[linux.git] / fs / proc / vmcore.c

/*
 *	fs/proc/vmcore.c Interface for accessing the crash
 * 				 dump from the system's previous life.
 * 	Heavily borrowed from fs/proc/kcore.c
 *	Created by: Hariprasad Nellitheertha ([email protected])
 *	Copyright (C) IBM Corporation, 2004. All rights reserved
 *
 */

#include <linux/config.h>
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/elf.h>
#include <linux/elfcore.h>
#include <linux/highmem.h>
#include <linux/bootmem.h>
#include <linux/init.h>
#include <linux/crash_dump.h>
#include <linux/list.h>
#include <asm/uaccess.h>
#include <asm/io.h>

/* List representing chunks of contiguous memory areas and their offsets in
 * vmcore file.
 */
static LIST_HEAD(vmcore_list);

/* Stores the pointer to the buffer containing kernel elf core headers. */
static char *elfcorebuf;
static size_t elfcorebuf_sz;

/* Total size of vmcore file. */
static u64 vmcore_size;

/* Stores the physical address of elf header of crash image. */
unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;

struct proc_dir_entry *proc_vmcore = NULL;

/* Reads a page from the oldmem device from given offset. */
static ssize_t read_from_oldmem(char *buf, size_t count,
				u64 *ppos, int userbuf)
{
	unsigned long pfn, offset;
	size_t nr_bytes;
	ssize_t read = 0, tmp;

	if (!count)
		return 0;

	offset = (unsigned long)(*ppos % PAGE_SIZE);
	pfn = (unsigned long)(*ppos / PAGE_SIZE);
	if (pfn > saved_max_pfn)
		return -EINVAL;

	do {
		if (count > (PAGE_SIZE - offset))
			nr_bytes = PAGE_SIZE - offset;
		else
			nr_bytes = count;

		tmp = copy_oldmem_page(pfn, buf, nr_bytes, offset, userbuf);
		if (tmp < 0)
			return tmp;
		*ppos += nr_bytes;
		count -= nr_bytes;
		buf += nr_bytes;
		read += nr_bytes;
		++pfn;
		offset = 0;
	} while (count);

	return read;
}

/* Maps vmcore file offset to respective physical address in memroy. */
static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list,
					struct vmcore **m_ptr)
{
	struct vmcore *m;
	u64 paddr;

	list_for_each_entry(m, vc_list, list) {
		u64 start, end;
		start = m->offset;
		end = m->offset + m->size - 1;
		if (offset >= start && offset <= end) {
			paddr = m->paddr + offset - start;
			*m_ptr = m;
			return paddr;
		}
	}
	*m_ptr = NULL;
	return 0;
}

/* Read from the ELF header and then the crash dump. On error, negative value is
 * returned otherwise number of bytes read are returned.
 */
static ssize_t read_vmcore(struct file *file, char __user *buffer,
				size_t buflen, loff_t *fpos)
{
	ssize_t acc = 0, tmp;
	size_t tsz;
	u64 start, nr_bytes;
	struct vmcore *curr_m = NULL;

	if (buflen == 0 || *fpos >= vmcore_size)
		return 0;

	/* trim buflen to not go beyond EOF */
	if (buflen > vmcore_size - *fpos)
		buflen = vmcore_size - *fpos;

	/* Read ELF core header */
	if (*fpos < elfcorebuf_sz) {
		tsz = elfcorebuf_sz - *fpos;
		if (buflen < tsz)
			tsz = buflen;
		if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
			return -EFAULT;
		buflen -= tsz;
		*fpos += tsz;
		buffer += tsz;
		acc += tsz;

		/* leave now if filled buffer already */
		if (buflen == 0)
			return acc;
	}

	start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m);
	if (!curr_m)
        	return -EINVAL;
	if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
		tsz = buflen;

	/* Calculate left bytes in current memory segment. */
	nr_bytes = (curr_m->size - (start - curr_m->paddr));
	if (tsz > nr_bytes)
		tsz = nr_bytes;

	while (buflen) {
		tmp = read_from_oldmem(buffer, tsz, &start, 1);
		if (tmp < 0)
			return tmp;
		buflen -= tsz;
		*fpos += tsz;
		buffer += tsz;
		acc += tsz;
		if (start >= (curr_m->paddr + curr_m->size)) {
			if (curr_m->list.next == &vmcore_list)
				return acc;	/*EOF*/
			curr_m = list_entry(curr_m->list.next,
						struct vmcore, list);
			start = curr_m->paddr;
		}
		if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
			tsz = buflen;
		/* Calculate left bytes in current memory segment. */
		nr_bytes = (curr_m->size - (start - curr_m->paddr));
		if (tsz > nr_bytes)
			tsz = nr_bytes;
	}
	return acc;
}

static int open_vmcore(struct inode *inode, struct file *filp)
{
	return 0;
}

const struct file_operations proc_vmcore_operations = {
	.read		= read_vmcore,
	.open		= open_vmcore,
};

static struct vmcore* __init get_new_element(void)
{
	struct vmcore *p;

	p = kmalloc(sizeof(*p), GFP_KERNEL);
	if (p)
		memset(p, 0, sizeof(*p));
	return p;
}

static u64 __init get_vmcore_size_elf64(char *elfptr)
{
	int i;
	u64 size;
	Elf64_Ehdr *ehdr_ptr;
	Elf64_Phdr *phdr_ptr;

	ehdr_ptr = (Elf64_Ehdr *)elfptr;
	phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
	size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr));
	for (i = 0; i < ehdr_ptr->e_phnum; i++) {
		size += phdr_ptr->p_memsz;
		phdr_ptr++;
	}
	return size;
}

static u64 __init get_vmcore_size_elf32(char *elfptr)
{
	int i;
	u64 size;
	Elf32_Ehdr *ehdr_ptr;
	Elf32_Phdr *phdr_ptr;

	ehdr_ptr = (Elf32_Ehdr *)elfptr;
	phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
	size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
	for (i = 0; i < ehdr_ptr->e_phnum; i++) {
		size += phdr_ptr->p_memsz;
		phdr_ptr++;
	}
	return size;
}

