1 files changed, 701 insertions, 238 deletions

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 2367fb3f70b..382aa890e22 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -8,18 +8,23 @@
  */
 
 #include <linux/mm.h>
-#include <linux/proc_fs.h>
+#include <linux/kcore.h>
 #include <linux/user.h>
 #include <linux/elf.h>
 #include <linux/elfcore.h>
+#include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/highmem.h>
+#include <linux/printk.h>
 #include <linux/bootmem.h>
 #include <linux/init.h>
 #include <linux/crash_dump.h>
 #include <linux/list.h>
+#include <linux/vmalloc.h>
+#include <linux/pagemap.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
+#include "internal.h"
 
 /* List representing chunks of contiguous memory areas and their offsets in
  * vmcore file.
@@ -29,11 +34,55 @@ static LIST_HEAD(vmcore_list);
 /* Stores the pointer to the buffer containing kernel elf core headers. */
 static char *elfcorebuf;
 static size_t elfcorebuf_sz;
+static size_t elfcorebuf_sz_orig;
+
+static char *elfnotes_buf;
+static size_t elfnotes_sz;
 
 /* Total size of vmcore file. */
 static u64 vmcore_size;
 
-static struct proc_dir_entry *proc_vmcore = NULL;
+static struct proc_dir_entry *proc_vmcore;
+
+/*
+ * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
+ * The called function has to take care of module refcounting.
+ */
+static int (*oldmem_pfn_is_ram)(unsigned long pfn);
+
+int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn))
+{
+	if (oldmem_pfn_is_ram)
+		return -EBUSY;
+	oldmem_pfn_is_ram = fn;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram);
+
+void unregister_oldmem_pfn_is_ram(void)
+{
+	oldmem_pfn_is_ram = NULL;
+	wmb();
+}
+EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram);
+
+static int pfn_is_ram(unsigned long pfn)
+{
+	int (*fn)(unsigned long pfn);
+	/* pfn is ram unless fn() checks pagetype */
+	int ret = 1;
+
+	/*
+	 * Ask hypervisor if the pfn is really ram.
+	 * A ballooned page contains no data and reading from such a page
+	 * will cause high load in the hypervisor.
+	 */
+	fn = oldmem_pfn_is_ram;
+	if (fn)
+		ret = fn(pfn);
+
+	return ret;
+}
 
 /* Reads a page from the oldmem device from given offset. */
 static ssize_t read_from_oldmem(char *buf, size_t count,
@@ -55,9 +104,15 @@ static ssize_t read_from_oldmem(char *buf, size_t count,
 		else
 			nr_bytes = count;
 
-		tmp = copy_oldmem_page(pfn, buf, nr_bytes, offset, userbuf);
-		if (tmp < 0)
-			return tmp;
+		/* If pfn is not ram, return zeros for sparse dump files */
+		if (pfn_is_ram(pfn) == 0)
+			memset(buf, 0, nr_bytes);
+		else {
+			tmp = copy_oldmem_page(pfn, buf, nr_bytes,
+						offset, userbuf);
+			if (tmp < 0)
+				return tmp;
+		}
 		*ppos += nr_bytes;
 		count -= nr_bytes;
 		buf += nr_bytes;
@@ -69,37 +124,70 @@ static ssize_t read_from_oldmem(char *buf, size_t 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)
+/*
+ * Architectures may override this function to allocate ELF header in 2nd kernel
+ */
+int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
 {
-	struct vmcore *m;
-	u64 paddr;
+	return 0;
+}
 
-	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;
-		}
+/*
+ * Architectures may override this function to free header
+ */
+void __weak elfcorehdr_free(unsigned long long addr)
+{}
+
+/*
+ * Architectures may override this function to read from ELF header
+ */
+ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos)
+{
+	return read_from_oldmem(buf, count, ppos, 0);
+}
+
+/*
+ * Architectures may override this function to read from notes sections
+ */
+ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
+{
+	return read_from_oldmem(buf, count, ppos, 0);
+}
+
+/*
+ * Architectures may override this function to map oldmem
+ */
+int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma,
+				  unsigned long from, unsigned long pfn,
+				  unsigned long size, pgprot_t prot)
+{
+	return remap_pfn_range(vma, from, pfn, size, prot);
+}
+
+/*
+ * Copy to either kernel or user space
+ */
+static int copy_to(void *target, void *src, size_t size, int userbuf)
+{
+	if (userbuf) {
+		if (copy_to_user((char __user *) target, src, size))
+			return -EFAULT;
+	} else {
+		memcpy(target, src, size);
 	}
-	*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)
+static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos,
+			     int userbuf)
 {
 	ssize_t acc = 0, tmp;
 	size_t tsz;
-	u64 start, nr_bytes;
-	struct vmcore *curr_m = NULL;
+	u64 start;
+	struct vmcore *m = NULL;
 
