scripts/mod/modpost.c

   1 /* Postprocess module symbol versions
   2  *
   3  * Copyright 2003       Kai Germaschewski
   4  * Copyright 2002-2004  Rusty Russell, IBM Corporation
   5  * Copyright 2006-2008  Sam Ravnborg
   6  * Based in part on module-init-tools/depmod.c,file2alias
   7  *
   8  * This software may be used and distributed according to the terms
   9  * of the GNU General Public License, incorporated herein by reference.
  10  *
  11  * Usage: modpost vmlinux module1.o module2.o ...
  12  */
  13
  14 #define _GNU_SOURCE
  15 #include <elf.h>
  16 #include <fnmatch.h>
  17 #include <stdio.h>
  18 #include <ctype.h>
  19 #include <string.h>
  20 #include <limits.h>
  21 #include <stdbool.h>
  22 #include <errno.h>
  23
  24 #include <hashtable.h>
  25 #include <list.h>
  26 #include "modpost.h"
  27 #include "../../include/linux/license.h"
  28
  29 static bool module_enabled;
  30 /* Are we using CONFIG_MODVERSIONS? */
  31 static bool modversions;
  32 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
  33 static bool all_versions;
  34 /* If we are modposting external module set to 1 */
  35 static bool external_module;
  36 /* Only warn about unresolved symbols */
  37 static bool warn_unresolved;
  38
  39 static int sec_mismatch_count;
  40 static bool sec_mismatch_warn_only = true;
  41 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
  42 static bool trim_unused_exports;
  43
  44 /* ignore missing files */
  45 static bool ignore_missing_files;
  46 /* If set to 1, only warn (instead of error) about missing ns imports */
  47 static bool allow_missing_ns_imports;
  48
  49 static bool error_occurred;
  50
  51 static bool extra_warn;
  52
  53 /*
  54  * Cut off the warnings when there are too many. This typically occurs when
  55  * vmlinux is missing. ('make modules' without building vmlinux.)
  56  */
  57 #define MAX_UNRESOLVED_REPORTS  10
  58 static unsigned int nr_unresolved;
  59
  60 /* In kernel, this size is defined in linux/module.h;
  61  * here we use Elf_Addr instead of long for covering cross-compile
  62  */
  63
  64 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
  65
  66 void modpost_log(enum loglevel loglevel, const char *fmt, ...)
  67 {
  68         va_list arglist;
  69
  70         switch (loglevel) {
  71         case LOG_WARN:
  72                 fprintf(stderr, "WARNING: ");
  73                 break;
  74         case LOG_ERROR:
  75                 fprintf(stderr, "ERROR: ");
  76                 error_occurred = true;
  77                 break;
  78         default: /* invalid loglevel, ignore */
  79                 break;
  80         }
  81
  82         fprintf(stderr, "modpost: ");
  83
  84         va_start(arglist, fmt);
  85         vfprintf(stderr, fmt, arglist);
  86         va_end(arglist);
  87 }
  88
  89 static inline bool strends(const char *str, const char *postfix)
  90 {
  91         if (strlen(str) < strlen(postfix))
  92                 return false;
  93
  94         return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
  95 }
  96
  97 void *do_nofail(void *ptr, const char *expr)
  98 {
  99         if (!ptr)
 100                 fatal("Memory allocation failure: %s.\n", expr);
 101
 102         return ptr;
 103 }
 104
 105 char *read_text_file(const char *filename)
 106 {
 107         struct stat st;
 108         size_t nbytes;
 109         int fd;
 110         char *buf;
 111
 112         fd = open(filename, O_RDONLY);
 113         if (fd < 0) {
 114                 perror(filename);
 115                 exit(1);
 116         }
 117
 118         if (fstat(fd, &st) < 0) {
 119                 perror(filename);
 120                 exit(1);
 121         }
 122
 123         buf = NOFAIL(malloc(st.st_size + 1));
 124
 125         nbytes = st.st_size;
 126
 127         while (nbytes) {
 128                 ssize_t bytes_read;
 129
 130                 bytes_read = read(fd, buf, nbytes);
 131                 if (bytes_read < 0) {
 132                         perror(filename);
 133                         exit(1);
 134                 }
 135
 136                 nbytes -= bytes_read;
 137         }
 138         buf[st.st_size] = '\0';
 139
 140         close(fd);
 141
 142         return buf;
 143 }
 144
 145 char *get_line(char **stringp)
 146 {
 147         char *orig = *stringp, *next;
 148
 149         /* do not return the unwanted extra line at EOF */
 150         if (!orig || *orig == '\0')
 151                 return NULL;
 152
 153         /* don't use strsep here, it is not available everywhere */
 154         next = strchr(orig, '\n');
 155         if (next)
 156                 *next++ = '\0';
 157
 158         *stringp = next;
 159
 160         return orig;
 161 }
 162
 163 /* A list of all modules we processed */
 164 LIST_HEAD(modules);
 165
 166 static struct module *find_module(const char *modname)
 167 {
 168         struct module *mod;
 169
 170         list_for_each_entry(mod, &modules, list) {
 171                 if (strcmp(mod->name, modname) == 0)
 172                         return mod;
 173         }
 174         return NULL;
 175 }
 176
 177 static struct module *new_module(const char *name, size_t namelen)
 178 {
 179         struct module *mod;
 180
 181         mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1));
 182         memset(mod, 0, sizeof(*mod));
 183
 184         INIT_LIST_HEAD(&mod->exported_symbols);
 185         INIT_LIST_HEAD(&mod->unresolved_symbols);
 186         INIT_LIST_HEAD(&mod->missing_namespaces);
 187         INIT_LIST_HEAD(&mod->imported_namespaces);
 188
 189         memcpy(mod->name, name, namelen);
 190         mod->name[namelen] = '\0';
 191         mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
 192
 193         /*
 194          * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
 195          * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
 196          * modpost will exit wiht error anyway.
 197          */
 198         mod->is_gpl_compatible = true;
 199
 200         list_add_tail(&mod->list, &modules);
 201
 202         return mod;
 203 }
 204
 205 struct symbol {
 206         struct hlist_node hnode;/* link to hash table */
 207         struct list_head list;  /* link to module::exported_symbols or module::unresolved_symbols */
 208         struct module *module;
 209         char *namespace;
 210         unsigned int crc;
 211         bool crc_valid;
 212         bool weak;
 213         bool is_func;
 214         bool is_gpl_only;       /* exported by EXPORT_SYMBOL_GPL */
 215         bool used;              /* there exists a user of this symbol */
 216         char name[];
 217 };
 218
 219 static HASHTABLE_DEFINE(symbol_hashtable, 1U << 10);
 220
 221 /* This is based on the hash algorithm from gdbm, via tdb */
 222 static inline unsigned int tdb_hash(const char *name)
 223 {
 224         unsigned value; /* Used to compute the hash value.  */
 225         unsigned   i;   /* Used to cycle through random values. */
 226
 227         /* Set the initial value from the key size. */
 228         for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
 229                 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
 230
 231         return (1103515243 * value + 12345);
 232 }
 233
 234 /**
 235  * Allocate a new symbols for use in the hash of exported symbols or
 236  * the list of unresolved symbols per module
 237  **/
 238 static struct symbol *alloc_symbol(const char *name)
 239 {
 240         struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
 241
 242         memset(s, 0, sizeof(*s));
 243         strcpy(s->name, name);
 244
 245         return s;
 246 }
 247
 248 /* For the hash of exported symbols */
 249 static void hash_add_symbol(struct symbol *sym)
 250 {
 251         hash_add(symbol_hashtable, &sym->hnode, tdb_hash(sym->name));
 252 }
 253
 254 static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
 255 {
 256         struct symbol *sym;
 257
 258         sym = alloc_symbol(name);
 259         sym->weak = weak;
 260
 261         list_add_tail(&sym->list, &mod->unresolved_symbols);
 262 }
 263
 264 static struct symbol *sym_find_with_module(const char *name, struct module *mod)
 265 {
 266         struct symbol *s;
 267
 268         /* For our purposes, .foo matches foo.  PPC64 needs this. */
 269         if (name[0] == '.')
 270                 name++;
 271
 272         hash_for_each_possible(symbol_hashtable, s, hnode, tdb_hash(name)) {
 273                 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
 274                         return s;
 275         }
 276         return NULL;
 277 }
 278
 279 static struct symbol *find_symbol(const char *name)
 280 {
 281         return sym_find_with_module(name, NULL);
 282 }
 283
 284 struct namespace_list {
 285         struct list_head list;
 286         char namespace[];
 287 };
 288
 289 static bool contains_namespace(struct list_head *head, const char *namespace)
 290 {
 291         struct namespace_list *list;
 292
 293         /*
 294          * The default namespace is null string "", which is always implicitly
 295          * contained.
