1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Extra Boot Config
4 * Masami Hiramatsu <mhiramat@kernel.org>
5 */
6
7 /*
8 * NOTE: This is only for tools/bootconfig, because tools/bootconfig will
9 * run the parser sanity test.
10 * This does NOT mean lib/bootconfig.c is available in the user space.
11 * However, if you change this file, please make sure the tools/bootconfig
12 * has no issue on building and running.
13 */
14 #include <linux/bootconfig.h>
15
16 #ifdef __KERNEL__
17 #include <linux/bug.h>
18 #include <linux/ctype.h>
19 #include <linux/errno.h>
20 #include <linux/kernel.h>
21 #include <linux/memblock.h>
22 #include <linux/string.h>
23
24 #ifdef CONFIG_BOOT_CONFIG_EMBED
25 /* embedded_bootconfig_data is defined in bootconfig-data.S */
26 extern __visible const char embedded_bootconfig_data[];
27 extern __visible const char embedded_bootconfig_data_end[];
28
29 const char * __init xbc_get_embedded_bootconfig(size_t *size)
30 {
31 *size = embedded_bootconfig_data_end - embedded_bootconfig_data;
32 return (*size) ? embedded_bootconfig_data : NULL;
33 }
34 #endif
35 #endif
36
37 /*
38 * Extra Boot Config (XBC) is given as tree-structured ascii text of
39 * key-value pairs on memory.
40 * xbc_parse() parses the text to build a simple tree. Each tree node is
41 * simply a key word or a value. A key node may have a next key node or/and
42 * a child node (both key and value). A value node may have a next value
43 * node (for array).
44 */
45
46 static struct xbc_node *xbc_nodes __initdata;
47 static int xbc_node_num __initdata;
48 static char *xbc_data __initdata;
49 static size_t xbc_data_size __initdata;
50 static struct xbc_node *last_parent __initdata;
51 static const char *xbc_err_msg __initdata;
52 static int xbc_err_pos __initdata;
53 static int open_brace[XBC_DEPTH_MAX] __initdata;
54 static int brace_index __initdata;
55
56 #ifdef __KERNEL__
57 static inline void * __init xbc_alloc_mem(size_t size)
58 {
59 return memblock_alloc(size, SMP_CACHE_BYTES);
60 }
61
62 static inline void __init xbc_free_mem(void *addr, size_t size, bool early)
63 {
64 if (early)
65 memblock_free(addr, size);
66 else if (addr)
67 memblock_free_late(__pa(addr), size);
68 }
69
70 #else /* !__KERNEL__ */
71
72 static inline void *xbc_alloc_mem(size_t size)
73 {
74 return malloc(size);
75 }
76
77 static inline void xbc_free_mem(void *addr, size_t size, bool early)
78 {
79 free(addr);
80 }
81 #endif
82 /**
83 * xbc_get_info() - Get the information of loaded boot config
84 * @node_size: A pointer to store the number of nodes.
85 * @data_size: A pointer to store the size of bootconfig data.
86 *
87 * Get the number of used nodes in @node_size if it is not NULL,
88 * and the size of bootconfig data in @data_size if it is not NULL.
89 * Return 0 if the boot config is initialized, or return -ENODEV.
90 */
91 int __init xbc_get_info(int *node_size, size_t *data_size)
92 {
93 if (!xbc_data)
94 return -ENODEV;
95
96 if (node_size)
97 *node_size = xbc_node_num;
98 if (data_size)
99 *data_size = xbc_data_size;
100 return 0;
101 }
102
103 static int __init xbc_parse_error(const char *msg, const char *p)
104 {
105 xbc_err_msg = msg;
106 xbc_err_pos = (int)(p - xbc_data);
107
108 return -EINVAL;
109 }
110
111 /**
112 * xbc_root_node() - Get the root node of extended boot config
113 *
114 * Return the address of root node of extended boot config. If the
115 * extended boot config is not initiized, return NULL.
116 */
117 struct xbc_node * __init xbc_root_node(void)
118 {
119 if (unlikely(!xbc_data))
120 return NULL;
121
122 return xbc_nodes;
123 }
124
125 /**
126 * xbc_node_index() - Get the index of XBC node
127 * @node: A target node of getting index.
