kernel/crash_dump.c

   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  * stores the physical address of elf header of crash image
  10  *
  11  * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
  12  * is_kdump_kernel() to determine if we are booting after a panic. Hence put
  13  * it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
  14  */
  15 unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
  16 EXPORT_SYMBOL_GPL(elfcorehdr_addr);
  17
  18 /*
  19  * stores the size of elf header of crash image
  20  */
  21 unsigned long long elfcorehdr_size;
  22
  23 /*
  24  * elfcorehdr= specifies the location of elf core header stored by the crashed
  25  * kernel. This option will be passed by kexec loader to the capture kernel.
  26  *
  27  * Syntax: elfcorehdr=[size[KMG]@]offset[KMG]
  28  */
  29 static int __init setup_elfcorehdr(char *arg)
  30 {
  31         char *end;
  32         if (!arg)
  33                 return -EINVAL;
  34         elfcorehdr_addr = memparse(arg, &end);
  35         if (*end == '@') {
  36                 elfcorehdr_size = elfcorehdr_addr;
  37                 elfcorehdr_addr = memparse(end + 1, &end);
  38         }
  39         return end > arg ? 0 : -EINVAL;
  40 }
  41 early_param("elfcorehdr", setup_elfcorehdr);