 	if (buflen == 0 || *fpos >= vmcore_size)
 		return 0;
@@ -110,10 +198,8 @@ static ssize_t read_vmcore(struct file *file, char __user *buffer,
 
 	/* 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))
+		tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen);
+		if (copy_to(buffer, elfcorebuf + *fpos, tsz, userbuf))
 			return -EFAULT;
 		buflen -= tsz;
 		*fpos += tsz;
@@ -125,147 +211,395 @@ static ssize_t read_vmcore(struct file *file, char __user *buffer,
 			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;
+	/* Read Elf note segment */
+	if (*fpos < elfcorebuf_sz + elfnotes_sz) {
+		void *kaddr;
+
+		tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen);
+		kaddr = elfnotes_buf + *fpos - elfcorebuf_sz;
+		if (copy_to(buffer, kaddr, tsz, userbuf))
+			return -EFAULT;
 		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;
+
+		/* leave now if filled buffer already */
+		if (buflen == 0)
+			return acc;
+	}
+
+	list_for_each_entry(m, &vmcore_list, list) {
+		if (*fpos < m->offset + m->size) {
+			tsz = min_t(size_t, m->offset + m->size - *fpos, buflen);
+			start = m->paddr + *fpos - m->offset;
+			tmp = read_from_oldmem(buffer, tsz, &start, userbuf);
+			if (tmp < 0)
+				return tmp;
+			buflen -= tsz;
+			*fpos += tsz;
+			buffer += tsz;
+			acc += tsz;
+
+			/* leave now if filled buffer already */
+			if (buflen == 0)
+				return acc;
 		}
-		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 const struct file_operations proc_vmcore_operations = {
-	.read		= read_vmcore,
-	.llseek		= default_llseek,
+static ssize_t read_vmcore(struct file *file, char __user *buffer,
+			   size_t buflen, loff_t *fpos)
+{
+	return __read_vmcore((__force char *) buffer, buflen, fpos, 1);
+}
+
+/*
+ * The vmcore fault handler uses the page cache and fills data using the
+ * standard __vmcore_read() function.
+ *
+ * On s390 the fault handler is used for memory regions that can't be mapped
+ * directly with remap_pfn_range().
+ */
+static int mmap_vmcore_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+#ifdef CONFIG_S390
+	struct address_space *mapping = vma->vm_file->f_mapping;
+	pgoff_t index = vmf->pgoff;
+	struct page *page;
+	loff_t offset;
+	char *buf;
+	int rc;
+
+	page = find_or_create_page(mapping, index, GFP_KERNEL);
+	if (!page)
+		return VM_FAULT_OOM;
+	if (!PageUptodate(page)) {
+		offset = (loff_t) index << PAGE_CACHE_SHIFT;
+		buf = __va((page_to_pfn(page) << PAGE_SHIFT));
+		rc = __read_vmcore(buf, PAGE_SIZE, &offset, 0);
+		if (rc < 0) {
+			unlock_page(page);
+			page_cache_release(page);
+			return (rc == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
+		}
+		SetPageUptodate(page);
+	}
+	unlock_page(page);
+	vmf->page = page;
+	return 0;
+#else
+	return VM_FAULT_SIGBUS;
+#endif
+}
+
+static const struct vm_operations_struct vmcore_mmap_ops = {
+	.fault = mmap_vmcore_fault,
 };
 
-static struct vmcore* __init get_new_element(void)
+/**
+ * alloc_elfnotes_buf - allocate buffer for ELF note segment in
+ *                      vmalloc memory
+ *
+ * @notes_sz: size of buffer
+ *
+ * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap
+ * the buffer to user-space by means of remap_vmalloc_range().
+ *
+ * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is
+ * disabled and there's no need to allow users to mmap the buffer.
+ */
+static inline char *alloc_elfnotes_buf(size_t notes_sz)
 {
-	return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
+#ifdef CONFIG_MMU
+	return vmalloc_user(notes_sz);
+#else
+	return vzalloc(notes_sz);
+#endif
 }
 
