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
57 static ssize_t
ikconfig_read_current(struct file * file,char __user * buf,size_t len,loff_t * offset)58 ikconfig_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
66 static const struct file_operations ikconfig_file_ops = {
67 .owner = THIS_MODULE,
68 .read = ikconfig_read_current,
69 .llseek = default_llseek,
70 };
71
ikconfig_init(void)72 static 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
ikconfig_cleanup(void)87 static void __exit ikconfig_cleanup(void)
88 {
89 remove_proc_entry("config.gz", NULL);
90 }
91
92 module_init(ikconfig_init);
93 module_exit(ikconfig_cleanup);
94
95 #endif /* CONFIG_IKCONFIG_PROC */
96
97 MODULE_LICENSE("GPL");
98 MODULE_AUTHOR("Randy Dunlap");
99 MODULE_DESCRIPTION("Echo the kernel .config file used to build the kernel");
100