128 *
129 * Return the index number of @node in XBC node list.
130 */
131 int __init xbc_node_index(struct xbc_node *node)
132 {
133 return node - &xbc_nodes[0];
134 }
135
136 /**
137 * xbc_node_get_parent() - Get the parent XBC node
138 * @node: An XBC node.
139 *
140 * Return the parent node of @node. If the node is top node of the tree,
141 * return NULL.
142 */
143 struct xbc_node * __init xbc_node_get_parent(struct xbc_node *node)
144 {
145 return node->parent == XBC_NODE_MAX ? NULL : &xbc_nodes[node->parent];
146 }
147
148 /**
149 * xbc_node_get_child() - Get the child XBC node
150 * @node: An XBC node.
151 *
152 * Return the first child node of @node. If the node has no child, return
153 * NULL.
154 */
155 struct xbc_node * __init xbc_node_get_child(struct xbc_node *node)
156 {
157 return node->child ? &xbc_nodes[node->child] : NULL;
158 }
159
160 /**
161 * xbc_node_get_next() - Get the next sibling XBC node
162 * @node: An XBC node.
163 *
164 * Return the NEXT sibling node of @node. If the node has no next sibling,
165 * return NULL. Note that even if this returns NULL, it doesn't mean @node
166 * has no siblings. (You also has to check whether the parent's child node
167 * is @node or not.)
168 */
169 struct xbc_node * __init xbc_node_get_next(struct xbc_node *node)
170 {
171 return node->next ? &xbc_nodes[node->next] : NULL;
172 }
173
174 /**
175 * xbc_node_get_data() - Get the data of XBC node
176 * @node: An XBC node.
177 *
178 * Return the data (which is always a null terminated string) of @node.
179 * If the node has invalid data, warn and return NULL.
180 */
181 const char * __init xbc_node_get_data(struct xbc_node *node)
182 {
183 int offset = node->data & ~XBC_VALUE;
184
185 if (WARN_ON(offset >= xbc_data_size))
186 return NULL;
187
188 return xbc_data + offset;
189 }
190
191 static bool __init
192 xbc_node_match_prefix(struct xbc_node *node, const char **prefix)
193 {
194 const char *p = xbc_node_get_data(node);
195 int len = strlen(p);
196
197 if (strncmp(*prefix, p, len))
198 return false;
199
200 p = *prefix + len;
201 if (*p == '.')
202 p++;
203 else if (*p != '\0')
204 return false;
205 *prefix = p;
206
207 return true;
208 }
209
210 /**
211 * xbc_node_find_subkey() - Find a subkey node which matches given key
212 * @parent: An XBC node.
213 * @key: A key string.
214 *
215 * Search a key node under @parent which matches @key. The @key can contain
216 * several words jointed with '.'. If @parent is NULL, this searches the
217 * node from whole tree. Return NULL if no node is matched.
218 */
219 struct xbc_node * __init
220 xbc_node_find_subkey(struct xbc_node *parent, const char *key)
221 {
222 struct xbc_node *node;
223
224 if (parent)
225 node = xbc_node_get_subkey(parent);
226 else
227 node = xbc_root_node();
228
229 while (node && xbc_node_is_key(node)) {
230 if (!xbc_node_match_prefix(node, &key))
231 node = xbc_node_get_next(node);
232 else if (*key != '\0')
233 node = xbc_node_get_subkey(node);
234 else
235 break;
236 }
237
238 return node;
239 }
240
241 /**
242 * xbc_node_find_value() - Find a value node which matches given key
243 * @parent: An XBC node.
244 * @key: A key string.
245 * @vnode: A container pointer of found XBC node.
246 *
247 * Search a value node under @parent whose (parent) key node matches @key,
248 * store it in *@vnode, and returns the value string.
249 * The @key can contain several words jointed with '.'. If @parent is NULL,
250 * this searches the node from whole tree. Return the value string if a
251 * matched key found, return NULL if no node is matched.
252 * Note that this returns 0-length string and stores NULL in *@vnode if the
253 * key has no value. And also it will return the value of the first entry if
254 * the value is an array.
