc/linux/fs/proc/vmcore.c (revision 643d1f7f)
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/a.out.h>
14 #include <linux/elf.h>
15 #include <linux/elfcore.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 /* Stores the physical address of elf header of crash image. */
37 unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
38 
39 struct proc_dir_entry *proc_vmcore = NULL;
40 
41 /* Reads a page from the oldmem device from given offset. */
42 static ssize_t read_from_oldmem(char *buf, size_t count,
43 				u64 *ppos, int userbuf)
44 {
45 	unsigned long pfn, offset;
46 	size_t nr_bytes;
47 	ssize_t read = 0, tmp;
48 
49 	if (!count)
50 		return 0;
51 
52 	offset = (unsigned long)(*ppos % PAGE_SIZE);
53 	pfn = (unsigned long)(*ppos / PAGE_SIZE);
54 	if (pfn > saved_max_pfn)
55 		return -EINVAL;
56 
57 	do {
58 		if (count > (PAGE_SIZE - offset))
59 			nr_bytes = PAGE_SIZE - offset;
60 		else
61 			nr_bytes = count;
62 
63 		tmp = copy_oldmem_page(pfn, buf, nr_bytes, offset, userbuf);
64 		if (tmp < 0)
65 			return tmp;
66 		*ppos += nr_bytes;
67 		count -= nr_bytes;
68 		buf += nr_bytes;
69 		read += nr_bytes;
70 		++pfn;
71 		offset = 0;
72 	} while (count);
73 
74 	return read;
75 }
76 
77 /* Maps vmcore file offset to respective physical address in memroy. */
78 static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list,
79 					struct vmcore **m_ptr)
80 {
81 	struct vmcore *m;
82 	u64 paddr;
83 
84 	list_for_each_entry(m, vc_list, list) {
85 		u64 start, end;
86 		start = m->offset;
87 		end = m->offset + m->size - 1;
88 		if (offset >= start && offset <= end) {
89 			paddr = m->paddr + offset - start;
90 			*m_ptr = m;
91 			return paddr;
92 		}
93 	}
94 	*m_ptr = NULL;
95 	return 0;
96 }
97 
98 /* Read from the ELF header and then the crash dump. On error, negative value is
99  * returned otherwise number of bytes read are returned.
100  */
101 static ssize_t read_vmcore(struct file *file, char __user *buffer,
102 				size_t buflen, loff_t *fpos)
103 {
104 	ssize_t acc = 0, tmp;
105 	size_t tsz;
106 	u64 start, nr_bytes;
107 	struct vmcore *curr_m = NULL;
108 
109 	if (buflen == 0 || *fpos >= vmcore_size)
110 		return 0;
111 
112 	/* trim buflen to not go beyond EOF */
113 	if (buflen > vmcore_size - *fpos)
114 		buflen = vmcore_size - *fpos;
115 
116 	/* Read ELF core header */
117 	if (*fpos < elfcorebuf_sz) {
118 		tsz = elfcorebuf_sz - *fpos;
119 		if (buflen < tsz)
120 			tsz = buflen;
121 		if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
122 			return -EFAULT;
123 		buflen -= tsz;
124 		*fpos += tsz;
125 		buffer += tsz;
126 		acc += tsz;
127 
128 		/* leave now if filled buffer already */
129 		if (buflen == 0)
130 			return acc;
131 	}
132 
133 	start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m);
134 	if (!curr_m)
135         	return -EINVAL;
136 	if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
137 		tsz = buflen;
138 
139 	/* Calculate left bytes in current memory segment. */
140 	nr_bytes = (curr_m->size - (start - curr_m->paddr));
141 	if (tsz > nr_bytes)
142 		tsz = nr_bytes;
143 
144 	while (buflen) {
145 		tmp = read_from_oldmem(buffer, tsz, &start, 1);
146 		if (tmp < 0)
147 			return tmp;
148 		buflen -= tsz;
149 		*fpos += tsz;
150 		buffer += tsz;
151 		acc += tsz;
152 		if (start >= (curr_m->paddr + curr_m->size)) {
153 			if (curr_m->list.next == &vmcore_list)
154 				return acc;	/*EOF*/
155 			curr_m = list_entry(curr_m->list.next,
156 						struct vmcore, list);
157 			start = curr_m->paddr;
158 		}
159 		if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
160 			tsz = buflen;
161 		/* Calculate left bytes in current memory segment. */
162 		nr_bytes = (curr_m->size - (start - curr_m->paddr));
