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
11 #include <linux/kcore.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/printk.h>
19 #include <linux/bootmem.h>
20 #include <linux/init.h>
21 #include <linux/crash_dump.h>
22 #include <linux/list.h>
23 #include <linux/vmalloc.h>
24 #include <asm/uaccess.h>
28 /* List representing chunks of contiguous memory areas and their offsets in
31 static LIST_HEAD(vmcore_list);
33 /* Stores the pointer to the buffer containing kernel elf core headers. */
34 static char *elfcorebuf;
35 static size_t elfcorebuf_sz;
36 static size_t elfcorebuf_sz_orig;
38 static char *elfnotes_buf;
39 static size_t elfnotes_sz;
41 /* Total size of vmcore file. */
42 static u64 vmcore_size;
44 static struct proc_dir_entry *proc_vmcore = NULL;
47 * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
48 * The called function has to take care of module refcounting.
50 static int (*oldmem_pfn_is_ram)(unsigned long pfn);
52 int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn))
54 if (oldmem_pfn_is_ram)
56 oldmem_pfn_is_ram = fn;
59 EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram);
61 void unregister_oldmem_pfn_is_ram(void)
63 oldmem_pfn_is_ram = NULL;
66 EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram);
68 static int pfn_is_ram(unsigned long pfn)
70 int (*fn)(unsigned long pfn);
71 /* pfn is ram unless fn() checks pagetype */
75 * Ask hypervisor if the pfn is really ram.
76 * A ballooned page contains no data and reading from such a page
77 * will cause high load in the hypervisor.
79 fn = oldmem_pfn_is_ram;
86 /* Reads a page from the oldmem device from given offset. */
87 static ssize_t read_from_oldmem(char *buf, size_t count,
88 u64 *ppos, int userbuf)
90 unsigned long pfn, offset;
92 ssize_t read = 0, tmp;
97 offset = (unsigned long)(*ppos % PAGE_SIZE);
98 pfn = (unsigned long)(*ppos / PAGE_SIZE);
101 if (count > (PAGE_SIZE - offset))
102 nr_bytes = PAGE_SIZE - offset;
106 /* If pfn is not ram, return zeros for sparse dump files */
107 if (pfn_is_ram(pfn) == 0)
108 memset(buf, 0, nr_bytes);
110 tmp = copy_oldmem_page(pfn, buf, nr_bytes,
127 * Architectures may override this function to allocate ELF header in 2nd kernel
129 int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
135 * Architectures may override this function to free header
137 void __weak elfcorehdr_free(unsigned long long addr)
141 * Architectures may override this function to read from ELF header
143 ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos)
145 return read_from_oldmem(buf, count, ppos, 0);
149 * Architectures may override this function to read from notes sections
151 ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
153 return read_from_oldmem(buf, count, ppos, 0);
156 /* Read from the ELF header and then the crash dump. On error, negative value is
157 * returned otherwise number of bytes read are returned.
159 static ssize_t read_vmcore(struct file *file, char __user *buffer,
160 size_t buflen, loff_t *fpos)
162 ssize_t acc = 0, tmp;
165 struct vmcore *m = NULL;
167 if (buflen == 0 || *fpos >= vmcore_size)
170 /* trim buflen to not go beyond EOF */
171 if (buflen > vmcore_size - *fpos)
172 buflen = vmcore_size - *fpos;
174 /* Read ELF core header */
175 if (*fpos < elfcorebuf_sz) {
176 tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen);
177 if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
184 /* leave now if filled buffer already */
189 /* Read Elf note segment */
190 if (*fpos < elfcorebuf_sz + elfnotes_sz) {
193 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen);
194 kaddr = elfnotes_buf + *fpos - elfcorebuf_sz;
195 if (copy_to_user(buffer, kaddr, tsz))
202 /* leave now if filled buffer already */
207 list_for_each_entry(m, &vmcore_list, list) {
208 if (*fpos < m->offset + m->size) {
209 tsz = min_t(size_t, m->offset + m->size - *fpos, buflen);
210 start = m->paddr + *fpos - m->offset;
211 tmp = read_from_oldmem(buffer, tsz, &start, 1);
219 /* leave now if filled buffer already */
229 * alloc_elfnotes_buf - allocate buffer for ELF note segment in
232 * @notes_sz: size of buffer
234 * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap
235 * the buffer to user-space by means of remap_vmalloc_range().