/* Merges all the PT_NOTE headers into one. */
static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
						struct list_head *vc_list)
{
	int i, nr_ptnote=0, rc=0;
	char *tmp;
	Elf64_Ehdr *ehdr_ptr;
	Elf64_Phdr phdr, *phdr_ptr;
	Elf64_Nhdr *nhdr_ptr;
	u64 phdr_sz = 0, note_off;

	ehdr_ptr = (Elf64_Ehdr *)elfptr;
	phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
		int j;
		void *notes_section;
		struct vmcore *new;
		u64 offset, max_sz, sz, real_sz = 0;
		if (phdr_ptr->p_type != PT_NOTE)
			continue;
		nr_ptnote++;
		max_sz = phdr_ptr->p_memsz;
		offset = phdr_ptr->p_offset;
		notes_section = kmalloc(max_sz, GFP_KERNEL);
		if (!notes_section)
			return -ENOMEM;
		rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
		if (rc < 0) {
			kfree(notes_section);
			return rc;
		}
		nhdr_ptr = notes_section;
		for (j = 0; j < max_sz; j += sz) {
			if (nhdr_ptr->n_namesz == 0)
				break;
			sz = sizeof(Elf64_Nhdr) +
				((nhdr_ptr->n_namesz + 3) & ~3) +
				((nhdr_ptr->n_descsz + 3) & ~3);
			real_sz += sz;
			nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
		}

		/* Add this contiguous chunk of notes section to vmcore list.*/
		new = get_new_element();
		if (!new) {
			kfree(notes_section);
			return -ENOMEM;
		}
		new->paddr = phdr_ptr->p_offset;
		new->size = real_sz;
		list_add_tail(&new->list, vc_list);
		phdr_sz += real_sz;
		kfree(notes_section);
	}

	/* Prepare merged PT_NOTE program header. */
	phdr.p_type    = PT_NOTE;
	phdr.p_flags   = 0;
	note_off = sizeof(Elf64_Ehdr) +
			(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
	phdr.p_offset  = note_off;
	phdr.p_vaddr   = phdr.p_paddr = 0;
	phdr.p_filesz  = phdr.p_memsz = phdr_sz;
	phdr.p_align   = 0;

	/* Add merged PT_NOTE program header*/
	tmp = elfptr + sizeof(Elf64_Ehdr);
	memcpy(tmp, &phdr, sizeof(phdr));
	tmp += sizeof(phdr);

	/* Remove unwanted PT_NOTE program headers. */
	i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
	*elfsz = *elfsz - i;
	memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));

	/* Modify e_phnum to reflect merged headers. */
	ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;

	return 0;
}

/* Merges all the PT_NOTE headers into one. */
static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
						struct list_head *vc_list)
{
	int i, nr_ptnote=0, rc=0;
	char *tmp;
	Elf32_Ehdr *ehdr_ptr;
	Elf32_Phdr phdr, *phdr_ptr;
	Elf32_Nhdr *nhdr_ptr;
	u64 phdr_sz = 0, note_off;

	ehdr_ptr = (Elf32_Ehdr *)elfptr;
	phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
		int j;
		void *notes_section;
		struct vmcore *new;
		u64 offset, max_sz, sz, real_sz = 0;
		if (phdr_ptr->p_type != PT_NOTE)
			continue;
		nr_ptnote++;
		max_sz = phdr_ptr->p_memsz;
		offset = phdr_ptr->p_offset;
		notes_section = kmalloc(max_sz, GFP_KERNEL);
		if (!notes_section)
			return -ENOMEM;
		rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
		if (rc < 0) {
			kfree(notes_section);
			return rc;
		}
		nhdr_ptr = notes_section;
		for (j = 0; j < max_sz; j += sz) {
			if (nhdr_ptr->n_namesz == 0)
				break;
			sz = sizeof(Elf32_Nhdr) +
				((nhdr_ptr->n_namesz + 3) & ~3) +
				((nhdr_ptr->n_descsz + 3) & ~3);
			real_sz += sz;
			nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
		}

		/* Add this contiguous chunk of notes section to vmcore list.*/
		new = get_new_element();
		if (!new) {
			kfree(notes_section);
			return -ENOMEM;
		}
		new->paddr = phdr_ptr->p_offset;
		new->size = real_sz;
		list_add_tail(&new->list, vc_list);
		phdr_sz += real_sz;
		kfree(notes_section);
	}

