Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff
[linux-2.6.git] / fs / proc / vmcore.c
index 0c057dc..20d4b22 100644 (file)
@@ -4,6 +4,7 @@
  *     Heavily borrowed from fs/proc/kcore.c
  *     Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
  *     Copyright (C) IBM Corporation, 2004. All rights reserved
+ *
  */
 
 #include <linux/config.h>
 #include <linux/a.out.h>
 #include <linux/elf.h>
 #include <linux/elfcore.h>
-#include <linux/vmalloc.h>
-#include <linux/proc_fs.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>
 
-/* This is to re-use the kcore header creation code */
-static struct kcore_list vmcore_mem;
+/* 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;
 
-static int open_vmcore(struct inode * inode, struct file * filp)
+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;
 }
 
-static ssize_t read_vmcore(struct file *,char __user *,size_t, loff_t *);
+/* 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;
 
-#define BACKUP_START CRASH_BACKUP_BASE
-#define BACKUP_END CRASH_BACKUP_BASE + CRASH_BACKUP_SIZE
-#define REG_SIZE sizeof(elf_gregset_t)
+       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;
+}
 
-struct file_operations proc_vmcore_operations = {
+const struct file_operations proc_vmcore_operations = {
        .read           = read_vmcore,
        .open           = open_vmcore,
 };
 
-struct proc_dir_entry *proc_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;
+}
 
-struct memelfnote
+static u64 __init get_vmcore_size_elf64(char *elfptr)
 {
-       const char *name;
-       int type;
-       unsigned int datasz;
-       void *data;
-};
+       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;
+}
 
-static size_t get_vmcore_size(int *nphdr, size_t *elf_buflen)
+/* 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)
 {
-       size_t size;
+       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);
+               }
 
-       /* We need 1 PT_LOAD segment headers
-        * In addition, we need one PT_NOTE header
-        */
-       *nphdr = 2;
-       size = (size_t)(saved_max_pfn << PAGE_SHIFT);
+               /* 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);
+       }
 
-       *elf_buflen =   sizeof(struct elfhdr) +
-                       (*nphdr + 2)*sizeof(struct elf_phdr) +
-                       3 * sizeof(struct memelfnote) +
-                       sizeof(struct elf_prstatus) +
-                       sizeof(struct elf_prpsinfo) +
-                       sizeof(struct task_struct);
-       *elf_buflen = PAGE_ALIGN(*elf_buflen);
-       return size + *elf_buflen;
+       /* 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;
 }
 
-/*
- * Reads a page from the oldmem device from given offset.
- */
-static ssize_t read_from_oldmem(char *buf, size_t count,
-                            loff_t *ppos, int userbuf)
+/* 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)
 {
-       unsigned long pfn;
-       size_t read = 0;
-
-       pfn = (unsigned long)(*ppos / PAGE_SIZE);
+       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);
+               }
 
-       if (pfn > saved_max_pfn) {
-               read = -EINVAL;
-               goto done;
+               /* 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);
        }
 
-       count = (count > PAGE_SIZE) ? PAGE_SIZE : count;
+       /* 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;
 
-       if (copy_oldmem_page(pfn, buf, count, userbuf)) {
-               read = -EFAULT;
-               goto done;
+       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;
+}
 
-       *ppos += count;
-done:
-       return read;
+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;
 }
 
-/*
- * store an ELF crash dump header in the supplied buffer
- * nphdr is the number of elf_phdr to insert
- */
-static void elf_vmcore_store_hdr(char *bufp, int nphdr, int dataoff)
+/* Sets offset fields of vmcore elements. */
+static void __init set_vmcore_list_offsets_elf64(char *elfptr,
+                                               struct list_head *vc_list)
 {
-       struct elf_prstatus prstatus;   /* NT_PRSTATUS */
-       struct memelfnote notes[1];
-       char reg_buf[REG_SIZE];
-       loff_t reg_ppos;
-       char *buf = bufp;
+       loff_t vmcore_off;
+       Elf64_Ehdr *ehdr_ptr;
+       struct vmcore *m;
+
+       ehdr_ptr = (Elf64_Ehdr *)elfptr;
 
-       vmcore_mem.addr = (unsigned long)__va(0);
-       vmcore_mem.size = saved_max_pfn << PAGE_SHIFT;
-       vmcore_mem.next = NULL;
+       /* Skip Elf header and program headers. */
+       vmcore_off = sizeof(Elf64_Ehdr) +
+                       (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr);
 
-       /* Re-use the kcore code */
-       elf_kcore_store_hdr(bufp, nphdr, dataoff, &vmcore_mem);
-       buf += sizeof(struct elfhdr) + 2*sizeof(struct elf_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;
 