255 */
256 const char * __init
257 xbc_node_find_value(struct xbc_node *parent, const char *key,
258 struct xbc_node **vnode)
259 {
260 struct xbc_node *node = xbc_node_find_subkey(parent, key);
261
262 if (!node || !xbc_node_is_key(node))
263 return NULL;
264
265 node = xbc_node_get_child(node);
266 if (node && !xbc_node_is_value(node))
267 return NULL;
268
269 if (vnode)
270 *vnode = node;
271
272 return node ? xbc_node_get_data(node) : "";
273 }
274
275 /**
276 * xbc_node_compose_key_after() - Compose partial key string of the XBC node
277 * @root: Root XBC node
278 * @node: Target XBC node.
279 * @buf: A buffer to store the key.
280 * @size: The size of the @buf.
281 *
282 * Compose the partial key of the @node into @buf, which is starting right
283 * after @root (@root is not included.) If @root is NULL, this returns full
284 * key words of @node.
285 * Returns the total length of the key stored in @buf. Returns -EINVAL
286 * if @node is NULL or @root is not the ancestor of @node or @root is @node,
287 * or returns -ERANGE if the key depth is deeper than max depth.
288 * This is expected to be used with xbc_find_node() to list up all (child)
289 * keys under given key.
290 */
291 int __init xbc_node_compose_key_after(struct xbc_node *root,
292 struct xbc_node *node,
293 char *buf, size_t size)
294 {
295 uint16_t keys[XBC_DEPTH_MAX];
296 int depth = 0, ret = 0, total = 0;
297
298 if (!node || node == root)
299 return -EINVAL;
300
301 if (xbc_node_is_value(node))
302 node = xbc_node_get_parent(node);
303
304 while (node && node != root) {
305 keys[depth++] = xbc_node_index(node);
306 if (depth == XBC_DEPTH_MAX)
307 return -ERANGE;
308 node = xbc_node_get_parent(node);
309 }
310 if (!node && root)
311 return -EINVAL;
312
313 while (--depth >= 0) {
314 node = xbc_nodes + keys[depth];
315 ret = snprintf(buf, size, "%s%s", xbc_node_get_data(node),
316 depth ? "." : "");
317 if (ret < 0)
318 return ret;
319 if (ret > size) {
320 size = 0;
321 } else {
322 size -= ret;
323 buf += ret;
324 }
325 total += ret;
326 }
327
328 return total;
329 }
330
331 /**
332 * xbc_node_find_next_leaf() - Find the next leaf node under given node
333 * @root: An XBC root node
334 * @node: An XBC node which starts from.
335 *
336 * Search the next leaf node (which means the terminal key node) of @node
337 * under @root node (including @root node itself).
338 * Return the next node or NULL if next leaf node is not found.
339 */
340 struct xbc_node * __init xbc_node_find_next_leaf(struct xbc_node *root,
341 struct xbc_node *node)
342 {
343 struct xbc_node *next;
344
345 if (unlikely(!xbc_data))
346 return NULL;
347
348 if (!node) { /* First try */
349 node = root;
350 if (!node)
351 node = xbc_nodes;
352 } else {
353 /* Leaf node may have a subkey */
354 next = xbc_node_get_subkey(node);
355 if (next) {
356 node = next;
357 goto found;
358 }
359
360 if (node == root) /* @root was a leaf, no child node. */
361 return NULL;
362
363 while (!node->next) {
364 node = xbc_node_get_parent(node);
365 if (node == root)
366 return NULL;
367 /* User passed a node which is not uder parent */
368 if (WARN_ON(!node))
369 return NULL;
370 }
371 node = xbc_node_get_next(node);
372 }
373
374 found:
375 while (node && !xbc_node_is_leaf(node))
376 node = xbc_node_get_child(node);
377
378 return node;
379 }
380
381 /**
382 * xbc_node_find_next_key_value() - Find the next key-value pair nodes
383 * @root: An XBC root node
384 * @leaf: A container pointer of XBC node which starts from.
385 *
386 * Search the next leaf node (which means the terminal key node) of *@leaf
387 * under @root node. Returns the value and update *@leaf if next leaf node
388 * is found, or NULL if no next leaf node is found.
389 * Note that this returns 0-length string if the key has no value, or
390 * the value of the first entry if the value is an array.
