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 void fdt_downgrade_version(void *fdt) 26 { 27 if (!can_assume(LATEST) && fdt_version(fdt) > FDT_LAST_SUPPORTED_VERSION) 28 fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION); 29 } 30 31 static int fdt_rw_probe_(void *fdt) 32 { 33 if (can_assume(VALID_DTB)) 34 return 0; 35 FDT_RO_PROBE(fdt); 36 37 if (!can_assume(LATEST) && fdt_version(fdt) < 17) 38 return -FDT_ERR_BADVERSION; 39 if (fdt_blocks_misordered_(fdt, sizeof(struct fdt_reserve_entry), 40 fdt_size_dt_struct(fdt))) 41 return -FDT_ERR_BADLAYOUT; 42 43 fdt_downgrade_version(fdt); 44 return 0; 45 } 46 47 #define FDT_RW_PROBE(fdt) \ 48 { \ 49 int err_; \ 50 if ((err_ = fdt_rw_probe_(fdt)) != 0) \ 51 return err_; \ 52 } 53 54 static inline unsigned int fdt_data_size_(void *fdt) 55 { 56 return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt); 57 } 58 59 static int fdt_splice_(void *fdt, void *splicepoint, int oldlen, int newlen) 60 { 61 char *p = splicepoint; 62 unsigned int dsize = fdt_data_size_(fdt); 63 size_t soff = p - (char *)fdt; 64 65 if ((oldlen < 0) || (soff + oldlen < soff) || (soff + oldlen > dsize)) 66 return -FDT_ERR_BADOFFSET; 67 if ((p < (char *)fdt) || (dsize + newlen < (unsigned)oldlen)) 68 return -FDT_ERR_BADOFFSET; 69 if (dsize - oldlen + newlen > fdt_totalsize(fdt)) 70 return -FDT_ERR_NOSPACE; 71 memmove(p + newlen, p + oldlen, ((char *)fdt + dsize) - (p + oldlen)); 72 return 0; 73 } 74 75 static int fdt_splice_mem_rsv_(void *fdt, struct fdt_reserve_entry *p, 76 int oldn, int newn) 77 { 78 int delta = (newn - oldn) * sizeof(*p); 79 int err; 80 err = fdt_splice_(fdt, p, oldn * sizeof(*p), newn * sizeof(*p)); 81 if (err) 82 return err; 83 fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta); 84 fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta); 85 return 0; 86 } 87 88 static int fdt_splice_struct_(void *fdt, void *p, 89 int oldlen, int newlen) 90 { 91 int delta = newlen - oldlen; 92 int err; 93 94 if ((err = fdt_splice_(fdt, p, oldlen, newlen))) 95 return err; 96 97 fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta); 98 fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta); 99 return 0; 100 } 101 102 /* Must only be used to roll back in case of error */ 103 static void fdt_del_last_string_(void *fdt, const char *s) 104 { 105 int newlen = strlen(s) + 1; 106 107 fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) - newlen); 108 } 109 110 static int fdt_splice_string_(void *fdt, int newlen) 111 { 112 void *p = (char *)fdt 113 + fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt); 114 int err; 115 116 if ((err = fdt_splice_(fdt, p, 0, newlen))) 117 return err; 118 119 fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen); 120 return 0; 121 } 122 123 /** 124 * fdt_find_add_string_() - Find or allocate a string 125 * 126 * @fdt: pointer to the device tree to check/adjust 127 * @s: string to find/add 128 * @allocated: Set to 0 if the string was found, 1 if not found and so 129 * allocated. Ignored if can_assume(NO_ROLLBACK) 130 * @return offset of string in the string table (whether found or added) 131 */ 132 static int fdt_find_add_string_(void *fdt, const char *s, int slen, 133 int *allocated) 134 { 135 char *strtab = (char *)fdt + fdt_off_dt_strings(fdt); 136 const char *p; 137 char *new; 138 int err; 139 140 if (!can_assume(NO_ROLLBACK)) 141 *allocated = 0; 142 143 p = fdt_find_string_len_(strtab, fdt_size_dt_strings(fdt), s, slen); 144 if (p) 145 /* found it */ 146 return (p - strtab); 147 148 new = strtab + fdt_size_dt_strings(fdt); 149 err = fdt_splice_string_(fdt, slen + 1); 150 if (err) 151 return err; 152 153 if (!can_assume(NO_ROLLBACK)) 154 *allocated = 1; 155 156 memcpy(new, s, slen); 157 new[slen] = '\0'; 158 159 return (new - strtab); 160 } 161 162 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size) 163 { 164 struct fdt_reserve_entry *re; 165 int err; 166 167 FDT_RW_PROBE(fdt); 168 169 re = fdt_mem_rsv_w_(fdt, fdt_num_mem_rsv(fdt)); 170 err = fdt_splice_mem_rsv_(fdt, re, 0, 1); 171 if (err) 172 return err; 173 174 re->address = cpu_to_fdt64(address); 175 re->size = cpu_to_fdt64(size); 176 return 0; 177 } 178 179 int fdt_del_mem_rsv(void *fdt, int n) 180 { 181 struct fdt_reserve_entry *re = fdt_mem_rsv_w_(fdt, n); 182 183 FDT_RW_PROBE(fdt); 184 185 if (n >= fdt_num_mem_rsv(fdt)) 186 return -FDT_ERR_NOTFOUND; 187 188 return fdt_splice_mem_rsv_(fdt, re, 1, 0); 189 } 190 191 static int fdt_resize_property_(void *fdt, int nodeoffset, 192 const char *name, int namelen, 193 int len, struct fdt_property **prop) 194 { 195 int oldlen; 196 int err; 197 198 *prop = fdt_get_property_namelen_w(fdt, nodeoffset, name, namelen, 199 &oldlen); 200 if (!*prop) 201 return oldlen; 202 203 if ((err = fdt_splice_struct_(fdt, (*prop)->data, FDT_TAGALIGN(oldlen), 204 FDT_TAGALIGN(len)))) 205 return err; 206 207 (*prop)->len = cpu_to_fdt32(len); 208 return 0; 209 } 210 211 static int fdt_add_property_(void *fdt, int nodeoffset, const char *name, 212 int namelen, int len, struct fdt_property **prop) 213 { 214 int proplen; 215 int nextoffset; 216 int namestroff; 217 int err; 218 int allocated; 219 220 if ((nextoffset = fdt_check_node_offset_(fdt, nodeoffset)) < 0) 221 return nextoffset; 222 223 namestroff = fdt_find_add_string_(fdt, name, namelen, &allocated); 224 if (namestroff < 0) 225 return namestroff; 226 227 *prop = fdt_offset_ptr_w_(fdt, nextoffset); 228 proplen = sizeof(**prop) + FDT_TAGALIGN(len); 229 230 err = fdt_splice_struct_(fdt, *prop, 0, proplen); 231 if (err) { 232 /* Delete the string if we failed to add it */ 233 if (!can_assume(NO_ROLLBACK) && allocated) 234 fdt_del_last_string_(fdt, name); 235 return err; 236 } 237 238 (*prop)->tag = cpu_to_fdt32(FDT_PROP); 239 (*prop)->nameoff = cpu_to_fdt32(namestroff); 240 (*prop)->len = cpu_to_fdt32(len); 241 return 0; 242 } 243 244 int fdt_set_name(void *fdt, int nodeoffset, const char *name) 245 { 246 char *namep; 247 int oldlen, newlen; 248 int err; 249 250 FDT_RW_PROBE(fdt); 251 252 namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen); 253 if (!namep) 254 return oldlen; 255 256 newlen = strlen(name); 257 258 err = fdt_splice_struct_(fdt, namep, FDT_TAGALIGN(oldlen+1), 259 FDT_TAGALIGN(newlen+1)); 260 if (err) 261 return err; 262 263 memcpy(namep, name, newlen+1); 264 return 0; 265 } 266 267 int fdt_setprop_placeholder_namelen(void *fdt, int nodeoffset, const char *name, 268 int namelen, int len, void **prop_data) 269 { 270 struct fdt_property *prop; 271 int err; 272 273 FDT_RW_PROBE(fdt); 274 275 err = fdt_resize_property_(fdt, nodeoffset, name, namelen, len, &prop); 