LXR linux/kernel/crash

   1// SPDX-License-Identifier: GPL-2.0-only
   2#include <linux/kernel.h>
   3#include <linux/crash_dump.h>
   4#include <linux/init.h>
   5#include <linux/errno.h>
   6#include <linux/export.h>
   7
   8/*
   9 * If we have booted due to a crash, max_pfn will be a very low value. We need
  10 * to know the amount of memory that the previous kernel used.
  11 */
  12unsigned long saved_max_pfn;
  13
  14/*
  15 * stores the physical address of elf header of crash image
  16 *
  17 * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
  18 * is_kdump_kernel() to determine if we are booting after a panic. Hence put
  19 * it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
  20 */
  21unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
  22EXPORT_SYMBOL_GPL(elfcorehdr_addr);
  23
  24/*
  25 * stores the size of elf header of crash image
  26 */
  27unsigned long long elfcorehdr_size;
  28
  29/*
  30 * elfcorehdr= specifies the location of elf core header stored by the crashed
  31 * kernel. This option will be passed by kexec loader to the capture kernel.
  32 *
  33 * Syntax: elfcorehdr=[size[KMG]@]offset[KMG]
  34 */
  35static int __init setup_elfcorehdr(char *arg)
  36{
  37        char *end;
  38        if (!arg)
  39                return -EINVAL;
  40        elfcorehdr_addr = memparse(arg, &end);
  41        if (*end == '@') {
  42                elfcorehdr_size = elfcorehdr_addr;
  43                elfcorehdr_addr = memparse(end + 1, &end);
  44        }
  45        return end > arg ? 0 : -EINVAL;
  46}
  47early_param("elfcorehdr", setup_elfcorehdr);
  48