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 slen, 128 int *allocated) 129 { 130 char *strtab = (char *)fdt + fdt_off_dt_strings(fdt); 131 const char *p; 132 char *new; 133 int err; 134 135 if (!can_assume(NO_ROLLBACK)) 136 *allocated = 0; 137 138 p = fdt_find_string_len_(strtab, fdt_size_dt_strings(fdt), s, slen); 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, slen + 1); 145 if (err) 146 return err; 147 148 if (!can_assume(NO_ROLLBACK)) 149 *allocated = 1; 150 151 memcpy(new, s, slen); 152 new[slen] = '\0'; 153 154 return (new - strtab); 155 } 156 157 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size) 158 { 159 struct fdt_reserve_entry *re; 160 int err; 161 162 FDT_RW_PROBE(fdt); 163 164 re = fdt_mem_rsv_w_(fdt, fdt_num_mem_rsv(fdt)); 165 err = fdt_splice_mem_rsv_(fdt, re, 0, 1); 166 if (err) 167 return err; 168 169 re->address = cpu_to_fdt64(address); 170 re->size = cpu_to_fdt64(size); 171 return 0; 172 } 173 174 int fdt_del_mem_rsv(void *fdt, int n) 175 { 176 struct fdt_reserve_entry *re = fdt_mem_rsv_w_(fdt, n); 177 178 FDT_RW_PROBE(fdt); 179 180 if (n >= fdt_num_mem_rsv(fdt)) 181 return -FDT_ERR_NOTFOUND; 182 183 return fdt_splice_mem_rsv_(fdt, re, 1, 0); 184 } 185 186 static int fdt_resize_property_(void *fdt, int nodeoffset, 187 const char *name, int namelen, 188 int len, struct fdt_property **prop) 189 { 190 int oldlen; 191 int err; 192 193 *prop = fdt_get_property_namelen_w(fdt, nodeoffset, name, namelen, 194 &oldlen); 195 if (!*prop) 196 return oldlen; 197 198 if ((err = fdt_splice_struct_(fdt, (*prop)->data, FDT_TAGALIGN(oldlen), 199 FDT_TAGALIGN(len)))) 200 return err; 201 202 (*prop)->len = cpu_to_fdt32(len); 203 return 0; 204 } 205 206 static int fdt_add_property_(void *fdt, int nodeoffset, const char *name, 207 int namelen, int len, struct fdt_property **prop) 208 { 209 int proplen; 210 int nextoffset; 211 int namestroff; 212 int err; 213 int allocated; 214 215 if ((nextoffset = fdt_check_node_offset_(fdt, nodeoffset)) < 0) 216 return nextoffset; 217 218 namestroff = fdt_find_add_string_(fdt, name, namelen, &allocated); 219 if (namestroff < 0) 220 return namestroff; 221 222 *prop = fdt_offset_ptr_w_(fdt, nextoffset); 223 proplen = sizeof(**prop) + FDT_TAGALIGN(len); 224 225 err = fdt_splice_struct_(fdt, *prop, 0, proplen); 226 if (err) { 227 /* Delete the string if we failed to add it */ 228 if (!can_assume(NO_ROLLBACK) && allocated) 229 fdt_del_last_string_(fdt, name); 230 return err; 231 } 232 233 (*prop)->tag = cpu_to_fdt32(FDT_PROP); 234 (*prop)->nameoff = cpu_to_fdt32(namestroff); 235 (*prop)->len = cpu_to_fdt32(len); 236 return 0; 237 } 238 239 int fdt_set_name(void *fdt, int nodeoffset, const char *name) 240 { 241 char *namep; 242 int oldlen, newlen; 243 int err; 244 245 FDT_RW_PROBE(fdt); 246 247 namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen); 248 if (!namep) 249 return oldlen; 250 251 newlen = strlen(name); 252 253 err = fdt_splice_struct_(fdt, namep, FDT_TAGALIGN(oldlen+1), 254 FDT_TAGALIGN(newlen+1)); 255 if (err) 256 return err; 257 258 memcpy(namep, name, newlen+1); 259 return 0; 260 } 261 262 int fdt_setprop_placeholder_namelen(void *fdt, int nodeoffset, const char *name, 263 int namelen, int len, void **prop_data) 264 { 265 struct fdt_property *prop; 266 int err; 267 268 FDT_RW_PROBE(fdt); 269 270 