 296          */
 297         if (!namespace[0])
 298                 return true;
 299
 300         list_for_each_entry(list, head, list) {
 301                 if (!strcmp(list->namespace, namespace))
 302                         return true;
 303         }
 304
 305         return false;
 306 }
 307
 308 static void add_namespace(struct list_head *head, const char *namespace)
 309 {
 310         struct namespace_list *ns_entry;
 311
 312         if (!contains_namespace(head, namespace)) {
 313                 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) +
 314                                          strlen(namespace) + 1));
 315                 strcpy(ns_entry->namespace, namespace);
 316                 list_add_tail(&ns_entry->list, head);
 317         }
 318 }
 319
 320 static void *sym_get_data_by_offset(const struct elf_info *info,
 321                                     unsigned int secindex, unsigned long offset)
 322 {
 323         Elf_Shdr *sechdr = &info->sechdrs[secindex];
 324
 325         return (void *)info->hdr + sechdr->sh_offset + offset;
 326 }
 327
 328 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
 329 {
 330         return sym_get_data_by_offset(info, get_secindex(info, sym),
 331                                       sym->st_value);
 332 }
 333
 334 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
 335 {
 336         return sym_get_data_by_offset(info, info->secindex_strings,
 337                                       sechdr->sh_name);
 338 }
 339
 340 static const char *sec_name(const struct elf_info *info, unsigned int secindex)
 341 {
 342         /*
 343          * If sym->st_shndx is a special section index, there is no
 344          * corresponding section header.
 345          * Return "" if the index is out of range of info->sechdrs[] array.
 346          */
 347         if (secindex >= info->num_sections)
 348                 return "";
 349
 350         return sech_name(info, &info->sechdrs[secindex]);
 351 }
 352
 353 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
 354
 355 static struct symbol *sym_add_exported(const char *name, struct module *mod,
 356                                        bool gpl_only, const char *namespace)
 357 {
 358         struct symbol *s = find_symbol(name);
 359
 360         if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
 361                 error("%s: '%s' exported twice. Previous export was in %s%s\n",
 362                       mod->name, name, s->module->name,
 363                       s->module->is_vmlinux ? "" : ".ko");
 364         }
 365
 366         s = alloc_symbol(name);
 367         s->module = mod;
 368         s->is_gpl_only = gpl_only;
 369         s->namespace = NOFAIL(strdup(namespace));
 370         list_add_tail(&s->list, &mod->exported_symbols);
 371         hash_add_symbol(s);
 372
 373         return s;
 374 }
 375
 376 static void sym_set_crc(struct symbol *sym, unsigned int crc)
 377 {
 378         sym->crc = crc;
 379         sym->crc_valid = true;
 380 }
 381
 382 static void *grab_file(const char *filename, size_t *size)
 383 {
 384         struct stat st;
 385         void *map = MAP_FAILED;
 386         int fd;
 387
 388         fd = open(filename, O_RDONLY);
 389         if (fd < 0)
 390                 return NULL;
 391         if (fstat(fd, &st))
 392                 goto failed;
 393
 394         *size = st.st_size;
 395         map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 396
 397 failed:
 398         close(fd);
 399         if (map == MAP_FAILED)
 400                 return NULL;
 401         return map;
 402 }
 403
 404 static void release_file(void *file, size_t size)
 405 {
 406         munmap(file, size);
 407 }
 408
 409 static int parse_elf(struct elf_info *info, const char *filename)
 410 {
 411         unsigned int i;
 412         Elf_Ehdr *hdr;
 413         Elf_Shdr *sechdrs;
 414         Elf_Sym  *sym;
 415         const char *secstrings;
 416         unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
 417
 418         hdr = grab_file(filename, &info->size);
 419         if (!hdr) {
 420                 if (ignore_missing_files) {
 421                         fprintf(stderr, "%s: %s (ignored)\n", filename,
 422                                 strerror(errno));
 423                         return 0;
 424                 }
 425                 perror(filename);
 426                 exit(1);
 427         }
 428         info->hdr = hdr;
 429         if (info->size < sizeof(*hdr)) {
 430                 /* file too small, assume this is an empty .o file */
 431                 return 0;
 432         }
 433         /* Is this a valid ELF file? */
 434         if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 435             (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 436             (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 437             (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 438                 /* Not an ELF file - silently ignore it */
 439                 return 0;
 440         }
 441         /* Fix endianness in ELF header */
 442         hdr->e_type      = TO_NATIVE(hdr->e_type);
 443         hdr->e_machine   = TO_NATIVE(hdr->e_machine);
 444         hdr->e_version   = TO_NATIVE(hdr->e_version);
 445         hdr->e_entry     = TO_NATIVE(hdr->e_entry);
 446         hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
 447         hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
 448         hdr->e_flags     = TO_NATIVE(hdr->e_flags);
 449         hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
 450         hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
 451         hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
 452         hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
 453         hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
 454         hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
 455         sechdrs = (void *)hdr + hdr->e_shoff;
 456         info->sechdrs = sechdrs;
 457
 458         /* modpost only works for relocatable objects */
 459         if (hdr->e_type != ET_REL)
 460                 fatal("%s: not relocatable object.", filename);
 461
 462         /* Check if file offset is correct */
 463         if (hdr->e_shoff > info->size)
 464                 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
 465                       (unsigned long)hdr->e_shoff, filename, info->size);
 466
 467         if (hdr->e_shnum == SHN_UNDEF) {
 468                 /*
 469                  * There are more than 64k sections,
 470                  * read count from .sh_size.
 471                  */
 472                 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
 473         }
 474         else {
 475                 info->num_sections = hdr->e_shnum;
 476         }
 477         if (hdr->e_shstrndx == SHN_XINDEX) {
 478                 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
 479         }
 480         else {
 481                 info->secindex_strings = hdr->e_shstrndx;
 482         }
 483
 484         /* Fix endianness in section headers */
 485         for (i = 0; i < info->num_sections; i++) {
 486                 sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
 487                 sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
 488                 sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
 489                 sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
 490                 sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
 491                 sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
 492                 sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
 493                 sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
 494                 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
 495                 sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
 496         }
 497         /* Find symbol table. */
 498         secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
 499         for (i = 1; i < info->num_sections; i++) {
 500                 const char *secname;
 501                 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
 502
 503                 if (!nobits && sechdrs[i].sh_offset > info->size)
 504                         fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
 505                               filename, (unsigned long)sechdrs[i].sh_offset,
 506                               sizeof(*hdr));
 507
 508                 secname = secstrings + sechdrs[i].sh_name;
 509                 if (strcmp(secname, ".modinfo") == 0) {
 510                         if (nobits)
 511                                 fatal("%s has NOBITS .modinfo\n", filename);
 512                         info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 513                         info->modinfo_len = sechdrs[i].sh_size;
 514                 } else if (!strcmp(secname, ".export_symbol")) {
 515                         info->export_symbol_secndx = i;
 516                 }
 517
 518                 if (sechdrs[i].sh_type == SHT_SYMTAB) {
 519                         unsigned int sh_link_idx;
 520                         symtab_idx = i;
 521                         info->symtab_start = (void *)hdr +
 522                             sechdrs[i].sh_offset;
 523                         info->symtab_stop  = (void *)hdr +
 524                             sechdrs[i].sh_offset + sechdrs[i].sh_size;
 525                         sh_link_idx = sechdrs[i].sh_link;
 526                         info->strtab       = (void *)hdr +
 527                             sechdrs[sh_link_idx].sh_offset;
 528                 }
 529
 530                 /* 32bit section no. table? ("more than 64k sections") */
 531                 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
 532                         symtab_shndx_idx = i;
 533                         info->symtab_shndx_start = (void *)hdr +
 534                             sechdrs[i].sh_offset;
 535                         info->symtab_shndx_stop  = (void *)hdr +
 536                             sechdrs[i].sh_offset + sechdrs[i].sh_size;
 537                 }
 538         }
 539         if (!info->symtab_start)
 540                 fatal("%s has no symtab?\n", filename);
 541
 542         /* Fix endianness in symbols */
 543         for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 544                 sym->st_shndx = TO_NATIVE(sym->st_shndx);
