![Olaf Hering](/assets/img/avatar_default.png)
The balloon driver in a Xen guest frees guest pages and marks them as mmio. When the kernel crashes and the crash kernel attempts to read the oldmem via /proc/vmcore a read from ballooned pages will generate 100% load in dom0 because Xen asks qemu-dm for the page content. Since the reads come in as 8byte requests each ballooned page is tried 512 times. With this change a hook can be registered which checks wether the given pfn is really ram. The hook has to return a value > 0 for ram pages, a value < 0 on error (because the hypercall is not known) and 0 for non-ram pages. This will reduce the time to read /proc/vmcore. Without this change a 512M guest with 128M crashkernel region needs 200 seconds to read it, with this change it takes just 2 seconds. Signed-off-by: Olaf Hering <olaf@aepfle.de> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
702 lines
17 KiB
C
702 lines
17 KiB
C
/*
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* fs/proc/vmcore.c Interface for accessing the crash
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* dump from the system's previous life.
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* Heavily borrowed from fs/proc/kcore.c
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* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
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* Copyright (C) IBM Corporation, 2004. All rights reserved
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*
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*/
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#include <linux/mm.h>
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#include <linux/proc_fs.h>
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#include <linux/user.h>
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#include <linux/elf.h>
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#include <linux/elfcore.h>
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#include <linux/slab.h>
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#include <linux/highmem.h>
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#include <linux/bootmem.h>
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#include <linux/init.h>
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#include <linux/crash_dump.h>
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#include <linux/list.h>
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#include <asm/uaccess.h>
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#include <asm/io.h>
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/* List representing chunks of contiguous memory areas and their offsets in
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* vmcore file.
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*/
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static LIST_HEAD(vmcore_list);
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/* Stores the pointer to the buffer containing kernel elf core headers. */
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static char *elfcorebuf;
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static size_t elfcorebuf_sz;
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/* Total size of vmcore file. */
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static u64 vmcore_size;
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static struct proc_dir_entry *proc_vmcore = NULL;
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/*
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* Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
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* The called function has to take care of module refcounting.
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*/
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static int (*oldmem_pfn_is_ram)(unsigned long pfn);
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int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn))
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{
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if (oldmem_pfn_is_ram)
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return -EBUSY;
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oldmem_pfn_is_ram = fn;
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return 0;
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}
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EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram);
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void unregister_oldmem_pfn_is_ram(void)
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{
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oldmem_pfn_is_ram = NULL;
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wmb();
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}
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EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram);
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static int pfn_is_ram(unsigned long pfn)
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{
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int (*fn)(unsigned long pfn);
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/* pfn is ram unless fn() checks pagetype */
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int ret = 1;
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/*
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* Ask hypervisor if the pfn is really ram.
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* A ballooned page contains no data and reading from such a page
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* will cause high load in the hypervisor.
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*/
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fn = oldmem_pfn_is_ram;
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if (fn)
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ret = fn(pfn);
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return ret;
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}
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/* Reads a page from the oldmem device from given offset. */
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static ssize_t read_from_oldmem(char *buf, size_t count,
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u64 *ppos, int userbuf)
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{
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unsigned long pfn, offset;
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size_t nr_bytes;
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ssize_t read = 0, tmp;
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if (!count)
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return 0;
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offset = (unsigned long)(*ppos % PAGE_SIZE);
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pfn = (unsigned long)(*ppos / PAGE_SIZE);
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do {
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if (count > (PAGE_SIZE - offset))
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nr_bytes = PAGE_SIZE - offset;
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else
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nr_bytes = count;
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/* If pfn is not ram, return zeros for sparse dump files */
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if (pfn_is_ram(pfn) == 0)
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memset(buf, 0, nr_bytes);
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else {
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tmp = copy_oldmem_page(pfn, buf, nr_bytes,
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offset, userbuf);
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if (tmp < 0)
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return tmp;
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}
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*ppos += nr_bytes;
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count -= nr_bytes;
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buf += nr_bytes;
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read += nr_bytes;
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++pfn;
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offset = 0;
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} while (count);
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return read;
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}
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/* Maps vmcore file offset to respective physical address in memroy. */
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static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list,
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struct vmcore **m_ptr)
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{
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struct vmcore *m;
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u64 paddr;
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list_for_each_entry(m, vc_list, list) {
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u64 start, end;
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start = m->offset;
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end = m->offset + m->size - 1;
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if (offset >= start && offset <= end) {
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paddr = m->paddr + offset - start;
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*m_ptr = m;
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return paddr;
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}
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}
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*m_ptr = NULL;
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return 0;
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}
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/* Read from the ELF header and then the crash dump. On error, negative value is
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* returned otherwise number of bytes read are returned.
