1 // SPDX-License-Identifier: GPL-2.0
4 * Masami Hiramatsu <mhiramat@kernel.org>
8 #include <linux/bootconfig.h>
10 #include <linux/ctype.h>
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
13 #include <linux/memblock.h>
14 #include <linux/string.h>
16 #ifdef CONFIG_BOOT_CONFIG_EMBED
17 /* embedded_bootconfig_data is defined in bootconfig-data.S */
18 extern __visible const char embedded_bootconfig_data[];
19 extern __visible const char embedded_bootconfig_data_end[];
21 const char * __init xbc_get_embedded_bootconfig(size_t *size)
23 *size = embedded_bootconfig_data_end - embedded_bootconfig_data;
24 return (*size) ? embedded_bootconfig_data : NULL;
28 #else /* !__KERNEL__ */
30 * NOTE: This is only for tools/bootconfig, because tools/bootconfig will
31 * run the parser sanity test.
32 * This does NOT mean lib/bootconfig.c is available in the user space.
33 * However, if you change this file, please make sure the tools/bootconfig
34 * has no issue on building and running.
36 #include <linux/bootconfig.h>
40 * Extra Boot Config (XBC) is given as tree-structured ascii text of
41 * key-value pairs on memory.
42 * xbc_parse() parses the text to build a simple tree. Each tree node is
43 * simply a key word or a value. A key node may have a next key node or/and
44 * a child node (both key and value). A value node may have a next value
48 static struct xbc_node *xbc_nodes __initdata;
49 static int xbc_node_num __initdata;
50 static char *xbc_data __initdata;
51 static size_t xbc_data_size __initdata;
52 static struct xbc_node *last_parent __initdata;
53 static const char *xbc_err_msg __initdata;
54 static int xbc_err_pos __initdata;
55 static int open_brace[XBC_DEPTH_MAX] __initdata;
56 static int brace_index __initdata;
59 static inline void * __init xbc_alloc_mem(size_t size)
61 return memblock_alloc(size, SMP_CACHE_BYTES);
64 static inline void __init xbc_free_mem(void *addr, size_t size)
66 memblock_free(addr, size);
69 #else /* !__KERNEL__ */
71 static inline void *xbc_alloc_mem(size_t size)
76 static inline void xbc_free_mem(void *addr, size_t size)
82 * xbc_get_info() - Get the information of loaded boot config
83 * @node_size: A pointer to store the number of nodes.
84 * @data_size: A pointer to store the size of bootconfig data.
86 * Get the number of used nodes in @node_size if it is not NULL,
87 * and the size of bootconfig data in @data_size if it is not NULL.
88 * Return 0 if the boot config is initialized, or return -ENODEV.
90 int __init xbc_get_info(int *node_size, size_t *data_size)
96 *node_size = xbc_node_num;
98 *data_size = xbc_data_size;
102 static int __init xbc_parse_error(const char *msg, const char *p)
105 xbc_err_pos = (int)(p - xbc_data);
111 * xbc_root_node() - Get the root node of extended boot config
113 * Return the address of root node of extended boot config. If the
114 * extended boot config is not initiized, return NULL.
116 struct xbc_node * __init xbc_root_node(void)
118 if (unlikely(!xbc_data))
125 * xbc_node_index() - Get the index of XBC node
126 * @node: A target node of getting index.
128 * Return the index number of @node in XBC node list.
130 int __init xbc_node_index(struct xbc_node *node)
132 return node - &xbc_nodes[0];
136 * xbc_node_get_parent() - Get the parent XBC node
137 * @node: An XBC node.
139 * Return the parent node of @node. If the node is top node of the tree,
142 struct xbc_node * __init xbc_node_get_parent(struct xbc_node *node)
144 return node->parent == XBC_NODE_MAX ? NULL : &xbc_nodes[node->parent];
148 * xbc_node_get_child() - Get the child XBC node
149 * @node: An XBC node.