-static u64 __init get_vmcore_size_elf64(char *elfptr)
+/*
+ * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is
+ * essential for mmap_vmcore() in order to map physically
+ * non-contiguous objects (ELF header, ELF note segment and memory
+ * regions in the 1st kernel pointed to by PT_LOAD entries) into
+ * virtually contiguous user-space in ELF layout.
+ */
+#ifdef CONFIG_MMU
+static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
 {
-	int i;
-	u64 size;
-	Elf64_Ehdr *ehdr_ptr;
-	Elf64_Phdr *phdr_ptr;
+	size_t size = vma->vm_end - vma->vm_start;
+	u64 start, end, len, tsz;
+	struct vmcore *m;
 
-	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++;
+	start = (u64)vma->vm_pgoff << PAGE_SHIFT;
+	end = start + size;
+
+	if (size > vmcore_size || end > vmcore_size)
+		return -EINVAL;
+
+	if (vma->vm_flags & (VM_WRITE | VM_EXEC))
+		return -EPERM;
+
+	vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC);
+	vma->vm_flags |= VM_MIXEDMAP;
+	vma->vm_ops = &vmcore_mmap_ops;
+
+	len = 0;
+
+	if (start < elfcorebuf_sz) {
+		u64 pfn;
+
+		tsz = min(elfcorebuf_sz - (size_t)start, size);
+		pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT;
+		if (remap_pfn_range(vma, vma->vm_start, pfn, tsz,
+				    vma->vm_page_prot))
+			return -EAGAIN;
+		size -= tsz;
+		start += tsz;
+		len += tsz;
+
+		if (size == 0)
+			return 0;
 	}
-	return size;
+
+	if (start < elfcorebuf_sz + elfnotes_sz) {
+		void *kaddr;
+
+		tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size);
+		kaddr = elfnotes_buf + start - elfcorebuf_sz;
+		if (remap_vmalloc_range_partial(vma, vma->vm_start + len,
+						kaddr, tsz))
+			goto fail;
+		size -= tsz;
+		start += tsz;
+		len += tsz;
+
+		if (size == 0)
+			return 0;
+	}
+
+	list_for_each_entry(m, &vmcore_list, list) {
+		if (start < m->offset + m->size) {
+			u64 paddr = 0;
+
+			tsz = min_t(size_t, m->offset + m->size - start, size);
+			paddr = m->paddr + start - m->offset;
+			if (remap_oldmem_pfn_range(vma, vma->vm_start + len,
+						   paddr >> PAGE_SHIFT, tsz,
+						   vma->vm_page_prot))
+				goto fail;
+			size -= tsz;
+			start += tsz;
+			len += tsz;
+
+			if (size == 0)
+				return 0;
+		}
+	}
+
+	return 0;
+fail:
+	do_munmap(vma->vm_mm, vma->vm_start, len);
+	return -EAGAIN;
+}
+#else
+static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
+{
+	return -ENOSYS;
 }
+#endif
+
+static const struct file_operations proc_vmcore_operations = {
+	.read		= read_vmcore,
+	.llseek		= default_llseek,
+	.mmap		= mmap_vmcore,
+};
 
-static u64 __init get_vmcore_size_elf32(char *elfptr)
+static struct vmcore* __init get_new_element(void)
+{
+	return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
+}
+
+static u64 __init get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
+				  struct list_head *vc_list)
 {
-	int i;
 	u64 size;
-	Elf32_Ehdr *ehdr_ptr;
-	Elf32_Phdr *phdr_ptr;
+	struct vmcore *m;
 