163 		if (tsz > nr_bytes)
164 			tsz = nr_bytes;
165 	}
166 	return acc;
167 }
168 
169 static int open_vmcore(struct inode *inode, struct file *filp)
170 {
171 	return 0;
172 }
173 
174 const struct file_operations proc_vmcore_operations = {
175 	.read		= read_vmcore,
176 	.open		= open_vmcore,
177 };
178 
179 static struct vmcore* __init get_new_element(void)
180 {
181 	struct vmcore *p;
182 
183 	p = kmalloc(sizeof(*p), GFP_KERNEL);
184 	if (p)
185 		memset(p, 0, sizeof(*p));
186 	return p;
187 }
188 
189 static u64 __init get_vmcore_size_elf64(char *elfptr)
190 {
191 	int i;
192 	u64 size;
193 	Elf64_Ehdr *ehdr_ptr;
194 	Elf64_Phdr *phdr_ptr;
195 
196 	ehdr_ptr = (Elf64_Ehdr *)elfptr;
197 	phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
198 	size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr));
199 	for (i = 0; i < ehdr_ptr->e_phnum; i++) {
200 		size += phdr_ptr->p_memsz;
201 		phdr_ptr++;
202 	}
203 	return size;
204 }
205 
206 static u64 __init get_vmcore_size_elf32(char *elfptr)
207 {
208 	int i;
209 	u64 size;
210 	Elf32_Ehdr *ehdr_ptr;
211 	Elf32_Phdr *phdr_ptr;
212 
213 	ehdr_ptr = (Elf32_Ehdr *)elfptr;
214 	phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
215 	size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
216 	for (i = 0; i < ehdr_ptr->e_phnum; i++) {
217 		size += phdr_ptr->p_memsz;
218 		phdr_ptr++;
219 	}
220 	return size;
221 }
222 
223 /* Merges all the PT_NOTE headers into one. */
224 static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
225 						struct list_head *vc_list)
226 {
227 	int i, nr_ptnote=0, rc=0;
228 	char *tmp;
229 	Elf64_Ehdr *ehdr_ptr;
230 	Elf64_Phdr phdr, *phdr_ptr;
231 	Elf64_Nhdr *nhdr_ptr;
232 	u64 phdr_sz = 0, note_off;
233 
234 	ehdr_ptr = (Elf64_Ehdr *)elfptr;
235 	phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
236 	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
237 		int j;
238 		void *notes_section;
239 		struct vmcore *new;
240 		u64 offset, max_sz, sz, real_sz = 0;
241 		if (phdr_ptr->p_type != PT_NOTE)
242 			continue;
243 		nr_ptnote++;
244 		max_sz = phdr_ptr->p_memsz;
245 		offset = phdr_ptr->p_offset;
246 		notes_section = kmalloc(max_sz, GFP_KERNEL);
247 		if (!notes_section)
248 			return -ENOMEM;
249 		rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
250 		if (rc < 0) {
251 			kfree(notes_section);
252 			return rc;
253 		}
254 		nhdr_ptr = notes_section;
255 		for (j = 0; j < max_sz; j += sz) {
256 			if (nhdr_ptr->n_namesz == 0)
257 				break;
258 			sz = sizeof(Elf64_Nhdr) +
259 				((nhdr_ptr->n_namesz + 3) & ~3) +
260 				((nhdr_ptr->n_descsz + 3) & ~3);
261 			real_sz += sz;
262 			nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
263 		}
264 
265 		/* Add this contiguous chunk of notes section to vmcore list.*/
266 		new = get_new_element();
267 		if (!new) {
268 			kfree(notes_section);
269 			return -ENOMEM;
270 		}
271 		new->paddr = phdr_ptr->p_offset;
272 		new->size = real_sz;
273 		list_add_tail(&new->list, vc_list);
274 		phdr_sz += real_sz;
275 		kfree(notes_section);
276 	}
277 
278 	/* Prepare merged PT_NOTE program header. */
279 	phdr.p_type    = PT_NOTE;
280 	phdr.p_flags   = 0;
281 	note_off = sizeof(Elf64_Ehdr) +
282 			(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
283 	phdr.p_offset  = note_off;
284 	phdr.p_vaddr   = phdr.p_paddr = 0;
285 	phdr.p_filesz  = phdr.p_memsz = phdr_sz;
286 	phdr.p_align   = 0;
287 
288 	/* Add merged PT_NOTE program header*/
289 	tmp = elfptr + sizeof(Elf64_Ehdr);
290 	memcpy(tmp, &phdr, sizeof(phdr));
291 	tmp += sizeof(phdr);
292 
293 	/* Remove unwanted PT_NOTE program headers. */
294 	i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
