LXR linux/kernel/crash

   1#include <linux/kernel.h>
   2#include <linux/crash_dump.h>
   3#include <linux/init.h>
   4#include <linux/errno.h>
   5#include <linux/export.h>
   6
   7/*
   8 * If we have booted due to a crash, max_pfn will be a very low value. We need
   9 * to know the amount of memory that the previous kernel used.
  10 */
  11unsigned long saved_max_pfn;
  12
  13/*
  14 * stores the physical address of elf header of crash image
  15 *
  16 * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
  17 * is_kdump_kernel() to determine if we are booting after a panic. Hence put
  18 * it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
  19 */
  20unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
  21
  22/*
  23 * stores the size of elf header of crash image
  24 */
  25unsigned long long elfcorehdr_size;
  26
  27/*
  28 * elfcorehdr= specifies the location of elf core header stored by the crashed
  29 * kernel. This option will be passed by kexec loader to the capture kernel.
  30 *
  31 * Syntax: elfcorehdr=[size[KMG]@]offset[KMG]
  32 */
  33static int __init setup_elfcorehdr(char *arg)
  34{
  35        char *end;
  36        if (!arg)
  37                return -EINVAL;
  38        elfcorehdr_addr = memparse(arg, &end);
  39        if (*end == '@') {
  40                elfcorehdr_size = elfcorehdr_addr;
  41                elfcorehdr_addr = memparse(end + 1, &end);
  42        }
  43        return end > arg ? 0 : -EINVAL;
  44}
  45early_param("elfcorehdr", setup_elfcorehdr);
  46