	/* Prepare merged PT_NOTE program header. */
	phdr.p_type    = PT_NOTE;
	phdr.p_flags   = 0;
	note_off = sizeof(Elf32_Ehdr) +
			(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
	phdr.p_offset  = note_off;
	phdr.p_vaddr   = phdr.p_paddr = 0;
	phdr.p_filesz  = phdr.p_memsz = phdr_sz;
	phdr.p_align   = 0;

	/* Add merged PT_NOTE program header*/
	tmp = elfptr + sizeof(Elf32_Ehdr);
	memcpy(tmp, &phdr, sizeof(phdr));
	tmp += sizeof(phdr);

	/* Remove unwanted PT_NOTE program headers. */
	i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
	*elfsz = *elfsz - i;
	memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));

	/* Modify e_phnum to reflect merged headers. */
	ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;

	return 0;
}

/* Add memory chunks represented by program headers to vmcore list. Also update
 * the new offset fields of exported program headers. */
static int __init process_ptload_program_headers_elf64(char *elfptr,
						size_t elfsz,
						struct list_head *vc_list)
{
	int i;
	Elf64_Ehdr *ehdr_ptr;
	Elf64_Phdr *phdr_ptr;
	loff_t vmcore_off;
	struct vmcore *new;

	ehdr_ptr = (Elf64_Ehdr *)elfptr;
	phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */

	/* First program header is PT_NOTE header. */
	vmcore_off = sizeof(Elf64_Ehdr) +
			(ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
			phdr_ptr->p_memsz; /* Note sections */

	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
		if (phdr_ptr->p_type != PT_LOAD)
			continue;

		/* Add this contiguous chunk of memory to vmcore list.*/
		new = get_new_element();
		if (!new)
			return -ENOMEM;
		new->paddr = phdr_ptr->p_offset;
		new->size = phdr_ptr->p_memsz;
		list_add_tail(&new->list, vc_list);

		/* Update the program header offset. */
		phdr_ptr->p_offset = vmcore_off;
		vmcore_off = vmcore_off + phdr_ptr->p_memsz;
	}
	return 0;
}

static int __init process_ptload_program_headers_elf32(char *elfptr,
						size_t elfsz,
						struct list_head *vc_list)
{
	int i;
	Elf32_Ehdr *ehdr_ptr;
	Elf32_Phdr *phdr_ptr;
	loff_t vmcore_off;
	struct vmcore *new;

	ehdr_ptr = (Elf32_Ehdr *)elfptr;
	phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */

	/* First program header is PT_NOTE header. */
	vmcore_off = sizeof(Elf32_Ehdr) +
			(ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
			phdr_ptr->p_memsz; /* Note sections */

	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
		if (phdr_ptr->p_type != PT_LOAD)
			continue;

		/* Add this contiguous chunk of memory to vmcore list.*/
		new = get_new_element();
		if (!new)
			return -ENOMEM;
		new->paddr = phdr_ptr->p_offset;
		new->size = phdr_ptr->p_memsz;
		list_add_tail(&new->list, vc_list);

		/* Update the program header offset */
		phdr_ptr->p_offset = vmcore_off;
		vmcore_off = vmcore_off + phdr_ptr->p_memsz;
	}
	return 0;
}

/* Sets offset fields of vmcore elements. */
static void __init set_vmcore_list_offsets_elf64(char *elfptr,
						struct list_head *vc_list)
{
	loff_t vmcore_off;
	Elf64_Ehdr *ehdr_ptr;
	struct vmcore *m;

	ehdr_ptr = (Elf64_Ehdr *)elfptr;

	/* Skip Elf header and program headers. */
	vmcore_off = sizeof(Elf64_Ehdr) +
			(ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr);

	list_for_each_entry(m, vc_list, list) {
		m->offset = vmcore_off;
		vmcore_off += m->size;
	}
}

/* Sets offset fields of vmcore elements. */
static void __init set_vmcore_list_offsets_elf32(char *elfptr,
						struct list_head *vc_list)
{
	loff_t vmcore_off;
	Elf32_Ehdr *ehdr_ptr;
	struct vmcore *m;

	ehdr_ptr = (Elf32_Ehdr *)elfptr;

	/* Skip Elf header and program headers. */
	vmcore_off = sizeof(Elf32_Ehdr) +
			(ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);

	list_for_each_entry(m, vc_list, list) {
		m->offset = vmcore_off;
		vmcore_off += m->size;
	}
}

static int __init parse_crash_elf64_headers(void)
{
	int rc=0;
	Elf64_Ehdr ehdr;
	u64 addr;

	addr = elfcorehdr_addr;

	/* Read Elf header */
	rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0);
	if (rc < 0)
		return rc;

	/* Do some basic Verification. */
	if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
		(ehdr.e_type != ET_CORE) ||
		!elf_check_arch(&ehdr) ||
		ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
		ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
		ehdr.e_version != EV_CURRENT ||
		ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
		ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
		ehdr.e_phnum == 0) {
		printk(KERN_WARNING "Warning: Core image elf header is not"
					"sane\n");
		return -EINVAL;
	}

	/* Read in all elf headers. */
	elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr);
	elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
	if (!elfcorebuf)
		return -ENOMEM;
	addr = elfcorehdr_addr;
	rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
	if (rc < 0) {
		kfree(elfcorebuf);
		return rc;
	}