 545                 sym->st_name  = TO_NATIVE(sym->st_name);
 546                 sym->st_value = TO_NATIVE(sym->st_value);
 547                 sym->st_size  = TO_NATIVE(sym->st_size);
 548         }
 549
 550         if (symtab_shndx_idx != ~0U) {
 551                 Elf32_Word *p;
 552                 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
 553                         fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
 554                               filename, sechdrs[symtab_shndx_idx].sh_link,
 555                               symtab_idx);
 556                 /* Fix endianness */
 557                 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
 558                      p++)
 559                         *p = TO_NATIVE(*p);
 560         }
 561
 562         symsearch_init(info);
 563
 564         return 1;
 565 }
 566
 567 static void parse_elf_finish(struct elf_info *info)
 568 {
 569         symsearch_finish(info);
 570         release_file(info->hdr, info->size);
 571 }
 572
 573 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 574 {
 575         /* ignore __this_module, it will be resolved shortly */
 576         if (strcmp(symname, "__this_module") == 0)
 577                 return 1;
 578         /* ignore global offset table */
 579         if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 580                 return 1;
 581         if (info->hdr->e_machine == EM_PPC)
 582                 /* Special register function linked on all modules during final link of .ko */
 583                 if (strstarts(symname, "_restgpr_") ||
 584                     strstarts(symname, "_savegpr_") ||
 585                     strstarts(symname, "_rest32gpr_") ||
 586                     strstarts(symname, "_save32gpr_") ||
 587                     strstarts(symname, "_restvr_") ||
 588                     strstarts(symname, "_savevr_"))
 589                         return 1;
 590         if (info->hdr->e_machine == EM_PPC64)
 591                 /* Special register function linked on all modules during final link of .ko */
 592                 if (strstarts(symname, "_restgpr0_") ||
 593                     strstarts(symname, "_savegpr0_") ||
 594                     strstarts(symname, "_restvr_") ||
 595                     strstarts(symname, "_savevr_") ||
 596                     strcmp(symname, ".TOC.") == 0)
 597                         return 1;
 598         /* Do not ignore this symbol */
 599         return 0;
 600 }
 601
 602 static void handle_symbol(struct module *mod, struct elf_info *info,
 603                           const Elf_Sym *sym, const char *symname)
 604 {
 605         switch (sym->st_shndx) {
 606         case SHN_COMMON:
 607                 if (strstarts(symname, "__gnu_lto_")) {
 608                         /* Should warn here, but modpost runs before the linker */
 609                 } else
 610                         warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 611                 break;
 612         case SHN_UNDEF:
 613                 /* undefined symbol */
 614                 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 615                     ELF_ST_BIND(sym->st_info) != STB_WEAK)
 616                         break;
 617                 if (ignore_undef_symbol(info, symname))
 618                         break;
 619                 if (info->hdr->e_machine == EM_SPARC ||
 620                     info->hdr->e_machine == EM_SPARCV9) {
 621                         /* Ignore register directives. */
 622                         if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 623                                 break;
 624                         if (symname[0] == '.') {
 625                                 char *munged = NOFAIL(strdup(symname));
 626                                 munged[0] = '_';
 627                                 munged[1] = toupper(munged[1]);
 628                                 symname = munged;
 629                         }
 630                 }
 631
 632                 sym_add_unresolved(symname, mod,
 633                                    ELF_ST_BIND(sym->st_info) == STB_WEAK);
 634                 break;
 635         default:
 636                 if (strcmp(symname, "init_module") == 0)
 637                         mod->has_init = true;
 638                 if (strcmp(symname, "cleanup_module") == 0)
 639                         mod->has_cleanup = true;
 640                 break;
 641         }
 642 }
 643
 644 /**
 645  * Parse tag=value strings from .modinfo section
 646  **/
 647 static char *next_string(char *string, unsigned long *secsize)
 648 {
 649         /* Skip non-zero chars */
 650         while (string[0]) {
 651                 string++;
 652                 if ((*secsize)-- <= 1)
 653                         return NULL;
 654         }
 655
 656         /* Skip any zero padding. */
 657         while (!string[0]) {
 658                 string++;
 659                 if ((*secsize)-- <= 1)
 660                         return NULL;
 661         }
 662         return string;
 663 }
 664
 665 static char *get_next_modinfo(struct elf_info *info, const char *tag,
 666                               char *prev)
 667 {
 668         char *p;
 669         unsigned int taglen = strlen(tag);
 670         char *modinfo = info->modinfo;
 671         unsigned long size = info->modinfo_len;
 672
 673         if (prev) {
 674                 size -= prev - modinfo;
 675                 modinfo = next_string(prev, &size);
 676         }
 677
 678         for (p = modinfo; p; p = next_string(p, &size)) {
 679                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 680                         return p + taglen + 1;
 681         }
 682         return NULL;
 683 }
 684
 685 static char *get_modinfo(struct elf_info *info, const char *tag)
 686
 687 {
 688         return get_next_modinfo(info, tag, NULL);
 689 }
 690
 691 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
 692 {
 693         if (sym)
 694                 return elf->strtab + sym->st_name;
 695         else
 696                 return "(unknown)";
 697 }
 698
 699 /*
 700  * Check whether the 'string' argument matches one of the 'patterns',
 701  * an array of shell wildcard patterns (glob).
 702  *
 703  * Return true is there is a match.
 704  */
 705 static bool match(const char *string, const char *const patterns[])
 706 {
 707         const char *pattern;
 708
 709         while ((pattern = *patterns++)) {
 710                 if (!fnmatch(pattern, string, 0))
 711                         return true;
 712         }
 713
 714         return false;
 715 }
 716
 717 /* useful to pass patterns to match() directly */
 718 #define PATTERNS(...) \
 719         ({ \
 720                 static const char *const patterns[] = {__VA_ARGS__, NULL}; \
 721                 patterns; \
 722         })
 723
 724 /* sections that we do not want to do full section mismatch check on */
 725 static const char *const section_white_list[] =
 726 {
 727         ".comment*",
 728         ".debug*",
 729         ".zdebug*",             /* Compressed debug sections. */
 730         ".GCC.command.line",    /* record-gcc-switches */
 731         ".mdebug*",        /* alpha, score, mips etc. */
 732         ".pdr",            /* alpha, score, mips etc. */
 733         ".stab*",
 734         ".note*",
 735         ".got*",
 736         ".toc*",
 737         ".xt.prop",                              /* xtensa */
 738         ".xt.lit",         /* xtensa */
 739         ".arcextmap*",                  /* arc */
 740         ".gnu.linkonce.arcext*",        /* arc : modules */
 741         ".cmem*",                       /* EZchip */
 742         ".fmt_slot*",                   /* EZchip */
 743         ".gnu.lto*",
 744         ".discard.*",
 745         ".llvm.call-graph-profile",     /* call graph */
 746         NULL
 747 };
 748
 749 /*
 750  * This is used to find sections missing the SHF_ALLOC flag.
 751  * The cause of this is often a section specified in assembler
 752  * without "ax" / "aw".
 753  */
 754 static void check_section(const char *modname, struct elf_info *elf,
 755                           Elf_Shdr *sechdr)
 756 {
 757         const char *sec = sech_name(elf, sechdr);
 758
 759         if (sechdr->sh_type == SHT_PROGBITS &&
 760             !(sechdr->sh_flags & SHF_ALLOC) &&
 761             !match(sec, section_white_list)) {
 762                 warn("%s (%s): unexpected non-allocatable section.\n"
 763                      "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
 764                      "Note that for example <linux/init.h> contains\n"
 765                      "section definitions for use in .S files.\n\n",
 766                      modname, sec);
 767         }
 768 }
 769
 770
 771
 772 #define ALL_INIT_DATA_SECTIONS \
 773         ".init.setup", ".init.rodata", ".init.data"
 774
 775 #define ALL_PCI_INIT_SECTIONS   \
 776         ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
 777         ".pci_fixup_enable", ".pci_fixup_resume", \
 778         ".pci_fixup_resume_early", ".pci_fixup_suspend"
 779
 780 #define ALL_INIT_SECTIONS ".init.*"
 781 #define ALL_EXIT_SECTIONS ".exit.*"
 782
 783 #define DATA_SECTIONS ".data", ".data.rel"
 784 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
 785                 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \
 786                 ".ltext", ".ltext.*"
 787 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
 788                 ".fixup", ".entry.text", ".exception.text", \
 789                 ".coldtext", ".softirqentry.text"
 790
 791 #define ALL_TEXT_SECTIONS  ".init.text", ".exit.text", \
 792                 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
 793
 794 enum mismatch {
 795         TEXTDATA_TO_ANY_INIT_EXIT,
 796         XXXINIT_TO_SOME_INIT,
 797         ANY_INIT_TO_ANY_EXIT,
 798         ANY_EXIT_TO_ANY_INIT,
 799         EXTABLE_TO_NON_TEXT,
 800 };
 801
 802 /**
 803  * Describe how to match sections on different criteria:
 804  *
 805  * @fromsec: Array of sections to be matched.
 806  *
 807  * @bad_tosec: Relocations applied to a section in @fromsec to a section in
 808  * this array is forbidden (black-list).  Can be empty.
 809  *
 810  * @good_tosec: Relocations applied to a section in @fromsec must be
 811  * targeting sections in this array (white-list).  Can be empty.
 812  *
 813  * @mismatch: Type of mismatch.