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*/
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static ssize_t read_vmcore(struct file *file, char __user *buffer,
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size_t buflen, loff_t *fpos)
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{
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ssize_t acc = 0, tmp;
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size_t tsz;
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u64 start, nr_bytes;
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struct vmcore *curr_m = NULL;
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if (buflen == 0 || *fpos >= vmcore_size)
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return 0;
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/* trim buflen to not go beyond EOF */
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if (buflen > vmcore_size - *fpos)
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buflen = vmcore_size - *fpos;
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/* Read ELF core header */
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if (*fpos < elfcorebuf_sz) {
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tsz = elfcorebuf_sz - *fpos;
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if (buflen < tsz)
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tsz = buflen;
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if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
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return -EFAULT;
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buflen -= tsz;
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*fpos += tsz;
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buffer += tsz;
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acc += tsz;
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/* leave now if filled buffer already */
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if (buflen == 0)
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return acc;
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}
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start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m);
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if (!curr_m)
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return -EINVAL;
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if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
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tsz = buflen;
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/* Calculate left bytes in current memory segment. */
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nr_bytes = (curr_m->size - (start - curr_m->paddr));
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if (tsz > nr_bytes)
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tsz = nr_bytes;
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while (buflen) {
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tmp = read_from_oldmem(buffer, tsz, &start, 1);
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if (tmp < 0)
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return tmp;
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buflen -= tsz;
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*fpos += tsz;
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buffer += tsz;
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acc += tsz;
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if (start >= (curr_m->paddr + curr_m->size)) {
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if (curr_m->list.next == &vmcore_list)
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return acc; /*EOF*/
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curr_m = list_entry(curr_m->list.next,
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struct vmcore, list);
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start = curr_m->paddr;
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}
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if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
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tsz = buflen;
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/* Calculate left bytes in current memory segment. */
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nr_bytes = (curr_m->size - (start - curr_m->paddr));
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if (tsz > nr_bytes)
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tsz = nr_bytes;
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}
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return acc;
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}
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static const struct file_operations proc_vmcore_operations = {
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.read = read_vmcore,
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.llseek = default_llseek,
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};
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static struct vmcore* __init get_new_element(void)
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{
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return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
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}
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static u64 __init get_vmcore_size_elf64(char *elfptr)
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{
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int i;
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u64 size;
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Elf64_Ehdr *ehdr_ptr;
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Elf64_Phdr *phdr_ptr;
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ehdr_ptr = (Elf64_Ehdr *)elfptr;
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phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
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size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr));
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for (i = 0; i < ehdr_ptr->e_phnum; i++) {
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size += phdr_ptr->p_memsz;
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phdr_ptr++;
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}
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return size;
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}
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static u64 __init get_vmcore_size_elf32(char *elfptr)
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{
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int i;
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u64 size;
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Elf32_Ehdr *ehdr_ptr;
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Elf32_Phdr *phdr_ptr;
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ehdr_ptr = (Elf32_Ehdr *)elfptr;
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phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
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size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
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for (i = 0; i < ehdr_ptr->e_phnum; i++) {
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size += phdr_ptr->p_memsz;
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phdr_ptr++;
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}
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return size;
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}
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/* Merges all the PT_NOTE headers into one. */
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static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
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struct list_head *vc_list)
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{
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int i, nr_ptnote=0, rc=0;
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char *tmp;
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Elf64_Ehdr *ehdr_ptr;
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Elf64_Phdr phdr, *phdr_ptr;
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Elf64_Nhdr *nhdr_ptr;
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u64 phdr_sz = 0, note_off;
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ehdr_ptr = (Elf64_Ehdr *)elfptr;
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phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
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for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
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int j;
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void *notes_section;
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struct vmcore *new;
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u64 offset, max_sz, sz, real_sz = 0;
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if (phdr_ptr->p_type != PT_NOTE)
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continue;
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nr_ptnote++;
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max_sz = phdr_ptr->p_memsz;
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offset = phdr_ptr->p_offset;
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notes_section = kmalloc(max_sz, GFP_KERNEL);
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if (!notes_section)
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return -ENOMEM;
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rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
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if (rc < 0) {
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kfree(notes_section);
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return rc;
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}
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nhdr_ptr = notes_section;
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for (j = 0; j < max_sz; j += sz) {
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if (nhdr_ptr->n_namesz == 0)
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break;
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sz = sizeof(Elf64_Nhdr) +
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((nhdr_ptr->n_namesz + 3) & ~3) +
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((nhdr_ptr->n_descsz + 3) & ~3);
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real_sz += sz;
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nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
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}
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/* Add this contiguous chunk of notes section to vmcore list.*/
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new = get_new_element();
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if (!new) {
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kfree(notes_section);
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return -ENOMEM;
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}
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new->paddr = phdr_ptr->p_offset;
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new->size = real_sz;
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list_add_tail(&new->list, vc_list);
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phdr_sz += real_sz;
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kfree(notes_section);
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}
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/* Prepare merged PT_NOTE program header. */
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phdr.p_type = PT_NOTE;
