projects / linux-block.git / blame
| 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; | |
| 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); | |
| bed5b60b LR |
35 | if (!key) |
| 36 | return -ENOMEM; | |
| c1a3c360 MH |
37 | |
| 38 | xbc_for_each_key_value(leaf, val) { | |
| 39 | ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX); | |
| 40 | if (ret < 0) | |
| 41 | break; | |
| 42 | ret = snprintf(dst, rest(dst, end), "%s = ", key); | |
| 43 | if (ret < 0) | |
| 44 | break; | |
| 45 | dst += ret; | |
| 46 | vnode = xbc_node_get_child(leaf); | |
| 4e264ffd | 47 | if (vnode) { |
| c1a3c360 | 48 | xbc_array_for_each_value(vnode, val) { |
| 4e264ffd MH |
49 | if (strchr(val, '"')) |
| 50 | q = '\''; | |
| 51 | else | |
| 52 | q = '"'; | |
| 53 | ret = snprintf(dst, rest(dst, end), "%c%s%c%s", | |
| ca24306d | 54 | q, val, q, xbc_node_is_array(vnode) ? ", " : "\n"); |
| c1a3c360 MH |
55 | if (ret < 0) |
| 56 | goto out; | |
| 57 | dst += ret; | |
| 58 | } | |
| 59 | } else { | |
| 4e264ffd | 60 | ret = snprintf(dst, rest(dst, end), "\"\"\n"); |
| c1a3c360 MH |
61 | if (ret < 0) |
| 62 | break; | |
| 63 | dst += ret; | |
| 64 | } | |
| 65 | } | |
| 66 | out: | |
| 67 | kfree(key); | |
| 68 | ||
| 69 | return ret < 0 ? ret : dst - (end - size); | |
| 70 | } | |
| 71 | ||
| 72 | static int __init proc_boot_config_init(void) | |
| 73 | { | |
| 74 | int len; | |
| 75 | ||
| 76 | len = copy_xbc_key_value_list(NULL, 0); | |
| 77 | if (len < 0) | |
| 78 | return len; | |
| 79 | ||
| 80 | if (len > 0) { | |
| 81 | saved_boot_config = kzalloc(len + 1, GFP_KERNEL); | |
| 82 | if (!saved_boot_config) | |
| 83 | return -ENOMEM; | |
| 84 | ||
| 85 | len = copy_xbc_key_value_list(saved_boot_config, len + 1); | |
| 86 | if (len < 0) { | |
| 87 | kfree(saved_boot_config); | |
| 88 | return len; | |
| 89 | } | |
| 90 | } | |
| 91 | ||
| 92 | proc_create_single("bootconfig", 0, NULL, boot_config_proc_show); | |
| 93 | ||
| 94 | return 0; | |
| 95 | } | |
| 96 | fs_initcall(proc_boot_config_init); |