 814  */
 815 struct sectioncheck {
 816         const char *fromsec[20];
 817         const char *bad_tosec[20];
 818         const char *good_tosec[20];
 819         enum mismatch mismatch;
 820 };
 821
 822 static const struct sectioncheck sectioncheck[] = {
 823 /* Do not reference init/exit code/data from
 824  * normal code and data
 825  */
 826 {
 827         .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
 828         .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
 829         .mismatch = TEXTDATA_TO_ANY_INIT_EXIT,
 830 },
 831 /* Do not use exit code/data from init code */
 832 {
 833         .fromsec = { ALL_INIT_SECTIONS, NULL },
 834         .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
 835         .mismatch = ANY_INIT_TO_ANY_EXIT,
 836 },
 837 /* Do not use init code/data from exit code */
 838 {
 839         .fromsec = { ALL_EXIT_SECTIONS, NULL },
 840         .bad_tosec = { ALL_INIT_SECTIONS, NULL },
 841         .mismatch = ANY_EXIT_TO_ANY_INIT,
 842 },
 843 {
 844         .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
 845         .bad_tosec = { ALL_INIT_SECTIONS, NULL },
 846         .mismatch = ANY_INIT_TO_ANY_EXIT,
 847 },
 848 {
 849         .fromsec = { "__ex_table", NULL },
 850         /* If you're adding any new black-listed sections in here, consider
 851          * adding a special 'printer' for them in scripts/check_extable.
 852          */
 853         .bad_tosec = { ".altinstr_replacement", NULL },
 854         .good_tosec = {ALL_TEXT_SECTIONS , NULL},
 855         .mismatch = EXTABLE_TO_NON_TEXT,
 856 }
 857 };
 858
 859 static const struct sectioncheck *section_mismatch(
 860                 const char *fromsec, const char *tosec)
 861 {
 862         int i;
 863
 864         /*
 865          * The target section could be the SHT_NUL section when we're
 866          * handling relocations to un-resolved symbols, trying to match it
 867          * doesn't make much sense and causes build failures on parisc
 868          * architectures.
 869          */
 870         if (*tosec == '\0')
 871                 return NULL;
 872
 873         for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
 874                 const struct sectioncheck *check = &sectioncheck[i];
 875
 876                 if (match(fromsec, check->fromsec)) {
 877                         if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
 878                                 return check;
 879                         if (check->good_tosec[0] && !match(tosec, check->good_tosec))
 880                                 return check;
 881                 }
 882         }
 883         return NULL;
 884 }
 885
 886 /**
 887  * Whitelist to allow certain references to pass with no warning.
 888  *
 889  * Pattern 1:
 890  *   If a module parameter is declared __initdata and permissions=0
 891  *   then this is legal despite the warning generated.
 892  *   We cannot see value of permissions here, so just ignore
 893  *   this pattern.
 894  *   The pattern is identified by:
 895  *   tosec   = .init.data
 896  *   fromsec = .data*
 897  *   atsym   =__param*
 898  *
 899  * Pattern 1a:
 900  *   module_param_call() ops can refer to __init set function if permissions=0
 901  *   The pattern is identified by:
 902  *   tosec   = .init.text
 903  *   fromsec = .data*
 904  *   atsym   = __param_ops_*
 905  *
 906  * Pattern 3:
 907  *   Whitelist all references from .head.text to any init section
 908  *
 909  * Pattern 4:
 910  *   Some symbols belong to init section but still it is ok to reference
 911  *   these from non-init sections as these symbols don't have any memory
 912  *   allocated for them and symbol address and value are same. So even
 913  *   if init section is freed, its ok to reference those symbols.
 914  *   For ex. symbols marking the init section boundaries.
 915  *   This pattern is identified by
 916  *   refsymname = __init_begin, _sinittext, _einittext
 917  *
 918  * Pattern 5:
 919  *   GCC may optimize static inlines when fed constant arg(s) resulting
 920  *   in functions like cpumask_empty() -- generating an associated symbol
 921  *   cpumask_empty.constprop.3 that appears in the audit.  If the const that
 922  *   is passed in comes from __init, like say nmi_ipi_mask, we get a
 923  *   meaningless section warning.  May need to add isra symbols too...
 924  *   This pattern is identified by
 925  *   tosec   = init section
 926  *   fromsec = text section
 927  *   refsymname = *.constprop.*
 928  *
 929  **/
 930 static int secref_whitelist(const char *fromsec, const char *fromsym,
 931                             const char *tosec, const char *tosym)
 932 {
 933         /* Check for pattern 1 */
 934         if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
 935             match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 936             strstarts(fromsym, "__param"))
 937                 return 0;
 938
 939         /* Check for pattern 1a */
 940         if (strcmp(tosec, ".init.text") == 0 &&
 941             match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 942             strstarts(fromsym, "__param_ops_"))
 943                 return 0;
 944
 945         /* symbols in data sections that may refer to any init/exit sections */
 946         if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 947             match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
 948             match(fromsym, PATTERNS("*_ops", "*_probe", "*_console")))
 949                 return 0;
 950
 951         /* Check for pattern 3 */
 952         if (strstarts(fromsec, ".head.text") &&
 953             match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
 954                 return 0;
 955
 956         /* Check for pattern 4 */
 957         if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
 958                 return 0;
 959
 960         /* Check for pattern 5 */
 961         if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
 962             match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
 963             match(fromsym, PATTERNS("*.constprop.*")))
 964                 return 0;
 965
 966         return 1;
 967 }
 968
 969 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
 970                              unsigned int secndx)
 971 {
 972         return symsearch_find_nearest(elf, addr, secndx, false, ~0);
 973 }
 974
 975 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
 976 {
 977         Elf_Sym *new_sym;
 978
 979         /* If the supplied symbol has a valid name, return it */
 980         if (is_valid_name(elf, sym))
 981                 return sym;
 982
 983         /*
 984          * Strive to find a better symbol name, but the resulting name may not
 985          * match the symbol referenced in the original code.
 986          */
 987         new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym),
 988                                          true, 20);
 989         return new_sym ? new_sym : sym;
 990 }
 991
 992 static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
 993 {
 994         if (secndx >= elf->num_sections)
 995                 return false;
 996
 997         return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
 998 }
 999
1000 static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1001                                      const struct sectioncheck* const mismatch,
1002                                      Elf_Sym *tsym,
1003                                      unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
1004                                      const char *tosec, Elf_Addr taddr)
1005 {
1006         Elf_Sym *from;
1007         const char *tosym;
1008         const char *fromsym;
1009
1010         from = find_fromsym(elf, faddr, fsecndx);
1011         fromsym = sym_name(elf, from);
1012
1013         tsym = find_tosym(elf, taddr, tsym);
1014         tosym = sym_name(elf, tsym);
1015
1016         /* check whitelist - we may ignore it */
1017         if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1018                 return;
1019
1020         sec_mismatch_count++;
1021
1022         warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n",
1023              modname, fromsym,
1024              (unsigned int)(faddr - (from ? from->st_value : 0)),
1025              fromsec, tosym, tosec);
1026
1027         if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1028                 if (match(tosec, mismatch->bad_tosec))
1029                         fatal("The relocation at %s+0x%lx references\n"
1030                               "section \"%s\" which is black-listed.\n"
1031                               "Something is seriously wrong and should be fixed.\n"
1032                               "You might get more information about where this is\n"
1033                               "coming from by using scripts/check_extable.sh %s\n",
1034                               fromsec, (long)faddr, tosec, modname);
1035                 else if (is_executable_section(elf, get_secindex(elf, tsym)))
1036                         warn("The relocation at %s+0x%lx references\n"
1037                              "section \"%s\" which is not in the list of\n"
1038                              "authorized sections.  If you're adding a new section\n"
1039                              "and/or if this reference is valid, add \"%s\" to the\n"
1040                              "list of authorized sections to jump to on fault.\n"
1041                              "This can be achieved by adding \"%s\" to\n"
1042                              "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1043                              fromsec, (long)faddr, tosec, tosec, tosec);
1044                 else
1045                         error("%s+0x%lx references non-executable section '%s'\n",
1046                               fromsec, (long)faddr, tosec);
1047         }
1048 }
1049
1050 static void check_export_symbol(struct module *mod, struct elf_info *elf,
1051                                 Elf_Addr faddr, const char *secname,
1052                                 Elf_Sym *sym)
1053 {
1054         static const char *prefix = "__export_symbol_";
1055         const char *label_name, *name, *data;
1056         Elf_Sym *label;
1057         struct symbol *s;
1058         bool is_gpl;
1059
1060         label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1061         label_name = sym_name(elf, label);
1062
1063         if (!strstarts(label_name, prefix)) {
1064                 error("%s: .export_symbol section contains strange symbol '%s'\n",
1065                       mod->name, label_name);
1066                 return;
1067         }
1068
1069         if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1070             ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1071                 error("%s: local symbol '%s' was exported\n", mod->name,
1072                       label_name + strlen(prefix));
1073                 return;
1074         }
1075
1076         name = sym_name(elf, sym);
1077         if (strcmp(label_name + strlen(prefix), name)) {
1078                 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1079                       mod->name, name);
1080                 return;
1081         }
1082
1083         data = sym_get_data(elf, label);        /* license */
1084         if (!strcmp(data, "GPL")) {
1085                 is_gpl = true;
1086         } else if (!strcmp(data, "")) {
1087                 is_gpl = false;
1088         } else {
1089                 error("%s: unknown license '%s' was specified for '%s'\n",
1090                       mod->name, data, name);
1091                 return;
1092         }
1093
1094         data += strlen(data) + 1;       /* namespace */
1095         s = sym_add_exported(name, mod, is_gpl, data);
1096
1097         /*
1098          * We need to be aware whether we are exporting a function or
1099          * a data on some architectures.