295 	*elfsz = *elfsz - i;
296 	memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
297 
298 	/* Modify e_phnum to reflect merged headers. */
299 	ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
300 
301 	return 0;
302 }
303 
304 /* Merges all the PT_NOTE headers into one. */
305 static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
306 						struct list_head *vc_list)
307 {
308 	int i, nr_ptnote=0, rc=0;
309 	char *tmp;
310 	Elf32_Ehdr *ehdr_ptr;
311 	Elf32_Phdr phdr, *phdr_ptr;
312 	Elf32_Nhdr *nhdr_ptr;
313 	u64 phdr_sz = 0, note_off;
314 
315 	ehdr_ptr = (Elf32_Ehdr *)elfptr;
316 	phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
317 	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
318 		int j;
319 		void *notes_section;
320 		struct vmcore *new;
321 		u64 offset, max_sz, sz, real_sz = 0;
322 		if (phdr_ptr->p_type != PT_NOTE)
323 			continue;
324 		nr_ptnote++;
325 		max_sz = phdr_ptr->p_memsz;
326 		offset = phdr_ptr->p_offset;
327 		notes_section = kmalloc(max_sz, GFP_KERNEL);
328 		if (!notes_section)
329 			return -ENOMEM;
330 		rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
331 		if (rc < 0) {
332 			kfree(notes_section);
333 			return rc;
334 		}
335 		nhdr_ptr = notes_section;
336 		for (j = 0; j < max_sz; j += sz) {
337 			if (nhdr_ptr->n_namesz == 0)
338 				break;
339 			sz = sizeof(Elf32_Nhdr) +
340 				((nhdr_ptr->n_namesz + 3) & ~3) +
341 				((nhdr_ptr->n_descsz + 3) & ~3);
342 			real_sz += sz;
343 			nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
344 		}
345 
346 		/* Add this contiguous chunk of notes section to vmcore list.*/
347 		new = get_new_element();
348 		if (!new) {
349 			kfree(notes_section);
350 			return -ENOMEM;
351 		}
352 		new->paddr = phdr_ptr->p_offset;
353 		new->size = real_sz;
354 		list_add_tail(&new->list, vc_list);
355 		phdr_sz += real_sz;
356 		kfree(notes_section);
357 	}
358 
359 	/* Prepare merged PT_NOTE program header. */
360 	phdr.p_type    = PT_NOTE;
361 	phdr.p_flags   = 0;
362 	note_off = sizeof(Elf32_Ehdr) +
363 			(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
364 	phdr.p_offset  = note_off;
365 	phdr.p_vaddr   = phdr.p_paddr = 0;
366 	phdr.p_filesz  = phdr.p_memsz = phdr_sz;
367 	phdr.p_align   = 0;
368 
369 	/* Add merged PT_NOTE program header*/
370 	tmp = elfptr + sizeof(Elf32_Ehdr);
371 	memcpy(tmp, &phdr, sizeof(phdr));
372 	tmp += sizeof(phdr);
373 
374 	/* Remove unwanted PT_NOTE program headers. */
375 	i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
376 	*elfsz = *elfsz - i;
377 	memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
378 
379 	/* Modify e_phnum to reflect merged headers. */
380 	ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
381 
382 	return 0;
383 }
384 
385 /* Add memory chunks represented by program headers to vmcore list. Also update
386  * the new offset fields of exported program headers. */
387 static int __init process_ptload_program_headers_elf64(char *elfptr,
388 						size_t elfsz,
389 						struct list_head *vc_list)
390 {
391 	int i;
392 	Elf64_Ehdr *ehdr_ptr;
393 	Elf64_Phdr *phdr_ptr;
394 	loff_t vmcore_off;
395 	struct vmcore *new;
396 
397 	ehdr_ptr = (Elf64_Ehdr *)elfptr;
398 	phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
399 
400 	/* First program header is PT_NOTE header. */
401 	vmcore_off = sizeof(Elf64_Ehdr) +
402 			(ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
403 			phdr_ptr->p_memsz; /* Note sections */
404 
405 	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
406 		if (phdr_ptr->p_type != PT_LOAD)
407 			continue;
408 
409 		/* Add this contiguous chunk of memory to vmcore list.*/
410 		new = get_new_element();
411 		if (!new)
