Linux Kernel  3.7.1
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crash_dump.c
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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  */
11 unsigned 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  */
20 unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
21 
22 /*
23  * stores the size of elf header of crash image
24  */
25 unsigned 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  */
33 static 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 == '@') {
41  elfcorehdr_addr = memparse(end + 1, &end);
42  }
43  return end > arg ? 0 : -EINVAL;
44 }
45 early_param("elfcorehdr", setup_elfcorehdr);