391 */
392 const char * __init xbc_node_find_next_key_value(struct xbc_node *root,
393 struct xbc_node **leaf)
394 {
395 /* tip must be passed */
396 if (WARN_ON(!leaf))
397 return NULL;
398
399 *leaf = xbc_node_find_next_leaf(root, *leaf);
400 if (!*leaf)
401 return NULL;
402 if ((*leaf)->child)
403 return xbc_node_get_data(xbc_node_get_child(*leaf));
404 else
405 return ""; /* No value key */
406 }
407
408 /* XBC parse and tree build */
409
410 static int __init xbc_init_node(struct xbc_node *node, char *data, uint32_t flag)
411 {
412 unsigned long offset = data - xbc_data;
413
414 if (WARN_ON(offset >= XBC_DATA_MAX))
415 return -EINVAL;
416
417 node->data = (uint16_t)offset | flag;
418 node->child = 0;
419 node->next = 0;
420
421 return 0;
422 }
423
424 static struct xbc_node * __init xbc_add_node(char *data, uint32_t flag)
425 {
426 struct xbc_node *node;
427
428 if (xbc_node_num == XBC_NODE_MAX)
429 return NULL;
430
431 node = &xbc_nodes[xbc_node_num++];
432 if (xbc_init_node(node, data, flag) < 0)
433 return NULL;
434
435 return node;
436 }
437
438 static inline __init struct xbc_node *xbc_last_sibling(struct xbc_node *node)
439 {
440 while (node->next)
441 node = xbc_node_get_next(node);
442
443 return node;
444 }
445
446 static inline __init struct xbc_node *xbc_last_child(struct xbc_node *node)
447 {
448 while (node->child)
449 node = xbc_node_get_child(node);
450
451 return node;
452 }
453
454 static struct xbc_node * __init __xbc_add_sibling(char *data, uint32_t flag, bool head)
455 {
456 struct xbc_node *sib, *node = xbc_add_node(data, flag);
457
458 if (node) {
459 if (!last_parent) {
460 /* Ignore @head in this case */
461 node->parent = XBC_NODE_MAX;
462 sib = xbc_last_sibling(xbc_nodes);
463 sib->next = xbc_node_index(node);
464 } else {
465 node->parent = xbc_node_index(last_parent);
466 if (!last_parent->child || head) {
467 node->next = last_parent->child;
468 last_parent->child = xbc_node_index(node);
469 } else {
470 sib = xbc_node_get_child(last_parent);
471 sib = xbc_last_sibling(sib);
472 sib->next = xbc_node_index(node);
473 }
474 }
475 } else
476 xbc_parse_error("Too many nodes", data);
477
478 return node;
479 }
480
481 static inline struct xbc_node * __init xbc_add_sibling(char *data, uint32_t flag)
482 {
483 return __xbc_add_sibling(data, flag, false);
484 }
485
486 static inline struct xbc_node * __init xbc_add_head_sibling(char *data, uint32_t flag)
487 {
488 return __xbc_add_sibling(data, flag, true);
489 }
490
491 static inline __init struct xbc_node *xbc_add_child(char *data, uint32_t flag)
492 {
493 struct xbc_node *node = xbc_add_sibling(data, flag);
494
495 if (node)
496 last_parent = node;
497
498 return node;
499 }
500
501 static inline __init bool xbc_valid_keyword(char *key)
502 {
503 if (key[0] == '\0')
504 return false;
505
506 while (isalnum(*key) || *key == '-' || *key == '_')
507 key++;
508
509 return *key == '\0';
510 }
511
512 static char *skip_comment(char *p)
513 {
514 char *ret;
515
516 ret = strchr(p, '\n');
517 if (!ret)
518 ret = p + strlen(p);
519 else
520 ret++;
521
522 return ret;
523 }
524
525 static char *skip_spaces_until_newline(char *p)
526 {
527 while (isspace(*p) && *p != '\n')
528 p++;
529 return p;
530 }
531
532 static int __init __xbc_open_brace(char *p)
533 {
534 /* Push the last key as open brace */
535 open_brace[brace_index++] = xbc_node_index(last_parent);
536 if (brace_index >= XBC_DEPTH_MAX)
537 return xbc_parse_error("Exceed max depth of braces", p);
538
539 return 0;
540 }
541
542 static int __init __xbc_close_brace(char *p)
543 {
544 brace_index--;
545 if (!last_parent || brace_index < 0 ||
546 (open_brace[brace_index] != xbc_node_index(last_parent)))
547 return xbc_parse_error("Unexpected closing brace", p);
548
549 if (brace_index == 0)
550 last_parent = NULL;
551 else
552 last_parent = &xbc_nodes[open_brace[brace_index - 1]];
553
554 return 0;
555 }
556
557 /*
558 * Return delimiter or error, no node added. As same as lib/cmdline.c,
559 * you can use " around spaces, but can't escape " for value.