276 if (err == -FDT_ERR_NOTFOUND) 277 err = fdt_add_property_(fdt, nodeoffset, name, namelen, len, 278 &prop); 279 if (err) 280 return err; 281 282 *prop_data = prop->data; 283 return 0; 284 } 285 286 int fdt_setprop_namelen(void *fdt, int nodeoffset, const char *name, 287 int namelen, const void *val, int len) 288 { 289 void *prop_data; 290 int err; 291 292 err = fdt_setprop_placeholder_namelen(fdt, nodeoffset, name, namelen, 293 len, &prop_data); 294 if (err) 295 return err; 296 297 if (len) 298 memcpy(prop_data, val, len); 299 return 0; 300 } 301 302 int fdt_appendprop(void *fdt, int nodeoffset, const char *name, 303 const void *val, int len) 304 { 305 struct fdt_property *prop; 306 int err, oldlen, newlen; 307 308 FDT_RW_PROBE(fdt); 309 310 prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen); 311 if (prop) { 312 newlen = len + oldlen; 313 err = fdt_splice_struct_(fdt, prop->data, 314 FDT_TAGALIGN(oldlen), 315 FDT_TAGALIGN(newlen)); 316 if (err) 317 return err; 318 prop->len = cpu_to_fdt32(newlen); 319 memcpy(prop->data + oldlen, val, len); 320 } else { 321 err = fdt_add_property_(fdt, nodeoffset, name, strlen(name), 322 len, &prop); 323 if (err) 324 return err; 325 memcpy(prop->data, val, len); 326 } 327 return 0; 328 } 329 330 int fdt_delprop(void *fdt, int nodeoffset, const char *name) 331 { 332 struct fdt_property *prop; 333 int len, proplen; 334 335 FDT_RW_PROBE(fdt); 336 337 prop = fdt_get_property_w(fdt, nodeoffset, name, &len); 338 if (!prop) 339 return len; 340 341 proplen = sizeof(*prop) + FDT_TAGALIGN(len); 342 return fdt_splice_struct_(fdt, prop, proplen, 0); 343 } 344 345 int fdt_add_subnode_namelen(void *fdt, int parentoffset, 346 const char *name, int namelen) 347 { 348 struct fdt_node_header *nh; 349 int offset, nextoffset; 350 int nodelen; 351 int err; 352 uint32_t tag; 353 fdt32_t *endtag; 354 355 FDT_RW_PROBE(fdt); 356 357 offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen); 358 if (offset >= 0) 359 return -FDT_ERR_EXISTS; 360 else if (offset != -FDT_ERR_NOTFOUND) 361 return offset; 362 363 /* Try to place the new node after the parent's properties */ 364 tag = fdt_next_tag(fdt, parentoffset, &nextoffset); 365 /* the fdt_subnode_offset_namelen() should ensure this never hits */ 366 if (!can_assume(LIBFDT_FLAWLESS) && (tag != FDT_BEGIN_NODE)) 367 return -FDT_ERR_INTERNAL; 368 do { 369 offset = nextoffset; 370 tag = fdt_next_tag(fdt, offset, &nextoffset); 371 } while ((tag == FDT_PROP) || (tag == FDT_NOP)); 372 373 nh = fdt_offset_ptr_w_(fdt, offset); 374 nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE; 375 376 err = fdt_splice_struct_(fdt, nh, 0, nodelen); 377 if (err) 378 return err; 379 380 nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE); 381 memset(nh->name, 0, FDT_TAGALIGN(namelen+1)); 382 memcpy(nh->name, name, namelen); 383 endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE); 384 *endtag = cpu_to_fdt32(FDT_END_NODE); 385 386 return offset; 387 } 388 389 int fdt_add_subnode(void *fdt, int parentoffset, const char *name) 390 { 391 return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name)); 392 } 393 394 int fdt_del_node(void *fdt, int nodeoffset) 395 { 396 int endoffset; 397 398 FDT_RW_PROBE(fdt); 399 400 endoffset = fdt_node_end_offset_(fdt, nodeoffset); 