1100          */
1101         s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1102
1103         /*
1104          * For parisc64, symbols prefixed $$ from the library have the symbol type
1105          * STT_LOPROC. They should be handled as functions too.
1106          */
1107         if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1108             elf->hdr->e_machine == EM_PARISC &&
1109             ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1110                 s->is_func = true;
1111
1112         if (match(secname, PATTERNS(ALL_INIT_SECTIONS)))
1113                 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1114                      mod->name, name);
1115         else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS)))
1116                 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1117                      mod->name, name);
1118 }
1119
1120 static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1121                                    Elf_Sym *sym,
1122                                    unsigned int fsecndx, const char *fromsec,
1123                                    Elf_Addr faddr, Elf_Addr taddr)
1124 {
1125         const char *tosec = sec_name(elf, get_secindex(elf, sym));
1126         const struct sectioncheck *mismatch;
1127
1128         if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1129                 check_export_symbol(mod, elf, faddr, tosec, sym);
1130                 return;
1131         }
1132
1133         mismatch = section_mismatch(fromsec, tosec);
1134         if (!mismatch)
1135                 return;
1136
1137         default_mismatch_handler(mod->name, elf, mismatch, sym,
1138                                  fsecndx, fromsec, faddr,
1139                                  tosec, taddr);
1140 }
1141
1142 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1143 {
1144         switch (r_type) {
1145         case R_386_32:
1146                 return TO_NATIVE(*location);
1147         case R_386_PC32:
1148                 return TO_NATIVE(*location) + 4;
1149         }
1150
1151         return (Elf_Addr)(-1);
1152 }
1153
1154 static int32_t sign_extend32(int32_t value, int index)
1155 {
1156         uint8_t shift = 31 - index;
1157
1158         return (int32_t)(value << shift) >> shift;
1159 }
1160
1161 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1162 {
1163         uint32_t inst, upper, lower, sign, j1, j2;
1164         int32_t offset;
1165
1166         switch (r_type) {
1167         case R_ARM_ABS32:
1168         case R_ARM_REL32:
1169                 inst = TO_NATIVE(*(uint32_t *)loc);
1170                 return inst + sym->st_value;
1171         case R_ARM_MOVW_ABS_NC:
1172         case R_ARM_MOVT_ABS:
1173                 inst = TO_NATIVE(*(uint32_t *)loc);
1174                 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1175                                        15);
1176                 return offset + sym->st_value;
1177         case R_ARM_PC24:
1178         case R_ARM_CALL:
1179         case R_ARM_JUMP24:
1180                 inst = TO_NATIVE(*(uint32_t *)loc);
1181                 offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1182                 return offset + sym->st_value + 8;
1183         case R_ARM_THM_MOVW_ABS_NC:
1184         case R_ARM_THM_MOVT_ABS:
1185                 upper = TO_NATIVE(*(uint16_t *)loc);
1186                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1187                 offset = sign_extend32(((upper & 0x000f) << 12) |
1188                                        ((upper & 0x0400) << 1) |
1189                                        ((lower & 0x7000) >> 4) |
1190                                        (lower & 0x00ff),
1191                                        15);
1192                 return offset + sym->st_value;
1193         case R_ARM_THM_JUMP19:
1194                 /*
1195                  * Encoding T3:
1196                  * S     = upper[10]
1197                  * imm6  = upper[5:0]
1198                  * J1    = lower[13]
1199                  * J2    = lower[11]
1200                  * imm11 = lower[10:0]
1201                  * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1202                  */
1203                 upper = TO_NATIVE(*(uint16_t *)loc);
1204                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1205
1206                 sign = (upper >> 10) & 1;
1207                 j1 = (lower >> 13) & 1;
1208                 j2 = (lower >> 11) & 1;
1209                 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1210                                        ((upper & 0x03f) << 12) |
1211                                        ((lower & 0x07ff) << 1),
1212                                        20);
1213                 return offset + sym->st_value + 4;
1214         case R_ARM_THM_PC22:
1215         case R_ARM_THM_JUMP24:
1216                 /*
1217                  * Encoding T4:
1218                  * S     = upper[10]
1219                  * imm10 = upper[9:0]
1220                  * J1    = lower[13]
1221                  * J2    = lower[11]
1222                  * imm11 = lower[10:0]
1223                  * I1    = NOT(J1 XOR S)
1224                  * I2    = NOT(J2 XOR S)
1225                  * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1226                  */
1227                 upper = TO_NATIVE(*(uint16_t *)loc);
1228                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1229
1230                 sign = (upper >> 10) & 1;
1231                 j1 = (lower >> 13) & 1;
1232                 j2 = (lower >> 11) & 1;
1233                 offset = sign_extend32((sign << 24) |
1234                                        ((~(j1 ^ sign) & 1) << 23) |
1235                                        ((~(j2 ^ sign) & 1) << 22) |
1236                                        ((upper & 0x03ff) << 12) |
1237                                        ((lower & 0x07ff) << 1),
1238                                        24);
1239                 return offset + sym->st_value + 4;
1240         }
1241
1242         return (Elf_Addr)(-1);
1243 }
1244
1245 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1246 {
1247         uint32_t inst;
1248
1249         inst = TO_NATIVE(*location);
1250         switch (r_type) {
1251         case R_MIPS_LO16:
1252                 return inst & 0xffff;
1253         case R_MIPS_26:
1254                 return (inst & 0x03ffffff) << 2;
1255         case R_MIPS_32:
1256                 return inst;
1257         }
1258         return (Elf_Addr)(-1);
1259 }
1260
1261 #ifndef EM_RISCV
1262 #define EM_RISCV                243
1263 #endif
1264
1265 #ifndef R_RISCV_SUB32
1266 #define R_RISCV_SUB32           39
1267 #endif
1268
1269 #ifndef EM_LOONGARCH
1270 #define EM_LOONGARCH            258
1271 #endif
1272
1273 #ifndef R_LARCH_SUB32
1274 #define R_LARCH_SUB32           55
1275 #endif
1276
1277 #ifndef R_LARCH_RELAX
1278 #define R_LARCH_RELAX           100
1279 #endif
1280
1281 #ifndef R_LARCH_ALIGN
1282 #define R_LARCH_ALIGN           102
1283 #endif
1284
1285 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1286                                  unsigned int *r_type, unsigned int *r_sym)
1287 {
1288         typedef struct {
1289                 Elf64_Word    r_sym;    /* Symbol index */
1290                 unsigned char r_ssym;   /* Special symbol for 2nd relocation */
1291                 unsigned char r_type3;  /* 3rd relocation type */
1292                 unsigned char r_type2;  /* 2nd relocation type */
1293                 unsigned char r_type;   /* 1st relocation type */
1294         } Elf64_Mips_R_Info;
1295
1296         bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1297
1298         if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1299                 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1300
1301                 *r_type = mips64_r_info->r_type;
1302                 *r_sym = TO_NATIVE(mips64_r_info->r_sym);
1303                 return;
1304         }
1305
1306         if (is_64bit)
1307                 r_info = TO_NATIVE((Elf64_Xword)r_info);
1308         else
1309                 r_info = TO_NATIVE((Elf32_Word)r_info);
1310
1311         *r_type = ELF_R_TYPE(r_info);
1312         *r_sym = ELF_R_SYM(r_info);
1313 }
1314
1315 static void section_rela(struct module *mod, struct elf_info *elf,
1316                          unsigned int fsecndx, const char *fromsec,
1317                          const Elf_Rela *start, const Elf_Rela *stop)
1318 {
1319         const Elf_Rela *rela;
1320
1321         for (rela = start; rela < stop; rela++) {
1322                 Elf_Sym *tsym;
1323                 Elf_Addr taddr, r_offset;
1324                 unsigned int r_type, r_sym;
1325
1326                 r_offset = TO_NATIVE(rela->r_offset);
1327                 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1328
1329                 tsym = elf->symtab_start + r_sym;
1330                 taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1331
1332                 switch (elf->hdr->e_machine) {
1333                 case EM_RISCV:
1334                         if (!strcmp("__ex_table", fromsec) &&
1335                             r_type == R_RISCV_SUB32)
1336                                 continue;
1337                         break;
1338                 case EM_LOONGARCH:
1339                         switch (r_type) {
1340                         case R_LARCH_SUB32:
1341                                 if (!strcmp("__ex_table", fromsec))
1342                                         continue;
1343                                 break;
1344                         case R_LARCH_RELAX:
1345                         case R_LARCH_ALIGN:
1346                                 /* These relocs do not refer to symbols */
1347                                 continue;
1348                         }
1349                         break;
1350                 }
1351
1352                 check_section_mismatch(mod, elf, tsym,
1353                                        fsecndx, fromsec, r_offset, taddr);
1354         }
1355 }
1356
1357 static void section_rel(struct module *mod, struct elf_info *elf,
1358                         unsigned int fsecndx, const char *fromsec,
1359                         const Elf_Rel *start, const Elf_Rel *stop)
1360 {
1361         const Elf_Rel *rel;
1362
1363         for (rel = start; rel < stop; rel++) {
1364                 Elf_Sym *tsym;
1365                 Elf_Addr taddr, r_offset;
1366                 unsigned int r_type, r_sym;
1367                 void *loc;
1368
1369                 r_offset = TO_NATIVE(rel->r_offset);
1370                 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1371
1372                 loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1373                 tsym = elf->symtab_start + r_sym;
1374
1375                 switch (elf->hdr->e_machine) {
1376                 case EM_386:
1377                         taddr = addend_386_rel(loc, r_type);
1378                         break;
1379                 case EM_ARM:
1380                         taddr = addend_arm_rel(loc, tsym, r_type);
1381                         break;
1382                 case EM_MIPS:
1383                         taddr = addend_mips_rel(loc, r_type);
1384                         break;
1385                 default:
1386                         fatal("Please add code to calculate addend for this architecture\n");
1387                 }
1388
1389                 check_section_mismatch(mod, elf, tsym,
1390                                        fsecndx, fromsec, r_offset, taddr);
1391         }
1392 }
1393
1394 /**
1395  * A module includes a number of sections that are discarded
1396  * either when loaded or when used as built-in.
