Commit | Line | Data |
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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; | |
c1a3c360 | 29 | char *key, *end = dst + size; |
4e264ffd MH |
30 | const char *val; |
31 | char q; | |
c1a3c360 MH |
32 | int ret = 0; |
33 | ||
34 | key = kzalloc(XBC_KEYLEN_MAX, GFP_KERNEL); | |
35 | ||
36 | xbc_for_each_key_value(leaf, val) { | |
37 | ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX); | |
38 | if (ret < 0) | |
39 | break; | |
40 | ret = snprintf(dst, rest(dst, end), "%s = ", key); | |
41 | if (ret < 0) | |
42 | break; | |
43 | dst += ret; | |
44 | vnode = xbc_node_get_child(leaf); | |
4e264ffd | 45 | if (vnode) { |
c1a3c360 | 46 | xbc_array_for_each_value(vnode, val) { |
4e264ffd MH |
47 | if (strchr(val, '"')) |
48 | q = '\''; | |
49 | else | |
50 | q = '"'; | |
51 | ret = snprintf(dst, rest(dst, end), "%c%s%c%s", | |
52 | q, val, q, vnode->next ? ", " : "\n"); | |
c1a3c360 MH |
53 | if (ret < 0) |
54 | goto out; | |
55 | dst += ret; | |
56 | } | |
57 | } else { | |
4e264ffd | 58 | ret = snprintf(dst, rest(dst, end), "\"\"\n"); |
c1a3c360 MH |
59 | if (ret < 0) |
60 | break; | |
61 | dst += ret; | |
62 | } | |
63 | } | |
64 | out: | |
65 | kfree(key); | |
66 | ||
67 | return ret < 0 ? ret : dst - (end - size); | |
68 | } | |
69 | ||
70 | static int __init proc_boot_config_init(void) | |
71 | { | |
72 | int len; | |
73 | ||
74 | len = copy_xbc_key_value_list(NULL, 0); | |
75 | if (len < 0) | |
76 | return len; | |
77 | ||
78 | if (len > 0) { | |
79 | saved_boot_config = kzalloc(len + 1, GFP_KERNEL); | |
80 | if (!saved_boot_config) | |
81 | return -ENOMEM; | |
82 | ||
83 | len = copy_xbc_key_value_list(saved_boot_config, len + 1); | |
84 | if (len < 0) { | |
85 | kfree(saved_boot_config); | |
86 | return len; | |
87 | } | |
88 | } | |
89 | ||
90 | proc_create_single("bootconfig", 0, NULL, boot_config_proc_show); | |
91 | ||
92 | return 0; | |
93 | } | |
94 | fs_initcall(proc_boot_config_init); |