151 * Return the first child node of @node. If the node has no child, return
154 struct xbc_node * __init xbc_node_get_child(struct xbc_node *node)
156 return node->child ? &xbc_nodes[node->child] : NULL;
160 * xbc_node_get_next() - Get the next sibling XBC node
161 * @node: An XBC node.
163 * Return the NEXT sibling node of @node. If the node has no next sibling,
164 * return NULL. Note that even if this returns NULL, it doesn't mean @node
165 * has no siblings. (You also has to check whether the parent's child node
168 struct xbc_node * __init xbc_node_get_next(struct xbc_node *node)
170 return node->next ? &xbc_nodes[node->next] : NULL;
174 * xbc_node_get_data() - Get the data of XBC node
175 * @node: An XBC node.
177 * Return the data (which is always a null terminated string) of @node.
178 * If the node has invalid data, warn and return NULL.
180 const char * __init xbc_node_get_data(struct xbc_node *node)
182 int offset = node->data & ~XBC_VALUE;
184 if (WARN_ON(offset >= xbc_data_size))
187 return xbc_data + offset;
191 xbc_node_match_prefix(struct xbc_node *node, const char **prefix)
193 const char *p = xbc_node_get_data(node);
196 if (strncmp(*prefix, p, len))
210 * xbc_node_find_subkey() - Find a subkey node which matches given key
211 * @parent: An XBC node.
212 * @key: A key string.
214 * Search a key node under @parent which matches @key. The @key can contain
215 * several words jointed with '.'. If @parent is NULL, this searches the
216 * node from whole tree. Return NULL if no node is matched.
218 struct xbc_node * __init
219 xbc_node_find_subkey(struct xbc_node *parent, const char *key)
221 struct xbc_node *node;
224 node = xbc_node_get_subkey(parent);
226 node = xbc_root_node();
228 while (node && xbc_node_is_key(node)) {
229 if (!xbc_node_match_prefix(node, &key))
230 node = xbc_node_get_next(node);
231 else if (*key != '\0')
232 node = xbc_node_get_subkey(node);
241 * xbc_node_find_value() - Find a value node which matches given key
242 * @parent: An XBC node.
243 * @key: A key string.
244 * @vnode: A container pointer of found XBC node.
246 * Search a value node under @parent whose (parent) key node matches @key,
247 * store it in *@vnode, and returns the value string.
248 * The @key can contain several words jointed with '.'. If @parent is NULL,
249 * this searches the node from whole tree. Return the value string if a
250 * matched key found, return NULL if no node is matched.
251 * Note that this returns 0-length string and stores NULL in *@vnode if the
252 * key has no value. And also it will return the value of the first entry if
253 * the value is an array.
256 xbc_node_find_value(struct xbc_node *parent, const char *key,
257 struct xbc_node **vnode)
259 struct xbc_node *node = xbc_node_find_subkey(parent, key);
261 if (!node || !xbc_node_is_key(node))
264 node = xbc_node_get_child(node);
265 if (node && !xbc_node_is_value(node))
271 return node ? xbc_node_get_data(node) : "";
275 * xbc_node_compose_key_after() - Compose partial key string of the XBC node
276 * @root: Root XBC node
277 * @node: Target XBC node.
278 * @buf: A buffer to store the key.
279 * @size: The size of the @buf.
281 * Compose the partial key of the @node into @buf, which is starting right
282 * after @root (@root is not included.) If @root is NULL, this returns full
283 * key words of @node.
284 * Returns the total length of the key stored in @buf. Returns -EINVAL
285 * if @node is NULL or @root is not the ancestor of @node or @root is @node,
286 * or returns -ERANGE if the key depth is deeper than max depth.
287 * This is expected to be used with xbc_find_node() to list up all (child)
288 * keys under given key.
