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/fs/proc/vmcore.c

https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t
C | 701 lines | 542 code | 89 blank | 70 comment | 100 complexity | bf00e369d00f23656ec348fdfe9ffa02 MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
  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)