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