1 // SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
2 /*
3 * libfdt - Flat Device Tree manipulation
4 * Copyright (C) 2006 David Gibson, IBM Corporation.
5 */
6 #include "libfdt_env.h"
7
8 #include <fdt.h>
9 #include <libfdt.h>
10
11 #include "libfdt_internal.h"
12
13 static int fdt_blocks_misordered_(const void *fdt,
14 int mem_rsv_size, int struct_size)
15 {
16 return (fdt_off_mem_rsvmap(fdt) < FDT_ALIGN(sizeof(struct fdt_header), 8))
17 || (fdt_off_dt_struct(fdt) <
18 (fdt_off_mem_rsvmap(fdt) + mem_rsv_size))
19 || (fdt_off_dt_strings(fdt) <
20 (fdt_off_dt_struct(fdt) + struct_size))
21 || (fdt_totalsize(fdt) <
22 (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
23 }
24
25 static int fdt_rw_probe_(void *fdt)
26 {
27 if (can_assume(VALID_DTB))
28 return 0;
29 FDT_RO_PROBE(fdt);
30
31 if (!can_assume(LATEST) && fdt_version(fdt) < 17)
32 return -FDT_ERR_BADVERSION;
33 if (fdt_blocks_misordered_(fdt, sizeof(struct fdt_reserve_entry),
34 fdt_size_dt_struct(fdt)))
35 return -FDT_ERR_BADLAYOUT;
36 if (!can_assume(LATEST) && fdt_version(fdt) > 17)
37 fdt_set_version(fdt, 17);
38
39 return 0;
40 }
41
42 #define FDT_RW_PROBE(fdt) \
43 { \
44 int err_; \
45 if ((err_ = fdt_rw_probe_(fdt)) != 0) \
46 return err_; \
47 }
48
49 static inline unsigned int fdt_data_size_(void *fdt)
50 {
51 return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
52 }
53
54 static int fdt_splice_(void *fdt, void *splicepoint, int oldlen, int newlen)
55 {
56 char *p = splicepoint;
57 unsigned int dsize = fdt_data_size_(fdt);
58 size_t soff = p - (char *)fdt;
59
60 if ((oldlen < 0) || (soff + oldlen < soff) || (soff + oldlen > dsize))
61 return -FDT_ERR_BADOFFSET;
62 if ((p < (char *)fdt) || (dsize + newlen < (unsigned)oldlen))
63 return -FDT_ERR_BADOFFSET;
64 if (dsize - oldlen + newlen > fdt_totalsize(fdt))
65 return -FDT_ERR_NOSPACE;
66 memmove(p + newlen, p + oldlen, ((char *)fdt + dsize) - (p + oldlen));
67 return 0;
68 }
69
70 static int fdt_splice_mem_rsv_(void *fdt, struct fdt_reserve_entry *p,
71 int oldn, int newn)
72 {
73 int delta = (newn - oldn) * sizeof(*p);
74 int err;
75 err = fdt_splice_(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
76 if (err)
77 return err;
78 fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
79 fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
80 return 0;
81 }
82
83 static int fdt_splice_struct_(void *fdt, void *p,
84 int oldlen, int newlen)
85 {
86 int delta = newlen - oldlen;
87 int err;
88
89 if ((err = fdt_splice_(fdt, p, oldlen, newlen)))
90 return err;
91
92 fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
93 fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
94 return 0;
95 }
96
97 /* Must only be used to roll back in case of error */
98 static void fdt_del_last_string_(void *fdt, const char *s)
99 {
100 int newlen = strlen(s) + 1;
101
102 fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) - newlen);
103 }
104
105 static int fdt_splice_string_(void *fdt, int newlen)
106 {
107 void *p = (char *)fdt
108 + fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
109 int err;
110
111 if ((err = fdt_splice_(fdt, p, 0, newlen)))
112 return err;
113
114 fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
115 return 0;
116 }
117
118 /**
119 * fdt_find_add_string_() - Find or allocate a string
120 *
121 * @fdt: pointer to the device tree to check/adjust