290 int __init xbc_node_compose_key_after(struct xbc_node *root,
291 struct xbc_node *node,
292 char *buf, size_t size)
294 uint16_t keys[XBC_DEPTH_MAX];
295 int depth = 0, ret = 0, total = 0;
297 if (!node || node == root)
300 if (xbc_node_is_value(node))
301 node = xbc_node_get_parent(node);
303 while (node && node != root) {
304 keys[depth++] = xbc_node_index(node);
305 if (depth == XBC_DEPTH_MAX)
307 node = xbc_node_get_parent(node);
312 while (--depth >= 0) {
313 node = xbc_nodes + keys[depth];
314 ret = snprintf(buf, size, "%s%s", xbc_node_get_data(node),
331 * xbc_node_find_next_leaf() - Find the next leaf node under given node
332 * @root: An XBC root node
333 * @node: An XBC node which starts from.
335 * Search the next leaf node (which means the terminal key node) of @node
336 * under @root node (including @root node itself).
337 * Return the next node or NULL if next leaf node is not found.
339 struct xbc_node * __init xbc_node_find_next_leaf(struct xbc_node *root,
340 struct xbc_node *node)
342 struct xbc_node *next;
344 if (unlikely(!xbc_data))
347 if (!node) { /* First try */
352 /* Leaf node may have a subkey */
353 next = xbc_node_get_subkey(node);
359 if (node == root) /* @root was a leaf, no child node. */
362 while (!node->next) {
363 node = xbc_node_get_parent(node);
366 /* User passed a node which is not uder parent */
370 node = xbc_node_get_next(node);
374 while (node && !xbc_node_is_leaf(node))
375 node = xbc_node_get_child(node);
381 * xbc_node_find_next_key_value() - Find the next key-value pair nodes
382 * @root: An XBC root node
383 * @leaf: A container pointer of XBC node which starts from.
385 * Search the next leaf node (which means the terminal key node) of *@leaf
386 * under @root node. Returns the value and update *@leaf if next leaf node
387 * is found, or NULL if no next leaf node is found.
388 * Note that this returns 0-length string if the key has no value, or
389 * the value of the first entry if the value is an array.
391 const char * __init xbc_node_find_next_key_value(struct xbc_node *root,
392 struct xbc_node **leaf)
394 /* tip must be passed */
398 *leaf = xbc_node_find_next_leaf(root, *leaf);
402 return xbc_node_get_data(xbc_node_get_child(*leaf));
404 return ""; /* No value key */
407 /* XBC parse and tree build */
409 static int __init xbc_init_node(struct xbc_node *node, char *data, uint32_t flag)
411 unsigned long offset = data - xbc_data;
413 if (WARN_ON(offset >= XBC_DATA_MAX))
416 node->data = (uint16_t)offset | flag;
423 static struct xbc_node * __init xbc_add_node(char *data, uint32_t flag)
425 struct xbc_node *node;
427 if (xbc_node_num == XBC_NODE_MAX)
430 node = &xbc_nodes[xbc_node_num++];
431 if (xbc_init_node(node, data, flag) < 0)
437 static inline __init struct xbc_node *xbc_last_sibling(struct xbc_node *node)
440 node = xbc_node_get_next(node);
445 static inline __init struct xbc_node *xbc_last_child(struct xbc_node *node)
448 node = xbc_node_get_child(node);
453 static struct xbc_node * __init __xbc_add_sibling(char *data, uint32_t flag, bool head)
455 struct xbc_node *sib, *node = xbc_add_node(data, flag);
459 /* Ignore @head in this case */
460 node->parent = XBC_NODE_MAX;
461 sib = xbc_last_sibling(xbc_nodes);
462 sib->next = xbc_node_index(node);
464 node->parent = xbc_node_index(last_parent);
465 if (!last_parent->child || head) {
466 node->next = last_parent->child;
467 last_parent->child = xbc_node_index(node);
469 sib = xbc_node_get_child(last_parent);
470 sib = xbc_last_sibling(sib);
471 sib->next = xbc_node_index(node);
475 xbc_parse_error("Too many nodes", data);
480 static inline struct xbc_node * __init xbc_add_sibling(char *data, uint32_t flag)
482 return __xbc_add_sibling(data, flag, false);
485 static inline struct xbc_node * __init xbc_add_head_sibling(char *data, uint32_t flag)
487 return __xbc_add_sibling(data, flag, true);
490 static inline __init struct xbc_node *xbc_add_child(char *data, uint32_t flag)
492 struct xbc_node *node = xbc_add_sibling(data, flag);
500 static inline __init bool xbc_valid_keyword(char *key)
505 while (isalnum(*key) || *key == '-' || *key == '_')
511 static char *skip_comment(char *p)
515 ret = strchr(p, '\n');
524 static char *skip_spaces_until_newline(char *p)
526 while (isspace(*p) && *p != '\n')
531 static int __init __xbc_open_brace(char *p)
533 /* Push the last key as open brace */
534 open_brace[brace_index++] = xbc_node_index(last_parent);
535 if (brace_index >= XBC_DEPTH_MAX)
536 return xbc_parse_error("Exceed max depth of braces", p);
541 static int __init __xbc_close_brace(char *p)
544 if (!last_parent || brace_index < 0 ||
545 (open_brace[brace_index] != xbc_node_index(last_parent)))
546 return xbc_parse_error("Unexpected closing brace", p);
548 if (brace_index == 0)
551 last_parent = &xbc_nodes[open_brace[brace_index - 1]];
557 * Return delimiter or error, no node added. As same as lib/cmdline.c,
558 * you can use " around spaces, but can't escape " for value.