1397  * For loaded modules all functions marked __init and all data
1398  * marked __initdata will be discarded when the module has been initialized.
1399  * Likewise for modules used built-in the sections marked __exit
1400  * are discarded because __exit marked function are supposed to be called
1401  * only when a module is unloaded which never happens for built-in modules.
1402  * The check_sec_ref() function traverses all relocation records
1403  * to find all references to a section that reference a section that will
1404  * be discarded and warns about it.
1405  **/
1406 static void check_sec_ref(struct module *mod, struct elf_info *elf)
1407 {
1408         int i;
1409
1410         /* Walk through all sections */
1411         for (i = 0; i < elf->num_sections; i++) {
1412                 Elf_Shdr *sechdr = &elf->sechdrs[i];
1413
1414                 check_section(mod->name, elf, sechdr);
1415                 /* We want to process only relocation sections and not .init */
1416                 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) {
1417                         /* section to which the relocation applies */
1418                         unsigned int secndx = sechdr->sh_info;
1419                         const char *secname = sec_name(elf, secndx);
1420                         const void *start, *stop;
1421
1422                         /* If the section is known good, skip it */
1423                         if (match(secname, section_white_list))
1424                                 continue;
1425
1426                         start = sym_get_data_by_offset(elf, i, 0);
1427                         stop = start + sechdr->sh_size;
1428
1429                         if (sechdr->sh_type == SHT_RELA)
1430                                 section_rela(mod, elf, secndx, secname,
1431                                              start, stop);
1432                         else
1433                                 section_rel(mod, elf, secndx, secname,
1434                                             start, stop);
1435                 }
1436         }
1437 }
1438
1439 static char *remove_dot(char *s)
1440 {
1441         size_t n = strcspn(s, ".");
1442
1443         if (n && s[n]) {
1444                 size_t m = strspn(s + n + 1, "0123456789");
1445                 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1446                         s[n] = 0;
1447         }
1448         return s;
1449 }
1450
1451 /*
1452  * The CRCs are recorded in .*.cmd files in the form of:
1453  * #SYMVER <name> <crc>
1454  */
1455 static void extract_crcs_for_object(const char *object, struct module *mod)
1456 {
1457         char cmd_file[PATH_MAX];
1458         char *buf, *p;
1459         const char *base;
1460         int dirlen, ret;
1461
1462         base = strrchr(object, '/');
1463         if (base) {
1464                 base++;
1465                 dirlen = base - object;
1466         } else {
1467                 dirlen = 0;
1468                 base = object;
1469         }
1470
1471         ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1472                        dirlen, object, base);
1473         if (ret >= sizeof(cmd_file)) {
1474                 error("%s: too long path was truncated\n", cmd_file);
1475                 return;
1476         }
1477
1478         buf = read_text_file(cmd_file);
1479         p = buf;
1480
1481         while ((p = strstr(p, "\n#SYMVER "))) {
1482                 char *name;
1483                 size_t namelen;
1484                 unsigned int crc;
1485                 struct symbol *sym;
1486
1487                 name = p + strlen("\n#SYMVER ");
1488
1489                 p = strchr(name, ' ');
1490                 if (!p)
1491                         break;
1492
1493                 namelen = p - name;
1494                 p++;
1495
1496                 if (!isdigit(*p))
1497                         continue;       /* skip this line */
1498
1499                 crc = strtoul(p, &p, 0);
1500                 if (*p != '\n')
1501                         continue;       /* skip this line */
1502
1503                 name[namelen] = '\0';
1504
1505                 /*
1506                  * sym_find_with_module() may return NULL here.
1507                  * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1508                  * Since commit e1327a127703, genksyms calculates CRCs of all
1509                  * symbols, including trimmed ones. Ignore orphan CRCs.
1510                  */
1511                 sym = sym_find_with_module(name, mod);
1512                 if (sym)
1513                         sym_set_crc(sym, crc);
1514         }
1515
1516         free(buf);
1517 }
1518
1519 /*
1520  * The symbol versions (CRC) are recorded in the .*.cmd files.
1521  * Parse them to retrieve CRCs for the current module.
1522  */
1523 static void mod_set_crcs(struct module *mod)
1524 {
1525         char objlist[PATH_MAX];
1526         char *buf, *p, *obj;
1527         int ret;
1528
1529         if (mod->is_vmlinux) {
1530                 strcpy(objlist, ".vmlinux.objs");
1531         } else {
1532                 /* objects for a module are listed in the *.mod file. */
1533                 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1534                 if (ret >= sizeof(objlist)) {
1535                         error("%s: too long path was truncated\n", objlist);
1536                         return;
1537                 }
1538         }
1539
1540         buf = read_text_file(objlist);
1541         p = buf;
1542
1543         while ((obj = strsep(&p, "\n")) && obj[0])
1544                 extract_crcs_for_object(obj, mod);
1545
1546         free(buf);
1547 }
1548
1549 static void read_symbols(const char *modname)
1550 {
1551         const char *symname;
1552         char *version;
1553         char *license;
1554         char *namespace;
1555         struct module *mod;
1556         struct elf_info info = { };
1557         Elf_Sym *sym;
1558
1559         if (!parse_elf(&info, modname))
1560                 return;
1561
1562         if (!strends(modname, ".o")) {
1563                 error("%s: filename must be suffixed with .o\n", modname);
1564                 return;
1565         }
1566
1567         /* strip trailing .o */
1568         mod = new_module(modname, strlen(modname) - strlen(".o"));
1569
1570         if (!mod->is_vmlinux) {
1571                 license = get_modinfo(&info, "license");
1572                 if (!license)
1573                         error("missing MODULE_LICENSE() in %s\n", modname);
1574                 while (license) {
1575                         if (!license_is_gpl_compatible(license)) {
1576                                 mod->is_gpl_compatible = false;
1577                                 break;
1578                         }
1579                         license = get_next_modinfo(&info, "license", license);
1580                 }
1581
1582                 namespace = get_modinfo(&info, "import_ns");
1583                 while (namespace) {
1584                         add_namespace(&mod->imported_namespaces, namespace);
1585                         namespace = get_next_modinfo(&info, "import_ns",
1586                                                      namespace);
1587                 }
1588
1589                 if (extra_warn && !get_modinfo(&info, "description"))
1590                         warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1591         }
1592
1593         for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1594                 symname = remove_dot(info.strtab + sym->st_name);
1595
1596                 handle_symbol(mod, &info, sym, symname);
1597                 handle_moddevtable(mod, &info, sym, symname);
1598         }
1599
1600         check_sec_ref(mod, &info);
1601
1602         if (!mod->is_vmlinux) {
1603                 version = get_modinfo(&info, "version");
1604                 if (version || all_versions)
1605                         get_src_version(mod->name, mod->srcversion,
1606                                         sizeof(mod->srcversion) - 1);
1607         }
1608
1609         parse_elf_finish(&info);
1610
1611         if (modversions) {
1612                 /*
1613                  * Our trick to get versioning for module struct etc. - it's
1614                  * never passed as an argument to an exported function, so
1615                  * the automatic versioning doesn't pick it up, but it's really
1616                  * important anyhow.
1617                  */
1618                 sym_add_unresolved("module_layout", mod, false);
1619
1620                 mod_set_crcs(mod);
1621         }
1622 }
1623
1624 static void read_symbols_from_files(const char *filename)
1625 {
1626         FILE *in = stdin;
1627         char fname[PATH_MAX];
1628
1629         in = fopen(filename, "r");
1630         if (!in)
1631                 fatal("Can't open filenames file %s: %m", filename);
1632
1633         while (fgets(fname, PATH_MAX, in) != NULL) {
1634                 if (strends(fname, "\n"))
1635                         fname[strlen(fname)-1] = '\0';
1636                 read_symbols(fname);
1637         }
1638
1639         fclose(in);
1640 }
1641
1642 #define SZ 500
1643
1644 /* We first write the generated file into memory using the
1645  * following helper, then compare to the file on disk and
1646  * only update the later if anything changed */
1647
1648 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1649                                                       const char *fmt, ...)
