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 #include "modpost.h"
  24 #include "../../include/linux/license.h"
  25 #include "../../include/linux/module_symbol.h"
  26
  27 static bool module_enabled;
  28 /* Are we using CONFIG_MODVERSIONS? */
  29 static bool modversions;
  30 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
  31 static bool all_versions;
  32 /* If we are modposting external module set to 1 */
  33 static bool external_module;
  34 /* Only warn about unresolved symbols */
  35 static bool warn_unresolved;
  36
  37 static int sec_mismatch_count;
  38 static bool sec_mismatch_warn_only = true;
  39 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
  40 static bool trim_unused_exports;
  41
  42 /* ignore missing files */
  43 static bool ignore_missing_files;
  44 /* If set to 1, only warn (instead of error) about missing ns imports */
  45 static bool allow_missing_ns_imports;
  46
  47 static bool error_occurred;
  48
  49 static bool extra_warn;
  50
  51 /*
  52  * Cut off the warnings when there are too many. This typically occurs when
  53  * vmlinux is missing. ('make modules' without building vmlinux.)
  54  */
  55 #define MAX_UNRESOLVED_REPORTS  10
  56 static unsigned int nr_unresolved;
  57
  58 /* In kernel, this size is defined in linux/module.h;
  59  * here we use Elf_Addr instead of long for covering cross-compile
  60  */
  61
  62 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
  63
  64 void __attribute__((format(printf, 2, 3)))
  65 modpost_log(enum loglevel loglevel, const char *fmt, ...)
  66 {
  67         va_list arglist;
  68
  69         switch (loglevel) {
  70         case LOG_WARN:
  71                 fprintf(stderr, "WARNING: ");
  72                 break;
  73         case LOG_ERROR:
  74                 fprintf(stderr, "ERROR: ");
  75                 break;
  76         case LOG_FATAL:
  77                 fprintf(stderr, "FATAL: ");
  78                 break;
  79         default: /* invalid loglevel, ignore */
  80                 break;
  81         }
  82
  83         fprintf(stderr, "modpost: ");
  84
  85         va_start(arglist, fmt);
  86         vfprintf(stderr, fmt, arglist);
  87         va_end(arglist);
  88
  89         if (loglevel == LOG_FATAL)
  90                 exit(1);
  91         if (loglevel == LOG_ERROR)
  92                 error_occurred = true;
  93 }
  94
  95 static inline bool strends(const char *str, const char *postfix)
  96 {
  97         if (strlen(str) < strlen(postfix))
  98                 return false;
  99
 100         return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
 101 }
 102
 103 void *do_nofail(void *ptr, const char *expr)
 104 {
 105         if (!ptr)
 106                 fatal("Memory allocation failure: %s.\n", expr);
 107
 108         return ptr;
 109 }
 110
 111 char *read_text_file(const char *filename)
 112 {
 113         struct stat st;
 114         size_t nbytes;
 115         int fd;
 116         char *buf;
 117
 118         fd = open(filename, O_RDONLY);
 119         if (fd < 0) {
 120                 perror(filename);
 121                 exit(1);
 122         }
 123
 124         if (fstat(fd, &st) < 0) {
 125                 perror(filename);
 126                 exit(1);
 127         }
 128
 129         buf = NOFAIL(malloc(st.st_size + 1));
 130
 131         nbytes = st.st_size;
 132
 133         while (nbytes) {
 134                 ssize_t bytes_read;
 135
 136                 bytes_read = read(fd, buf, nbytes);
 137                 if (bytes_read < 0) {
 138                         perror(filename);
 139                         exit(1);
 140                 }
 141
 142                 nbytes -= bytes_read;
 143         }
 144         buf[st.st_size] = '\0';
 145
 146         close(fd);
 147
 148         return buf;
 149 }
 150
 151 char *get_line(char **stringp)
 152 {
 153         char *orig = *stringp, *next;
 154
 155         /* do not return the unwanted extra line at EOF */
 156         if (!orig || *orig == '\0')
 157                 return NULL;
 158
 159         /* don't use strsep here, it is not available everywhere */
 160         next = strchr(orig, '\n');
 161         if (next)
 162                 *next++ = '\0';
 163
 164         *stringp = next;
 165
 166         return orig;
 167 }
 168
 169 /* A list of all modules we processed */
 170 LIST_HEAD(modules);
 171
 172 static struct module *find_module(const char *modname)
 173 {
 174         struct module *mod;
 175
 176         list_for_each_entry(mod, &modules, list) {
 177                 if (strcmp(mod->name, modname) == 0)
 178                         return mod;
 179         }
 180         return NULL;
 181 }
 182
 183 static struct module *new_module(const char *name, size_t namelen)
 184 {
 185         struct module *mod;
 186
 187         mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1));
 188         memset(mod, 0, sizeof(*mod));
 189
 190         INIT_LIST_HEAD(&mod->exported_symbols);
 191         INIT_LIST_HEAD(&mod->unresolved_symbols);
 192         INIT_LIST_HEAD(&mod->missing_namespaces);
 193         INIT_LIST_HEAD(&mod->imported_namespaces);
 194
 195         memcpy(mod->name, name, namelen);
 196         mod->name[namelen] = '\0';
 197         mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
 198
 199         /*
 200          * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
 201          * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
 202          * modpost will exit wiht error anyway.
 203          */
 204         mod->is_gpl_compatible = true;
 205
 206         list_add_tail(&mod->list, &modules);
 207
 208         return mod;
 209 }
 210
 211 /* A hash of all exported symbols,
 212  * struct symbol is also used for lists of unresolved symbols */
 213
 214 #define SYMBOL_HASH_SIZE 1024
 215
 216 struct symbol {
 217         struct symbol *next;
 218         struct list_head list;  /* link to module::exported_symbols or module::unresolved_symbols */
 219         struct module *module;
 220         char *namespace;
 221         unsigned int crc;
 222         bool crc_valid;
 223         bool weak;
 224         bool is_func;
 225         bool is_gpl_only;       /* exported by EXPORT_SYMBOL_GPL */
 226         bool used;              /* there exists a user of this symbol */
 227         char name[];
 228 };
 229
 230 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
 231
 232 /* This is based on the hash algorithm from gdbm, via tdb */
 233 static inline unsigned int tdb_hash(const char *name)
 234 {
 235         unsigned value; /* Used to compute the hash value.  */
 236         unsigned   i;   /* Used to cycle through random values. */
 237
 238         /* Set the initial value from the key size. */
 239         for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
 240                 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
 241
 242         return (1103515243 * value + 12345);
 243 }
 244
 245 /**
 246  * Allocate a new symbols for use in the hash of exported symbols or
 247  * the list of unresolved symbols per module
 248  **/
 249 static struct symbol *alloc_symbol(const char *name)
 250 {
 251         struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
 252
 253         memset(s, 0, sizeof(*s));
 254         strcpy(s->name, name);
 255
 256         return s;
 257 }
 258
 259 /* For the hash of exported symbols */
 260 static void hash_add_symbol(struct symbol *sym)
 261 {
 262         unsigned int hash;
 263
 264         hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE;
 265         sym->next = symbolhash[hash];
 266         symbolhash[hash] = sym;
 267 }
 268
 269 static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
 270 {
 271         struct symbol *sym;
 272
 273         sym = alloc_symbol(name);
 274         sym->weak = weak;
 275
 276         list_add_tail(&sym->list, &mod->unresolved_symbols);
 277 }
 278
 279 static struct symbol *sym_find_with_module(const char *name, struct module *mod)
 280 {
 281         struct symbol *s;
 282
 283         /* For our purposes, .foo matches foo.  PPC64 needs this. */
 284         if (name[0] == '.')
 285                 name++;
 286
 287         for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
 288                 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
 289                         return s;
 290         }
 291         return NULL;
 292 }
 293
 294 static struct symbol *find_symbol(const char *name)
 295 {
 296         return sym_find_with_module(name, NULL);
 297 }
 298
 299 struct namespace_list {
 300         struct list_head list;
 301         char namespace[];
 302 };
 303
 304 static bool contains_namespace(struct list_head *head, const char *namespace)
 305 {
 306         struct namespace_list *list;
 307
 308         /*
 309          * The default namespace is null string "", which is always implicitly
 310          * contained.
 311          */
 312         if (!namespace[0])
 313                 return true;
 314
 315         list_for_each_entry(list, head, list) {
 316                 if (!strcmp(list->namespace, namespace))
 317                         return true;
 318         }
 319
 320         return false;
 321 }
 322
 323 static void add_namespace(struct list_head *head, const char *namespace)
 324 {
 325         struct namespace_list *ns_entry;
 326
 327         if (!contains_namespace(head, namespace)) {
 328                 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) +
 329                                          strlen(namespace) + 1));
 330                 strcpy(ns_entry->namespace, namespace);
 331                 list_add_tail(&ns_entry->list, head);
 332         }
 333 }
 334
 335 static void *sym_get_data_by_offset(const struct elf_info *info,
 336                                     unsigned int secindex, unsigned long offset)
 337 {
 338         Elf_Shdr *sechdr = &info->sechdrs[secindex];
 339
 340         return (void *)info->hdr + sechdr->sh_offset + offset;
 341 }
 342
 343 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
 344 {
 345         return sym_get_data_by_offset(info, get_secindex(info, sym),
 346                                       sym->st_value);
 347 }
 348
 349 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
 350 {
 351         return sym_get_data_by_offset(info, info->secindex_strings,
 352                                       sechdr->sh_name);
 353 }
 354
 355 static const char *sec_name(const struct elf_info *info, unsigned int secindex)
 356 {
 357         /*
 358          * If sym->st_shndx is a special section index, there is no
 359          * corresponding section header.
