Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Adrian Bunk | f4b09eb | 2006-01-03 13:37:51 +0100 | [diff] [blame] | 6 | * Copyright (C) 2002 Randy Dunlap <rdunlap@xenotime.net> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/config.h> |
| 27 | #include <linux/kernel.h> |
| 28 | #include <linux/module.h> |
| 29 | #include <linux/proc_fs.h> |
| 30 | #include <linux/seq_file.h> |
| 31 | #include <linux/init.h> |
| 32 | #include <asm/uaccess.h> |
| 33 | |
| 34 | /**************************************************/ |
| 35 | /* the actual current config file */ |
| 36 | |
| 37 | /* |
| 38 | * Define kernel_config_data and kernel_config_data_size, which contains the |
| 39 | * wrapped and compressed configuration file. The file is first compressed |
| 40 | * with gzip and then bounded by two eight byte magic numbers to allow |
| 41 | * extraction from a binary kernel image: |
| 42 | * |
| 43 | * IKCFG_ST |
| 44 | * <image> |
| 45 | * IKCFG_ED |
| 46 | */ |
| 47 | #define MAGIC_START "IKCFG_ST" |
| 48 | #define MAGIC_END "IKCFG_ED" |
| 49 | #include "config_data.h" |
| 50 | |
| 51 | |
| 52 | #define MAGIC_SIZE (sizeof(MAGIC_START) - 1) |
| 53 | #define kernel_config_data_size \ |
| 54 | (sizeof(kernel_config_data) - 1 - MAGIC_SIZE * 2) |
| 55 | |
| 56 | #ifdef CONFIG_IKCONFIG_PROC |
| 57 | |
| 58 | /**************************************************/ |
| 59 | /* globals and useful constants */ |
| 60 | |
| 61 | static ssize_t |
| 62 | ikconfig_read_current(struct file *file, char __user *buf, |
| 63 | size_t len, loff_t * offset) |
| 64 | { |
| 65 | loff_t pos = *offset; |
| 66 | ssize_t count; |
| 67 | |
| 68 | if (pos >= kernel_config_data_size) |
| 69 | return 0; |
| 70 | |
| 71 | count = min(len, (size_t)(kernel_config_data_size - pos)); |
| 72 | if (copy_to_user(buf, kernel_config_data + MAGIC_SIZE + pos, count)) |
| 73 | return -EFAULT; |
| 74 | |
| 75 | *offset += count; |
| 76 | return count; |
| 77 | } |
| 78 | |
| 79 | static struct file_operations ikconfig_file_ops = { |
| 80 | .owner = THIS_MODULE, |
| 81 | .read = ikconfig_read_current, |
| 82 | }; |
| 83 | |
| 84 | /***************************************************/ |
| 85 | /* ikconfig_init: start up everything we need to */ |
| 86 | |
| 87 | static int __init ikconfig_init(void) |
| 88 | { |
| 89 | struct proc_dir_entry *entry; |
| 90 | |
| 91 | /* create the current config file */ |
| 92 | entry = create_proc_entry("config.gz", S_IFREG | S_IRUGO, |
| 93 | &proc_root); |
| 94 | if (!entry) |
| 95 | return -ENOMEM; |
| 96 | |
| 97 | entry->proc_fops = &ikconfig_file_ops; |
| 98 | entry->size = kernel_config_data_size; |
| 99 | |
| 100 | return 0; |
| 101 | } |
| 102 | |
| 103 | /***************************************************/ |
| 104 | /* ikconfig_cleanup: clean up our mess */ |
| 105 | |
| 106 | static void __exit ikconfig_cleanup(void) |
| 107 | { |
| 108 | remove_proc_entry("config.gz", &proc_root); |
| 109 | } |
| 110 | |
| 111 | module_init(ikconfig_init); |
| 112 | module_exit(ikconfig_cleanup); |
| 113 | |
| 114 | MODULE_LICENSE("GPL"); |
| 115 | MODULE_AUTHOR("Randy Dunlap"); |
| 116 | MODULE_DESCRIPTION("Echo the kernel .config file used to build the kernel"); |
| 117 | |
| 118 | #endif /* CONFIG_IKCONFIG_PROC */ |