237 * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is
238 * disabled and there's no need to allow users to mmap the buffer.
240 static inline char *alloc_elfnotes_buf(size_t notes_sz)
243 return vmalloc_user(notes_sz);
245 return vzalloc(notes_sz);
250 * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is
251 * essential for mmap_vmcore() in order to map physically
252 * non-contiguous objects (ELF header, ELF note segment and memory
253 * regions in the 1st kernel pointed to by PT_LOAD entries) into
254 * virtually contiguous user-space in ELF layout.
256 #if defined(CONFIG_MMU) && !defined(CONFIG_S390)
257 static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
259 size_t size = vma->vm_end - vma->vm_start;
260 u64 start, end, len, tsz;
263 start = (u64)vma->vm_pgoff << PAGE_SHIFT;
266 if (size > vmcore_size || end > vmcore_size)
269 if (vma->vm_flags & (VM_WRITE | VM_EXEC))
272 vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC);
273 vma->vm_flags |= VM_MIXEDMAP;
277 if (start < elfcorebuf_sz) {
280 tsz = min(elfcorebuf_sz - (size_t)start, size);
281 pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT;
282 if (remap_pfn_range(vma, vma->vm_start, pfn, tsz,
293 if (start < elfcorebuf_sz + elfnotes_sz) {
296 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size);
297 kaddr = elfnotes_buf + start - elfcorebuf_sz;
298 if (remap_vmalloc_range_partial(vma, vma->vm_start + len,
309 list_for_each_entry(m, &vmcore_list, list) {
310 if (start < m->offset + m->size) {
313 tsz = min_t(size_t, m->offset + m->size - start, size);
314 paddr = m->paddr + start - m->offset;
315 if (remap_pfn_range(vma, vma->vm_start + len,
316 paddr >> PAGE_SHIFT, tsz,
330 do_munmap(vma->vm_mm, vma->vm_start, len);
334 static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
340 static const struct file_operations proc_vmcore_operations = {
342 .llseek = default_llseek,
346 static struct vmcore* __init get_new_element(void)
348 return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
351 static u64 __init get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
352 struct list_head *vc_list)
357 size = elfsz + elfnotesegsz;
358 list_for_each_entry(m, vc_list, list) {
365 * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry
367 * @ehdr_ptr: ELF header
369 * This function updates p_memsz member of each PT_NOTE entry in the
370 * program header table pointed to by @ehdr_ptr to real size of ELF
373 static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr)
376 Elf64_Phdr *phdr_ptr;
377 Elf64_Nhdr *nhdr_ptr;
379 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
380 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
382 u64 offset, max_sz, sz, real_sz = 0;
383 if (phdr_ptr->p_type != PT_NOTE)
385 max_sz = phdr_ptr->p_memsz;
386 offset = phdr_ptr->p_offset;
387 notes_section = kmalloc(max_sz, GFP_KERNEL);
390 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
392 kfree(notes_section);
395 nhdr_ptr = notes_section;
396 while (real_sz < max_sz) {
397 if (nhdr_ptr->n_namesz == 0)
399 sz = sizeof(Elf64_Nhdr) +
400 ((nhdr_ptr->n_namesz + 3) & ~3) +
401 ((nhdr_ptr->n_descsz + 3) & ~3);
403 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
405 kfree(notes_section);
406 phdr_ptr->p_memsz = real_sz;
413 * get_note_number_and_size_elf64 - get the number of PT_NOTE program
414 * headers and sum of real size of their ELF note segment headers and
417 * @ehdr_ptr: ELF header
418 * @nr_ptnote: buffer for the number of PT_NOTE program headers
419 * @sz_ptnote: buffer for size of unique PT_NOTE program header
421 * This function is used to merge multiple PT_NOTE program headers
422 * into a unique single one. The resulting unique entry will have
423 * @sz_ptnote in its phdr->p_mem.
425 * It is assumed that program headers with PT_NOTE type pointed to by
426 * @ehdr_ptr has already been updated by update_note_header_size_elf64
427 * and each of PT_NOTE program headers has actual ELF note segment
428 * size in its p_memsz member.