-	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++;
+	size = elfsz + elfnotesegsz;
+	list_for_each_entry(m, vc_list, list) {
+		size += m->size;
 	}
 	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)
+/**
+ * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry
+ *
+ * @ehdr_ptr: ELF header
+ *
+ * This function updates p_memsz member of each PT_NOTE entry in the
+ * program header table pointed to by @ehdr_ptr to real size of ELF
+ * note segment.
+ */
+static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr)
 {
-	int i, nr_ptnote=0, rc=0;
-	char *tmp;
-	Elf64_Ehdr *ehdr_ptr;
-	Elf64_Phdr phdr, *phdr_ptr;
+	int i, rc=0;
+	Elf64_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));
+	phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
 	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);
+		rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
 		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;
+		while (nhdr_ptr->n_namesz != 0) {
 			sz = sizeof(Elf64_Nhdr) +
 				((nhdr_ptr->n_namesz + 3) & ~3) +
 				((nhdr_ptr->n_descsz + 3) & ~3);
+			if ((real_sz + sz) > max_sz) {
+				pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
+					nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
+				break;
+			}
 			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);
+		phdr_ptr->p_memsz = real_sz;
+		if (real_sz == 0) {
+			pr_warn("Warning: Zero PT_NOTE entries found\n");
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * get_note_number_and_size_elf64 - get the number of PT_NOTE program
+ * headers and sum of real size of their ELF note segment headers and
+ * data.
+ *
+ * @ehdr_ptr: ELF header
+ * @nr_ptnote: buffer for the number of PT_NOTE program headers
+ * @sz_ptnote: buffer for size of unique PT_NOTE program header
+ *
+ * This function is used to merge multiple PT_NOTE program headers
+ * into a unique single one. The resulting unique entry will have
+ * @sz_ptnote in its phdr->p_mem.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf64
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr,
+						 int *nr_ptnote, u64 *sz_ptnote)
+{
+	int i;
+	Elf64_Phdr *phdr_ptr;
+
+	*nr_ptnote = *sz_ptnote = 0;
+
+	phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
+	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+		if (phdr_ptr->p_type != PT_NOTE)
+			continue;
+		*nr_ptnote += 1;
+		*sz_ptnote += phdr_ptr->p_memsz;
+	}
+
+	return 0;
+}
+
+/**
+ * copy_notes_elf64 - copy ELF note segments in a given buffer
+ *
+ * @ehdr_ptr: ELF header
+ * @notes_buf: buffer into which ELF note segments are copied
+ *
+ * This function is used to copy ELF note segment in the 1st kernel
+ * into the buffer @notes_buf in the 2nd kernel. It is assumed that
+ * size of the buffer @notes_buf is equal to or larger than sum of the
+ * real ELF note segment headers and data.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf64
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf)
+{
+	int i, rc=0;
+	Elf64_Phdr *phdr_ptr;
+
+	phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1);
+
+	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+		u64 offset;
+		if (phdr_ptr->p_type != PT_NOTE)
+			continue;
+		offset = phdr_ptr->p_offset;
+		rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
+					   &offset);
+		if (rc < 0)
+			return rc;
+		notes_buf += phdr_ptr->p_memsz;
 	}
 
+	return 0;
+}
+
+/* Merges all the PT_NOTE headers into one. */
+static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
+					   char **notes_buf, size_t *notes_sz)
+{
+	int i, nr_ptnote=0, rc=0;
+	char *tmp;
+	Elf64_Ehdr *ehdr_ptr;
+	Elf64_Phdr phdr;
+	u64 phdr_sz = 0, note_off;
+
+	ehdr_ptr = (Elf64_Ehdr *)elfptr;
+
+	rc = update_note_header_size_elf64(ehdr_ptr);
+	if (rc < 0)
+		return rc;
+
+	rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz);
+	if (rc < 0)
+		return rc;
+
+	*notes_sz = roundup(phdr_sz, PAGE_SIZE);
+	*notes_buf = alloc_elfnotes_buf(*notes_sz);
+	if (!*notes_buf)
+		return -ENOMEM;
+
+	rc = copy_notes_elf64(ehdr_ptr, *notes_buf);
+	if (rc < 0)
+		return rc;
+
 	/* 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_offset  = roundup(note_off, PAGE_SIZE);
 	phdr.p_vaddr   = phdr.p_paddr = 0;
 	phdr.p_filesz  = phdr.p_memsz = phdr_sz;
 	phdr.p_align   = 0;
@@ -279,6 +613,8 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
 	i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
 	*elfsz = *elfsz - i;
 	memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
+	memset(elfptr + *elfsz, 0, i);
+	*elfsz = roundup(*elfsz, PAGE_SIZE);
 