	/* Merge all PT_NOTE headers into one. */
	rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
	if (rc) {
		kfree(elfcorebuf);
		return rc;
	}
	rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
							&vmcore_list);
	if (rc) {
		kfree(elfcorebuf);
		return rc;
	}
	set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list);
	return 0;
}

static int __init parse_crash_elf32_headers(void)
{
	int rc=0;
	Elf32_Ehdr ehdr;
	u64 addr;

	addr = elfcorehdr_addr;

	/* Read Elf header */
	rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
	if (rc < 0)
		return rc;

	/* Do some basic Verification. */
	if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
		(ehdr.e_type != ET_CORE) ||
		!elf_check_arch(&ehdr) ||
		ehdr.e_ident[EI_CLASS] != ELFCLASS32||
		ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
		ehdr.e_version != EV_CURRENT ||
		ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
		ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
		ehdr.e_phnum == 0) {
		printk(KERN_WARNING "Warning: Core image elf header is not"
					"sane\n");
		return -EINVAL;
	}

	/* Read in all elf headers. */
	elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
	elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
	if (!elfcorebuf)
		return -ENOMEM;
	addr = elfcorehdr_addr;
	rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
	if (rc < 0) {
		kfree(elfcorebuf);
		return rc;
	}

	/* Merge all PT_NOTE headers into one. */
	rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
	if (rc) {
		kfree(elfcorebuf);
		return rc;
	}
	rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
								&vmcore_list);
	if (rc) {
		kfree(elfcorebuf);
		return rc;
	}
	set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list);
	return 0;
}

static int __init parse_crash_elf_headers(void)
{
	unsigned char e_ident[EI_NIDENT];
	u64 addr;
	int rc=0;

	addr = elfcorehdr_addr;
	rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0);
	if (rc < 0)
		return rc;
	if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
		printk(KERN_WARNING "Warning: Core image elf header"
					" not found\n");
		return -EINVAL;
	}

	if (e_ident[EI_CLASS] == ELFCLASS64) {
		rc = parse_crash_elf64_headers();
		if (rc)
			return rc;

		/* Determine vmcore size. */
		vmcore_size = get_vmcore_size_elf64(elfcorebuf);
	} else if (e_ident[EI_CLASS] == ELFCLASS32) {
		rc = parse_crash_elf32_headers();
		if (rc)
			return rc;

		/* Determine vmcore size. */
		vmcore_size = get_vmcore_size_elf32(elfcorebuf);
	} else {
		printk(KERN_WARNING "Warning: Core image elf header is not"
					" sane\n");
		return -EINVAL;
	}
	return 0;
}

/* Init function for vmcore module. */
static int __init vmcore_init(void)
{
	int rc = 0;

	/* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
	if (!(elfcorehdr_addr < ELFCORE_ADDR_MAX))
		return rc;
	rc = parse_crash_elf_headers();
	if (rc) {
		printk(KERN_WARNING "Kdump: vmcore not initialized\n");
		return rc;
	}