412 			return -ENOMEM;
413 		new->paddr = phdr_ptr->p_offset;
414 		new->size = phdr_ptr->p_memsz;
415 		list_add_tail(&new->list, vc_list);
416 
417 		/* Update the program header offset. */
418 		phdr_ptr->p_offset = vmcore_off;
419 		vmcore_off = vmcore_off + phdr_ptr->p_memsz;
420 	}
421 	return 0;
422 }
423 
424 static int __init process_ptload_program_headers_elf32(char *elfptr,
425 						size_t elfsz,
426 						struct list_head *vc_list)
427 {
428 	int i;
429 	Elf32_Ehdr *ehdr_ptr;
430 	Elf32_Phdr *phdr_ptr;
431 	loff_t vmcore_off;
432 	struct vmcore *new;
433 
434 	ehdr_ptr = (Elf32_Ehdr *)elfptr;
435 	phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
436 
437 	/* First program header is PT_NOTE header. */
438 	vmcore_off = sizeof(Elf32_Ehdr) +
439 			(ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
440 			phdr_ptr->p_memsz; /* Note sections */
441 
442 	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
443 		if (phdr_ptr->p_type != PT_LOAD)
444 			continue;
445 
446 		/* Add this contiguous chunk of memory to vmcore list.*/
447 		new = get_new_element();
448 		if (!new)
449 			return -ENOMEM;
450 		new->paddr = phdr_ptr->p_offset;
451 		new->size = phdr_ptr->p_memsz;
452 		list_add_tail(&new->list, vc_list);
453 
454 		/* Update the program header offset */
455 		phdr_ptr->p_offset = vmcore_off;
456 		vmcore_off = vmcore_off + phdr_ptr->p_memsz;
457 	}
458 	return 0;
459 }
460 
461 /* Sets offset fields of vmcore elements. */
462 static void __init set_vmcore_list_offsets_elf64(char *elfptr,
463 						struct list_head *vc_list)
464 {
465 	loff_t vmcore_off;
466 	Elf64_Ehdr *ehdr_ptr;
467 	struct vmcore *m;
468 
469 	ehdr_ptr = (Elf64_Ehdr *)elfptr;
470 
471 	/* Skip Elf header and program headers. */
472 	vmcore_off = sizeof(Elf64_Ehdr) +
473 			(ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr);
474 
475 	list_for_each_entry(m, vc_list, list) {
476 		m->offset = vmcore_off;
477 		vmcore_off += m->size;
478 	}
479 }
480 
481 /* Sets offset fields of vmcore elements. */
482 static void __init set_vmcore_list_offsets_elf32(char *elfptr,
483 						struct list_head *vc_list)
484 {
485 	loff_t vmcore_off;
486 	Elf32_Ehdr *ehdr_ptr;
487 	struct vmcore *m;
488 
489 	ehdr_ptr = (Elf32_Ehdr *)elfptr;
490 
491 	/* Skip Elf header and program headers. */
492 	vmcore_off = sizeof(Elf32_Ehdr) +
493 			(ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);
494 
495 	list_for_each_entry(m, vc_list, list) {
496 		m->offset = vmcore_off;
497 		vmcore_off += m->size;
498 	}
499 }
500 
501 static int __init parse_crash_elf64_headers(void)
502 {
503 	int rc=0;
504 	Elf64_Ehdr ehdr;
505 	u64 addr;
506 
507 	addr = elfcorehdr_addr;
508 
509 	/* Read Elf header */
510 	rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0);
511 	if (rc < 0)
512 		return rc;
513 
514 	/* Do some basic Verification. */
515 	if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
516 		(ehdr.e_type != ET_CORE) ||
517 		!vmcore_elf_check_arch(&ehdr) ||
518 		ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
519 		ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
520 		ehdr.e_version != EV_CURRENT ||
521 		ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
522 		ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
523 		ehdr.e_phnum == 0) {
524 		printk(KERN_WARNING "Warning: Core image elf header is not"
525 					"sane\n");
526 		return -EINVAL;
527 	}
528 
529 	/* Read in all elf headers. */
530 	elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr);
531 	elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
532 	if (!elfcorebuf)
533 		return -ENOMEM;
534 	addr = elfcorehdr_addr;
535 	rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