430 static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr,
431 int *nr_ptnote, u64 *sz_ptnote)
434 Elf64_Phdr *phdr_ptr;
436 *nr_ptnote = *sz_ptnote = 0;
438 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
439 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
440 if (phdr_ptr->p_type != PT_NOTE)
443 *sz_ptnote += phdr_ptr->p_memsz;
450 * copy_notes_elf64 - copy ELF note segments in a given buffer
452 * @ehdr_ptr: ELF header
453 * @notes_buf: buffer into which ELF note segments are copied
455 * This function is used to copy ELF note segment in the 1st kernel
456 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
457 * size of the buffer @notes_buf is equal to or larger than sum of the
458 * real ELF note segment headers and data.
460 * It is assumed that program headers with PT_NOTE type pointed to by
461 * @ehdr_ptr has already been updated by update_note_header_size_elf64
462 * and each of PT_NOTE program headers has actual ELF note segment
463 * size in its p_memsz member.
465 static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf)
468 Elf64_Phdr *phdr_ptr;
470 phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1);
472 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
474 if (phdr_ptr->p_type != PT_NOTE)
476 offset = phdr_ptr->p_offset;
477 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
481 notes_buf += phdr_ptr->p_memsz;
487 /* Merges all the PT_NOTE headers into one. */
488 static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
489 char **notes_buf, size_t *notes_sz)
491 int i, nr_ptnote=0, rc=0;
493 Elf64_Ehdr *ehdr_ptr;
495 u64 phdr_sz = 0, note_off;
497 ehdr_ptr = (Elf64_Ehdr *)elfptr;
499 rc = update_note_header_size_elf64(ehdr_ptr);
503 rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz);
507 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
508 *notes_buf = alloc_elfnotes_buf(*notes_sz);
512 rc = copy_notes_elf64(ehdr_ptr, *notes_buf);
516 /* Prepare merged PT_NOTE program header. */
517 phdr.p_type = PT_NOTE;
519 note_off = sizeof(Elf64_Ehdr) +
520 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
521 phdr.p_offset = roundup(note_off, PAGE_SIZE);
522 phdr.p_vaddr = phdr.p_paddr = 0;
523 phdr.p_filesz = phdr.p_memsz = phdr_sz;
526 /* Add merged PT_NOTE program header*/
527 tmp = elfptr + sizeof(Elf64_Ehdr);
528 memcpy(tmp, &phdr, sizeof(phdr));
531 /* Remove unwanted PT_NOTE program headers. */
532 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
534 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
535 memset(elfptr + *elfsz, 0, i);
536 *elfsz = roundup(*elfsz, PAGE_SIZE);
538 /* Modify e_phnum to reflect merged headers. */
539 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
545 * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry
547 * @ehdr_ptr: ELF header
549 * This function updates p_memsz member of each PT_NOTE entry in the
550 * program header table pointed to by @ehdr_ptr to real size of ELF
553 static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr)
556 Elf32_Phdr *phdr_ptr;
557 Elf32_Nhdr *nhdr_ptr;
559 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
560 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
562 u64 offset, max_sz, sz, real_sz = 0;
563 if (phdr_ptr->p_type != PT_NOTE)
565 max_sz = phdr_ptr->p_memsz;
566 offset = phdr_ptr->p_offset;
567 notes_section = kmalloc(max_sz, GFP_KERNEL);
570 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
572 kfree(notes_section);
575 nhdr_ptr = notes_section;
576 while (real_sz < max_sz) {
577 if (nhdr_ptr->n_namesz == 0)
579 sz = sizeof(Elf32_Nhdr) +
580 ((nhdr_ptr->n_namesz + 3) & ~3) +
581 ((nhdr_ptr->n_descsz + 3) & ~3);
583 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
585 kfree(notes_section);
586 phdr_ptr->p_memsz = real_sz;
593 * get_note_number_and_size_elf32 - get the number of PT_NOTE program
594 * headers and sum of real size of their ELF note segment headers and
597 * @ehdr_ptr: ELF header
598 * @nr_ptnote: buffer for the number of PT_NOTE program headers
599 * @sz_ptnote: buffer for size of unique PT_NOTE program header
601 * This function is used to merge multiple PT_NOTE program headers
602 * into a unique single one. The resulting unique entry will have
603 * @sz_ptnote in its phdr->p_mem.
605 * It is assumed that program headers with PT_NOTE type pointed to by
606 * @ehdr_ptr has already been updated by update_note_header_size_elf32
607 * and each of PT_NOTE program headers has actual ELF note segment
608 * size in its p_memsz member.