 360          * Return "" if the index is out of range of info->sechdrs[] array.
 361          */
 362         if (secindex >= info->num_sections)
 363                 return "";
 364
 365         return sech_name(info, &info->sechdrs[secindex]);
 366 }
 367
 368 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
 369
 370 static struct symbol *sym_add_exported(const char *name, struct module *mod,
 371                                        bool gpl_only, const char *namespace)
 372 {
 373         struct symbol *s = find_symbol(name);
 374
 375         if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
 376                 error("%s: '%s' exported twice. Previous export was in %s%s\n",
 377                       mod->name, name, s->module->name,
 378                       s->module->is_vmlinux ? "" : ".ko");
 379         }
 380
 381         s = alloc_symbol(name);
 382         s->module = mod;
 383         s->is_gpl_only = gpl_only;
 384         s->namespace = NOFAIL(strdup(namespace));
 385         list_add_tail(&s->list, &mod->exported_symbols);
 386         hash_add_symbol(s);
 387
 388         return s;
 389 }
 390
 391 static void sym_set_crc(struct symbol *sym, unsigned int crc)
 392 {
 393         sym->crc = crc;
 394         sym->crc_valid = true;
 395 }
 396
 397 static void *grab_file(const char *filename, size_t *size)
 398 {
 399         struct stat st;
 400         void *map = MAP_FAILED;
 401         int fd;
 402
 403         fd = open(filename, O_RDONLY);
 404         if (fd < 0)
 405                 return NULL;
 406         if (fstat(fd, &st))
 407                 goto failed;
 408
 409         *size = st.st_size;
 410         map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 411
 412 failed:
 413         close(fd);
 414         if (map == MAP_FAILED)
 415                 return NULL;
 416         return map;
 417 }
 418
 419 static void release_file(void *file, size_t size)
 420 {
 421         munmap(file, size);
 422 }
 423
 424 static int parse_elf(struct elf_info *info, const char *filename)
 425 {
 426         unsigned int i;
 427         Elf_Ehdr *hdr;
 428         Elf_Shdr *sechdrs;
 429         Elf_Sym  *sym;
 430         const char *secstrings;
 431         unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
 432
 433         hdr = grab_file(filename, &info->size);
 434         if (!hdr) {
 435                 if (ignore_missing_files) {
 436                         fprintf(stderr, "%s: %s (ignored)\n", filename,
 437                                 strerror(errno));
 438                         return 0;
 439                 }
 440                 perror(filename);
 441                 exit(1);
 442         }
 443         info->hdr = hdr;
 444         if (info->size < sizeof(*hdr)) {
 445                 /* file too small, assume this is an empty .o file */
 446                 return 0;
 447         }
 448         /* Is this a valid ELF file? */
 449         if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 450             (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 451             (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 452             (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 453                 /* Not an ELF file - silently ignore it */
 454                 return 0;
 455         }
 456         /* Fix endianness in ELF header */
 457         hdr->e_type      = TO_NATIVE(hdr->e_type);
 458         hdr->e_machine   = TO_NATIVE(hdr->e_machine);
 459         hdr->e_version   = TO_NATIVE(hdr->e_version);
 460         hdr->e_entry     = TO_NATIVE(hdr->e_entry);
 461         hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
 462         hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
 463         hdr->e_flags     = TO_NATIVE(hdr->e_flags);
 464         hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
 465         hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
 466         hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
 467         hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
 468         hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
 469         hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
 470         sechdrs = (void *)hdr + hdr->e_shoff;
 471         info->sechdrs = sechdrs;
 472
 473         /* modpost only works for relocatable objects */
 474         if (hdr->e_type != ET_REL)
 475                 fatal("%s: not relocatable object.", filename);
 476
 477         /* Check if file offset is correct */
 478         if (hdr->e_shoff > info->size) {
 479                 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
 480                       (unsigned long)hdr->e_shoff, filename, info->size);
 481                 return 0;
 482         }
 483
 484         if (hdr->e_shnum == SHN_UNDEF) {
 485                 /*
 486                  * There are more than 64k sections,
 487                  * read count from .sh_size.
 488                  */
 489                 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
 490         }
 491         else {
 492                 info->num_sections = hdr->e_shnum;
 493         }
 494         if (hdr->e_shstrndx == SHN_XINDEX) {
 495                 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
 496         }
 497         else {
 498                 info->secindex_strings = hdr->e_shstrndx;
 499         }
 500
 501         /* Fix endianness in section headers */
 502         for (i = 0; i < info->num_sections; i++) {
 503                 sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
 504                 sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
 505                 sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
 506                 sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
 507                 sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
 508                 sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
 509                 sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
 510                 sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
 511                 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
 512                 sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
 513         }
 514         /* Find symbol table. */
 515         secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
 516         for (i = 1; i < info->num_sections; i++) {
 517                 const char *secname;
 518                 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
 519
 520                 if (!nobits && sechdrs[i].sh_offset > info->size) {
 521                         fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
 522                               filename, (unsigned long)sechdrs[i].sh_offset,
 523                               sizeof(*hdr));
 524                         return 0;
 525                 }
 526                 secname = secstrings + sechdrs[i].sh_name;
 527                 if (strcmp(secname, ".modinfo") == 0) {
 528                         if (nobits)
 529                                 fatal("%s has NOBITS .modinfo\n", filename);
 530                         info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 531                         info->modinfo_len = sechdrs[i].sh_size;
 532                 } else if (!strcmp(secname, ".export_symbol")) {
 533                         info->export_symbol_secndx = i;
 534                 }
 535
 536                 if (sechdrs[i].sh_type == SHT_SYMTAB) {
 537                         unsigned int sh_link_idx;
 538                         symtab_idx = i;
 539                         info->symtab_start = (void *)hdr +
 540                             sechdrs[i].sh_offset;
 541                         info->symtab_stop  = (void *)hdr +
 542                             sechdrs[i].sh_offset + sechdrs[i].sh_size;
 543                         sh_link_idx = sechdrs[i].sh_link;
 544                         info->strtab       = (void *)hdr +
 545                             sechdrs[sh_link_idx].sh_offset;
 546                 }
 547
 548                 /* 32bit section no. table? ("more than 64k sections") */
 549                 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
 550                         symtab_shndx_idx = i;
 551                         info->symtab_shndx_start = (void *)hdr +
 552                             sechdrs[i].sh_offset;
 553                         info->symtab_shndx_stop  = (void *)hdr +
 554                             sechdrs[i].sh_offset + sechdrs[i].sh_size;
 555                 }
 556         }
 557         if (!info->symtab_start)
 558                 fatal("%s has no symtab?\n", filename);
 559
 560         /* Fix endianness in symbols */
 561         for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 562                 sym->st_shndx = TO_NATIVE(sym->st_shndx);
 563                 sym->st_name  = TO_NATIVE(sym->st_name);
 564                 sym->st_value = TO_NATIVE(sym->st_value);
 565                 sym->st_size  = TO_NATIVE(sym->st_size);
 566         }
 567
 568         if (symtab_shndx_idx != ~0U) {
 569                 Elf32_Word *p;
 570                 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
 571                         fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
 572                               filename, sechdrs[symtab_shndx_idx].sh_link,
 573                               symtab_idx);
 574                 /* Fix endianness */
 575                 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
 576                      p++)
 577                         *p = TO_NATIVE(*p);
 578         }
 579
 580         return 1;
 581 }
 582
 583 static void parse_elf_finish(struct elf_info *info)
 584 {
 585         release_file(info->hdr, info->size);
 586 }
 587
 588 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 589 {
 590         /* ignore __this_module, it will be resolved shortly */
 591         if (strcmp(symname, "__this_module") == 0)
 592                 return 1;
 593         /* ignore global offset table */
 594         if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 595                 return 1;
 596         if (info->hdr->e_machine == EM_PPC)
 597                 /* Special register function linked on all modules during final link of .ko */
 598                 if (strstarts(symname, "_restgpr_") ||
 599                     strstarts(symname, "_savegpr_") ||
 600                     strstarts(symname, "_rest32gpr_") ||
 601                     strstarts(symname, "_save32gpr_") ||
 602                     strstarts(symname, "_restvr_") ||
 603                     strstarts(symname, "_savevr_"))
 604                         return 1;
 605         if (info->hdr->e_machine == EM_PPC64)
 606                 /* Special register function linked on all modules during final link of .ko */
 607                 if (strstarts(symname, "_restgpr0_") ||
 608                     strstarts(symname, "_savegpr0_") ||
 609                     strstarts(symname, "_restvr_") ||
 610                     strstarts(symname, "_savevr_") ||
 611                     strcmp(symname, ".TOC.") == 0)
 612                         return 1;
 613
 614         if (info->hdr->e_machine == EM_S390)
 615                 /* Expoline thunks are linked on all kernel modules during final link of .ko */
 616                 if (strstarts(symname, "__s390_indirect_jump_r"))
 617                         return 1;
 618         /* Do not ignore this symbol */
 619         return 0;
 620 }
 621
 622 static void handle_symbol(struct module *mod, struct elf_info *info,
 623                           const Elf_Sym *sym, const char *symname)
 624 {
 625         switch (sym->st_shndx) {
 626         case SHN_COMMON:
 627                 if (strstarts(symname, "__gnu_lto_")) {
 628                         /* Should warn here, but modpost runs before the linker */
 629                 } else
 630                         warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 631                 break;
 632         case SHN_UNDEF:
 633                 /* undefined symbol */
 634                 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 635                     ELF_ST_BIND(sym->st_info) != STB_WEAK)
 636                         break;
 637                 if (ignore_undef_symbol(info, symname))
 638                         break;
 639                 if (info->hdr->e_machine == EM_SPARC ||
 640                     info->hdr->e_machine == EM_SPARCV9) {
 641                         /* Ignore register directives. */
 642                         if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 643                                 break;
 644                         if (symname[0] == '.') {
 645                                 char *munged = NOFAIL(strdup(symname));
 646                                 munged[0] = '_';
 647                                 munged[1] = toupper(munged[1]);
 648                                 symname = munged;
 649                         }
 650                 }
 651
 652                 sym_add_unresolved(symname, mod,
 653                                    ELF_ST_BIND(sym->st_info) == STB_WEAK);
 654                 break;
 655         default:
 656                 if (strcmp(symname, "init_module") == 0)
 657                         mod->has_init = true;
 658                 if (strcmp(symname, "cleanup_module") == 0)
 659                         mod->has_cleanup = true;
 660                 break;
 661         }
 662 }
 663
 664 /**
 665  * Parse tag=value strings from .modinfo section
 666  **/
 667 static char *next_string(char *string, unsigned long *secsize)
 668 {
 669         /* Skip non-zero chars */
 670         while (string[0]) {
 671                 string++;
 672                 if ((*secsize)-- <= 1)
 673                         return NULL;
 674         }
 675
 676         /* Skip any zero padding. */
 677         while (!string[0]) {
 678                 string++;
 679                 if ((*secsize)-- <= 1)
 680                         return NULL;
 681         }
 682         return string;
 683 }
 684
 685 static char *get_next_modinfo(struct elf_info *info, const char *tag,
 686                               char *prev)
 687 {
 688         char *p;
 689         unsigned int taglen = strlen(tag);
 690         char *modinfo = info->modinfo;
 691         unsigned long size = info->modinfo_len;
 692
 693         if (prev) {
 694                 size -= prev - modinfo;
 695                 modinfo = next_string(prev, &size);
 696         }
 697
 698         for (p = modinfo; p; p = next_string(p, &size)) {
 699                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 700                         return p + taglen + 1;
 701         }
 702         return NULL;
 703 }
 704
 705 static char *get_modinfo(struct elf_info *info, const char *tag)
 706
 707 {
 708         return get_next_modinfo(info, tag, NULL);
 709 }
 710
 711 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
 712 {
 713         if (sym)
 714                 return elf->strtab + sym->st_name;
 715         else
 716                 return "(unknown)";
 717 }
 718
 719 /*
 720  * Check whether the 'string' argument matches one of the 'patterns',
 721  * an array of shell wildcard patterns (glob).