 	/* Modify e_phnum to reflect merged headers. */
 	ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
@@ -286,67 +622,170 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
 	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)
+/**
+ * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry
+ *
+ * @ehdr_ptr: ELF header
+ *
+ * This function updates p_memsz member of each PT_NOTE entry in the
+ * program header table pointed to by @ehdr_ptr to real size of ELF
+ * note segment.
+ */
+static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr)
 {
-	int i, nr_ptnote=0, rc=0;
-	char *tmp;
-	Elf32_Ehdr *ehdr_ptr;
-	Elf32_Phdr phdr, *phdr_ptr;
+	int i, rc=0;
+	Elf32_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));
+	phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
 	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);
+		rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
 		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;
+		while (nhdr_ptr->n_namesz != 0) {
 			sz = sizeof(Elf32_Nhdr) +
 				((nhdr_ptr->n_namesz + 3) & ~3) +
 				((nhdr_ptr->n_descsz + 3) & ~3);
+			if ((real_sz + sz) > max_sz) {
+				pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
+					nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
+				break;
+			}
 			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);
+		phdr_ptr->p_memsz = real_sz;
+		if (real_sz == 0) {
+			pr_warn("Warning: Zero PT_NOTE entries found\n");
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * get_note_number_and_size_elf32 - get the number of PT_NOTE program
+ * headers and sum of real size of their ELF note segment headers and
+ * data.
+ *
+ * @ehdr_ptr: ELF header
+ * @nr_ptnote: buffer for the number of PT_NOTE program headers
+ * @sz_ptnote: buffer for size of unique PT_NOTE program header
+ *
+ * This function is used to merge multiple PT_NOTE program headers
+ * into a unique single one. The resulting unique entry will have
+ * @sz_ptnote in its phdr->p_mem.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf32
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr,
+						 int *nr_ptnote, u64 *sz_ptnote)
+{
+	int i;
+	Elf32_Phdr *phdr_ptr;
+
+	*nr_ptnote = *sz_ptnote = 0;
+
+	phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
+	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+		if (phdr_ptr->p_type != PT_NOTE)
+			continue;
+		*nr_ptnote += 1;
+		*sz_ptnote += phdr_ptr->p_memsz;
 	}
 
+	return 0;
+}
+
+/**
+ * copy_notes_elf32 - copy ELF note segments in a given buffer
+ *
+ * @ehdr_ptr: ELF header
+ * @notes_buf: buffer into which ELF note segments are copied
+ *
+ * This function is used to copy ELF note segment in the 1st kernel
+ * into the buffer @notes_buf in the 2nd kernel. It is assumed that
+ * size of the buffer @notes_buf is equal to or larger than sum of the
+ * real ELF note segment headers and data.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf32
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf)
+{
+	int i, rc=0;
+	Elf32_Phdr *phdr_ptr;
+
+	phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1);
+
+	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+		u64 offset;
+		if (phdr_ptr->p_type != PT_NOTE)
+			continue;
+		offset = phdr_ptr->p_offset;
+		rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
+					   &offset);
+		if (rc < 0)
+			return rc;
+		notes_buf += phdr_ptr->p_memsz;
+	}
+
+	return 0;
+}
+
+/* Merges all the PT_NOTE headers into one. */
+static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
+					   char **notes_buf, size_t *notes_sz)
+{
+	int i, nr_ptnote=0, rc=0;
+	char *tmp;
+	Elf32_Ehdr *ehdr_ptr;
+	Elf32_Phdr phdr;
+	u64 phdr_sz = 0, note_off;
+
+	ehdr_ptr = (Elf32_Ehdr *)elfptr;
+
+	rc = update_note_header_size_elf32(ehdr_ptr);
+	if (rc < 0)
+		return rc;
+
+	rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz);
+	if (rc < 0)
+		return rc;
+
+	*notes_sz = roundup(phdr_sz, PAGE_SIZE);
+	*notes_buf = alloc_elfnotes_buf(*notes_sz);
+	if (!*notes_buf)
+		return -ENOMEM;
+
+	rc = copy_notes_elf32(ehdr_ptr, *notes_buf);
+	if (rc < 0)
+		return rc;
+
 	/* 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_offset  = roundup(note_off, PAGE_SIZE);
 	phdr.p_vaddr   = phdr.p_paddr = 0;
 	phdr.p_filesz  = phdr.p_memsz = phdr_sz;
 	phdr.p_align   = 0;
@@ -360,6 +799,8 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
 	i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
 	*elfsz = *elfsz - i;
 	memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
+	memset(elfptr + *elfsz, 0, i);
+	*elfsz = roundup(*elfsz, PAGE_SIZE);
 