610 static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr,
611 int *nr_ptnote, u64 *sz_ptnote)
614 Elf32_Phdr *phdr_ptr;
616 *nr_ptnote = *sz_ptnote = 0;
618 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
619 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
620 if (phdr_ptr->p_type != PT_NOTE)
623 *sz_ptnote += phdr_ptr->p_memsz;
630 * copy_notes_elf32 - copy ELF note segments in a given buffer
632 * @ehdr_ptr: ELF header
633 * @notes_buf: buffer into which ELF note segments are copied
635 * This function is used to copy ELF note segment in the 1st kernel
636 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
637 * size of the buffer @notes_buf is equal to or larger than sum of the
638 * real ELF note segment headers and data.
640 * It is assumed that program headers with PT_NOTE type pointed to by
641 * @ehdr_ptr has already been updated by update_note_header_size_elf32
642 * and each of PT_NOTE program headers has actual ELF note segment
643 * size in its p_memsz member.
645 static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf)
648 Elf32_Phdr *phdr_ptr;
650 phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1);
652 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
654 if (phdr_ptr->p_type != PT_NOTE)
656 offset = phdr_ptr->p_offset;
657 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
661 notes_buf += phdr_ptr->p_memsz;
667 /* Merges all the PT_NOTE headers into one. */
668 static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
669 char **notes_buf, size_t *notes_sz)
671 int i, nr_ptnote=0, rc=0;
673 Elf32_Ehdr *ehdr_ptr;
675 u64 phdr_sz = 0, note_off;
677 ehdr_ptr = (Elf32_Ehdr *)elfptr;
679 rc = update_note_header_size_elf32(ehdr_ptr);
683 rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz);
687 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
688 *notes_buf = alloc_elfnotes_buf(*notes_sz);
692 rc = copy_notes_elf32(ehdr_ptr, *notes_buf);
696 /* Prepare merged PT_NOTE program header. */
697 phdr.p_type = PT_NOTE;
699 note_off = sizeof(Elf32_Ehdr) +
700 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
701 phdr.p_offset = roundup(note_off, PAGE_SIZE);
702 phdr.p_vaddr = phdr.p_paddr = 0;
703 phdr.p_filesz = phdr.p_memsz = phdr_sz;
706 /* Add merged PT_NOTE program header*/
707 tmp = elfptr + sizeof(Elf32_Ehdr);
708 memcpy(tmp, &phdr, sizeof(phdr));
711 /* Remove unwanted PT_NOTE program headers. */
712 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
714 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
715 memset(elfptr + *elfsz, 0, i);
716 *elfsz = roundup(*elfsz, PAGE_SIZE);
718 /* Modify e_phnum to reflect merged headers. */
719 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
724 /* Add memory chunks represented by program headers to vmcore list. Also update
725 * the new offset fields of exported program headers. */
726 static int __init process_ptload_program_headers_elf64(char *elfptr,
729 struct list_head *vc_list)
732 Elf64_Ehdr *ehdr_ptr;
733 Elf64_Phdr *phdr_ptr;
737 ehdr_ptr = (Elf64_Ehdr *)elfptr;
738 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
740 /* Skip Elf header, program headers and Elf note segment. */
741 vmcore_off = elfsz + elfnotes_sz;
743 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
744 u64 paddr, start, end, size;
746 if (phdr_ptr->p_type != PT_LOAD)
749 paddr = phdr_ptr->p_offset;
750 start = rounddown(paddr, PAGE_SIZE);
751 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
754 /* Add this contiguous chunk of memory to vmcore list.*/
755 new = get_new_element();
760 list_add_tail(&new->list, vc_list);
762 /* Update the program header offset. */
763 phdr_ptr->p_offset = vmcore_off + (paddr - start);
764 vmcore_off = vmcore_off + size;
769 static int __init process_ptload_program_headers_elf32(char *elfptr,
772 struct list_head *vc_list)
775 Elf32_Ehdr *ehdr_ptr;
776 Elf32_Phdr *phdr_ptr;
780 ehdr_ptr = (Elf32_Ehdr *)elfptr;
781 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
783 /* Skip Elf header, program headers and Elf note segment. */
784 vmcore_off = elfsz + elfnotes_sz;
786 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
787 u64 paddr, start, end, size;
789 if (phdr_ptr->p_type != PT_LOAD)
792 paddr = phdr_ptr->p_offset;
793 start = rounddown(paddr, PAGE_SIZE);
794 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
797 /* Add this contiguous chunk of memory to vmcore list.*/
798 new = get_new_element();
803 list_add_tail(&new->list, vc_list);
805 /* Update the program header offset */
806 phdr_ptr->p_offset = vmcore_off + (paddr - start);
807 vmcore_off = vmcore_off + size;