560 */
561 static int __init __xbc_parse_value(char **__v, char **__n)
562 {
563 char *p, *v = *__v;
564 int c, quotes = 0;
565
566 v = skip_spaces(v);
567 while (*v == '#') {
568 v = skip_comment(v);
569 v = skip_spaces(v);
570 }
571 if (*v == '"' || *v == '\'') {
572 quotes = *v;
573 v++;
574 }
575 p = v - 1;
576 while ((c = *++p)) {
577 if (!isprint(c) && !isspace(c))
578 return xbc_parse_error("Non printable value", p);
579 if (quotes) {
580 if (c != quotes)
581 continue;
582 quotes = 0;
583 *p++ = '\0';
584 p = skip_spaces_until_newline(p);
585 c = *p;
586 if (c && !strchr(",;\n#}", c))
587 return xbc_parse_error("No value delimiter", p);
588 if (*p)
589 p++;
590 break;
591 }
592 if (strchr(",;\n#}", c)) {
593 *p++ = '\0';
594 v = strim(v);
595 break;
596 }
597 }
598 if (quotes)
599 return xbc_parse_error("No closing quotes", p);
600 if (c == '#') {
601 p = skip_comment(p);
602 c = '\n'; /* A comment must be treated as a newline */
603 }
604 *__n = p;
605 *__v = v;
606
607 return c;
608 }
609
610 static int __init xbc_parse_array(char **__v)
611 {
612 struct xbc_node *node;
613 char *next;
614 int c = 0;
615
616 if (last_parent->child)
617 last_parent = xbc_node_get_child(last_parent);
618
619 do {
620 c = __xbc_parse_value(__v, &next);
621 if (c < 0)
622 return c;
623
624 node = xbc_add_child(*__v, XBC_VALUE);
625 if (!node)
626 return -ENOMEM;
627 *__v = next;
628 } while (c == ',');
629 node->child = 0;
630
631 return c;
632 }
633
634 static inline __init
635 struct xbc_node *find_match_node(struct xbc_node *node, char *k)
636 {
637 while (node) {
638 if (!strcmp(xbc_node_get_data(node), k))
639 break;
640 node = xbc_node_get_next(node);
641 }
642 return node;
643 }
644
645 static int __init __xbc_add_key(char *k)
646 {
647 struct xbc_node *node, *child;
648
649 if (!xbc_valid_keyword(k))
650 return xbc_parse_error("Invalid keyword", k);
651
652 if (unlikely(xbc_node_num == 0))
653 goto add_node;
654
655 if (!last_parent) /* the first level */
656 node = find_match_node(xbc_nodes, k);
657 else {
658 child = xbc_node_get_child(last_parent);
659 /* Since the value node is the first child, skip it. */
660 if (child && xbc_node_is_value(child))
661 child = xbc_node_get_next(child);
662 node = find_match_node(child, k);
663 }
664
665 if (node)
666 last_parent = node;
667 else {
668 add_node:
669 node = xbc_add_child(k, XBC_KEY);
670 if (!node)
671 return -ENOMEM;
672 }
673 return 0;
674 }
675
676 static int __init __xbc_parse_keys(char *k)
677 {
678 char *p;
679 int ret;
680
681 k = strim(k);
682 while ((p = strchr(k, '.'))) {
683 *p++ = '\0';
684 ret = __xbc_add_key(k);
685 if (ret)
686 return ret;
687 k = p;
688 }
689
690 return __xbc_add_key(k);
691 }
692
693 static int __init xbc_parse_kv(char **k, char *v, int op)
694 {
695 struct xbc_node *prev_parent = last_parent;
696 struct xbc_node *child;
697 char *next;
698 int c, ret;
699
700 ret = __xbc_parse_keys(*k);
701 if (ret)
702 return ret;
703
704 c = __xbc_parse_value(&v, &next);
705 if (c < 0)
706 return c;
707
708 child = xbc_node_get_child(last_parent);
709 if (child && xbc_node_is_value(child)) {
710 if (op == '=')
711 return xbc_parse_error("Value is redefined", v);
712 if (op == ':') {