536 	if (rc < 0) {
537 		kfree(elfcorebuf);
538 		return rc;
539 	}
540 
541 	/* Merge all PT_NOTE headers into one. */
542 	rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
543 	if (rc) {
544 		kfree(elfcorebuf);
545 		return rc;
546 	}
547 	rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
548 							&vmcore_list);
549 	if (rc) {
550 		kfree(elfcorebuf);
551 		return rc;
552 	}
553 	set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list);
554 	return 0;
555 }
556 
557 static int __init parse_crash_elf32_headers(void)
558 {
559 	int rc=0;
560 	Elf32_Ehdr ehdr;
561 	u64 addr;
562 
563 	addr = elfcorehdr_addr;
564 
565 	/* Read Elf header */
566 	rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
567 	if (rc < 0)
568 		return rc;
569 
570 	/* Do some basic Verification. */
571 	if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
572 		(ehdr.e_type != ET_CORE) ||
573 		!elf_check_arch(&ehdr) ||
574 		ehdr.e_ident[EI_CLASS] != ELFCLASS32||
575 		ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
576 		ehdr.e_version != EV_CURRENT ||
577 		ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
578 		ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
579 		ehdr.e_phnum == 0) {
580 		printk(KERN_WARNING "Warning: Core image elf header is not"
581 					"sane\n");
582 		return -EINVAL;
583 	}
584 
585 	/* Read in all elf headers. */
586 	elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
587 	elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
588 	if (!elfcorebuf)
589 		return -ENOMEM;
590 	addr = elfcorehdr_addr;
591 	rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
592 	if (rc < 0) {
593 		kfree(elfcorebuf);
594 		return rc;
595 	}
596 
597 	/* Merge all PT_NOTE headers into one. */
598 	rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
599 	if (rc) {
600 		kfree(elfcorebuf);
601 		return rc;
602 	}
603 	rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
604 								&vmcore_list);
605 	if (rc) {
606 		kfree(elfcorebuf);
607 		return rc;
608 	}
609 	set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list);
610 	return 0;
611 }
612 
613 static int __init parse_crash_elf_headers(void)
614 {
615 	unsigned char e_ident[EI_NIDENT];
616 	u64 addr;
617 	int rc=0;
618 
619 	addr = elfcorehdr_addr;
620 	rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0);
621 	if (rc < 0)
622 		return rc;
623 	if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
624 		printk(KERN_WARNING "Warning: Core image elf header"
625 					" not found\n");
626 		return -EINVAL;
627 	}
628 
629 	if (e_ident[EI_CLASS] == ELFCLASS64) {
630 		rc = parse_crash_elf64_headers();
631 		if (rc)
632 			return rc;
633 
634 		/* Determine vmcore size. */
635 		vmcore_size = get_vmcore_size_elf64(elfcorebuf);
636 	} else if (e_ident[EI_CLASS] == ELFCLASS32) {
637 		rc = parse_crash_elf32_headers();
638 		if (rc)
639 			return rc;
640 
641 		/* Determine vmcore size. */
642 		vmcore_size = get_vmcore_size_elf32(elfcorebuf);
643 	} else {
644 		printk(KERN_WARNING "Warning: Core image elf header is not"
645 					" sane\n");
646 		return -EINVAL;
647 	}
648 	return 0;
649 }
650 
651 /* Init function for vmcore module. */
652 static int __init vmcore_init(void)
653 {
654 	int rc = 0;
655 
656 	/* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
657 	if (!(elfcorehdr_addr < ELFCORE_ADDR_MAX))
658 		return rc;
659 	rc = parse_crash_elf_headers();
660 	if (rc) {
661 		printk(KERN_WARNING "Kdump: vmcore not initialized\n");
662 		return rc;
663 	}
664 
665 	/* Initialize /proc/vmcore size if proc is already up. */
666 	if (proc_vmcore)
667 		proc_vmcore->size = vmcore_size;
668 	return 0;
669 }
670 module_init(vmcore_init)
671