]>
Commit | Line | Data |
---|---|---|
c1a3c360 MH |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * /proc/bootconfig - Extra boot configuration | |
4 | */ | |
5 | #include <linux/fs.h> | |
6 | #include <linux/init.h> | |
7 | #include <linux/printk.h> | |
8 | #include <linux/proc_fs.h> | |
9 | #include <linux/seq_file.h> | |
10 | #include <linux/bootconfig.h> | |
11 | #include <linux/slab.h> | |
12 | ||
13 | static char *saved_boot_config; | |
14 | ||
15 | static int boot_config_proc_show(struct seq_file *m, void *v) | |
16 | { | |
17 | if (saved_boot_config) | |
18 | seq_puts(m, saved_boot_config); | |
19 | return 0; | |
20 | } | |
21 | ||
22 | /* Rest size of buffer */ | |
23 | #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) | |
24 | ||
25 | /* Return the needed total length if @size is 0 */ | |
26 | static int __init copy_xbc_key_value_list(char *dst, size_t size) | |
27 | { | |
28 | struct xbc_node *leaf, *vnode; | |
29 | const char *val; | |
30 | char *key, *end = dst + size; | |
31 | int ret = 0; | |
32 | ||
33 | key = kzalloc(XBC_KEYLEN_MAX, GFP_KERNEL); | |
34 | ||
35 | xbc_for_each_key_value(leaf, val) { | |
36 | ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX); | |
37 | if (ret < 0) | |
38 | break; | |
39 | ret = snprintf(dst, rest(dst, end), "%s = ", key); | |
40 | if (ret < 0) | |
41 | break; | |
42 | dst += ret; | |
43 | vnode = xbc_node_get_child(leaf); | |
44 | if (vnode && xbc_node_is_array(vnode)) { | |
45 | xbc_array_for_each_value(vnode, val) { | |
46 | ret = snprintf(dst, rest(dst, end), "\"%s\"%s", | |
47 | val, vnode->next ? ", " : "\n"); | |
48 | if (ret < 0) | |
49 | goto out; | |
50 | dst += ret; | |
51 | } | |
52 | } else { | |
53 | ret = snprintf(dst, rest(dst, end), "\"%s\"\n", val); | |
54 | if (ret < 0) | |
55 | break; | |
56 | dst += ret; | |
57 | } | |
58 | } | |
59 | out: | |
60 | kfree(key); | |
61 | ||
62 | return ret < 0 ? ret : dst - (end - size); | |
63 | } | |
64 | ||
65 | static int __init proc_boot_config_init(void) | |
66 | { | |
67 | int len; | |
68 | ||
69 | len = copy_xbc_key_value_list(NULL, 0); | |
70 | if (len < 0) | |
71 | return len; | |
72 | ||
73 | if (len > 0) { | |
74 | saved_boot_config = kzalloc(len + 1, GFP_KERNEL); | |
75 | if (!saved_boot_config) | |
76 | return -ENOMEM; | |
77 | ||
78 | len = copy_xbc_key_value_list(saved_boot_config, len + 1); | |
79 | if (len < 0) { | |
80 | kfree(saved_boot_config); | |
81 | return len; | |
82 | } | |
83 | } | |
84 | ||
85 | proc_create_single("bootconfig", 0, NULL, boot_config_proc_show); | |
86 | ||
87 | return 0; | |
88 | } | |
89 | fs_initcall(proc_boot_config_init); |