 722  *
 723  * Return true is there is a match.
 724  */
 725 static bool match(const char *string, const char *const patterns[])
 726 {
 727         const char *pattern;
 728
 729         while ((pattern = *patterns++)) {
 730                 if (!fnmatch(pattern, string, 0))
 731                         return true;
 732         }
 733
 734         return false;
 735 }
 736
 737 /* useful to pass patterns to match() directly */
 738 #define PATTERNS(...) \
 739         ({ \
 740                 static const char *const patterns[] = {__VA_ARGS__, NULL}; \
 741                 patterns; \
 742         })
 743
 744 /* sections that we do not want to do full section mismatch check on */
 745 static const char *const section_white_list[] =
 746 {
 747         ".comment*",
 748         ".debug*",
 749         ".zdebug*",             /* Compressed debug sections. */
 750         ".GCC.command.line",    /* record-gcc-switches */
 751         ".mdebug*",        /* alpha, score, mips etc. */
 752         ".pdr",            /* alpha, score, mips etc. */
 753         ".stab*",
 754         ".note*",
 755         ".got*",
 756         ".toc*",
 757         ".xt.prop",                              /* xtensa */
 758         ".xt.lit",         /* xtensa */
 759         ".arcextmap*",                  /* arc */
 760         ".gnu.linkonce.arcext*",        /* arc : modules */
 761         ".cmem*",                       /* EZchip */
 762         ".fmt_slot*",                   /* EZchip */
 763         ".gnu.lto*",
 764         ".discard.*",
 765         ".llvm.call-graph-profile",     /* call graph */
 766         NULL
 767 };
 768
 769 /*
 770  * This is used to find sections missing the SHF_ALLOC flag.
 771  * The cause of this is often a section specified in assembler
 772  * without "ax" / "aw".
 773  */
 774 static void check_section(const char *modname, struct elf_info *elf,
 775                           Elf_Shdr *sechdr)
 776 {
 777         const char *sec = sech_name(elf, sechdr);
 778
 779         if (sechdr->sh_type == SHT_PROGBITS &&
 780             !(sechdr->sh_flags & SHF_ALLOC) &&
 781             !match(sec, section_white_list)) {
 782                 warn("%s (%s): unexpected non-allocatable section.\n"
 783                      "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
 784                      "Note that for example <linux/init.h> contains\n"
 785                      "section definitions for use in .S files.\n\n",
 786                      modname, sec);
 787         }
 788 }
 789
 790
 791
 792 #define ALL_INIT_DATA_SECTIONS \
 793         ".init.setup", ".init.rodata", ".meminit.rodata", \
 794         ".init.data", ".meminit.data"
 795 #define ALL_EXIT_DATA_SECTIONS \
 796         ".exit.data", ".memexit.data"
 797
 798 #define ALL_INIT_TEXT_SECTIONS \
 799         ".init.text", ".meminit.text"
 800 #define ALL_EXIT_TEXT_SECTIONS \
 801         ".exit.text", ".memexit.text"
 802
 803 #define ALL_PCI_INIT_SECTIONS   \
 804         ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
 805         ".pci_fixup_enable", ".pci_fixup_resume", \
 806         ".pci_fixup_resume_early", ".pci_fixup_suspend"
 807
 808 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
 809 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
 810
 811 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
 812 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
 813
 814 #define DATA_SECTIONS ".data", ".data.rel"
 815 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
 816                 ".kprobes.text", ".cpuidle.text", ".noinstr.text"
 817 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
 818                 ".fixup", ".entry.text", ".exception.text", \
 819                 ".coldtext", ".softirqentry.text"
 820
 821 #define INIT_SECTIONS      ".init.*"
 822 #define MEM_INIT_SECTIONS  ".meminit.*"
 823
 824 #define EXIT_SECTIONS      ".exit.*"
 825 #define MEM_EXIT_SECTIONS  ".memexit.*"
 826
 827 #define ALL_TEXT_SECTIONS  ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \
 828                 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
 829
 830 enum mismatch {
 831         TEXT_TO_ANY_INIT,
 832         DATA_TO_ANY_INIT,
 833         TEXTDATA_TO_ANY_EXIT,
 834         XXXINIT_TO_SOME_INIT,
 835         XXXEXIT_TO_SOME_EXIT,
 836         ANY_INIT_TO_ANY_EXIT,
 837         ANY_EXIT_TO_ANY_INIT,
 838         EXTABLE_TO_NON_TEXT,
 839 };
 840
 841 /**
 842  * Describe how to match sections on different criteria:
 843  *
 844  * @fromsec: Array of sections to be matched.
 845  *
 846  * @bad_tosec: Relocations applied to a section in @fromsec to a section in
 847  * this array is forbidden (black-list).  Can be empty.
 848  *
 849  * @good_tosec: Relocations applied to a section in @fromsec must be
 850  * targeting sections in this array (white-list).  Can be empty.
 851  *
 852  * @mismatch: Type of mismatch.
 853  */
 854 struct sectioncheck {
 855         const char *fromsec[20];
 856         const char *bad_tosec[20];
 857         const char *good_tosec[20];
 858         enum mismatch mismatch;
 859 };
 860
 861 static const struct sectioncheck sectioncheck[] = {
 862 /* Do not reference init/exit code/data from
 863  * normal code and data
 864  */
 865 {
 866         .fromsec = { TEXT_SECTIONS, NULL },
 867         .bad_tosec = { ALL_INIT_SECTIONS, NULL },
 868         .mismatch = TEXT_TO_ANY_INIT,
 869 },
 870 {
 871         .fromsec = { DATA_SECTIONS, NULL },
 872         .bad_tosec = { ALL_XXXINIT_SECTIONS, INIT_SECTIONS, NULL },
 873         .mismatch = DATA_TO_ANY_INIT,
 874 },
 875 {
 876         .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
 877         .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
 878         .mismatch = TEXTDATA_TO_ANY_EXIT,
 879 },
 880 /* Do not reference init code/data from meminit code/data */
 881 {
 882         .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
 883         .bad_tosec = { INIT_SECTIONS, NULL },
 884         .mismatch = XXXINIT_TO_SOME_INIT,
 885 },
 886 /* Do not reference exit code/data from memexit code/data */
 887 {
 888         .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
 889         .bad_tosec = { EXIT_SECTIONS, NULL },
 890         .mismatch = XXXEXIT_TO_SOME_EXIT,
 891 },
 892 /* Do not use exit code/data from init code */
 893 {
 894         .fromsec = { ALL_INIT_SECTIONS, NULL },
 895         .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
 896         .mismatch = ANY_INIT_TO_ANY_EXIT,
 897 },
 898 /* Do not use init code/data from exit code */
 899 {
 900         .fromsec = { ALL_EXIT_SECTIONS, NULL },
 901         .bad_tosec = { ALL_INIT_SECTIONS, NULL },
 902         .mismatch = ANY_EXIT_TO_ANY_INIT,
 903 },
 904 {
 905         .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
 906         .bad_tosec = { INIT_SECTIONS, NULL },
 907         .mismatch = ANY_INIT_TO_ANY_EXIT,
 908 },
 909 {
 910         .fromsec = { "__ex_table", NULL },
 911         /* If you're adding any new black-listed sections in here, consider
 912          * adding a special 'printer' for them in scripts/check_extable.