 	/* Modify e_phnum to reflect merged headers. */
 	ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
@@ -371,6 +812,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
  * the new offset fields of exported program headers. */
 static int __init process_ptload_program_headers_elf64(char *elfptr,
 						size_t elfsz,
+						size_t elfnotes_sz,
 						struct list_head *vc_list)
 {
 	int i;
@@ -382,32 +824,38 @@ static int __init process_ptload_program_headers_elf64(char *elfptr,
 	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 */
+	/* Skip Elf header, program headers and Elf note segment. */
+	vmcore_off = elfsz + elfnotes_sz;
 
 	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+		u64 paddr, start, end, size;
+
 		if (phdr_ptr->p_type != PT_LOAD)
 			continue;
 
+		paddr = phdr_ptr->p_offset;
+		start = rounddown(paddr, PAGE_SIZE);
+		end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
+		size = end - start;
+
 		/* 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;
+		new->paddr = start;
+		new->size = size;
 		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;
+		phdr_ptr->p_offset = vmcore_off + (paddr - start);
+		vmcore_off = vmcore_off + size;
 	}
 	return 0;
 }
 
 static int __init process_ptload_program_headers_elf32(char *elfptr,
 						size_t elfsz,
+						size_t elfnotes_sz,
 						struct list_head *vc_list)
 {
 	int i;
@@ -419,43 +867,44 @@ static int __init process_ptload_program_headers_elf32(char *elfptr,
 	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 */
+	/* Skip Elf header, program headers and Elf note segment. */
+	vmcore_off = elfsz + elfnotes_sz;
 
 	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+		u64 paddr, start, end, size;
+
 		if (phdr_ptr->p_type != PT_LOAD)
 			continue;
 
+		paddr = phdr_ptr->p_offset;
+		start = rounddown(paddr, PAGE_SIZE);
+		end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
+		size = end - start;
+
 		/* 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;
+		new->paddr = start;
+		new->size = size;
 		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;
+		phdr_ptr->p_offset = vmcore_off + (paddr - start);
+		vmcore_off = vmcore_off + size;
 	}
 	return 0;
 }
 
 /* Sets offset fields of vmcore elements. */
-static void __init set_vmcore_list_offsets_elf64(char *elfptr,
-						struct list_head *vc_list)
+static void __init set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz,
+					   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);
+	/* Skip Elf header, program headers and Elf note segment. */
+	vmcore_off = elfsz + elfnotes_sz;
 
 	list_for_each_entry(m, vc_list, list) {
 		m->offset = vmcore_off;
@@ -463,24 +912,12 @@ static void __init set_vmcore_list_offsets_elf64(char *elfptr,
 	}
 }
 
-/* Sets offset fields of vmcore elements. */
-static void __init set_vmcore_list_offsets_elf32(char *elfptr,
-						struct list_head *vc_list)
+static void free_elfcorebuf(void)
 {
-	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;
-	}
+	free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig));
+	elfcorebuf = NULL;
+	vfree(elfnotes_buf);
+	elfnotes_buf = NULL;
 }
 
 static int __init parse_crash_elf64_headers(void)
@@ -492,51 +929,51 @@ static int __init parse_crash_elf64_headers(void)
 	addr = elfcorehdr_addr;
 
 	/* Read Elf header */
-	rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0);
+	rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr);
 	if (rc < 0)
 		return rc;
 
 	/* Do some basic Verification. */
 	if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
 		(ehdr.e_type != ET_CORE) ||
-		!vmcore_elf_check_arch(&ehdr) ||
+		!vmcore_elf64_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");
+		pr_warn("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);
+	elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) +
+				ehdr.e_phnum * sizeof(Elf64_Phdr);
+	elfcorebuf_sz = elfcorebuf_sz_orig;
+	elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+					      get_order(elfcorebuf_sz_orig));
 	if (!elfcorebuf)
 		return -ENOMEM;
 	addr = elfcorehdr_addr;
-	rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
-	if (rc < 0) {
-		kfree(elfcorebuf);
-		return rc;
-	}
+	rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
+	if (rc < 0)
+		goto fail;
 