713 unsigned short nidx = child->next;
714
715 xbc_init_node(child, v, XBC_VALUE);
716 child->next = nidx; /* keep subkeys */
717 goto array;
718 }
719 /* op must be '+' */
720 last_parent = xbc_last_child(child);
721 }
722 /* The value node should always be the first child */
723 if (!xbc_add_head_sibling(v, XBC_VALUE))
724 return -ENOMEM;
725
726 array:
727 if (c == ',') { /* Array */
728 c = xbc_parse_array(&next);
729 if (c < 0)
730 return c;
731 }
732
733 last_parent = prev_parent;
734
735 if (c == '}') {
736 ret = __xbc_close_brace(next - 1);
737 if (ret < 0)
738 return ret;
739 }
740
741 *k = next;
742
743 return 0;
744 }
745
746 static int __init xbc_parse_key(char **k, char *n)
747 {
748 struct xbc_node *prev_parent = last_parent;
749 int ret;
750
751 *k = strim(*k);
752 if (**k != '\0') {
753 ret = __xbc_parse_keys(*k);
754 if (ret)
755 return ret;
756 last_parent = prev_parent;
757 }
758 *k = n;
759
760 return 0;
761 }
762
763 static int __init xbc_open_brace(char **k, char *n)
764 {
765 int ret;
766
767 ret = __xbc_parse_keys(*k);
768 if (ret)
769 return ret;
770 *k = n;
771
772 return __xbc_open_brace(n - 1);
773 }
774
775 static int __init xbc_close_brace(char **k, char *n)
776 {
777 int ret;
778
779 ret = xbc_parse_key(k, n);
780 if (ret)
781 return ret;
782 /* k is updated in xbc_parse_key() */
783
784 return __xbc_close_brace(n - 1);
785 }
786
787 static int __init xbc_verify_tree(void)
788 {
789 int i, depth, len, wlen;
790 struct xbc_node *n, *m;
791
792 /* Brace closing */
793 if (brace_index) {
794 n = &xbc_nodes[open_brace[brace_index]];
795 return xbc_parse_error("Brace is not closed",
796 xbc_node_get_data(n));
797 }
798
799 /* Empty tree */
800 if (xbc_node_num == 0) {
801 xbc_parse_error("Empty config", xbc_data);
802 return -ENOENT;
803 }
804
805 for (i = 0; i < xbc_node_num; i++) {
806 if (xbc_nodes[i].next > xbc_node_num) {
807 return xbc_parse_error("No closing brace",
808 xbc_node_get_data(xbc_nodes + i));
809 }
810 }
811
812 /* Key tree limitation check */
813 n = &xbc_nodes[0];
814 depth = 1;
815 len = 0;
816
817 while (n) {
818 wlen = strlen(xbc_node_get_data(n)) + 1;
819 len += wlen;
820 if (len > XBC_KEYLEN_MAX)
821 return xbc_parse_error("Too long key length",
822 xbc_node_get_data(n));
823
824 m = xbc_node_get_child(n);
825 if (m && xbc_node_is_key(m)) {
826 n = m;
827 depth++;
828 if (depth > XBC_DEPTH_MAX)
829 return xbc_parse_error("Too many key words",
830 xbc_node_get_data(n));
831 continue;
832 }
833 len -= wlen;
834 m = xbc_node_get_next(n);
835 while (!m) {
836 n = xbc_node_get_parent(n);
837 if (!n)
838 break;
839 len -= strlen(xbc_node_get_data(n)) + 1;
840 depth--;
841 m = xbc_node_get_next(n);
842 }
843 n = m;
844 }
845
846 return 0;
847 }
848
849 /* Need to setup xbc_data and xbc_nodes before call this. */
850 static int __init xbc_parse_tree(void)
851 {
852 char *p, *q;
853 int ret = 0, c;
854
855 last_parent = NULL;
856 p = xbc_data;
857 do {
858 q = strpbrk(p, "{}=+;:\n#");
859 if (!q) {
860 p = skip_spaces(p);
861 if (*p != '\0')
862 ret = xbc_parse_error("No delimiter", p);
863 break;
864 }
865
866 c = *q;
867 *q++ = '\0';
868 switch (c) {
869 case ':':
870 case '+':
871 if (*q++ != '=') {
872 ret = xbc_parse_error(c == '+' ?