 913          */
 914         .bad_tosec = { ".altinstr_replacement", NULL },
 915         .good_tosec = {ALL_TEXT_SECTIONS , NULL},
 916         .mismatch = EXTABLE_TO_NON_TEXT,
 917 }
 918 };
 919
 920 static const struct sectioncheck *section_mismatch(
 921                 const char *fromsec, const char *tosec)
 922 {
 923         int i;
 924
 925         /*
 926          * The target section could be the SHT_NUL section when we're
 927          * handling relocations to un-resolved symbols, trying to match it
 928          * doesn't make much sense and causes build failures on parisc
 929          * architectures.
 930          */
 931         if (*tosec == '\0')
 932                 return NULL;
 933
 934         for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
 935                 const struct sectioncheck *check = &sectioncheck[i];
 936
 937                 if (match(fromsec, check->fromsec)) {
 938                         if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
 939                                 return check;
 940                         if (check->good_tosec[0] && !match(tosec, check->good_tosec))
 941                                 return check;
 942                 }
 943         }
 944         return NULL;
 945 }
 946
 947 /**
 948  * Whitelist to allow certain references to pass with no warning.
 949  *
 950  * Pattern 1:
 951  *   If a module parameter is declared __initdata and permissions=0
 952  *   then this is legal despite the warning generated.
 953  *   We cannot see value of permissions here, so just ignore
 954  *   this pattern.
 955  *   The pattern is identified by:
 956  *   tosec   = .init.data
 957  *   fromsec = .data*
 958  *   atsym   =__param*
 959  *
 960  * Pattern 1a:
 961  *   module_param_call() ops can refer to __init set function if permissions=0
 962  *   The pattern is identified by:
 963  *   tosec   = .init.text
 964  *   fromsec = .data*
 965  *   atsym   = __param_ops_*
 966  *
 967  * Pattern 3:
 968  *   Whitelist all references from .head.text to any init section
 969  *
 970  * Pattern 4:
 971  *   Some symbols belong to init section but still it is ok to reference
 972  *   these from non-init sections as these symbols don't have any memory
 973  *   allocated for them and symbol address and value are same. So even
 974  *   if init section is freed, its ok to reference those symbols.
 975  *   For ex. symbols marking the init section boundaries.
 976  *   This pattern is identified by
 977  *   refsymname = __init_begin, _sinittext, _einittext
 978  *
 979  * Pattern 5:
 980  *   GCC may optimize static inlines when fed constant arg(s) resulting
 981  *   in functions like cpumask_empty() -- generating an associated symbol
 982  *   cpumask_empty.constprop.3 that appears in the audit.  If the const that
 983  *   is passed in comes from __init, like say nmi_ipi_mask, we get a
 984  *   meaningless section warning.  May need to add isra symbols too...
 985  *   This pattern is identified by
 986  *   tosec   = init section
 987  *   fromsec = text section
 988  *   refsymname = *.constprop.*
 989  *
 990  **/
 991 static int secref_whitelist(const char *fromsec, const char *fromsym,
 992                             const char *tosec, const char *tosym)
 993 {
 994         /* Check for pattern 1 */
 995         if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
 996             match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 997             strstarts(fromsym, "__param"))
 998                 return 0;
 999
1000         /* Check for pattern 1a */
1001         if (strcmp(tosec, ".init.text") == 0 &&
1002             match(fromsec, PATTERNS(DATA_SECTIONS)) &&
1003             strstarts(fromsym, "__param_ops_"))
1004                 return 0;
1005
1006         /* symbols in data sections that may refer to any init/exit sections */
1007         if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
1008             match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
1009             match(fromsym, PATTERNS("*_template", // scsi uses *_template a lot
1010                                     "*_timer", // arm uses ops structures named _timer a lot
1011                                     "*_sht", // scsi also used *_sht to some extent
1012                                     "*_ops",
1013                                     "*_probe",
1014                                     "*_probe_one",
1015                                     "*_console")))
1016                 return 0;
1017
1018         /* symbols in data sections that may refer to meminit sections */
1019         if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
1020             match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS, ALL_XXXEXIT_SECTIONS)) &&
1021             match(fromsym, PATTERNS("*driver")))
1022                 return 0;
1023
1024         /*
1025          * symbols in data sections must not refer to .exit.*, but there are
1026          * quite a few offenders, so hide these unless for W=1 builds until
1027          * these are fixed.
1028          */
1029         if (!extra_warn &&
1030             match(fromsec, PATTERNS(DATA_SECTIONS)) &&
1031             match(tosec, PATTERNS(EXIT_SECTIONS)) &&
1032             match(fromsym, PATTERNS("*driver")))
1033                 return 0;
1034
1035         /* Check for pattern 3 */
1036         if (strstarts(fromsec, ".head.text") &&
1037             match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
1038                 return 0;
1039
1040         /* Check for pattern 4 */
1041         if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
1042                 return 0;
1043
1044         /* Check for pattern 5 */
1045         if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
1046             match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
1047             match(fromsym, PATTERNS("*.constprop.*")))
1048                 return 0;
1049
1050         return 1;
1051 }
1052
1053 /*
1054  * If there's no name there, ignore it; likewise, ignore it if it's
1055  * one of the magic symbols emitted used by current tools.
1056  *
1057  * Otherwise if find_symbols_between() returns those symbols, they'll
1058  * fail the whitelist tests and cause lots of false alarms ... fixable
1059  * only by merging __exit and __init sections into __text, bloating
1060  * the kernel (which is especially evil on embedded platforms).
1061  */
1062 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1063 {
1064         const char *name = elf->strtab + sym->st_name;
1065
1066         if (!name || !strlen(name))
1067                 return 0;
1068         return !is_mapping_symbol(name);
1069 }
1070
1071 /* Look up the nearest symbol based on the section and the address */
1072 static Elf_Sym *find_nearest_sym(struct elf_info *elf, Elf_Addr addr,
1073                                  unsigned int secndx, bool allow_negative,
1074                                  Elf_Addr min_distance)
1075 {
1076         Elf_Sym *sym;
1077         Elf_Sym *near = NULL;
1078         Elf_Addr sym_addr, distance;
1079         bool is_arm = (elf->hdr->e_machine == EM_ARM);
1080
1081         for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1082                 if (get_secindex(elf, sym) != secndx)
1083                         continue;
1084                 if (!is_valid_name(elf, sym))
1085                         continue;
1086
1087                 sym_addr = sym->st_value;
1088
1089                 /*
1090                  * For ARM Thumb instruction, the bit 0 of st_value is set
1091                  * if the symbol is STT_FUNC type. Mask it to get the address.
1092                  */
1093                 if (is_arm && ELF_ST_TYPE(sym->st_info) == STT_FUNC)
1094                          sym_addr &= ~1;
1095
1096                 if (addr >= sym_addr)
1097                         distance = addr - sym_addr;
1098                 else if (allow_negative)
1099                         distance = sym_addr - addr;
1100                 else
1101                         continue;
1102
1103                 if (distance <= min_distance) {
1104                         min_distance = distance;
1105                         near = sym;
1106                 }
1107
1108                 if (min_distance == 0)
1109                         break;
1110         }
1111         return near;
1112 }
1113
1114 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
1115                              unsigned int secndx)
1116 {
1117         return find_nearest_sym(elf, addr, secndx, false, ~0);
1118 }
1119
1120 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
1121 {
1122         /* If the supplied symbol has a valid name, return it */
1123         if (is_valid_name(elf, sym))
1124                 return sym;
1125
1126         /*
1127          * Strive to find a better symbol name, but the resulting name may not
1128          * match the symbol referenced in the original code.
1129          */
1130         return find_nearest_sym(elf, addr, get_secindex(elf, sym), true, 20);
1131 }
1132
1133 static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
1134 {
1135         if (secndx >= elf->num_sections)
1136                 return false;
1137
1138         return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
1139 }
1140
1141 static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1142                                      const struct sectioncheck* const mismatch,
1143                                      Elf_Sym *tsym,
1144                                      unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
1145                                      const char *tosec, Elf_Addr taddr)
1146 {
1147         Elf_Sym *from;
1148         const char *tosym;
1149         const char *fromsym;
1150
1151         from = find_fromsym(elf, faddr, fsecndx);
1152         fromsym = sym_name(elf, from);
1153
1154         tsym = find_tosym(elf, taddr, tsym);
1155         tosym = sym_name(elf, tsym);
1156
1157         /* check whitelist - we may ignore it */
1158         if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1159                 return;
1160
1161         sec_mismatch_count++;
1162
1163         warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n",
1164              modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec);
1165
1166         if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1167                 if (match(tosec, mismatch->bad_tosec))
1168                         fatal("The relocation at %s+0x%lx references\n"
1169                               "section \"%s\" which is black-listed.\n"
1170                               "Something is seriously wrong and should be fixed.\n"
1171                               "You might get more information about where this is\n"
1172                               "coming from by using scripts/check_extable.sh %s\n",
1173                               fromsec, (long)faddr, tosec, modname);
1174                 else if (is_executable_section(elf, get_secindex(elf, tsym)))
1175                         warn("The relocation at %s+0x%lx references\n"
1176                              "section \"%s\" which is not in the list of\n"
1177                              "authorized sections.  If you're adding a new section\n"
1178                              "and/or if this reference is valid, add \"%s\" to the\n"
1179                              "list of authorized sections to jump to on fault.\n"
1180                              "This can be achieved by adding \"%s\" to\n"
1181                              "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1182                              fromsec, (long)faddr, tosec, tosec, tosec);
1183                 else
1184                         error("%s+0x%lx references non-executable section '%s'\n",
1185                               fromsec, (long)faddr, tosec);
1186         }
1187 }
1188
1189 static void check_export_symbol(struct module *mod, struct elf_info *elf,
1190                                 Elf_Addr faddr, const char *secname,
1191                                 Elf_Sym *sym)
1192 {
1193         static const char *prefix = "__export_symbol_";
1194         const char *label_name, *name, *data;
1195         Elf_Sym *label;
1196         struct symbol *s;
1197         bool is_gpl;
1198
1199         label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1200         label_name = sym_name(elf, label);
1201
1202         if (!strstarts(label_name, prefix)) {
1203                 error("%s: .export_symbol section contains strange symbol '%s'\n",
1204                       mod->name, label_name);
1205                 return;
1206         }
1207
1208         if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1209             ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1210                 error("%s: local symbol '%s' was exported\n", mod->name,
1211                       label_name + strlen(prefix));
1212                 return;
1213         }
1214
1215         name = sym_name(elf, sym);
1216         if (strcmp(label_name + strlen(prefix), name)) {
1217                 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1218                       mod->name, name);
1219                 return;
1220         }
1221
1222         data = sym_get_data(elf, label);        /* license */
1223         if (!strcmp(data, "GPL")) {
1224                 is_gpl = true;
1225         } else if (!strcmp(data, "")) {
1226                 is_gpl = false;
1227         } else {
1228                 error("%s: unknown license '%s' was specified for '%s'\n",
1229                       mod->name, data, name);
1230                 return;
1231         }
1232
1233         data += strlen(data) + 1;       /* namespace */
1234         s = sym_add_exported(name, mod, is_gpl, data);
1235
1236         /*
1237          * We need to be aware whether we are exporting a function or
1238          * a data on some architectures.