-       /* set up the process status */
-       notes[0].name = "CORE";
-       notes[0].type = NT_PRSTATUS;
-       notes[0].datasz = sizeof(struct elf_prstatus);
-       notes[0].data = &prstatus;
+       ehdr_ptr = (Elf32_Ehdr *)elfptr;
 
-       memset(&prstatus, 0, sizeof(struct elf_prstatus));
+       /* Skip Elf header and program headers. */
+       vmcore_off = sizeof(Elf32_Ehdr) +
+                       (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);
 
-       /* 1 - Get the registers from the reserved memory area */
-       reg_ppos = BACKUP_END + CRASH_RELOCATE_SIZE;
-       read_from_oldmem(reg_buf, REG_SIZE, &reg_ppos, 0);
-       elf_core_copy_regs(&prstatus.pr_reg, (struct pt_regs *)reg_buf);
-       buf = storenote(&notes[0], buf);
+       list_for_each_entry(m, vc_list, list) {
+               m->offset = vmcore_off;
+               vmcore_off += m->size;
+       }
 }
 
-/*
- * read from the ELF header and then the crash dump
- */
-static ssize_t read_vmcore(
-struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
+static int __init parse_crash_elf64_headers(void)
 {
-       ssize_t acc = 0;
-       size_t size, tsz;
-       size_t elf_buflen;
-       int nphdr;
-       unsigned long start;
+       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;
+       }
 
-       tsz =  get_vmcore_size(&nphdr, &elf_buflen);
-       proc_vmcore->size = size = tsz + elf_buflen;
-       if (buflen == 0 || *fpos >= size) {
-               goto done;
+       /* 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;
        }
 
-       /* trim buflen to not go beyond EOF */
-       if (buflen > size - *fpos)
-               buflen = size - *fpos;
+       /* 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;
+}
 
-       /* construct an ELF core header if we'll need some of it */
-       if (*fpos < elf_buflen) {
-               char * elf_buf;
+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;
+       }
 
-               tsz = elf_buflen - *fpos;
-               if (buflen < tsz)
-                       tsz = buflen;
-               elf_buf = kmalloc(elf_buflen, GFP_ATOMIC);
-               if (!elf_buf) {
-                       acc = -ENOMEM;
-                       goto done;
-               }
-               memset(elf_buf, 0, elf_buflen);
-               elf_vmcore_store_hdr(elf_buf, nphdr, elf_buflen);
-               if (copy_to_user(buffer, elf_buf + *fpos, tsz)) {
-                       kfree(elf_buf);
-                       acc = -EFAULT;
-                       goto done;
-               }
-               kfree(elf_buf);
-               buflen -= tsz;
-               *fpos += tsz;
-               buffer += tsz;
-               acc += tsz;
+       /* 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;
+       }
 
-               /* leave now if filled buffer already */
-               if (buflen == 0) {
-                       goto done;
-               }
+       /* 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;
+}
 
-       start = *fpos - elf_buflen;
-       if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
-               tsz = buflen;
+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;
+       }
 
-       while (buflen) {
-               unsigned long p;
-               loff_t pdup;
-
-               if ((start < 0) || (start >= size))
-                       if (clear_user(buffer, tsz)) {
-                               acc = -EFAULT;
-                               goto done;
-                       }
-
-               /* tsz contains actual len of dump to be read.
-                * buflen is the total len that was requested.
-                * This may contain part of ELF header. start
-                * is the fpos for the oldmem region
-                * If the file position corresponds to the second
-                * kernel's memory, we just return zeroes
-                */
-               p = start;
-               if ((p >= BACKUP_START) && (p < BACKUP_END)) {
-                       if (clear_user(buffer, tsz)) {
-                               acc = -EFAULT;
-                               goto done;
-                       }
-
-                       goto read_done;
-               } else if (p < CRASH_RELOCATE_SIZE)
-                       p += BACKUP_END;
-
-               pdup = p;
-               if (read_from_oldmem(buffer, tsz, &pdup, 1)) {
-                       acc = -EINVAL;
-                       goto done;
-               }
+       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;
+}
 
-read_done:
-               buflen -= tsz;
-               *fpos += tsz;
-               buffer += tsz;
-               acc += tsz;
-               start += tsz;
-               tsz = (buflen > PAGE_SIZE ? PAGE_SIZE : buflen);
+/* 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;
        }
 
-done:
-       return acc;
+       /* Initialize /proc/vmcore size if proc is already up. */
+       if (proc_vmcore)
+               proc_vmcore->size = vmcore_size;
+       return 0;
 }
+module_init(vmcore_init)