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phdr.p_flags = 0;
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note_off = sizeof(Elf64_Ehdr) +
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(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
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phdr.p_offset = note_off;
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phdr.p_vaddr = phdr.p_paddr = 0;
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phdr.p_filesz = phdr.p_memsz = phdr_sz;
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phdr.p_align = 0;
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/* Add merged PT_NOTE program header*/
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tmp = elfptr + sizeof(Elf64_Ehdr);
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memcpy(tmp, &phdr, sizeof(phdr));
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tmp += sizeof(phdr);
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/* Remove unwanted PT_NOTE program headers. */
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i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
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*elfsz = *elfsz - i;
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memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
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/* Modify e_phnum to reflect merged headers. */
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ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
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return 0;
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}
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/* Merges all the PT_NOTE headers into one. */
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static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
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struct list_head *vc_list)
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{
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int i, nr_ptnote=0, rc=0;
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char *tmp;
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Elf32_Ehdr *ehdr_ptr;
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Elf32_Phdr phdr, *phdr_ptr;
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Elf32_Nhdr *nhdr_ptr;
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u64 phdr_sz = 0, note_off;
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ehdr_ptr = (Elf32_Ehdr *)elfptr;
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phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
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for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
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int j;
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void *notes_section;
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struct vmcore *new;
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u64 offset, max_sz, sz, real_sz = 0;
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if (phdr_ptr->p_type != PT_NOTE)
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continue;
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nr_ptnote++;
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max_sz = phdr_ptr->p_memsz;
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offset = phdr_ptr->p_offset;
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notes_section = kmalloc(max_sz, GFP_KERNEL);
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if (!notes_section)
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return -ENOMEM;
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rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
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if (rc < 0) {
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kfree(notes_section);
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return rc;
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}
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nhdr_ptr = notes_section;
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for (j = 0; j < max_sz; j += sz) {
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if (nhdr_ptr->n_namesz == 0)
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break;
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sz = sizeof(Elf32_Nhdr) +
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((nhdr_ptr->n_namesz + 3) & ~3) +
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((nhdr_ptr->n_descsz + 3) & ~3);
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real_sz += sz;
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nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
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}
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/* Add this contiguous chunk of notes section to vmcore list.*/
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new = get_new_element();
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if (!new) {
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kfree(notes_section);
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return -ENOMEM;
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}
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new->paddr = phdr_ptr->p_offset;
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new->size = real_sz;
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list_add_tail(&new->list, vc_list);
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phdr_sz += real_sz;
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kfree(notes_section);
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}
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/* Prepare merged PT_NOTE program header. */
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phdr.p_type = PT_NOTE;
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phdr.p_flags = 0;
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note_off = sizeof(Elf32_Ehdr) +
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(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
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phdr.p_offset = note_off;
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phdr.p_vaddr = phdr.p_paddr = 0;
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phdr.p_filesz = phdr.p_memsz = phdr_sz;
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phdr.p_align = 0;
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/* Add merged PT_NOTE program header*/
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tmp = elfptr + sizeof(Elf32_Ehdr);
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memcpy(tmp, &phdr, sizeof(phdr));
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tmp += sizeof(phdr);
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/* Remove unwanted PT_NOTE program headers. */
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i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
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*elfsz = *elfsz - i;
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memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
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/* Modify e_phnum to reflect merged headers. */
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ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
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return 0;
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}
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/* Add memory chunks represented by program headers to vmcore list. Also update
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* the new offset fields of exported program headers. */
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static int __init process_ptload_program_headers_elf64(char *elfptr,
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size_t elfsz,
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struct list_head *vc_list)
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{
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int i;
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Elf64_Ehdr *ehdr_ptr;
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Elf64_Phdr *phdr_ptr;
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loff_t vmcore_off;
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struct vmcore *new;
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ehdr_ptr = (Elf64_Ehdr *)elfptr;
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phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
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/* First program header is PT_NOTE header. */
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vmcore_off = sizeof(Elf64_Ehdr) +
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(ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
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phdr_ptr->p_memsz; /* Note sections */
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for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
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if (phdr_ptr->p_type != PT_LOAD)
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continue;
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/* Add this contiguous chunk of memory to vmcore list.*/
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new = get_new_element();
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if (!new)
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return -ENOMEM;
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new->paddr = phdr_ptr->p_offset;
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new->size = phdr_ptr->p_memsz;
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list_add_tail(&new->list, vc_list);
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/* Update the program header offset. */
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phdr_ptr->p_offset = vmcore_off;
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vmcore_off = vmcore_off + phdr_ptr->p_memsz;
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}
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return 0;
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}
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static int __init process_ptload_program_headers_elf32(char *elfptr,
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size_t elfsz,
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struct list_head *vc_list)
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{
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int i;
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Elf32_Ehdr *ehdr_ptr;
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Elf32_Phdr *phdr_ptr;
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loff_t vmcore_off;
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struct vmcore *new;
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ehdr_ptr = (Elf32_Ehdr *)elfptr;
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phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
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/* First program header is PT_NOTE header. */
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vmcore_off = sizeof(Elf32_Ehdr) +
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(ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
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|
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) ||
|
|
!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");
|
|
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 (!(is_vmcore_usable()))
|
|
return rc;
|
|
rc = parse_crash_elf_headers();
|
|
if (rc) {
|
|
printk(KERN_WARNING "Kdump: vmcore not initialized\n");
|
|
return rc;
|
|
}
|
|
|
|
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)
|