1239          */
1240         s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1241
1242         /*
1243          * For parisc64, symbols prefixed $$ from the library have the symbol type
1244          * STT_LOPROC. They should be handled as functions too.
1245          */
1246         if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1247             elf->hdr->e_machine == EM_PARISC &&
1248             ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1249                 s->is_func = true;
1250
1251         if (match(secname, PATTERNS(INIT_SECTIONS)))
1252                 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1253                      mod->name, name);
1254         else if (match(secname, PATTERNS(EXIT_SECTIONS)))
1255                 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1256                      mod->name, name);
1257 }
1258
1259 static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1260                                    Elf_Sym *sym,
1261                                    unsigned int fsecndx, const char *fromsec,
1262                                    Elf_Addr faddr, Elf_Addr taddr)
1263 {
1264         const char *tosec = sec_name(elf, get_secindex(elf, sym));
1265         const struct sectioncheck *mismatch;
1266
1267         if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1268                 check_export_symbol(mod, elf, faddr, tosec, sym);
1269                 return;
1270         }
1271
1272         mismatch = section_mismatch(fromsec, tosec);
1273         if (!mismatch)
1274                 return;
1275
1276         default_mismatch_handler(mod->name, elf, mismatch, sym,
1277                                  fsecndx, fromsec, faddr,
1278                                  tosec, taddr);
1279 }
1280
1281 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1282 {
1283         switch (r_type) {
1284         case R_386_32:
1285                 return TO_NATIVE(*location);
1286         case R_386_PC32:
1287                 return TO_NATIVE(*location) + 4;
1288         }
1289
1290         return (Elf_Addr)(-1);
1291 }
1292
1293 #ifndef R_ARM_CALL
1294 #define R_ARM_CALL      28
1295 #endif
1296 #ifndef R_ARM_JUMP24
1297 #define R_ARM_JUMP24    29
1298 #endif
1299
1300 #ifndef R_ARM_THM_CALL
1301 #define R_ARM_THM_CALL          10
1302 #endif
1303 #ifndef R_ARM_THM_JUMP24
1304 #define R_ARM_THM_JUMP24        30
1305 #endif
1306
1307 #ifndef R_ARM_MOVW_ABS_NC
1308 #define R_ARM_MOVW_ABS_NC       43
1309 #endif
1310
1311 #ifndef R_ARM_MOVT_ABS
1312 #define R_ARM_MOVT_ABS          44
1313 #endif
1314
1315 #ifndef R_ARM_THM_MOVW_ABS_NC
1316 #define R_ARM_THM_MOVW_ABS_NC   47
1317 #endif
1318
1319 #ifndef R_ARM_THM_MOVT_ABS
1320 #define R_ARM_THM_MOVT_ABS      48
1321 #endif
1322
1323 #ifndef R_ARM_THM_JUMP19
1324 #define R_ARM_THM_JUMP19        51
1325 #endif
1326
1327 static int32_t sign_extend32(int32_t value, int index)
1328 {
1329         uint8_t shift = 31 - index;
1330
1331         return (int32_t)(value << shift) >> shift;
1332 }
1333
1334 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1335 {
1336         uint32_t inst, upper, lower, sign, j1, j2;
1337         int32_t offset;
1338
1339         switch (r_type) {
1340         case R_ARM_ABS32:
1341         case R_ARM_REL32:
1342                 inst = TO_NATIVE(*(uint32_t *)loc);
1343                 return inst + sym->st_value;
1344         case R_ARM_MOVW_ABS_NC:
1345         case R_ARM_MOVT_ABS:
1346                 inst = TO_NATIVE(*(uint32_t *)loc);
1347                 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1348                                        15);
1349                 return offset + sym->st_value;
1350         case R_ARM_PC24:
1351         case R_ARM_CALL:
1352         case R_ARM_JUMP24:
1353                 inst = TO_NATIVE(*(uint32_t *)loc);
1354                 offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1355                 return offset + sym->st_value + 8;
1356         case R_ARM_THM_MOVW_ABS_NC:
1357         case R_ARM_THM_MOVT_ABS:
1358                 upper = TO_NATIVE(*(uint16_t *)loc);
1359                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1360                 offset = sign_extend32(((upper & 0x000f) << 12) |
1361                                        ((upper & 0x0400) << 1) |
1362                                        ((lower & 0x7000) >> 4) |
1363                                        (lower & 0x00ff),
1364                                        15);
1365                 return offset + sym->st_value;
1366         case R_ARM_THM_JUMP19:
1367                 /*
1368                  * Encoding T3:
1369                  * S     = upper[10]
1370                  * imm6  = upper[5:0]
1371                  * J1    = lower[13]
1372                  * J2    = lower[11]
1373                  * imm11 = lower[10:0]
1374                  * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1375                  */
1376                 upper = TO_NATIVE(*(uint16_t *)loc);
1377                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1378
1379                 sign = (upper >> 10) & 1;
1380                 j1 = (lower >> 13) & 1;
1381                 j2 = (lower >> 11) & 1;
1382                 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1383                                        ((upper & 0x03f) << 12) |
1384                                        ((lower & 0x07ff) << 1),
1385                                        20);
1386                 return offset + sym->st_value + 4;
1387         case R_ARM_THM_CALL:
1388         case R_ARM_THM_JUMP24:
1389                 /*
1390                  * Encoding T4:
1391                  * S     = upper[10]
1392                  * imm10 = upper[9:0]
1393                  * J1    = lower[13]
1394                  * J2    = lower[11]
1395                  * imm11 = lower[10:0]
1396                  * I1    = NOT(J1 XOR S)
1397                  * I2    = NOT(J2 XOR S)
1398                  * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1399                  */
1400                 upper = TO_NATIVE(*(uint16_t *)loc);
1401                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1402
1403                 sign = (upper >> 10) & 1;
1404                 j1 = (lower >> 13) & 1;
1405                 j2 = (lower >> 11) & 1;
1406                 offset = sign_extend32((sign << 24) |
1407                                        ((~(j1 ^ sign) & 1) << 23) |
1408                                        ((~(j2 ^ sign) & 1) << 22) |
1409                                        ((upper & 0x03ff) << 12) |
1410                                        ((lower & 0x07ff) << 1),
1411                                        24);
1412                 return offset + sym->st_value + 4;
1413         }
1414
1415         return (Elf_Addr)(-1);
1416 }
1417
1418 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1419 {
1420         uint32_t inst;
1421
1422         inst = TO_NATIVE(*location);
1423         switch (r_type) {
1424         case R_MIPS_LO16:
1425                 return inst & 0xffff;
1426         case R_MIPS_26:
1427                 return (inst & 0x03ffffff) << 2;
1428         case R_MIPS_32:
1429                 return inst;
1430         }
1431         return (Elf_Addr)(-1);
1432 }
1433
1434 #ifndef EM_RISCV
1435 #define EM_RISCV                243
1436 #endif
1437
1438 #ifndef R_RISCV_SUB32
1439 #define R_RISCV_SUB32           39
1440 #endif
1441
1442 #ifndef EM_LOONGARCH
1443 #define EM_LOONGARCH            258
1444 #endif
1445
1446 #ifndef R_LARCH_SUB32
1447 #define R_LARCH_SUB32           55
1448 #endif
1449
1450 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1451                                  unsigned int *r_type, unsigned int *r_sym)
1452 {
1453         typedef struct {
1454                 Elf64_Word    r_sym;    /* Symbol index */
1455                 unsigned char r_ssym;   /* Special symbol for 2nd relocation */
1456                 unsigned char r_type3;  /* 3rd relocation type */
1457                 unsigned char r_type2;  /* 2nd relocation type */
1458                 unsigned char r_type;   /* 1st relocation type */
1459         } Elf64_Mips_R_Info;
1460
1461         bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1462
1463         if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1464                 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1465
1466                 *r_type = mips64_r_info->r_type;
1467                 *r_sym = TO_NATIVE(mips64_r_info->r_sym);
1468                 return;
1469         }
1470
1471         if (is_64bit) {
1472                 Elf64_Xword r_info64 = r_info;
1473
1474                 r_info = TO_NATIVE(r_info64);
1475         } else {
1476                 Elf32_Word r_info32 = r_info;
1477
1478                 r_info = TO_NATIVE(r_info32);
1479         }
1480
1481         *r_type = ELF_R_TYPE(r_info);
1482         *r_sym = ELF_R_SYM(r_info);
1483 }
1484
1485 static void section_rela(struct module *mod, struct elf_info *elf,
1486                          Elf_Shdr *sechdr)
1487 {
1488         Elf_Rela *rela;
1489         unsigned int fsecndx = sechdr->sh_info;
1490         const char *fromsec = sec_name(elf, fsecndx);
1491         Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1492         Elf_Rela *stop  = (void *)start + sechdr->sh_size;
1493
1494         /* if from section (name) is know good then skip it */
1495         if (match(fromsec, section_white_list))
1496                 return;
1497
1498         for (rela = start; rela < stop; rela++) {
1499                 Elf_Sym *tsym;
1500                 Elf_Addr taddr, r_offset;
1501                 unsigned int r_type, r_sym;
1502
1503                 r_offset = TO_NATIVE(rela->r_offset);
1504                 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1505
1506                 tsym = elf->symtab_start + r_sym;
1507                 taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1508
1509                 switch (elf->hdr->e_machine) {
1510                 case EM_RISCV:
1511                         if (!strcmp("__ex_table", fromsec) &&