812 /* Sets offset fields of vmcore elements. */
813 static void __init set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz,
814 struct list_head *vc_list)
819 /* Skip Elf header, program headers and Elf note segment. */
820 vmcore_off = elfsz + elfnotes_sz;
822 list_for_each_entry(m, vc_list, list) {
823 m->offset = vmcore_off;
824 vmcore_off += m->size;
828 static void free_elfcorebuf(void)
830 free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig));
836 static int __init parse_crash_elf64_headers(void)
842 addr = elfcorehdr_addr;
844 /* Read Elf header */
845 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr);
849 /* Do some basic Verification. */
850 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
851 (ehdr.e_type != ET_CORE) ||
852 !vmcore_elf64_check_arch(&ehdr) ||
853 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
854 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
855 ehdr.e_version != EV_CURRENT ||
856 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
857 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
859 pr_warn("Warning: Core image elf header is not sane\n");
863 /* Read in all elf headers. */
864 elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) +
865 ehdr.e_phnum * sizeof(Elf64_Phdr);
866 elfcorebuf_sz = elfcorebuf_sz_orig;
867 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
868 get_order(elfcorebuf_sz_orig));
871 addr = elfcorehdr_addr;
872 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
876 /* Merge all PT_NOTE headers into one. */
877 rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz,
878 &elfnotes_buf, &elfnotes_sz);
881 rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
882 elfnotes_sz, &vmcore_list);
885 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
892 static int __init parse_crash_elf32_headers(void)
898 addr = elfcorehdr_addr;
900 /* Read Elf header */
901 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr);
905 /* Do some basic Verification. */
906 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
907 (ehdr.e_type != ET_CORE) ||
908 !elf_check_arch(&ehdr) ||
909 ehdr.e_ident[EI_CLASS] != ELFCLASS32||
910 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
911 ehdr.e_version != EV_CURRENT ||
912 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
913 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
915 pr_warn("Warning: Core image elf header is not sane\n");
919 /* Read in all elf headers. */
920 elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
921 elfcorebuf_sz = elfcorebuf_sz_orig;
922 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
923 get_order(elfcorebuf_sz_orig));
926 addr = elfcorehdr_addr;
927 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
931 /* Merge all PT_NOTE headers into one. */
932 rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz,
933 &elfnotes_buf, &elfnotes_sz);
936 rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
937 elfnotes_sz, &vmcore_list);
940 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
947 static int __init parse_crash_elf_headers(void)
949 unsigned char e_ident[EI_NIDENT];
953 addr = elfcorehdr_addr;
954 rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr);
957 if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
958 pr_warn("Warning: Core image elf header not found\n");
962 if (e_ident[EI_CLASS] == ELFCLASS64) {
963 rc = parse_crash_elf64_headers();
966 } else if (e_ident[EI_CLASS] == ELFCLASS32) {
967 rc = parse_crash_elf32_headers();
971 pr_warn("Warning: Core image elf header is not sane\n");
975 /* Determine vmcore size. */
976 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
982 /* Init function for vmcore module. */
983 static int __init vmcore_init(void)
987 /* Allow architectures to allocate ELF header in 2nd kernel */
988 rc = elfcorehdr_alloc(&elfcorehdr_addr, &elfcorehdr_size);
992 * If elfcorehdr= has been passed in cmdline or created in 2nd kernel,
993 * then capture the dump.
995 if (!(is_vmcore_usable()))
997 rc = parse_crash_elf_headers();
999 pr_warn("Kdump: vmcore not initialized\n");
1002 elfcorehdr_free(elfcorehdr_addr);
1003 elfcorehdr_addr = ELFCORE_ADDR_ERR;
1005 proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
1007 proc_vmcore->size = vmcore_size;
1010 module_init(vmcore_init)
1012 /* Cleanup function for vmcore module. */
1013 void vmcore_cleanup(void)
1015 struct list_head *pos, *next;
1018 proc_remove(proc_vmcore);
1022 /* clear the vmcore list. */
1023 list_for_each_safe(pos, next, &vmcore_list) {
1026 m = list_entry(pos, struct vmcore, list);
1032 EXPORT_SYMBOL_GPL(vmcore_cleanup);