560 static int __init __xbc_parse_value(char **__v, char **__n)
570 if (*v == '"' || *v == '\'') {
576 if (!isprint(c) && !isspace(c))
577 return xbc_parse_error("Non printable value", p);
583 p = skip_spaces_until_newline(p);
585 if (c && !strchr(",;\n#}", c))
586 return xbc_parse_error("No value delimiter", p);
591 if (strchr(",;\n#}", c)) {
598 return xbc_parse_error("No closing quotes", p);
601 c = '\n'; /* A comment must be treated as a newline */
609 static int __init xbc_parse_array(char **__v)
611 struct xbc_node *node;
615 if (last_parent->child)
616 last_parent = xbc_node_get_child(last_parent);
619 c = __xbc_parse_value(__v, &next);
623 node = xbc_add_child(*__v, XBC_VALUE);
634 struct xbc_node *find_match_node(struct xbc_node *node, char *k)
637 if (!strcmp(xbc_node_get_data(node), k))
639 node = xbc_node_get_next(node);
644 static int __init __xbc_add_key(char *k)
646 struct xbc_node *node, *child;
648 if (!xbc_valid_keyword(k))
649 return xbc_parse_error("Invalid keyword", k);
651 if (unlikely(xbc_node_num == 0))
654 if (!last_parent) /* the first level */
655 node = find_match_node(xbc_nodes, k);
657 child = xbc_node_get_child(last_parent);
658 /* Since the value node is the first child, skip it. */
659 if (child && xbc_node_is_value(child))
660 child = xbc_node_get_next(child);
661 node = find_match_node(child, k);
668 node = xbc_add_child(k, XBC_KEY);
675 static int __init __xbc_parse_keys(char *k)
681 while ((p = strchr(k, '.'))) {
683 ret = __xbc_add_key(k);
689 return __xbc_add_key(k);
692 static int __init xbc_parse_kv(char **k, char *v, int op)
694 struct xbc_node *prev_parent = last_parent;
695 struct xbc_node *child;
699 ret = __xbc_parse_keys(*k);
703 c = __xbc_parse_value(&v, &next);
707 child = xbc_node_get_child(last_parent);
708 if (child && xbc_node_is_value(child)) {
710 return xbc_parse_error("Value is redefined", v);
712 unsigned short nidx = child->next;
714 xbc_init_node(child, v, XBC_VALUE);
715 child->next = nidx; /* keep subkeys */
719 last_parent = xbc_last_child(child);
721 /* The value node should always be the first child */
722 if (!xbc_add_head_sibling(v, XBC_VALUE))
726 if (c == ',') { /* Array */
727 c = xbc_parse_array(&next);
732 last_parent = prev_parent;
735 ret = __xbc_close_brace(next - 1);
745 static int __init xbc_parse_key(char **k, char *n)
747 struct xbc_node *prev_parent = last_parent;
752 ret = __xbc_parse_keys(*k);
755 last_parent = prev_parent;
762 static int __init xbc_open_brace(char **k, char *n)
766 ret = __xbc_parse_keys(*k);
771 return __xbc_open_brace(n - 1);
774 static int __init xbc_close_brace(char **k, char *n)
778 ret = xbc_parse_key(k, n);
781 /* k is updated in xbc_parse_key() */
783 return __xbc_close_brace(n - 1);
786 static int __init xbc_verify_tree(void)
788 int i, depth, len, wlen;
789 struct xbc_node *n, *m;
793 n = &xbc_nodes[open_brace[brace_index]];