1512                             r_type == R_RISCV_SUB32)
1513                                 continue;
1514                         break;
1515                 case EM_LOONGARCH:
1516                         if (!strcmp("__ex_table", fromsec) &&
1517                             r_type == R_LARCH_SUB32)
1518                                 continue;
1519                         break;
1520                 }
1521
1522                 check_section_mismatch(mod, elf, tsym,
1523                                        fsecndx, fromsec, r_offset, taddr);
1524         }
1525 }
1526
1527 static void section_rel(struct module *mod, struct elf_info *elf,
1528                         Elf_Shdr *sechdr)
1529 {
1530         Elf_Rel *rel;
1531         unsigned int fsecndx = sechdr->sh_info;
1532         const char *fromsec = sec_name(elf, fsecndx);
1533         Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1534         Elf_Rel *stop  = (void *)start + sechdr->sh_size;
1535
1536         /* if from section (name) is know good then skip it */
1537         if (match(fromsec, section_white_list))
1538                 return;
1539
1540         for (rel = start; rel < stop; rel++) {
1541                 Elf_Sym *tsym;
1542                 Elf_Addr taddr = 0, r_offset;
1543                 unsigned int r_type, r_sym;
1544                 void *loc;
1545
1546                 r_offset = TO_NATIVE(rel->r_offset);
1547                 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1548
1549                 loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1550                 tsym = elf->symtab_start + r_sym;
1551
1552                 switch (elf->hdr->e_machine) {
1553                 case EM_386:
1554                         taddr = addend_386_rel(loc, r_type);
1555                         break;
1556                 case EM_ARM:
1557                         taddr = addend_arm_rel(loc, tsym, r_type);
1558                         break;
1559                 case EM_MIPS:
1560                         taddr = addend_mips_rel(loc, r_type);
1561                         break;
1562                 default:
1563                         fatal("Please add code to calculate addend for this architecture\n");
1564                 }
1565
1566                 check_section_mismatch(mod, elf, tsym,
1567                                        fsecndx, fromsec, r_offset, taddr);
1568         }
1569 }
1570
1571 /**
1572  * A module includes a number of sections that are discarded
1573  * either when loaded or when used as built-in.
1574  * For loaded modules all functions marked __init and all data
1575  * marked __initdata will be discarded when the module has been initialized.
1576  * Likewise for modules used built-in the sections marked __exit
1577  * are discarded because __exit marked function are supposed to be called
1578  * only when a module is unloaded which never happens for built-in modules.
1579  * The check_sec_ref() function traverses all relocation records
1580  * to find all references to a section that reference a section that will
1581  * be discarded and warns about it.
1582  **/
1583 static void check_sec_ref(struct module *mod, struct elf_info *elf)
1584 {
1585         int i;
1586         Elf_Shdr *sechdrs = elf->sechdrs;
1587
1588         /* Walk through all sections */
1589         for (i = 0; i < elf->num_sections; i++) {
1590                 check_section(mod->name, elf, &elf->sechdrs[i]);
1591                 /* We want to process only relocation sections and not .init */
1592                 if (sechdrs[i].sh_type == SHT_RELA)
1593                         section_rela(mod, elf, &elf->sechdrs[i]);
1594                 else if (sechdrs[i].sh_type == SHT_REL)
1595                         section_rel(mod, elf, &elf->sechdrs[i]);
1596         }
1597 }
1598
1599 static char *remove_dot(char *s)
1600 {
1601         size_t n = strcspn(s, ".");
1602
1603         if (n && s[n]) {
1604                 size_t m = strspn(s + n + 1, "0123456789");
1605                 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1606                         s[n] = 0;
1607         }
1608         return s;
1609 }
1610
1611 /*
1612  * The CRCs are recorded in .*.cmd files in the form of:
1613  * #SYMVER <name> <crc>
1614  */
1615 static void extract_crcs_for_object(const char *object, struct module *mod)
1616 {
1617         char cmd_file[PATH_MAX];
1618         char *buf, *p;
1619         const char *base;
1620         int dirlen, ret;
1621
1622         base = strrchr(object, '/');
1623         if (base) {
1624                 base++;
1625                 dirlen = base - object;
1626         } else {
1627                 dirlen = 0;
1628                 base = object;
1629         }
1630
1631         ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1632                        dirlen, object, base);
1633         if (ret >= sizeof(cmd_file)) {
1634                 error("%s: too long path was truncated\n", cmd_file);
1635                 return;
1636         }
1637
1638         buf = read_text_file(cmd_file);
1639         p = buf;
1640
1641         while ((p = strstr(p, "\n#SYMVER "))) {
1642                 char *name;
1643                 size_t namelen;
1644                 unsigned int crc;
1645                 struct symbol *sym;
1646
1647                 name = p + strlen("\n#SYMVER ");
1648
1649                 p = strchr(name, ' ');
1650                 if (!p)
1651                         break;
1652
1653                 namelen = p - name;
1654                 p++;
1655
1656                 if (!isdigit(*p))
1657                         continue;       /* skip this line */
1658
1659                 crc = strtoul(p, &p, 0);
1660                 if (*p != '\n')
1661                         continue;       /* skip this line */
1662
1663                 name[namelen] = '\0';
1664
1665                 /*
1666                  * sym_find_with_module() may return NULL here.
1667                  * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1668                  * Since commit e1327a127703, genksyms calculates CRCs of all
1669                  * symbols, including trimmed ones. Ignore orphan CRCs.
1670                  */
1671                 sym = sym_find_with_module(name, mod);
1672                 if (sym)
1673                         sym_set_crc(sym, crc);
1674         }
1675
1676         free(buf);
1677 }
1678
1679 /*
1680  * The symbol versions (CRC) are recorded in the .*.cmd files.
1681  * Parse them to retrieve CRCs for the current module.
1682  */
1683 static void mod_set_crcs(struct module *mod)
1684 {
1685         char objlist[PATH_MAX];
1686         char *buf, *p, *obj;
1687         int ret;
1688
1689         if (mod->is_vmlinux) {
1690                 strcpy(objlist, ".vmlinux.objs");
1691         } else {
1692                 /* objects for a module are listed in the *.mod file. */
1693                 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1694                 if (ret >= sizeof(objlist)) {
1695                         error("%s: too long path was truncated\n", objlist);
1696                         return;
1697                 }
1698         }
1699
1700         buf = read_text_file(objlist);
1701         p = buf;
1702
1703         while ((obj = strsep(&p, "\n")) && obj[0])
1704                 extract_crcs_for_object(obj, mod);
1705
1706         free(buf);
1707 }
1708
1709 static void read_symbols(const char *modname)
1710 {
1711         const char *symname;
1712         char *version;
1713         char *license;
1714         char *namespace;
1715         struct module *mod;
1716         struct elf_info info = { };
1717         Elf_Sym *sym;
1718
1719         if (!parse_elf(&info, modname))
1720                 return;
1721
1722         if (!strends(modname, ".o")) {
1723                 error("%s: filename must be suffixed with .o\n", modname);
1724                 return;
1725         }
1726
1727         /* strip trailing .o */
1728         mod = new_module(modname, strlen(modname) - strlen(".o"));
1729
1730         if (!mod->is_vmlinux) {
1731                 license = get_modinfo(&info, "license");
1732                 if (!license)
1733                         error("missing MODULE_LICENSE() in %s\n", modname);
1734                 while (license) {
1735                         if (!license_is_gpl_compatible(license)) {
1736                                 mod->is_gpl_compatible = false;
1737                                 break;
1738                         }
1739                         license = get_next_modinfo(&info, "license", license);
1740                 }
1741
1742                 namespace = get_modinfo(&info, "import_ns");
1743                 while (namespace) {
1744                         add_namespace(&mod->imported_namespaces, namespace);
1745                         namespace = get_next_modinfo(&info, "import_ns",
1746                                                      namespace);
1747                 }
1748         }
1749
1750         if (extra_warn && !get_modinfo(&info, "description"))
1751                 warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1752         for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1753                 symname = remove_dot(info.strtab + sym->st_name);
1754
1755                 handle_symbol(mod, &info, sym, symname);
1756                 handle_moddevtable(mod, &info, sym, symname);
1757         }
1758
1759         check_sec_ref(mod, &info);
1760
1761         if (!mod->is_vmlinux) {
1762                 version = get_modinfo(&info, "version");
1763                 if (version || all_versions)
1764                         get_src_version(mod->name, mod->srcversion,
1765                                         sizeof(mod->srcversion) - 1);
1766         }
1767
1768         parse_elf_finish(&info);
1769
1770         if (modversions) {
1771                 /*
1772                  * Our trick to get versioning for module struct etc. - it's
1773                  * never passed as an argument to an exported function, so
1774                  * the automatic versioning doesn't pick it up, but it's really
1775                  * important anyhow.