	/* Initialize /proc/vmcore size if proc is already up. */
	if (proc_vmcore)
		proc_vmcore->size = vmcore_size;
	return 0;
}
module_init(vmcore_init)
Commit	Line	Data
666bfddb VG	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 ([email protected])
	6	* Copyright (C) IBM Corporation, 2004. All rights reserved
	7	*
	8	*/
	9
	10	#include <linux/config.h>
	11	#include <linux/mm.h>
	12	#include <linux/proc_fs.h>
	13	#include <linux/user.h>
	14	#include <linux/a.out.h>
	15	#include <linux/elf.h>
	16	#include <linux/elfcore.h>
666bfddb VG	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	*/
	28	static LIST_HEAD(vmcore_list);
	29
	30	/* Stores the pointer to the buffer containing kernel elf core headers. */
	31	static char *elfcorebuf;
	32	static size_t elfcorebuf_sz;
	33
	34	/* Total size of vmcore file. */
	35	static u64 vmcore_size;
	36
4ae362be VG	37	/* Stores the physical address of elf header of crash image. */
	38	unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
	39
666bfddb VG	40	struct proc_dir_entry *proc_vmcore = NULL;
	41
	42	/* Reads a page from the oldmem device from given offset. */
	43	static ssize_t read_from_oldmem(char *buf, size_t count,
9e9e3941	44	u64 *ppos, int userbuf)
666bfddb VG	45	{
	46	unsigned long pfn, offset;
	47	size_t nr_bytes;
	48	ssize_t read = 0, tmp;
	49
	50	if (!count)
	51	return 0;
	52
	53	offset = (unsigned long)(*ppos % PAGE_SIZE);
	54	pfn = (unsigned long)(*ppos / PAGE_SIZE);
	55	if (pfn > saved_max_pfn)
	56	return -EINVAL;
	57
	58	do {
	59	if (count > (PAGE_SIZE - offset))
	60	nr_bytes = PAGE_SIZE - offset;
	61	else
	62	nr_bytes = count;
	63
	64	tmp = copy_oldmem_page(pfn, buf, nr_bytes, offset, userbuf);
	65	if (tmp < 0)
	66	return tmp;
	67	*ppos += nr_bytes;
	68	count -= nr_bytes;
	69	buf += nr_bytes;
	70	read += nr_bytes;
	71	++pfn;
	72	offset = 0;
	73	} while (count);
	74
	75	return read;
	76	}
	77
	78	/* Maps vmcore file offset to respective physical address in memroy. */
	79	static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list,
	80	struct vmcore **m_ptr)
	81	{
	82	struct vmcore *m;
	83	u64 paddr;
	84
	85	list_for_each_entry(m, vc_list, list) {
	86	u64 start, end;
	87	start = m->offset;
	88	end = m->offset + m->size - 1;
	89	if (offset >= start && offset <= end) {
	90	paddr = m->paddr + offset - start;
	91	*m_ptr = m;
	92	return paddr;
	93	}
	94	}
	95	*m_ptr = NULL;
	96	return 0;
	97	}
	98
	99	/* Read from the ELF header and then the crash dump. On error, negative value is
	100	* returned otherwise number of bytes read are returned.
	101	*/
	102	static ssize_t read_vmcore(struct file file, char __user buffer,
	103	size_t buflen, loff_t *fpos)
	104	{
	105	ssize_t acc = 0, tmp;
80e8ff63 VG	106	size_t tsz;
80e8ff63 VG	107	u64 start, nr_bytes;
666bfddb VG	108	struct vmcore *curr_m = NULL;
	109
	110	if (buflen == 0 \|\| *fpos >= vmcore_size)
	111	return 0;
	112
	113	/* trim buflen to not go beyond EOF */
	114	if (buflen > vmcore_size - *fpos)
	115	buflen = vmcore_size - *fpos;
	116
	117	/* Read ELF core header */
	118	if (*fpos < elfcorebuf_sz) {
	119	tsz = elfcorebuf_sz - *fpos;
	120	if (buflen < tsz)
	121	tsz = buflen;
	122	if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
	123	return -EFAULT;
	124	buflen -= tsz;
	125	*fpos += tsz;
	126	buffer += tsz;
	127	acc += tsz;
	128
	129	/* leave now if filled buffer already */
	130	if (buflen == 0)
	131	return acc;
	132	}
	133
	134	start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m);
	135	if (!curr_m)
	136	return -EINVAL;
	137	if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
	138	tsz = buflen;
	139
	140	/* Calculate left bytes in current memory segment. */
	141	nr_bytes = (curr_m->size - (start - curr_m->paddr));
	142	if (tsz > nr_bytes)
	143	tsz = nr_bytes;
	144
	145	while (buflen) {
	146	tmp = read_from_oldmem(buffer, tsz, &start, 1);
	147	if (tmp < 0)
	148	return tmp;
	149	buflen -= tsz;
	150	*fpos += tsz;
	151	buffer += tsz;
	152	acc += tsz;
	153	if (start >= (curr_m->paddr + curr_m->size)) {
	154	if (curr_m->list.next == &vmcore_list)
	155	return acc; /EOF/
	156	curr_m = list_entry(curr_m->list.next,
	157	struct vmcore, list);
	158	start = curr_m->paddr;
	159	}
	160	if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
	161	tsz = buflen;
	162	/* Calculate left bytes in current memory segment. */
	163	nr_bytes = (curr_m->size - (start - curr_m->paddr));
	164	if (tsz > nr_bytes)
	165	tsz = nr_bytes;
	166	}
	167	return acc;
	168	}
	169
	170	static int open_vmcore(struct inode inode, struct file filp)
	171	{
172	return 0;
173	}
174
4b6f5d20	175	const struct file_operations proc_vmcore_operations = {
666bfddb VG	176	.read = read_vmcore,
	177	.open = open_vmcore,
	178	};
	179
	180	static struct vmcore* __init get_new_element(void)