 	/* Merge all PT_NOTE headers into one. */
-	rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
-	if (rc) {
-		kfree(elfcorebuf);
-		return rc;
-	}
+	rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz,
+				      &elfnotes_buf, &elfnotes_sz);
+	if (rc)
+		goto fail;
 	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);
+						  elfnotes_sz, &vmcore_list);
+	if (rc)
+		goto fail;
+	set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
 	return 0;
+fail:
+	free_elfcorebuf();
+	return rc;
 }
 
 static int __init parse_crash_elf32_headers(void)
@@ -548,7 +985,7 @@ static int __init parse_crash_elf32_headers(void)
 	addr = elfcorehdr_addr;
 
 	/* Read Elf header */
-	rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
+	rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr);
 	if (rc < 0)
 		return rc;
 
@@ -562,37 +999,36 @@ static int __init parse_crash_elf32_headers(void)
 		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");
+		pr_warn("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);
+	elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
+	elfcorebuf_sz = elfcorebuf_sz_orig;
+	elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+					      get_order(elfcorebuf_sz_orig));
 	if (!elfcorebuf)
 		return -ENOMEM;
 	addr = elfcorehdr_addr;
-	rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
-	if (rc < 0) {
-		kfree(elfcorebuf);
-		return rc;
-	}
+	rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
+	if (rc < 0)
+		goto fail;
 
 	/* Merge all PT_NOTE headers into one. */
-	rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
-	if (rc) {
-		kfree(elfcorebuf);
-		return rc;
-	}
+	rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz,
+				      &elfnotes_buf, &elfnotes_sz);
+	if (rc)
+		goto fail;
 	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);
+						  elfnotes_sz, &vmcore_list);
+	if (rc)
+		goto fail;
+	set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
 	return 0;
+fail:
+	free_elfcorebuf();
+	return rc;
 }
 
 static int __init parse_crash_elf_headers(void)
@@ -602,12 +1038,11 @@ static int __init parse_crash_elf_headers(void)
 	int rc=0;
 
 	addr = elfcorehdr_addr;
-	rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0);
+	rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr);
 	if (rc < 0)
 		return rc;
 	if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
-		printk(KERN_WARNING "Warning: Core image elf header"
-					" not found\n");
+		pr_warn("Warning: Core image elf header not found\n");
 		return -EINVAL;
 	}
 
@@ -615,21 +1050,19 @@ static int __init parse_crash_elf_headers(void)
 		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");
+		pr_warn("Warning: Core image elf header is not sane\n");
 		return -EINVAL;
 	}
+
+	/* Determine vmcore size. */
+	vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
+				      &vmcore_list);
+
 	return 0;
 }
 
@@ -638,18 +1071,48 @@ static int __init vmcore_init(void)
 {
 	int rc = 0;
 
-	/* If elfcorehdr= has been passed in cmdline, then capture the dump.*/
+	/* Allow architectures to allocate ELF header in 2nd kernel */
+	rc = elfcorehdr_alloc(&elfcorehdr_addr, &elfcorehdr_size);
+	if (rc)
+		return rc;
+	/*
+	 * If elfcorehdr= has been passed in cmdline or created in 2nd kernel,
+	 * then capture the dump.
+	 */
 	if (!(is_vmcore_usable()))
 		return rc;
 	rc = parse_crash_elf_headers();
 	if (rc) {
-		printk(KERN_WARNING "Kdump: vmcore not initialized\n");
+		pr_warn("Kdump: vmcore not initialized\n");
 		return rc;
 	}
+	elfcorehdr_free(elfcorehdr_addr);
+	elfcorehdr_addr = ELFCORE_ADDR_ERR;
 
 	proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
 	if (proc_vmcore)
 		proc_vmcore->size = vmcore_size;
 	return 0;
 }
-module_init(vmcore_init)
+fs_initcall(vmcore_init);
+
+/* Cleanup function for vmcore module. */
+void vmcore_cleanup(void)
+{
+	struct list_head *pos, *next;
+
+	if (proc_vmcore) {
+		proc_remove(proc_vmcore);
+		proc_vmcore = NULL;
+	}
+
+	/* clear the vmcore list. */
+	list_for_each_safe(pos, next, &vmcore_list) {
+		struct vmcore *m;
+
+		m = list_entry(pos, struct vmcore, list);
+		list_del(&m->list);
+		kfree(m);
+	}
+	free_elfcorebuf();
+}