1776                  */
1777                 sym_add_unresolved("module_layout", mod, false);
1778
1779                 mod_set_crcs(mod);
1780         }
1781 }
1782
1783 static void read_symbols_from_files(const char *filename)
1784 {
1785         FILE *in = stdin;
1786         char fname[PATH_MAX];
1787
1788         in = fopen(filename, "r");
1789         if (!in)
1790                 fatal("Can't open filenames file %s: %m", filename);
1791
1792         while (fgets(fname, PATH_MAX, in) != NULL) {
1793                 if (strends(fname, "\n"))
1794                         fname[strlen(fname)-1] = '\0';
1795                 read_symbols(fname);
1796         }
1797
1798         fclose(in);
1799 }
1800
1801 #define SZ 500
1802
1803 /* We first write the generated file into memory using the
1804  * following helper, then compare to the file on disk and
1805  * only update the later if anything changed */
1806
1807 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1808                                                       const char *fmt, ...)
1809 {
1810         char tmp[SZ];
1811         int len;
1812         va_list ap;
1813
1814         va_start(ap, fmt);
1815         len = vsnprintf(tmp, SZ, fmt, ap);
1816         buf_write(buf, tmp, len);
1817         va_end(ap);
1818 }
1819
1820 void buf_write(struct buffer *buf, const char *s, int len)
1821 {
1822         if (buf->size - buf->pos < len) {
1823                 buf->size += len + SZ;
1824                 buf->p = NOFAIL(realloc(buf->p, buf->size));
1825         }
1826         strncpy(buf->p + buf->pos, s, len);
1827         buf->pos += len;
1828 }
1829
1830 static void check_exports(struct module *mod)
1831 {
1832         struct symbol *s, *exp;
1833
1834         list_for_each_entry(s, &mod->unresolved_symbols, list) {
1835                 const char *basename;
1836                 exp = find_symbol(s->name);
1837                 if (!exp) {
1838                         if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1839                                 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR,
1840                                             "\"%s\" [%s.ko] undefined!\n",
1841                                             s->name, mod->name);
1842                         continue;
1843                 }
1844                 if (exp->module == mod) {
1845                         error("\"%s\" [%s.ko] was exported without definition\n",
1846                               s->name, mod->name);
1847                         continue;
1848                 }
1849
1850                 exp->used = true;
1851                 s->module = exp->module;
1852                 s->crc_valid = exp->crc_valid;
1853                 s->crc = exp->crc;
1854
1855                 basename = strrchr(mod->name, '/');
1856                 if (basename)
1857                         basename++;
1858                 else
1859                         basename = mod->name;
1860
1861                 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1862                         modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
1863                                     "module %s uses symbol %s from namespace %s, but does not import it.\n",
1864                                     basename, exp->name, exp->namespace);
1865                         add_namespace(&mod->missing_namespaces, exp->namespace);
1866                 }
1867
1868                 if (!mod->is_gpl_compatible && exp->is_gpl_only)
1869                         error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1870                               basename, exp->name);
1871         }
1872 }
1873
1874 static void handle_white_list_exports(const char *white_list)
1875 {
1876         char *buf, *p, *name;
1877
1878         buf = read_text_file(white_list);
1879         p = buf;
1880
1881         while ((name = strsep(&p, "\n"))) {
1882                 struct symbol *sym = find_symbol(name);
1883
1884                 if (sym)
1885                         sym->used = true;
1886         }
1887
1888         free(buf);
1889 }
1890
1891 static void check_modname_len(struct module *mod)
1892 {
1893         const char *mod_name;
1894
1895         mod_name = strrchr(mod->name, '/');
1896         if (mod_name == NULL)
1897                 mod_name = mod->name;
1898         else
1899                 mod_name++;
1900         if (strlen(mod_name) >= MODULE_NAME_LEN)
1901                 error("module name is too long [%s.ko]\n", mod->name);
1902 }
1903
1904 /**
1905  * Header for the generated file
1906  **/
1907 static void add_header(struct buffer *b, struct module *mod)
1908 {
1909         buf_printf(b, "#include <linux/module.h>\n");
1910         /*
1911          * Include build-salt.h after module.h in order to
1912          * inherit the definitions.
1913          */
1914         buf_printf(b, "#define INCLUDE_VERMAGIC\n");
1915         buf_printf(b, "#include <linux/build-salt.h>\n");
1916         buf_printf(b, "#include <linux/elfnote-lto.h>\n");
1917         buf_printf(b, "#include <linux/export-internal.h>\n");
1918         buf_printf(b, "#include <linux/vermagic.h>\n");
1919         buf_printf(b, "#include <linux/compiler.h>\n");
1920         buf_printf(b, "\n");
1921         buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n");
1922         buf_printf(b, "#include <asm/orc_header.h>\n");
1923         buf_printf(b, "ORC_HEADER;\n");
1924         buf_printf(b, "#endif\n");
1925         buf_printf(b, "\n");
1926         buf_printf(b, "BUILD_SALT;\n");
1927         buf_printf(b, "BUILD_LTO_INFO;\n");
1928         buf_printf(b, "\n");
1929         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1930         buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1931         buf_printf(b, "\n");
1932         buf_printf(b, "__visible struct module __this_module\n");
1933         buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1934         buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1935         if (mod->has_init)
1936                 buf_printf(b, "\t.init = init_module,\n");
1937         if (mod->has_cleanup)
1938                 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1939                               "\t.exit = cleanup_module,\n"
1940                               "#endif\n");
1941         buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1942         buf_printf(b, "};\n");
1943
1944         if (!external_module)
1945                 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1946
1947         buf_printf(b,
1948                    "\n"
1949                    "#ifdef CONFIG_RETPOLINE\n"
1950                    "MODULE_INFO(retpoline, \"Y\");\n"
1951                    "#endif\n");
1952
1953         if (strstarts(mod->name, "drivers/staging"))
1954                 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1955
1956         if (strstarts(mod->name, "tools/testing"))
1957                 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1958 }
1959
1960 static void add_exported_symbols(struct buffer *buf, struct module *mod)
1961 {
1962         struct symbol *sym;
1963
1964         /* generate struct for exported symbols */
1965         buf_printf(buf, "\n");
1966         list_for_each_entry(sym, &mod->exported_symbols, list) {
1967                 if (trim_unused_exports && !sym->used)
1968                         continue;
1969
1970                 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1971                            sym->is_func ? "FUNC" : "DATA", sym->name,
1972                            sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1973         }
1974
1975         if (!modversions)
1976                 return;
1977
1978         /* record CRCs for exported symbols */
1979         buf_printf(buf, "\n");
1980         list_for_each_entry(sym, &mod->exported_symbols, list) {
1981                 if (trim_unused_exports && !sym->used)
1982                         continue;
1983
1984                 if (!sym->crc_valid)
1985                         warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1986                              "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1987                              sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1988                              sym->name);
1989
1990                 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1991                            sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1992         }
1993 }
1994
1995 /**
1996  * Record CRCs for unresolved symbols
1997  **/
1998 static void add_versions(struct buffer *b, struct module *mod)
1999 {
2000         struct symbol *s;
2001
2002         if (!modversions)
2003                 return;
2004
2005         buf_printf(b, "\n");
2006         buf_printf(b, "static const struct modversion_info ____versions[]\n");
2007         buf_printf(b, "__used __section(\"__versions\") = {\n");
2008
2009         list_for_each_entry(s, &mod->unresolved_symbols, list) {
2010                 if (!s->module)
2011                         continue;
2012                 if (!s->crc_valid) {
2013                         warn("\"%s\" [%s.ko] has no CRC!\n",
2014                                 s->name, mod->name);
2015                         continue;
2016                 }
2017                 if (strlen(s->name) >= MODULE_NAME_LEN) {
2018                         error("too long symbol \"%s\" [%s.ko]\n",
2019                               s->name, mod->name);
2020                         break;
2021                 }
2022                 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
2023                            s->crc, s->name);
2024         }
2025
2026         buf_printf(b, "};\n");
2027 }
2028
2029 static void add_depends(struct buffer *b, struct module *mod)
2030 {
2031         struct symbol *s;
2032         int first = 1;
2033
2034         /* Clear ->seen flag of modules that own symbols needed by this. */
2035         list_for_each_entry(s, &mod->unresolved_symbols, list) {
2036                 if (s->module)
2037                         s->module->seen = s->module->is_vmlinux;
2038         }
2039
2040         buf_printf(b, "\n");
2041         buf_printf(b, "MODULE_INFO(depends, \"");
2042         list_for_each_entry(s, &mod->unresolved_symbols, list) {
2043                 const char *p;
2044                 if (!s->module)
2045                         continue;
2046
2047                 if (s->module->seen)
2048                         continue;
2049
2050                 s->module->seen = true;
2051                 p = strrchr(s->module->name, '/');
2052                 if (p)
2053                         p++;
2054                 else
2055                         p = s->module->name;
2056                 buf_printf(b, "%s%s", first ? "" : ",", p);
2057                 first = 0;
2058         }
2059         buf_printf(b, "\");\n");
2060 }
2061
2062 static void add_srcversion(struct buffer *b, struct module *mod)
2063 {
2064         if (mod->srcversion[0]) {
2065                 buf_printf(b, "\n");
