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/* the actual current config file */
35
36/*
37 * Define kernel_config_data and kernel_config_data_size, which contains the
38 * wrapped and compressed configuration file. The file is first compressed
39 * with gzip and then bounded by two eight byte magic numbers to allow
40 * extraction from a binary kernel image:
41 *
42 * IKCFG_ST
43 * <image>
44 * IKCFG_ED
45 */
46#define MAGIC_START "IKCFG_ST"
47#define MAGIC_END "IKCFG_ED"
48#include "config_data.h"
49
50
51#define MAGIC_SIZE (sizeof(MAGIC_START) - 1)
52#define kernel_config_data_size \
53 (sizeof(kernel_config_data) - 1 - MAGIC_SIZE * 2)
54
55#ifdef CONFIG_IKCONFIG_PROC
56
57static ssize_t
58ikconfig_read_current(struct file *file, char __user *buf,
59 size_t len, loff_t * offset)
60{
61 return simple_read_from_buffer(buf, len, offset,
62 kernel_config_data + MAGIC_SIZE,
63 kernel_config_data_size);
64}
65
66static const struct file_operations ikconfig_file_ops = {
67 .owner = THIS_MODULE,
68 .read = ikconfig_read_current,
69 .llseek = default_llseek,
70};
71
72static int __init ikconfig_init(void)
73{
74 struct proc_dir_entry *entry;
75
76 /* create the current config file */
77 entry = proc_create("config.gz", S_IFREG | S_IRUGO, NULL,
78 &ikconfig_file_ops);
79 if (!entry)
80 return -ENOMEM;
81
82 proc_set_size(entry, kernel_config_data_size);
83
84 return 0;
85}
86
87static void __exit ikconfig_cleanup(void)
88{
89 remove_proc_entry("config.gz", NULL);
90}
91
92module_init(ikconfig_init);
93module_exit(ikconfig_cleanup);
94
95#endif /* CONFIG_IKCONFIG_PROC */
96
97MODULE_LICENSE("GPL");
98MODULE_AUTHOR("Randy Dunlap");
99MODULE_DESCRIPTION("Echo the kernel .config file used to build the kernel");
100