873 "Wrong '+' operator" :
874 "Wrong ':' operator",
875 q - 2);
876 break;
877 }
878 fallthrough;
879 case '=':
880 ret = xbc_parse_kv(&p, q, c);
881 break;
882 case '{':
883 ret = xbc_open_brace(&p, q);
884 break;
885 case '#':
886 q = skip_comment(q);
887 fallthrough;
888 case ';':
889 case '\n':
890 ret = xbc_parse_key(&p, q);
891 break;
892 case '}':
893 ret = xbc_close_brace(&p, q);
894 break;
895 }
896 } while (!ret);
897
898 return ret;
899 }
900
901 /**
902 * _xbc_exit() - Clean up all parsed bootconfig
903 * @early: Set true if this is called before budy system is initialized.
904 *
905 * This clears all data structures of parsed bootconfig on memory.
906 * If you need to reuse xbc_init() with new boot config, you can
907 * use this.
908 */
909 void __init _xbc_exit(bool early)
910 {
911 xbc_free_mem(xbc_data, xbc_data_size, early);
912 xbc_data = NULL;
913 xbc_data_size = 0;
914 xbc_node_num = 0;
915 xbc_free_mem(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX, early);
916 xbc_nodes = NULL;
917 brace_index = 0;
918 }
919
920 /**
921 * xbc_init() - Parse given XBC file and build XBC internal tree
922 * @data: The boot config text original data
923 * @size: The size of @data
924 * @emsg: A pointer of const char * to store the error message
925 * @epos: A pointer of int to store the error position
926 *
927 * This parses the boot config text in @data. @size must be smaller
928 * than XBC_DATA_MAX.
929 * Return the number of stored nodes (>0) if succeeded, or -errno
930 * if there is any error.
931 * In error cases, @emsg will be updated with an error message and
932 * @epos will be updated with the error position which is the byte offset
933 * of @buf. If the error is not a parser error, @epos will be -1.
934 */
935 int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos)
936 {
937 int ret;
938
939 if (epos)
940 *epos = -1;
941
942 if (xbc_data) {
943 if (emsg)
944 *emsg = "Bootconfig is already initialized";
945 return -EBUSY;
946 }
947 if (size > XBC_DATA_MAX || size == 0) {
948 if (emsg)
949 *emsg = size ? "Config data is too big" :
950 "Config data is empty";
951 return -ERANGE;
952 }
953
954 xbc_data = xbc_alloc_mem(size + 1);
955 if (!xbc_data) {
956 if (emsg)
957 *emsg = "Failed to allocate bootconfig data";
958 return -ENOMEM;
959 }
960 memcpy(xbc_data, data, size);
961 xbc_data[size] = '\0';
962 xbc_data_size = size + 1;
963
964 xbc_nodes = xbc_alloc_mem(sizeof(struct xbc_node) * XBC_NODE_MAX);
965 if (!xbc_nodes) {
966 if (emsg)
967 *emsg = "Failed to allocate bootconfig nodes";
968 _xbc_exit(true);
969 return -ENOMEM;
970 }
971 memset(xbc_nodes, 0, sizeof(struct xbc_node) * XBC_NODE_MAX);
972
973 ret = xbc_parse_tree();
974 if (!ret)
975 ret = xbc_verify_tree();
976
977 if (ret < 0) {
978 if (epos)
979 *epos = xbc_err_pos;
980 if (emsg)
981 *emsg = xbc_err_msg;
982 _xbc_exit(true);
983 } else
984 ret = xbc_node_num;
985
986 return ret;
987 }
988
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