scripts/dtc/libfdt/fdt_rw.c

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