	181	{
	182	struct vmcore *p;
	183
	184	p = kmalloc(sizeof(*p), GFP_KERNEL);
	185	if (p)
	186	memset(p, 0, sizeof(*p));
	187	return p;
	188	}
	189
	190	static u64 __init get_vmcore_size_elf64(char *elfptr)
	191	{
	192	int i;
	193	u64 size;
	194	Elf64_Ehdr *ehdr_ptr;
	195	Elf64_Phdr *phdr_ptr;
	196
	197	ehdr_ptr = (Elf64_Ehdr *)elfptr;
	198	phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
	199	size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr));
	200	for (i = 0; i < ehdr_ptr->e_phnum; i++) {
	201	size += phdr_ptr->p_memsz;
	202	phdr_ptr++;
	203	}
	204	return size;
	205	}
	206
72658e9d VG	207	static u64 __init get_vmcore_size_elf32(char *elfptr)
	208	{
	209	int i;
	210	u64 size;
	211	Elf32_Ehdr *ehdr_ptr;
	212	Elf32_Phdr *phdr_ptr;
	213
	214	ehdr_ptr = (Elf32_Ehdr *)elfptr;
	215	phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
	216	size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
	217	for (i = 0; i < ehdr_ptr->e_phnum; i++) {
	218	size += phdr_ptr->p_memsz;
	219	phdr_ptr++;
	220	}
	221	return size;
	222	}
	223
666bfddb VG	224	/* Merges all the PT_NOTE headers into one. */
	225	static int __init merge_note_headers_elf64(char elfptr, size_t elfsz,
	226	struct list_head *vc_list)
	227	{
	228	int i, nr_ptnote=0, rc=0;
	229	char *tmp;
	230	Elf64_Ehdr *ehdr_ptr;
	231	Elf64_Phdr phdr, *phdr_ptr;
	232	Elf64_Nhdr *nhdr_ptr;
	233	u64 phdr_sz = 0, note_off;
	234
	235	ehdr_ptr = (Elf64_Ehdr *)elfptr;
	236	phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
	237	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
	238	int j;
	239	void *notes_section;
	240	struct vmcore *new;
	241	u64 offset, max_sz, sz, real_sz = 0;
	242	if (phdr_ptr->p_type != PT_NOTE)
	243	continue;
	244	nr_ptnote++;
	245	max_sz = phdr_ptr->p_memsz;
	246	offset = phdr_ptr->p_offset;
	247	notes_section = kmalloc(max_sz, GFP_KERNEL);
	248	if (!notes_section)
	249	return -ENOMEM;
	250	rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
	251	if (rc < 0) {
	252	kfree(notes_section);
	253	return rc;
	254	}
	255	nhdr_ptr = notes_section;
	256	for (j = 0; j < max_sz; j += sz) {
	257	if (nhdr_ptr->n_namesz == 0)
	258	break;
	259	sz = sizeof(Elf64_Nhdr) +
	260	((nhdr_ptr->n_namesz + 3) & ~3) +
	261	((nhdr_ptr->n_descsz + 3) & ~3);
	262	real_sz += sz;
	263	nhdr_ptr = (Elf64_Nhdr)((char)nhdr_ptr + sz);
	264	}
	265
	266	/* Add this contiguous chunk of notes section to vmcore list.*/
	267	new = get_new_element();
	268	if (!new) {
	269	kfree(notes_section);
	270	return -ENOMEM;
	271	}
	272	new->paddr = phdr_ptr->p_offset;
	273	new->size = real_sz;
	274	list_add_tail(&new->list, vc_list);
	275	phdr_sz += real_sz;
	276	kfree(notes_section);
	277	}
	278
	279	/* Prepare merged PT_NOTE program header. */
	280	phdr.p_type = PT_NOTE;
	281	phdr.p_flags = 0;
	282	note_off = sizeof(Elf64_Ehdr) +
	283	(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
	284	phdr.p_offset = note_off;
	285	phdr.p_vaddr = phdr.p_paddr = 0;
	286	phdr.p_filesz = phdr.p_memsz = phdr_sz;
	287	phdr.p_align = 0;
288
289	/* Add merged PT_NOTE program header*/
290	tmp = elfptr + sizeof(Elf64_Ehdr);
291	memcpy(tmp, &phdr, sizeof(phdr));
292	tmp += sizeof(phdr);
293
294	/* Remove unwanted PT_NOTE program headers. */
295	i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
296	elfsz = elfsz - i;
297	memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
298
299	/* Modify e_phnum to reflect merged headers. */
300	ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
301
302	return 0;
303	}
304
72658e9d VG	305	/* Merges all the PT_NOTE headers into one. */
	306	static int __init merge_note_headers_elf32(char elfptr, size_t elfsz,
	307	struct list_head *vc_list)
	308	{
	309	int i, nr_ptnote=0, rc=0;
	310	char *tmp;
	311	Elf32_Ehdr *ehdr_ptr;
	312	Elf32_Phdr phdr, *phdr_ptr;
	313	Elf32_Nhdr *nhdr_ptr;
	314	u64 phdr_sz = 0, note_off;
	315
	316	ehdr_ptr = (Elf32_Ehdr *)elfptr;
	317	phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
	318	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
	319	int j;
	320	void *notes_section;
	321	struct vmcore *new;
	322	u64 offset, max_sz, sz, real_sz = 0;
	323	if (phdr_ptr->p_type != PT_NOTE)
	324	continue;
	325	nr_ptnote++;
	326	max_sz = phdr_ptr->p_memsz;
	327	offset = phdr_ptr->p_offset;
	328	notes_section = kmalloc(max_sz, GFP_KERNEL);
	329	if (!notes_section)
	330	return -ENOMEM;
	331	rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
	332	if (rc < 0) {
	333	kfree(notes_section);
	334	return rc;
	335	}
	336	nhdr_ptr = notes_section;
	337	for (j = 0; j < max_sz; j += sz) {
	338	if (nhdr_ptr->n_namesz == 0)
	339	break;
	340	sz = sizeof(Elf32_Nhdr) +
	341	((nhdr_ptr->n_namesz + 3) & ~3) +
	342	((nhdr_ptr->n_descsz + 3) & ~3);
	343	real_sz += sz;
	344	nhdr_ptr = (Elf32_Nhdr)((char)nhdr_ptr + sz);
