1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * kernel/configs.c |
4 | * Echo the kernel .config file used to build the kernel |
5 | * |
6 | * Copyright (C) 2002 Khalid Aziz <khalid_aziz@hp.com> |
7 | * Copyright (C) 2002 Randy Dunlap <rdunlap@xenotime.net> |
8 | * Copyright (C) 2002 Al Stone <ahs3@fc.hp.com> |
9 | * Copyright (C) 2002 Hewlett-Packard Company |
10 | */ |
11 | |
12 | #include <linux/kernel.h> |
13 | #include <linux/module.h> |
14 | #include <linux/proc_fs.h> |
15 | #include <linux/seq_file.h> |
16 | #include <linux/init.h> |
17 | #include <linux/uaccess.h> |
18 | |
19 | /* |
20 | * "IKCFG_ST" and "IKCFG_ED" are used to extract the config data from |
21 | * a binary kernel image or a module. See scripts/extract-ikconfig. |
22 | */ |
23 | asm ( |
24 | " .pushsection .rodata, \"a\" \n" |
25 | " .ascii \"IKCFG_ST\" \n" |
26 | " .global kernel_config_data \n" |
27 | "kernel_config_data: \n" |
28 | " .incbin \"kernel/config_data.gz\" \n" |
29 | " .global kernel_config_data_end \n" |
30 | "kernel_config_data_end: \n" |
31 | " .ascii \"IKCFG_ED\" \n" |
32 | " .popsection \n" |
33 | ); |
34 | |
35 | #ifdef CONFIG_IKCONFIG_PROC |
36 | |
37 | extern char kernel_config_data; |
38 | extern char kernel_config_data_end; |
39 | |
40 | static ssize_t |
41 | ikconfig_read_current(struct file *file, char __user *buf, |
42 | size_t len, loff_t * offset) |
43 | { |
44 | return simple_read_from_buffer(to: buf, count: len, ppos: offset, |
45 | from: &kernel_config_data, |
46 | available: &kernel_config_data_end - |
47 | &kernel_config_data); |
48 | } |
49 | |
50 | static const struct proc_ops config_gz_proc_ops = { |
51 | .proc_read = ikconfig_read_current, |
52 | .proc_lseek = default_llseek, |
53 | }; |
54 | |
55 | static int __init ikconfig_init(void) |
56 | { |
57 | struct proc_dir_entry *entry; |
58 | |
59 | /* create the current config file */ |
60 | entry = proc_create(name: "config.gz" , S_IFREG | S_IRUGO, NULL, |
61 | proc_ops: &config_gz_proc_ops); |
62 | if (!entry) |
63 | return -ENOMEM; |
64 | |
65 | proc_set_size(entry, &kernel_config_data_end - &kernel_config_data); |
66 | |
67 | return 0; |
68 | } |
69 | |
70 | static void __exit ikconfig_cleanup(void) |
71 | { |
72 | remove_proc_entry("config.gz" , NULL); |
73 | } |
74 | |
75 | module_init(ikconfig_init); |
76 | module_exit(ikconfig_cleanup); |
77 | |
78 | #endif /* CONFIG_IKCONFIG_PROC */ |
79 | |
80 | MODULE_LICENSE("GPL" ); |
81 | MODULE_AUTHOR("Randy Dunlap" ); |
82 | MODULE_DESCRIPTION("Echo the kernel .config file used to build the kernel" ); |
83 | |