1650 {
1651         char tmp[SZ];
1652         int len;
1653         va_list ap;
1654
1655         va_start(ap, fmt);
1656         len = vsnprintf(tmp, SZ, fmt, ap);
1657         buf_write(buf, tmp, len);
1658         va_end(ap);
1659 }
1660
1661 void buf_write(struct buffer *buf, const char *s, int len)
1662 {
1663         if (buf->size - buf->pos < len) {
1664                 buf->size += len + SZ;
1665                 buf->p = NOFAIL(realloc(buf->p, buf->size));
1666         }
1667         strncpy(buf->p + buf->pos, s, len);
1668         buf->pos += len;
1669 }
1670
1671 static void check_exports(struct module *mod)
1672 {
1673         struct symbol *s, *exp;
1674
1675         list_for_each_entry(s, &mod->unresolved_symbols, list) {
1676                 const char *basename;
1677                 exp = find_symbol(s->name);
1678                 if (!exp) {
1679                         if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1680                                 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR,
1681                                             "\"%s\" [%s.ko] undefined!\n",
1682                                             s->name, mod->name);
1683                         continue;
1684                 }
1685                 if (exp->module == mod) {
1686                         error("\"%s\" [%s.ko] was exported without definition\n",
1687                               s->name, mod->name);
1688                         continue;
1689                 }
1690
1691                 exp->used = true;
1692                 s->module = exp->module;
1693                 s->crc_valid = exp->crc_valid;
1694                 s->crc = exp->crc;
1695
1696                 basename = strrchr(mod->name, '/');
1697                 if (basename)
1698                         basename++;
1699                 else
1700                         basename = mod->name;
1701
1702                 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1703                         modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
1704                                     "module %s uses symbol %s from namespace %s, but does not import it.\n",
1705                                     basename, exp->name, exp->namespace);
1706                         add_namespace(&mod->missing_namespaces, exp->namespace);
1707                 }
1708
1709                 if (!mod->is_gpl_compatible && exp->is_gpl_only)
1710                         error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1711                               basename, exp->name);
1712         }
1713 }
1714
1715 static void handle_white_list_exports(const char *white_list)
1716 {
1717         char *buf, *p, *name;
1718
1719         buf = read_text_file(white_list);
1720         p = buf;
1721
1722         while ((name = strsep(&p, "\n"))) {
1723                 struct symbol *sym = find_symbol(name);
1724
1725                 if (sym)
1726                         sym->used = true;
1727         }
1728
1729         free(buf);
1730 }
1731
1732 static void check_modname_len(struct module *mod)
1733 {
1734         const char *mod_name;
1735
1736         mod_name = strrchr(mod->name, '/');
1737         if (mod_name == NULL)
1738                 mod_name = mod->name;
1739         else
1740                 mod_name++;
1741         if (strlen(mod_name) >= MODULE_NAME_LEN)
1742                 error("module name is too long [%s.ko]\n", mod->name);
1743 }
1744
1745 /**
1746  * Header for the generated file
1747  **/
1748 static void add_header(struct buffer *b, struct module *mod)
1749 {
1750         buf_printf(b, "#include <linux/module.h>\n");
1751         /*
1752          * Include build-salt.h after module.h in order to
1753          * inherit the definitions.
1754          */
1755         buf_printf(b, "#define INCLUDE_VERMAGIC\n");
1756         buf_printf(b, "#include <linux/build-salt.h>\n");
1757         buf_printf(b, "#include <linux/elfnote-lto.h>\n");
1758         buf_printf(b, "#include <linux/export-internal.h>\n");
1759         buf_printf(b, "#include <linux/vermagic.h>\n");
1760         buf_printf(b, "#include <linux/compiler.h>\n");
1761         buf_printf(b, "\n");
1762         buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n");
1763         buf_printf(b, "#include <asm/orc_header.h>\n");
1764         buf_printf(b, "ORC_HEADER;\n");
1765         buf_printf(b, "#endif\n");
1766         buf_printf(b, "\n");
1767         buf_printf(b, "BUILD_SALT;\n");
1768         buf_printf(b, "BUILD_LTO_INFO;\n");
1769         buf_printf(b, "\n");
1770         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1771         buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1772         buf_printf(b, "\n");
1773         buf_printf(b, "__visible struct module __this_module\n");
1774         buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1775         buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1776         if (mod->has_init)
1777                 buf_printf(b, "\t.init = init_module,\n");
1778         if (mod->has_cleanup)
1779                 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1780                               "\t.exit = cleanup_module,\n"
1781                               "#endif\n");
1782         buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1783         buf_printf(b, "};\n");
1784
1785         if (!external_module)
1786                 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1787
1788         buf_printf(b,
1789                    "\n"
1790                    "#ifdef CONFIG_MITIGATION_RETPOLINE\n"
1791                    "MODULE_INFO(retpoline, \"Y\");\n"
1792                    "#endif\n");
1793
1794         if (strstarts(mod->name, "drivers/staging"))
1795                 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1796
1797         if (strstarts(mod->name, "tools/testing"))
1798                 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1799 }
1800
1801 static void add_exported_symbols(struct buffer *buf, struct module *mod)
1802 {
1803         struct symbol *sym;
1804
1805         /* generate struct for exported symbols */
1806         buf_printf(buf, "\n");
1807         list_for_each_entry(sym, &mod->exported_symbols, list) {
1808                 if (trim_unused_exports && !sym->used)
1809                         continue;
1810
1811                 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1812                            sym->is_func ? "FUNC" : "DATA", sym->name,
1813                            sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1814         }
1815
1816         if (!modversions)
1817                 return;
1818
1819         /* record CRCs for exported symbols */
1820         buf_printf(buf, "\n");
1821         list_for_each_entry(sym, &mod->exported_symbols, list) {
1822                 if (trim_unused_exports && !sym->used)
1823                         continue;
1824
1825                 if (!sym->crc_valid)
1826                         warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1827                              "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1828                              sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1829                              sym->name);
1830
1831                 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1832                            sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1833         }
1834 }
1835
1836 /**
1837  * Record CRCs for unresolved symbols
1838  **/
1839 static void add_versions(struct buffer *b, struct module *mod)
1840 {
1841         struct symbol *s;
1842
1843         if (!modversions)
1844                 return;
1845
1846         buf_printf(b, "\n");
1847         buf_printf(b, "static const struct modversion_info ____versions[]\n");
1848         buf_printf(b, "__used __section(\"__versions\") = {\n");
1849
1850         list_for_each_entry(s, &mod->unresolved_symbols, list) {
1851                 if (!s->module)
1852                         continue;
1853                 if (!s->crc_valid) {
1854                         warn("\"%s\" [%s.ko] has no CRC!\n",
1855                                 s->name, mod->name);
1856                         continue;
1857                 }
1858                 if (strlen(s->name) >= MODULE_NAME_LEN) {
1859                         error("too long symbol \"%s\" [%s.ko]\n",
1860                               s->name, mod->name);
1861                         break;
1862                 }
1863                 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
1864                            s->crc, s->name);
1865         }
1866
1867         buf_printf(b, "};\n");
1868 }
1869
1870 static void add_depends(struct buffer *b, struct module *mod)
1871 {
1872         struct symbol *s;
1873         int first = 1;
1874
1875         /* Clear ->seen flag of modules that own symbols needed by this. */
1876         list_for_each_entry(s, &mod->unresolved_symbols, list) {
1877                 if (s->module)
1878                         s->module->seen = s->module->is_vmlinux;
1879         }
1880
1881         buf_printf(b, "\n");
1882         buf_printf(b, "MODULE_INFO(depends, \"");
1883         list_for_each_entry(s, &mod->unresolved_symbols, list) {
1884                 const char *p;
1885                 if (!s->module)
1886                         continue;
1887
1888                 if (s->module->seen)
1889                         continue;
1890
1891                 s->module->seen = true;
1892                 p = strrchr(s->module->name, '/');
1893                 if (p)
1894                         p++;
1895                 else
1896                         p = s->module->name;
1897                 buf_printf(b, "%s%s", first ? "" : ",", p);
1898                 first = 0;
1899         }
1900         buf_printf(b, "\");\n");
1901 }
1902
1903 static void add_srcversion(struct buffer *b, struct module *mod)
1904 {
1905         if (mod->srcversion[0]) {
1906                 buf_printf(b, "\n");
1907                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1908                            mod->srcversion);
1909         }
1910 }
1911
1912 static void write_buf(struct buffer *b, const char *fname)
1913 {
1914         FILE *file;
1915
1916         if (error_occurred)
1917                 return;
1918
1919         file = fopen(fname, "w");
1920         if (!file) {
1921                 perror(fname);
1922                 exit(1);
1923         }
1924         if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1925                 perror(fname);