	345	}
	346
	347	/* Add this contiguous chunk of notes section to vmcore list.*/
	348	new = get_new_element();
	349	if (!new) {
	350	kfree(notes_section);
	351	return -ENOMEM;
	352	}
	353	new->paddr = phdr_ptr->p_offset;
	354	new->size = real_sz;
	355	list_add_tail(&new->list, vc_list);
	356	phdr_sz += real_sz;
	357	kfree(notes_section);
	358	}
	359
	360	/* Prepare merged PT_NOTE program header. */
	361	phdr.p_type = PT_NOTE;
	362	phdr.p_flags = 0;
	363	note_off = sizeof(Elf32_Ehdr) +
	364	(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
	365	phdr.p_offset = note_off;
	366	phdr.p_vaddr = phdr.p_paddr = 0;
	367	phdr.p_filesz = phdr.p_memsz = phdr_sz;
	368	phdr.p_align = 0;
369
370	/* Add merged PT_NOTE program header*/
371	tmp = elfptr + sizeof(Elf32_Ehdr);
372	memcpy(tmp, &phdr, sizeof(phdr));
373	tmp += sizeof(phdr);
374
375	/* Remove unwanted PT_NOTE program headers. */
376	i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
377	elfsz = elfsz - i;
378	memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
379
380	/* Modify e_phnum to reflect merged headers. */
381	ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
382
383	return 0;
384	}
385
666bfddb VG	386	/* Add memory chunks represented by program headers to vmcore list. Also update
	387	* the new offset fields of exported program headers. */
	388	static int __init process_ptload_program_headers_elf64(char *elfptr,
	389	size_t elfsz,
	390	struct list_head *vc_list)
	391	{
	392	int i;
	393	Elf64_Ehdr *ehdr_ptr;
	394	Elf64_Phdr *phdr_ptr;
	395	loff_t vmcore_off;
	396	struct vmcore *new;
	397
	398	ehdr_ptr = (Elf64_Ehdr *)elfptr;
	399	phdr_ptr = (Elf64_Phdr)(elfptr + sizeof(Elf64_Ehdr)); / PT_NOTE hdr */
	400
	401	/* First program header is PT_NOTE header. */
	402	vmcore_off = sizeof(Elf64_Ehdr) +
	403	(ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
	404	phdr_ptr->p_memsz; /* Note sections */
	405
	406	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
	407	if (phdr_ptr->p_type != PT_LOAD)
	408	continue;
	409
	410	/* Add this contiguous chunk of memory to vmcore list.*/
	411	new = get_new_element();
	412	if (!new)
	413	return -ENOMEM;
	414	new->paddr = phdr_ptr->p_offset;
	415	new->size = phdr_ptr->p_memsz;
	416	list_add_tail(&new->list, vc_list);
	417
	418	/* Update the program header offset. */
	419	phdr_ptr->p_offset = vmcore_off;
	420	vmcore_off = vmcore_off + phdr_ptr->p_memsz;
	421	}
	422	return 0;
	423	}
	424
72658e9d VG	425	static int __init process_ptload_program_headers_elf32(char *elfptr,
	426	size_t elfsz,
	427	struct list_head *vc_list)
	428	{
	429	int i;
	430	Elf32_Ehdr *ehdr_ptr;
	431	Elf32_Phdr *phdr_ptr;
	432	loff_t vmcore_off;
	433	struct vmcore *new;
	434
	435	ehdr_ptr = (Elf32_Ehdr *)elfptr;
	436	phdr_ptr = (Elf32_Phdr)(elfptr + sizeof(Elf32_Ehdr)); / PT_NOTE hdr */
	437
	438	/* First program header is PT_NOTE header. */
	439	vmcore_off = sizeof(Elf32_Ehdr) +
	440	(ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
	441	phdr_ptr->p_memsz; /* Note sections */
	442
	443	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
	444	if (phdr_ptr->p_type != PT_LOAD)
	445	continue;
	446
	447	/* Add this contiguous chunk of memory to vmcore list.*/
	448	new = get_new_element();
	449	if (!new)
	450	return -ENOMEM;
	451	new->paddr = phdr_ptr->p_offset;
	452	new->size = phdr_ptr->p_memsz;
	453	list_add_tail(&new->list, vc_list);
	454
	455	/* Update the program header offset */
	456	phdr_ptr->p_offset = vmcore_off;
	457	vmcore_off = vmcore_off + phdr_ptr->p_memsz;
	458	}
	459	return 0;
	460	}
	461
666bfddb VG	462	/* Sets offset fields of vmcore elements. */
	463	static void __init set_vmcore_list_offsets_elf64(char *elfptr,
	464	struct list_head *vc_list)
	465	{
	466	loff_t vmcore_off;
	467	Elf64_Ehdr *ehdr_ptr;
	468	struct vmcore *m;
	469
	470	ehdr_ptr = (Elf64_Ehdr *)elfptr;
	471
	472	/* Skip Elf header and program headers. */
	473	vmcore_off = sizeof(Elf64_Ehdr) +
	474	(ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr);
	475
	476	list_for_each_entry(m, vc_list, list) {
	477	m->offset = vmcore_off;
	478	vmcore_off += m->size;
	479	}
	480	}
	481
72658e9d VG	482	/* Sets offset fields of vmcore elements. */
	483	static void __init set_vmcore_list_offsets_elf32(char *elfptr,
	484	struct list_head *vc_list)
	485	{
	486	loff_t vmcore_off;
	487	Elf32_Ehdr *ehdr_ptr;
	488	struct vmcore *m;
	489
	490	ehdr_ptr = (Elf32_Ehdr *)elfptr;
	491
	492	/* Skip Elf header and program headers. */
	493	vmcore_off = sizeof(Elf32_Ehdr) +
	494	(ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);
	495
	496	list_for_each_entry(m, vc_list, list) {
	497	m->offset = vmcore_off;
	498	vmcore_off += m->size;
	499	}
	500	}
	501
666bfddb VG	502	static int __init parse_crash_elf64_headers(void)
