1/*
2 * kernel/configs.c
3 * Echo the kernel .config file used to build the kernel
4 *
5 * Copyright (C) 2002 Khalid Aziz <khalid_aziz@hp.com>
6 * Copyright (C) 2002 Randy Dunlap <rdunlap@xenotime.net>
7 * Copyright (C) 2002 Al Stone <ahs3@fc.hp.com>
8 * Copyright (C) 2002 Hewlett-Packard Company
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or (at
13 * your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
18 * NON INFRINGEMENT. See the GNU General Public License for more
19 * details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 */
25
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/proc_fs.h>
29#include <linux/seq_file.h>
30#include <linux/init.h>
31#include <linux/uaccess.h>
32
33/*
34 * "IKCFG_ST" and "IKCFG_ED" are used to extract the config data from
35 * a binary kernel image or a module. See scripts/extract-ikconfig.
36 */
37asm (
38" .pushsection .rodata, \"a\" \n"
39" .ascii \"IKCFG_ST\" \n"
40" .global kernel_config_data \n"
41"kernel_config_data: \n"
42" .incbin \"kernel/config_data.gz\" \n"
43" .global kernel_config_data_end \n"
44"kernel_config_data_end: \n"
45" .ascii \"IKCFG_ED\" \n"
46" .popsection \n"
47);
48
49#ifdef CONFIG_IKCONFIG_PROC
50
51extern char kernel_config_data;
52extern char kernel_config_data_end;
53
54static ssize_t
55ikconfig_read_current(struct file *file, char __user *buf,
56 size_t len, loff_t * offset)
57{
58 return simple_read_from_buffer(buf, len, offset,
59 &kernel_config_data,
60 &kernel_config_data_end -
61 &kernel_config_data);
62}
63
64static const struct file_operations ikconfig_file_ops = {
65 .owner = THIS_MODULE,
66 .read = ikconfig_read_current,
67 .llseek = default_llseek,
68};
69
70static int __init ikconfig_init(void)
71{
72 struct proc_dir_entry *entry;
73
74 /* create the current config file */
75 entry = proc_create("config.gz", S_IFREG | S_IRUGO, NULL,
76 &ikconfig_file_ops);
77 if (!entry)
78 return -ENOMEM;
79
80 proc_set_size(entry, &kernel_config_data_end - &kernel_config_data);
81
82 return 0;
83}
84
85static void __exit ikconfig_cleanup(void)
86{
87 remove_proc_entry("config.gz", NULL);
88}
89
90module_init(ikconfig_init);
91module_exit(ikconfig_cleanup);
92
93#endif /* CONFIG_IKCONFIG_PROC */
94
95MODULE_LICENSE("GPL");
96MODULE_AUTHOR("Randy Dunlap");
97MODULE_DESCRIPTION("Echo the kernel .config file used to build the kernel");
98