1926                 exit(1);
1927         }
1928         if (fclose(file) != 0) {
1929                 perror(fname);
1930                 exit(1);
1931         }
1932 }
1933
1934 static void write_if_changed(struct buffer *b, const char *fname)
1935 {
1936         char *tmp;
1937         FILE *file;
1938         struct stat st;
1939
1940         file = fopen(fname, "r");
1941         if (!file)
1942                 goto write;
1943
1944         if (fstat(fileno(file), &st) < 0)
1945                 goto close_write;
1946
1947         if (st.st_size != b->pos)
1948                 goto close_write;
1949
1950         tmp = NOFAIL(malloc(b->pos));
1951         if (fread(tmp, 1, b->pos, file) != b->pos)
1952                 goto free_write;
1953
1954         if (memcmp(tmp, b->p, b->pos) != 0)
1955                 goto free_write;
1956
1957         free(tmp);
1958         fclose(file);
1959         return;
1960
1961  free_write:
1962         free(tmp);
1963  close_write:
1964         fclose(file);
1965  write:
1966         write_buf(b, fname);
1967 }
1968
1969 static void write_vmlinux_export_c_file(struct module *mod)
1970 {
1971         struct buffer buf = { };
1972
1973         buf_printf(&buf,
1974                    "#include <linux/export-internal.h>\n");
1975
1976         add_exported_symbols(&buf, mod);
1977         write_if_changed(&buf, ".vmlinux.export.c");
1978         free(buf.p);
1979 }
1980
1981 /* do sanity checks, and generate *.mod.c file */
1982 static void write_mod_c_file(struct module *mod)
1983 {
1984         struct buffer buf = { };
1985         char fname[PATH_MAX];
1986         int ret;
1987
1988         add_header(&buf, mod);
1989         add_exported_symbols(&buf, mod);
1990         add_versions(&buf, mod);
1991         add_depends(&buf, mod);
1992         add_moddevtable(&buf, mod);
1993         add_srcversion(&buf, mod);
1994
1995         ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
1996         if (ret >= sizeof(fname)) {
1997                 error("%s: too long path was truncated\n", fname);
1998                 goto free;
1999         }
2000
2001         write_if_changed(&buf, fname);
2002
2003 free:
2004         free(buf.p);
2005 }
2006
2007 /* parse Module.symvers file. line format:
2008  * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
2009  **/
2010 static void read_dump(const char *fname)
2011 {
2012         char *buf, *pos, *line;
2013
2014         buf = read_text_file(fname);
2015         if (!buf)
2016                 /* No symbol versions, silently ignore */
2017                 return;
2018
2019         pos = buf;
2020
2021         while ((line = get_line(&pos))) {
2022                 char *symname, *namespace, *modname, *d, *export;
2023                 unsigned int crc;
2024                 struct module *mod;
2025                 struct symbol *s;
2026                 bool gpl_only;
2027
2028                 if (!(symname = strchr(line, '\t')))
2029                         goto fail;
2030                 *symname++ = '\0';
2031                 if (!(modname = strchr(symname, '\t')))
2032                         goto fail;
2033                 *modname++ = '\0';
2034                 if (!(export = strchr(modname, '\t')))
2035                         goto fail;
2036                 *export++ = '\0';
2037                 if (!(namespace = strchr(export, '\t')))
2038                         goto fail;
2039                 *namespace++ = '\0';
2040
2041                 crc = strtoul(line, &d, 16);
2042                 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2043                         goto fail;
2044
2045                 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2046                         gpl_only = true;
2047                 } else if (!strcmp(export, "EXPORT_SYMBOL")) {
2048                         gpl_only = false;
2049                 } else {
2050                         error("%s: unknown license %s. skip", symname, export);
2051                         continue;
2052                 }
2053
2054                 mod = find_module(modname);
2055                 if (!mod) {
2056                         mod = new_module(modname, strlen(modname));
2057                         mod->from_dump = true;
2058                 }
2059                 s = sym_add_exported(symname, mod, gpl_only, namespace);
2060                 sym_set_crc(s, crc);
2061         }
2062         free(buf);
2063         return;
2064 fail:
2065         free(buf);
2066         fatal("parse error in symbol dump file\n");
2067 }
2068
2069 static void write_dump(const char *fname)
2070 {
2071         struct buffer buf = { };
2072         struct module *mod;
2073         struct symbol *sym;
2074
2075         list_for_each_entry(mod, &modules, list) {
2076                 if (mod->from_dump)
2077                         continue;
2078                 list_for_each_entry(sym, &mod->exported_symbols, list) {
2079                         if (trim_unused_exports && !sym->used)
2080                                 continue;
2081
2082                         buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2083                                    sym->crc, sym->name, mod->name,
2084                                    sym->is_gpl_only ? "_GPL" : "",
2085                                    sym->namespace);
2086                 }
2087         }
2088         write_buf(&buf, fname);
2089         free(buf.p);
2090 }
2091
2092 static void write_namespace_deps_files(const char *fname)
2093 {
2094         struct module *mod;
2095         struct namespace_list *ns;
2096         struct buffer ns_deps_buf = {};
2097
2098         list_for_each_entry(mod, &modules, list) {
2099
2100                 if (mod->from_dump || list_empty(&mod->missing_namespaces))
2101                         continue;
2102
2103                 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2104
2105                 list_for_each_entry(ns, &mod->missing_namespaces, list)
2106                         buf_printf(&ns_deps_buf, " %s", ns->namespace);
2107
2108                 buf_printf(&ns_deps_buf, "\n");
2109         }
2110
2111         write_if_changed(&ns_deps_buf, fname);
2112         free(ns_deps_buf.p);
2113 }
2114
2115 struct dump_list {
2116         struct list_head list;
2117         const char *file;
2118 };
2119
2120 int main(int argc, char **argv)
2121 {
2122         struct module *mod;
2123         char *missing_namespace_deps = NULL;
2124         char *unused_exports_white_list = NULL;
2125         char *dump_write = NULL, *files_source = NULL;
2126         int opt;
2127         LIST_HEAD(dump_lists);
2128         struct dump_list *dl, *dl2;
2129
2130         while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
2131                 switch (opt) {
2132                 case 'e':
2133                         external_module = true;
2134                         break;
2135                 case 'i':
2136                         dl = NOFAIL(malloc(sizeof(*dl)));
2137                         dl->file = optarg;
2138                         list_add_tail(&dl->list, &dump_lists);
2139                         break;
2140                 case 'M':
2141                         module_enabled = true;
2142                         break;
2143                 case 'm':
2144                         modversions = true;
2145                         break;
2146                 case 'n':
2147                         ignore_missing_files = true;
2148                         break;
2149                 case 'o':
2150                         dump_write = optarg;
2151                         break;
2152                 case 'a':
2153                         all_versions = true;
2154                         break;
2155                 case 'T':
2156                         files_source = optarg;
2157                         break;
2158                 case 't':
2159                         trim_unused_exports = true;
2160                         break;
2161                 case 'u':
2162                         unused_exports_white_list = optarg;
2163                         break;
2164                 case 'W':
2165                         extra_warn = true;
2166                         break;
2167                 case 'w':
2168                         warn_unresolved = true;
2169                         break;
2170                 case 'E':
2171                         sec_mismatch_warn_only = false;
2172                         break;
2173                 case 'N':
2174                         allow_missing_ns_imports = true;
2175                         break;
2176                 case 'd':
2177                         missing_namespace_deps = optarg;
2178                         break;
2179                 default:
2180                         exit(1);
2181                 }
2182         }
2183
2184         list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2185                 read_dump(dl->file);
2186                 list_del(&dl->list);
2187                 free(dl);
2188         }
2189
2190         while (optind < argc)
2191                 read_symbols(argv[optind++]);
2192
2193         if (files_source)
2194                 read_symbols_from_files(files_source);
2195
2196         list_for_each_entry(mod, &modules, list) {
2197                 if (mod->from_dump || mod->is_vmlinux)
2198                         continue;
2199
2200                 check_modname_len(mod);
2201                 check_exports(mod);
2202         }
2203
2204         if (unused_exports_white_list)
2205                 handle_white_list_exports(unused_exports_white_list);
2206
2207         list_for_each_entry(mod, &modules, list) {
2208                 if (mod->from_dump)
2209                         continue;
2210
2211                 if (mod->is_vmlinux)
2212                         write_vmlinux_export_c_file(mod);
2213                 else
2214                         write_mod_c_file(mod);
2215         }
2216
2217         if (missing_namespace_deps)
2218                 write_namespace_deps_files(missing_namespace_deps);
2219
2220         if (dump_write)
2221                 write_dump(dump_write);
2222         if (sec_mismatch_count && !sec_mismatch_warn_only)
2223                 error("Section mismatches detected.\n"
2224                       "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2225
2226         if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2227                 warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2228                      nr_unresolved - MAX_UNRESOLVED_REPORTS);
2229
2230         return error_occurred ? 1 : 0;
2231 }