122 * @s: string to find/add
123 * @allocated: Set to 0 if the string was found, 1 if not found and so
124 * allocated. Ignored if can_assume(NO_ROLLBACK)
125 * @return offset of string in the string table (whether found or added)
126 */
127 static int fdt_find_add_string_(void *fdt, const char *s, int *allocated)
128 {
129 char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
130 const char *p;
131 char *new;
132 int len = strlen(s) + 1;
133 int err;
134
135 if (!can_assume(NO_ROLLBACK))
136 *allocated = 0;
137
138 p = fdt_find_string_(strtab, fdt_size_dt_strings(fdt), s);
139 if (p)
140 /* found it */
141 return (p - strtab);
142
143 new = strtab + fdt_size_dt_strings(fdt);
144 err = fdt_splice_string_(fdt, len);
145 if (err)
146 return err;
147
148 if (!can_assume(NO_ROLLBACK))
149 *allocated = 1;
150
151 memcpy(new, s, len);
152 return (new - strtab);
153 }
154
155 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
156 {
157 struct fdt_reserve_entry *re;
158 int err;
159
160 FDT_RW_PROBE(fdt);
161
162 re = fdt_mem_rsv_w_(fdt, fdt_num_mem_rsv(fdt));
163 err = fdt_splice_mem_rsv_(fdt, re, 0, 1);
164 if (err)
165 return err;
166
167 re->address = cpu_to_fdt64(address);
168 re->size = cpu_to_fdt64(size);
169 return 0;
170 }
171
172 int fdt_del_mem_rsv(void *fdt, int n)
173 {
174 struct fdt_reserve_entry *re = fdt_mem_rsv_w_(fdt, n);
175
176 FDT_RW_PROBE(fdt);
177
178 if (n >= fdt_num_mem_rsv(fdt))
179 return -FDT_ERR_NOTFOUND;
180
181 return fdt_splice_mem_rsv_(fdt, re, 1, 0);
182 }
183
184 static int fdt_resize_property_(void *fdt, int nodeoffset, const char *name,
185 int len, struct fdt_property **prop)
186 {
187 int oldlen;
188 int err;
189
190 *prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
191 if (!*prop)
192 return oldlen;
193
194 if ((err = fdt_splice_struct_(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
195 FDT_TAGALIGN(len))))
196 return err;
197
198 (*prop)->len = cpu_to_fdt32(len);
199 return 0;
200 }
201
202 static int fdt_add_property_(void *fdt, int nodeoffset, const char *name,
203 int len, struct fdt_property **prop)
204 {
205 int proplen;
206 int nextoffset;
207 int namestroff;
208 int err;
209 int allocated;
210
211 if ((nextoffset = fdt_check_node_offset_(fdt, nodeoffset)) < 0)
212 return nextoffset;
213
214 namestroff = fdt_find_add_string_(fdt, name, &allocated);
215 if (namestroff < 0)
216 return namestroff;
217
218 *prop = fdt_offset_ptr_w_(fdt, nextoffset);
219 proplen = sizeof(**prop) + FDT_TAGALIGN(len);
220
221 err = fdt_splice_struct_(fdt, *prop, 0, proplen);
222 if (err) {
223 /* Delete the string if we failed to add it */
224 if (!can_assume(NO_ROLLBACK) && allocated)
225 fdt_del_last_string_(fdt, name);
226 return err;
227 }
228
229 (*prop)->tag = cpu_to_fdt32(FDT_PROP);
230 (*prop)->nameoff = cpu_to_fdt32(namestroff);
231 (*prop)->len = cpu_to_fdt32(len);
232 return 0;
233 }
234
235 int fdt_set_name(void *fdt, int nodeoffset, const char *name)
236 {
237 char *namep;
238 int oldlen, newlen;
239 int err;
240
241 FDT_RW_PROBE(fdt);
242
243 namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
244 if (!namep)
245 return oldlen;
246
247 newlen = strlen(name);
248
249 err = fdt_splice_struct_(fdt, namep, FDT_TAGALIGN(oldlen+1),
250 FDT_TAGALIGN(newlen+1));
251 if (err)
252 return err;
253
254 memcpy(namep, name, newlen+1);
255 return 0;
256 }
257