2066                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2067                            mod->srcversion);
2068         }
2069 }
2070
2071 static void write_buf(struct buffer *b, const char *fname)
2072 {
2073         FILE *file;
2074
2075         if (error_occurred)
2076                 return;
2077
2078         file = fopen(fname, "w");
2079         if (!file) {
2080                 perror(fname);
2081                 exit(1);
2082         }
2083         if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2084                 perror(fname);
2085                 exit(1);
2086         }
2087         if (fclose(file) != 0) {
2088                 perror(fname);
2089                 exit(1);
2090         }
2091 }
2092
2093 static void write_if_changed(struct buffer *b, const char *fname)
2094 {
2095         char *tmp;
2096         FILE *file;
2097         struct stat st;
2098
2099         file = fopen(fname, "r");
2100         if (!file)
2101                 goto write;
2102
2103         if (fstat(fileno(file), &st) < 0)
2104                 goto close_write;
2105
2106         if (st.st_size != b->pos)
2107                 goto close_write;
2108
2109         tmp = NOFAIL(malloc(b->pos));
2110         if (fread(tmp, 1, b->pos, file) != b->pos)
2111                 goto free_write;
2112
2113         if (memcmp(tmp, b->p, b->pos) != 0)
2114                 goto free_write;
2115
2116         free(tmp);
2117         fclose(file);
2118         return;
2119
2120  free_write:
2121         free(tmp);
2122  close_write:
2123         fclose(file);
2124  write:
2125         write_buf(b, fname);
2126 }
2127
2128 static void write_vmlinux_export_c_file(struct module *mod)
2129 {
2130         struct buffer buf = { };
2131
2132         buf_printf(&buf,
2133                    "#include <linux/export-internal.h>\n");
2134
2135         add_exported_symbols(&buf, mod);
2136         write_if_changed(&buf, ".vmlinux.export.c");
2137         free(buf.p);
2138 }
2139
2140 /* do sanity checks, and generate *.mod.c file */
2141 static void write_mod_c_file(struct module *mod)
2142 {
2143         struct buffer buf = { };
2144         char fname[PATH_MAX];
2145         int ret;
2146
2147         add_header(&buf, mod);
2148         add_exported_symbols(&buf, mod);
2149         add_versions(&buf, mod);
2150         add_depends(&buf, mod);
2151         add_moddevtable(&buf, mod);
2152         add_srcversion(&buf, mod);
2153
2154         ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
2155         if (ret >= sizeof(fname)) {
2156                 error("%s: too long path was truncated\n", fname);
2157                 goto free;
2158         }
2159
2160         write_if_changed(&buf, fname);
2161
2162 free:
2163         free(buf.p);
2164 }
2165
2166 /* parse Module.symvers file. line format:
2167  * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
2168  **/
2169 static void read_dump(const char *fname)
2170 {
2171         char *buf, *pos, *line;
2172
2173         buf = read_text_file(fname);
2174         if (!buf)
2175                 /* No symbol versions, silently ignore */
2176                 return;
2177
2178         pos = buf;
2179
2180         while ((line = get_line(&pos))) {
2181                 char *symname, *namespace, *modname, *d, *export;
2182                 unsigned int crc;
2183                 struct module *mod;
2184                 struct symbol *s;
2185                 bool gpl_only;
2186
2187                 if (!(symname = strchr(line, '\t')))
2188                         goto fail;
2189                 *symname++ = '\0';
2190                 if (!(modname = strchr(symname, '\t')))
2191                         goto fail;
2192                 *modname++ = '\0';
2193                 if (!(export = strchr(modname, '\t')))
2194                         goto fail;
2195                 *export++ = '\0';
2196                 if (!(namespace = strchr(export, '\t')))
2197                         goto fail;
2198                 *namespace++ = '\0';
2199
2200                 crc = strtoul(line, &d, 16);
2201                 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2202                         goto fail;
2203
2204                 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2205                         gpl_only = true;
2206                 } else if (!strcmp(export, "EXPORT_SYMBOL")) {
2207                         gpl_only = false;
2208                 } else {
2209                         error("%s: unknown license %s. skip", symname, export);
2210                         continue;
2211                 }
2212
2213                 mod = find_module(modname);
2214                 if (!mod) {
2215                         mod = new_module(modname, strlen(modname));
2216                         mod->from_dump = true;
2217                 }
2218                 s = sym_add_exported(symname, mod, gpl_only, namespace);
2219                 sym_set_crc(s, crc);
2220         }
2221         free(buf);
2222         return;
2223 fail:
2224         free(buf);
2225         fatal("parse error in symbol dump file\n");
2226 }
2227
2228 static void write_dump(const char *fname)
2229 {
2230         struct buffer buf = { };
2231         struct module *mod;
2232         struct symbol *sym;
2233
2234         list_for_each_entry(mod, &modules, list) {
2235                 if (mod->from_dump)
2236                         continue;
2237                 list_for_each_entry(sym, &mod->exported_symbols, list) {
2238                         if (trim_unused_exports && !sym->used)
2239                                 continue;
2240
2241                         buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2242                                    sym->crc, sym->name, mod->name,
2243                                    sym->is_gpl_only ? "_GPL" : "",
2244                                    sym->namespace);
2245                 }
2246         }
2247         write_buf(&buf, fname);
2248         free(buf.p);
2249 }
2250
2251 static void write_namespace_deps_files(const char *fname)
2252 {
2253         struct module *mod;
2254         struct namespace_list *ns;
2255         struct buffer ns_deps_buf = {};
2256
2257         list_for_each_entry(mod, &modules, list) {
2258
2259                 if (mod->from_dump || list_empty(&mod->missing_namespaces))
2260                         continue;
2261
2262                 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2263
2264                 list_for_each_entry(ns, &mod->missing_namespaces, list)
2265                         buf_printf(&ns_deps_buf, " %s", ns->namespace);
2266
2267                 buf_printf(&ns_deps_buf, "\n");
2268         }
2269
2270         write_if_changed(&ns_deps_buf, fname);
2271         free(ns_deps_buf.p);
2272 }
2273
2274 struct dump_list {
2275         struct list_head list;
2276         const char *file;
2277 };
2278
2279 int main(int argc, char **argv)
2280 {
2281         struct module *mod;
2282         char *missing_namespace_deps = NULL;
2283         char *unused_exports_white_list = NULL;
2284         char *dump_write = NULL, *files_source = NULL;
2285         int opt;
2286         LIST_HEAD(dump_lists);
2287         struct dump_list *dl, *dl2;
2288
2289         while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
2290                 switch (opt) {
2291                 case 'e':
2292                         external_module = true;
2293                         break;
2294                 case 'i':
2295                         dl = NOFAIL(malloc(sizeof(*dl)));
2296                         dl->file = optarg;
2297                         list_add_tail(&dl->list, &dump_lists);
2298                         break;
2299                 case 'M':
2300                         module_enabled = true;
2301                         break;
2302                 case 'm':
2303                         modversions = true;
2304                         break;
2305                 case 'n':
2306                         ignore_missing_files = true;
2307                         break;
2308                 case 'o':
2309                         dump_write = optarg;
2310                         break;
2311                 case 'a':
2312                         all_versions = true;
2313                         break;
2314                 case 'T':
2315                         files_source = optarg;
2316                         break;
2317                 case 't':
2318                         trim_unused_exports = true;
2319                         break;
2320                 case 'u':
2321                         unused_exports_white_list = optarg;
2322                         break;
2323                 case 'W':
2324                         extra_warn = true;
2325                         break;
2326                 case 'w':
2327                         warn_unresolved = true;
2328                         break;
2329                 case 'E':
2330                         sec_mismatch_warn_only = false;
2331                         break;
2332                 case 'N':
2333                         allow_missing_ns_imports = true;
2334                         break;
2335                 case 'd':
2336                         missing_namespace_deps = optarg;
2337                         break;
2338                 default:
2339                         exit(1);
2340                 }
2341         }
2342
2343         list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2344                 read_dump(dl->file);
2345                 list_del(&dl->list);
2346                 free(dl);
2347         }
2348
2349         while (optind < argc)
2350                 read_symbols(argv[optind++]);
2351
2352         if (files_source)
2353                 read_symbols_from_files(files_source);
2354
2355         list_for_each_entry(mod, &modules, list) {
2356                 if (mod->from_dump || mod->is_vmlinux)
2357                         continue;
2358
2359                 check_modname_len(mod);
2360                 check_exports(mod);
2361         }
2362
2363         if (unused_exports_white_list)
2364                 handle_white_list_exports(unused_exports_white_list);
2365
2366         list_for_each_entry(mod, &modules, list) {
2367                 if (mod->from_dump)
2368                         continue;
2369
2370                 if (mod->is_vmlinux)
2371                         write_vmlinux_export_c_file(mod);
2372                 else
2373                         write_mod_c_file(mod);
2374         }
2375
2376         if (missing_namespace_deps)
2377                 write_namespace_deps_files(missing_namespace_deps);
2378
2379         if (dump_write)
2380                 write_dump(dump_write);
2381         if (sec_mismatch_count && !sec_mismatch_warn_only)
2382                 error("Section mismatches detected.\n"
2383                       "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2384
2385         if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2386                 warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2387                      nr_unresolved - MAX_UNRESOLVED_REPORTS);
2388
2389         return error_occurred ? 1 : 0;
2390 }