401 if (endoffset < 0) 402 return endoffset; 403 404 return fdt_splice_struct_(fdt, fdt_offset_ptr_w_(fdt, nodeoffset), 405 endoffset - nodeoffset, 0); 406 } 407 408 static void fdt_packblocks_(const char *old, char *new, 409 int mem_rsv_size, 410 int struct_size, 411 int strings_size) 412 { 413 int mem_rsv_off, struct_off, strings_off; 414 415 mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8); 416 struct_off = mem_rsv_off + mem_rsv_size; 417 strings_off = struct_off + struct_size; 418 419 memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size); 420 fdt_set_off_mem_rsvmap(new, mem_rsv_off); 421 422 memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size); 423 fdt_set_off_dt_struct(new, struct_off); 424 fdt_set_size_dt_struct(new, struct_size); 425 426 memmove(new + strings_off, old + fdt_off_dt_strings(old), strings_size); 427 fdt_set_off_dt_strings(new, strings_off); 428 fdt_set_size_dt_strings(new, fdt_size_dt_strings(old)); 429 } 430 431 int fdt_open_into(const void *fdt, void *buf, int bufsize) 432 { 433 int err; 434 int mem_rsv_size, struct_size; 435 int newsize; 436 const char *fdtstart = fdt; 437 const char *fdtend = fdtstart + fdt_totalsize(fdt); 438 char *tmp; 439 440 FDT_RO_PROBE(fdt); 441 442 mem_rsv_size = (fdt_num_mem_rsv(fdt)+1) 443 * sizeof(struct fdt_reserve_entry); 444 445 if (can_assume(LATEST) || fdt_version(fdt) >= 17) { 446 struct_size = fdt_size_dt_struct(fdt); 447 } else if (fdt_version(fdt) == 16) { 448 struct_size = 0; 449 while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END) 450 ; 451 if (struct_size < 0) 452 return struct_size; 453 } else { 454 return -FDT_ERR_BADVERSION; 455 } 456 457 if (can_assume(LIBFDT_ORDER) || 458 !fdt_blocks_misordered_(fdt, mem_rsv_size, struct_size)) { 459 /* no further work necessary */ 460 err = fdt_move(fdt, buf, bufsize); 461 if (err) 462 return err; 463 fdt_set_version(buf, 17); 464 fdt_set_size_dt_struct(buf, struct_size); 465 fdt_set_totalsize(buf, bufsize); 466 return 0; 467 } 468 469 /* Need to reorder */ 470 newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size 471 + struct_size + fdt_size_dt_strings(fdt); 472 473 if (bufsize < newsize) 474 return -FDT_ERR_NOSPACE; 475 476 /* First attempt to build converted tree at beginning of buffer */ 477 tmp = buf; 478 /* But if that overlaps with the old tree... */ 479 if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) { 480 /* Try right after the old tree instead */ 481 tmp = (char *)(uintptr_t)fdtend; 482 if ((tmp + newsize) > ((char *)buf + bufsize)) 483 return -FDT_ERR_NOSPACE; 484 } 485 486 fdt_packblocks_(fdt, tmp, mem_rsv_size, struct_size, 487 fdt_size_dt_strings(fdt)); 488 memmove(buf, tmp, newsize); 489 490 fdt_set_magic(buf, FDT_MAGIC); 491 fdt_set_totalsize(buf, bufsize); 492 fdt_set_version(buf, 17); 493 fdt_set_last_comp_version(buf, 16); 494 fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt)); 495 496 return 0; 497 } 498 499 int fdt_pack(void *fdt) 500 { 501 int mem_rsv_size; 502 503 FDT_RW_PROBE(fdt); 504 505 mem_rsv_size = (fdt_num_mem_rsv(fdt)+1) 506 * sizeof(struct fdt_reserve_entry); 507 fdt_packblocks_(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt), 508 fdt_size_dt_strings(fdt)); 509 fdt_set_totalsize(fdt, fdt_data_size_(fdt)); 510 511 return 0; 512 } 513