258 int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
259 int len, void **prop_data)
260 {
261 struct fdt_property *prop;
262 int err;
263
264 FDT_RW_PROBE(fdt);
265
266 err = fdt_resize_property_(fdt, nodeoffset, name, len, &prop);
267 if (err == -FDT_ERR_NOTFOUND)
268 err = fdt_add_property_(fdt, nodeoffset, name, len, &prop);
269 if (err)
270 return err;
271
272 *prop_data = prop->data;
273 return 0;
274 }
275
276 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
277 const void *val, int len)
278 {
279 void *prop_data;
280 int err;
281
282 err = fdt_setprop_placeholder(fdt, nodeoffset, name, len, &prop_data);
283 if (err)
284 return err;
285
286 if (len)
287 memcpy(prop_data, val, len);
288 return 0;
289 }
290
291 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
292 const void *val, int len)
293 {
294 struct fdt_property *prop;
295 int err, oldlen, newlen;
296
297 FDT_RW_PROBE(fdt);
298
299 prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
300 if (prop) {
301 newlen = len + oldlen;
302 err = fdt_splice_struct_(fdt, prop->data,
303 FDT_TAGALIGN(oldlen),
304 FDT_TAGALIGN(newlen));
305 if (err)
306 return err;
307 prop->len = cpu_to_fdt32(newlen);
308 memcpy(prop->data + oldlen, val, len);
309 } else {
310 err = fdt_add_property_(fdt, nodeoffset, name, len, &prop);
311 if (err)
312 return err;
313 memcpy(prop->data, val, len);
314 }
315 return 0;
316 }
317
318 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
319 {
320 struct fdt_property *prop;
321 int len, proplen;
322
323 FDT_RW_PROBE(fdt);
324
325 prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
326 if (!prop)
327 return len;
328
329 proplen = sizeof(*prop) + FDT_TAGALIGN(len);
330 return fdt_splice_struct_(fdt, prop, proplen, 0);
331 }
332
333 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
334 const char *name, int namelen)
335 {
336 struct fdt_node_header *nh;
337 int offset, nextoffset;
338 int nodelen;
339 int err;
340 uint32_t tag;
341 fdt32_t *endtag;
342
343 FDT_RW_PROBE(fdt);
344
345 offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
346 if (offset >= 0)
347 return -FDT_ERR_EXISTS;
348 else if (offset != -FDT_ERR_NOTFOUND)
349 return offset;
350
351 /* Try to place the new node after the parent's properties */
352 tag = fdt_next_tag(fdt, parentoffset, &nextoffset);
353 /* the fdt_subnode_offset_namelen() should ensure this never hits */
354 if (!can_assume(LIBFDT_FLAWLESS) && (tag != FDT_BEGIN_NODE))
355 return -FDT_ERR_INTERNAL;
356 do {
357 offset = nextoffset;
358 tag = fdt_next_tag(fdt, offset, &nextoffset);
359 } while ((tag == FDT_PROP) || (tag == FDT_NOP));
360
361 nh = fdt_offset_ptr_w_(fdt, offset);
362 nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
363
364 err = fdt_splice_struct_(fdt, nh, 0, nodelen);
365 if (err)
366 return err;
367
368 nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
369 memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
370 memcpy(nh->name, name, namelen);
371 endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
372 *endtag = cpu_to_fdt32(FDT_END_NODE);
373
374 return offset;
375 }
376
377 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
378 {
379 return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
380 }
381
382 int fdt_del_node(void *fdt, int nodeoffset)
383 {
384 int endoffset;
385
386 FDT_RW_PROBE(fdt);
387
388 endoffset = fdt_node_end_offset_(fdt, nodeoffset);