err = fdt_resize_property_(fdt, nodeoffset, name, namelen, len, &prop); 271 if (err == -FDT_ERR_NOTFOUND) 272 err = fdt_add_property_(fdt, nodeoffset, name, namelen, len, 273 &prop); 274 if (err) 275 return err; 276 277 *prop_data = prop->data; 278 return 0; 279 } 280 281 int fdt_setprop_namelen(void *fdt, int nodeoffset, const char *name, 282 int namelen, const void *val, int len) 283 { 284 void *prop_data; 285 int err; 286 287 err = fdt_setprop_placeholder_namelen(fdt, nodeoffset, name, namelen, 288 len, &prop_data); 289 if (err) 290 return err; 291 292 if (len) 293 memcpy(prop_data, val, len); 294 return 0; 295 } 296 297 int fdt_appendprop(void *fdt, int nodeoffset, const char *name, 298 const void *val, int len) 299 { 300 struct fdt_property *prop; 301 int err, oldlen, newlen; 302 303 FDT_RW_PROBE(fdt); 304 305 prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen); 306 if (prop) { 307 newlen = len + oldlen; 308 err = fdt_splice_struct_(fdt, prop->data, 309 FDT_TAGALIGN(oldlen), 310 FDT_TAGALIGN(newlen)); 311 if (err) 312 return err; 313 prop->len = cpu_to_fdt32(newlen); 314 memcpy(prop->data + oldlen, val, len); 315 } else { 316 err = fdt_add_property_(fdt, nodeoffset, name, strlen(name), 317 len, &prop); 318 if (err) 319 return err; 320 memcpy(prop->data, val, len); 321 } 322 return 0; 323 } 324 325 int fdt_delprop(void *fdt, int nodeoffset, const char *name) 326 { 327 struct fdt_property *prop; 328 int len, proplen; 329 330 FDT_RW_PROBE(fdt); 331 332 prop = fdt_get_property_w(fdt, nodeoffset, name, &len); 333 if (!prop) 334 return len; 335 336 proplen = sizeof(*prop) + FDT_TAGALIGN(len); 337 return fdt_splice_struct_(fdt, prop, proplen, 0); 338 } 339 340 int fdt_add_subnode_namelen(void *fdt, int parentoffset, 341 const char *name, int namelen) 342 { 343 struct fdt_node_header *nh; 344 int offset, nextoffset; 345 int nodelen; 346 int err; 347 uint32_t tag; 348 fdt32_t *endtag; 349 350 FDT_RW_PROBE(fdt); 351 352 offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen); 353 if (offset >= 0) 354 return -FDT_ERR_EXISTS; 355 else if (offset != -FDT_ERR_NOTFOUND) 356 return offset; 357 358 /* Try to place the new node after the parent's properties */ 359 tag = fdt_next_tag(fdt, parentoffset, &nextoffset); 360 /* the fdt_subnode_offset_namelen() should ensure this never hits */ 361 if (!can_assume(LIBFDT_FLAWLESS) && (tag != FDT_BEGIN_NODE)) 362 return -FDT_ERR_INTERNAL; 363 do { 364 offset = nextoffset; 365 tag = fdt_next_tag(fdt, offset, &nextoffset); 366 } while ((tag == FDT_PROP) || (tag == FDT_NOP)); 367 368 nh = fdt_offset_ptr_w_(fdt, offset); 369 nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE; 370 371 err = fdt_splice_struct_(fdt, nh, 0, nodelen); 372 if (err) 373 return err; 374 375 nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE); 376 memset(nh->name, 0, FDT_TAGALIGN(namelen+1)); 377 memcpy(nh->name, name, namelen); 378 endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE); 379 *endtag = cpu_to_fdt32(FDT_END_NODE); 380 381 return offset; 382 } 383 384 int fdt_add_subnode(void *fdt, int parentoffset, const char *name) 385 { 386 return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name)); 387 } 388 389 int fdt_del_node(void *fdt, int nodeoffset) 390 { 391 int endoffset; 392 393 FDT_RW_PROBE(fdt); 394 395 endoffset = fdt_node_end_offset_(fdt, nodeoffset); 396 if (endoffset < 0) 397 return endoffset; 398 399 return fdt_splice_struct_(fdt, fdt_offset_ptr_w_(fdt, nodeoffset), 400 endoffset - nodeoffset, 0); 401 } 402 403 static void fdt_packblocks_(const char *old, char *new, 404 int mem_rsv_size, 405 int struct_size, 406 int strings_size) 407 { 408 int mem_rsv_off, struct_off, strings_off; 409 410 mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8); 411 struct_off = mem_rsv_off + mem_rsv_size; 412 strings_off = struct_off + struct_size; 413 414 memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size); 415 fdt_set_off_mem_rsvmap(new, mem_rsv_off); 416 417 memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size); 418 fdt_set_off_dt_struct(new, struct_off); 419 fdt_set_size_dt_struct(new, struct_size); 420 421 memmove(new + strings_off, old + fdt_off_dt_strings(old), strings_size); 422 fdt_set_off_dt_strings(new, strings_off); 423 fdt_set_size_dt_strings(new, fdt_size_dt_strings(old)); 424 } 425 426 int fdt_open_into(const void *fdt, void *buf, int bufsize) 427 { 428 int err; 429 int mem_rsv_size, struct_size; 430 int newsize; 431 const char *fdtstart = fdt; 432 const char *fdtend = fdtstart + fdt_totalsize(fdt); 433 char *tmp; 434 435 FDT_RO_PROBE(fdt); 436 437 mem_rsv_size = (fdt_num_mem_rsv(fdt)+1) 438 * sizeof(struct fdt_reserve_entry); 439 440 if (can_assume(LATEST) || fdt_version(fdt) >= 17) { 441 struct_size = fdt_size_dt_struct(fdt); 442 } else if (fdt_version(fdt) == 16) { 443 struct_size = 0; 444 while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END) 445 ; 446 if (struct_size < 0) 447 return struct_size; 448 } else { 449 return -FDT_ERR_BADVERSION; 450 } 451 452 if (can_assume(LIBFDT_ORDER) || 453 !fdt_blocks_misordered_(fdt, mem_rsv_size, struct_size)) { 454 /* no further work necessary */ 455 err = fdt_move(fdt, buf, bufsize); 456 if (err) 457 return err; 458 fdt_set_version(buf, 17); 459 fdt_set_size_dt_struct(buf, struct_size); 460 fdt_set_totalsize(buf, bufsize); 461 return 0; 462 } 463 464 /* Need to reorder */ 465 newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size 466 + struct_size + fdt_size_dt_strings(fdt); 467 468 if (bufsize < newsize) 469 return -FDT_ERR_NOSPACE; 470 471 /* First attempt to build converted tree at beginning of buffer */ 472 tmp = buf; 473 /* But if that overlaps with the old tree... */ 474 if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) { 475 /* Try right after the old tree instead */ 476 tmp = (char *)(uintptr_t)fdtend; 477 if ((tmp + newsize) > ((char *)buf + bufsize)) 478 return -FDT_ERR_NOSPACE; 479 } 480 481 fdt_packblocks_(fdt, tmp, mem_rsv_size, struct_size, 482 fdt_size_dt_strings(fdt)); 483 memmove(buf, tmp, newsize); 484 485 fdt_set_magic(buf, FDT_MAGIC); 486 fdt_set_totalsize(buf, bufsize); 487 fdt_set_version(buf, 17); 488 fdt_set_last_comp_version(buf, 16); 489 fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt)); 490 491 return 0; 492 } 493 494 int fdt_pack(void *fdt) 495 { 496 int mem_rsv_size; 497 498 FDT_RW_PROBE(fdt); 499 500 mem_rsv_size = (fdt_num_mem_rsv(fdt)+1) 501 * sizeof(struct fdt_reserve_entry); 502 fdt_packblocks_(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt), 503 fdt_size_dt_strings(fdt)); 504 fdt_set_totalsize(fdt, fdt_data_size_(fdt)); 505 506 return 0; 507 } 508