the-tree/kernel/crash_dump.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 #include <linux/kernel.h>
0003 #include <linux/crash_dump.h>
0004 #include <linux/init.h>
0005 #include <linux/errno.h>
0006 #include <linux/export.h>
0007
0008 /*
0009  * stores the physical address of elf header of crash image
0010  *
0011  * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
0012  * is_kdump_kernel() to determine if we are booting after a panic. Hence put
0013  * it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
0014  */
0015 unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
0016 EXPORT_SYMBOL_GPL(elfcorehdr_addr);
0017
0018 /*
0019  * stores the size of elf header of crash image
0020  */
0021 unsigned long long elfcorehdr_size;
0022
0023 /*
0024  * elfcorehdr= specifies the location of elf core header stored by the crashed
0025  * kernel. This option will be passed by kexec loader to the capture kernel.
0026  *
0027  * Syntax: elfcorehdr=[size[KMG]@]offset[KMG]
0028  */
0029 static int __init setup_elfcorehdr(char *arg)
0030 {
0031     char *end;
0032     if (!arg)
0033         return -EINVAL;
0034     elfcorehdr_addr = memparse(arg, &end);
0035     if (*end == '@') {
0036         elfcorehdr_size = elfcorehdr_addr;
0037         elfcorehdr_addr = memparse(end + 1, &end);
0038     }
0039     return end > arg ? 0 : -EINVAL;
0040 }
0041 early_param("elfcorehdr", setup_elfcorehdr);