389 if (endoffset < 0)
390 return endoffset;
391
392 return fdt_splice_struct_(fdt, fdt_offset_ptr_w_(fdt, nodeoffset),
393 endoffset - nodeoffset, 0);
394 }
395
396 static void fdt_packblocks_(const char *old, char *new,
397 int mem_rsv_size,
398 int struct_size,
399 int strings_size)
400 {
401 int mem_rsv_off, struct_off, strings_off;
402
403 mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
404 struct_off = mem_rsv_off + mem_rsv_size;
405 strings_off = struct_off + struct_size;
406
407 memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
408 fdt_set_off_mem_rsvmap(new, mem_rsv_off);
409
410 memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
411 fdt_set_off_dt_struct(new, struct_off);
412 fdt_set_size_dt_struct(new, struct_size);
413
414 memmove(new + strings_off, old + fdt_off_dt_strings(old), strings_size);
415 fdt_set_off_dt_strings(new, strings_off);
416 fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
417 }
418
419 int fdt_open_into(const void *fdt, void *buf, int bufsize)
420 {
421 int err;
422 int mem_rsv_size, struct_size;
423 int newsize;
424 const char *fdtstart = fdt;
425 const char *fdtend = fdtstart + fdt_totalsize(fdt);
426 char *tmp;
427
428 FDT_RO_PROBE(fdt);
429
430 mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
431 * sizeof(struct fdt_reserve_entry);
432
433 if (can_assume(LATEST) || fdt_version(fdt) >= 17) {
434 struct_size = fdt_size_dt_struct(fdt);
435 } else if (fdt_version(fdt) == 16) {
436 struct_size = 0;
437 while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
438 ;
439 if (struct_size < 0)
440 return struct_size;
441 } else {
442 return -FDT_ERR_BADVERSION;
443 }
444
445 if (can_assume(LIBFDT_ORDER) ||
446 !fdt_blocks_misordered_(fdt, mem_rsv_size, struct_size)) {
447 /* no further work necessary */
448 err = fdt_move(fdt, buf, bufsize);
449 if (err)
450 return err;
451 fdt_set_version(buf, 17);
452 fdt_set_size_dt_struct(buf, struct_size);
453 fdt_set_totalsize(buf, bufsize);
454 return 0;
455 }
456
457 /* Need to reorder */
458 newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
459 + struct_size + fdt_size_dt_strings(fdt);
460
461 if (bufsize < newsize)
462 return -FDT_ERR_NOSPACE;
463
464 /* First attempt to build converted tree at beginning of buffer */
465 tmp = buf;
466 /* But if that overlaps with the old tree... */
467 if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
468 /* Try right after the old tree instead */
469 tmp = (char *)(uintptr_t)fdtend;
470 if ((tmp + newsize) > ((char *)buf + bufsize))
471 return -FDT_ERR_NOSPACE;
472 }
473
474 fdt_packblocks_(fdt, tmp, mem_rsv_size, struct_size,
475 fdt_size_dt_strings(fdt));
476 memmove(buf, tmp, newsize);
477
478 fdt_set_magic(buf, FDT_MAGIC);
479 fdt_set_totalsize(buf, bufsize);
480 fdt_set_version(buf, 17);
481 fdt_set_last_comp_version(buf, 16);
482 fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
483
484 return 0;
485 }
486
487 int fdt_pack(void *fdt)
488 {
489 int mem_rsv_size;
490
491 FDT_RW_PROBE(fdt);
492
493 mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
494 * sizeof(struct fdt_reserve_entry);
495 fdt_packblocks_(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt),
496 fdt_size_dt_strings(fdt));
497 fdt_set_totalsize(fdt, fdt_data_size_(fdt));
498
499 return 0;
500 }
501
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