794 return xbc_parse_error("Brace is not closed",
795 xbc_node_get_data(n));
799 if (xbc_node_num == 0) {
800 xbc_parse_error("Empty config", xbc_data);
804 for (i = 0; i < xbc_node_num; i++) {
805 if (xbc_nodes[i].next > xbc_node_num) {
806 return xbc_parse_error("No closing brace",
807 xbc_node_get_data(xbc_nodes + i));
811 /* Key tree limitation check */
817 wlen = strlen(xbc_node_get_data(n)) + 1;
819 if (len > XBC_KEYLEN_MAX)
820 return xbc_parse_error("Too long key length",
821 xbc_node_get_data(n));
823 m = xbc_node_get_child(n);
824 if (m && xbc_node_is_key(m)) {
827 if (depth > XBC_DEPTH_MAX)
828 return xbc_parse_error("Too many key words",
829 xbc_node_get_data(n));
833 m = xbc_node_get_next(n);
835 n = xbc_node_get_parent(n);
838 len -= strlen(xbc_node_get_data(n)) + 1;
840 m = xbc_node_get_next(n);
848 /* Need to setup xbc_data and xbc_nodes before call this. */
849 static int __init xbc_parse_tree(void)
857 q = strpbrk(p, "{}=+;:\n#");
861 ret = xbc_parse_error("No delimiter", p);
871 ret = xbc_parse_error(c == '+' ?
872 "Wrong '+' operator" :
873 "Wrong ':' operator",
879 ret = xbc_parse_kv(&p, q, c);
882 ret = xbc_open_brace(&p, q);
889 ret = xbc_parse_key(&p, q);
892 ret = xbc_close_brace(&p, q);
901 * xbc_exit() - Clean up all parsed bootconfig
903 * This clears all data structures of parsed bootconfig on memory.
904 * If you need to reuse xbc_init() with new boot config, you can
907 void __init xbc_exit(void)
909 xbc_free_mem(xbc_data, xbc_data_size);
913 xbc_free_mem(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX);
919 * xbc_init() - Parse given XBC file and build XBC internal tree
920 * @data: The boot config text original data
921 * @size: The size of @data
922 * @emsg: A pointer of const char * to store the error message
923 * @epos: A pointer of int to store the error position
925 * This parses the boot config text in @data. @size must be smaller
927 * Return the number of stored nodes (>0) if succeeded, or -errno
928 * if there is any error.
929 * In error cases, @emsg will be updated with an error message and
930 * @epos will be updated with the error position which is the byte offset
931 * of @buf. If the error is not a parser error, @epos will be -1.
933 int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos)
942 *emsg = "Bootconfig is already initialized";
945 if (size > XBC_DATA_MAX || size == 0) {
947 *emsg = size ? "Config data is too big" :
948 "Config data is empty";
952 xbc_data = xbc_alloc_mem(size + 1);
955 *emsg = "Failed to allocate bootconfig data";
958 memcpy(xbc_data, data, size);
959 xbc_data[size] = '\0';
960 xbc_data_size = size + 1;
962 xbc_nodes = xbc_alloc_mem(sizeof(struct xbc_node) * XBC_NODE_MAX);
965 *emsg = "Failed to allocate bootconfig nodes";
969 memset(xbc_nodes, 0, sizeof(struct xbc_node) * XBC_NODE_MAX);
971 ret = xbc_parse_tree();
973 ret = xbc_verify_tree();