	503	{
	504	int rc=0;
	505	Elf64_Ehdr ehdr;
	506	u64 addr;
	507
	508	addr = elfcorehdr_addr;
	509
	510	/* Read Elf header */
	511	rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0);
	512	if (rc < 0)
	513	return rc;
	514
	515	/* Do some basic Verification. */
	516	if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 \|\|
	517	(ehdr.e_type != ET_CORE) \|\|
	518	!elf_check_arch(&ehdr) \|\|
	519	ehdr.e_ident[EI_CLASS] != ELFCLASS64 \|\|
	520	ehdr.e_ident[EI_VERSION] != EV_CURRENT \|\|
	521	ehdr.e_version != EV_CURRENT \|\|
	522	ehdr.e_ehsize != sizeof(Elf64_Ehdr) \|\|
	523	ehdr.e_phentsize != sizeof(Elf64_Phdr) \|\|
	524	ehdr.e_phnum == 0) {
	525	printk(KERN_WARNING "Warning: Core image elf header is not"
	526	"sane\n");
	527	return -EINVAL;
	528	}
	529
	530	/* Read in all elf headers. */
	531	elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr);
	532	elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
	533	if (!elfcorebuf)
	534	return -ENOMEM;
	535	addr = elfcorehdr_addr;
	536	rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
	537	if (rc < 0) {
	538	kfree(elfcorebuf);
	539	return rc;
	540	}
	541
	542	/* Merge all PT_NOTE headers into one. */
	543	rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
	544	if (rc) {
	545	kfree(elfcorebuf);
	546	return rc;
	547	}
	548	rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
	549	&vmcore_list);
	550	if (rc) {
	551	kfree(elfcorebuf);
	552	return rc;
	553	}
	554	set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list);
	555	return 0;
	556	}
	557
72658e9d VG	558	static int __init parse_crash_elf32_headers(void)
	559	{
	560	int rc=0;
	561	Elf32_Ehdr ehdr;
	562	u64 addr;
	563
	564	addr = elfcorehdr_addr;
	565
	566	/* Read Elf header */
	567	rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
	568	if (rc < 0)
	569	return rc;
	570
	571	/* Do some basic Verification. */
	572	if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 \|\|
	573	(ehdr.e_type != ET_CORE) \|\|
	574	!elf_check_arch(&ehdr) \|\|
	575	ehdr.e_ident[EI_CLASS] != ELFCLASS32\|\|
	576	ehdr.e_ident[EI_VERSION] != EV_CURRENT \|\|
	577	ehdr.e_version != EV_CURRENT \|\|
	578	ehdr.e_ehsize != sizeof(Elf32_Ehdr) \|\|
	579	ehdr.e_phentsize != sizeof(Elf32_Phdr) \|\|
	580	ehdr.e_phnum == 0) {
	581	printk(KERN_WARNING "Warning: Core image elf header is not"
	582	"sane\n");
	583	return -EINVAL;
	584	}
	585
	586	/* Read in all elf headers. */
	587	elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
	588	elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
	589	if (!elfcorebuf)
	590	return -ENOMEM;
	591	addr = elfcorehdr_addr;
	592	rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
	593	if (rc < 0) {
	594	kfree(elfcorebuf);
	595	return rc;
	596	}
	597
	598	/* Merge all PT_NOTE headers into one. */
	599	rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
	600	if (rc) {
	601	kfree(elfcorebuf);
	602	return rc;
	603	}
	604	rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
	605	&vmcore_list);
	606	if (rc) {
	607	kfree(elfcorebuf);
	608	return rc;
	609	}
	610	set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list);
	611	return 0;
	612	}
	613
666bfddb VG	614	static int __init parse_crash_elf_headers(void)
	615	{
	616	unsigned char e_ident[EI_NIDENT];
	617	u64 addr;
	618	int rc=0;
	619
	620	addr = elfcorehdr_addr;
	621	rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0);
	622	if (rc < 0)
	623	return rc;
	624	if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
	625	printk(KERN_WARNING "Warning: Core image elf header"
	626	" not found\n");
	627	return -EINVAL;
	628	}
	629
	630	if (e_ident[EI_CLASS] == ELFCLASS64) {
	631	rc = parse_crash_elf64_headers();
	632	if (rc)
	633	return rc;
	634
	635	/* Determine vmcore size. */
	636	vmcore_size = get_vmcore_size_elf64(elfcorebuf);
72658e9d VG	637	} else if (e_ident[EI_CLASS] == ELFCLASS32) {
	638	rc = parse_crash_elf32_headers();
	639	if (rc)
	640	return rc;
	641
	642	/* Determine vmcore size. */
	643	vmcore_size = get_vmcore_size_elf32(elfcorebuf);
666bfddb VG	644	} else {
	645	printk(KERN_WARNING "Warning: Core image elf header is not"
	646	" sane\n");
	647	return -EINVAL;
	648	}
	649	return 0;
	650	}
	651
	652	/* Init function for vmcore module. */
	653	static int __init vmcore_init(void)
	654	{
	655	int rc = 0;
	656
	657	/* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
	658	if (!(elfcorehdr_addr < ELFCORE_ADDR_MAX))
	659	return rc;
	660	rc = parse_crash_elf_headers();
	661	if (rc) {
	662	printk(KERN_WARNING "Kdump: vmcore not initialized\n");
	663	return rc;
	664	}
	665
	666	/* Initialize /proc/vmcore size if proc is already up. */
	667	if (proc_vmcore)
	668	proc_vmcore->size = vmcore_size;
	669	return 0;
	670	}
	671	module_init(vmcore_init)