1 // SPDX-License-Identifier: GPL-2.0
3 * /proc/bootconfig - Extra boot configuration
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>
13 static char *saved_boot_config;
15 static int boot_config_proc_show(struct seq_file *m, void *v)
17 if (saved_boot_config)
18 seq_puts(m, saved_boot_config);
22 /* Rest size of buffer */
23 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
25 /* Return the needed total length if @size is 0 */
26 static int __init copy_xbc_key_value_list(char *dst, size_t size)
28 struct xbc_node *leaf, *vnode;
29 char *key, *end = dst + size;
34 key = kzalloc(XBC_KEYLEN_MAX, GFP_KERNEL);
36 xbc_for_each_key_value(leaf, val) {
37 ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX);
40 ret = snprintf(dst, rest(dst, end), "%s = ", key);
44 vnode = xbc_node_get_child(leaf);
46 xbc_array_for_each_value(vnode, val) {
51 ret = snprintf(dst, rest(dst, end), "%c%s%c%s",
52 q, val, q, xbc_node_is_array(vnode) ? ", " : "\n");
58 ret = snprintf(dst, rest(dst, end), "\"\"\n");
67 return ret < 0 ? ret : dst - (end - size);
70 static int __init proc_boot_config_init(void)
74 len = copy_xbc_key_value_list(NULL, 0);
79 saved_boot_config = kzalloc(len + 1, GFP_KERNEL);
80 if (!saved_boot_config)
83 len = copy_xbc_key_value_list(saved_boot_config, len + 1);
85 kfree(saved_boot_config);
90 proc_create_single("bootconfig", 0, NULL, boot_config_proc_show);
94 fs_initcall(proc_boot_config_init);